From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- gcc/ada/gcc-interface/decl.c | 8853 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 8853 insertions(+) create mode 100644 gcc/ada/gcc-interface/decl.c (limited to 'gcc/ada/gcc-interface/decl.c') diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c new file mode 100644 index 000000000..239483425 --- /dev/null +++ b/gcc/ada/gcc-interface/decl.c @@ -0,0 +1,8853 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * D E C L * + * * + * C Implementation File * + * * + * Copyright (C) 1992-2011, Free Software Foundation, Inc. * + * * + * GNAT is free software; you can redistribute it and/or modify it under * + * terms of the GNU General Public License as published by the Free Soft- * + * ware Foundation; either version 3, or (at your option) any later ver- * + * sion. GNAT is distributed in the hope that it will be useful, but WITH- * + * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * + * for more details. You should have received a copy of the GNU General * + * Public License along with GCC; see the file COPYING3. If not see * + * . * + * * + * GNAT was originally developed by the GNAT team at New York University. * + * Extensive contributions were provided by Ada Core Technologies Inc. * + * * + ****************************************************************************/ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "flags.h" +#include "toplev.h" +#include "ggc.h" +#include "target.h" +#include "tree-inline.h" + +#include "ada.h" +#include "types.h" +#include "atree.h" +#include "elists.h" +#include "namet.h" +#include "nlists.h" +#include "repinfo.h" +#include "snames.h" +#include "stringt.h" +#include "uintp.h" +#include "fe.h" +#include "sinfo.h" +#include "einfo.h" +#include "ada-tree.h" +#include "gigi.h" + +/* Convention_Stdcall should be processed in a specific way on 32 bits + Windows targets only. The macro below is a helper to avoid having to + check for a Windows specific attribute throughout this unit. */ + +#if TARGET_DLLIMPORT_DECL_ATTRIBUTES +#ifdef TARGET_64BIT +#define Has_Stdcall_Convention(E) \ + (!TARGET_64BIT && Convention (E) == Convention_Stdcall) +#else +#define Has_Stdcall_Convention(E) (Convention (E) == Convention_Stdcall) +#endif +#else +#define Has_Stdcall_Convention(E) 0 +#endif + +/* Stack realignment is necessary for functions with foreign conventions when + the ABI doesn't mandate as much as what the compiler assumes - that is, up + to PREFERRED_STACK_BOUNDARY. + + Such realignment can be requested with a dedicated function type attribute + on the targets that support it. We define FOREIGN_FORCE_REALIGN_STACK to + characterize the situations where the attribute should be set. We rely on + compiler configuration settings for 'main' to decide. */ + +#ifdef MAIN_STACK_BOUNDARY +#define FOREIGN_FORCE_REALIGN_STACK \ + (MAIN_STACK_BOUNDARY < PREFERRED_STACK_BOUNDARY) +#else +#define FOREIGN_FORCE_REALIGN_STACK 0 +#endif + +struct incomplete +{ + struct incomplete *next; + tree old_type; + Entity_Id full_type; +}; + +/* These variables are used to defer recursively expanding incomplete types + while we are processing an array, a record or a subprogram type. */ +static int defer_incomplete_level = 0; +static struct incomplete *defer_incomplete_list; + +/* This variable is used to delay expanding From_With_Type types until the + end of the spec. */ +static struct incomplete *defer_limited_with; + +/* These variables are used to defer finalizing types. The element of the + list is the TYPE_DECL associated with the type. */ +static int defer_finalize_level = 0; +static VEC (tree,heap) *defer_finalize_list; + +typedef struct subst_pair_d { + tree discriminant; + tree replacement; +} subst_pair; + +DEF_VEC_O(subst_pair); +DEF_VEC_ALLOC_O(subst_pair,heap); + +typedef struct variant_desc_d { + /* The type of the variant. */ + tree type; + + /* The associated field. */ + tree field; + + /* The value of the qualifier. */ + tree qual; + + /* The type of the variant after transformation. */ + tree new_type; +} variant_desc; + +DEF_VEC_O(variant_desc); +DEF_VEC_ALLOC_O(variant_desc,heap); + +/* A hash table used to cache the result of annotate_value. */ +static GTY ((if_marked ("tree_int_map_marked_p"), + param_is (struct tree_int_map))) htab_t annotate_value_cache; + +enum alias_set_op +{ + ALIAS_SET_COPY, + ALIAS_SET_SUBSET, + ALIAS_SET_SUPERSET +}; + +static void relate_alias_sets (tree, tree, enum alias_set_op); + +static bool allocatable_size_p (tree, bool); +static void prepend_one_attribute_to (struct attrib **, + enum attr_type, tree, tree, Node_Id); +static void prepend_attributes (Entity_Id, struct attrib **); +static tree elaborate_expression (Node_Id, Entity_Id, tree, bool, bool, bool); +static bool is_variable_size (tree); +static tree elaborate_expression_1 (tree, Entity_Id, tree, bool, bool); +static tree elaborate_expression_2 (tree, Entity_Id, tree, bool, bool, + unsigned int); +static tree make_packable_type (tree, bool); +static tree gnat_to_gnu_component_type (Entity_Id, bool, bool); +static tree gnat_to_gnu_param (Entity_Id, Mechanism_Type, Entity_Id, bool, + bool *); +static tree gnat_to_gnu_field (Entity_Id, tree, int, bool, bool); +static bool same_discriminant_p (Entity_Id, Entity_Id); +static bool array_type_has_nonaliased_component (tree, Entity_Id); +static bool compile_time_known_address_p (Node_Id); +static bool cannot_be_superflat_p (Node_Id); +static bool constructor_address_p (tree); +static void components_to_record (tree, Node_Id, tree, int, bool, tree *, + bool, bool, bool, bool, bool); +static Uint annotate_value (tree); +static void annotate_rep (Entity_Id, tree); +static tree build_position_list (tree, bool, tree, tree, unsigned int, tree); +static VEC(subst_pair,heap) *build_subst_list (Entity_Id, Entity_Id, bool); +static VEC(variant_desc,heap) *build_variant_list (tree, + VEC(subst_pair,heap) *, + VEC(variant_desc,heap) *); +static tree validate_size (Uint, tree, Entity_Id, enum tree_code, bool, bool); +static void set_rm_size (Uint, tree, Entity_Id); +static tree make_type_from_size (tree, tree, bool); +static unsigned int validate_alignment (Uint, Entity_Id, unsigned int); +static unsigned int ceil_alignment (unsigned HOST_WIDE_INT); +static void check_ok_for_atomic (tree, Entity_Id, bool); +static tree create_field_decl_from (tree, tree, tree, tree, tree, + VEC(subst_pair,heap) *); +static tree get_rep_part (tree); +static tree create_variant_part_from (tree, VEC(variant_desc,heap) *, tree, + tree, VEC(subst_pair,heap) *); +static void copy_and_substitute_in_size (tree, tree, VEC(subst_pair,heap) *); +static void rest_of_type_decl_compilation_no_defer (tree); +static void finish_fat_pointer_type (tree, tree); + +/* The relevant constituents of a subprogram binding to a GCC builtin. Used + to pass around calls performing profile compatibility checks. */ + +typedef struct { + Entity_Id gnat_entity; /* The Ada subprogram entity. */ + tree ada_fntype; /* The corresponding GCC type node. */ + tree btin_fntype; /* The GCC builtin function type node. */ +} intrin_binding_t; + +static bool intrin_profiles_compatible_p (intrin_binding_t *); + +/* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada + entity, return the equivalent GCC tree for that entity (a ..._DECL node) + and associate the ..._DECL node with the input GNAT defining identifier. + + If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its + initial value (in GCC tree form). This is optional for a variable. For + a renamed entity, GNU_EXPR gives the object being renamed. + + DEFINITION is nonzero if this call is intended for a definition. This is + used for separate compilation where it is necessary to know whether an + external declaration or a definition must be created if the GCC equivalent + was not created previously. The value of 1 is normally used for a nonzero + DEFINITION, but a value of 2 is used in special circumstances, defined in + the code. */ + +tree +gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition) +{ + /* Contains the kind of the input GNAT node. */ + const Entity_Kind kind = Ekind (gnat_entity); + /* True if this is a type. */ + const bool is_type = IN (kind, Type_Kind); + /* True if debug info is requested for this entity. */ + const bool debug_info_p = Needs_Debug_Info (gnat_entity); + /* True if this entity is to be considered as imported. */ + const bool imported_p + = (Is_Imported (gnat_entity) && No (Address_Clause (gnat_entity))); + /* For a type, contains the equivalent GNAT node to be used in gigi. */ + Entity_Id gnat_equiv_type = Empty; + /* Temporary used to walk the GNAT tree. */ + Entity_Id gnat_temp; + /* Contains the GCC DECL node which is equivalent to the input GNAT node. + This node will be associated with the GNAT node by calling at the end + of the `switch' statement. */ + tree gnu_decl = NULL_TREE; + /* Contains the GCC type to be used for the GCC node. */ + tree gnu_type = NULL_TREE; + /* Contains the GCC size tree to be used for the GCC node. */ + tree gnu_size = NULL_TREE; + /* Contains the GCC name to be used for the GCC node. */ + tree gnu_entity_name; + /* True if we have already saved gnu_decl as a GNAT association. */ + bool saved = false; + /* True if we incremented defer_incomplete_level. */ + bool this_deferred = false; + /* True if we incremented force_global. */ + bool this_global = false; + /* True if we should check to see if elaborated during processing. */ + bool maybe_present = false; + /* True if we made GNU_DECL and its type here. */ + bool this_made_decl = false; + /* Size and alignment of the GCC node, if meaningful. */ + unsigned int esize = 0, align = 0; + /* Contains the list of attributes directly attached to the entity. */ + struct attrib *attr_list = NULL; + + /* Since a use of an Itype is a definition, process it as such if it + is not in a with'ed unit. */ + if (!definition + && is_type + && Is_Itype (gnat_entity) + && !present_gnu_tree (gnat_entity) + && In_Extended_Main_Code_Unit (gnat_entity)) + { + /* Ensure that we are in a subprogram mentioned in the Scope chain of + this entity, our current scope is global, or we encountered a task + or entry (where we can't currently accurately check scoping). */ + if (!current_function_decl + || DECL_ELABORATION_PROC_P (current_function_decl)) + { + process_type (gnat_entity); + return get_gnu_tree (gnat_entity); + } + + for (gnat_temp = Scope (gnat_entity); + Present (gnat_temp); + gnat_temp = Scope (gnat_temp)) + { + if (Is_Type (gnat_temp)) + gnat_temp = Underlying_Type (gnat_temp); + + if (Ekind (gnat_temp) == E_Subprogram_Body) + gnat_temp + = Corresponding_Spec (Parent (Declaration_Node (gnat_temp))); + + if (IN (Ekind (gnat_temp), Subprogram_Kind) + && Present (Protected_Body_Subprogram (gnat_temp))) + gnat_temp = Protected_Body_Subprogram (gnat_temp); + + if (Ekind (gnat_temp) == E_Entry + || Ekind (gnat_temp) == E_Entry_Family + || Ekind (gnat_temp) == E_Task_Type + || (IN (Ekind (gnat_temp), Subprogram_Kind) + && present_gnu_tree (gnat_temp) + && (current_function_decl + == gnat_to_gnu_entity (gnat_temp, NULL_TREE, 0)))) + { + process_type (gnat_entity); + return get_gnu_tree (gnat_entity); + } + } + + /* This abort means the Itype has an incorrect scope, i.e. that its + scope does not correspond to the subprogram it is declared in. */ + gcc_unreachable (); + } + + /* If we've already processed this entity, return what we got last time. + If we are defining the node, we should not have already processed it. + In that case, we will abort below when we try to save a new GCC tree + for this object. We also need to handle the case of getting a dummy + type when a Full_View exists. */ + if ((!definition || (is_type && imported_p)) + && present_gnu_tree (gnat_entity)) + { + gnu_decl = get_gnu_tree (gnat_entity); + + if (TREE_CODE (gnu_decl) == TYPE_DECL + && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl)) + && IN (kind, Incomplete_Or_Private_Kind) + && Present (Full_View (gnat_entity))) + { + gnu_decl + = gnat_to_gnu_entity (Full_View (gnat_entity), NULL_TREE, 0); + save_gnu_tree (gnat_entity, NULL_TREE, false); + save_gnu_tree (gnat_entity, gnu_decl, false); + } + + return gnu_decl; + } + + /* If this is a numeric or enumeral type, or an access type, a nonzero + Esize must be specified unless it was specified by the programmer. */ + gcc_assert (!Unknown_Esize (gnat_entity) + || Has_Size_Clause (gnat_entity) + || (!IN (kind, Numeric_Kind) + && !IN (kind, Enumeration_Kind) + && (!IN (kind, Access_Kind) + || kind == E_Access_Protected_Subprogram_Type + || kind == E_Anonymous_Access_Protected_Subprogram_Type + || kind == E_Access_Subtype))); + + /* The RM size must be specified for all discrete and fixed-point types. */ + gcc_assert (!(IN (kind, Discrete_Or_Fixed_Point_Kind) + && Unknown_RM_Size (gnat_entity))); + + /* If we get here, it means we have not yet done anything with this entity. + If we are not defining it, it must be a type or an entity that is defined + elsewhere or externally, otherwise we should have defined it already. */ + gcc_assert (definition + || type_annotate_only + || is_type + || kind == E_Discriminant + || kind == E_Component + || kind == E_Label + || (kind == E_Constant && Present (Full_View (gnat_entity))) + || Is_Public (gnat_entity)); + + /* Get the name of the entity and set up the line number and filename of + the original definition for use in any decl we make. */ + gnu_entity_name = get_entity_name (gnat_entity); + Sloc_to_locus (Sloc (gnat_entity), &input_location); + + /* For cases when we are not defining (i.e., we are referencing from + another compilation unit) public entities, show we are at global level + for the purpose of computing scopes. Don't do this for components or + discriminants since the relevant test is whether or not the record is + being defined. Don't do this for constants either as we'll look into + their defining expression in the local context. */ + if (!definition + && kind != E_Component + && kind != E_Discriminant + && kind != E_Constant + && Is_Public (gnat_entity) + && !Is_Statically_Allocated (gnat_entity)) + force_global++, this_global = true; + + /* Handle any attributes directly attached to the entity. */ + if (Has_Gigi_Rep_Item (gnat_entity)) + prepend_attributes (gnat_entity, &attr_list); + + /* Do some common processing for types. */ + if (is_type) + { + /* Compute the equivalent type to be used in gigi. */ + gnat_equiv_type = Gigi_Equivalent_Type (gnat_entity); + + /* Machine_Attributes on types are expected to be propagated to + subtypes. The corresponding Gigi_Rep_Items are only attached + to the first subtype though, so we handle the propagation here. */ + if (Base_Type (gnat_entity) != gnat_entity + && !Is_First_Subtype (gnat_entity) + && Has_Gigi_Rep_Item (First_Subtype (Base_Type (gnat_entity)))) + prepend_attributes (First_Subtype (Base_Type (gnat_entity)), + &attr_list); + + /* Compute a default value for the size of the type. */ + if (Known_Esize (gnat_entity) + && UI_Is_In_Int_Range (Esize (gnat_entity))) + { + unsigned int max_esize; + esize = UI_To_Int (Esize (gnat_entity)); + + if (IN (kind, Float_Kind)) + max_esize = fp_prec_to_size (LONG_DOUBLE_TYPE_SIZE); + else if (IN (kind, Access_Kind)) + max_esize = POINTER_SIZE * 2; + else + max_esize = LONG_LONG_TYPE_SIZE; + + if (esize > max_esize) + esize = max_esize; + } + else + esize = LONG_LONG_TYPE_SIZE; + } + + switch (kind) + { + case E_Constant: + /* If this is a use of a deferred constant without address clause, + get its full definition. */ + if (!definition + && No (Address_Clause (gnat_entity)) + && Present (Full_View (gnat_entity))) + { + gnu_decl + = gnat_to_gnu_entity (Full_View (gnat_entity), gnu_expr, 0); + saved = true; + break; + } + + /* If we have an external constant that we are not defining, get the + expression that is was defined to represent. We may throw it away + later if it is not a constant. But do not retrieve the expression + if it is an allocator because the designated type might be dummy + at this point. */ + if (!definition + && !No_Initialization (Declaration_Node (gnat_entity)) + && Present (Expression (Declaration_Node (gnat_entity))) + && Nkind (Expression (Declaration_Node (gnat_entity))) + != N_Allocator) + { + bool went_into_elab_proc = false; + + /* The expression may contain N_Expression_With_Actions nodes and + thus object declarations from other units. In this case, even + though the expression will eventually be discarded since not a + constant, the declarations would be stuck either in the global + varpool or in the current scope. Therefore we force the local + context and create a fake scope that we'll zap at the end. */ + if (!current_function_decl) + { + current_function_decl = get_elaboration_procedure (); + went_into_elab_proc = true; + } + gnat_pushlevel (); + + gnu_expr = gnat_to_gnu (Expression (Declaration_Node (gnat_entity))); + + gnat_zaplevel (); + if (went_into_elab_proc) + current_function_decl = NULL_TREE; + } + + /* Ignore deferred constant definitions without address clause since + they are processed fully in the front-end. If No_Initialization + is set, this is not a deferred constant but a constant whose value + is built manually. And constants that are renamings are handled + like variables. */ + if (definition + && !gnu_expr + && No (Address_Clause (gnat_entity)) + && !No_Initialization (Declaration_Node (gnat_entity)) + && No (Renamed_Object (gnat_entity))) + { + gnu_decl = error_mark_node; + saved = true; + break; + } + + /* Ignore constant definitions already marked with the error node. See + the N_Object_Declaration case of gnat_to_gnu for the rationale. */ + if (definition + && gnu_expr + && present_gnu_tree (gnat_entity) + && get_gnu_tree (gnat_entity) == error_mark_node) + { + maybe_present = true; + break; + } + + goto object; + + case E_Exception: + /* We used to special case VMS exceptions here to directly map them to + their associated condition code. Since this code had to be masked + dynamically to strip off the severity bits, this caused trouble in + the GCC/ZCX case because the "type" pointers we store in the tables + have to be static. We now don't special case here anymore, and let + the regular processing take place, which leaves us with a regular + exception data object for VMS exceptions too. The condition code + mapping is taken care of by the front end and the bitmasking by the + run-time library. */ + goto object; + + case E_Discriminant: + case E_Component: + { + /* The GNAT record where the component was defined. */ + Entity_Id gnat_record = Underlying_Type (Scope (gnat_entity)); + + /* If the variable is an inherited record component (in the case of + extended record types), just return the inherited entity, which + must be a FIELD_DECL. Likewise for discriminants. + For discriminants of untagged records which have explicit + stored discriminants, return the entity for the corresponding + stored discriminant. Also use Original_Record_Component + if the record has a private extension. */ + if (Present (Original_Record_Component (gnat_entity)) + && Original_Record_Component (gnat_entity) != gnat_entity) + { + gnu_decl + = gnat_to_gnu_entity (Original_Record_Component (gnat_entity), + gnu_expr, definition); + saved = true; + break; + } + + /* If the enclosing record has explicit stored discriminants, + then it is an untagged record. If the Corresponding_Discriminant + is not empty then this must be a renamed discriminant and its + Original_Record_Component must point to the corresponding explicit + stored discriminant (i.e. we should have taken the previous + branch). */ + else if (Present (Corresponding_Discriminant (gnat_entity)) + && Is_Tagged_Type (gnat_record)) + { + /* A tagged record has no explicit stored discriminants. */ + gcc_assert (First_Discriminant (gnat_record) + == First_Stored_Discriminant (gnat_record)); + gnu_decl + = gnat_to_gnu_entity (Corresponding_Discriminant (gnat_entity), + gnu_expr, definition); + saved = true; + break; + } + + else if (Present (CR_Discriminant (gnat_entity)) + && type_annotate_only) + { + gnu_decl = gnat_to_gnu_entity (CR_Discriminant (gnat_entity), + gnu_expr, definition); + saved = true; + break; + } + + /* If the enclosing record has explicit stored discriminants, then + it is an untagged record. If the Corresponding_Discriminant + is not empty then this must be a renamed discriminant and its + Original_Record_Component must point to the corresponding explicit + stored discriminant (i.e. we should have taken the first + branch). */ + else if (Present (Corresponding_Discriminant (gnat_entity)) + && (First_Discriminant (gnat_record) + != First_Stored_Discriminant (gnat_record))) + gcc_unreachable (); + + /* Otherwise, if we are not defining this and we have no GCC type + for the containing record, make one for it. Then we should + have made our own equivalent. */ + else if (!definition && !present_gnu_tree (gnat_record)) + { + /* ??? If this is in a record whose scope is a protected + type and we have an Original_Record_Component, use it. + This is a workaround for major problems in protected type + handling. */ + Entity_Id Scop = Scope (Scope (gnat_entity)); + if ((Is_Protected_Type (Scop) + || (Is_Private_Type (Scop) + && Present (Full_View (Scop)) + && Is_Protected_Type (Full_View (Scop)))) + && Present (Original_Record_Component (gnat_entity))) + { + gnu_decl + = gnat_to_gnu_entity (Original_Record_Component + (gnat_entity), + gnu_expr, 0); + saved = true; + break; + } + + gnat_to_gnu_entity (Scope (gnat_entity), NULL_TREE, 0); + gnu_decl = get_gnu_tree (gnat_entity); + saved = true; + break; + } + + else + /* Here we have no GCC type and this is a reference rather than a + definition. This should never happen. Most likely the cause is + reference before declaration in the gnat tree for gnat_entity. */ + gcc_unreachable (); + } + + case E_Loop_Parameter: + case E_Out_Parameter: + case E_Variable: + + /* Simple variables, loop variables, Out parameters and exceptions. */ + object: + { + bool const_flag + = ((kind == E_Constant || kind == E_Variable) + && Is_True_Constant (gnat_entity) + && !Treat_As_Volatile (gnat_entity) + && (((Nkind (Declaration_Node (gnat_entity)) + == N_Object_Declaration) + && Present (Expression (Declaration_Node (gnat_entity)))) + || Present (Renamed_Object (gnat_entity)) + || imported_p)); + bool inner_const_flag = const_flag; + bool static_p = Is_Statically_Allocated (gnat_entity); + bool mutable_p = false; + bool used_by_ref = false; + tree gnu_ext_name = NULL_TREE; + tree renamed_obj = NULL_TREE; + tree gnu_object_size; + + if (Present (Renamed_Object (gnat_entity)) && !definition) + { + if (kind == E_Exception) + gnu_expr = gnat_to_gnu_entity (Renamed_Entity (gnat_entity), + NULL_TREE, 0); + else + gnu_expr = gnat_to_gnu (Renamed_Object (gnat_entity)); + } + + /* Get the type after elaborating the renamed object. */ + gnu_type = gnat_to_gnu_type (Etype (gnat_entity)); + + /* If this is a standard exception definition, then use the standard + exception type. This is necessary to make sure that imported and + exported views of exceptions are properly merged in LTO mode. */ + if (TREE_CODE (TYPE_NAME (gnu_type)) == TYPE_DECL + && DECL_NAME (TYPE_NAME (gnu_type)) == exception_data_name_id) + gnu_type = except_type_node; + + /* For a debug renaming declaration, build a debug-only entity. */ + if (Present (Debug_Renaming_Link (gnat_entity))) + { + /* Force a non-null value to make sure the symbol is retained. */ + tree value = build1 (INDIRECT_REF, gnu_type, + build1 (NOP_EXPR, + build_pointer_type (gnu_type), + integer_minus_one_node)); + gnu_decl = build_decl (input_location, + VAR_DECL, gnu_entity_name, gnu_type); + SET_DECL_VALUE_EXPR (gnu_decl, value); + DECL_HAS_VALUE_EXPR_P (gnu_decl) = 1; + gnat_pushdecl (gnu_decl, gnat_entity); + break; + } + + /* If this is a loop variable, its type should be the base type. + This is because the code for processing a loop determines whether + a normal loop end test can be done by comparing the bounds of the + loop against those of the base type, which is presumed to be the + size used for computation. But this is not correct when the size + of the subtype is smaller than the type. */ + if (kind == E_Loop_Parameter) + gnu_type = get_base_type (gnu_type); + + /* Reject non-renamed objects whose type is an unconstrained array or + any object whose type is a dummy type or void. */ + if ((TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE + && No (Renamed_Object (gnat_entity))) + || TYPE_IS_DUMMY_P (gnu_type) + || TREE_CODE (gnu_type) == VOID_TYPE) + { + gcc_assert (type_annotate_only); + if (this_global) + force_global--; + return error_mark_node; + } + + /* If an alignment is specified, use it if valid. Note that exceptions + are objects but don't have an alignment. We must do this before we + validate the size, since the alignment can affect the size. */ + if (kind != E_Exception && Known_Alignment (gnat_entity)) + { + gcc_assert (Present (Alignment (gnat_entity))); + align = validate_alignment (Alignment (gnat_entity), gnat_entity, + TYPE_ALIGN (gnu_type)); + + /* No point in changing the type if there is an address clause + as the final type of the object will be a reference type. */ + if (Present (Address_Clause (gnat_entity))) + align = 0; + else + gnu_type + = maybe_pad_type (gnu_type, NULL_TREE, align, gnat_entity, + false, false, definition, true); + } + + /* If we are defining the object, see if it has a Size and validate it + if so. If we are not defining the object and a Size clause applies, + simply retrieve the value. We don't want to ignore the clause and + it is expected to have been validated already. Then get the new + type, if any. */ + if (definition) + gnu_size = validate_size (Esize (gnat_entity), gnu_type, + gnat_entity, VAR_DECL, false, + Has_Size_Clause (gnat_entity)); + else if (Has_Size_Clause (gnat_entity)) + gnu_size = UI_To_gnu (Esize (gnat_entity), bitsizetype); + + if (gnu_size) + { + gnu_type + = make_type_from_size (gnu_type, gnu_size, + Has_Biased_Representation (gnat_entity)); + + if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0)) + gnu_size = NULL_TREE; + } + + /* If this object has self-referential size, it must be a record with + a default discriminant. We are supposed to allocate an object of + the maximum size in this case, unless it is a constant with an + initializing expression, in which case we can get the size from + that. Note that the resulting size may still be a variable, so + this may end up with an indirect allocation. */ + if (No (Renamed_Object (gnat_entity)) + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))) + { + if (gnu_expr && kind == E_Constant) + { + tree size = TYPE_SIZE (TREE_TYPE (gnu_expr)); + if (CONTAINS_PLACEHOLDER_P (size)) + { + /* If the initializing expression is itself a constant, + despite having a nominal type with self-referential + size, we can get the size directly from it. */ + if (TREE_CODE (gnu_expr) == COMPONENT_REF + && TYPE_IS_PADDING_P + (TREE_TYPE (TREE_OPERAND (gnu_expr, 0))) + && TREE_CODE (TREE_OPERAND (gnu_expr, 0)) == VAR_DECL + && (TREE_READONLY (TREE_OPERAND (gnu_expr, 0)) + || DECL_READONLY_ONCE_ELAB + (TREE_OPERAND (gnu_expr, 0)))) + gnu_size = DECL_SIZE (TREE_OPERAND (gnu_expr, 0)); + else + gnu_size + = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, gnu_expr); + } + else + gnu_size = size; + } + /* We may have no GNU_EXPR because No_Initialization is + set even though there's an Expression. */ + else if (kind == E_Constant + && (Nkind (Declaration_Node (gnat_entity)) + == N_Object_Declaration) + && Present (Expression (Declaration_Node (gnat_entity)))) + gnu_size + = TYPE_SIZE (gnat_to_gnu_type + (Etype + (Expression (Declaration_Node (gnat_entity))))); + else + { + gnu_size = max_size (TYPE_SIZE (gnu_type), true); + mutable_p = true; + } + } + + /* If the size is zero byte, make it one byte since some linkers have + troubles with zero-sized objects. If the object will have a + template, that will make it nonzero so don't bother. Also avoid + doing that for an object renaming or an object with an address + clause, as we would lose useful information on the view size + (e.g. for null array slices) and we are not allocating the object + here anyway. */ + if (((gnu_size + && integer_zerop (gnu_size) + && !TREE_OVERFLOW (gnu_size)) + || (TYPE_SIZE (gnu_type) + && integer_zerop (TYPE_SIZE (gnu_type)) + && !TREE_OVERFLOW (TYPE_SIZE (gnu_type)))) + && (!Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity)) + || !Is_Array_Type (Etype (gnat_entity))) + && No (Renamed_Object (gnat_entity)) + && No (Address_Clause (gnat_entity))) + gnu_size = bitsize_unit_node; + + /* If this is an object with no specified size and alignment, and + if either it is atomic or we are not optimizing alignment for + space and it is composite and not an exception, an Out parameter + or a reference to another object, and the size of its type is a + constant, set the alignment to the smallest one which is not + smaller than the size, with an appropriate cap. */ + if (!gnu_size && align == 0 + && (Is_Atomic (gnat_entity) + || (!Optimize_Alignment_Space (gnat_entity) + && kind != E_Exception + && kind != E_Out_Parameter + && Is_Composite_Type (Etype (gnat_entity)) + && !Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity)) + && !Is_Exported (gnat_entity) + && !imported_p + && No (Renamed_Object (gnat_entity)) + && No (Address_Clause (gnat_entity)))) + && TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST) + { + unsigned int size_cap, align_cap; + + /* No point in promoting the alignment if this doesn't prevent + BLKmode access to the object, in particular block copy, as + this will for example disable the NRV optimization for it. + No point in jumping through all the hoops needed in order + to support BIGGEST_ALIGNMENT if we don't really have to. + So we cap to the smallest alignment that corresponds to + a known efficient memory access pattern of the target. */ + if (Is_Atomic (gnat_entity)) + { + size_cap = UINT_MAX; + align_cap = BIGGEST_ALIGNMENT; + } + else + { + size_cap = MAX_FIXED_MODE_SIZE; + align_cap = get_mode_alignment (ptr_mode); + } + + if (!host_integerp (TYPE_SIZE (gnu_type), 1) + || compare_tree_int (TYPE_SIZE (gnu_type), size_cap) > 0) + align = 0; + else if (compare_tree_int (TYPE_SIZE (gnu_type), align_cap) > 0) + align = align_cap; + else + align = ceil_alignment (tree_low_cst (TYPE_SIZE (gnu_type), 1)); + + /* But make sure not to under-align the object. */ + if (align <= TYPE_ALIGN (gnu_type)) + align = 0; + + /* And honor the minimum valid atomic alignment, if any. */ +#ifdef MINIMUM_ATOMIC_ALIGNMENT + else if (align < MINIMUM_ATOMIC_ALIGNMENT) + align = MINIMUM_ATOMIC_ALIGNMENT; +#endif + } + + /* If the object is set to have atomic components, find the component + type and validate it. + + ??? Note that we ignore Has_Volatile_Components on objects; it's + not at all clear what to do in that case. */ + if (Has_Atomic_Components (gnat_entity)) + { + tree gnu_inner = (TREE_CODE (gnu_type) == ARRAY_TYPE + ? TREE_TYPE (gnu_type) : gnu_type); + + while (TREE_CODE (gnu_inner) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (gnu_inner)) + gnu_inner = TREE_TYPE (gnu_inner); + + check_ok_for_atomic (gnu_inner, gnat_entity, true); + } + + /* Now check if the type of the object allows atomic access. Note + that we must test the type, even if this object has size and + alignment to allow such access, because we will be going inside + the padded record to assign to the object. We could fix this by + always copying via an intermediate value, but it's not clear it's + worth the effort. */ + if (Is_Atomic (gnat_entity)) + check_ok_for_atomic (gnu_type, gnat_entity, false); + + /* If this is an aliased object with an unconstrained nominal subtype, + make a type that includes the template. */ + if (Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity)) + && Is_Array_Type (Etype (gnat_entity)) + && !type_annotate_only) + { + tree gnu_fat + = TREE_TYPE (gnat_to_gnu_type (Base_Type (Etype (gnat_entity)))); + + gnu_type + = build_unc_object_type_from_ptr (gnu_fat, gnu_type, + concat_name (gnu_entity_name, + "UNC"), + debug_info_p); + } + +#ifdef MINIMUM_ATOMIC_ALIGNMENT + /* If the size is a constant and no alignment is specified, force + the alignment to be the minimum valid atomic alignment. The + restriction on constant size avoids problems with variable-size + temporaries; if the size is variable, there's no issue with + atomic access. Also don't do this for a constant, since it isn't + necessary and can interfere with constant replacement. Finally, + do not do it for Out parameters since that creates an + size inconsistency with In parameters. */ + if (align == 0 && MINIMUM_ATOMIC_ALIGNMENT > TYPE_ALIGN (gnu_type) + && !FLOAT_TYPE_P (gnu_type) + && !const_flag && No (Renamed_Object (gnat_entity)) + && !imported_p && No (Address_Clause (gnat_entity)) + && kind != E_Out_Parameter + && (gnu_size ? TREE_CODE (gnu_size) == INTEGER_CST + : TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST)) + align = MINIMUM_ATOMIC_ALIGNMENT; +#endif + + /* Make a new type with the desired size and alignment, if needed. + But do not take into account alignment promotions to compute the + size of the object. */ + gnu_object_size = gnu_size ? gnu_size : TYPE_SIZE (gnu_type); + if (gnu_size || align > 0) + gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity, + false, false, definition, + gnu_size ? true : false); + + /* If this is a renaming, avoid as much as possible to create a new + object. However, in several cases, creating it is required. + This processing needs to be applied to the raw expression so + as to make it more likely to rename the underlying object. */ + if (Present (Renamed_Object (gnat_entity))) + { + bool create_normal_object = false; + + /* If the renamed object had padding, strip off the reference + to the inner object and reset our type. */ + if ((TREE_CODE (gnu_expr) == COMPONENT_REF + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_expr, 0)))) + /* Strip useless conversions around the object. */ + || (TREE_CODE (gnu_expr) == NOP_EXPR + && gnat_types_compatible_p + (TREE_TYPE (gnu_expr), + TREE_TYPE (TREE_OPERAND (gnu_expr, 0))))) + { + gnu_expr = TREE_OPERAND (gnu_expr, 0); + gnu_type = TREE_TYPE (gnu_expr); + } + + /* Case 1: If this is a constant renaming stemming from a function + call, treat it as a normal object whose initial value is what + is being renamed. RM 3.3 says that the result of evaluating a + function call is a constant object. As a consequence, it can + be the inner object of a constant renaming. In this case, the + renaming must be fully instantiated, i.e. it cannot be a mere + reference to (part of) an existing object. */ + if (const_flag) + { + tree inner_object = gnu_expr; + while (handled_component_p (inner_object)) + inner_object = TREE_OPERAND (inner_object, 0); + if (TREE_CODE (inner_object) == CALL_EXPR) + create_normal_object = true; + } + + /* Otherwise, see if we can proceed with a stabilized version of + the renamed entity or if we need to make a new object. */ + if (!create_normal_object) + { + tree maybe_stable_expr = NULL_TREE; + bool stable = false; + + /* Case 2: If the renaming entity need not be materialized and + the renamed expression is something we can stabilize, use + that for the renaming. At the global level, we can only do + this if we know no SAVE_EXPRs need be made, because the + expression we return might be used in arbitrary conditional + branches so we must force the evaluation of the SAVE_EXPRs + immediately and this requires a proper function context. + Note that an external constant is at the global level. */ + if (!Materialize_Entity (gnat_entity) + && (!((!definition && kind == E_Constant) + || global_bindings_p ()) + || (staticp (gnu_expr) + && !TREE_SIDE_EFFECTS (gnu_expr)))) + { + maybe_stable_expr + = gnat_stabilize_reference (gnu_expr, true, &stable); + + if (stable) + { + /* ??? No DECL_EXPR is created so we need to mark + the expression manually lest it is shared. */ + if ((!definition && kind == E_Constant) + || global_bindings_p ()) + MARK_VISITED (maybe_stable_expr); + gnu_decl = maybe_stable_expr; + save_gnu_tree (gnat_entity, gnu_decl, true); + saved = true; + annotate_object (gnat_entity, gnu_type, NULL_TREE, + false, false); + break; + } + + /* The stabilization failed. Keep maybe_stable_expr + untouched here to let the pointer case below know + about that failure. */ + } + + /* Case 3: If this is a constant renaming and creating a + new object is allowed and cheap, treat it as a normal + object whose initial value is what is being renamed. */ + if (const_flag + && !Is_Composite_Type + (Underlying_Type (Etype (gnat_entity)))) + ; + + /* Case 4: Make this into a constant pointer to the object we + are to rename and attach the object to the pointer if it is + something we can stabilize. + + From the proper scope, attached objects will be referenced + directly instead of indirectly via the pointer to avoid + subtle aliasing problems with non-addressable entities. + They have to be stable because we must not evaluate the + variables in the expression every time the renaming is used. + The pointer is called a "renaming" pointer in this case. + + In the rare cases where we cannot stabilize the renamed + object, we just make a "bare" pointer, and the renamed + entity is always accessed indirectly through it. */ + else + { + /* We need to preserve the volatileness of the renamed + object through the indirection. */ + if (TREE_THIS_VOLATILE (gnu_expr) + && !TYPE_VOLATILE (gnu_type)) + gnu_type + = build_qualified_type (gnu_type, + (TYPE_QUALS (gnu_type) + | TYPE_QUAL_VOLATILE)); + gnu_type = build_reference_type (gnu_type); + inner_const_flag = TREE_READONLY (gnu_expr); + const_flag = true; + + /* If the previous attempt at stabilizing failed, there + is no point in trying again and we reuse the result + without attaching it to the pointer. In this case it + will only be used as the initializing expression of + the pointer and thus needs no special treatment with + regard to multiple evaluations. */ + if (maybe_stable_expr) + ; + + /* Otherwise, try to stabilize and attach the expression + to the pointer if the stabilization succeeds. + + Note that this might introduce SAVE_EXPRs and we don't + check whether we're at the global level or not. This + is fine since we are building a pointer initializer and + neither the pointer nor the initializing expression can + be accessed before the pointer elaboration has taken + place in a correct program. + + These SAVE_EXPRs will be evaluated at the right place + by either the evaluation of the initializer for the + non-global case or the elaboration code for the global + case, and will be attached to the elaboration procedure + in the latter case. */ + else + { + maybe_stable_expr + = gnat_stabilize_reference (gnu_expr, true, &stable); + + if (stable) + renamed_obj = maybe_stable_expr; + + /* Attaching is actually performed downstream, as soon + as we have a VAR_DECL for the pointer we make. */ + } + + gnu_expr = build_unary_op (ADDR_EXPR, gnu_type, + maybe_stable_expr); + + gnu_size = NULL_TREE; + used_by_ref = true; + } + } + } + + /* Make a volatile version of this object's type if we are to make + the object volatile. We also interpret 13.3(19) conservatively + and disallow any optimizations for such a non-constant object. */ + if ((Treat_As_Volatile (gnat_entity) + || (!const_flag + && gnu_type != except_type_node + && (Is_Exported (gnat_entity) + || imported_p + || Present (Address_Clause (gnat_entity))))) + && !TYPE_VOLATILE (gnu_type)) + gnu_type = build_qualified_type (gnu_type, + (TYPE_QUALS (gnu_type) + | TYPE_QUAL_VOLATILE)); + + /* If we are defining an aliased object whose nominal subtype is + unconstrained, the object is a record that contains both the + template and the object. If there is an initializer, it will + have already been converted to the right type, but we need to + create the template if there is no initializer. */ + if (definition + && !gnu_expr + && TREE_CODE (gnu_type) == RECORD_TYPE + && (TYPE_CONTAINS_TEMPLATE_P (gnu_type) + /* Beware that padding might have been introduced above. */ + || (TYPE_PADDING_P (gnu_type) + && TREE_CODE (TREE_TYPE (TYPE_FIELDS (gnu_type))) + == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P + (TREE_TYPE (TYPE_FIELDS (gnu_type)))))) + { + tree template_field + = TYPE_PADDING_P (gnu_type) + ? TYPE_FIELDS (TREE_TYPE (TYPE_FIELDS (gnu_type))) + : TYPE_FIELDS (gnu_type); + VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 1); + tree t = build_template (TREE_TYPE (template_field), + TREE_TYPE (DECL_CHAIN (template_field)), + NULL_TREE); + CONSTRUCTOR_APPEND_ELT (v, template_field, t); + gnu_expr = gnat_build_constructor (gnu_type, v); + } + + /* Convert the expression to the type of the object except in the + case where the object's type is unconstrained or the object's type + is a padded record whose field is of self-referential size. In + the former case, converting will generate unnecessary evaluations + of the CONSTRUCTOR to compute the size and in the latter case, we + want to only copy the actual data. */ + if (gnu_expr + && TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)) + && !(TYPE_IS_PADDING_P (gnu_type) + && CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_type)))))) + gnu_expr = convert (gnu_type, gnu_expr); + + /* If this is a pointer that doesn't have an initializing expression, + initialize it to NULL, unless the object is imported. */ + if (definition + && (POINTER_TYPE_P (gnu_type) || TYPE_IS_FAT_POINTER_P (gnu_type)) + && !gnu_expr + && !Is_Imported (gnat_entity)) + gnu_expr = integer_zero_node; + + /* If we are defining the object and it has an Address clause, we must + either get the address expression from the saved GCC tree for the + object if it has a Freeze node, or elaborate the address expression + here since the front-end has guaranteed that the elaboration has no + effects in this case. */ + if (definition && Present (Address_Clause (gnat_entity))) + { + Node_Id gnat_expr = Expression (Address_Clause (gnat_entity)); + tree gnu_address + = present_gnu_tree (gnat_entity) + ? get_gnu_tree (gnat_entity) : gnat_to_gnu (gnat_expr); + + save_gnu_tree (gnat_entity, NULL_TREE, false); + + /* Ignore the size. It's either meaningless or was handled + above. */ + gnu_size = NULL_TREE; + /* Convert the type of the object to a reference type that can + alias everything as per 13.3(19). */ + gnu_type + = build_reference_type_for_mode (gnu_type, ptr_mode, true); + gnu_address = convert (gnu_type, gnu_address); + used_by_ref = true; + const_flag + = !Is_Public (gnat_entity) + || compile_time_known_address_p (gnat_expr); + + /* If this is a deferred constant, the initializer is attached to + the full view. */ + if (kind == E_Constant && Present (Full_View (gnat_entity))) + gnu_expr + = gnat_to_gnu + (Expression (Declaration_Node (Full_View (gnat_entity)))); + + /* If we don't have an initializing expression for the underlying + variable, the initializing expression for the pointer is the + specified address. Otherwise, we have to make a COMPOUND_EXPR + to assign both the address and the initial value. */ + if (!gnu_expr) + gnu_expr = gnu_address; + else + gnu_expr + = build2 (COMPOUND_EXPR, gnu_type, + build_binary_op + (MODIFY_EXPR, NULL_TREE, + build_unary_op (INDIRECT_REF, NULL_TREE, + gnu_address), + gnu_expr), + gnu_address); + } + + /* If it has an address clause and we are not defining it, mark it + as an indirect object. Likewise for Stdcall objects that are + imported. */ + if ((!definition && Present (Address_Clause (gnat_entity))) + || (Is_Imported (gnat_entity) + && Has_Stdcall_Convention (gnat_entity))) + { + /* Convert the type of the object to a reference type that can + alias everything as per 13.3(19). */ + gnu_type + = build_reference_type_for_mode (gnu_type, ptr_mode, true); + gnu_size = NULL_TREE; + + /* No point in taking the address of an initializing expression + that isn't going to be used. */ + gnu_expr = NULL_TREE; + + /* If it has an address clause whose value is known at compile + time, make the object a CONST_DECL. This will avoid a + useless dereference. */ + if (Present (Address_Clause (gnat_entity))) + { + Node_Id gnat_address + = Expression (Address_Clause (gnat_entity)); + + if (compile_time_known_address_p (gnat_address)) + { + gnu_expr = gnat_to_gnu (gnat_address); + const_flag = true; + } + } + + used_by_ref = true; + } + + /* If we are at top level and this object is of variable size, + make the actual type a hidden pointer to the real type and + make the initializer be a memory allocation and initialization. + Likewise for objects we aren't defining (presumed to be + external references from other packages), but there we do + not set up an initialization. + + If the object's size overflows, make an allocator too, so that + Storage_Error gets raised. Note that we will never free + such memory, so we presume it never will get allocated. */ + if (!allocatable_size_p (TYPE_SIZE_UNIT (gnu_type), + global_bindings_p () + || !definition + || static_p) + || (gnu_size && !allocatable_size_p (gnu_size, + global_bindings_p () + || !definition + || static_p))) + { + gnu_type = build_reference_type (gnu_type); + gnu_size = NULL_TREE; + used_by_ref = true; + + /* In case this was a aliased object whose nominal subtype is + unconstrained, the pointer above will be a thin pointer and + build_allocator will automatically make the template. + + If we have a template initializer only (that we made above), + pretend there is none and rely on what build_allocator creates + again anyway. Otherwise (if we have a full initializer), get + the data part and feed that to build_allocator. + + If we are elaborating a mutable object, tell build_allocator to + ignore a possibly simpler size from the initializer, if any, as + we must allocate the maximum possible size in this case. */ + if (definition && !imported_p) + { + tree gnu_alloc_type = TREE_TYPE (gnu_type); + + if (TREE_CODE (gnu_alloc_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_alloc_type)) + { + gnu_alloc_type + = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_alloc_type))); + + if (TREE_CODE (gnu_expr) == CONSTRUCTOR + && 1 == VEC_length (constructor_elt, + CONSTRUCTOR_ELTS (gnu_expr))) + gnu_expr = 0; + else + gnu_expr + = build_component_ref + (gnu_expr, NULL_TREE, + DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (gnu_expr))), + false); + } + + if (TREE_CODE (TYPE_SIZE_UNIT (gnu_alloc_type)) == INTEGER_CST + && TREE_OVERFLOW (TYPE_SIZE_UNIT (gnu_alloc_type))) + post_error ("?`Storage_Error` will be raised at run time!", + gnat_entity); + + gnu_expr + = build_allocator (gnu_alloc_type, gnu_expr, gnu_type, + Empty, Empty, gnat_entity, mutable_p); + const_flag = true; + } + else + { + gnu_expr = NULL_TREE; + const_flag = false; + } + } + + /* If this object would go into the stack and has an alignment larger + than the largest stack alignment the back-end can honor, resort to + a variable of "aligning type". */ + if (!global_bindings_p () && !static_p && definition + && !imported_p && TYPE_ALIGN (gnu_type) > BIGGEST_ALIGNMENT) + { + /* Create the new variable. No need for extra room before the + aligned field as this is in automatic storage. */ + tree gnu_new_type + = make_aligning_type (gnu_type, TYPE_ALIGN (gnu_type), + TYPE_SIZE_UNIT (gnu_type), + BIGGEST_ALIGNMENT, 0); + tree gnu_new_var + = create_var_decl (create_concat_name (gnat_entity, "ALIGN"), + NULL_TREE, gnu_new_type, NULL_TREE, false, + false, false, false, NULL, gnat_entity); + + /* Initialize the aligned field if we have an initializer. */ + if (gnu_expr) + add_stmt_with_node + (build_binary_op (MODIFY_EXPR, NULL_TREE, + build_component_ref + (gnu_new_var, NULL_TREE, + TYPE_FIELDS (gnu_new_type), false), + gnu_expr), + gnat_entity); + + /* And setup this entity as a reference to the aligned field. */ + gnu_type = build_reference_type (gnu_type); + gnu_expr + = build_unary_op + (ADDR_EXPR, gnu_type, + build_component_ref (gnu_new_var, NULL_TREE, + TYPE_FIELDS (gnu_new_type), false)); + + gnu_size = NULL_TREE; + used_by_ref = true; + const_flag = true; + } + + if (const_flag) + gnu_type = build_qualified_type (gnu_type, (TYPE_QUALS (gnu_type) + | TYPE_QUAL_CONST)); + + /* Convert the expression to the type of the object except in the + case where the object's type is unconstrained or the object's type + is a padded record whose field is of self-referential size. In + the former case, converting will generate unnecessary evaluations + of the CONSTRUCTOR to compute the size and in the latter case, we + want to only copy the actual data. */ + if (gnu_expr + && TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)) + && !(TYPE_IS_PADDING_P (gnu_type) + && CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_type)))))) + gnu_expr = convert (gnu_type, gnu_expr); + + /* If this name is external or there was a name specified, use it, + unless this is a VMS exception object since this would conflict + with the symbol we need to export in addition. Don't use the + Interface_Name if there is an address clause (see CD30005). */ + if (!Is_VMS_Exception (gnat_entity) + && ((Present (Interface_Name (gnat_entity)) + && No (Address_Clause (gnat_entity))) + || (Is_Public (gnat_entity) + && (!Is_Imported (gnat_entity) + || Is_Exported (gnat_entity))))) + gnu_ext_name = create_concat_name (gnat_entity, NULL); + + /* If this is an aggregate constant initialized to a constant, force it + to be statically allocated. This saves an initialization copy. */ + if (!static_p + && const_flag + && gnu_expr && TREE_CONSTANT (gnu_expr) + && AGGREGATE_TYPE_P (gnu_type) + && host_integerp (TYPE_SIZE_UNIT (gnu_type), 1) + && !(TYPE_IS_PADDING_P (gnu_type) + && !host_integerp (TYPE_SIZE_UNIT + (TREE_TYPE (TYPE_FIELDS (gnu_type))), 1))) + static_p = true; + + /* Now create the variable or the constant and set various flags. */ + gnu_decl + = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type, + gnu_expr, const_flag, Is_Public (gnat_entity), + imported_p || !definition, static_p, attr_list, + gnat_entity); + DECL_BY_REF_P (gnu_decl) = used_by_ref; + DECL_POINTS_TO_READONLY_P (gnu_decl) = used_by_ref && inner_const_flag; + + /* If we are defining an Out parameter and optimization isn't enabled, + create a fake PARM_DECL for debugging purposes and make it point to + the VAR_DECL. Suppress debug info for the latter but make sure it + will live on the stack so that it can be accessed from within the + debugger through the PARM_DECL. */ + if (kind == E_Out_Parameter && definition && !optimize && debug_info_p) + { + tree param = create_param_decl (gnu_entity_name, gnu_type, false); + gnat_pushdecl (param, gnat_entity); + SET_DECL_VALUE_EXPR (param, gnu_decl); + DECL_HAS_VALUE_EXPR_P (param) = 1; + DECL_IGNORED_P (gnu_decl) = 1; + TREE_ADDRESSABLE (gnu_decl) = 1; + } + + /* If this is a renaming pointer, attach the renamed object to it and + register it if we are at the global level. Note that an external + constant is at the global level. */ + if (TREE_CODE (gnu_decl) == VAR_DECL && renamed_obj) + { + SET_DECL_RENAMED_OBJECT (gnu_decl, renamed_obj); + if ((!definition && kind == E_Constant) || global_bindings_p ()) + { + DECL_RENAMING_GLOBAL_P (gnu_decl) = 1; + record_global_renaming_pointer (gnu_decl); + } + } + + /* If this is a constant and we are defining it or it generates a real + symbol at the object level and we are referencing it, we may want + or need to have a true variable to represent it: + - if optimization isn't enabled, for debugging purposes, + - if the constant is public and not overlaid on something else, + - if its address is taken, + - if either itself or its type is aliased. */ + if (TREE_CODE (gnu_decl) == CONST_DECL + && (definition || Sloc (gnat_entity) > Standard_Location) + && ((!optimize && debug_info_p) + || (Is_Public (gnat_entity) + && No (Address_Clause (gnat_entity))) + || Address_Taken (gnat_entity) + || Is_Aliased (gnat_entity) + || Is_Aliased (Etype (gnat_entity)))) + { + tree gnu_corr_var + = create_true_var_decl (gnu_entity_name, gnu_ext_name, gnu_type, + gnu_expr, true, Is_Public (gnat_entity), + !definition, static_p, attr_list, + gnat_entity); + + SET_DECL_CONST_CORRESPONDING_VAR (gnu_decl, gnu_corr_var); + + /* As debugging information will be generated for the variable, + do not generate debugging information for the constant. */ + if (debug_info_p) + DECL_IGNORED_P (gnu_decl) = 1; + else + DECL_IGNORED_P (gnu_corr_var) = 1; + } + + /* If this is a constant, even if we don't need a true variable, we + may need to avoid returning the initializer in every case. That + can happen for the address of a (constant) constructor because, + upon dereferencing it, the constructor will be reinjected in the + tree, which may not be valid in every case; see lvalue_required_p + for more details. */ + if (TREE_CODE (gnu_decl) == CONST_DECL) + DECL_CONST_ADDRESS_P (gnu_decl) = constructor_address_p (gnu_expr); + + /* If this object is declared in a block that contains a block with an + exception handler, and we aren't using the GCC exception mechanism, + we must force this variable in memory in order to avoid an invalid + optimization. */ + if (Exception_Mechanism != Back_End_Exceptions + && Has_Nested_Block_With_Handler (Scope (gnat_entity))) + TREE_ADDRESSABLE (gnu_decl) = 1; + + /* If we are defining an object with variable size or an object with + fixed size that will be dynamically allocated, and we are using the + setjmp/longjmp exception mechanism, update the setjmp buffer. */ + if (definition + && Exception_Mechanism == Setjmp_Longjmp + && get_block_jmpbuf_decl () + && DECL_SIZE_UNIT (gnu_decl) + && (TREE_CODE (DECL_SIZE_UNIT (gnu_decl)) != INTEGER_CST + || (flag_stack_check == GENERIC_STACK_CHECK + && compare_tree_int (DECL_SIZE_UNIT (gnu_decl), + STACK_CHECK_MAX_VAR_SIZE) > 0))) + add_stmt_with_node (build_call_1_expr + (update_setjmp_buf_decl, + build_unary_op (ADDR_EXPR, NULL_TREE, + get_block_jmpbuf_decl ())), + gnat_entity); + + /* Back-annotate Esize and Alignment of the object if not already + known. Note that we pick the values of the type, not those of + the object, to shield ourselves from low-level platform-dependent + adjustments like alignment promotion. This is both consistent with + all the treatment above, where alignment and size are set on the + type of the object and not on the object directly, and makes it + possible to support all confirming representation clauses. */ + annotate_object (gnat_entity, TREE_TYPE (gnu_decl), gnu_object_size, + used_by_ref, false); + } + break; + + case E_Void: + /* Return a TYPE_DECL for "void" that we previously made. */ + gnu_decl = TYPE_NAME (void_type_node); + break; + + case E_Enumeration_Type: + /* A special case: for the types Character and Wide_Character in + Standard, we do not list all the literals. So if the literals + are not specified, make this an unsigned type. */ + if (No (First_Literal (gnat_entity))) + { + gnu_type = make_unsigned_type (esize); + TYPE_NAME (gnu_type) = gnu_entity_name; + + /* Set TYPE_STRING_FLAG for Character and Wide_Character types. + This is needed by the DWARF-2 back-end to distinguish between + unsigned integer types and character types. */ + TYPE_STRING_FLAG (gnu_type) = 1; + break; + } + + { + /* We have a list of enumeral constants in First_Literal. We make a + CONST_DECL for each one and build into GNU_LITERAL_LIST the list to + be placed into TYPE_FIELDS. Each node in the list is a TREE_LIST + whose TREE_VALUE is the literal name and whose TREE_PURPOSE is the + value of the literal. But when we have a regular boolean type, we + simplify this a little by using a BOOLEAN_TYPE. */ + bool is_boolean = Is_Boolean_Type (gnat_entity) + && !Has_Non_Standard_Rep (gnat_entity); + tree gnu_literal_list = NULL_TREE; + Entity_Id gnat_literal; + + if (Is_Unsigned_Type (gnat_entity)) + gnu_type = make_unsigned_type (esize); + else + gnu_type = make_signed_type (esize); + + TREE_SET_CODE (gnu_type, is_boolean ? BOOLEAN_TYPE : ENUMERAL_TYPE); + + for (gnat_literal = First_Literal (gnat_entity); + Present (gnat_literal); + gnat_literal = Next_Literal (gnat_literal)) + { + tree gnu_value + = UI_To_gnu (Enumeration_Rep (gnat_literal), gnu_type); + tree gnu_literal + = create_var_decl (get_entity_name (gnat_literal), NULL_TREE, + gnu_type, gnu_value, true, false, false, + false, NULL, gnat_literal); + /* Do not generate debug info for individual enumerators. */ + DECL_IGNORED_P (gnu_literal) = 1; + save_gnu_tree (gnat_literal, gnu_literal, false); + gnu_literal_list = tree_cons (DECL_NAME (gnu_literal), + gnu_value, gnu_literal_list); + } + + if (!is_boolean) + TYPE_VALUES (gnu_type) = nreverse (gnu_literal_list); + + /* Note that the bounds are updated at the end of this function + to avoid an infinite recursion since they refer to the type. */ + } + goto discrete_type; + + case E_Signed_Integer_Type: + case E_Ordinary_Fixed_Point_Type: + case E_Decimal_Fixed_Point_Type: + /* For integer types, just make a signed type the appropriate number + of bits. */ + gnu_type = make_signed_type (esize); + goto discrete_type; + + case E_Modular_Integer_Type: + { + /* For modular types, make the unsigned type of the proper number + of bits and then set up the modulus, if required. */ + tree gnu_modulus, gnu_high = NULL_TREE; + + /* Packed array types are supposed to be subtypes only. */ + gcc_assert (!Is_Packed_Array_Type (gnat_entity)); + + gnu_type = make_unsigned_type (esize); + + /* Get the modulus in this type. If it overflows, assume it is because + it is equal to 2**Esize. Note that there is no overflow checking + done on unsigned type, so we detect the overflow by looking for + a modulus of zero, which is otherwise invalid. */ + gnu_modulus = UI_To_gnu (Modulus (gnat_entity), gnu_type); + + if (!integer_zerop (gnu_modulus)) + { + TYPE_MODULAR_P (gnu_type) = 1; + SET_TYPE_MODULUS (gnu_type, gnu_modulus); + gnu_high = fold_build2 (MINUS_EXPR, gnu_type, gnu_modulus, + convert (gnu_type, integer_one_node)); + } + + /* If the upper bound is not maximal, make an extra subtype. */ + if (gnu_high + && !tree_int_cst_equal (gnu_high, TYPE_MAX_VALUE (gnu_type))) + { + tree gnu_subtype = make_unsigned_type (esize); + SET_TYPE_RM_MAX_VALUE (gnu_subtype, gnu_high); + TREE_TYPE (gnu_subtype) = gnu_type; + TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1; + TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "UMT"); + gnu_type = gnu_subtype; + } + } + goto discrete_type; + + case E_Signed_Integer_Subtype: + case E_Enumeration_Subtype: + case E_Modular_Integer_Subtype: + case E_Ordinary_Fixed_Point_Subtype: + case E_Decimal_Fixed_Point_Subtype: + + /* For integral subtypes, we make a new INTEGER_TYPE. Note that we do + not want to call create_range_type since we would like each subtype + node to be distinct. ??? Historically this was in preparation for + when memory aliasing is implemented, but that's obsolete now given + the call to relate_alias_sets below. + + The TREE_TYPE field of the INTEGER_TYPE points to the base type; + this fact is used by the arithmetic conversion functions. + + We elaborate the Ancestor_Subtype if it is not in the current unit + and one of our bounds is non-static. We do this to ensure consistent + naming in the case where several subtypes share the same bounds, by + elaborating the first such subtype first, thus using its name. */ + + if (!definition + && Present (Ancestor_Subtype (gnat_entity)) + && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity)) + && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity)) + || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity)))) + gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity), gnu_expr, 0); + + /* Set the precision to the Esize except for bit-packed arrays. */ + if (Is_Packed_Array_Type (gnat_entity) + && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))) + esize = UI_To_Int (RM_Size (gnat_entity)); + + /* This should be an unsigned type if the base type is unsigned or + if the lower bound is constant and non-negative or if the type + is biased. */ + if (Is_Unsigned_Type (Etype (gnat_entity)) + || Is_Unsigned_Type (gnat_entity) + || Has_Biased_Representation (gnat_entity)) + gnu_type = make_unsigned_type (esize); + else + gnu_type = make_signed_type (esize); + TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity)); + + SET_TYPE_RM_MIN_VALUE + (gnu_type, + convert (TREE_TYPE (gnu_type), + elaborate_expression (Type_Low_Bound (gnat_entity), + gnat_entity, get_identifier ("L"), + definition, true, + Needs_Debug_Info (gnat_entity)))); + + SET_TYPE_RM_MAX_VALUE + (gnu_type, + convert (TREE_TYPE (gnu_type), + elaborate_expression (Type_High_Bound (gnat_entity), + gnat_entity, get_identifier ("U"), + definition, true, + Needs_Debug_Info (gnat_entity)))); + + /* One of the above calls might have caused us to be elaborated, + so don't blow up if so. */ + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + + TYPE_BIASED_REPRESENTATION_P (gnu_type) + = Has_Biased_Representation (gnat_entity); + + /* Attach the TYPE_STUB_DECL in case we have a parallel type. */ + TYPE_STUB_DECL (gnu_type) + = create_type_stub_decl (gnu_entity_name, gnu_type); + + /* Inherit our alias set from what we're a subtype of. Subtypes + are not different types and a pointer can designate any instance + within a subtype hierarchy. */ + relate_alias_sets (gnu_type, TREE_TYPE (gnu_type), ALIAS_SET_COPY); + + /* For a packed array, make the original array type a parallel type. */ + if (debug_info_p + && Is_Packed_Array_Type (gnat_entity) + && present_gnu_tree (Original_Array_Type (gnat_entity))) + add_parallel_type (TYPE_STUB_DECL (gnu_type), + gnat_to_gnu_type + (Original_Array_Type (gnat_entity))); + + discrete_type: + + /* We have to handle clauses that under-align the type specially. */ + if ((Present (Alignment_Clause (gnat_entity)) + || (Is_Packed_Array_Type (gnat_entity) + && Present + (Alignment_Clause (Original_Array_Type (gnat_entity))))) + && UI_Is_In_Int_Range (Alignment (gnat_entity))) + { + align = UI_To_Int (Alignment (gnat_entity)) * BITS_PER_UNIT; + if (align >= TYPE_ALIGN (gnu_type)) + align = 0; + } + + /* If the type we are dealing with represents a bit-packed array, + we need to have the bits left justified on big-endian targets + and right justified on little-endian targets. We also need to + ensure that when the value is read (e.g. for comparison of two + such values), we only get the good bits, since the unused bits + are uninitialized. Both goals are accomplished by wrapping up + the modular type in an enclosing record type. */ + if (Is_Packed_Array_Type (gnat_entity) + && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))) + { + tree gnu_field_type, gnu_field; + + /* Set the RM size before wrapping up the original type. */ + SET_TYPE_RM_SIZE (gnu_type, + UI_To_gnu (RM_Size (gnat_entity), bitsizetype)); + TYPE_PACKED_ARRAY_TYPE_P (gnu_type) = 1; + + /* Create a stripped-down declaration, mainly for debugging. */ + create_type_decl (gnu_entity_name, gnu_type, NULL, true, + debug_info_p, gnat_entity); + + /* Now save it and build the enclosing record type. */ + gnu_field_type = gnu_type; + + gnu_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "JM"); + TYPE_PACKED (gnu_type) = 1; + TYPE_SIZE (gnu_type) = TYPE_SIZE (gnu_field_type); + TYPE_SIZE_UNIT (gnu_type) = TYPE_SIZE_UNIT (gnu_field_type); + SET_TYPE_ADA_SIZE (gnu_type, TYPE_RM_SIZE (gnu_field_type)); + + /* Propagate the alignment of the modular type to the record type, + unless there is an alignment clause that under-aligns the type. + This means that bit-packed arrays are given "ceil" alignment for + their size by default, which may seem counter-intuitive but makes + it possible to overlay them on modular types easily. */ + TYPE_ALIGN (gnu_type) + = align > 0 ? align : TYPE_ALIGN (gnu_field_type); + + relate_alias_sets (gnu_type, gnu_field_type, ALIAS_SET_COPY); + + /* Don't declare the field as addressable since we won't be taking + its address and this would prevent create_field_decl from making + a bitfield. */ + gnu_field + = create_field_decl (get_identifier ("OBJECT"), gnu_field_type, + gnu_type, NULL_TREE, bitsize_zero_node, 1, 0); + + /* Do not emit debug info until after the parallel type is added. */ + finish_record_type (gnu_type, gnu_field, 2, false); + compute_record_mode (gnu_type); + TYPE_JUSTIFIED_MODULAR_P (gnu_type) = 1; + + if (debug_info_p) + { + /* Make the original array type a parallel type. */ + if (present_gnu_tree (Original_Array_Type (gnat_entity))) + add_parallel_type (TYPE_STUB_DECL (gnu_type), + gnat_to_gnu_type + (Original_Array_Type (gnat_entity))); + + rest_of_record_type_compilation (gnu_type); + } + } + + /* If the type we are dealing with has got a smaller alignment than the + natural one, we need to wrap it up in a record type and under-align + the latter. We reuse the padding machinery for this purpose. */ + else if (align > 0) + { + tree gnu_field_type, gnu_field; + + /* Set the RM size before wrapping up the type. */ + SET_TYPE_RM_SIZE (gnu_type, + UI_To_gnu (RM_Size (gnat_entity), bitsizetype)); + + /* Create a stripped-down declaration, mainly for debugging. */ + create_type_decl (gnu_entity_name, gnu_type, NULL, true, + debug_info_p, gnat_entity); + + /* Now save it and build the enclosing record type. */ + gnu_field_type = gnu_type; + + gnu_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "PAD"); + TYPE_PACKED (gnu_type) = 1; + TYPE_SIZE (gnu_type) = TYPE_SIZE (gnu_field_type); + TYPE_SIZE_UNIT (gnu_type) = TYPE_SIZE_UNIT (gnu_field_type); + SET_TYPE_ADA_SIZE (gnu_type, TYPE_RM_SIZE (gnu_field_type)); + TYPE_ALIGN (gnu_type) = align; + relate_alias_sets (gnu_type, gnu_field_type, ALIAS_SET_COPY); + + /* Don't declare the field as addressable since we won't be taking + its address and this would prevent create_field_decl from making + a bitfield. */ + gnu_field + = create_field_decl (get_identifier ("F"), gnu_field_type, + gnu_type, NULL_TREE, bitsize_zero_node, 1, 0); + + finish_record_type (gnu_type, gnu_field, 2, debug_info_p); + compute_record_mode (gnu_type); + TYPE_PADDING_P (gnu_type) = 1; + } + + break; + + case E_Floating_Point_Type: + /* If this is a VAX floating-point type, use an integer of the proper + size. All the operations will be handled with ASM statements. */ + if (Vax_Float (gnat_entity)) + { + gnu_type = make_signed_type (esize); + TYPE_VAX_FLOATING_POINT_P (gnu_type) = 1; + SET_TYPE_DIGITS_VALUE (gnu_type, + UI_To_gnu (Digits_Value (gnat_entity), + sizetype)); + break; + } + + /* The type of the Low and High bounds can be our type if this is + a type from Standard, so set them at the end of the function. */ + gnu_type = make_node (REAL_TYPE); + TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize); + layout_type (gnu_type); + break; + + case E_Floating_Point_Subtype: + if (Vax_Float (gnat_entity)) + { + gnu_type = gnat_to_gnu_type (Etype (gnat_entity)); + break; + } + + { + if (!definition + && Present (Ancestor_Subtype (gnat_entity)) + && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity)) + && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity)) + || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity)))) + gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity), + gnu_expr, 0); + + gnu_type = make_node (REAL_TYPE); + TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity)); + TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize); + TYPE_GCC_MIN_VALUE (gnu_type) + = TYPE_GCC_MIN_VALUE (TREE_TYPE (gnu_type)); + TYPE_GCC_MAX_VALUE (gnu_type) + = TYPE_GCC_MAX_VALUE (TREE_TYPE (gnu_type)); + layout_type (gnu_type); + + SET_TYPE_RM_MIN_VALUE + (gnu_type, + convert (TREE_TYPE (gnu_type), + elaborate_expression (Type_Low_Bound (gnat_entity), + gnat_entity, get_identifier ("L"), + definition, true, + Needs_Debug_Info (gnat_entity)))); + + SET_TYPE_RM_MAX_VALUE + (gnu_type, + convert (TREE_TYPE (gnu_type), + elaborate_expression (Type_High_Bound (gnat_entity), + gnat_entity, get_identifier ("U"), + definition, true, + Needs_Debug_Info (gnat_entity)))); + + /* One of the above calls might have caused us to be elaborated, + so don't blow up if so. */ + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + + /* Inherit our alias set from what we're a subtype of, as for + integer subtypes. */ + relate_alias_sets (gnu_type, TREE_TYPE (gnu_type), ALIAS_SET_COPY); + } + break; + + /* Array and String Types and Subtypes + + Unconstrained array types are represented by E_Array_Type and + constrained array types are represented by E_Array_Subtype. There + are no actual objects of an unconstrained array type; all we have + are pointers to that type. + + The following fields are defined on array types and subtypes: + + Component_Type Component type of the array. + Number_Dimensions Number of dimensions (an int). + First_Index Type of first index. */ + + case E_String_Type: + case E_Array_Type: + { + Entity_Id gnat_index, gnat_name; + const bool convention_fortran_p + = (Convention (gnat_entity) == Convention_Fortran); + const int ndim = Number_Dimensions (gnat_entity); + tree gnu_template_fields = NULL_TREE; + tree gnu_template_type = make_node (RECORD_TYPE); + tree gnu_template_reference; + tree gnu_ptr_template = build_pointer_type (gnu_template_type); + tree gnu_fat_type = make_node (RECORD_TYPE); + tree *gnu_index_types = XALLOCAVEC (tree, ndim); + tree *gnu_temp_fields = XALLOCAVEC (tree, ndim); + tree gnu_max_size = size_one_node, gnu_max_size_unit, tem; + int index; + + TYPE_NAME (gnu_template_type) + = create_concat_name (gnat_entity, "XUB"); + + /* Make a node for the array. If we are not defining the array + suppress expanding incomplete types. */ + gnu_type = make_node (UNCONSTRAINED_ARRAY_TYPE); + + if (!definition) + { + defer_incomplete_level++; + this_deferred = true; + } + + /* Build the fat pointer type. Use a "void *" object instead of + a pointer to the array type since we don't have the array type + yet (it will reference the fat pointer via the bounds). */ + tem + = create_field_decl (get_identifier ("P_ARRAY"), ptr_void_type_node, + gnu_fat_type, NULL_TREE, NULL_TREE, 0, 0); + TREE_CHAIN (tem) + = create_field_decl (get_identifier ("P_BOUNDS"), gnu_ptr_template, + gnu_fat_type, NULL_TREE, NULL_TREE, 0, 0); + finish_fat_pointer_type (gnu_fat_type, tem); + + /* Build a reference to the template from a PLACEHOLDER_EXPR that + is the fat pointer. This will be used to access the individual + fields once we build them. */ + tem = build3 (COMPONENT_REF, gnu_ptr_template, + build0 (PLACEHOLDER_EXPR, gnu_fat_type), + DECL_CHAIN (TYPE_FIELDS (gnu_fat_type)), NULL_TREE); + gnu_template_reference + = build_unary_op (INDIRECT_REF, gnu_template_type, tem); + TREE_READONLY (gnu_template_reference) = 1; + + /* Now create the GCC type for each index and add the fields for that + index to the template. */ + for (index = (convention_fortran_p ? ndim - 1 : 0), + gnat_index = First_Index (gnat_entity); + 0 <= index && index < ndim; + index += (convention_fortran_p ? - 1 : 1), + gnat_index = Next_Index (gnat_index)) + { + char field_name[16]; + tree gnu_index_base_type + = get_unpadded_type (Base_Type (Etype (gnat_index))); + tree gnu_lb_field, gnu_hb_field, gnu_orig_min, gnu_orig_max; + tree gnu_min, gnu_max, gnu_high; + + /* Make the FIELD_DECLs for the low and high bounds of this + type and then make extractions of these fields from the + template. */ + sprintf (field_name, "LB%d", index); + gnu_lb_field = create_field_decl (get_identifier (field_name), + gnu_index_base_type, + gnu_template_type, NULL_TREE, + NULL_TREE, 0, 0); + Sloc_to_locus (Sloc (gnat_entity), + &DECL_SOURCE_LOCATION (gnu_lb_field)); + + field_name[0] = 'U'; + gnu_hb_field = create_field_decl (get_identifier (field_name), + gnu_index_base_type, + gnu_template_type, NULL_TREE, + NULL_TREE, 0, 0); + Sloc_to_locus (Sloc (gnat_entity), + &DECL_SOURCE_LOCATION (gnu_hb_field)); + + gnu_temp_fields[index] = chainon (gnu_lb_field, gnu_hb_field); + + /* We can't use build_component_ref here since the template type + isn't complete yet. */ + gnu_orig_min = build3 (COMPONENT_REF, gnu_index_base_type, + gnu_template_reference, gnu_lb_field, + NULL_TREE); + gnu_orig_max = build3 (COMPONENT_REF, gnu_index_base_type, + gnu_template_reference, gnu_hb_field, + NULL_TREE); + TREE_READONLY (gnu_orig_min) = TREE_READONLY (gnu_orig_max) = 1; + + gnu_min = convert (sizetype, gnu_orig_min); + gnu_max = convert (sizetype, gnu_orig_max); + + /* Compute the size of this dimension. See the E_Array_Subtype + case below for the rationale. */ + gnu_high + = build3 (COND_EXPR, sizetype, + build2 (GE_EXPR, boolean_type_node, + gnu_orig_max, gnu_orig_min), + gnu_max, + size_binop (MINUS_EXPR, gnu_min, size_one_node)); + + /* Make a range type with the new range in the Ada base type. + Then make an index type with the size range in sizetype. */ + gnu_index_types[index] + = create_index_type (gnu_min, gnu_high, + create_range_type (gnu_index_base_type, + gnu_orig_min, + gnu_orig_max), + gnat_entity); + + /* Update the maximum size of the array in elements. */ + if (gnu_max_size) + { + tree gnu_index_type = get_unpadded_type (Etype (gnat_index)); + tree gnu_min + = convert (sizetype, TYPE_MIN_VALUE (gnu_index_type)); + tree gnu_max + = convert (sizetype, TYPE_MAX_VALUE (gnu_index_type)); + tree gnu_this_max + = size_binop (MAX_EXPR, + size_binop (PLUS_EXPR, size_one_node, + size_binop (MINUS_EXPR, + gnu_max, gnu_min)), + size_zero_node); + + if (TREE_CODE (gnu_this_max) == INTEGER_CST + && TREE_OVERFLOW (gnu_this_max)) + gnu_max_size = NULL_TREE; + else + gnu_max_size + = size_binop (MULT_EXPR, gnu_max_size, gnu_this_max); + } + + TYPE_NAME (gnu_index_types[index]) + = create_concat_name (gnat_entity, field_name); + } + + for (index = 0; index < ndim; index++) + gnu_template_fields + = chainon (gnu_template_fields, gnu_temp_fields[index]); + + /* Install all the fields into the template. */ + finish_record_type (gnu_template_type, gnu_template_fields, 0, + debug_info_p); + TYPE_READONLY (gnu_template_type) = 1; + + /* Now make the array of arrays and update the pointer to the array + in the fat pointer. Note that it is the first field. */ + tem = gnat_to_gnu_component_type (gnat_entity, definition, + debug_info_p); + + /* If Component_Size is not already specified, annotate it with the + size of the component. */ + if (Unknown_Component_Size (gnat_entity)) + Set_Component_Size (gnat_entity, annotate_value (TYPE_SIZE (tem))); + + /* Compute the maximum size of the array in units and bits. */ + if (gnu_max_size) + { + gnu_max_size_unit = size_binop (MULT_EXPR, gnu_max_size, + TYPE_SIZE_UNIT (tem)); + gnu_max_size = size_binop (MULT_EXPR, + convert (bitsizetype, gnu_max_size), + TYPE_SIZE (tem)); + } + else + gnu_max_size_unit = NULL_TREE; + + /* Now build the array type. */ + for (index = ndim - 1; index >= 0; index--) + { + tem = build_nonshared_array_type (tem, gnu_index_types[index]); + TYPE_MULTI_ARRAY_P (tem) = (index > 0); + if (array_type_has_nonaliased_component (tem, gnat_entity)) + TYPE_NONALIASED_COMPONENT (tem) = 1; + } + + /* If an alignment is specified, use it if valid. But ignore it + for the original type of packed array types. If the alignment + was requested with an explicit alignment clause, state so. */ + if (No (Packed_Array_Type (gnat_entity)) + && Known_Alignment (gnat_entity)) + { + TYPE_ALIGN (tem) + = validate_alignment (Alignment (gnat_entity), gnat_entity, + TYPE_ALIGN (tem)); + if (Present (Alignment_Clause (gnat_entity))) + TYPE_USER_ALIGN (tem) = 1; + } + + TYPE_CONVENTION_FORTRAN_P (tem) = convention_fortran_p; + TREE_TYPE (TYPE_FIELDS (gnu_fat_type)) = build_pointer_type (tem); + + /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the + corresponding fat pointer. */ + TREE_TYPE (gnu_type) = TYPE_POINTER_TO (gnu_type) + = TYPE_REFERENCE_TO (gnu_type) = gnu_fat_type; + SET_TYPE_MODE (gnu_type, BLKmode); + TYPE_ALIGN (gnu_type) = TYPE_ALIGN (tem); + SET_TYPE_UNCONSTRAINED_ARRAY (gnu_fat_type, gnu_type); + + /* If the maximum size doesn't overflow, use it. */ + if (gnu_max_size + && TREE_CODE (gnu_max_size) == INTEGER_CST + && !TREE_OVERFLOW (gnu_max_size) + && TREE_CODE (gnu_max_size_unit) == INTEGER_CST + && !TREE_OVERFLOW (gnu_max_size_unit)) + { + TYPE_SIZE (tem) = size_binop (MIN_EXPR, gnu_max_size, + TYPE_SIZE (tem)); + TYPE_SIZE_UNIT (tem) = size_binop (MIN_EXPR, gnu_max_size_unit, + TYPE_SIZE_UNIT (tem)); + } + + create_type_decl (create_concat_name (gnat_entity, "XUA"), + tem, NULL, !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + + /* Give the fat pointer type a name. If this is a packed type, tell + the debugger how to interpret the underlying bits. */ + if (Present (Packed_Array_Type (gnat_entity))) + gnat_name = Packed_Array_Type (gnat_entity); + else + gnat_name = gnat_entity; + create_type_decl (create_concat_name (gnat_name, "XUP"), + gnu_fat_type, NULL, true, + debug_info_p, gnat_entity); + + /* Create the type to be used as what a thin pointer designates: + a record type for the object and its template with the fields + shifted to have the template at a negative offset. */ + tem = build_unc_object_type (gnu_template_type, tem, + create_concat_name (gnat_name, "XUT"), + debug_info_p); + shift_unc_components_for_thin_pointers (tem); + + SET_TYPE_UNCONSTRAINED_ARRAY (tem, gnu_type); + TYPE_OBJECT_RECORD_TYPE (gnu_type) = tem; + } + break; + + case E_String_Subtype: + case E_Array_Subtype: + + /* This is the actual data type for array variables. Multidimensional + arrays are implemented as arrays of arrays. Note that arrays which + have sparse enumeration subtypes as index components create sparse + arrays, which is obviously space inefficient but so much easier to + code for now. + + Also note that the subtype never refers to the unconstrained array + type, which is somewhat at variance with Ada semantics. + + First check to see if this is simply a renaming of the array type. + If so, the result is the array type. */ + + gnu_type = gnat_to_gnu_type (Etype (gnat_entity)); + if (!Is_Constrained (gnat_entity)) + ; + else + { + Entity_Id gnat_index, gnat_base_index; + const bool convention_fortran_p + = (Convention (gnat_entity) == Convention_Fortran); + const int ndim = Number_Dimensions (gnat_entity); + tree gnu_base_type = gnu_type; + tree *gnu_index_types = XALLOCAVEC (tree, ndim); + tree gnu_max_size = size_one_node, gnu_max_size_unit; + bool need_index_type_struct = false; + int index; + + /* First create the GCC type for each index and find out whether + special types are needed for debugging information. */ + for (index = (convention_fortran_p ? ndim - 1 : 0), + gnat_index = First_Index (gnat_entity), + gnat_base_index + = First_Index (Implementation_Base_Type (gnat_entity)); + 0 <= index && index < ndim; + index += (convention_fortran_p ? - 1 : 1), + gnat_index = Next_Index (gnat_index), + gnat_base_index = Next_Index (gnat_base_index)) + { + tree gnu_index_type = get_unpadded_type (Etype (gnat_index)); + tree gnu_orig_min = TYPE_MIN_VALUE (gnu_index_type); + tree gnu_orig_max = TYPE_MAX_VALUE (gnu_index_type); + tree gnu_min = convert (sizetype, gnu_orig_min); + tree gnu_max = convert (sizetype, gnu_orig_max); + tree gnu_base_index_type + = get_unpadded_type (Etype (gnat_base_index)); + tree gnu_base_orig_min = TYPE_MIN_VALUE (gnu_base_index_type); + tree gnu_base_orig_max = TYPE_MAX_VALUE (gnu_base_index_type); + tree gnu_high; + + /* See if the base array type is already flat. If it is, we + are probably compiling an ACATS test but it will cause the + code below to malfunction if we don't handle it specially. */ + if (TREE_CODE (gnu_base_orig_min) == INTEGER_CST + && TREE_CODE (gnu_base_orig_max) == INTEGER_CST + && tree_int_cst_lt (gnu_base_orig_max, gnu_base_orig_min)) + { + gnu_min = size_one_node; + gnu_max = size_zero_node; + gnu_high = gnu_max; + } + + /* Similarly, if one of the values overflows in sizetype and the + range is null, use 1..0 for the sizetype bounds. */ + else if (TREE_CODE (gnu_min) == INTEGER_CST + && TREE_CODE (gnu_max) == INTEGER_CST + && (TREE_OVERFLOW (gnu_min) || TREE_OVERFLOW (gnu_max)) + && tree_int_cst_lt (gnu_orig_max, gnu_orig_min)) + { + gnu_min = size_one_node; + gnu_max = size_zero_node; + gnu_high = gnu_max; + } + + /* If the minimum and maximum values both overflow in sizetype, + but the difference in the original type does not overflow in + sizetype, ignore the overflow indication. */ + else if (TREE_CODE (gnu_min) == INTEGER_CST + && TREE_CODE (gnu_max) == INTEGER_CST + && TREE_OVERFLOW (gnu_min) && TREE_OVERFLOW (gnu_max) + && !TREE_OVERFLOW + (convert (sizetype, + fold_build2 (MINUS_EXPR, gnu_index_type, + gnu_orig_max, + gnu_orig_min)))) + { + TREE_OVERFLOW (gnu_min) = 0; + TREE_OVERFLOW (gnu_max) = 0; + gnu_high = gnu_max; + } + + /* Compute the size of this dimension in the general case. We + need to provide GCC with an upper bound to use but have to + deal with the "superflat" case. There are three ways to do + this. If we can prove that the array can never be superflat, + we can just use the high bound of the index type. */ + else if ((Nkind (gnat_index) == N_Range + && cannot_be_superflat_p (gnat_index)) + /* Packed Array Types are never superflat. */ + || Is_Packed_Array_Type (gnat_entity)) + gnu_high = gnu_max; + + /* Otherwise, if the high bound is constant but the low bound is + not, we use the expression (hb >= lb) ? lb : hb + 1 for the + lower bound. Note that the comparison must be done in the + original type to avoid any overflow during the conversion. */ + else if (TREE_CODE (gnu_max) == INTEGER_CST + && TREE_CODE (gnu_min) != INTEGER_CST) + { + gnu_high = gnu_max; + gnu_min + = build_cond_expr (sizetype, + build_binary_op (GE_EXPR, + boolean_type_node, + gnu_orig_max, + gnu_orig_min), + gnu_min, + size_binop (PLUS_EXPR, gnu_max, + size_one_node)); + } + + /* Finally we use (hb >= lb) ? hb : lb - 1 for the upper bound + in all the other cases. Note that, here as well as above, + the condition used in the comparison must be equivalent to + the condition (length != 0). This is relied upon in order + to optimize array comparisons in compare_arrays. */ + else + gnu_high + = build_cond_expr (sizetype, + build_binary_op (GE_EXPR, + boolean_type_node, + gnu_orig_max, + gnu_orig_min), + gnu_max, + size_binop (MINUS_EXPR, gnu_min, + size_one_node)); + + /* Reuse the index type for the range type. Then make an index + type with the size range in sizetype. */ + gnu_index_types[index] + = create_index_type (gnu_min, gnu_high, gnu_index_type, + gnat_entity); + + /* Update the maximum size of the array in elements. Here we + see if any constraint on the index type of the base type + can be used in the case of self-referential bound on the + index type of the subtype. We look for a non-"infinite" + and non-self-referential bound from any type involved and + handle each bound separately. */ + if (gnu_max_size) + { + tree gnu_base_min = convert (sizetype, gnu_base_orig_min); + tree gnu_base_max = convert (sizetype, gnu_base_orig_max); + tree gnu_base_index_base_type + = get_base_type (gnu_base_index_type); + tree gnu_base_base_min + = convert (sizetype, + TYPE_MIN_VALUE (gnu_base_index_base_type)); + tree gnu_base_base_max + = convert (sizetype, + TYPE_MAX_VALUE (gnu_base_index_base_type)); + + if (!CONTAINS_PLACEHOLDER_P (gnu_min) + || !(TREE_CODE (gnu_base_min) == INTEGER_CST + && !TREE_OVERFLOW (gnu_base_min))) + gnu_base_min = gnu_min; + + if (!CONTAINS_PLACEHOLDER_P (gnu_max) + || !(TREE_CODE (gnu_base_max) == INTEGER_CST + && !TREE_OVERFLOW (gnu_base_max))) + gnu_base_max = gnu_max; + + if ((TREE_CODE (gnu_base_min) == INTEGER_CST + && TREE_OVERFLOW (gnu_base_min)) + || operand_equal_p (gnu_base_min, gnu_base_base_min, 0) + || (TREE_CODE (gnu_base_max) == INTEGER_CST + && TREE_OVERFLOW (gnu_base_max)) + || operand_equal_p (gnu_base_max, gnu_base_base_max, 0)) + gnu_max_size = NULL_TREE; + else + { + tree gnu_this_max + = size_binop (MAX_EXPR, + size_binop (PLUS_EXPR, size_one_node, + size_binop (MINUS_EXPR, + gnu_base_max, + gnu_base_min)), + size_zero_node); + + if (TREE_CODE (gnu_this_max) == INTEGER_CST + && TREE_OVERFLOW (gnu_this_max)) + gnu_max_size = NULL_TREE; + else + gnu_max_size + = size_binop (MULT_EXPR, gnu_max_size, gnu_this_max); + } + } + + /* We need special types for debugging information to point to + the index types if they have variable bounds, are not integer + types, are biased or are wider than sizetype. */ + if (!integer_onep (gnu_orig_min) + || TREE_CODE (gnu_orig_max) != INTEGER_CST + || TREE_CODE (gnu_index_type) != INTEGER_TYPE + || (TREE_TYPE (gnu_index_type) + && TREE_CODE (TREE_TYPE (gnu_index_type)) + != INTEGER_TYPE) + || TYPE_BIASED_REPRESENTATION_P (gnu_index_type) + || compare_tree_int (rm_size (gnu_index_type), + TYPE_PRECISION (sizetype)) > 0) + need_index_type_struct = true; + } + + /* Then flatten: create the array of arrays. For an array type + used to implement a packed array, get the component type from + the original array type since the representation clauses that + can affect it are on the latter. */ + if (Is_Packed_Array_Type (gnat_entity) + && !Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))) + { + gnu_type = gnat_to_gnu_type (Original_Array_Type (gnat_entity)); + for (index = ndim - 1; index >= 0; index--) + gnu_type = TREE_TYPE (gnu_type); + + /* One of the above calls might have caused us to be elaborated, + so don't blow up if so. */ + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + } + else + { + gnu_type = gnat_to_gnu_component_type (gnat_entity, definition, + debug_info_p); + + /* One of the above calls might have caused us to be elaborated, + so don't blow up if so. */ + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + } + + /* Compute the maximum size of the array in units and bits. */ + if (gnu_max_size) + { + gnu_max_size_unit = size_binop (MULT_EXPR, gnu_max_size, + TYPE_SIZE_UNIT (gnu_type)); + gnu_max_size = size_binop (MULT_EXPR, + convert (bitsizetype, gnu_max_size), + TYPE_SIZE (gnu_type)); + } + else + gnu_max_size_unit = NULL_TREE; + + /* Now build the array type. */ + for (index = ndim - 1; index >= 0; index --) + { + gnu_type = build_nonshared_array_type (gnu_type, + gnu_index_types[index]); + TYPE_MULTI_ARRAY_P (gnu_type) = (index > 0); + if (array_type_has_nonaliased_component (gnu_type, gnat_entity)) + TYPE_NONALIASED_COMPONENT (gnu_type) = 1; + } + + /* Attach the TYPE_STUB_DECL in case we have a parallel type. */ + TYPE_STUB_DECL (gnu_type) + = create_type_stub_decl (gnu_entity_name, gnu_type); + + /* If we are at file level and this is a multi-dimensional array, + we need to make a variable corresponding to the stride of the + inner dimensions. */ + if (global_bindings_p () && ndim > 1) + { + tree gnu_st_name = get_identifier ("ST"); + tree gnu_arr_type; + + for (gnu_arr_type = TREE_TYPE (gnu_type); + TREE_CODE (gnu_arr_type) == ARRAY_TYPE; + gnu_arr_type = TREE_TYPE (gnu_arr_type), + gnu_st_name = concat_name (gnu_st_name, "ST")) + { + tree eltype = TREE_TYPE (gnu_arr_type); + + TYPE_SIZE (gnu_arr_type) + = elaborate_expression_1 (TYPE_SIZE (gnu_arr_type), + gnat_entity, gnu_st_name, + definition, false); + + /* ??? For now, store the size as a multiple of the + alignment of the element type in bytes so that we + can see the alignment from the tree. */ + TYPE_SIZE_UNIT (gnu_arr_type) + = elaborate_expression_2 (TYPE_SIZE_UNIT (gnu_arr_type), + gnat_entity, + concat_name (gnu_st_name, "A_U"), + definition, false, + TYPE_ALIGN (eltype)); + + /* ??? create_type_decl is not invoked on the inner types so + the MULT_EXPR node built above will never be marked. */ + MARK_VISITED (TYPE_SIZE_UNIT (gnu_arr_type)); + } + } + + /* If we need to write out a record type giving the names of the + bounds for debugging purposes, do it now and make the record + type a parallel type. This is not needed for a packed array + since the bounds are conveyed by the original array type. */ + if (need_index_type_struct + && debug_info_p + && !Is_Packed_Array_Type (gnat_entity)) + { + tree gnu_bound_rec = make_node (RECORD_TYPE); + tree gnu_field_list = NULL_TREE; + tree gnu_field; + + TYPE_NAME (gnu_bound_rec) + = create_concat_name (gnat_entity, "XA"); + + for (index = ndim - 1; index >= 0; index--) + { + tree gnu_index = TYPE_INDEX_TYPE (gnu_index_types[index]); + tree gnu_index_name = TYPE_NAME (gnu_index); + + if (TREE_CODE (gnu_index_name) == TYPE_DECL) + gnu_index_name = DECL_NAME (gnu_index_name); + + /* Make sure to reference the types themselves, and not just + their names, as the debugger may fall back on them. */ + gnu_field = create_field_decl (gnu_index_name, gnu_index, + gnu_bound_rec, NULL_TREE, + NULL_TREE, 0, 0); + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + } + + finish_record_type (gnu_bound_rec, gnu_field_list, 0, true); + add_parallel_type (TYPE_STUB_DECL (gnu_type), gnu_bound_rec); + } + + /* Otherwise, for a packed array, make the original array type a + parallel type. */ + else if (debug_info_p + && Is_Packed_Array_Type (gnat_entity) + && present_gnu_tree (Original_Array_Type (gnat_entity))) + add_parallel_type (TYPE_STUB_DECL (gnu_type), + gnat_to_gnu_type + (Original_Array_Type (gnat_entity))); + + TYPE_CONVENTION_FORTRAN_P (gnu_type) = convention_fortran_p; + TYPE_PACKED_ARRAY_TYPE_P (gnu_type) + = (Is_Packed_Array_Type (gnat_entity) + && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))); + + /* If the size is self-referential and the maximum size doesn't + overflow, use it. */ + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)) + && gnu_max_size + && !(TREE_CODE (gnu_max_size) == INTEGER_CST + && TREE_OVERFLOW (gnu_max_size)) + && !(TREE_CODE (gnu_max_size_unit) == INTEGER_CST + && TREE_OVERFLOW (gnu_max_size_unit))) + { + TYPE_SIZE (gnu_type) = size_binop (MIN_EXPR, gnu_max_size, + TYPE_SIZE (gnu_type)); + TYPE_SIZE_UNIT (gnu_type) + = size_binop (MIN_EXPR, gnu_max_size_unit, + TYPE_SIZE_UNIT (gnu_type)); + } + + /* Set our alias set to that of our base type. This gives all + array subtypes the same alias set. */ + relate_alias_sets (gnu_type, gnu_base_type, ALIAS_SET_COPY); + + /* If this is a packed type, make this type the same as the packed + array type, but do some adjusting in the type first. */ + if (Present (Packed_Array_Type (gnat_entity))) + { + Entity_Id gnat_index; + tree gnu_inner; + + /* First finish the type we had been making so that we output + debugging information for it. */ + if (Treat_As_Volatile (gnat_entity)) + gnu_type + = build_qualified_type (gnu_type, + TYPE_QUALS (gnu_type) + | TYPE_QUAL_VOLATILE); + + /* Make it artificial only if the base type was artificial too. + That's sort of "morally" true and will make it possible for + the debugger to look it up by name in DWARF, which is needed + in order to decode the packed array type. */ + gnu_decl + = create_type_decl (gnu_entity_name, gnu_type, attr_list, + !Comes_From_Source (Etype (gnat_entity)) + && !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + + /* Save it as our equivalent in case the call below elaborates + this type again. */ + save_gnu_tree (gnat_entity, gnu_decl, false); + + gnu_decl = gnat_to_gnu_entity (Packed_Array_Type (gnat_entity), + NULL_TREE, 0); + this_made_decl = true; + gnu_type = TREE_TYPE (gnu_decl); + save_gnu_tree (gnat_entity, NULL_TREE, false); + + gnu_inner = gnu_type; + while (TREE_CODE (gnu_inner) == RECORD_TYPE + && (TYPE_JUSTIFIED_MODULAR_P (gnu_inner) + || TYPE_PADDING_P (gnu_inner))) + gnu_inner = TREE_TYPE (TYPE_FIELDS (gnu_inner)); + + /* We need to attach the index type to the type we just made so + that the actual bounds can later be put into a template. */ + if ((TREE_CODE (gnu_inner) == ARRAY_TYPE + && !TYPE_ACTUAL_BOUNDS (gnu_inner)) + || (TREE_CODE (gnu_inner) == INTEGER_TYPE + && !TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner))) + { + if (TREE_CODE (gnu_inner) == INTEGER_TYPE) + { + /* The TYPE_ACTUAL_BOUNDS field is overloaded with the + TYPE_MODULUS for modular types so we make an extra + subtype if necessary. */ + if (TYPE_MODULAR_P (gnu_inner)) + { + tree gnu_subtype + = make_unsigned_type (TYPE_PRECISION (gnu_inner)); + TREE_TYPE (gnu_subtype) = gnu_inner; + TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1; + SET_TYPE_RM_MIN_VALUE (gnu_subtype, + TYPE_MIN_VALUE (gnu_inner)); + SET_TYPE_RM_MAX_VALUE (gnu_subtype, + TYPE_MAX_VALUE (gnu_inner)); + gnu_inner = gnu_subtype; + } + + TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner) = 1; + +#ifdef ENABLE_CHECKING + /* Check for other cases of overloading. */ + gcc_assert (!TYPE_ACTUAL_BOUNDS (gnu_inner)); +#endif + } + + for (gnat_index = First_Index (gnat_entity); + Present (gnat_index); + gnat_index = Next_Index (gnat_index)) + SET_TYPE_ACTUAL_BOUNDS + (gnu_inner, + tree_cons (NULL_TREE, + get_unpadded_type (Etype (gnat_index)), + TYPE_ACTUAL_BOUNDS (gnu_inner))); + + if (Convention (gnat_entity) != Convention_Fortran) + SET_TYPE_ACTUAL_BOUNDS + (gnu_inner, nreverse (TYPE_ACTUAL_BOUNDS (gnu_inner))); + + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_type)) + TREE_TYPE (TYPE_FIELDS (gnu_type)) = gnu_inner; + } + } + + else + /* Abort if packed array with no Packed_Array_Type field set. */ + gcc_assert (!Is_Packed (gnat_entity)); + } + break; + + case E_String_Literal_Subtype: + /* Create the type for a string literal. */ + { + Entity_Id gnat_full_type + = (IN (Ekind (Etype (gnat_entity)), Private_Kind) + && Present (Full_View (Etype (gnat_entity))) + ? Full_View (Etype (gnat_entity)) : Etype (gnat_entity)); + tree gnu_string_type = get_unpadded_type (gnat_full_type); + tree gnu_string_array_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_string_type)))); + tree gnu_string_index_type + = get_base_type (TREE_TYPE (TYPE_INDEX_TYPE + (TYPE_DOMAIN (gnu_string_array_type)))); + tree gnu_lower_bound + = convert (gnu_string_index_type, + gnat_to_gnu (String_Literal_Low_Bound (gnat_entity))); + int length = UI_To_Int (String_Literal_Length (gnat_entity)); + tree gnu_length = ssize_int (length - 1); + tree gnu_upper_bound + = build_binary_op (PLUS_EXPR, gnu_string_index_type, + gnu_lower_bound, + convert (gnu_string_index_type, gnu_length)); + tree gnu_index_type + = create_index_type (convert (sizetype, gnu_lower_bound), + convert (sizetype, gnu_upper_bound), + create_range_type (gnu_string_index_type, + gnu_lower_bound, + gnu_upper_bound), + gnat_entity); + + gnu_type + = build_nonshared_array_type (gnat_to_gnu_type + (Component_Type (gnat_entity)), + gnu_index_type); + if (array_type_has_nonaliased_component (gnu_type, gnat_entity)) + TYPE_NONALIASED_COMPONENT (gnu_type) = 1; + relate_alias_sets (gnu_type, gnu_string_type, ALIAS_SET_COPY); + } + break; + + /* Record Types and Subtypes + + The following fields are defined on record types: + + Has_Discriminants True if the record has discriminants + First_Discriminant Points to head of list of discriminants + First_Entity Points to head of list of fields + Is_Tagged_Type True if the record is tagged + + Implementation of Ada records and discriminated records: + + A record type definition is transformed into the equivalent of a C + struct definition. The fields that are the discriminants which are + found in the Full_Type_Declaration node and the elements of the + Component_List found in the Record_Type_Definition node. The + Component_List can be a recursive structure since each Variant of + the Variant_Part of the Component_List has a Component_List. + + Processing of a record type definition comprises starting the list of + field declarations here from the discriminants and the calling the + function components_to_record to add the rest of the fields from the + component list and return the gnu type node. The function + components_to_record will call itself recursively as it traverses + the tree. */ + + case E_Record_Type: + if (Has_Complex_Representation (gnat_entity)) + { + gnu_type + = build_complex_type + (get_unpadded_type + (Etype (Defining_Entity + (First (Component_Items + (Component_List + (Type_Definition + (Declaration_Node (gnat_entity))))))))); + + break; + } + + { + Node_Id full_definition = Declaration_Node (gnat_entity); + Node_Id record_definition = Type_Definition (full_definition); + Entity_Id gnat_field; + tree gnu_field, gnu_field_list = NULL_TREE, gnu_get_parent; + /* Set PACKED in keeping with gnat_to_gnu_field. */ + int packed + = Is_Packed (gnat_entity) + ? 1 + : Component_Alignment (gnat_entity) == Calign_Storage_Unit + ? -1 + : (Known_Alignment (gnat_entity) + || (Strict_Alignment (gnat_entity) + && Known_Static_Esize (gnat_entity))) + ? -2 + : 0; + bool has_discr = Has_Discriminants (gnat_entity); + bool has_rep = Has_Specified_Layout (gnat_entity); + bool all_rep = has_rep; + bool is_extension + = (Is_Tagged_Type (gnat_entity) + && Nkind (record_definition) == N_Derived_Type_Definition); + bool is_unchecked_union = Is_Unchecked_Union (gnat_entity); + + /* See if all fields have a rep clause. Stop when we find one + that doesn't. */ + if (all_rep) + for (gnat_field = First_Entity (gnat_entity); + Present (gnat_field); + gnat_field = Next_Entity (gnat_field)) + if ((Ekind (gnat_field) == E_Component + || Ekind (gnat_field) == E_Discriminant) + && No (Component_Clause (gnat_field))) + { + all_rep = false; + break; + } + + /* If this is a record extension, go a level further to find the + record definition. Also, verify we have a Parent_Subtype. */ + if (is_extension) + { + if (!type_annotate_only + || Present (Record_Extension_Part (record_definition))) + record_definition = Record_Extension_Part (record_definition); + + gcc_assert (type_annotate_only + || Present (Parent_Subtype (gnat_entity))); + } + + /* Make a node for the record. If we are not defining the record, + suppress expanding incomplete types. */ + gnu_type = make_node (tree_code_for_record_type (gnat_entity)); + TYPE_NAME (gnu_type) = gnu_entity_name; + TYPE_PACKED (gnu_type) = (packed != 0) || has_rep; + + if (!definition) + { + defer_incomplete_level++; + this_deferred = true; + } + + /* If both a size and rep clause was specified, put the size in + the record type now so that it can get the proper mode. */ + if (has_rep && Known_Esize (gnat_entity)) + TYPE_SIZE (gnu_type) = UI_To_gnu (Esize (gnat_entity), sizetype); + + /* Always set the alignment here so that it can be used to + set the mode, if it is making the alignment stricter. If + it is invalid, it will be checked again below. If this is to + be Atomic, choose a default alignment of a word unless we know + the size and it's smaller. */ + if (Known_Alignment (gnat_entity)) + TYPE_ALIGN (gnu_type) + = validate_alignment (Alignment (gnat_entity), gnat_entity, 0); + else if (Is_Atomic (gnat_entity)) + TYPE_ALIGN (gnu_type) + = esize >= BITS_PER_WORD ? BITS_PER_WORD : ceil_alignment (esize); + /* If a type needs strict alignment, the minimum size will be the + type size instead of the RM size (see validate_size). Cap the + alignment, lest it causes this type size to become too large. */ + else if (Strict_Alignment (gnat_entity) + && Known_Static_Esize (gnat_entity)) + { + unsigned int raw_size = UI_To_Int (Esize (gnat_entity)); + unsigned int raw_align = raw_size & -raw_size; + if (raw_align < BIGGEST_ALIGNMENT) + TYPE_ALIGN (gnu_type) = raw_align; + } + else + TYPE_ALIGN (gnu_type) = 0; + + /* If we have a Parent_Subtype, make a field for the parent. If + this record has rep clauses, force the position to zero. */ + if (Present (Parent_Subtype (gnat_entity))) + { + Entity_Id gnat_parent = Parent_Subtype (gnat_entity); + tree gnu_parent; + + /* A major complexity here is that the parent subtype will + reference our discriminants in its Discriminant_Constraint + list. But those must reference the parent component of this + record which is of the parent subtype we have not built yet! + To break the circle we first build a dummy COMPONENT_REF which + represents the "get to the parent" operation and initialize + each of those discriminants to a COMPONENT_REF of the above + dummy parent referencing the corresponding discriminant of the + base type of the parent subtype. */ + gnu_get_parent = build3 (COMPONENT_REF, void_type_node, + build0 (PLACEHOLDER_EXPR, gnu_type), + build_decl (input_location, + FIELD_DECL, NULL_TREE, + void_type_node), + NULL_TREE); + + if (has_discr) + for (gnat_field = First_Stored_Discriminant (gnat_entity); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + if (Present (Corresponding_Discriminant (gnat_field))) + { + tree gnu_field + = gnat_to_gnu_field_decl (Corresponding_Discriminant + (gnat_field)); + save_gnu_tree + (gnat_field, + build3 (COMPONENT_REF, TREE_TYPE (gnu_field), + gnu_get_parent, gnu_field, NULL_TREE), + true); + } + + /* Then we build the parent subtype. If it has discriminants but + the type itself has unknown discriminants, this means that it + doesn't contain information about how the discriminants are + derived from those of the ancestor type, so it cannot be used + directly. Instead it is built by cloning the parent subtype + of the underlying record view of the type, for which the above + derivation of discriminants has been made explicit. */ + if (Has_Discriminants (gnat_parent) + && Has_Unknown_Discriminants (gnat_entity)) + { + Entity_Id gnat_uview = Underlying_Record_View (gnat_entity); + + /* If we are defining the type, the underlying record + view must already have been elaborated at this point. + Otherwise do it now as its parent subtype cannot be + technically elaborated on its own. */ + if (definition) + gcc_assert (present_gnu_tree (gnat_uview)); + else + gnat_to_gnu_entity (gnat_uview, NULL_TREE, 0); + + gnu_parent = gnat_to_gnu_type (Parent_Subtype (gnat_uview)); + + /* Substitute the "get to the parent" of the type for that + of its underlying record view in the cloned type. */ + for (gnat_field = First_Stored_Discriminant (gnat_uview); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + if (Present (Corresponding_Discriminant (gnat_field))) + { + tree gnu_field = gnat_to_gnu_field_decl (gnat_field); + tree gnu_ref + = build3 (COMPONENT_REF, TREE_TYPE (gnu_field), + gnu_get_parent, gnu_field, NULL_TREE); + gnu_parent + = substitute_in_type (gnu_parent, gnu_field, gnu_ref); + } + } + else + gnu_parent = gnat_to_gnu_type (gnat_parent); + + /* Finally we fix up both kinds of twisted COMPONENT_REF we have + initially built. The discriminants must reference the fields + of the parent subtype and not those of its base type for the + placeholder machinery to properly work. */ + if (has_discr) + { + /* The actual parent subtype is the full view. */ + if (IN (Ekind (gnat_parent), Private_Kind)) + { + if (Present (Full_View (gnat_parent))) + gnat_parent = Full_View (gnat_parent); + else + gnat_parent = Underlying_Full_View (gnat_parent); + } + + for (gnat_field = First_Stored_Discriminant (gnat_entity); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + if (Present (Corresponding_Discriminant (gnat_field))) + { + Entity_Id field = Empty; + for (field = First_Stored_Discriminant (gnat_parent); + Present (field); + field = Next_Stored_Discriminant (field)) + if (same_discriminant_p (gnat_field, field)) + break; + gcc_assert (Present (field)); + TREE_OPERAND (get_gnu_tree (gnat_field), 1) + = gnat_to_gnu_field_decl (field); + } + } + + /* The "get to the parent" COMPONENT_REF must be given its + proper type... */ + TREE_TYPE (gnu_get_parent) = gnu_parent; + + /* ...and reference the _Parent field of this record. */ + gnu_field + = create_field_decl (parent_name_id, + gnu_parent, gnu_type, + has_rep + ? TYPE_SIZE (gnu_parent) : NULL_TREE, + has_rep + ? bitsize_zero_node : NULL_TREE, + 0, 1); + DECL_INTERNAL_P (gnu_field) = 1; + TREE_OPERAND (gnu_get_parent, 1) = gnu_field; + TYPE_FIELDS (gnu_type) = gnu_field; + } + + /* Make the fields for the discriminants and put them into the record + unless it's an Unchecked_Union. */ + if (has_discr) + for (gnat_field = First_Stored_Discriminant (gnat_entity); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + { + /* If this is a record extension and this discriminant is the + renaming of another discriminant, we've handled it above. */ + if (Present (Parent_Subtype (gnat_entity)) + && Present (Corresponding_Discriminant (gnat_field))) + continue; + + gnu_field + = gnat_to_gnu_field (gnat_field, gnu_type, packed, definition, + debug_info_p); + + /* Make an expression using a PLACEHOLDER_EXPR from the + FIELD_DECL node just created and link that with the + corresponding GNAT defining identifier. */ + save_gnu_tree (gnat_field, + build3 (COMPONENT_REF, TREE_TYPE (gnu_field), + build0 (PLACEHOLDER_EXPR, gnu_type), + gnu_field, NULL_TREE), + true); + + if (!is_unchecked_union) + { + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + } + } + + /* Add the fields into the record type and finish it up. */ + components_to_record (gnu_type, Component_List (record_definition), + gnu_field_list, packed, definition, NULL, + false, all_rep, is_unchecked_union, + debug_info_p, false); + + /* If it is passed by reference, force BLKmode to ensure that objects + of this type will always be put in memory. */ + if (Is_By_Reference_Type (gnat_entity)) + SET_TYPE_MODE (gnu_type, BLKmode); + + /* We used to remove the associations of the discriminants and _Parent + for validity checking but we may need them if there's a Freeze_Node + for a subtype used in this record. */ + TYPE_VOLATILE (gnu_type) = Treat_As_Volatile (gnat_entity); + + /* Fill in locations of fields. */ + annotate_rep (gnat_entity, gnu_type); + + /* If there are any entities in the chain corresponding to components + that we did not elaborate, ensure we elaborate their types if they + are Itypes. */ + for (gnat_temp = First_Entity (gnat_entity); + Present (gnat_temp); + gnat_temp = Next_Entity (gnat_temp)) + if ((Ekind (gnat_temp) == E_Component + || Ekind (gnat_temp) == E_Discriminant) + && Is_Itype (Etype (gnat_temp)) + && !present_gnu_tree (gnat_temp)) + gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, 0); + + /* If this is a record type associated with an exception definition, + equate its fields to those of the standard exception type. This + will make it possible to convert between them. */ + if (gnu_entity_name == exception_data_name_id) + { + tree gnu_std_field; + for (gnu_field = TYPE_FIELDS (gnu_type), + gnu_std_field = TYPE_FIELDS (except_type_node); + gnu_field; + gnu_field = DECL_CHAIN (gnu_field), + gnu_std_field = DECL_CHAIN (gnu_std_field)) + SET_DECL_ORIGINAL_FIELD_TO_FIELD (gnu_field, gnu_std_field); + gcc_assert (!gnu_std_field); + } + } + break; + + case E_Class_Wide_Subtype: + /* If an equivalent type is present, that is what we should use. + Otherwise, fall through to handle this like a record subtype + since it may have constraints. */ + if (gnat_equiv_type != gnat_entity) + { + gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, 0); + maybe_present = true; + break; + } + + /* ... fall through ... */ + + case E_Record_Subtype: + /* If Cloned_Subtype is Present it means this record subtype has + identical layout to that type or subtype and we should use + that GCC type for this one. The front end guarantees that + the component list is shared. */ + if (Present (Cloned_Subtype (gnat_entity))) + { + gnu_decl = gnat_to_gnu_entity (Cloned_Subtype (gnat_entity), + NULL_TREE, 0); + maybe_present = true; + break; + } + + /* Otherwise, first ensure the base type is elaborated. Then, if we are + changing the type, make a new type with each field having the type of + the field in the new subtype but the position computed by transforming + every discriminant reference according to the constraints. We don't + see any difference between private and non-private type here since + derivations from types should have been deferred until the completion + of the private type. */ + else + { + Entity_Id gnat_base_type = Implementation_Base_Type (gnat_entity); + tree gnu_base_type; + + if (!definition) + { + defer_incomplete_level++; + this_deferred = true; + } + + gnu_base_type = gnat_to_gnu_type (gnat_base_type); + + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + + /* If this is a record subtype associated with a dispatch table, + strip the suffix. This is necessary to make sure 2 different + subtypes associated with the imported and exported views of a + dispatch table are properly merged in LTO mode. */ + if (Is_Dispatch_Table_Entity (gnat_entity)) + { + char *p; + Get_Encoded_Name (gnat_entity); + p = strchr (Name_Buffer, '_'); + gcc_assert (p); + strcpy (p+2, "dtS"); + gnu_entity_name = get_identifier (Name_Buffer); + } + + /* When the subtype has discriminants and these discriminants affect + the initial shape it has inherited, factor them in. But for an + Unchecked_Union (it must be an Itype), just return the type. + We can't just test Is_Constrained because private subtypes without + discriminants of types with discriminants with default expressions + are Is_Constrained but aren't constrained! */ + if (IN (Ekind (gnat_base_type), Record_Kind) + && !Is_Unchecked_Union (gnat_base_type) + && !Is_For_Access_Subtype (gnat_entity) + && Is_Constrained (gnat_entity) + && Has_Discriminants (gnat_entity) + && Present (Discriminant_Constraint (gnat_entity)) + && Stored_Constraint (gnat_entity) != No_Elist) + { + VEC(subst_pair,heap) *gnu_subst_list + = build_subst_list (gnat_entity, gnat_base_type, definition); + tree gnu_unpad_base_type, gnu_rep_part, gnu_variant_part, t; + tree gnu_pos_list, gnu_field_list = NULL_TREE; + bool selected_variant = false; + Entity_Id gnat_field; + VEC(variant_desc,heap) *gnu_variant_list; + + gnu_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_type) = gnu_entity_name; + + /* Set the size, alignment and alias set of the new type to + match that of the old one, doing required substitutions. */ + copy_and_substitute_in_size (gnu_type, gnu_base_type, + gnu_subst_list); + + if (TYPE_IS_PADDING_P (gnu_base_type)) + gnu_unpad_base_type = TREE_TYPE (TYPE_FIELDS (gnu_base_type)); + else + gnu_unpad_base_type = gnu_base_type; + + /* Look for a REP part in the base type. */ + gnu_rep_part = get_rep_part (gnu_unpad_base_type); + + /* Look for a variant part in the base type. */ + gnu_variant_part = get_variant_part (gnu_unpad_base_type); + + /* If there is a variant part, we must compute whether the + constraints statically select a particular variant. If + so, we simply drop the qualified union and flatten the + list of fields. Otherwise we'll build a new qualified + union for the variants that are still relevant. */ + if (gnu_variant_part) + { + variant_desc *v; + unsigned ix; + + gnu_variant_list + = build_variant_list (TREE_TYPE (gnu_variant_part), + gnu_subst_list, NULL); + + /* If all the qualifiers are unconditionally true, the + innermost variant is statically selected. */ + selected_variant = true; + FOR_EACH_VEC_ELT_REVERSE (variant_desc, gnu_variant_list, + ix, v) + if (!integer_onep (v->qual)) + { + selected_variant = false; + break; + } + + /* Otherwise, create the new variants. */ + if (!selected_variant) + FOR_EACH_VEC_ELT_REVERSE (variant_desc, gnu_variant_list, + ix, v) + { + tree old_variant = v->type; + tree new_variant = make_node (RECORD_TYPE); + tree suffix + = concat_name (DECL_NAME (gnu_variant_part), + IDENTIFIER_POINTER + (DECL_NAME (v->field))); + TYPE_NAME (new_variant) + = concat_name (TYPE_NAME (gnu_type), + IDENTIFIER_POINTER (suffix)); + copy_and_substitute_in_size (new_variant, old_variant, + gnu_subst_list); + v->new_type = new_variant; + } + } + else + { + gnu_variant_list = NULL; + selected_variant = false; + } + + gnu_pos_list + = build_position_list (gnu_unpad_base_type, + gnu_variant_list && !selected_variant, + size_zero_node, bitsize_zero_node, + BIGGEST_ALIGNMENT, NULL_TREE); + + for (gnat_field = First_Entity (gnat_entity); + Present (gnat_field); + gnat_field = Next_Entity (gnat_field)) + if ((Ekind (gnat_field) == E_Component + || Ekind (gnat_field) == E_Discriminant) + && !(Present (Corresponding_Discriminant (gnat_field)) + && Is_Tagged_Type (gnat_base_type)) + && Underlying_Type (Scope (Original_Record_Component + (gnat_field))) + == gnat_base_type) + { + Name_Id gnat_name = Chars (gnat_field); + Entity_Id gnat_old_field + = Original_Record_Component (gnat_field); + tree gnu_old_field + = gnat_to_gnu_field_decl (gnat_old_field); + tree gnu_context = DECL_CONTEXT (gnu_old_field); + tree gnu_field, gnu_field_type, gnu_size; + tree gnu_cont_type, gnu_last = NULL_TREE; + + /* If the type is the same, retrieve the GCC type from the + old field to take into account possible adjustments. */ + if (Etype (gnat_field) == Etype (gnat_old_field)) + gnu_field_type = TREE_TYPE (gnu_old_field); + else + gnu_field_type = gnat_to_gnu_type (Etype (gnat_field)); + + /* If there was a component clause, the field types must be + the same for the type and subtype, so copy the data from + the old field to avoid recomputation here. Also if the + field is justified modular and the optimization in + gnat_to_gnu_field was applied. */ + if (Present (Component_Clause (gnat_old_field)) + || (TREE_CODE (gnu_field_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type) + && TREE_TYPE (TYPE_FIELDS (gnu_field_type)) + == TREE_TYPE (gnu_old_field))) + { + gnu_size = DECL_SIZE (gnu_old_field); + gnu_field_type = TREE_TYPE (gnu_old_field); + } + + /* If the old field was packed and of constant size, we + have to get the old size here, as it might differ from + what the Etype conveys and the latter might overlap + onto the following field. Try to arrange the type for + possible better packing along the way. */ + else if (DECL_PACKED (gnu_old_field) + && TREE_CODE (DECL_SIZE (gnu_old_field)) + == INTEGER_CST) + { + gnu_size = DECL_SIZE (gnu_old_field); + if (TREE_CODE (gnu_field_type) == RECORD_TYPE + && !TYPE_FAT_POINTER_P (gnu_field_type) + && host_integerp (TYPE_SIZE (gnu_field_type), 1)) + gnu_field_type + = make_packable_type (gnu_field_type, true); + } + + else + gnu_size = TYPE_SIZE (gnu_field_type); + + /* If the context of the old field is the base type or its + REP part (if any), put the field directly in the new + type; otherwise look up the context in the variant list + and put the field either in the new type if there is a + selected variant or in one of the new variants. */ + if (gnu_context == gnu_unpad_base_type + || (gnu_rep_part + && gnu_context == TREE_TYPE (gnu_rep_part))) + gnu_cont_type = gnu_type; + else + { + variant_desc *v; + unsigned ix; + + t = NULL_TREE; + FOR_EACH_VEC_ELT_REVERSE (variant_desc, + gnu_variant_list, ix, v) + if (v->type == gnu_context) + { + t = v->type; + break; + } + if (t) + { + if (selected_variant) + gnu_cont_type = gnu_type; + else + gnu_cont_type = v->new_type; + } + else + /* The front-end may pass us "ghost" components if + it fails to recognize that a constrained subtype + is statically constrained. Discard them. */ + continue; + } + + /* Now create the new field modeled on the old one. */ + gnu_field + = create_field_decl_from (gnu_old_field, gnu_field_type, + gnu_cont_type, gnu_size, + gnu_pos_list, gnu_subst_list); + + /* Put it in one of the new variants directly. */ + if (gnu_cont_type != gnu_type) + { + DECL_CHAIN (gnu_field) = TYPE_FIELDS (gnu_cont_type); + TYPE_FIELDS (gnu_cont_type) = gnu_field; + } + + /* To match the layout crafted in components_to_record, + if this is the _Tag or _Parent field, put it before + any other fields. */ + else if (gnat_name == Name_uTag + || gnat_name == Name_uParent) + gnu_field_list = chainon (gnu_field_list, gnu_field); + + /* Similarly, if this is the _Controller field, put + it before the other fields except for the _Tag or + _Parent field. */ + else if (gnat_name == Name_uController && gnu_last) + { + TREE_CHAIN (gnu_field) = TREE_CHAIN (gnu_last); + TREE_CHAIN (gnu_last) = gnu_field; + } + + /* Otherwise, if this is a regular field, put it after + the other fields. */ + else + { + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + if (!gnu_last) + gnu_last = gnu_field; + } + + save_gnu_tree (gnat_field, gnu_field, false); + } + + /* If there is a variant list and no selected variant, we need + to create the nest of variant parts from the old nest. */ + if (gnu_variant_list && !selected_variant) + { + tree new_variant_part + = create_variant_part_from (gnu_variant_part, + gnu_variant_list, gnu_type, + gnu_pos_list, gnu_subst_list); + DECL_CHAIN (new_variant_part) = gnu_field_list; + gnu_field_list = new_variant_part; + } + + /* Now go through the entities again looking for Itypes that + we have not elaborated but should (e.g., Etypes of fields + that have Original_Components). */ + for (gnat_field = First_Entity (gnat_entity); + Present (gnat_field); gnat_field = Next_Entity (gnat_field)) + if ((Ekind (gnat_field) == E_Discriminant + || Ekind (gnat_field) == E_Component) + && !present_gnu_tree (Etype (gnat_field))) + gnat_to_gnu_entity (Etype (gnat_field), NULL_TREE, 0); + + /* Do not emit debug info for the type yet since we're going to + modify it below. */ + gnu_field_list = nreverse (gnu_field_list); + finish_record_type (gnu_type, gnu_field_list, 2, false); + + /* See the E_Record_Type case for the rationale. */ + if (Is_By_Reference_Type (gnat_entity)) + SET_TYPE_MODE (gnu_type, BLKmode); + else + compute_record_mode (gnu_type); + + TYPE_VOLATILE (gnu_type) = Treat_As_Volatile (gnat_entity); + + /* Fill in locations of fields. */ + annotate_rep (gnat_entity, gnu_type); + + /* If debugging information is being written for the type, write + a record that shows what we are a subtype of and also make a + variable that indicates our size, if still variable. */ + if (debug_info_p) + { + tree gnu_subtype_marker = make_node (RECORD_TYPE); + tree gnu_unpad_base_name = TYPE_NAME (gnu_unpad_base_type); + tree gnu_size_unit = TYPE_SIZE_UNIT (gnu_type); + + if (TREE_CODE (gnu_unpad_base_name) == TYPE_DECL) + gnu_unpad_base_name = DECL_NAME (gnu_unpad_base_name); + + TYPE_NAME (gnu_subtype_marker) + = create_concat_name (gnat_entity, "XVS"); + finish_record_type (gnu_subtype_marker, + create_field_decl (gnu_unpad_base_name, + build_reference_type + (gnu_unpad_base_type), + gnu_subtype_marker, + NULL_TREE, NULL_TREE, + 0, 0), + 0, true); + + add_parallel_type (TYPE_STUB_DECL (gnu_type), + gnu_subtype_marker); + + if (definition + && TREE_CODE (gnu_size_unit) != INTEGER_CST + && !CONTAINS_PLACEHOLDER_P (gnu_size_unit)) + TYPE_SIZE_UNIT (gnu_subtype_marker) + = create_var_decl (create_concat_name (gnat_entity, + "XVZ"), + NULL_TREE, sizetype, gnu_size_unit, + false, false, false, false, NULL, + gnat_entity); + } + + VEC_free (variant_desc, heap, gnu_variant_list); + VEC_free (subst_pair, heap, gnu_subst_list); + + /* Now we can finalize it. */ + rest_of_record_type_compilation (gnu_type); + } + + /* Otherwise, go down all the components in the new type and make + them equivalent to those in the base type. */ + else + { + gnu_type = gnu_base_type; + + for (gnat_temp = First_Entity (gnat_entity); + Present (gnat_temp); + gnat_temp = Next_Entity (gnat_temp)) + if ((Ekind (gnat_temp) == E_Discriminant + && !Is_Unchecked_Union (gnat_base_type)) + || Ekind (gnat_temp) == E_Component) + save_gnu_tree (gnat_temp, + gnat_to_gnu_field_decl + (Original_Record_Component (gnat_temp)), + false); + } + } + break; + + case E_Access_Subprogram_Type: + /* Use the special descriptor type for dispatch tables if needed, + that is to say for the Prim_Ptr of a-tags.ads and its clones. + Note that we are only required to do so for static tables in + order to be compatible with the C++ ABI, but Ada 2005 allows + to extend library level tagged types at the local level so + we do it in the non-static case as well. */ + if (TARGET_VTABLE_USES_DESCRIPTORS + && Is_Dispatch_Table_Entity (gnat_entity)) + { + gnu_type = fdesc_type_node; + gnu_size = TYPE_SIZE (gnu_type); + break; + } + + /* ... fall through ... */ + + case E_Anonymous_Access_Subprogram_Type: + /* If we are not defining this entity, and we have incomplete + entities being processed above us, make a dummy type and + fill it in later. */ + if (!definition && defer_incomplete_level != 0) + { + struct incomplete *p + = (struct incomplete *) xmalloc (sizeof (struct incomplete)); + + gnu_type + = build_pointer_type + (make_dummy_type (Directly_Designated_Type (gnat_entity))); + gnu_decl = create_type_decl (gnu_entity_name, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + this_made_decl = true; + gnu_type = TREE_TYPE (gnu_decl); + save_gnu_tree (gnat_entity, gnu_decl, false); + saved = true; + + p->old_type = TREE_TYPE (gnu_type); + p->full_type = Directly_Designated_Type (gnat_entity); + p->next = defer_incomplete_list; + defer_incomplete_list = p; + break; + } + + /* ... fall through ... */ + + case E_Allocator_Type: + case E_Access_Type: + case E_Access_Attribute_Type: + case E_Anonymous_Access_Type: + case E_General_Access_Type: + { + /* The designated type and its equivalent type for gigi. */ + Entity_Id gnat_desig_type = Directly_Designated_Type (gnat_entity); + Entity_Id gnat_desig_equiv = Gigi_Equivalent_Type (gnat_desig_type); + /* Whether it comes from a limited with. */ + bool is_from_limited_with + = (IN (Ekind (gnat_desig_equiv), Incomplete_Kind) + && From_With_Type (gnat_desig_equiv)); + /* The "full view" of the designated type. If this is an incomplete + entity from a limited with, treat its non-limited view as the full + view. Otherwise, if this is an incomplete or private type, use the + full view. In the former case, we might point to a private type, + in which case, we need its full view. Also, we want to look at the + actual type used for the representation, so this takes a total of + three steps. */ + Entity_Id gnat_desig_full_direct_first + = (is_from_limited_with + ? Non_Limited_View (gnat_desig_equiv) + : (IN (Ekind (gnat_desig_equiv), Incomplete_Or_Private_Kind) + ? Full_View (gnat_desig_equiv) : Empty)); + Entity_Id gnat_desig_full_direct + = ((is_from_limited_with + && Present (gnat_desig_full_direct_first) + && IN (Ekind (gnat_desig_full_direct_first), Private_Kind)) + ? Full_View (gnat_desig_full_direct_first) + : gnat_desig_full_direct_first); + Entity_Id gnat_desig_full + = Gigi_Equivalent_Type (gnat_desig_full_direct); + /* The type actually used to represent the designated type, either + gnat_desig_full or gnat_desig_equiv. */ + Entity_Id gnat_desig_rep; + /* True if this is a pointer to an unconstrained array. */ + bool is_unconstrained_array; + /* We want to know if we'll be seeing the freeze node for any + incomplete type we may be pointing to. */ + bool in_main_unit + = (Present (gnat_desig_full) + ? In_Extended_Main_Code_Unit (gnat_desig_full) + : In_Extended_Main_Code_Unit (gnat_desig_type)); + /* True if we make a dummy type here. */ + bool made_dummy = false; + /* True if the dummy type is a fat pointer. */ + bool got_fat_p = false; + /* The mode to be used for the pointer type. */ + enum machine_mode p_mode = mode_for_size (esize, MODE_INT, 0); + /* The GCC type used for the designated type. */ + tree gnu_desig_type = NULL_TREE; + + if (!targetm.valid_pointer_mode (p_mode)) + p_mode = ptr_mode; + + /* If either the designated type or its full view is an unconstrained + array subtype, replace it with the type it's a subtype of. This + avoids problems with multiple copies of unconstrained array types. + Likewise, if the designated type is a subtype of an incomplete + record type, use the parent type to avoid order of elaboration + issues. This can lose some code efficiency, but there is no + alternative. */ + if (Ekind (gnat_desig_equiv) == E_Array_Subtype + && !Is_Constrained (gnat_desig_equiv)) + gnat_desig_equiv = Etype (gnat_desig_equiv); + if (Present (gnat_desig_full) + && ((Ekind (gnat_desig_full) == E_Array_Subtype + && !Is_Constrained (gnat_desig_full)) + || (Ekind (gnat_desig_full) == E_Record_Subtype + && Ekind (Etype (gnat_desig_full)) == E_Record_Type))) + gnat_desig_full = Etype (gnat_desig_full); + + /* Set the type that's actually the representation of the designated + type and also flag whether we have a unconstrained array. */ + gnat_desig_rep + = Present (gnat_desig_full) ? gnat_desig_full : gnat_desig_equiv; + is_unconstrained_array + = Is_Array_Type (gnat_desig_rep) && !Is_Constrained (gnat_desig_rep); + + /* If we are pointing to an incomplete type whose completion is an + unconstrained array, make a fat pointer type. The two types in our + fields will be pointers to dummy nodes and will be replaced in + update_pointer_to. Similarly, if the type itself is a dummy type or + an unconstrained array. Also make a dummy TYPE_OBJECT_RECORD_TYPE + in case we have any thin pointers to it. */ + if (is_unconstrained_array + && (Present (gnat_desig_full) + || (present_gnu_tree (gnat_desig_equiv) + && TYPE_IS_DUMMY_P + (TREE_TYPE (get_gnu_tree (gnat_desig_equiv)))) + || (!in_main_unit + && defer_incomplete_level != 0 + && !present_gnu_tree (gnat_desig_equiv)) + || (in_main_unit + && is_from_limited_with + && Present (Freeze_Node (gnat_desig_equiv))))) + { + if (present_gnu_tree (gnat_desig_rep)) + gnu_desig_type = TREE_TYPE (get_gnu_tree (gnat_desig_rep)); + else + { + gnu_desig_type = make_dummy_type (gnat_desig_rep); + /* Show the dummy we get will be a fat pointer. */ + got_fat_p = made_dummy = true; + } + + /* If the call above got something that has a pointer, the pointer + is our type. This could have happened either because the type + was elaborated or because somebody else executed the code. */ + gnu_type = TYPE_POINTER_TO (gnu_desig_type); + if (!gnu_type) + { + tree gnu_template_type = make_node (RECORD_TYPE); + tree gnu_ptr_template = build_pointer_type (gnu_template_type); + tree gnu_array_type = make_node (ENUMERAL_TYPE); + tree gnu_ptr_array = build_pointer_type (gnu_array_type); + tree fields; + + TYPE_NAME (gnu_template_type) + = create_concat_name (gnat_desig_equiv, "XUB"); + TYPE_DUMMY_P (gnu_template_type) = 1; + + TYPE_NAME (gnu_array_type) + = create_concat_name (gnat_desig_equiv, "XUA"); + TYPE_DUMMY_P (gnu_array_type) = 1; + + gnu_type = make_node (RECORD_TYPE); + /* Build a stub DECL to trigger the special processing for fat + pointer types in gnat_pushdecl. */ + TYPE_NAME (gnu_type) + = create_type_stub_decl + (create_concat_name (gnat_desig_equiv, "XUP"), gnu_type); + SET_TYPE_UNCONSTRAINED_ARRAY (gnu_type, gnu_desig_type); + TYPE_POINTER_TO (gnu_desig_type) = gnu_type; + + fields + = create_field_decl (get_identifier ("P_ARRAY"), + gnu_ptr_array, gnu_type, + NULL_TREE, NULL_TREE, 0, 0); + DECL_CHAIN (fields) + = create_field_decl (get_identifier ("P_BOUNDS"), + gnu_ptr_template, gnu_type, + NULL_TREE, NULL_TREE, 0, 0); + finish_fat_pointer_type (gnu_type, fields); + + TYPE_OBJECT_RECORD_TYPE (gnu_desig_type) + = make_node (RECORD_TYPE); + TYPE_NAME (TYPE_OBJECT_RECORD_TYPE (gnu_desig_type)) + = create_concat_name (gnat_desig_equiv, "XUT"); + TYPE_DUMMY_P (TYPE_OBJECT_RECORD_TYPE (gnu_desig_type)) = 1; + } + } + + /* If we already know what the full type is, use it. */ + else if (Present (gnat_desig_full) + && present_gnu_tree (gnat_desig_full)) + gnu_desig_type = TREE_TYPE (get_gnu_tree (gnat_desig_full)); + + /* Get the type of the thing we are to point to and build a pointer to + it. If it is a reference to an incomplete or private type with a + full view that is a record, make a dummy type node and get the + actual type later when we have verified it is safe. */ + else if ((!in_main_unit + && !present_gnu_tree (gnat_desig_equiv) + && Present (gnat_desig_full) + && !present_gnu_tree (gnat_desig_full) + && Is_Record_Type (gnat_desig_full)) + /* Likewise if we are pointing to a record or array and we are + to defer elaborating incomplete types. We do this as this + access type may be the full view of a private type. Note + that the unconstrained array case is handled above. */ + || ((!in_main_unit || imported_p) + && defer_incomplete_level != 0 + && !present_gnu_tree (gnat_desig_equiv) + && (Is_Record_Type (gnat_desig_rep) + || Is_Array_Type (gnat_desig_rep))) + /* If this is a reference from a limited_with type back to our + main unit and there's a freeze node for it, either we have + already processed the declaration and made the dummy type, + in which case we just reuse the latter, or we have not yet, + in which case we make the dummy type and it will be reused + when the declaration is finally processed. In both cases, + the pointer eventually created below will be automatically + adjusted when the freeze node is processed. Note that the + unconstrained array case is handled above. */ + || (in_main_unit + && is_from_limited_with + && Present (Freeze_Node (gnat_desig_rep)))) + { + gnu_desig_type = make_dummy_type (gnat_desig_equiv); + made_dummy = true; + } + + /* Otherwise handle the case of a pointer to itself. */ + else if (gnat_desig_equiv == gnat_entity) + { + gnu_type + = build_pointer_type_for_mode (void_type_node, p_mode, + No_Strict_Aliasing (gnat_entity)); + TREE_TYPE (gnu_type) = TYPE_POINTER_TO (gnu_type) = gnu_type; + } + + /* If expansion is disabled, the equivalent type of a concurrent type + is absent, so build a dummy pointer type. */ + else if (type_annotate_only && No (gnat_desig_equiv)) + gnu_type = ptr_void_type_node; + + /* Finally, handle the default case where we can just elaborate our + designated type. */ + else + gnu_desig_type = gnat_to_gnu_type (gnat_desig_equiv); + + /* It is possible that a call to gnat_to_gnu_type above resolved our + type. If so, just return it. */ + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + + /* If we have not done it yet, build the pointer type the usual way. */ + if (!gnu_type) + { + /* Modify the designated type if we are pointing only to constant + objects, but don't do it for unconstrained arrays. */ + if (Is_Access_Constant (gnat_entity) + && TREE_CODE (gnu_desig_type) != UNCONSTRAINED_ARRAY_TYPE) + { + gnu_desig_type + = build_qualified_type + (gnu_desig_type, + TYPE_QUALS (gnu_desig_type) | TYPE_QUAL_CONST); + + /* Some extra processing is required if we are building a + pointer to an incomplete type (in the GCC sense). We might + have such a type if we just made a dummy, or directly out + of the call to gnat_to_gnu_type above if we are processing + an access type for a record component designating the + record type itself. */ + if (TYPE_MODE (gnu_desig_type) == VOIDmode) + { + /* We must ensure that the pointer to variant we make will + be processed by update_pointer_to when the initial type + is completed. Pretend we made a dummy and let further + processing act as usual. */ + made_dummy = true; + + /* We must ensure that update_pointer_to will not retrieve + the dummy variant when building a properly qualified + version of the complete type. We take advantage of the + fact that get_qualified_type is requiring TYPE_NAMEs to + match to influence build_qualified_type and then also + update_pointer_to here. */ + TYPE_NAME (gnu_desig_type) + = create_concat_name (gnat_desig_type, "INCOMPLETE_CST"); + } + } + + gnu_type + = build_pointer_type_for_mode (gnu_desig_type, p_mode, + No_Strict_Aliasing (gnat_entity)); + } + + /* If we are not defining this object and we have made a dummy pointer, + save our current definition, evaluate the actual type, and replace + the tentative type we made with the actual one. If we are to defer + actually looking up the actual type, make an entry in the deferred + list. If this is from a limited with, we have to defer to the end + of the current spec in two cases: first if the designated type is + in the current unit and second if the access type itself is. */ + if ((!in_main_unit || is_from_limited_with) && made_dummy) + { + bool is_from_limited_with_in_main_unit + = (is_from_limited_with + && (in_main_unit + || In_Extended_Main_Code_Unit (gnat_entity))); + tree gnu_old_desig_type + = TYPE_IS_FAT_POINTER_P (gnu_type) + ? TYPE_UNCONSTRAINED_ARRAY (gnu_type) : TREE_TYPE (gnu_type); + + if (esize == POINTER_SIZE + && (got_fat_p || TYPE_IS_FAT_POINTER_P (gnu_type))) + gnu_type + = build_pointer_type + (TYPE_OBJECT_RECORD_TYPE + (TYPE_UNCONSTRAINED_ARRAY (gnu_type))); + + gnu_decl = create_type_decl (gnu_entity_name, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + this_made_decl = true; + gnu_type = TREE_TYPE (gnu_decl); + save_gnu_tree (gnat_entity, gnu_decl, false); + saved = true; + + /* Note that the call to gnat_to_gnu_type on gnat_desig_equiv might + update gnu_old_desig_type directly, in which case it will not be + a dummy type any more when we get into update_pointer_to. + + This can happen e.g. when the designated type is a record type, + because their elaboration starts with an initial node from + make_dummy_type, which may be the same node as the one we got. + + Besides, variants of this non-dummy type might have been created + along the way. update_pointer_to is expected to properly take + care of those situations. */ + if (defer_incomplete_level == 0 + && !is_from_limited_with_in_main_unit) + update_pointer_to (TYPE_MAIN_VARIANT (gnu_old_desig_type), + gnat_to_gnu_type (gnat_desig_equiv)); + else + { + struct incomplete *p = XNEW (struct incomplete); + struct incomplete **head + = (is_from_limited_with_in_main_unit + ? &defer_limited_with : &defer_incomplete_list); + p->old_type = gnu_old_desig_type; + p->full_type = gnat_desig_equiv; + p->next = *head; + *head = p; + } + } + } + break; + + case E_Access_Protected_Subprogram_Type: + case E_Anonymous_Access_Protected_Subprogram_Type: + if (type_annotate_only && No (gnat_equiv_type)) + gnu_type = ptr_void_type_node; + else + { + /* The run-time representation is the equivalent type. */ + gnu_type = gnat_to_gnu_type (gnat_equiv_type); + maybe_present = true; + } + + if (Is_Itype (Directly_Designated_Type (gnat_entity)) + && !present_gnu_tree (Directly_Designated_Type (gnat_entity)) + && No (Freeze_Node (Directly_Designated_Type (gnat_entity))) + && !Is_Record_Type (Scope (Directly_Designated_Type (gnat_entity)))) + gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity), + NULL_TREE, 0); + + break; + + case E_Access_Subtype: + + /* We treat this as identical to its base type; any constraint is + meaningful only to the front end. + + The designated type must be elaborated as well, if it does + not have its own freeze node. Designated (sub)types created + for constrained components of records with discriminants are + not frozen by the front end and thus not elaborated by gigi, + because their use may appear before the base type is frozen, + and because it is not clear that they are needed anywhere in + Gigi. With the current model, there is no correct place where + they could be elaborated. */ + + gnu_type = gnat_to_gnu_type (Etype (gnat_entity)); + if (Is_Itype (Directly_Designated_Type (gnat_entity)) + && !present_gnu_tree (Directly_Designated_Type (gnat_entity)) + && Is_Frozen (Directly_Designated_Type (gnat_entity)) + && No (Freeze_Node (Directly_Designated_Type (gnat_entity)))) + { + /* If we are not defining this entity, and we have incomplete + entities being processed above us, make a dummy type and + elaborate it later. */ + if (!definition && defer_incomplete_level != 0) + { + struct incomplete *p + = (struct incomplete *) xmalloc (sizeof (struct incomplete)); + tree gnu_ptr_type + = build_pointer_type + (make_dummy_type (Directly_Designated_Type (gnat_entity))); + + p->old_type = TREE_TYPE (gnu_ptr_type); + p->full_type = Directly_Designated_Type (gnat_entity); + p->next = defer_incomplete_list; + defer_incomplete_list = p; + } + else if (!IN (Ekind (Base_Type + (Directly_Designated_Type (gnat_entity))), + Incomplete_Or_Private_Kind)) + gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity), + NULL_TREE, 0); + } + + maybe_present = true; + break; + + /* Subprogram Entities + + The following access functions are defined for subprograms: + + Etype Return type or Standard_Void_Type. + First_Formal The first formal parameter. + Is_Imported Indicates that the subprogram has appeared in + an INTERFACE or IMPORT pragma. For now we + assume that the external language is C. + Is_Exported Likewise but for an EXPORT pragma. + Is_Inlined True if the subprogram is to be inlined. + + Each parameter is first checked by calling must_pass_by_ref on its + type to determine if it is passed by reference. For parameters which + are copied in, if they are Ada In Out or Out parameters, their return + value becomes part of a record which becomes the return type of the + function (C function - note that this applies only to Ada procedures + so there is no Ada return type). Additional code to store back the + parameters will be generated on the caller side. This transformation + is done here, not in the front-end. + + The intended result of the transformation can be seen from the + equivalent source rewritings that follow: + + struct temp {int a,b}; + procedure P (A,B: In Out ...) is temp P (int A,B) + begin { + .. .. + end P; return {A,B}; + } + + temp t; + P(X,Y); t = P(X,Y); + X = t.a , Y = t.b; + + For subprogram types we need to perform mainly the same conversions to + GCC form that are needed for procedures and function declarations. The + only difference is that at the end, we make a type declaration instead + of a function declaration. */ + + case E_Subprogram_Type: + case E_Function: + case E_Procedure: + { + /* The type returned by a function or else Standard_Void_Type for a + procedure. */ + Entity_Id gnat_return_type = Etype (gnat_entity); + tree gnu_return_type; + /* The first GCC parameter declaration (a PARM_DECL node). The + PARM_DECL nodes are chained through the TREE_CHAIN field, so this + actually is the head of this parameter list. */ + tree gnu_param_list = NULL_TREE; + /* Likewise for the stub associated with an exported procedure. */ + tree gnu_stub_param_list = NULL_TREE; + /* Non-null for subprograms containing parameters passed by copy-in + copy-out (Ada In Out or Out parameters not passed by reference), + in which case it is the list of nodes used to specify the values + of the In Out/Out parameters that are returned as a record upon + procedure return. The TREE_PURPOSE of an element of this list is + a field of the record and the TREE_VALUE is the PARM_DECL + corresponding to that field. This list will be saved in the + TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */ + tree gnu_cico_list = NULL_TREE; + /* List of fields in return type of procedure with copy-in copy-out + parameters. */ + tree gnu_field_list = NULL_TREE; + /* If an import pragma asks to map this subprogram to a GCC builtin, + this is the builtin DECL node. */ + tree gnu_builtin_decl = NULL_TREE; + /* For the stub associated with an exported procedure. */ + tree gnu_stub_type = NULL_TREE, gnu_stub_name = NULL_TREE; + tree gnu_ext_name = create_concat_name (gnat_entity, NULL); + Entity_Id gnat_param; + bool inline_flag = Is_Inlined (gnat_entity); + bool public_flag = Is_Public (gnat_entity) || imported_p; + bool extern_flag + = (Is_Public (gnat_entity) && !definition) || imported_p; + /* The semantics of "pure" in Ada essentially matches that of "const" + in the back-end. In particular, both properties are orthogonal to + the "nothrow" property if the EH circuitry is explicit in the + internal representation of the back-end. If we are to completely + hide the EH circuitry from it, we need to declare that calls to pure + Ada subprograms that can throw have side effects since they can + trigger an "abnormal" transfer of control flow; thus they can be + neither "const" nor "pure" in the back-end sense. */ + bool const_flag + = (Exception_Mechanism == Back_End_Exceptions + && Is_Pure (gnat_entity)); + bool volatile_flag = No_Return (gnat_entity); + bool return_by_direct_ref_p = false; + bool return_by_invisi_ref_p = false; + bool return_unconstrained_p = false; + bool has_stub = false; + int parmnum; + + /* A parameter may refer to this type, so defer completion of any + incomplete types. */ + if (kind == E_Subprogram_Type && !definition) + { + defer_incomplete_level++; + this_deferred = true; + } + + /* If the subprogram has an alias, it is probably inherited, so + we can use the original one. If the original "subprogram" + is actually an enumeration literal, it may be the first use + of its type, so we must elaborate that type now. */ + if (Present (Alias (gnat_entity))) + { + if (Ekind (Alias (gnat_entity)) == E_Enumeration_Literal) + gnat_to_gnu_entity (Etype (Alias (gnat_entity)), NULL_TREE, 0); + + gnu_decl = gnat_to_gnu_entity (Alias (gnat_entity), gnu_expr, 0); + + /* Elaborate any Itypes in the parameters of this entity. */ + for (gnat_temp = First_Formal_With_Extras (gnat_entity); + Present (gnat_temp); + gnat_temp = Next_Formal_With_Extras (gnat_temp)) + if (Is_Itype (Etype (gnat_temp))) + gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, 0); + + break; + } + + /* If this subprogram is expectedly bound to a GCC builtin, fetch the + corresponding DECL node. Proper generation of calls later on need + proper parameter associations so we don't "break;" here. */ + if (Convention (gnat_entity) == Convention_Intrinsic + && Present (Interface_Name (gnat_entity))) + { + gnu_builtin_decl = builtin_decl_for (gnu_ext_name); + + /* Inability to find the builtin decl most often indicates a + genuine mistake, but imports of unregistered intrinsics are + sometimes issued on purpose to allow hooking in alternate + bodies. We post a warning conditioned on Wshadow in this case, + to let developers be notified on demand without risking false + positives with common default sets of options. */ + + if (gnu_builtin_decl == NULL_TREE && warn_shadow) + post_error ("?gcc intrinsic not found for&!", gnat_entity); + } + + /* ??? What if we don't find the builtin node above ? warn ? err ? + In the current state we neither warn nor err, and calls will just + be handled as for regular subprograms. */ + + /* Look into the return type and get its associated GCC tree. If it + is not void, compute various flags for the subprogram type. */ + if (Ekind (gnat_return_type) == E_Void) + gnu_return_type = void_type_node; + else + { + gnu_return_type = gnat_to_gnu_type (gnat_return_type); + + /* If this function returns by reference, make the actual return + type the pointer type and make a note of that. */ + if (Returns_By_Ref (gnat_entity)) + { + gnu_return_type = build_pointer_type (gnu_return_type); + return_by_direct_ref_p = true; + } + + /* If we are supposed to return an unconstrained array type, make + the actual return type the fat pointer type. */ + else if (TREE_CODE (gnu_return_type) == UNCONSTRAINED_ARRAY_TYPE) + { + gnu_return_type = TREE_TYPE (gnu_return_type); + return_unconstrained_p = true; + } + + /* Likewise, if the return type requires a transient scope, the + return value will be allocated on the secondary stack so the + actual return type is the pointer type. */ + else if (Requires_Transient_Scope (gnat_return_type)) + { + gnu_return_type = build_pointer_type (gnu_return_type); + return_unconstrained_p = true; + } + + /* If the Mechanism is By_Reference, ensure this function uses the + target's by-invisible-reference mechanism, which may not be the + same as above (e.g. it might be passing an extra parameter). */ + else if (kind == E_Function + && Mechanism (gnat_entity) == By_Reference) + return_by_invisi_ref_p = true; + + /* Likewise, if the return type is itself By_Reference. */ + else if (TREE_ADDRESSABLE (gnu_return_type)) + return_by_invisi_ref_p = true; + + /* If the type is a padded type and the underlying type would not + be passed by reference or the function has a foreign convention, + return the underlying type. */ + else if (TYPE_IS_PADDING_P (gnu_return_type) + && (!default_pass_by_ref + (TREE_TYPE (TYPE_FIELDS (gnu_return_type))) + || Has_Foreign_Convention (gnat_entity))) + gnu_return_type = TREE_TYPE (TYPE_FIELDS (gnu_return_type)); + + /* If the return type is unconstrained, that means it must have a + maximum size. Use the padded type as the effective return type. + And ensure the function uses the target's by-invisible-reference + mechanism to avoid copying too much data when it returns. */ + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_return_type))) + { + gnu_return_type + = maybe_pad_type (gnu_return_type, + max_size (TYPE_SIZE (gnu_return_type), + true), + 0, gnat_entity, false, false, false, true); + return_by_invisi_ref_p = true; + } + + /* If the return type has a size that overflows, we cannot have + a function that returns that type. This usage doesn't make + sense anyway, so give an error here. */ + if (TYPE_SIZE_UNIT (gnu_return_type) + && TREE_CONSTANT (TYPE_SIZE_UNIT (gnu_return_type)) + && TREE_OVERFLOW (TYPE_SIZE_UNIT (gnu_return_type))) + { + post_error ("cannot return type whose size overflows", + gnat_entity); + gnu_return_type = copy_node (gnu_return_type); + TYPE_SIZE (gnu_return_type) = bitsize_zero_node; + TYPE_SIZE_UNIT (gnu_return_type) = size_zero_node; + TYPE_MAIN_VARIANT (gnu_return_type) = gnu_return_type; + TYPE_NEXT_VARIANT (gnu_return_type) = NULL_TREE; + } + } + + /* Loop over the parameters and get their associated GCC tree. While + doing this, build a copy-in copy-out structure if we need one. */ + for (gnat_param = First_Formal_With_Extras (gnat_entity), parmnum = 0; + Present (gnat_param); + gnat_param = Next_Formal_With_Extras (gnat_param), parmnum++) + { + tree gnu_param_name = get_entity_name (gnat_param); + tree gnu_param_type = gnat_to_gnu_type (Etype (gnat_param)); + tree gnu_param, gnu_field; + bool copy_in_copy_out = false; + Mechanism_Type mech = Mechanism (gnat_param); + + /* Builtins are expanded inline and there is no real call sequence + involved. So the type expected by the underlying expander is + always the type of each argument "as is". */ + if (gnu_builtin_decl) + mech = By_Copy; + /* Handle the first parameter of a valued procedure specially. */ + else if (Is_Valued_Procedure (gnat_entity) && parmnum == 0) + mech = By_Copy_Return; + /* Otherwise, see if a Mechanism was supplied that forced this + parameter to be passed one way or another. */ + else if (mech == Default + || mech == By_Copy || mech == By_Reference) + ; + else if (By_Descriptor_Last <= mech && mech <= By_Descriptor) + mech = By_Descriptor; + + else if (By_Short_Descriptor_Last <= mech && + mech <= By_Short_Descriptor) + mech = By_Short_Descriptor; + + else if (mech > 0) + { + if (TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE + || TREE_CODE (TYPE_SIZE (gnu_param_type)) != INTEGER_CST + || 0 < compare_tree_int (TYPE_SIZE (gnu_param_type), + mech)) + mech = By_Reference; + else + mech = By_Copy; + } + else + { + post_error ("unsupported mechanism for&", gnat_param); + mech = Default; + } + + gnu_param + = gnat_to_gnu_param (gnat_param, mech, gnat_entity, + Has_Foreign_Convention (gnat_entity), + ©_in_copy_out); + + /* We are returned either a PARM_DECL or a type if no parameter + needs to be passed; in either case, adjust the type. */ + if (DECL_P (gnu_param)) + gnu_param_type = TREE_TYPE (gnu_param); + else + { + gnu_param_type = gnu_param; + gnu_param = NULL_TREE; + } + + /* The failure of this assertion will very likely come from an + order of elaboration issue for the type of the parameter. */ + gcc_assert (kind == E_Subprogram_Type + || !TYPE_IS_DUMMY_P (gnu_param_type)); + + if (gnu_param) + { + /* If it's an exported subprogram, we build a parameter list + in parallel, in case we need to emit a stub for it. */ + if (Is_Exported (gnat_entity)) + { + gnu_stub_param_list + = chainon (gnu_param, gnu_stub_param_list); + /* Change By_Descriptor parameter to By_Reference for + the internal version of an exported subprogram. */ + if (mech == By_Descriptor || mech == By_Short_Descriptor) + { + gnu_param + = gnat_to_gnu_param (gnat_param, By_Reference, + gnat_entity, false, + ©_in_copy_out); + has_stub = true; + } + else + gnu_param = copy_node (gnu_param); + } + + gnu_param_list = chainon (gnu_param, gnu_param_list); + Sloc_to_locus (Sloc (gnat_param), + &DECL_SOURCE_LOCATION (gnu_param)); + save_gnu_tree (gnat_param, gnu_param, false); + + /* If a parameter is a pointer, this function may modify + memory through it and thus shouldn't be considered + a const function. Also, the memory may be modified + between two calls, so they can't be CSE'ed. The latter + case also handles by-ref parameters. */ + if (POINTER_TYPE_P (gnu_param_type) + || TYPE_IS_FAT_POINTER_P (gnu_param_type)) + const_flag = false; + } + + if (copy_in_copy_out) + { + if (!gnu_cico_list) + { + tree gnu_new_ret_type = make_node (RECORD_TYPE); + + /* If this is a function, we also need a field for the + return value to be placed. */ + if (TREE_CODE (gnu_return_type) != VOID_TYPE) + { + gnu_field + = create_field_decl (get_identifier ("RETVAL"), + gnu_return_type, + gnu_new_ret_type, NULL_TREE, + NULL_TREE, 0, 0); + Sloc_to_locus (Sloc (gnat_entity), + &DECL_SOURCE_LOCATION (gnu_field)); + gnu_field_list = gnu_field; + gnu_cico_list + = tree_cons (gnu_field, void_type_node, NULL_TREE); + } + + gnu_return_type = gnu_new_ret_type; + TYPE_NAME (gnu_return_type) = get_identifier ("RETURN"); + /* Set a default alignment to speed up accesses. */ + TYPE_ALIGN (gnu_return_type) + = get_mode_alignment (ptr_mode); + } + + gnu_field + = create_field_decl (gnu_param_name, gnu_param_type, + gnu_return_type, NULL_TREE, NULL_TREE, + 0, 0); + Sloc_to_locus (Sloc (gnat_param), + &DECL_SOURCE_LOCATION (gnu_field)); + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + gnu_cico_list + = tree_cons (gnu_field, gnu_param, gnu_cico_list); + } + } + + /* Do not compute record for out parameters if subprogram is + stubbed since structures are incomplete for the back-end. */ + if (gnu_field_list && Convention (gnat_entity) != Convention_Stubbed) + finish_record_type (gnu_return_type, nreverse (gnu_field_list), + 0, debug_info_p); + + /* If we have a CICO list but it has only one entry, we convert + this function into a function that simply returns that one + object. */ + if (list_length (gnu_cico_list) == 1) + gnu_return_type = TREE_TYPE (TREE_PURPOSE (gnu_cico_list)); + + if (Has_Stdcall_Convention (gnat_entity)) + prepend_one_attribute_to + (&attr_list, ATTR_MACHINE_ATTRIBUTE, + get_identifier ("stdcall"), NULL_TREE, + gnat_entity); + + /* If we should request stack realignment for a foreign convention + subprogram, do so. Note that this applies to task entry points in + particular. */ + if (FOREIGN_FORCE_REALIGN_STACK + && Has_Foreign_Convention (gnat_entity)) + prepend_one_attribute_to + (&attr_list, ATTR_MACHINE_ATTRIBUTE, + get_identifier ("force_align_arg_pointer"), NULL_TREE, + gnat_entity); + + /* The lists have been built in reverse. */ + gnu_param_list = nreverse (gnu_param_list); + if (has_stub) + gnu_stub_param_list = nreverse (gnu_stub_param_list); + gnu_cico_list = nreverse (gnu_cico_list); + + if (kind == E_Function) + Set_Mechanism (gnat_entity, return_unconstrained_p + || return_by_direct_ref_p + || return_by_invisi_ref_p + ? By_Reference : By_Copy); + gnu_type + = create_subprog_type (gnu_return_type, gnu_param_list, + gnu_cico_list, return_unconstrained_p, + return_by_direct_ref_p, + return_by_invisi_ref_p); + + if (has_stub) + gnu_stub_type + = create_subprog_type (gnu_return_type, gnu_stub_param_list, + gnu_cico_list, return_unconstrained_p, + return_by_direct_ref_p, + return_by_invisi_ref_p); + + /* A subprogram (something that doesn't return anything) shouldn't + be considered const since there would be no reason for such a + subprogram. Note that procedures with Out (or In Out) parameters + have already been converted into a function with a return type. */ + if (TREE_CODE (gnu_return_type) == VOID_TYPE) + const_flag = false; + + gnu_type + = build_qualified_type (gnu_type, + TYPE_QUALS (gnu_type) + | (TYPE_QUAL_CONST * const_flag) + | (TYPE_QUAL_VOLATILE * volatile_flag)); + + if (has_stub) + gnu_stub_type + = build_qualified_type (gnu_stub_type, + TYPE_QUALS (gnu_stub_type) + | (TYPE_QUAL_CONST * const_flag) + | (TYPE_QUAL_VOLATILE * volatile_flag)); + + /* If we have a builtin decl for that function, use it. Check if the + profiles are compatible and warn if they are not. The checker is + expected to post extra diagnostics in this case. */ + if (gnu_builtin_decl) + { + intrin_binding_t inb; + + inb.gnat_entity = gnat_entity; + inb.ada_fntype = gnu_type; + inb.btin_fntype = TREE_TYPE (gnu_builtin_decl); + + if (!intrin_profiles_compatible_p (&inb)) + post_error + ("?profile of& doesn''t match the builtin it binds!", + gnat_entity); + + gnu_decl = gnu_builtin_decl; + gnu_type = TREE_TYPE (gnu_builtin_decl); + break; + } + + /* If there was no specified Interface_Name and the external and + internal names of the subprogram are the same, only use the + internal name to allow disambiguation of nested subprograms. */ + if (No (Interface_Name (gnat_entity)) + && gnu_ext_name == gnu_entity_name) + gnu_ext_name = NULL_TREE; + + /* If we are defining the subprogram and it has an Address clause + we must get the address expression from the saved GCC tree for the + subprogram if it has a Freeze_Node. Otherwise, we elaborate + the address expression here since the front-end has guaranteed + in that case that the elaboration has no effects. If there is + an Address clause and we are not defining the object, just + make it a constant. */ + if (Present (Address_Clause (gnat_entity))) + { + tree gnu_address = NULL_TREE; + + if (definition) + gnu_address + = (present_gnu_tree (gnat_entity) + ? get_gnu_tree (gnat_entity) + : gnat_to_gnu (Expression (Address_Clause (gnat_entity)))); + + save_gnu_tree (gnat_entity, NULL_TREE, false); + + /* Convert the type of the object to a reference type that can + alias everything as per 13.3(19). */ + gnu_type + = build_reference_type_for_mode (gnu_type, ptr_mode, true); + if (gnu_address) + gnu_address = convert (gnu_type, gnu_address); + + gnu_decl + = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type, + gnu_address, false, Is_Public (gnat_entity), + extern_flag, false, NULL, gnat_entity); + DECL_BY_REF_P (gnu_decl) = 1; + } + + else if (kind == E_Subprogram_Type) + gnu_decl = create_type_decl (gnu_entity_name, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + else + { + if (has_stub) + { + gnu_stub_name = gnu_ext_name; + gnu_ext_name = create_concat_name (gnat_entity, "internal"); + public_flag = false; + } + + gnu_decl = create_subprog_decl (gnu_entity_name, gnu_ext_name, + gnu_type, gnu_param_list, + inline_flag, public_flag, + extern_flag, attr_list, + gnat_entity); + if (has_stub) + { + tree gnu_stub_decl + = create_subprog_decl (gnu_entity_name, gnu_stub_name, + gnu_stub_type, gnu_stub_param_list, + inline_flag, true, + extern_flag, attr_list, + gnat_entity); + SET_DECL_FUNCTION_STUB (gnu_decl, gnu_stub_decl); + } + + /* This is unrelated to the stub built right above. */ + DECL_STUBBED_P (gnu_decl) + = Convention (gnat_entity) == Convention_Stubbed; + } + } + break; + + case E_Incomplete_Type: + case E_Incomplete_Subtype: + case E_Private_Type: + case E_Private_Subtype: + case E_Limited_Private_Type: + case E_Limited_Private_Subtype: + case E_Record_Type_With_Private: + case E_Record_Subtype_With_Private: + { + /* Get the "full view" of this entity. If this is an incomplete + entity from a limited with, treat its non-limited view as the + full view. Otherwise, use either the full view or the underlying + full view, whichever is present. This is used in all the tests + below. */ + Entity_Id full_view + = (IN (kind, Incomplete_Kind) && From_With_Type (gnat_entity)) + ? Non_Limited_View (gnat_entity) + : Present (Full_View (gnat_entity)) + ? Full_View (gnat_entity) + : Underlying_Full_View (gnat_entity); + + /* If this is an incomplete type with no full view, it must be a Taft + Amendment type, in which case we return a dummy type. Otherwise, + just get the type from its Etype. */ + if (No (full_view)) + { + if (kind == E_Incomplete_Type) + { + gnu_type = make_dummy_type (gnat_entity); + gnu_decl = TYPE_STUB_DECL (gnu_type); + } + else + { + gnu_decl = gnat_to_gnu_entity (Etype (gnat_entity), + NULL_TREE, 0); + maybe_present = true; + } + break; + } + + /* If we already made a type for the full view, reuse it. */ + else if (present_gnu_tree (full_view)) + { + gnu_decl = get_gnu_tree (full_view); + break; + } + + /* Otherwise, if we are not defining the type now, get the type + from the full view. But always get the type from the full view + for define on use types, since otherwise we won't see them! */ + else if (!definition + || (Is_Itype (full_view) + && No (Freeze_Node (gnat_entity))) + || (Is_Itype (gnat_entity) + && No (Freeze_Node (full_view)))) + { + gnu_decl = gnat_to_gnu_entity (full_view, NULL_TREE, 0); + maybe_present = true; + break; + } + + /* For incomplete types, make a dummy type entry which will be + replaced later. Save it as the full declaration's type so + we can do any needed updates when we see it. */ + gnu_type = make_dummy_type (gnat_entity); + gnu_decl = TYPE_STUB_DECL (gnu_type); + save_gnu_tree (full_view, gnu_decl, 0); + break; + } + + case E_Class_Wide_Type: + /* Class-wide types are always transformed into their root type. */ + gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, 0); + maybe_present = true; + break; + + case E_Task_Type: + case E_Task_Subtype: + case E_Protected_Type: + case E_Protected_Subtype: + /* Concurrent types are always transformed into their record type. */ + if (type_annotate_only && No (gnat_equiv_type)) + gnu_type = void_type_node; + else + gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, 0); + maybe_present = true; + break; + + case E_Label: + gnu_decl = create_label_decl (gnu_entity_name); + break; + + case E_Block: + case E_Loop: + /* Nothing at all to do here, so just return an ERROR_MARK and claim + we've already saved it, so we don't try to. */ + gnu_decl = error_mark_node; + saved = true; + break; + + default: + gcc_unreachable (); + } + + /* If we had a case where we evaluated another type and it might have + defined this one, handle it here. */ + if (maybe_present && present_gnu_tree (gnat_entity)) + { + gnu_decl = get_gnu_tree (gnat_entity); + saved = true; + } + + /* If we are processing a type and there is either no decl for it or + we just made one, do some common processing for the type, such as + handling alignment and possible padding. */ + if (is_type && (!gnu_decl || this_made_decl)) + { + /* Tell the middle-end that objects of tagged types are guaranteed to + be properly aligned. This is necessary because conversions to the + class-wide type are translated into conversions to the root type, + which can be less aligned than some of its derived types. */ + if (Is_Tagged_Type (gnat_entity) + || Is_Class_Wide_Equivalent_Type (gnat_entity)) + TYPE_ALIGN_OK (gnu_type) = 1; + + /* If the type is passed by reference, objects of this type must be + fully addressable and cannot be copied. */ + if (Is_By_Reference_Type (gnat_entity)) + TREE_ADDRESSABLE (gnu_type) = 1; + + /* ??? Don't set the size for a String_Literal since it is either + confirming or we don't handle it properly (if the low bound is + non-constant). */ + if (!gnu_size && kind != E_String_Literal_Subtype) + gnu_size = validate_size (Esize (gnat_entity), gnu_type, gnat_entity, + TYPE_DECL, false, + Has_Size_Clause (gnat_entity)); + + /* If a size was specified, see if we can make a new type of that size + by rearranging the type, for example from a fat to a thin pointer. */ + if (gnu_size) + { + gnu_type + = make_type_from_size (gnu_type, gnu_size, + Has_Biased_Representation (gnat_entity)); + + if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0) + && operand_equal_p (rm_size (gnu_type), gnu_size, 0)) + gnu_size = 0; + } + + /* If the alignment hasn't already been processed and this is + not an unconstrained array, see if an alignment is specified. + If not, we pick a default alignment for atomic objects. */ + if (align != 0 || TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE) + ; + else if (Known_Alignment (gnat_entity)) + { + align = validate_alignment (Alignment (gnat_entity), gnat_entity, + TYPE_ALIGN (gnu_type)); + + /* Warn on suspiciously large alignments. This should catch + errors about the (alignment,byte)/(size,bit) discrepancy. */ + if (align > BIGGEST_ALIGNMENT && Has_Alignment_Clause (gnat_entity)) + { + tree size; + + /* If a size was specified, take it into account. Otherwise + use the RM size for records as the type size has already + been adjusted to the alignment. */ + if (gnu_size) + size = gnu_size; + else if ((TREE_CODE (gnu_type) == RECORD_TYPE + || TREE_CODE (gnu_type) == UNION_TYPE + || TREE_CODE (gnu_type) == QUAL_UNION_TYPE) + && !TYPE_FAT_POINTER_P (gnu_type)) + size = rm_size (gnu_type); + else + size = TYPE_SIZE (gnu_type); + + /* Consider an alignment as suspicious if the alignment/size + ratio is greater or equal to the byte/bit ratio. */ + if (host_integerp (size, 1) + && align >= TREE_INT_CST_LOW (size) * BITS_PER_UNIT) + post_error_ne ("?suspiciously large alignment specified for&", + Expression (Alignment_Clause (gnat_entity)), + gnat_entity); + } + } + else if (Is_Atomic (gnat_entity) && !gnu_size + && host_integerp (TYPE_SIZE (gnu_type), 1) + && integer_pow2p (TYPE_SIZE (gnu_type))) + align = MIN (BIGGEST_ALIGNMENT, + tree_low_cst (TYPE_SIZE (gnu_type), 1)); + else if (Is_Atomic (gnat_entity) && gnu_size + && host_integerp (gnu_size, 1) + && integer_pow2p (gnu_size)) + align = MIN (BIGGEST_ALIGNMENT, tree_low_cst (gnu_size, 1)); + + /* See if we need to pad the type. If we did, and made a record, + the name of the new type may be changed. So get it back for + us when we make the new TYPE_DECL below. */ + if (gnu_size || align > 0) + gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity, + false, !gnu_decl, definition, false); + + if (TYPE_IS_PADDING_P (gnu_type)) + { + gnu_entity_name = TYPE_NAME (gnu_type); + if (TREE_CODE (gnu_entity_name) == TYPE_DECL) + gnu_entity_name = DECL_NAME (gnu_entity_name); + } + + set_rm_size (RM_Size (gnat_entity), gnu_type, gnat_entity); + + /* If we are at global level, GCC will have applied variable_size to + the type, but that won't have done anything. So, if it's not + a constant or self-referential, call elaborate_expression_1 to + make a variable for the size rather than calculating it each time. + Handle both the RM size and the actual size. */ + if (global_bindings_p () + && TYPE_SIZE (gnu_type) + && !TREE_CONSTANT (TYPE_SIZE (gnu_type)) + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))) + { + tree size = TYPE_SIZE (gnu_type); + + TYPE_SIZE (gnu_type) + = elaborate_expression_1 (size, gnat_entity, + get_identifier ("SIZE"), + definition, false); + + /* ??? For now, store the size as a multiple of the alignment in + bytes so that we can see the alignment from the tree. */ + TYPE_SIZE_UNIT (gnu_type) + = elaborate_expression_2 (TYPE_SIZE_UNIT (gnu_type), gnat_entity, + get_identifier ("SIZE_A_UNIT"), + definition, false, + TYPE_ALIGN (gnu_type)); + + /* ??? gnu_type may come from an existing type so the MULT_EXPR node + may not be marked by the call to create_type_decl below. */ + MARK_VISITED (TYPE_SIZE_UNIT (gnu_type)); + + if (TREE_CODE (gnu_type) == RECORD_TYPE) + { + tree variant_part = get_variant_part (gnu_type); + tree ada_size = TYPE_ADA_SIZE (gnu_type); + + if (variant_part) + { + tree union_type = TREE_TYPE (variant_part); + tree offset = DECL_FIELD_OFFSET (variant_part); + + /* If the position of the variant part is constant, subtract + it from the size of the type of the parent to get the new + size. This manual CSE reduces the data size. */ + if (TREE_CODE (offset) == INTEGER_CST) + { + tree bitpos = DECL_FIELD_BIT_OFFSET (variant_part); + TYPE_SIZE (union_type) + = size_binop (MINUS_EXPR, TYPE_SIZE (gnu_type), + bit_from_pos (offset, bitpos)); + TYPE_SIZE_UNIT (union_type) + = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (gnu_type), + byte_from_pos (offset, bitpos)); + } + else + { + TYPE_SIZE (union_type) + = elaborate_expression_1 (TYPE_SIZE (union_type), + gnat_entity, + get_identifier ("VSIZE"), + definition, false); + + /* ??? For now, store the size as a multiple of the + alignment in bytes so that we can see the alignment + from the tree. */ + TYPE_SIZE_UNIT (union_type) + = elaborate_expression_2 (TYPE_SIZE_UNIT (union_type), + gnat_entity, + get_identifier + ("VSIZE_A_UNIT"), + definition, false, + TYPE_ALIGN (union_type)); + + /* ??? For now, store the offset as a multiple of the + alignment in bytes so that we can see the alignment + from the tree. */ + DECL_FIELD_OFFSET (variant_part) + = elaborate_expression_2 (offset, + gnat_entity, + get_identifier ("VOFFSET"), + definition, false, + DECL_OFFSET_ALIGN + (variant_part)); + } + + DECL_SIZE (variant_part) = TYPE_SIZE (union_type); + DECL_SIZE_UNIT (variant_part) = TYPE_SIZE_UNIT (union_type); + } + + if (operand_equal_p (ada_size, size, 0)) + ada_size = TYPE_SIZE (gnu_type); + else + ada_size + = elaborate_expression_1 (ada_size, gnat_entity, + get_identifier ("RM_SIZE"), + definition, false); + SET_TYPE_ADA_SIZE (gnu_type, ada_size); + } + } + + /* If this is a record type or subtype, call elaborate_expression_1 on + any field position. Do this for both global and local types. + Skip any fields that we haven't made trees for to avoid problems with + class wide types. */ + if (IN (kind, Record_Kind)) + for (gnat_temp = First_Entity (gnat_entity); Present (gnat_temp); + gnat_temp = Next_Entity (gnat_temp)) + if (Ekind (gnat_temp) == E_Component && present_gnu_tree (gnat_temp)) + { + tree gnu_field = get_gnu_tree (gnat_temp); + + /* ??? For now, store the offset as a multiple of the alignment + in bytes so that we can see the alignment from the tree. */ + if (!CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (gnu_field))) + { + DECL_FIELD_OFFSET (gnu_field) + = elaborate_expression_2 (DECL_FIELD_OFFSET (gnu_field), + gnat_temp, + get_identifier ("OFFSET"), + definition, false, + DECL_OFFSET_ALIGN (gnu_field)); + + /* ??? The context of gnu_field is not necessarily gnu_type + so the MULT_EXPR node built above may not be marked by + the call to create_type_decl below. */ + if (global_bindings_p ()) + MARK_VISITED (DECL_FIELD_OFFSET (gnu_field)); + } + } + + if (Treat_As_Volatile (gnat_entity)) + gnu_type + = build_qualified_type (gnu_type, + TYPE_QUALS (gnu_type) | TYPE_QUAL_VOLATILE); + + if (Is_Atomic (gnat_entity)) + check_ok_for_atomic (gnu_type, gnat_entity, false); + + if (Present (Alignment_Clause (gnat_entity))) + TYPE_USER_ALIGN (gnu_type) = 1; + + if (Universal_Aliasing (gnat_entity)) + TYPE_UNIVERSAL_ALIASING_P (TYPE_MAIN_VARIANT (gnu_type)) = 1; + + if (!gnu_decl) + gnu_decl = create_type_decl (gnu_entity_name, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + else + { + TREE_TYPE (gnu_decl) = gnu_type; + TYPE_STUB_DECL (gnu_type) = gnu_decl; + } + } + + if (is_type && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl))) + { + gnu_type = TREE_TYPE (gnu_decl); + + /* If this is a derived type, relate its alias set to that of its parent + to avoid troubles when a call to an inherited primitive is inlined in + a context where a derived object is accessed. The inlined code works + on the parent view so the resulting code may access the same object + using both the parent and the derived alias sets, which thus have to + conflict. As the same issue arises with component references, the + parent alias set also has to conflict with composite types enclosing + derived components. For instance, if we have: + + type D is new T; + type R is record + Component : D; + end record; + + we want T to conflict with both D and R, in addition to R being a + superset of D by record/component construction. + + One way to achieve this is to perform an alias set copy from the + parent to the derived type. This is not quite appropriate, though, + as we don't want separate derived types to conflict with each other: + + type I1 is new Integer; + type I2 is new Integer; + + We want I1 and I2 to both conflict with Integer but we do not want + I1 to conflict with I2, and an alias set copy on derivation would + have that effect. + + The option chosen is to make the alias set of the derived type a + superset of that of its parent type. It trivially fulfills the + simple requirement for the Integer derivation example above, and + the component case as well by superset transitivity: + + superset superset + R ----------> D ----------> T + + However, for composite types, conversions between derived types are + translated into VIEW_CONVERT_EXPRs so a sequence like: + + type Comp1 is new Comp; + type Comp2 is new Comp; + procedure Proc (C : Comp1); + + C : Comp2; + Proc (Comp1 (C)); + + is translated into: + + C : Comp2; + Proc ((Comp1 &) &VIEW_CONVERT_EXPR (C)); + + and gimplified into: + + C : Comp2; + Comp1 *C.0; + C.0 = (Comp1 *) &C; + Proc (C.0); + + i.e. generates code involving type punning. Therefore, Comp1 needs + to conflict with Comp2 and an alias set copy is required. + + The language rules ensure the parent type is already frozen here. */ + if (Is_Derived_Type (gnat_entity)) + { + tree gnu_parent_type = gnat_to_gnu_type (Etype (gnat_entity)); + relate_alias_sets (gnu_type, gnu_parent_type, + Is_Composite_Type (gnat_entity) + ? ALIAS_SET_COPY : ALIAS_SET_SUPERSET); + } + + /* Back-annotate the Alignment of the type if not already in the + tree. Likewise for sizes. */ + if (Unknown_Alignment (gnat_entity)) + { + unsigned int double_align, align; + bool is_capped_double, align_clause; + + /* If the default alignment of "double" or larger scalar types is + specifically capped and this is not an array with an alignment + clause on the component type, return the cap. */ + if ((double_align = double_float_alignment) > 0) + is_capped_double + = is_double_float_or_array (gnat_entity, &align_clause); + else if ((double_align = double_scalar_alignment) > 0) + is_capped_double + = is_double_scalar_or_array (gnat_entity, &align_clause); + else + is_capped_double = align_clause = false; + + if (is_capped_double && !align_clause) + align = double_align; + else + align = TYPE_ALIGN (gnu_type) / BITS_PER_UNIT; + + Set_Alignment (gnat_entity, UI_From_Int (align)); + } + + if (Unknown_Esize (gnat_entity) && TYPE_SIZE (gnu_type)) + { + tree gnu_size = TYPE_SIZE (gnu_type); + + /* If the size is self-referential, annotate the maximum value. */ + if (CONTAINS_PLACEHOLDER_P (gnu_size)) + gnu_size = max_size (gnu_size, true); + + if (type_annotate_only && Is_Tagged_Type (gnat_entity)) + { + /* In this mode, the tag and the parent components are not + generated by the front-end so the sizes must be adjusted. */ + tree pointer_size = bitsize_int (POINTER_SIZE), offset; + Uint uint_size; + + if (Is_Derived_Type (gnat_entity)) + { + offset = UI_To_gnu (Esize (Etype (Base_Type (gnat_entity))), + bitsizetype); + Set_Alignment (gnat_entity, + Alignment (Etype (Base_Type (gnat_entity)))); + } + else + offset = pointer_size; + + gnu_size = size_binop (PLUS_EXPR, gnu_size, offset); + gnu_size = size_binop (MULT_EXPR, pointer_size, + size_binop (CEIL_DIV_EXPR, + gnu_size, + pointer_size)); + uint_size = annotate_value (gnu_size); + Set_Esize (gnat_entity, uint_size); + Set_RM_Size (gnat_entity, uint_size); + } + else + Set_Esize (gnat_entity, annotate_value (gnu_size)); + } + + if (Unknown_RM_Size (gnat_entity) && rm_size (gnu_type)) + Set_RM_Size (gnat_entity, annotate_value (rm_size (gnu_type))); + } + + /* If we really have a ..._DECL node, set a couple of flags on it. But we + cannot do that if we are reusing the ..._DECL node made for a renamed + object, since the predicates don't apply to it but to GNAT_ENTITY. */ + if (DECL_P (gnu_decl) && !(Present (Renamed_Object (gnat_entity)) && saved)) + { + if (!Comes_From_Source (gnat_entity)) + DECL_ARTIFICIAL (gnu_decl) = 1; + + if (!debug_info_p && TREE_CODE (gnu_decl) != FUNCTION_DECL) + DECL_IGNORED_P (gnu_decl) = 1; + } + + /* If we haven't already, associate the ..._DECL node that we just made with + the input GNAT entity node. */ + if (!saved) + save_gnu_tree (gnat_entity, gnu_decl, false); + + /* If this is an enumeration or floating-point type, we were not able to set + the bounds since they refer to the type. These are always static. */ + if ((kind == E_Enumeration_Type && Present (First_Literal (gnat_entity))) + || (kind == E_Floating_Point_Type && !Vax_Float (gnat_entity))) + { + tree gnu_scalar_type = gnu_type; + tree gnu_low_bound, gnu_high_bound; + + /* If this is a padded type, we need to use the underlying type. */ + if (TYPE_IS_PADDING_P (gnu_scalar_type)) + gnu_scalar_type = TREE_TYPE (TYPE_FIELDS (gnu_scalar_type)); + + /* If this is a floating point type and we haven't set a floating + point type yet, use this in the evaluation of the bounds. */ + if (!longest_float_type_node && kind == E_Floating_Point_Type) + longest_float_type_node = gnu_scalar_type; + + gnu_low_bound = gnat_to_gnu (Type_Low_Bound (gnat_entity)); + gnu_high_bound = gnat_to_gnu (Type_High_Bound (gnat_entity)); + + if (kind == E_Enumeration_Type) + { + /* Enumeration types have specific RM bounds. */ + SET_TYPE_RM_MIN_VALUE (gnu_scalar_type, gnu_low_bound); + SET_TYPE_RM_MAX_VALUE (gnu_scalar_type, gnu_high_bound); + + /* Write full debugging information. Since this has both a + typedef and a tag, avoid outputting the name twice. */ + DECL_ARTIFICIAL (gnu_decl) = 1; + rest_of_type_decl_compilation (gnu_decl); + } + + else + { + /* Floating-point types don't have specific RM bounds. */ + TYPE_GCC_MIN_VALUE (gnu_scalar_type) = gnu_low_bound; + TYPE_GCC_MAX_VALUE (gnu_scalar_type) = gnu_high_bound; + } + } + + /* If we deferred processing of incomplete types, re-enable it. If there + were no other disables and we have some to process, do so. */ + if (this_deferred && --defer_incomplete_level == 0) + { + if (defer_incomplete_list) + { + struct incomplete *incp, *next; + + /* We are back to level 0 for the deferring of incomplete types. + But processing these incomplete types below may itself require + deferring, so preserve what we have and restart from scratch. */ + incp = defer_incomplete_list; + defer_incomplete_list = NULL; + + /* For finalization, however, all types must be complete so we + cannot do the same because deferred incomplete types may end up + referencing each other. Process them all recursively first. */ + defer_finalize_level++; + + for (; incp; incp = next) + { + next = incp->next; + + if (incp->old_type) + update_pointer_to (TYPE_MAIN_VARIANT (incp->old_type), + gnat_to_gnu_type (incp->full_type)); + free (incp); + } + + defer_finalize_level--; + } + + /* All the deferred incomplete types have been processed so we can + now proceed with the finalization of the deferred types. */ + if (defer_finalize_level == 0 && defer_finalize_list) + { + unsigned int i; + tree t; + + FOR_EACH_VEC_ELT (tree, defer_finalize_list, i, t) + rest_of_type_decl_compilation_no_defer (t); + + VEC_free (tree, heap, defer_finalize_list); + } + } + + /* If we are not defining this type, see if it's in the incomplete list. + If so, handle that list entry now. */ + else if (!definition) + { + struct incomplete *incp; + + for (incp = defer_incomplete_list; incp; incp = incp->next) + if (incp->old_type && incp->full_type == gnat_entity) + { + update_pointer_to (TYPE_MAIN_VARIANT (incp->old_type), + TREE_TYPE (gnu_decl)); + incp->old_type = NULL_TREE; + } + } + + if (this_global) + force_global--; + + /* If this is a packed array type whose original array type is itself + an Itype without freeze node, make sure the latter is processed. */ + if (Is_Packed_Array_Type (gnat_entity) + && Is_Itype (Original_Array_Type (gnat_entity)) + && No (Freeze_Node (Original_Array_Type (gnat_entity))) + && !present_gnu_tree (Original_Array_Type (gnat_entity))) + gnat_to_gnu_entity (Original_Array_Type (gnat_entity), NULL_TREE, 0); + + return gnu_decl; +} + +/* Similar, but if the returned value is a COMPONENT_REF, return the + FIELD_DECL. */ + +tree +gnat_to_gnu_field_decl (Entity_Id gnat_entity) +{ + tree gnu_field = gnat_to_gnu_entity (gnat_entity, NULL_TREE, 0); + + if (TREE_CODE (gnu_field) == COMPONENT_REF) + gnu_field = TREE_OPERAND (gnu_field, 1); + + return gnu_field; +} + +/* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return + the GCC type corresponding to that entity. */ + +tree +gnat_to_gnu_type (Entity_Id gnat_entity) +{ + tree gnu_decl; + + /* The back end never attempts to annotate generic types. */ + if (Is_Generic_Type (gnat_entity) && type_annotate_only) + return void_type_node; + + gnu_decl = gnat_to_gnu_entity (gnat_entity, NULL_TREE, 0); + gcc_assert (TREE_CODE (gnu_decl) == TYPE_DECL); + + return TREE_TYPE (gnu_decl); +} + +/* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return + the unpadded version of the GCC type corresponding to that entity. */ + +tree +get_unpadded_type (Entity_Id gnat_entity) +{ + tree type = gnat_to_gnu_type (gnat_entity); + + if (TYPE_IS_PADDING_P (type)) + type = TREE_TYPE (TYPE_FIELDS (type)); + + return type; +} + +/* Wrap up compilation of DECL, a TYPE_DECL, possibly deferring it. + Every TYPE_DECL generated for a type definition must be passed + to this function once everything else has been done for it. */ + +void +rest_of_type_decl_compilation (tree decl) +{ + /* We need to defer finalizing the type if incomplete types + are being deferred or if they are being processed. */ + if (defer_incomplete_level != 0 || defer_finalize_level != 0) + VEC_safe_push (tree, heap, defer_finalize_list, decl); + else + rest_of_type_decl_compilation_no_defer (decl); +} + +/* Same as above but without deferring the compilation. This + function should not be invoked directly on a TYPE_DECL. */ + +static void +rest_of_type_decl_compilation_no_defer (tree decl) +{ + const int toplev = global_bindings_p (); + tree t = TREE_TYPE (decl); + + rest_of_decl_compilation (decl, toplev, 0); + + /* Now process all the variants. This is needed for STABS. */ + for (t = TYPE_MAIN_VARIANT (t); t; t = TYPE_NEXT_VARIANT (t)) + { + if (t == TREE_TYPE (decl)) + continue; + + if (!TYPE_STUB_DECL (t)) + TYPE_STUB_DECL (t) = create_type_stub_decl (DECL_NAME (decl), t); + + rest_of_type_compilation (t, toplev); + } +} + +/* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST, + finish constructing the record type as a fat pointer type. */ + +static void +finish_fat_pointer_type (tree record_type, tree field_list) +{ + /* Make sure we can put it into a register. */ + TYPE_ALIGN (record_type) = MIN (BIGGEST_ALIGNMENT, 2 * POINTER_SIZE); + + /* Show what it really is. */ + TYPE_FAT_POINTER_P (record_type) = 1; + + /* Do not emit debug info for it since the types of its fields may still be + incomplete at this point. */ + finish_record_type (record_type, field_list, 0, false); + + /* Force type_contains_placeholder_p to return true on it. Although the + PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer + type but the representation of the unconstrained array. */ + TYPE_CONTAINS_PLACEHOLDER_INTERNAL (record_type) = 2; +} + +/* Finalize any From_With_Type incomplete types. We do this after processing + our compilation unit and after processing its spec, if this is a body. */ + +void +finalize_from_with_types (void) +{ + struct incomplete *incp = defer_limited_with; + struct incomplete *next; + + defer_limited_with = 0; + for (; incp; incp = next) + { + next = incp->next; + + if (incp->old_type != 0) + update_pointer_to (TYPE_MAIN_VARIANT (incp->old_type), + gnat_to_gnu_type (incp->full_type)); + free (incp); + } +} + +/* Return the equivalent type to be used for GNAT_ENTITY, if it's a + kind of type (such E_Task_Type) that has a different type which Gigi + uses for its representation. If the type does not have a special type + for its representation, return GNAT_ENTITY. If a type is supposed to + exist, but does not, abort unless annotating types, in which case + return Empty. If GNAT_ENTITY is Empty, return Empty. */ + +Entity_Id +Gigi_Equivalent_Type (Entity_Id gnat_entity) +{ + Entity_Id gnat_equiv = gnat_entity; + + if (No (gnat_entity)) + return gnat_entity; + + switch (Ekind (gnat_entity)) + { + case E_Class_Wide_Subtype: + if (Present (Equivalent_Type (gnat_entity))) + gnat_equiv = Equivalent_Type (gnat_entity); + break; + + case E_Access_Protected_Subprogram_Type: + case E_Anonymous_Access_Protected_Subprogram_Type: + gnat_equiv = Equivalent_Type (gnat_entity); + break; + + case E_Class_Wide_Type: + gnat_equiv = Root_Type (gnat_entity); + break; + + case E_Task_Type: + case E_Task_Subtype: + case E_Protected_Type: + case E_Protected_Subtype: + gnat_equiv = Corresponding_Record_Type (gnat_entity); + break; + + default: + break; + } + + gcc_assert (Present (gnat_equiv) || type_annotate_only); + return gnat_equiv; +} + +/* Return a GCC tree for a type corresponding to the component type of the + array type or subtype GNAT_ARRAY. DEFINITION is true if this component + is for an array being defined. DEBUG_INFO_P is true if we need to write + debug information for other types that we may create in the process. */ + +static tree +gnat_to_gnu_component_type (Entity_Id gnat_array, bool definition, + bool debug_info_p) +{ + tree gnu_type = gnat_to_gnu_type (Component_Type (gnat_array)); + tree gnu_comp_size; + + /* Try to get a smaller form of the component if needed. */ + if ((Is_Packed (gnat_array) + || Has_Component_Size_Clause (gnat_array)) + && !Is_Bit_Packed_Array (gnat_array) + && !Has_Aliased_Components (gnat_array) + && !Strict_Alignment (Component_Type (gnat_array)) + && TREE_CODE (gnu_type) == RECORD_TYPE + && !TYPE_FAT_POINTER_P (gnu_type) + && host_integerp (TYPE_SIZE (gnu_type), 1)) + gnu_type = make_packable_type (gnu_type, false); + + if (Has_Atomic_Components (gnat_array)) + check_ok_for_atomic (gnu_type, gnat_array, true); + + /* Get and validate any specified Component_Size. */ + gnu_comp_size + = validate_size (Component_Size (gnat_array), gnu_type, gnat_array, + Is_Bit_Packed_Array (gnat_array) ? TYPE_DECL : VAR_DECL, + true, Has_Component_Size_Clause (gnat_array)); + + /* If the array has aliased components and the component size can be zero, + force at least unit size to ensure that the components have distinct + addresses. */ + if (!gnu_comp_size + && Has_Aliased_Components (gnat_array) + && (integer_zerop (TYPE_SIZE (gnu_type)) + || (TREE_CODE (gnu_type) == ARRAY_TYPE + && !TREE_CONSTANT (TYPE_SIZE (gnu_type))))) + gnu_comp_size + = size_binop (MAX_EXPR, TYPE_SIZE (gnu_type), bitsize_unit_node); + + /* If the component type is a RECORD_TYPE that has a self-referential size, + then use the maximum size for the component size. */ + if (!gnu_comp_size + && TREE_CODE (gnu_type) == RECORD_TYPE + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))) + gnu_comp_size = max_size (TYPE_SIZE (gnu_type), true); + + /* Honor the component size. This is not needed for bit-packed arrays. */ + if (gnu_comp_size && !Is_Bit_Packed_Array (gnat_array)) + { + tree orig_type = gnu_type; + unsigned int max_align; + + /* If an alignment is specified, use it as a cap on the component type + so that it can be honored for the whole type. But ignore it for the + original type of packed array types. */ + if (No (Packed_Array_Type (gnat_array)) && Known_Alignment (gnat_array)) + max_align = validate_alignment (Alignment (gnat_array), gnat_array, 0); + else + max_align = 0; + + gnu_type = make_type_from_size (gnu_type, gnu_comp_size, false); + if (max_align > 0 && TYPE_ALIGN (gnu_type) > max_align) + gnu_type = orig_type; + else + orig_type = gnu_type; + + gnu_type = maybe_pad_type (gnu_type, gnu_comp_size, 0, gnat_array, + true, false, definition, true); + + /* If a padding record was made, declare it now since it will never be + declared otherwise. This is necessary to ensure that its subtrees + are properly marked. */ + if (gnu_type != orig_type && !DECL_P (TYPE_NAME (gnu_type))) + create_type_decl (TYPE_NAME (gnu_type), gnu_type, NULL, true, + debug_info_p, gnat_array); + } + + if (Has_Volatile_Components (Base_Type (gnat_array))) + gnu_type + = build_qualified_type (gnu_type, + TYPE_QUALS (gnu_type) | TYPE_QUAL_VOLATILE); + + return gnu_type; +} + +/* Return a GCC tree for a parameter corresponding to GNAT_PARAM and + using MECH as its passing mechanism, to be placed in the parameter + list built for GNAT_SUBPROG. Assume a foreign convention for the + latter if FOREIGN is true. Also set CICO to true if the parameter + must use the copy-in copy-out implementation mechanism. + + The returned tree is a PARM_DECL, except for those cases where no + parameter needs to be actually passed to the subprogram; the type + of this "shadow" parameter is then returned instead. */ + +static tree +gnat_to_gnu_param (Entity_Id gnat_param, Mechanism_Type mech, + Entity_Id gnat_subprog, bool foreign, bool *cico) +{ + tree gnu_param_name = get_entity_name (gnat_param); + tree gnu_param_type = gnat_to_gnu_type (Etype (gnat_param)); + tree gnu_param_type_alt = NULL_TREE; + bool in_param = (Ekind (gnat_param) == E_In_Parameter); + /* The parameter can be indirectly modified if its address is taken. */ + bool ro_param = in_param && !Address_Taken (gnat_param); + bool by_return = false, by_component_ptr = false; + bool by_ref = false, by_double_ref = false; + tree gnu_param; + + /* Copy-return is used only for the first parameter of a valued procedure. + It's a copy mechanism for which a parameter is never allocated. */ + if (mech == By_Copy_Return) + { + gcc_assert (Ekind (gnat_param) == E_Out_Parameter); + mech = By_Copy; + by_return = true; + } + + /* If this is either a foreign function or if the underlying type won't + be passed by reference, strip off possible padding type. */ + if (TYPE_IS_PADDING_P (gnu_param_type)) + { + tree unpadded_type = TREE_TYPE (TYPE_FIELDS (gnu_param_type)); + + if (mech == By_Reference + || foreign + || (!must_pass_by_ref (unpadded_type) + && (mech == By_Copy || !default_pass_by_ref (unpadded_type)))) + gnu_param_type = unpadded_type; + } + + /* If this is a read-only parameter, make a variant of the type that is + read-only. ??? However, if this is an unconstrained array, that type + can be very complex, so skip it for now. Likewise for any other + self-referential type. */ + if (ro_param + && TREE_CODE (gnu_param_type) != UNCONSTRAINED_ARRAY_TYPE + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_param_type))) + gnu_param_type = build_qualified_type (gnu_param_type, + (TYPE_QUALS (gnu_param_type) + | TYPE_QUAL_CONST)); + + /* For foreign conventions, pass arrays as pointers to the element type. + First check for unconstrained array and get the underlying array. */ + if (foreign && TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_param_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_param_type)))); + + /* For GCC builtins, pass Address integer types as (void *) */ + if (Convention (gnat_subprog) == Convention_Intrinsic + && Present (Interface_Name (gnat_subprog)) + && Is_Descendent_Of_Address (Etype (gnat_param))) + gnu_param_type = ptr_void_type_node; + + /* VMS descriptors are themselves passed by reference. */ + if (mech == By_Short_Descriptor || + (mech == By_Descriptor && TARGET_ABI_OPEN_VMS && !TARGET_MALLOC64)) + gnu_param_type + = build_pointer_type (build_vms_descriptor32 (gnu_param_type, + Mechanism (gnat_param), + gnat_subprog)); + else if (mech == By_Descriptor) + { + /* Build both a 32-bit and 64-bit descriptor, one of which will be + chosen in fill_vms_descriptor. */ + gnu_param_type_alt + = build_pointer_type (build_vms_descriptor32 (gnu_param_type, + Mechanism (gnat_param), + gnat_subprog)); + gnu_param_type + = build_pointer_type (build_vms_descriptor (gnu_param_type, + Mechanism (gnat_param), + gnat_subprog)); + } + + /* Arrays are passed as pointers to element type for foreign conventions. */ + else if (foreign + && mech != By_Copy + && TREE_CODE (gnu_param_type) == ARRAY_TYPE) + { + /* Strip off any multi-dimensional entries, then strip + off the last array to get the component type. */ + while (TREE_CODE (TREE_TYPE (gnu_param_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_param_type))) + gnu_param_type = TREE_TYPE (gnu_param_type); + + by_component_ptr = true; + gnu_param_type = TREE_TYPE (gnu_param_type); + + if (ro_param) + gnu_param_type = build_qualified_type (gnu_param_type, + (TYPE_QUALS (gnu_param_type) + | TYPE_QUAL_CONST)); + + gnu_param_type = build_pointer_type (gnu_param_type); + } + + /* Fat pointers are passed as thin pointers for foreign conventions. */ + else if (foreign && TYPE_IS_FAT_POINTER_P (gnu_param_type)) + gnu_param_type + = make_type_from_size (gnu_param_type, size_int (POINTER_SIZE), 0); + + /* If we must pass or were requested to pass by reference, do so. + If we were requested to pass by copy, do so. + Otherwise, for foreign conventions, pass In Out or Out parameters + or aggregates by reference. For COBOL and Fortran, pass all + integer and FP types that way too. For Convention Ada, use + the standard Ada default. */ + else if (must_pass_by_ref (gnu_param_type) + || mech == By_Reference + || (mech != By_Copy + && ((foreign + && (!in_param || AGGREGATE_TYPE_P (gnu_param_type))) + || (foreign + && (Convention (gnat_subprog) == Convention_Fortran + || Convention (gnat_subprog) == Convention_COBOL) + && (INTEGRAL_TYPE_P (gnu_param_type) + || FLOAT_TYPE_P (gnu_param_type))) + || (!foreign + && default_pass_by_ref (gnu_param_type))))) + { + gnu_param_type = build_reference_type (gnu_param_type); + by_ref = true; + + /* In some ABIs, e.g. SPARC 32-bit, fat pointer types are themselves + passed by reference. Pass them by explicit reference, this will + generate more debuggable code at -O0. */ + if (TYPE_IS_FAT_POINTER_P (gnu_param_type) + && targetm.calls.pass_by_reference (NULL, + TYPE_MODE (gnu_param_type), + gnu_param_type, + true)) + { + gnu_param_type = build_reference_type (gnu_param_type); + by_double_ref = true; + } + } + + /* Pass In Out or Out parameters using copy-in copy-out mechanism. */ + else if (!in_param) + *cico = true; + + if (mech == By_Copy && (by_ref || by_component_ptr)) + post_error ("?cannot pass & by copy", gnat_param); + + /* If this is an Out parameter that isn't passed by reference and isn't + a pointer or aggregate, we don't make a PARM_DECL for it. Instead, + it will be a VAR_DECL created when we process the procedure, so just + return its type. For the special parameter of a valued procedure, + never pass it in. + + An exception is made to cover the RM-6.4.1 rule requiring "by copy" + Out parameters with discriminants or implicit initial values to be + handled like In Out parameters. These type are normally built as + aggregates, hence passed by reference, except for some packed arrays + which end up encoded in special integer types. + + The exception we need to make is then for packed arrays of records + with discriminants or implicit initial values. We have no light/easy + way to check for the latter case, so we merely check for packed arrays + of records. This may lead to useless copy-in operations, but in very + rare cases only, as these would be exceptions in a set of already + exceptional situations. */ + if (Ekind (gnat_param) == E_Out_Parameter + && !by_ref + && (by_return + || (mech != By_Descriptor + && mech != By_Short_Descriptor + && !POINTER_TYPE_P (gnu_param_type) + && !AGGREGATE_TYPE_P (gnu_param_type))) + && !(Is_Array_Type (Etype (gnat_param)) + && Is_Packed (Etype (gnat_param)) + && Is_Composite_Type (Component_Type (Etype (gnat_param))))) + return gnu_param_type; + + gnu_param = create_param_decl (gnu_param_name, gnu_param_type, + ro_param || by_ref || by_component_ptr); + DECL_BY_REF_P (gnu_param) = by_ref; + DECL_BY_DOUBLE_REF_P (gnu_param) = by_double_ref; + DECL_BY_COMPONENT_PTR_P (gnu_param) = by_component_ptr; + DECL_BY_DESCRIPTOR_P (gnu_param) = (mech == By_Descriptor || + mech == By_Short_Descriptor); + DECL_POINTS_TO_READONLY_P (gnu_param) + = (ro_param && (by_ref || by_component_ptr)); + + /* Save the alternate descriptor type, if any. */ + if (gnu_param_type_alt) + SET_DECL_PARM_ALT_TYPE (gnu_param, gnu_param_type_alt); + + /* If no Mechanism was specified, indicate what we're using, then + back-annotate it. */ + if (mech == Default) + mech = (by_ref || by_component_ptr) ? By_Reference : By_Copy; + + Set_Mechanism (gnat_param, mech); + return gnu_param; +} + +/* Return true if DISCR1 and DISCR2 represent the same discriminant. */ + +static bool +same_discriminant_p (Entity_Id discr1, Entity_Id discr2) +{ + while (Present (Corresponding_Discriminant (discr1))) + discr1 = Corresponding_Discriminant (discr1); + + while (Present (Corresponding_Discriminant (discr2))) + discr2 = Corresponding_Discriminant (discr2); + + return + Original_Record_Component (discr1) == Original_Record_Component (discr2); +} + +/* Return true if the array type GNU_TYPE, which represents a dimension of + GNAT_TYPE, has a non-aliased component in the back-end sense. */ + +static bool +array_type_has_nonaliased_component (tree gnu_type, Entity_Id gnat_type) +{ + /* If the array type is not the innermost dimension of the GNAT type, + then it has a non-aliased component. */ + if (TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type))) + return true; + + /* If the array type has an aliased component in the front-end sense, + then it also has an aliased component in the back-end sense. */ + if (Has_Aliased_Components (gnat_type)) + return false; + + /* If this is a derived type, then it has a non-aliased component if + and only if its parent type also has one. */ + if (Is_Derived_Type (gnat_type)) + { + tree gnu_parent_type = gnat_to_gnu_type (Etype (gnat_type)); + int index; + if (TREE_CODE (gnu_parent_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_parent_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_parent_type)))); + for (index = Number_Dimensions (gnat_type) - 1; index > 0; index--) + gnu_parent_type = TREE_TYPE (gnu_parent_type); + return TYPE_NONALIASED_COMPONENT (gnu_parent_type); + } + + /* Otherwise, rely exclusively on properties of the element type. */ + return type_for_nonaliased_component_p (TREE_TYPE (gnu_type)); +} + +/* Return true if GNAT_ADDRESS is a value known at compile-time. */ + +static bool +compile_time_known_address_p (Node_Id gnat_address) +{ + /* Catch System'To_Address. */ + if (Nkind (gnat_address) == N_Unchecked_Type_Conversion) + gnat_address = Expression (gnat_address); + + return Compile_Time_Known_Value (gnat_address); +} + +/* Return true if GNAT_RANGE, a N_Range node, cannot be superflat, i.e. if the + inequality HB >= LB-1 is true. LB and HB are the low and high bounds. */ + +static bool +cannot_be_superflat_p (Node_Id gnat_range) +{ + Node_Id gnat_lb = Low_Bound (gnat_range), gnat_hb = High_Bound (gnat_range); + Node_Id scalar_range; + tree gnu_lb, gnu_hb, gnu_lb_minus_one; + + /* If the low bound is not constant, try to find an upper bound. */ + while (Nkind (gnat_lb) != N_Integer_Literal + && (Ekind (Etype (gnat_lb)) == E_Signed_Integer_Subtype + || Ekind (Etype (gnat_lb)) == E_Modular_Integer_Subtype) + && (scalar_range = Scalar_Range (Etype (gnat_lb))) + && (Nkind (scalar_range) == N_Signed_Integer_Type_Definition + || Nkind (scalar_range) == N_Range)) + gnat_lb = High_Bound (scalar_range); + + /* If the high bound is not constant, try to find a lower bound. */ + while (Nkind (gnat_hb) != N_Integer_Literal + && (Ekind (Etype (gnat_hb)) == E_Signed_Integer_Subtype + || Ekind (Etype (gnat_hb)) == E_Modular_Integer_Subtype) + && (scalar_range = Scalar_Range (Etype (gnat_hb))) + && (Nkind (scalar_range) == N_Signed_Integer_Type_Definition + || Nkind (scalar_range) == N_Range)) + gnat_hb = Low_Bound (scalar_range); + + /* If we have failed to find constant bounds, punt. */ + if (Nkind (gnat_lb) != N_Integer_Literal + || Nkind (gnat_hb) != N_Integer_Literal) + return false; + + /* We need at least a signed 64-bit type to catch most cases. */ + gnu_lb = UI_To_gnu (Intval (gnat_lb), sbitsizetype); + gnu_hb = UI_To_gnu (Intval (gnat_hb), sbitsizetype); + if (TREE_OVERFLOW (gnu_lb) || TREE_OVERFLOW (gnu_hb)) + return false; + + /* If the low bound is the smallest integer, nothing can be smaller. */ + gnu_lb_minus_one = size_binop (MINUS_EXPR, gnu_lb, sbitsize_one_node); + if (TREE_OVERFLOW (gnu_lb_minus_one)) + return true; + + return !tree_int_cst_lt (gnu_hb, gnu_lb_minus_one); +} + +/* Return true if GNU_EXPR is (essentially) the address of a CONSTRUCTOR. */ + +static bool +constructor_address_p (tree gnu_expr) +{ + while (TREE_CODE (gnu_expr) == NOP_EXPR + || TREE_CODE (gnu_expr) == CONVERT_EXPR + || TREE_CODE (gnu_expr) == NON_LVALUE_EXPR) + gnu_expr = TREE_OPERAND (gnu_expr, 0); + + return (TREE_CODE (gnu_expr) == ADDR_EXPR + && TREE_CODE (TREE_OPERAND (gnu_expr, 0)) == CONSTRUCTOR); +} + +/* Given GNAT_ENTITY, elaborate all expressions that are required to + be elaborated at the point of its definition, but do nothing else. */ + +void +elaborate_entity (Entity_Id gnat_entity) +{ + switch (Ekind (gnat_entity)) + { + case E_Signed_Integer_Subtype: + case E_Modular_Integer_Subtype: + case E_Enumeration_Subtype: + case E_Ordinary_Fixed_Point_Subtype: + case E_Decimal_Fixed_Point_Subtype: + case E_Floating_Point_Subtype: + { + Node_Id gnat_lb = Type_Low_Bound (gnat_entity); + Node_Id gnat_hb = Type_High_Bound (gnat_entity); + + /* ??? Tests to avoid Constraint_Error in static expressions + are needed until after the front stops generating bogus + conversions on bounds of real types. */ + if (!Raises_Constraint_Error (gnat_lb)) + elaborate_expression (gnat_lb, gnat_entity, get_identifier ("L"), + true, false, Needs_Debug_Info (gnat_entity)); + if (!Raises_Constraint_Error (gnat_hb)) + elaborate_expression (gnat_hb, gnat_entity, get_identifier ("U"), + true, false, Needs_Debug_Info (gnat_entity)); + break; + } + + case E_Record_Type: + { + Node_Id full_definition = Declaration_Node (gnat_entity); + Node_Id record_definition = Type_Definition (full_definition); + + /* If this is a record extension, go a level further to find the + record definition. */ + if (Nkind (record_definition) == N_Derived_Type_Definition) + record_definition = Record_Extension_Part (record_definition); + } + break; + + case E_Record_Subtype: + case E_Private_Subtype: + case E_Limited_Private_Subtype: + case E_Record_Subtype_With_Private: + if (Is_Constrained (gnat_entity) + && Has_Discriminants (gnat_entity) + && Present (Discriminant_Constraint (gnat_entity))) + { + Node_Id gnat_discriminant_expr; + Entity_Id gnat_field; + + for (gnat_field + = First_Discriminant (Implementation_Base_Type (gnat_entity)), + gnat_discriminant_expr + = First_Elmt (Discriminant_Constraint (gnat_entity)); + Present (gnat_field); + gnat_field = Next_Discriminant (gnat_field), + gnat_discriminant_expr = Next_Elmt (gnat_discriminant_expr)) + /* ??? For now, ignore access discriminants. */ + if (!Is_Access_Type (Etype (Node (gnat_discriminant_expr)))) + elaborate_expression (Node (gnat_discriminant_expr), + gnat_entity, get_entity_name (gnat_field), + true, false, false); + } + break; + + } +} + +/* Mark GNAT_ENTITY as going out of scope at this point. Recursively mark + any entities on its entity chain similarly. */ + +void +mark_out_of_scope (Entity_Id gnat_entity) +{ + Entity_Id gnat_sub_entity; + unsigned int kind = Ekind (gnat_entity); + + /* If this has an entity list, process all in the list. */ + if (IN (kind, Class_Wide_Kind) || IN (kind, Concurrent_Kind) + || IN (kind, Private_Kind) + || kind == E_Block || kind == E_Entry || kind == E_Entry_Family + || kind == E_Function || kind == E_Generic_Function + || kind == E_Generic_Package || kind == E_Generic_Procedure + || kind == E_Loop || kind == E_Operator || kind == E_Package + || kind == E_Package_Body || kind == E_Procedure + || kind == E_Record_Type || kind == E_Record_Subtype + || kind == E_Subprogram_Body || kind == E_Subprogram_Type) + for (gnat_sub_entity = First_Entity (gnat_entity); + Present (gnat_sub_entity); + gnat_sub_entity = Next_Entity (gnat_sub_entity)) + if (Scope (gnat_sub_entity) == gnat_entity + && gnat_sub_entity != gnat_entity) + mark_out_of_scope (gnat_sub_entity); + + /* Now clear this if it has been defined, but only do so if it isn't + a subprogram or parameter. We could refine this, but it isn't + worth it. If this is statically allocated, it is supposed to + hang around out of cope. */ + if (present_gnu_tree (gnat_entity) && !Is_Statically_Allocated (gnat_entity) + && kind != E_Procedure && kind != E_Function && !IN (kind, Formal_Kind)) + { + save_gnu_tree (gnat_entity, NULL_TREE, true); + save_gnu_tree (gnat_entity, error_mark_node, true); + } +} + +/* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP. + If this is a multi-dimensional array type, do this recursively. + + OP may be + - ALIAS_SET_COPY: the new set is made a copy of the old one. + - ALIAS_SET_SUPERSET: the new set is made a superset of the old one. + - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */ + +static void +relate_alias_sets (tree gnu_new_type, tree gnu_old_type, enum alias_set_op op) +{ + /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case + of a one-dimensional array, since the padding has the same alias set + as the field type, but if it's a multi-dimensional array, we need to + see the inner types. */ + while (TREE_CODE (gnu_old_type) == RECORD_TYPE + && (TYPE_JUSTIFIED_MODULAR_P (gnu_old_type) + || TYPE_PADDING_P (gnu_old_type))) + gnu_old_type = TREE_TYPE (TYPE_FIELDS (gnu_old_type)); + + /* Unconstrained array types are deemed incomplete and would thus be given + alias set 0. Retrieve the underlying array type. */ + if (TREE_CODE (gnu_old_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_old_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_old_type)))); + if (TREE_CODE (gnu_new_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_new_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_new_type)))); + + if (TREE_CODE (gnu_new_type) == ARRAY_TYPE + && TREE_CODE (TREE_TYPE (gnu_new_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_new_type))) + relate_alias_sets (TREE_TYPE (gnu_new_type), TREE_TYPE (gnu_old_type), op); + + switch (op) + { + case ALIAS_SET_COPY: + /* The alias set shouldn't be copied between array types with different + aliasing settings because this can break the aliasing relationship + between the array type and its element type. */ +#ifndef ENABLE_CHECKING + if (flag_strict_aliasing) +#endif + gcc_assert (!(TREE_CODE (gnu_new_type) == ARRAY_TYPE + && TREE_CODE (gnu_old_type) == ARRAY_TYPE + && TYPE_NONALIASED_COMPONENT (gnu_new_type) + != TYPE_NONALIASED_COMPONENT (gnu_old_type))); + + TYPE_ALIAS_SET (gnu_new_type) = get_alias_set (gnu_old_type); + break; + + case ALIAS_SET_SUBSET: + case ALIAS_SET_SUPERSET: + { + alias_set_type old_set = get_alias_set (gnu_old_type); + alias_set_type new_set = get_alias_set (gnu_new_type); + + /* Do nothing if the alias sets conflict. This ensures that we + never call record_alias_subset several times for the same pair + or at all for alias set 0. */ + if (!alias_sets_conflict_p (old_set, new_set)) + { + if (op == ALIAS_SET_SUBSET) + record_alias_subset (old_set, new_set); + else + record_alias_subset (new_set, old_set); + } + } + break; + + default: + gcc_unreachable (); + } + + record_component_aliases (gnu_new_type); +} + +/* Return true if the size represented by GNU_SIZE can be handled by an + allocation. If STATIC_P is true, consider only what can be done with a + static allocation. */ + +static bool +allocatable_size_p (tree gnu_size, bool static_p) +{ + HOST_WIDE_INT our_size; + + /* If this is not a static allocation, the only case we want to forbid + is an overflowing size. That will be converted into a raise a + Storage_Error. */ + if (!static_p) + return !(TREE_CODE (gnu_size) == INTEGER_CST + && TREE_OVERFLOW (gnu_size)); + + /* Otherwise, we need to deal with both variable sizes and constant + sizes that won't fit in a host int. We use int instead of HOST_WIDE_INT + since assemblers may not like very large sizes. */ + if (!host_integerp (gnu_size, 1)) + return false; + + our_size = tree_low_cst (gnu_size, 1); + return (int) our_size == our_size; +} + +/* Prepend to ATTR_LIST an entry for an attribute with provided TYPE, + NAME, ARGS and ERROR_POINT. */ + +static void +prepend_one_attribute_to (struct attrib ** attr_list, + enum attr_type attr_type, + tree attr_name, + tree attr_args, + Node_Id attr_error_point) +{ + struct attrib * attr = (struct attrib *) xmalloc (sizeof (struct attrib)); + + attr->type = attr_type; + attr->name = attr_name; + attr->args = attr_args; + attr->error_point = attr_error_point; + + attr->next = *attr_list; + *attr_list = attr; +} + +/* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */ + +static void +prepend_attributes (Entity_Id gnat_entity, struct attrib ** attr_list) +{ + Node_Id gnat_temp; + + /* Attributes are stored as Representation Item pragmas. */ + + for (gnat_temp = First_Rep_Item (gnat_entity); Present (gnat_temp); + gnat_temp = Next_Rep_Item (gnat_temp)) + if (Nkind (gnat_temp) == N_Pragma) + { + tree gnu_arg0 = NULL_TREE, gnu_arg1 = NULL_TREE; + Node_Id gnat_assoc = Pragma_Argument_Associations (gnat_temp); + enum attr_type etype; + + /* Map the kind of pragma at hand. Skip if this is not one + we know how to handle. */ + + switch (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_temp)))) + { + case Pragma_Machine_Attribute: + etype = ATTR_MACHINE_ATTRIBUTE; + break; + + case Pragma_Linker_Alias: + etype = ATTR_LINK_ALIAS; + break; + + case Pragma_Linker_Section: + etype = ATTR_LINK_SECTION; + break; + + case Pragma_Linker_Constructor: + etype = ATTR_LINK_CONSTRUCTOR; + break; + + case Pragma_Linker_Destructor: + etype = ATTR_LINK_DESTRUCTOR; + break; + + case Pragma_Weak_External: + etype = ATTR_WEAK_EXTERNAL; + break; + + case Pragma_Thread_Local_Storage: + etype = ATTR_THREAD_LOCAL_STORAGE; + break; + + default: + continue; + } + + /* See what arguments we have and turn them into GCC trees for + attribute handlers. These expect identifier for strings. We + handle at most two arguments, static expressions only. */ + + if (Present (gnat_assoc) && Present (First (gnat_assoc))) + { + Node_Id gnat_arg0 = Next (First (gnat_assoc)); + Node_Id gnat_arg1 = Empty; + + if (Present (gnat_arg0) + && Is_Static_Expression (Expression (gnat_arg0))) + { + gnu_arg0 = gnat_to_gnu (Expression (gnat_arg0)); + + if (TREE_CODE (gnu_arg0) == STRING_CST) + gnu_arg0 = get_identifier (TREE_STRING_POINTER (gnu_arg0)); + + gnat_arg1 = Next (gnat_arg0); + } + + if (Present (gnat_arg1) + && Is_Static_Expression (Expression (gnat_arg1))) + { + gnu_arg1 = gnat_to_gnu (Expression (gnat_arg1)); + + if (TREE_CODE (gnu_arg1) == STRING_CST) + gnu_arg1 = get_identifier (TREE_STRING_POINTER (gnu_arg1)); + } + } + + /* Prepend to the list now. Make a list of the argument we might + have, as GCC expects it. */ + prepend_one_attribute_to + (attr_list, + etype, gnu_arg0, + (gnu_arg1 != NULL_TREE) + ? build_tree_list (NULL_TREE, gnu_arg1) : NULL_TREE, + Present (Next (First (gnat_assoc))) + ? Expression (Next (First (gnat_assoc))) : gnat_temp); + } +} + +/* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a + type definition (either a bound or a discriminant value) for GNAT_ENTITY, + return the GCC tree to use for that expression. GNU_NAME is the suffix + to use if a variable needs to be created and DEFINITION is true if this + is a definition of GNAT_ENTITY. If NEED_VALUE is true, we need a result; + otherwise, we are just elaborating the expression for side-effects. If + NEED_DEBUG is true, we need a variable for debugging purposes even if it + isn't needed for code generation. */ + +static tree +elaborate_expression (Node_Id gnat_expr, Entity_Id gnat_entity, tree gnu_name, + bool definition, bool need_value, bool need_debug) +{ + tree gnu_expr; + + /* If we already elaborated this expression (e.g. it was involved + in the definition of a private type), use the old value. */ + if (present_gnu_tree (gnat_expr)) + return get_gnu_tree (gnat_expr); + + /* If we don't need a value and this is static or a discriminant, + we don't need to do anything. */ + if (!need_value + && (Is_OK_Static_Expression (gnat_expr) + || (Nkind (gnat_expr) == N_Identifier + && Ekind (Entity (gnat_expr)) == E_Discriminant))) + return NULL_TREE; + + /* If it's a static expression, we don't need a variable for debugging. */ + if (need_debug && Is_OK_Static_Expression (gnat_expr)) + need_debug = false; + + /* Otherwise, convert this tree to its GCC equivalent and elaborate it. */ + gnu_expr = elaborate_expression_1 (gnat_to_gnu (gnat_expr), gnat_entity, + gnu_name, definition, need_debug); + + /* Save the expression in case we try to elaborate this entity again. Since + it's not a DECL, don't check it. Don't save if it's a discriminant. */ + if (!CONTAINS_PLACEHOLDER_P (gnu_expr)) + save_gnu_tree (gnat_expr, gnu_expr, true); + + return need_value ? gnu_expr : error_mark_node; +} + +/* Similar, but take a GNU expression and always return a result. */ + +static tree +elaborate_expression_1 (tree gnu_expr, Entity_Id gnat_entity, tree gnu_name, + bool definition, bool need_debug) +{ + /* Skip any conversions and simple arithmetics to see if the expression + is a read-only variable. + ??? This really should remain read-only, but we have to think about + the typing of the tree here. */ + tree gnu_inner_expr + = skip_simple_arithmetic (remove_conversions (gnu_expr, true)); + tree gnu_decl = NULL_TREE; + bool expr_global = Is_Public (gnat_entity) || global_bindings_p (); + bool expr_variable; + + /* In most cases, we won't see a naked FIELD_DECL because a discriminant + reference will have been replaced with a COMPONENT_REF when the type + is being elaborated. However, there are some cases involving child + types where we will. So convert it to a COMPONENT_REF. We hope it + will be at the highest level of the expression in these cases. */ + if (TREE_CODE (gnu_expr) == FIELD_DECL) + gnu_expr = build3 (COMPONENT_REF, TREE_TYPE (gnu_expr), + build0 (PLACEHOLDER_EXPR, DECL_CONTEXT (gnu_expr)), + gnu_expr, NULL_TREE); + + /* If GNU_EXPR is neither a placeholder nor a constant, nor a variable + that is read-only, make a variable that is initialized to contain the + bound when the package containing the definition is elaborated. If + this entity is defined at top level and a bound or discriminant value + isn't a constant or a reference to a discriminant, replace the bound + by the variable; otherwise use a SAVE_EXPR if needed. Note that we + rely here on the fact that an expression cannot contain both the + discriminant and some other variable. */ + expr_variable = (!CONSTANT_CLASS_P (gnu_expr) + && !(TREE_CODE (gnu_inner_expr) == VAR_DECL + && (TREE_READONLY (gnu_inner_expr) + || DECL_READONLY_ONCE_ELAB (gnu_inner_expr))) + && !CONTAINS_PLACEHOLDER_P (gnu_expr)); + + /* If GNU_EXPR contains a discriminant, we can't elaborate a variable. */ + if (need_debug && CONTAINS_PLACEHOLDER_P (gnu_expr)) + need_debug = false; + + /* Now create the variable if we need it. */ + if (need_debug || (expr_variable && expr_global)) + gnu_decl + = create_var_decl (create_concat_name (gnat_entity, + IDENTIFIER_POINTER (gnu_name)), + NULL_TREE, TREE_TYPE (gnu_expr), gnu_expr, + !need_debug, Is_Public (gnat_entity), + !definition, expr_global, NULL, gnat_entity); + + /* We only need to use this variable if we are in global context since GCC + can do the right thing in the local case. */ + if (expr_global && expr_variable) + return gnu_decl; + + return expr_variable ? gnat_save_expr (gnu_expr) : gnu_expr; +} + +/* Similar, but take an alignment factor and make it explicit in the tree. */ + +static tree +elaborate_expression_2 (tree gnu_expr, Entity_Id gnat_entity, tree gnu_name, + bool definition, bool need_debug, unsigned int align) +{ + tree unit_align = size_int (align / BITS_PER_UNIT); + return + size_binop (MULT_EXPR, + elaborate_expression_1 (size_binop (EXACT_DIV_EXPR, + gnu_expr, + unit_align), + gnat_entity, gnu_name, definition, + need_debug), + unit_align); +} + +/* Create a record type that contains a SIZE bytes long field of TYPE with a + starting bit position so that it is aligned to ALIGN bits, and leaving at + least ROOM bytes free before the field. BASE_ALIGN is the alignment the + record is guaranteed to get. */ + +tree +make_aligning_type (tree type, unsigned int align, tree size, + unsigned int base_align, int room) +{ + /* We will be crafting a record type with one field at a position set to be + the next multiple of ALIGN past record'address + room bytes. We use a + record placeholder to express record'address. */ + tree record_type = make_node (RECORD_TYPE); + tree record = build0 (PLACEHOLDER_EXPR, record_type); + + tree record_addr_st + = convert (sizetype, build_unary_op (ADDR_EXPR, NULL_TREE, record)); + + /* The diagram below summarizes the shape of what we manipulate: + + <--------- pos ----------> + { +------------+-------------+-----------------+ + record =>{ |############| ... | field (type) | + { +------------+-------------+-----------------+ + |<-- room -->|<- voffset ->|<---- size ----->| + o o + | | + record_addr vblock_addr + + Every length is in sizetype bytes there, except "pos" which has to be + set as a bit position in the GCC tree for the record. */ + tree room_st = size_int (room); + tree vblock_addr_st = size_binop (PLUS_EXPR, record_addr_st, room_st); + tree voffset_st, pos, field; + + tree name = TYPE_NAME (type); + + if (TREE_CODE (name) == TYPE_DECL) + name = DECL_NAME (name); + name = concat_name (name, "ALIGN"); + TYPE_NAME (record_type) = name; + + /* Compute VOFFSET and then POS. The next byte position multiple of some + alignment after some address is obtained by "and"ing the alignment minus + 1 with the two's complement of the address. */ + voffset_st = size_binop (BIT_AND_EXPR, + fold_build1 (NEGATE_EXPR, sizetype, vblock_addr_st), + size_int ((align / BITS_PER_UNIT) - 1)); + + /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */ + pos = size_binop (MULT_EXPR, + convert (bitsizetype, + size_binop (PLUS_EXPR, room_st, voffset_st)), + bitsize_unit_node); + + /* Craft the GCC record representation. We exceptionally do everything + manually here because 1) our generic circuitry is not quite ready to + handle the complex position/size expressions we are setting up, 2) we + have a strong simplifying factor at hand: we know the maximum possible + value of voffset, and 3) we have to set/reset at least the sizes in + accordance with this maximum value anyway, as we need them to convey + what should be "alloc"ated for this type. + + Use -1 as the 'addressable' indication for the field to prevent the + creation of a bitfield. We don't need one, it would have damaging + consequences on the alignment computation, and create_field_decl would + make one without this special argument, for instance because of the + complex position expression. */ + field = create_field_decl (get_identifier ("F"), type, record_type, size, + pos, 1, -1); + TYPE_FIELDS (record_type) = field; + + TYPE_ALIGN (record_type) = base_align; + TYPE_USER_ALIGN (record_type) = 1; + + TYPE_SIZE (record_type) + = size_binop (PLUS_EXPR, + size_binop (MULT_EXPR, convert (bitsizetype, size), + bitsize_unit_node), + bitsize_int (align + room * BITS_PER_UNIT)); + TYPE_SIZE_UNIT (record_type) + = size_binop (PLUS_EXPR, size, + size_int (room + align / BITS_PER_UNIT)); + + SET_TYPE_MODE (record_type, BLKmode); + relate_alias_sets (record_type, type, ALIAS_SET_COPY); + + /* Declare it now since it will never be declared otherwise. This is + necessary to ensure that its subtrees are properly marked. */ + create_type_decl (name, record_type, NULL, true, false, Empty); + + return record_type; +} + +/* Return the result of rounding T up to ALIGN. */ + +static inline unsigned HOST_WIDE_INT +round_up_to_align (unsigned HOST_WIDE_INT t, unsigned int align) +{ + t += align - 1; + t /= align; + t *= align; + return t; +} + +/* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used + as the field type of a packed record if IN_RECORD is true, or as the + component type of a packed array if IN_RECORD is false. See if we can + rewrite it either as a type that has a non-BLKmode, which we can pack + tighter in the packed record case, or as a smaller type. If so, return + the new type. If not, return the original type. */ + +static tree +make_packable_type (tree type, bool in_record) +{ + unsigned HOST_WIDE_INT size = tree_low_cst (TYPE_SIZE (type), 1); + unsigned HOST_WIDE_INT new_size; + tree new_type, old_field, field_list = NULL_TREE; + + /* No point in doing anything if the size is zero. */ + if (size == 0) + return type; + + new_type = make_node (TREE_CODE (type)); + + /* Copy the name and flags from the old type to that of the new. + Note that we rely on the pointer equality created here for + TYPE_NAME to look through conversions in various places. */ + TYPE_NAME (new_type) = TYPE_NAME (type); + TYPE_JUSTIFIED_MODULAR_P (new_type) = TYPE_JUSTIFIED_MODULAR_P (type); + TYPE_CONTAINS_TEMPLATE_P (new_type) = TYPE_CONTAINS_TEMPLATE_P (type); + if (TREE_CODE (type) == RECORD_TYPE) + TYPE_PADDING_P (new_type) = TYPE_PADDING_P (type); + + /* If we are in a record and have a small size, set the alignment to + try for an integral mode. Otherwise set it to try for a smaller + type with BLKmode. */ + if (in_record && size <= MAX_FIXED_MODE_SIZE) + { + TYPE_ALIGN (new_type) = ceil_alignment (size); + new_size = round_up_to_align (size, TYPE_ALIGN (new_type)); + } + else + { + unsigned HOST_WIDE_INT align; + + /* Do not try to shrink the size if the RM size is not constant. */ + if (TYPE_CONTAINS_TEMPLATE_P (type) + || !host_integerp (TYPE_ADA_SIZE (type), 1)) + return type; + + /* Round the RM size up to a unit boundary to get the minimal size + for a BLKmode record. Give up if it's already the size. */ + new_size = TREE_INT_CST_LOW (TYPE_ADA_SIZE (type)); + new_size = round_up_to_align (new_size, BITS_PER_UNIT); + if (new_size == size) + return type; + + align = new_size & -new_size; + TYPE_ALIGN (new_type) = MIN (TYPE_ALIGN (type), align); + } + + TYPE_USER_ALIGN (new_type) = 1; + + /* Now copy the fields, keeping the position and size as we don't want + to change the layout by propagating the packedness downwards. */ + for (old_field = TYPE_FIELDS (type); old_field; + old_field = DECL_CHAIN (old_field)) + { + tree new_field_type = TREE_TYPE (old_field); + tree new_field, new_size; + + if ((TREE_CODE (new_field_type) == RECORD_TYPE + || TREE_CODE (new_field_type) == UNION_TYPE + || TREE_CODE (new_field_type) == QUAL_UNION_TYPE) + && !TYPE_FAT_POINTER_P (new_field_type) + && host_integerp (TYPE_SIZE (new_field_type), 1)) + new_field_type = make_packable_type (new_field_type, true); + + /* However, for the last field in a not already packed record type + that is of an aggregate type, we need to use the RM size in the + packable version of the record type, see finish_record_type. */ + if (!DECL_CHAIN (old_field) + && !TYPE_PACKED (type) + && (TREE_CODE (new_field_type) == RECORD_TYPE + || TREE_CODE (new_field_type) == UNION_TYPE + || TREE_CODE (new_field_type) == QUAL_UNION_TYPE) + && !TYPE_FAT_POINTER_P (new_field_type) + && !TYPE_CONTAINS_TEMPLATE_P (new_field_type) + && TYPE_ADA_SIZE (new_field_type)) + new_size = TYPE_ADA_SIZE (new_field_type); + else + new_size = DECL_SIZE (old_field); + + new_field + = create_field_decl (DECL_NAME (old_field), new_field_type, new_type, + new_size, bit_position (old_field), + TYPE_PACKED (type), + !DECL_NONADDRESSABLE_P (old_field)); + + DECL_INTERNAL_P (new_field) = DECL_INTERNAL_P (old_field); + SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, old_field); + if (TREE_CODE (new_type) == QUAL_UNION_TYPE) + DECL_QUALIFIER (new_field) = DECL_QUALIFIER (old_field); + + DECL_CHAIN (new_field) = field_list; + field_list = new_field; + } + + finish_record_type (new_type, nreverse (field_list), 2, false); + relate_alias_sets (new_type, type, ALIAS_SET_COPY); + + /* If this is a padding record, we never want to make the size smaller + than what was specified. For QUAL_UNION_TYPE, also copy the size. */ + if (TYPE_IS_PADDING_P (type) || TREE_CODE (type) == QUAL_UNION_TYPE) + { + TYPE_SIZE (new_type) = TYPE_SIZE (type); + TYPE_SIZE_UNIT (new_type) = TYPE_SIZE_UNIT (type); + new_size = size; + } + else + { + TYPE_SIZE (new_type) = bitsize_int (new_size); + TYPE_SIZE_UNIT (new_type) + = size_int ((new_size + BITS_PER_UNIT - 1) / BITS_PER_UNIT); + } + + if (!TYPE_CONTAINS_TEMPLATE_P (type)) + SET_TYPE_ADA_SIZE (new_type, TYPE_ADA_SIZE (type)); + + compute_record_mode (new_type); + + /* Try harder to get a packable type if necessary, for example + in case the record itself contains a BLKmode field. */ + if (in_record && TYPE_MODE (new_type) == BLKmode) + SET_TYPE_MODE (new_type, + mode_for_size_tree (TYPE_SIZE (new_type), MODE_INT, 1)); + + /* If neither the mode nor the size has shrunk, return the old type. */ + if (TYPE_MODE (new_type) == BLKmode && new_size >= size) + return type; + + return new_type; +} + +/* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type + if needed. We have already verified that SIZE and TYPE are large enough. + GNAT_ENTITY is used to name the resulting record and to issue a warning. + IS_COMPONENT_TYPE is true if this is being done for the component type + of an array. IS_USER_TYPE is true if we must complete the original type. + DEFINITION is true if this type is being defined. SAME_RM_SIZE is true + if the RM size of the resulting type is to be set to SIZE too; otherwise, + it's set to the RM size of the original type. */ + +tree +maybe_pad_type (tree type, tree size, unsigned int align, + Entity_Id gnat_entity, bool is_component_type, + bool is_user_type, bool definition, bool same_rm_size) +{ + tree orig_rm_size = same_rm_size ? NULL_TREE : rm_size (type); + tree orig_size = TYPE_SIZE (type); + tree record, field; + + /* If TYPE is a padded type, see if it agrees with any size and alignment + we were given. If so, return the original type. Otherwise, strip + off the padding, since we will either be returning the inner type + or repadding it. If no size or alignment is specified, use that of + the original padded type. */ + if (TYPE_IS_PADDING_P (type)) + { + if ((!size + || operand_equal_p (round_up (size, + MAX (align, TYPE_ALIGN (type))), + round_up (TYPE_SIZE (type), + MAX (align, TYPE_ALIGN (type))), + 0)) + && (align == 0 || align == TYPE_ALIGN (type))) + return type; + + if (!size) + size = TYPE_SIZE (type); + if (align == 0) + align = TYPE_ALIGN (type); + + type = TREE_TYPE (TYPE_FIELDS (type)); + orig_size = TYPE_SIZE (type); + } + + /* If the size is either not being changed or is being made smaller (which + is not done here and is only valid for bitfields anyway), show the size + isn't changing. Likewise, clear the alignment if it isn't being + changed. Then return if we aren't doing anything. */ + if (size + && (operand_equal_p (size, orig_size, 0) + || (TREE_CODE (orig_size) == INTEGER_CST + && tree_int_cst_lt (size, orig_size)))) + size = NULL_TREE; + + if (align == TYPE_ALIGN (type)) + align = 0; + + if (align == 0 && !size) + return type; + + /* If requested, complete the original type and give it a name. */ + if (is_user_type) + create_type_decl (get_entity_name (gnat_entity), type, + NULL, !Comes_From_Source (gnat_entity), + !(TYPE_NAME (type) + && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL + && DECL_IGNORED_P (TYPE_NAME (type))), + gnat_entity); + + /* We used to modify the record in place in some cases, but that could + generate incorrect debugging information. So make a new record + type and name. */ + record = make_node (RECORD_TYPE); + TYPE_PADDING_P (record) = 1; + + if (Present (gnat_entity)) + TYPE_NAME (record) = create_concat_name (gnat_entity, "PAD"); + + TYPE_VOLATILE (record) + = Present (gnat_entity) && Treat_As_Volatile (gnat_entity); + + TYPE_ALIGN (record) = align; + TYPE_SIZE (record) = size ? size : orig_size; + TYPE_SIZE_UNIT (record) + = convert (sizetype, + size_binop (CEIL_DIV_EXPR, TYPE_SIZE (record), + bitsize_unit_node)); + + /* If we are changing the alignment and the input type is a record with + BLKmode and a small constant size, try to make a form that has an + integral mode. This might allow the padding record to also have an + integral mode, which will be much more efficient. There is no point + in doing so if a size is specified unless it is also a small constant + size and it is incorrect to do so if we cannot guarantee that the mode + will be naturally aligned since the field must always be addressable. + + ??? This might not always be a win when done for a stand-alone object: + since the nominal and the effective type of the object will now have + different modes, a VIEW_CONVERT_EXPR will be required for converting + between them and it might be hard to overcome afterwards, including + at the RTL level when the stand-alone object is accessed as a whole. */ + if (align != 0 + && TREE_CODE (type) == RECORD_TYPE + && TYPE_MODE (type) == BLKmode + && !TREE_ADDRESSABLE (type) + && TREE_CODE (orig_size) == INTEGER_CST + && !TREE_OVERFLOW (orig_size) + && compare_tree_int (orig_size, MAX_FIXED_MODE_SIZE) <= 0 + && (!size + || (TREE_CODE (size) == INTEGER_CST + && compare_tree_int (size, MAX_FIXED_MODE_SIZE) <= 0))) + { + tree packable_type = make_packable_type (type, true); + if (TYPE_MODE (packable_type) != BLKmode + && align >= TYPE_ALIGN (packable_type)) + type = packable_type; + } + + /* Now create the field with the original size. */ + field = create_field_decl (get_identifier ("F"), type, record, orig_size, + bitsize_zero_node, 0, 1); + DECL_INTERNAL_P (field) = 1; + + /* Do not emit debug info until after the auxiliary record is built. */ + finish_record_type (record, field, 1, false); + + /* Set the same size for its RM size if requested; otherwise reuse + the RM size of the original type. */ + SET_TYPE_ADA_SIZE (record, same_rm_size ? size : orig_rm_size); + + /* Unless debugging information isn't being written for the input type, + write a record that shows what we are a subtype of and also make a + variable that indicates our size, if still variable. */ + if (TREE_CODE (orig_size) != INTEGER_CST + && TYPE_NAME (record) + && TYPE_NAME (type) + && !(TREE_CODE (TYPE_NAME (type)) == TYPE_DECL + && DECL_IGNORED_P (TYPE_NAME (type)))) + { + tree marker = make_node (RECORD_TYPE); + tree name = TYPE_NAME (record); + tree orig_name = TYPE_NAME (type); + + if (TREE_CODE (name) == TYPE_DECL) + name = DECL_NAME (name); + + if (TREE_CODE (orig_name) == TYPE_DECL) + orig_name = DECL_NAME (orig_name); + + TYPE_NAME (marker) = concat_name (name, "XVS"); + finish_record_type (marker, + create_field_decl (orig_name, + build_reference_type (type), + marker, NULL_TREE, NULL_TREE, + 0, 0), + 0, true); + + add_parallel_type (TYPE_STUB_DECL (record), marker); + + if (definition && size && TREE_CODE (size) != INTEGER_CST) + TYPE_SIZE_UNIT (marker) + = create_var_decl (concat_name (name, "XVZ"), NULL_TREE, sizetype, + TYPE_SIZE_UNIT (record), false, false, false, + false, NULL, gnat_entity); + } + + rest_of_record_type_compilation (record); + + /* If the size was widened explicitly, maybe give a warning. Take the + original size as the maximum size of the input if there was an + unconstrained record involved and round it up to the specified alignment, + if one was specified. */ + if (CONTAINS_PLACEHOLDER_P (orig_size)) + orig_size = max_size (orig_size, true); + + if (align) + orig_size = round_up (orig_size, align); + + if (Present (gnat_entity) + && size + && TREE_CODE (size) != MAX_EXPR + && TREE_CODE (size) != COND_EXPR + && !operand_equal_p (size, orig_size, 0) + && !(TREE_CODE (size) == INTEGER_CST + && TREE_CODE (orig_size) == INTEGER_CST + && (TREE_OVERFLOW (size) + || TREE_OVERFLOW (orig_size) + || tree_int_cst_lt (size, orig_size)))) + { + Node_Id gnat_error_node = Empty; + + if (Is_Packed_Array_Type (gnat_entity)) + gnat_entity = Original_Array_Type (gnat_entity); + + if ((Ekind (gnat_entity) == E_Component + || Ekind (gnat_entity) == E_Discriminant) + && Present (Component_Clause (gnat_entity))) + gnat_error_node = Last_Bit (Component_Clause (gnat_entity)); + else if (Present (Size_Clause (gnat_entity))) + gnat_error_node = Expression (Size_Clause (gnat_entity)); + + /* Generate message only for entities that come from source, since + if we have an entity created by expansion, the message will be + generated for some other corresponding source entity. */ + if (Comes_From_Source (gnat_entity)) + { + if (Present (gnat_error_node)) + post_error_ne_tree ("{^ }bits of & unused?", + gnat_error_node, gnat_entity, + size_diffop (size, orig_size)); + else if (is_component_type) + post_error_ne_tree ("component of& padded{ by ^ bits}?", + gnat_entity, gnat_entity, + size_diffop (size, orig_size)); + } + } + + return record; +} + +/* Given a GNU tree and a GNAT list of choices, generate an expression to test + the value passed against the list of choices. */ + +tree +choices_to_gnu (tree operand, Node_Id choices) +{ + Node_Id choice; + Node_Id gnat_temp; + tree result = integer_zero_node; + tree this_test, low = 0, high = 0, single = 0; + + for (choice = First (choices); Present (choice); choice = Next (choice)) + { + switch (Nkind (choice)) + { + case N_Range: + low = gnat_to_gnu (Low_Bound (choice)); + high = gnat_to_gnu (High_Bound (choice)); + + this_test + = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node, + build_binary_op (GE_EXPR, boolean_type_node, + operand, low), + build_binary_op (LE_EXPR, boolean_type_node, + operand, high)); + + break; + + case N_Subtype_Indication: + gnat_temp = Range_Expression (Constraint (choice)); + low = gnat_to_gnu (Low_Bound (gnat_temp)); + high = gnat_to_gnu (High_Bound (gnat_temp)); + + this_test + = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node, + build_binary_op (GE_EXPR, boolean_type_node, + operand, low), + build_binary_op (LE_EXPR, boolean_type_node, + operand, high)); + break; + + case N_Identifier: + case N_Expanded_Name: + /* This represents either a subtype range, an enumeration + literal, or a constant Ekind says which. If an enumeration + literal or constant, fall through to the next case. */ + if (Ekind (Entity (choice)) != E_Enumeration_Literal + && Ekind (Entity (choice)) != E_Constant) + { + tree type = gnat_to_gnu_type (Entity (choice)); + + low = TYPE_MIN_VALUE (type); + high = TYPE_MAX_VALUE (type); + + this_test + = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node, + build_binary_op (GE_EXPR, boolean_type_node, + operand, low), + build_binary_op (LE_EXPR, boolean_type_node, + operand, high)); + break; + } + + /* ... fall through ... */ + + case N_Character_Literal: + case N_Integer_Literal: + single = gnat_to_gnu (choice); + this_test = build_binary_op (EQ_EXPR, boolean_type_node, operand, + single); + break; + + case N_Others_Choice: + this_test = integer_one_node; + break; + + default: + gcc_unreachable (); + } + + result = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, result, + this_test); + } + + return result; +} + +/* Adjust PACKED setting as passed to gnat_to_gnu_field for a field of + type FIELD_TYPE to be placed in RECORD_TYPE. Return the result. */ + +static int +adjust_packed (tree field_type, tree record_type, int packed) +{ + /* If the field contains an item of variable size, we cannot pack it + because we cannot create temporaries of non-fixed size in case + we need to take the address of the field. See addressable_p and + the notes on the addressability issues for further details. */ + if (is_variable_size (field_type)) + return 0; + + /* If the alignment of the record is specified and the field type + is over-aligned, request Storage_Unit alignment for the field. */ + if (packed == -2) + { + if (TYPE_ALIGN (field_type) > TYPE_ALIGN (record_type)) + return -1; + else + return 0; + } + + return packed; +} + +/* Return a GCC tree for a field corresponding to GNAT_FIELD to be + placed in GNU_RECORD_TYPE. + + PACKED is 1 if the enclosing record is packed, -1 if the enclosing + record has Component_Alignment of Storage_Unit, -2 if the enclosing + record has a specified alignment. + + DEFINITION is true if this field is for a record being defined. + + DEBUG_INFO_P is true if we need to write debug information for types + that we may create in the process. */ + +static tree +gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed, + bool definition, bool debug_info_p) +{ + tree gnu_field_id = get_entity_name (gnat_field); + tree gnu_field_type = gnat_to_gnu_type (Etype (gnat_field)); + tree gnu_field, gnu_size, gnu_pos; + bool needs_strict_alignment + = (Is_Aliased (gnat_field) || Strict_Alignment (Etype (gnat_field)) + || Treat_As_Volatile (gnat_field)); + + /* If this field requires strict alignment, we cannot pack it because + it would very likely be under-aligned in the record. */ + if (needs_strict_alignment) + packed = 0; + else + packed = adjust_packed (gnu_field_type, gnu_record_type, packed); + + /* If a size is specified, use it. Otherwise, if the record type is packed, + use the official RM size. See "Handling of Type'Size Values" in Einfo + for further details. */ + if (Known_Static_Esize (gnat_field)) + gnu_size = validate_size (Esize (gnat_field), gnu_field_type, + gnat_field, FIELD_DECL, false, true); + else if (packed == 1) + gnu_size = validate_size (RM_Size (Etype (gnat_field)), gnu_field_type, + gnat_field, FIELD_DECL, false, true); + else + gnu_size = NULL_TREE; + + /* If we have a specified size that is smaller than that of the field's type, + or a position is specified, and the field's type is a record that doesn't + require strict alignment, see if we can get either an integral mode form + of the type or a smaller form. If we can, show a size was specified for + the field if there wasn't one already, so we know to make this a bitfield + and avoid making things wider. + + Changing to an integral mode form is useful when the record is packed as + we can then place the field at a non-byte-aligned position and so achieve + tighter packing. This is in addition required if the field shares a byte + with another field and the front-end lets the back-end handle the access + to the field, because GCC cannot handle non-byte-aligned BLKmode fields. + + Changing to a smaller form is required if the specified size is smaller + than that of the field's type and the type contains sub-fields that are + padded, in order to avoid generating accesses to these sub-fields that + are wider than the field. + + We avoid the transformation if it is not required or potentially useful, + as it might entail an increase of the field's alignment and have ripple + effects on the outer record type. A typical case is a field known to be + byte-aligned and not to share a byte with another field. */ + if (!needs_strict_alignment + && TREE_CODE (gnu_field_type) == RECORD_TYPE + && !TYPE_FAT_POINTER_P (gnu_field_type) + && host_integerp (TYPE_SIZE (gnu_field_type), 1) + && (packed == 1 + || (gnu_size + && (tree_int_cst_lt (gnu_size, TYPE_SIZE (gnu_field_type)) + || (Present (Component_Clause (gnat_field)) + && !(UI_To_Int (Component_Bit_Offset (gnat_field)) + % BITS_PER_UNIT == 0 + && value_factor_p (gnu_size, BITS_PER_UNIT))))))) + { + tree gnu_packable_type = make_packable_type (gnu_field_type, true); + if (gnu_packable_type != gnu_field_type) + { + gnu_field_type = gnu_packable_type; + if (!gnu_size) + gnu_size = rm_size (gnu_field_type); + } + } + + /* If we are packing the record and the field is BLKmode, round the + size up to a byte boundary. */ + if (packed && TYPE_MODE (gnu_field_type) == BLKmode && gnu_size) + gnu_size = round_up (gnu_size, BITS_PER_UNIT); + + if (Present (Component_Clause (gnat_field))) + { + Entity_Id gnat_parent + = Parent_Subtype (Underlying_Type (Scope (gnat_field))); + + gnu_pos = UI_To_gnu (Component_Bit_Offset (gnat_field), bitsizetype); + gnu_size = validate_size (Esize (gnat_field), gnu_field_type, + gnat_field, FIELD_DECL, false, true); + + /* Ensure the position does not overlap with the parent subtype, if there + is one. This test is omitted if the parent of the tagged type has a + full rep clause since, in this case, component clauses are allowed to + overlay the space allocated for the parent type and the front-end has + checked that there are no overlapping components. */ + if (Present (gnat_parent) && !Is_Fully_Repped_Tagged_Type (gnat_parent)) + { + tree gnu_parent = gnat_to_gnu_type (gnat_parent); + + if (TREE_CODE (TYPE_SIZE (gnu_parent)) == INTEGER_CST + && tree_int_cst_lt (gnu_pos, TYPE_SIZE (gnu_parent))) + { + post_error_ne_tree + ("offset of& must be beyond parent{, minimum allowed is ^}", + First_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_SIZE_UNIT (gnu_parent)); + } + } + + /* If this field needs strict alignment, ensure the record is + sufficiently aligned and that that position and size are + consistent with the alignment. */ + if (needs_strict_alignment) + { + TYPE_ALIGN (gnu_record_type) + = MAX (TYPE_ALIGN (gnu_record_type), TYPE_ALIGN (gnu_field_type)); + + if (gnu_size + && !operand_equal_p (gnu_size, TYPE_SIZE (gnu_field_type), 0)) + { + if (Is_Atomic (gnat_field) || Is_Atomic (Etype (gnat_field))) + post_error_ne_tree + ("atomic field& must be natural size of type{ (^)}", + Last_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_SIZE (gnu_field_type)); + + else if (Is_Aliased (gnat_field)) + post_error_ne_tree + ("size of aliased field& must be ^ bits", + Last_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_SIZE (gnu_field_type)); + + else if (Strict_Alignment (Etype (gnat_field))) + post_error_ne_tree + ("size of & with aliased or tagged components not ^ bits", + Last_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_SIZE (gnu_field_type)); + + gnu_size = NULL_TREE; + } + + if (!integer_zerop (size_binop + (TRUNC_MOD_EXPR, gnu_pos, + bitsize_int (TYPE_ALIGN (gnu_field_type))))) + { + if (Is_Aliased (gnat_field)) + post_error_ne_num + ("position of aliased field& must be multiple of ^ bits", + First_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_ALIGN (gnu_field_type)); + + else if (Treat_As_Volatile (gnat_field)) + post_error_ne_num + ("position of volatile field& must be multiple of ^ bits", + First_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_ALIGN (gnu_field_type)); + + else if (Strict_Alignment (Etype (gnat_field))) + post_error_ne_num + ("position of & with aliased or tagged components not multiple of ^ bits", + First_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_ALIGN (gnu_field_type)); + + else + gcc_unreachable (); + + gnu_pos = NULL_TREE; + } + } + + if (Is_Atomic (gnat_field)) + check_ok_for_atomic (gnu_field_type, gnat_field, false); + } + + /* If the record has rep clauses and this is the tag field, make a rep + clause for it as well. */ + else if (Has_Specified_Layout (Scope (gnat_field)) + && Chars (gnat_field) == Name_uTag) + { + gnu_pos = bitsize_zero_node; + gnu_size = TYPE_SIZE (gnu_field_type); + } + + else + gnu_pos = NULL_TREE; + + /* We need to make the size the maximum for the type if it is + self-referential and an unconstrained type. In that case, we can't + pack the field since we can't make a copy to align it. */ + if (TREE_CODE (gnu_field_type) == RECORD_TYPE + && !gnu_size + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_field_type)) + && !Is_Constrained (Underlying_Type (Etype (gnat_field)))) + { + gnu_size = max_size (TYPE_SIZE (gnu_field_type), true); + packed = 0; + } + + /* If a size is specified, adjust the field's type to it. */ + if (gnu_size) + { + tree orig_field_type; + + /* If the field's type is justified modular, we would need to remove + the wrapper to (better) meet the layout requirements. However we + can do so only if the field is not aliased to preserve the unique + layout and if the prescribed size is not greater than that of the + packed array to preserve the justification. */ + if (!needs_strict_alignment + && TREE_CODE (gnu_field_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type) + && tree_int_cst_compare (gnu_size, TYPE_ADA_SIZE (gnu_field_type)) + <= 0) + gnu_field_type = TREE_TYPE (TYPE_FIELDS (gnu_field_type)); + + gnu_field_type + = make_type_from_size (gnu_field_type, gnu_size, + Has_Biased_Representation (gnat_field)); + + orig_field_type = gnu_field_type; + gnu_field_type = maybe_pad_type (gnu_field_type, gnu_size, 0, gnat_field, + false, false, definition, true); + + /* If a padding record was made, declare it now since it will never be + declared otherwise. This is necessary to ensure that its subtrees + are properly marked. */ + if (gnu_field_type != orig_field_type + && !DECL_P (TYPE_NAME (gnu_field_type))) + create_type_decl (TYPE_NAME (gnu_field_type), gnu_field_type, NULL, + true, debug_info_p, gnat_field); + } + + /* Otherwise (or if there was an error), don't specify a position. */ + else + gnu_pos = NULL_TREE; + + gcc_assert (TREE_CODE (gnu_field_type) != RECORD_TYPE + || !TYPE_CONTAINS_TEMPLATE_P (gnu_field_type)); + + /* Now create the decl for the field. */ + gnu_field + = create_field_decl (gnu_field_id, gnu_field_type, gnu_record_type, + gnu_size, gnu_pos, packed, Is_Aliased (gnat_field)); + Sloc_to_locus (Sloc (gnat_field), &DECL_SOURCE_LOCATION (gnu_field)); + TREE_THIS_VOLATILE (gnu_field) = Treat_As_Volatile (gnat_field); + + if (Ekind (gnat_field) == E_Discriminant) + DECL_DISCRIMINANT_NUMBER (gnu_field) + = UI_To_gnu (Discriminant_Number (gnat_field), sizetype); + + return gnu_field; +} + +/* Return true if TYPE is a type with variable size, a padding type with a + field of variable size or is a record that has a field such a field. */ + +static bool +is_variable_size (tree type) +{ + tree field; + + if (!TREE_CONSTANT (TYPE_SIZE (type))) + return true; + + if (TYPE_IS_PADDING_P (type) + && !TREE_CONSTANT (DECL_SIZE (TYPE_FIELDS (type)))) + return true; + + if (TREE_CODE (type) != RECORD_TYPE + && TREE_CODE (type) != UNION_TYPE + && TREE_CODE (type) != QUAL_UNION_TYPE) + return false; + + for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) + if (is_variable_size (TREE_TYPE (field))) + return true; + + return false; +} + +/* qsort comparer for the bit positions of two record components. */ + +static int +compare_field_bitpos (const PTR rt1, const PTR rt2) +{ + const_tree const field1 = * (const_tree const *) rt1; + const_tree const field2 = * (const_tree const *) rt2; + const int ret + = tree_int_cst_compare (bit_position (field1), bit_position (field2)); + + return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2)); +} + +/* Translate and chain the GNAT_COMPONENT_LIST to the GNU_FIELD_LIST, set + the result as the field list of GNU_RECORD_TYPE and finish it up. When + called from gnat_to_gnu_entity during the processing of a record type + definition, the GCC node for the parent, if any, will be the single field + of GNU_RECORD_TYPE and the GCC nodes for the discriminants will be on the + GNU_FIELD_LIST. The other calls to this function are recursive calls for + the component list of a variant and, in this case, GNU_FIELD_LIST is empty. + + PACKED is 1 if this is for a packed record, -1 if this is for a record + with Component_Alignment of Storage_Unit, -2 if this is for a record + with a specified alignment. + + DEFINITION is true if we are defining this record type. + + P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field + with a rep clause is to be added; in this case, that is all that should + be done with such fields. + + CANCEL_ALIGNMENT is true if the alignment should be zeroed before laying + out the record. This means the alignment only serves to force fields to + be bitfields, but not to require the record to be that aligned. This is + used for variants. + + ALL_REP is true if a rep clause is present for all the fields. + + UNCHECKED_UNION is true if we are building this type for a record with a + Pragma Unchecked_Union. + + DEBUG_INFO_P is true if we need to write debug information about the type. + + MAYBE_UNUSED is true if this type may be unused in the end; this doesn't + mean that its contents may be unused as well, but only the container. */ + + +static void +components_to_record (tree gnu_record_type, Node_Id gnat_component_list, + tree gnu_field_list, int packed, bool definition, + tree *p_gnu_rep_list, bool cancel_alignment, + bool all_rep, bool unchecked_union, bool debug_info_p, + bool maybe_unused) +{ + bool all_rep_and_size = all_rep && TYPE_SIZE (gnu_record_type); + bool layout_with_rep = false; + Node_Id component_decl, variant_part; + tree gnu_our_rep_list = NULL_TREE; + tree gnu_field, gnu_next, gnu_last = tree_last (gnu_field_list); + + /* For each component referenced in a component declaration create a GCC + field and add it to the list, skipping pragmas in the GNAT list. */ + if (Present (Component_Items (gnat_component_list))) + for (component_decl + = First_Non_Pragma (Component_Items (gnat_component_list)); + Present (component_decl); + component_decl = Next_Non_Pragma (component_decl)) + { + Entity_Id gnat_field = Defining_Entity (component_decl); + Name_Id gnat_name = Chars (gnat_field); + + /* If present, the _Parent field must have been created as the single + field of the record type. Put it before any other fields. */ + if (gnat_name == Name_uParent) + { + gnu_field = TYPE_FIELDS (gnu_record_type); + gnu_field_list = chainon (gnu_field_list, gnu_field); + } + else + { + gnu_field = gnat_to_gnu_field (gnat_field, gnu_record_type, packed, + definition, debug_info_p); + + /* If this is the _Tag field, put it before any other fields. */ + if (gnat_name == Name_uTag) + gnu_field_list = chainon (gnu_field_list, gnu_field); + + /* If this is the _Controller field, put it before the other + fields except for the _Tag or _Parent field. */ + else if (gnat_name == Name_uController && gnu_last) + { + DECL_CHAIN (gnu_field) = DECL_CHAIN (gnu_last); + DECL_CHAIN (gnu_last) = gnu_field; + } + + /* If this is a regular field, put it after the other fields. */ + else + { + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + if (!gnu_last) + gnu_last = gnu_field; + } + } + + save_gnu_tree (gnat_field, gnu_field, false); + } + + /* At the end of the component list there may be a variant part. */ + variant_part = Variant_Part (gnat_component_list); + + /* We create a QUAL_UNION_TYPE for the variant part since the variants are + mutually exclusive and should go in the same memory. To do this we need + to treat each variant as a record whose elements are created from the + component list for the variant. So here we create the records from the + lists for the variants and put them all into the QUAL_UNION_TYPE. + If this is an Unchecked_Union, we make a UNION_TYPE instead or + use GNU_RECORD_TYPE if there are no fields so far. */ + if (Present (variant_part)) + { + Node_Id gnat_discr = Name (variant_part), variant; + tree gnu_discr = gnat_to_gnu (gnat_discr); + tree gnu_name = TYPE_NAME (gnu_record_type); + tree gnu_var_name + = concat_name (get_identifier (Get_Name_String (Chars (gnat_discr))), + "XVN"); + tree gnu_union_type, gnu_union_name, gnu_union_field; + tree gnu_variant_list = NULL_TREE; + + if (TREE_CODE (gnu_name) == TYPE_DECL) + gnu_name = DECL_NAME (gnu_name); + + gnu_union_name + = concat_name (gnu_name, IDENTIFIER_POINTER (gnu_var_name)); + + /* Reuse an enclosing union if all fields are in the variant part + and there is no representation clause on the record, to match + the layout of C unions. There is an associated check below. */ + if (!gnu_field_list + && TREE_CODE (gnu_record_type) == UNION_TYPE + && !TYPE_PACKED (gnu_record_type)) + gnu_union_type = gnu_record_type; + else + { + gnu_union_type + = make_node (unchecked_union ? UNION_TYPE : QUAL_UNION_TYPE); + + TYPE_NAME (gnu_union_type) = gnu_union_name; + TYPE_ALIGN (gnu_union_type) = 0; + TYPE_PACKED (gnu_union_type) = TYPE_PACKED (gnu_record_type); + } + + for (variant = First_Non_Pragma (Variants (variant_part)); + Present (variant); + variant = Next_Non_Pragma (variant)) + { + tree gnu_variant_type = make_node (RECORD_TYPE); + tree gnu_inner_name; + tree gnu_qual; + + Get_Variant_Encoding (variant); + gnu_inner_name = get_identifier_with_length (Name_Buffer, Name_Len); + TYPE_NAME (gnu_variant_type) + = concat_name (gnu_union_name, + IDENTIFIER_POINTER (gnu_inner_name)); + + /* Set the alignment of the inner type in case we need to make + inner objects into bitfields, but then clear it out so the + record actually gets only the alignment required. */ + TYPE_ALIGN (gnu_variant_type) = TYPE_ALIGN (gnu_record_type); + TYPE_PACKED (gnu_variant_type) = TYPE_PACKED (gnu_record_type); + + /* Similarly, if the outer record has a size specified and all + fields have record rep clauses, we can propagate the size + into the variant part. */ + if (all_rep_and_size) + { + TYPE_SIZE (gnu_variant_type) = TYPE_SIZE (gnu_record_type); + TYPE_SIZE_UNIT (gnu_variant_type) + = TYPE_SIZE_UNIT (gnu_record_type); + } + + /* Add the fields into the record type for the variant. Note that + we aren't sure to really use it at this point, see below. */ + components_to_record (gnu_variant_type, Component_List (variant), + NULL_TREE, packed, definition, + &gnu_our_rep_list, !all_rep_and_size, all_rep, + unchecked_union, debug_info_p, true); + + gnu_qual = choices_to_gnu (gnu_discr, Discrete_Choices (variant)); + + Set_Present_Expr (variant, annotate_value (gnu_qual)); + + /* If this is an Unchecked_Union and we have exactly one field, + use this field directly to match the layout of C unions. */ + if (unchecked_union + && TYPE_FIELDS (gnu_variant_type) + && !DECL_CHAIN (TYPE_FIELDS (gnu_variant_type))) + gnu_field = TYPE_FIELDS (gnu_variant_type); + else + { + /* Deal with packedness like in gnat_to_gnu_field. */ + int field_packed + = adjust_packed (gnu_variant_type, gnu_record_type, packed); + + /* Finalize the record type now. We used to throw away + empty records but we no longer do that because we need + them to generate complete debug info for the variant; + otherwise, the union type definition will be lacking + the fields associated with these empty variants. */ + rest_of_record_type_compilation (gnu_variant_type); + create_type_decl (TYPE_NAME (gnu_variant_type), gnu_variant_type, + NULL, true, debug_info_p, gnat_component_list); + + gnu_field + = create_field_decl (gnu_inner_name, gnu_variant_type, + gnu_union_type, + all_rep_and_size + ? TYPE_SIZE (gnu_variant_type) : 0, + all_rep_and_size + ? bitsize_zero_node : 0, + field_packed, 0); + + DECL_INTERNAL_P (gnu_field) = 1; + + if (!unchecked_union) + DECL_QUALIFIER (gnu_field) = gnu_qual; + } + + DECL_CHAIN (gnu_field) = gnu_variant_list; + gnu_variant_list = gnu_field; + } + + /* Only make the QUAL_UNION_TYPE if there are non-empty variants. */ + if (gnu_variant_list) + { + int union_field_packed; + + if (all_rep_and_size) + { + TYPE_SIZE (gnu_union_type) = TYPE_SIZE (gnu_record_type); + TYPE_SIZE_UNIT (gnu_union_type) + = TYPE_SIZE_UNIT (gnu_record_type); + } + + finish_record_type (gnu_union_type, nreverse (gnu_variant_list), + all_rep_and_size ? 1 : 0, debug_info_p); + + /* If GNU_UNION_TYPE is our record type, it means we must have an + Unchecked_Union with no fields. Verify that and, if so, just + return. */ + if (gnu_union_type == gnu_record_type) + { + gcc_assert (unchecked_union + && !gnu_field_list + && !gnu_our_rep_list); + return; + } + + create_type_decl (TYPE_NAME (gnu_union_type), gnu_union_type, + NULL, true, debug_info_p, gnat_component_list); + + /* Deal with packedness like in gnat_to_gnu_field. */ + union_field_packed + = adjust_packed (gnu_union_type, gnu_record_type, packed); + + gnu_union_field + = create_field_decl (gnu_var_name, gnu_union_type, gnu_record_type, + all_rep ? TYPE_SIZE (gnu_union_type) : 0, + all_rep ? bitsize_zero_node : 0, + union_field_packed, 0); + + DECL_INTERNAL_P (gnu_union_field) = 1; + DECL_CHAIN (gnu_union_field) = gnu_field_list; + gnu_field_list = gnu_union_field; + } + } + + /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they + do, pull them out and put them into GNU_OUR_REP_LIST. We have to do + this in a separate pass since we want to handle the discriminants but + can't play with them until we've used them in debugging data above. + + ??? If we then reorder them, debugging information will be wrong but + there's nothing that can be done about this at the moment. */ + gnu_last = NULL_TREE; + for (gnu_field = gnu_field_list; gnu_field; gnu_field = gnu_next) + { + gnu_next = DECL_CHAIN (gnu_field); + + if (DECL_FIELD_OFFSET (gnu_field)) + { + if (!gnu_last) + gnu_field_list = gnu_next; + else + DECL_CHAIN (gnu_last) = gnu_next; + + DECL_CHAIN (gnu_field) = gnu_our_rep_list; + gnu_our_rep_list = gnu_field; + } + else + gnu_last = gnu_field; + } + + /* If we have any fields in our rep'ed field list and it is not the case that + all the fields in the record have rep clauses and P_REP_LIST is nonzero, + set it and ignore these fields. */ + if (gnu_our_rep_list && p_gnu_rep_list && !all_rep) + *p_gnu_rep_list = chainon (*p_gnu_rep_list, gnu_our_rep_list); + + /* Otherwise, sort the fields by bit position and put them into their own + record, before the others, if we also have fields without rep clauses. */ + else if (gnu_our_rep_list) + { + tree gnu_rep_type + = (gnu_field_list ? make_node (RECORD_TYPE) : gnu_record_type); + int i, len = list_length (gnu_our_rep_list); + tree *gnu_arr = XALLOCAVEC (tree, len); + + for (gnu_field = gnu_our_rep_list, i = 0; + gnu_field; + gnu_field = DECL_CHAIN (gnu_field), i++) + gnu_arr[i] = gnu_field; + + qsort (gnu_arr, len, sizeof (tree), compare_field_bitpos); + + /* Put the fields in the list in order of increasing position, which + means we start from the end. */ + gnu_our_rep_list = NULL_TREE; + for (i = len - 1; i >= 0; i--) + { + DECL_CHAIN (gnu_arr[i]) = gnu_our_rep_list; + gnu_our_rep_list = gnu_arr[i]; + DECL_CONTEXT (gnu_arr[i]) = gnu_rep_type; + } + + if (gnu_field_list) + { + finish_record_type (gnu_rep_type, gnu_our_rep_list, 1, debug_info_p); + gnu_field + = create_field_decl (get_identifier ("REP"), gnu_rep_type, + gnu_record_type, NULL_TREE, NULL_TREE, 0, 1); + DECL_INTERNAL_P (gnu_field) = 1; + gnu_field_list = chainon (gnu_field_list, gnu_field); + } + else + { + layout_with_rep = true; + gnu_field_list = nreverse (gnu_our_rep_list); + } + } + + if (cancel_alignment) + TYPE_ALIGN (gnu_record_type) = 0; + + finish_record_type (gnu_record_type, nreverse (gnu_field_list), + layout_with_rep ? 1 : 0, debug_info_p && !maybe_unused); +} + +/* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be + placed into an Esize, Component_Bit_Offset, or Component_Size value + in the GNAT tree. */ + +static Uint +annotate_value (tree gnu_size) +{ + TCode tcode; + Node_Ref_Or_Val ops[3], ret; + struct tree_int_map **h = NULL; + int i; + + /* See if we've already saved the value for this node. */ + if (EXPR_P (gnu_size)) + { + struct tree_int_map in; + if (!annotate_value_cache) + annotate_value_cache = htab_create_ggc (512, tree_int_map_hash, + tree_int_map_eq, 0); + in.base.from = gnu_size; + h = (struct tree_int_map **) + htab_find_slot (annotate_value_cache, &in, INSERT); + + if (*h) + return (Node_Ref_Or_Val) (*h)->to; + } + + /* If we do not return inside this switch, TCODE will be set to the + code to use for a Create_Node operand and LEN (set above) will be + the number of recursive calls for us to make. */ + + switch (TREE_CODE (gnu_size)) + { + case INTEGER_CST: + if (TREE_OVERFLOW (gnu_size)) + return No_Uint; + + /* This may come from a conversion from some smaller type, so ensure + this is in bitsizetype. */ + gnu_size = convert (bitsizetype, gnu_size); + + /* For a negative value, build NEGATE_EXPR of the opposite. Such values + appear in expressions containing aligning patterns. Note that, since + sizetype is sign-extended but nonetheless unsigned, we don't directly + use tree_int_cst_sgn. */ + if (TREE_INT_CST_HIGH (gnu_size) < 0) + { + tree op_size = fold_build1 (NEGATE_EXPR, bitsizetype, gnu_size); + return annotate_value (build1 (NEGATE_EXPR, bitsizetype, op_size)); + } + + return UI_From_gnu (gnu_size); + + case COMPONENT_REF: + /* The only case we handle here is a simple discriminant reference. */ + if (TREE_CODE (TREE_OPERAND (gnu_size, 0)) == PLACEHOLDER_EXPR + && TREE_CODE (TREE_OPERAND (gnu_size, 1)) == FIELD_DECL + && DECL_DISCRIMINANT_NUMBER (TREE_OPERAND (gnu_size, 1))) + return Create_Node (Discrim_Val, + annotate_value (DECL_DISCRIMINANT_NUMBER + (TREE_OPERAND (gnu_size, 1))), + No_Uint, No_Uint); + else + return No_Uint; + + CASE_CONVERT: case NON_LVALUE_EXPR: + return annotate_value (TREE_OPERAND (gnu_size, 0)); + + /* Now just list the operations we handle. */ + case COND_EXPR: tcode = Cond_Expr; break; + case PLUS_EXPR: tcode = Plus_Expr; break; + case MINUS_EXPR: tcode = Minus_Expr; break; + case MULT_EXPR: tcode = Mult_Expr; break; + case TRUNC_DIV_EXPR: tcode = Trunc_Div_Expr; break; + case CEIL_DIV_EXPR: tcode = Ceil_Div_Expr; break; + case FLOOR_DIV_EXPR: tcode = Floor_Div_Expr; break; + case TRUNC_MOD_EXPR: tcode = Trunc_Mod_Expr; break; + case CEIL_MOD_EXPR: tcode = Ceil_Mod_Expr; break; + case FLOOR_MOD_EXPR: tcode = Floor_Mod_Expr; break; + case EXACT_DIV_EXPR: tcode = Exact_Div_Expr; break; + case NEGATE_EXPR: tcode = Negate_Expr; break; + case MIN_EXPR: tcode = Min_Expr; break; + case MAX_EXPR: tcode = Max_Expr; break; + case ABS_EXPR: tcode = Abs_Expr; break; + case TRUTH_ANDIF_EXPR: tcode = Truth_Andif_Expr; break; + case TRUTH_ORIF_EXPR: tcode = Truth_Orif_Expr; break; + case TRUTH_AND_EXPR: tcode = Truth_And_Expr; break; + case TRUTH_OR_EXPR: tcode = Truth_Or_Expr; break; + case TRUTH_XOR_EXPR: tcode = Truth_Xor_Expr; break; + case TRUTH_NOT_EXPR: tcode = Truth_Not_Expr; break; + case BIT_AND_EXPR: tcode = Bit_And_Expr; break; + case LT_EXPR: tcode = Lt_Expr; break; + case LE_EXPR: tcode = Le_Expr; break; + case GT_EXPR: tcode = Gt_Expr; break; + case GE_EXPR: tcode = Ge_Expr; break; + case EQ_EXPR: tcode = Eq_Expr; break; + case NE_EXPR: tcode = Ne_Expr; break; + + case CALL_EXPR: + { + tree t = maybe_inline_call_in_expr (gnu_size); + if (t) + return annotate_value (t); + } + + /* Fall through... */ + + default: + return No_Uint; + } + + /* Now get each of the operands that's relevant for this code. If any + cannot be expressed as a repinfo node, say we can't. */ + for (i = 0; i < 3; i++) + ops[i] = No_Uint; + + for (i = 0; i < TREE_CODE_LENGTH (TREE_CODE (gnu_size)); i++) + { + ops[i] = annotate_value (TREE_OPERAND (gnu_size, i)); + if (ops[i] == No_Uint) + return No_Uint; + } + + ret = Create_Node (tcode, ops[0], ops[1], ops[2]); + + /* Save the result in the cache. */ + if (h) + { + *h = ggc_alloc_tree_int_map (); + (*h)->base.from = gnu_size; + (*h)->to = ret; + } + + return ret; +} + +/* Given GNAT_ENTITY, an object (constant, variable, parameter, exception) + and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the + size and alignment used by Gigi. Prefer SIZE over TYPE_SIZE if non-null. + BY_REF is true if the object is used by reference and BY_DOUBLE_REF is + true if the object is used by double reference. */ + +void +annotate_object (Entity_Id gnat_entity, tree gnu_type, tree size, bool by_ref, + bool by_double_ref) +{ + if (by_ref) + { + if (by_double_ref) + gnu_type = TREE_TYPE (gnu_type); + + if (TYPE_IS_FAT_POINTER_P (gnu_type)) + gnu_type = TYPE_UNCONSTRAINED_ARRAY (gnu_type); + else + gnu_type = TREE_TYPE (gnu_type); + } + + if (Unknown_Esize (gnat_entity)) + { + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type)) + size = TYPE_SIZE (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type)))); + else if (!size) + size = TYPE_SIZE (gnu_type); + + if (size) + Set_Esize (gnat_entity, annotate_value (size)); + } + + if (Unknown_Alignment (gnat_entity)) + Set_Alignment (gnat_entity, + UI_From_Int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT)); +} + +/* Return first element of field list whose TREE_PURPOSE is the same as ELEM. + Return NULL_TREE if there is no such element in the list. */ + +static tree +purpose_member_field (const_tree elem, tree list) +{ + while (list) + { + tree field = TREE_PURPOSE (list); + if (SAME_FIELD_P (field, elem)) + return list; + list = TREE_CHAIN (list); + } + return NULL_TREE; +} + +/* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding GCC type, + set Component_Bit_Offset and Esize of the components to the position and + size used by Gigi. */ + +static void +annotate_rep (Entity_Id gnat_entity, tree gnu_type) +{ + Entity_Id gnat_field; + tree gnu_list; + + /* We operate by first making a list of all fields and their position (we + can get the size easily) and then update all the sizes in the tree. */ + gnu_list + = build_position_list (gnu_type, false, size_zero_node, bitsize_zero_node, + BIGGEST_ALIGNMENT, NULL_TREE); + + for (gnat_field = First_Entity (gnat_entity); + Present (gnat_field); + gnat_field = Next_Entity (gnat_field)) + if (Ekind (gnat_field) == E_Component + || (Ekind (gnat_field) == E_Discriminant + && !Is_Unchecked_Union (Scope (gnat_field)))) + { + tree t = purpose_member_field (gnat_to_gnu_field_decl (gnat_field), + gnu_list); + if (t) + { + tree parent_offset; + + if (type_annotate_only && Is_Tagged_Type (gnat_entity)) + { + /* In this mode the tag and parent components are not + generated, so we add the appropriate offset to each + component. For a component appearing in the current + extension, the offset is the size of the parent. */ + if (Is_Derived_Type (gnat_entity) + && Original_Record_Component (gnat_field) == gnat_field) + parent_offset + = UI_To_gnu (Esize (Etype (Base_Type (gnat_entity))), + bitsizetype); + else + parent_offset = bitsize_int (POINTER_SIZE); + } + else + parent_offset = bitsize_zero_node; + + Set_Component_Bit_Offset + (gnat_field, + annotate_value + (size_binop (PLUS_EXPR, + bit_from_pos (TREE_VEC_ELT (TREE_VALUE (t), 0), + TREE_VEC_ELT (TREE_VALUE (t), 2)), + parent_offset))); + + Set_Esize (gnat_field, + annotate_value (DECL_SIZE (TREE_PURPOSE (t)))); + } + else if (Is_Tagged_Type (gnat_entity) && Is_Derived_Type (gnat_entity)) + { + /* If there is no entry, this is an inherited component whose + position is the same as in the parent type. */ + Set_Component_Bit_Offset + (gnat_field, + Component_Bit_Offset (Original_Record_Component (gnat_field))); + + Set_Esize (gnat_field, + Esize (Original_Record_Component (gnat_field))); + } + } +} + +/* Scan all fields in GNU_TYPE and return a TREE_LIST where TREE_PURPOSE is + the FIELD_DECL and TREE_VALUE a TREE_VEC containing the byte position, the + value to be placed into DECL_OFFSET_ALIGN and the bit position. The list + of fields is flattened, except for variant parts if DO_NOT_FLATTEN_VARIANT + is set to true. GNU_POS is to be added to the position, GNU_BITPOS to the + bit position, OFFSET_ALIGN is the present offset alignment. GNU_LIST is a + pre-existing list to be chained to the newly created entries. */ + +static tree +build_position_list (tree gnu_type, bool do_not_flatten_variant, tree gnu_pos, + tree gnu_bitpos, unsigned int offset_align, tree gnu_list) +{ + tree gnu_field; + + for (gnu_field = TYPE_FIELDS (gnu_type); + gnu_field; + gnu_field = DECL_CHAIN (gnu_field)) + { + tree gnu_our_bitpos = size_binop (PLUS_EXPR, gnu_bitpos, + DECL_FIELD_BIT_OFFSET (gnu_field)); + tree gnu_our_offset = size_binop (PLUS_EXPR, gnu_pos, + DECL_FIELD_OFFSET (gnu_field)); + unsigned int our_offset_align + = MIN (offset_align, DECL_OFFSET_ALIGN (gnu_field)); + tree v = make_tree_vec (3); + + TREE_VEC_ELT (v, 0) = gnu_our_offset; + TREE_VEC_ELT (v, 1) = size_int (our_offset_align); + TREE_VEC_ELT (v, 2) = gnu_our_bitpos; + gnu_list = tree_cons (gnu_field, v, gnu_list); + + /* Recurse on internal fields, flattening the nested fields except for + those in the variant part, if requested. */ + if (DECL_INTERNAL_P (gnu_field)) + { + tree gnu_field_type = TREE_TYPE (gnu_field); + if (do_not_flatten_variant + && TREE_CODE (gnu_field_type) == QUAL_UNION_TYPE) + gnu_list + = build_position_list (gnu_field_type, do_not_flatten_variant, + size_zero_node, bitsize_zero_node, + BIGGEST_ALIGNMENT, gnu_list); + else + gnu_list + = build_position_list (gnu_field_type, do_not_flatten_variant, + gnu_our_offset, gnu_our_bitpos, + our_offset_align, gnu_list); + } + } + + return gnu_list; +} + +/* Return a VEC describing the substitutions needed to reflect the + discriminant substitutions from GNAT_TYPE to GNAT_SUBTYPE. They can + be in any order. The values in an element of the VEC are in the form + of operands to SUBSTITUTE_IN_EXPR. DEFINITION is true if this is for + a definition of GNAT_SUBTYPE. */ + +static VEC(subst_pair,heap) * +build_subst_list (Entity_Id gnat_subtype, Entity_Id gnat_type, bool definition) +{ + VEC(subst_pair,heap) *gnu_vec = NULL; + Entity_Id gnat_discrim; + Node_Id gnat_value; + + for (gnat_discrim = First_Stored_Discriminant (gnat_type), + gnat_value = First_Elmt (Stored_Constraint (gnat_subtype)); + Present (gnat_discrim); + gnat_discrim = Next_Stored_Discriminant (gnat_discrim), + gnat_value = Next_Elmt (gnat_value)) + /* Ignore access discriminants. */ + if (!Is_Access_Type (Etype (Node (gnat_value)))) + { + tree gnu_field = gnat_to_gnu_field_decl (gnat_discrim); + tree replacement = convert (TREE_TYPE (gnu_field), + elaborate_expression + (Node (gnat_value), gnat_subtype, + get_entity_name (gnat_discrim), + definition, true, false)); + subst_pair *s = VEC_safe_push (subst_pair, heap, gnu_vec, NULL); + s->discriminant = gnu_field; + s->replacement = replacement; + } + + return gnu_vec; +} + +/* Scan all fields in QUAL_UNION_TYPE and return a VEC describing the + variants of QUAL_UNION_TYPE that are still relevant after applying + the substitutions described in SUBST_LIST. VARIANT_LIST is a + pre-existing VEC onto which newly created entries should be + pushed. */ + +static VEC(variant_desc,heap) * +build_variant_list (tree qual_union_type, VEC(subst_pair,heap) *subst_list, + VEC(variant_desc,heap) *variant_list) +{ + tree gnu_field; + + for (gnu_field = TYPE_FIELDS (qual_union_type); + gnu_field; + gnu_field = DECL_CHAIN (gnu_field)) + { + tree qual = DECL_QUALIFIER (gnu_field); + unsigned ix; + subst_pair *s; + + FOR_EACH_VEC_ELT_REVERSE (subst_pair, subst_list, ix, s) + qual = SUBSTITUTE_IN_EXPR (qual, s->discriminant, s->replacement); + + /* If the new qualifier is not unconditionally false, its variant may + still be accessed. */ + if (!integer_zerop (qual)) + { + variant_desc *v; + tree variant_type = TREE_TYPE (gnu_field), variant_subpart; + + v = VEC_safe_push (variant_desc, heap, variant_list, NULL); + v->type = variant_type; + v->field = gnu_field; + v->qual = qual; + v->new_type = NULL_TREE; + + /* Recurse on the variant subpart of the variant, if any. */ + variant_subpart = get_variant_part (variant_type); + if (variant_subpart) + variant_list = build_variant_list (TREE_TYPE (variant_subpart), + subst_list, variant_list); + + /* If the new qualifier is unconditionally true, the subsequent + variants cannot be accessed. */ + if (integer_onep (qual)) + break; + } + } + + return variant_list; +} + +/* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE + corresponding to GNAT_OBJECT. If size is valid, return a tree corresponding + to its value. Otherwise return 0. KIND is VAR_DECL is we are specifying + the size for an object, TYPE_DECL for the size of a type, and FIELD_DECL + for the size of a field. COMPONENT_P is true if we are being called + to process the Component_Size of GNAT_OBJECT. This is used for error + message handling and to indicate to use the object size of GNU_TYPE. + ZERO_OK is true if a size of zero is permitted; if ZERO_OK is false, + it means that a size of zero should be treated as an unspecified size. */ + +static tree +validate_size (Uint uint_size, tree gnu_type, Entity_Id gnat_object, + enum tree_code kind, bool component_p, bool zero_ok) +{ + Node_Id gnat_error_node; + tree type_size, size; + + /* Return 0 if no size was specified. */ + if (uint_size == No_Uint) + return NULL_TREE; + + /* Ignore a negative size since that corresponds to our back-annotation. */ + if (UI_Lt (uint_size, Uint_0)) + return NULL_TREE; + + /* Find the node to use for errors. */ + if ((Ekind (gnat_object) == E_Component + || Ekind (gnat_object) == E_Discriminant) + && Present (Component_Clause (gnat_object))) + gnat_error_node = Last_Bit (Component_Clause (gnat_object)); + else if (Present (Size_Clause (gnat_object))) + gnat_error_node = Expression (Size_Clause (gnat_object)); + else + gnat_error_node = gnat_object; + + /* Get the size as a tree. Issue an error if a size was specified but + cannot be represented in sizetype. */ + size = UI_To_gnu (uint_size, bitsizetype); + if (TREE_OVERFLOW (size)) + { + if (component_p) + post_error_ne ("component size of & is too large", gnat_error_node, + gnat_object); + else + post_error_ne ("size of & is too large", gnat_error_node, + gnat_object); + return NULL_TREE; + } + + /* Ignore a zero size if it is not permitted. */ + if (!zero_ok && integer_zerop (size)) + return NULL_TREE; + + /* The size of objects is always a multiple of a byte. */ + if (kind == VAR_DECL + && !integer_zerop (size_binop (TRUNC_MOD_EXPR, size, bitsize_unit_node))) + { + if (component_p) + post_error_ne ("component size for& is not a multiple of Storage_Unit", + gnat_error_node, gnat_object); + else + post_error_ne ("size for& is not a multiple of Storage_Unit", + gnat_error_node, gnat_object); + return NULL_TREE; + } + + /* If this is an integral type or a packed array type, the front-end has + verified the size, so we need not do it here (which would entail + checking against the bounds). However, if this is an aliased object, + it may not be smaller than the type of the object. */ + if ((INTEGRAL_TYPE_P (gnu_type) || TYPE_IS_PACKED_ARRAY_TYPE_P (gnu_type)) + && !(kind == VAR_DECL && Is_Aliased (gnat_object))) + return size; + + /* If the object is a record that contains a template, add the size of + the template to the specified size. */ + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type)) + size = size_binop (PLUS_EXPR, DECL_SIZE (TYPE_FIELDS (gnu_type)), size); + + if (kind == VAR_DECL + /* If a type needs strict alignment, a component of this type in + a packed record cannot be packed and thus uses the type size. */ + || (kind == TYPE_DECL && Strict_Alignment (gnat_object))) + type_size = TYPE_SIZE (gnu_type); + else + type_size = rm_size (gnu_type); + + /* Modify the size of the type to be that of the maximum size if it has a + discriminant. */ + if (type_size && CONTAINS_PLACEHOLDER_P (type_size)) + type_size = max_size (type_size, true); + + /* If this is an access type or a fat pointer, the minimum size is that given + by the smallest integral mode that's valid for pointers. */ + if (TREE_CODE (gnu_type) == POINTER_TYPE || TYPE_IS_FAT_POINTER_P (gnu_type)) + { + enum machine_mode p_mode = GET_CLASS_NARROWEST_MODE (MODE_INT); + while (!targetm.valid_pointer_mode (p_mode)) + p_mode = GET_MODE_WIDER_MODE (p_mode); + type_size = bitsize_int (GET_MODE_BITSIZE (p_mode)); + } + + /* If the size of the object is a constant, the new size must not be + smaller. */ + if (TREE_CODE (type_size) != INTEGER_CST + || TREE_OVERFLOW (type_size) + || tree_int_cst_lt (size, type_size)) + { + if (component_p) + post_error_ne_tree + ("component size for& too small{, minimum allowed is ^}", + gnat_error_node, gnat_object, type_size); + else + post_error_ne_tree + ("size for& too small{, minimum allowed is ^}", + gnat_error_node, gnat_object, type_size); + + size = NULL_TREE; + } + + return size; +} + +/* Similarly, but both validate and process a value of RM size. This + routine is only called for types. */ + +static void +set_rm_size (Uint uint_size, tree gnu_type, Entity_Id gnat_entity) +{ + Node_Id gnat_attr_node; + tree old_size, size; + + /* Do nothing if no size was specified. */ + if (uint_size == No_Uint) + return; + + /* Ignore a negative size since that corresponds to our back-annotation. */ + if (UI_Lt (uint_size, Uint_0)) + return; + + /* Only issue an error if a Value_Size clause was explicitly given. + Otherwise, we'd be duplicating an error on the Size clause. */ + gnat_attr_node + = Get_Attribute_Definition_Clause (gnat_entity, Attr_Value_Size); + + /* Get the size as a tree. Issue an error if a size was specified but + cannot be represented in sizetype. */ + size = UI_To_gnu (uint_size, bitsizetype); + if (TREE_OVERFLOW (size)) + { + if (Present (gnat_attr_node)) + post_error_ne ("Value_Size of & is too large", gnat_attr_node, + gnat_entity); + return; + } + + /* Ignore a zero size unless a Value_Size clause exists, or a size clause + exists, or this is an integer type, in which case the front-end will + have always set it. */ + if (No (gnat_attr_node) + && integer_zerop (size) + && !Has_Size_Clause (gnat_entity) + && !Is_Discrete_Or_Fixed_Point_Type (gnat_entity)) + return; + + old_size = rm_size (gnu_type); + + /* If the old size is self-referential, get the maximum size. */ + if (CONTAINS_PLACEHOLDER_P (old_size)) + old_size = max_size (old_size, true); + + /* If the size of the object is a constant, the new size must not be smaller + (the front-end has verified this for scalar and packed array types). */ + if (TREE_CODE (old_size) != INTEGER_CST + || TREE_OVERFLOW (old_size) + || (AGGREGATE_TYPE_P (gnu_type) + && !(TREE_CODE (gnu_type) == ARRAY_TYPE + && TYPE_PACKED_ARRAY_TYPE_P (gnu_type)) + && !(TYPE_IS_PADDING_P (gnu_type) + && TREE_CODE (TREE_TYPE (TYPE_FIELDS (gnu_type))) == ARRAY_TYPE + && TYPE_PACKED_ARRAY_TYPE_P + (TREE_TYPE (TYPE_FIELDS (gnu_type)))) + && tree_int_cst_lt (size, old_size))) + { + if (Present (gnat_attr_node)) + post_error_ne_tree + ("Value_Size for& too small{, minimum allowed is ^}", + gnat_attr_node, gnat_entity, old_size); + return; + } + + /* Otherwise, set the RM size proper for integral types... */ + if ((TREE_CODE (gnu_type) == INTEGER_TYPE + && Is_Discrete_Or_Fixed_Point_Type (gnat_entity)) + || (TREE_CODE (gnu_type) == ENUMERAL_TYPE + || TREE_CODE (gnu_type) == BOOLEAN_TYPE)) + SET_TYPE_RM_SIZE (gnu_type, size); + + /* ...or the Ada size for record and union types. */ + else if ((TREE_CODE (gnu_type) == RECORD_TYPE + || TREE_CODE (gnu_type) == UNION_TYPE + || TREE_CODE (gnu_type) == QUAL_UNION_TYPE) + && !TYPE_FAT_POINTER_P (gnu_type)) + SET_TYPE_ADA_SIZE (gnu_type, size); +} + +/* Given a type TYPE, return a new type whose size is appropriate for SIZE. + If TYPE is the best type, return it. Otherwise, make a new type. We + only support new integral and pointer types. FOR_BIASED is true if + we are making a biased type. */ + +static tree +make_type_from_size (tree type, tree size_tree, bool for_biased) +{ + unsigned HOST_WIDE_INT size; + bool biased_p; + tree new_type; + + /* If size indicates an error, just return TYPE to avoid propagating + the error. Likewise if it's too large to represent. */ + if (!size_tree || !host_integerp (size_tree, 1)) + return type; + + size = tree_low_cst (size_tree, 1); + + switch (TREE_CODE (type)) + { + case INTEGER_TYPE: + case ENUMERAL_TYPE: + case BOOLEAN_TYPE: + biased_p = (TREE_CODE (type) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (type)); + + /* Integer types with precision 0 are forbidden. */ + if (size == 0) + size = 1; + + /* Only do something if the type is not a packed array type and + doesn't already have the proper size. */ + if (TYPE_PACKED_ARRAY_TYPE_P (type) + || (TYPE_PRECISION (type) == size && biased_p == for_biased)) + break; + + biased_p |= for_biased; + if (size > LONG_LONG_TYPE_SIZE) + size = LONG_LONG_TYPE_SIZE; + + if (TYPE_UNSIGNED (type) || biased_p) + new_type = make_unsigned_type (size); + else + new_type = make_signed_type (size); + TREE_TYPE (new_type) = TREE_TYPE (type) ? TREE_TYPE (type) : type; + SET_TYPE_RM_MIN_VALUE (new_type, + convert (TREE_TYPE (new_type), + TYPE_MIN_VALUE (type))); + SET_TYPE_RM_MAX_VALUE (new_type, + convert (TREE_TYPE (new_type), + TYPE_MAX_VALUE (type))); + /* Copy the name to show that it's essentially the same type and + not a subrange type. */ + TYPE_NAME (new_type) = TYPE_NAME (type); + TYPE_BIASED_REPRESENTATION_P (new_type) = biased_p; + SET_TYPE_RM_SIZE (new_type, bitsize_int (size)); + return new_type; + + case RECORD_TYPE: + /* Do something if this is a fat pointer, in which case we + may need to return the thin pointer. */ + if (TYPE_FAT_POINTER_P (type) && size < POINTER_SIZE * 2) + { + enum machine_mode p_mode = mode_for_size (size, MODE_INT, 0); + if (!targetm.valid_pointer_mode (p_mode)) + p_mode = ptr_mode; + return + build_pointer_type_for_mode + (TYPE_OBJECT_RECORD_TYPE (TYPE_UNCONSTRAINED_ARRAY (type)), + p_mode, 0); + } + break; + + case POINTER_TYPE: + /* Only do something if this is a thin pointer, in which case we + may need to return the fat pointer. */ + if (TYPE_IS_THIN_POINTER_P (type) && size >= POINTER_SIZE * 2) + return + build_pointer_type (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))); + break; + + default: + break; + } + + return type; +} + +/* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY, + a type or object whose present alignment is ALIGN. If this alignment is + valid, return it. Otherwise, give an error and return ALIGN. */ + +static unsigned int +validate_alignment (Uint alignment, Entity_Id gnat_entity, unsigned int align) +{ + unsigned int max_allowed_alignment = get_target_maximum_allowed_alignment (); + unsigned int new_align; + Node_Id gnat_error_node; + + /* Don't worry about checking alignment if alignment was not specified + by the source program and we already posted an error for this entity. */ + if (Error_Posted (gnat_entity) && !Has_Alignment_Clause (gnat_entity)) + return align; + + /* Post the error on the alignment clause if any. Note, for the implicit + base type of an array type, the alignment clause is on the first + subtype. */ + if (Present (Alignment_Clause (gnat_entity))) + gnat_error_node = Expression (Alignment_Clause (gnat_entity)); + + else if (Is_Itype (gnat_entity) + && Is_Array_Type (gnat_entity) + && Etype (gnat_entity) == gnat_entity + && Present (Alignment_Clause (First_Subtype (gnat_entity)))) + gnat_error_node = + Expression (Alignment_Clause (First_Subtype (gnat_entity))); + + else + gnat_error_node = gnat_entity; + + /* Within GCC, an alignment is an integer, so we must make sure a value is + specified that fits in that range. Also, there is an upper bound to + alignments we can support/allow. */ + if (!UI_Is_In_Int_Range (alignment) + || ((new_align = UI_To_Int (alignment)) > max_allowed_alignment)) + post_error_ne_num ("largest supported alignment for& is ^", + gnat_error_node, gnat_entity, max_allowed_alignment); + else if (!(Present (Alignment_Clause (gnat_entity)) + && From_At_Mod (Alignment_Clause (gnat_entity))) + && new_align * BITS_PER_UNIT < align) + { + unsigned int double_align; + bool is_capped_double, align_clause; + + /* If the default alignment of "double" or larger scalar types is + specifically capped and the new alignment is above the cap, do + not post an error and change the alignment only if there is an + alignment clause; this makes it possible to have the associated + GCC type overaligned by default for performance reasons. */ + if ((double_align = double_float_alignment) > 0) + { + Entity_Id gnat_type + = Is_Type (gnat_entity) ? gnat_entity : Etype (gnat_entity); + is_capped_double + = is_double_float_or_array (gnat_type, &align_clause); + } + else if ((double_align = double_scalar_alignment) > 0) + { + Entity_Id gnat_type + = Is_Type (gnat_entity) ? gnat_entity : Etype (gnat_entity); + is_capped_double + = is_double_scalar_or_array (gnat_type, &align_clause); + } + else + is_capped_double = align_clause = false; + + if (is_capped_double && new_align >= double_align) + { + if (align_clause) + align = new_align * BITS_PER_UNIT; + } + else + { + if (is_capped_double) + align = double_align * BITS_PER_UNIT; + + post_error_ne_num ("alignment for& must be at least ^", + gnat_error_node, gnat_entity, + align / BITS_PER_UNIT); + } + } + else + { + new_align = (new_align > 0 ? new_align * BITS_PER_UNIT : 1); + if (new_align > align) + align = new_align; + } + + return align; +} + +/* Return the smallest alignment not less than SIZE. */ + +static unsigned int +ceil_alignment (unsigned HOST_WIDE_INT size) +{ + return (unsigned int) 1 << (floor_log2 (size - 1) + 1); +} + +/* Verify that OBJECT, a type or decl, is something we can implement + atomically. If not, give an error for GNAT_ENTITY. COMP_P is true + if we require atomic components. */ + +static void +check_ok_for_atomic (tree object, Entity_Id gnat_entity, bool comp_p) +{ + Node_Id gnat_error_point = gnat_entity; + Node_Id gnat_node; + enum machine_mode mode; + unsigned int align; + tree size; + + /* There are three case of what OBJECT can be. It can be a type, in which + case we take the size, alignment and mode from the type. It can be a + declaration that was indirect, in which case the relevant values are + that of the type being pointed to, or it can be a normal declaration, + in which case the values are of the decl. The code below assumes that + OBJECT is either a type or a decl. */ + if (TYPE_P (object)) + { + /* If this is an anonymous base type, nothing to check. Error will be + reported on the source type. */ + if (!Comes_From_Source (gnat_entity)) + return; + + mode = TYPE_MODE (object); + align = TYPE_ALIGN (object); + size = TYPE_SIZE (object); + } + else if (DECL_BY_REF_P (object)) + { + mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (object))); + align = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (object))); + size = TYPE_SIZE (TREE_TYPE (TREE_TYPE (object))); + } + else + { + mode = DECL_MODE (object); + align = DECL_ALIGN (object); + size = DECL_SIZE (object); + } + + /* Consider all floating-point types atomic and any types that that are + represented by integers no wider than a machine word. */ + if (GET_MODE_CLASS (mode) == MODE_FLOAT + || ((GET_MODE_CLASS (mode) == MODE_INT + || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT) + && GET_MODE_BITSIZE (mode) <= BITS_PER_WORD)) + return; + + /* For the moment, also allow anything that has an alignment equal + to its size and which is smaller than a word. */ + if (size && TREE_CODE (size) == INTEGER_CST + && compare_tree_int (size, align) == 0 + && align <= BITS_PER_WORD) + return; + + for (gnat_node = First_Rep_Item (gnat_entity); Present (gnat_node); + gnat_node = Next_Rep_Item (gnat_node)) + { + if (!comp_p && Nkind (gnat_node) == N_Pragma + && (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node))) + == Pragma_Atomic)) + gnat_error_point = First (Pragma_Argument_Associations (gnat_node)); + else if (comp_p && Nkind (gnat_node) == N_Pragma + && (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node))) + == Pragma_Atomic_Components)) + gnat_error_point = First (Pragma_Argument_Associations (gnat_node)); + } + + if (comp_p) + post_error_ne ("atomic access to component of & cannot be guaranteed", + gnat_error_point, gnat_entity); + else + post_error_ne ("atomic access to & cannot be guaranteed", + gnat_error_point, gnat_entity); +} + + +/* Helper for the intrin compatibility checks family. Evaluate whether + two types are definitely incompatible. */ + +static bool +intrin_types_incompatible_p (tree t1, tree t2) +{ + enum tree_code code; + + if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) + return false; + + if (TYPE_MODE (t1) != TYPE_MODE (t2)) + return true; + + if (TREE_CODE (t1) != TREE_CODE (t2)) + return true; + + code = TREE_CODE (t1); + + switch (code) + { + case INTEGER_TYPE: + case REAL_TYPE: + return TYPE_PRECISION (t1) != TYPE_PRECISION (t2); + + case POINTER_TYPE: + case REFERENCE_TYPE: + /* Assume designated types are ok. We'd need to account for char * and + void * variants to do better, which could rapidly get messy and isn't + clearly worth the effort. */ + return false; + + default: + break; + } + + return false; +} + +/* Helper for intrin_profiles_compatible_p, to perform compatibility checks + on the Ada/builtin argument lists for the INB binding. */ + +static bool +intrin_arglists_compatible_p (intrin_binding_t * inb) +{ + tree ada_args = TYPE_ARG_TYPES (inb->ada_fntype); + tree btin_args = TYPE_ARG_TYPES (inb->btin_fntype); + + /* Sequence position of the last argument we checked. */ + int argpos = 0; + + while (ada_args != 0 || btin_args != 0) + { + tree ada_type, btin_type; + + /* If one list is shorter than the other, they fail to match. */ + if (ada_args == 0 || btin_args == 0) + return false; + + ada_type = TREE_VALUE (ada_args); + btin_type = TREE_VALUE (btin_args); + + /* If we're done with the Ada args and not with the internal builtin + args, or the other way around, complain. */ + if (ada_type == void_type_node + && btin_type != void_type_node) + { + post_error ("?Ada arguments list too short!", inb->gnat_entity); + return false; + } + + if (btin_type == void_type_node + && ada_type != void_type_node) + { + post_error_ne_num ("?Ada arguments list too long ('> ^)!", + inb->gnat_entity, inb->gnat_entity, argpos); + return false; + } + + /* Otherwise, check that types match for the current argument. */ + argpos ++; + if (intrin_types_incompatible_p (ada_type, btin_type)) + { + post_error_ne_num ("?intrinsic binding type mismatch on argument ^!", + inb->gnat_entity, inb->gnat_entity, argpos); + return false; + } + + ada_args = TREE_CHAIN (ada_args); + btin_args = TREE_CHAIN (btin_args); + } + + return true; +} + +/* Helper for intrin_profiles_compatible_p, to perform compatibility checks + on the Ada/builtin return values for the INB binding. */ + +static bool +intrin_return_compatible_p (intrin_binding_t * inb) +{ + tree ada_return_type = TREE_TYPE (inb->ada_fntype); + tree btin_return_type = TREE_TYPE (inb->btin_fntype); + + /* Accept function imported as procedure, common and convenient. */ + if (VOID_TYPE_P (ada_return_type) + && !VOID_TYPE_P (btin_return_type)) + return true; + + /* Check return types compatibility otherwise. Note that this + handles void/void as well. */ + if (intrin_types_incompatible_p (btin_return_type, ada_return_type)) + { + post_error ("?intrinsic binding type mismatch on return value!", + inb->gnat_entity); + return false; + } + + return true; +} + +/* Check and return whether the Ada and gcc builtin profiles bound by INB are + compatible. Issue relevant warnings when they are not. + + This is intended as a light check to diagnose the most obvious cases, not + as a full fledged type compatibility predicate. It is the programmer's + responsibility to ensure correctness of the Ada declarations in Imports, + especially when binding straight to a compiler internal. */ + +static bool +intrin_profiles_compatible_p (intrin_binding_t * inb) +{ + /* Check compatibility on return values and argument lists, each responsible + for posting warnings as appropriate. Ensure use of the proper sloc for + this purpose. */ + + bool arglists_compatible_p, return_compatible_p; + location_t saved_location = input_location; + + Sloc_to_locus (Sloc (inb->gnat_entity), &input_location); + + return_compatible_p = intrin_return_compatible_p (inb); + arglists_compatible_p = intrin_arglists_compatible_p (inb); + + input_location = saved_location; + + return return_compatible_p && arglists_compatible_p; +} + +/* Return a FIELD_DECL node modeled on OLD_FIELD. FIELD_TYPE is its type + and RECORD_TYPE is the type of the parent. If SIZE is nonzero, it is the + specified size for this field. POS_LIST is a position list describing + the layout of OLD_FIELD and SUBST_LIST a substitution list to be applied + to this layout. */ + +static tree +create_field_decl_from (tree old_field, tree field_type, tree record_type, + tree size, tree pos_list, + VEC(subst_pair,heap) *subst_list) +{ + tree t = TREE_VALUE (purpose_member (old_field, pos_list)); + tree pos = TREE_VEC_ELT (t, 0), bitpos = TREE_VEC_ELT (t, 2); + unsigned int offset_align = tree_low_cst (TREE_VEC_ELT (t, 1), 1); + tree new_pos, new_field; + unsigned ix; + subst_pair *s; + + if (CONTAINS_PLACEHOLDER_P (pos)) + FOR_EACH_VEC_ELT_REVERSE (subst_pair, subst_list, ix, s) + pos = SUBSTITUTE_IN_EXPR (pos, s->discriminant, s->replacement); + + /* If the position is now a constant, we can set it as the position of the + field when we make it. Otherwise, we need to deal with it specially. */ + if (TREE_CONSTANT (pos)) + new_pos = bit_from_pos (pos, bitpos); + else + new_pos = NULL_TREE; + + new_field + = create_field_decl (DECL_NAME (old_field), field_type, record_type, + size, new_pos, DECL_PACKED (old_field), + !DECL_NONADDRESSABLE_P (old_field)); + + if (!new_pos) + { + normalize_offset (&pos, &bitpos, offset_align); + DECL_FIELD_OFFSET (new_field) = pos; + DECL_FIELD_BIT_OFFSET (new_field) = bitpos; + SET_DECL_OFFSET_ALIGN (new_field, offset_align); + DECL_SIZE (new_field) = size; + DECL_SIZE_UNIT (new_field) + = convert (sizetype, + size_binop (CEIL_DIV_EXPR, size, bitsize_unit_node)); + layout_decl (new_field, DECL_OFFSET_ALIGN (new_field)); + } + + DECL_INTERNAL_P (new_field) = DECL_INTERNAL_P (old_field); + SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, old_field); + DECL_DISCRIMINANT_NUMBER (new_field) = DECL_DISCRIMINANT_NUMBER (old_field); + TREE_THIS_VOLATILE (new_field) = TREE_THIS_VOLATILE (old_field); + + return new_field; +} + +/* Return the REP part of RECORD_TYPE, if any. Otherwise return NULL. */ + +static tree +get_rep_part (tree record_type) +{ + tree field = TYPE_FIELDS (record_type); + + /* The REP part is the first field, internal, another record, and its name + doesn't start with an underscore (i.e. is not generated by the FE). */ + if (DECL_INTERNAL_P (field) + && TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE + && IDENTIFIER_POINTER (DECL_NAME (field)) [0] != '_') + return field; + + return NULL_TREE; +} + +/* Return the variant part of RECORD_TYPE, if any. Otherwise return NULL. */ + +tree +get_variant_part (tree record_type) +{ + tree field; + + /* The variant part is the only internal field that is a qualified union. */ + for (field = TYPE_FIELDS (record_type); field; field = DECL_CHAIN (field)) + if (DECL_INTERNAL_P (field) + && TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE) + return field; + + return NULL_TREE; +} + +/* Return a new variant part modeled on OLD_VARIANT_PART. VARIANT_LIST is + the list of variants to be used and RECORD_TYPE is the type of the parent. + POS_LIST is a position list describing the layout of fields present in + OLD_VARIANT_PART and SUBST_LIST a substitution list to be applied to this + layout. */ + +static tree +create_variant_part_from (tree old_variant_part, + VEC(variant_desc,heap) *variant_list, + tree record_type, tree pos_list, + VEC(subst_pair,heap) *subst_list) +{ + tree offset = DECL_FIELD_OFFSET (old_variant_part); + tree old_union_type = TREE_TYPE (old_variant_part); + tree new_union_type, new_variant_part; + tree union_field_list = NULL_TREE; + variant_desc *v; + unsigned ix; + + /* First create the type of the variant part from that of the old one. */ + new_union_type = make_node (QUAL_UNION_TYPE); + TYPE_NAME (new_union_type) + = concat_name (TYPE_NAME (record_type), + IDENTIFIER_POINTER (DECL_NAME (old_variant_part))); + + /* If the position of the variant part is constant, subtract it from the + size of the type of the parent to get the new size. This manual CSE + reduces the code size when not optimizing. */ + if (TREE_CODE (offset) == INTEGER_CST) + { + tree bitpos = DECL_FIELD_BIT_OFFSET (old_variant_part); + tree first_bit = bit_from_pos (offset, bitpos); + TYPE_SIZE (new_union_type) + = size_binop (MINUS_EXPR, TYPE_SIZE (record_type), first_bit); + TYPE_SIZE_UNIT (new_union_type) + = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (record_type), + byte_from_pos (offset, bitpos)); + SET_TYPE_ADA_SIZE (new_union_type, + size_binop (MINUS_EXPR, TYPE_ADA_SIZE (record_type), + first_bit)); + TYPE_ALIGN (new_union_type) = TYPE_ALIGN (old_union_type); + relate_alias_sets (new_union_type, old_union_type, ALIAS_SET_COPY); + } + else + copy_and_substitute_in_size (new_union_type, old_union_type, subst_list); + + /* Now finish up the new variants and populate the union type. */ + FOR_EACH_VEC_ELT_REVERSE (variant_desc, variant_list, ix, v) + { + tree old_field = v->field, new_field; + tree old_variant, old_variant_subpart, new_variant, field_list; + + /* Skip variants that don't belong to this nesting level. */ + if (DECL_CONTEXT (old_field) != old_union_type) + continue; + + /* Retrieve the list of fields already added to the new variant. */ + new_variant = v->new_type; + field_list = TYPE_FIELDS (new_variant); + + /* If the old variant had a variant subpart, we need to create a new + variant subpart and add it to the field list. */ + old_variant = v->type; + old_variant_subpart = get_variant_part (old_variant); + if (old_variant_subpart) + { + tree new_variant_subpart + = create_variant_part_from (old_variant_subpart, variant_list, + new_variant, pos_list, subst_list); + DECL_CHAIN (new_variant_subpart) = field_list; + field_list = new_variant_subpart; + } + + /* Finish up the new variant and create the field. No need for debug + info thanks to the XVS type. */ + finish_record_type (new_variant, nreverse (field_list), 2, false); + compute_record_mode (new_variant); + create_type_decl (TYPE_NAME (new_variant), new_variant, NULL, + true, false, Empty); + + new_field + = create_field_decl_from (old_field, new_variant, new_union_type, + TYPE_SIZE (new_variant), + pos_list, subst_list); + DECL_QUALIFIER (new_field) = v->qual; + DECL_INTERNAL_P (new_field) = 1; + DECL_CHAIN (new_field) = union_field_list; + union_field_list = new_field; + } + + /* Finish up the union type and create the variant part. No need for debug + info thanks to the XVS type. */ + finish_record_type (new_union_type, union_field_list, 2, false); + compute_record_mode (new_union_type); + create_type_decl (TYPE_NAME (new_union_type), new_union_type, NULL, + true, false, Empty); + + new_variant_part + = create_field_decl_from (old_variant_part, new_union_type, record_type, + TYPE_SIZE (new_union_type), + pos_list, subst_list); + DECL_INTERNAL_P (new_variant_part) = 1; + + /* With multiple discriminants it is possible for an inner variant to be + statically selected while outer ones are not; in this case, the list + of fields of the inner variant is not flattened and we end up with a + qualified union with a single member. Drop the useless container. */ + if (!DECL_CHAIN (union_field_list)) + { + DECL_CONTEXT (union_field_list) = record_type; + DECL_FIELD_OFFSET (union_field_list) + = DECL_FIELD_OFFSET (new_variant_part); + DECL_FIELD_BIT_OFFSET (union_field_list) + = DECL_FIELD_BIT_OFFSET (new_variant_part); + SET_DECL_OFFSET_ALIGN (union_field_list, + DECL_OFFSET_ALIGN (new_variant_part)); + new_variant_part = union_field_list; + } + + return new_variant_part; +} + +/* Copy the size (and alignment and alias set) from OLD_TYPE to NEW_TYPE, + which are both RECORD_TYPE, after applying the substitutions described + in SUBST_LIST. */ + +static void +copy_and_substitute_in_size (tree new_type, tree old_type, + VEC(subst_pair,heap) *subst_list) +{ + unsigned ix; + subst_pair *s; + + TYPE_SIZE (new_type) = TYPE_SIZE (old_type); + TYPE_SIZE_UNIT (new_type) = TYPE_SIZE_UNIT (old_type); + SET_TYPE_ADA_SIZE (new_type, TYPE_ADA_SIZE (old_type)); + TYPE_ALIGN (new_type) = TYPE_ALIGN (old_type); + relate_alias_sets (new_type, old_type, ALIAS_SET_COPY); + + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (new_type))) + FOR_EACH_VEC_ELT_REVERSE (subst_pair, subst_list, ix, s) + TYPE_SIZE (new_type) + = SUBSTITUTE_IN_EXPR (TYPE_SIZE (new_type), + s->discriminant, s->replacement); + + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (new_type))) + FOR_EACH_VEC_ELT_REVERSE (subst_pair, subst_list, ix, s) + TYPE_SIZE_UNIT (new_type) + = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (new_type), + s->discriminant, s->replacement); + + if (CONTAINS_PLACEHOLDER_P (TYPE_ADA_SIZE (new_type))) + FOR_EACH_VEC_ELT_REVERSE (subst_pair, subst_list, ix, s) + SET_TYPE_ADA_SIZE + (new_type, SUBSTITUTE_IN_EXPR (TYPE_ADA_SIZE (new_type), + s->discriminant, s->replacement)); + + /* Finalize the size. */ + TYPE_SIZE (new_type) = variable_size (TYPE_SIZE (new_type)); + TYPE_SIZE_UNIT (new_type) = variable_size (TYPE_SIZE_UNIT (new_type)); +} + +/* Given a type T, a FIELD_DECL F, and a replacement value R, return a + type with all size expressions that contain F in a PLACEHOLDER_EXPR + updated by replacing F with R. + + The function doesn't update the layout of the type, i.e. it assumes + that the substitution is purely formal. That's why the replacement + value R must itself contain a PLACEHOLDER_EXPR. */ + +tree +substitute_in_type (tree t, tree f, tree r) +{ + tree nt; + + gcc_assert (CONTAINS_PLACEHOLDER_P (r)); + + switch (TREE_CODE (t)) + { + case INTEGER_TYPE: + case ENUMERAL_TYPE: + case BOOLEAN_TYPE: + case REAL_TYPE: + + /* First the domain types of arrays. */ + if (CONTAINS_PLACEHOLDER_P (TYPE_GCC_MIN_VALUE (t)) + || CONTAINS_PLACEHOLDER_P (TYPE_GCC_MAX_VALUE (t))) + { + tree low = SUBSTITUTE_IN_EXPR (TYPE_GCC_MIN_VALUE (t), f, r); + tree high = SUBSTITUTE_IN_EXPR (TYPE_GCC_MAX_VALUE (t), f, r); + + if (low == TYPE_GCC_MIN_VALUE (t) && high == TYPE_GCC_MAX_VALUE (t)) + return t; + + nt = copy_type (t); + TYPE_GCC_MIN_VALUE (nt) = low; + TYPE_GCC_MAX_VALUE (nt) = high; + + if (TREE_CODE (t) == INTEGER_TYPE && TYPE_INDEX_TYPE (t)) + SET_TYPE_INDEX_TYPE + (nt, substitute_in_type (TYPE_INDEX_TYPE (t), f, r)); + + return nt; + } + + /* Then the subtypes. */ + if (CONTAINS_PLACEHOLDER_P (TYPE_RM_MIN_VALUE (t)) + || CONTAINS_PLACEHOLDER_P (TYPE_RM_MAX_VALUE (t))) + { + tree low = SUBSTITUTE_IN_EXPR (TYPE_RM_MIN_VALUE (t), f, r); + tree high = SUBSTITUTE_IN_EXPR (TYPE_RM_MAX_VALUE (t), f, r); + + if (low == TYPE_RM_MIN_VALUE (t) && high == TYPE_RM_MAX_VALUE (t)) + return t; + + nt = copy_type (t); + SET_TYPE_RM_MIN_VALUE (nt, low); + SET_TYPE_RM_MAX_VALUE (nt, high); + + return nt; + } + + return t; + + case COMPLEX_TYPE: + nt = substitute_in_type (TREE_TYPE (t), f, r); + if (nt == TREE_TYPE (t)) + return t; + + return build_complex_type (nt); + + case FUNCTION_TYPE: + /* These should never show up here. */ + gcc_unreachable (); + + case ARRAY_TYPE: + { + tree component = substitute_in_type (TREE_TYPE (t), f, r); + tree domain = substitute_in_type (TYPE_DOMAIN (t), f, r); + + if (component == TREE_TYPE (t) && domain == TYPE_DOMAIN (t)) + return t; + + nt = build_nonshared_array_type (component, domain); + TYPE_ALIGN (nt) = TYPE_ALIGN (t); + TYPE_USER_ALIGN (nt) = TYPE_USER_ALIGN (t); + SET_TYPE_MODE (nt, TYPE_MODE (t)); + TYPE_SIZE (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE (t), f, r); + TYPE_SIZE_UNIT (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (t), f, r); + TYPE_NONALIASED_COMPONENT (nt) = TYPE_NONALIASED_COMPONENT (t); + TYPE_MULTI_ARRAY_P (nt) = TYPE_MULTI_ARRAY_P (t); + TYPE_CONVENTION_FORTRAN_P (nt) = TYPE_CONVENTION_FORTRAN_P (t); + return nt; + } + + case RECORD_TYPE: + case UNION_TYPE: + case QUAL_UNION_TYPE: + { + bool changed_field = false; + tree field; + + /* Start out with no fields, make new fields, and chain them + in. If we haven't actually changed the type of any field, + discard everything we've done and return the old type. */ + nt = copy_type (t); + TYPE_FIELDS (nt) = NULL_TREE; + + for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) + { + tree new_field = copy_node (field), new_n; + + new_n = substitute_in_type (TREE_TYPE (field), f, r); + if (new_n != TREE_TYPE (field)) + { + TREE_TYPE (new_field) = new_n; + changed_field = true; + } + + new_n = SUBSTITUTE_IN_EXPR (DECL_FIELD_OFFSET (field), f, r); + if (new_n != DECL_FIELD_OFFSET (field)) + { + DECL_FIELD_OFFSET (new_field) = new_n; + changed_field = true; + } + + /* Do the substitution inside the qualifier, if any. */ + if (TREE_CODE (t) == QUAL_UNION_TYPE) + { + new_n = SUBSTITUTE_IN_EXPR (DECL_QUALIFIER (field), f, r); + if (new_n != DECL_QUALIFIER (field)) + { + DECL_QUALIFIER (new_field) = new_n; + changed_field = true; + } + } + + DECL_CONTEXT (new_field) = nt; + SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, field); + + DECL_CHAIN (new_field) = TYPE_FIELDS (nt); + TYPE_FIELDS (nt) = new_field; + } + + if (!changed_field) + return t; + + TYPE_FIELDS (nt) = nreverse (TYPE_FIELDS (nt)); + TYPE_SIZE (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE (t), f, r); + TYPE_SIZE_UNIT (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (t), f, r); + SET_TYPE_ADA_SIZE (nt, SUBSTITUTE_IN_EXPR (TYPE_ADA_SIZE (t), f, r)); + return nt; + } + + default: + return t; + } +} + +/* Return the RM size of GNU_TYPE. This is the actual number of bits + needed to represent the object. */ + +tree +rm_size (tree gnu_type) +{ + /* For integral types, we store the RM size explicitly. */ + if (INTEGRAL_TYPE_P (gnu_type) && TYPE_RM_SIZE (gnu_type)) + return TYPE_RM_SIZE (gnu_type); + + /* Return the RM size of the actual data plus the size of the template. */ + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type)) + return + size_binop (PLUS_EXPR, + rm_size (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type)))), + DECL_SIZE (TYPE_FIELDS (gnu_type))); + + /* For record types, we store the size explicitly. */ + if ((TREE_CODE (gnu_type) == RECORD_TYPE + || TREE_CODE (gnu_type) == UNION_TYPE + || TREE_CODE (gnu_type) == QUAL_UNION_TYPE) + && !TYPE_FAT_POINTER_P (gnu_type) + && TYPE_ADA_SIZE (gnu_type)) + return TYPE_ADA_SIZE (gnu_type); + + /* For other types, this is just the size. */ + return TYPE_SIZE (gnu_type); +} + +/* Return the name to be used for GNAT_ENTITY. If a type, create a + fully-qualified name, possibly with type information encoding. + Otherwise, return the name. */ + +tree +get_entity_name (Entity_Id gnat_entity) +{ + Get_Encoded_Name (gnat_entity); + return get_identifier_with_length (Name_Buffer, Name_Len); +} + +/* Return an identifier representing the external name to be used for + GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___" + and the specified suffix. */ + +tree +create_concat_name (Entity_Id gnat_entity, const char *suffix) +{ + Entity_Kind kind = Ekind (gnat_entity); + + if (suffix) + { + String_Template temp = {1, strlen (suffix)}; + Fat_Pointer fp = {suffix, &temp}; + Get_External_Name_With_Suffix (gnat_entity, fp); + } + else + Get_External_Name (gnat_entity, 0); + + /* A variable using the Stdcall convention lives in a DLL. We adjust + its name to use the jump table, the _imp__NAME contains the address + for the NAME variable. */ + if ((kind == E_Variable || kind == E_Constant) + && Has_Stdcall_Convention (gnat_entity)) + { + const int len = 6 + Name_Len; + char *new_name = (char *) alloca (len + 1); + strcpy (new_name, "_imp__"); + strcat (new_name, Name_Buffer); + return get_identifier_with_length (new_name, len); + } + + return get_identifier_with_length (Name_Buffer, Name_Len); +} + +/* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a + string, return a new IDENTIFIER_NODE that is the concatenation of + the name followed by "___" and the specified suffix. */ + +tree +concat_name (tree gnu_name, const char *suffix) +{ + const int len = IDENTIFIER_LENGTH (gnu_name) + 3 + strlen (suffix); + char *new_name = (char *) alloca (len + 1); + strcpy (new_name, IDENTIFIER_POINTER (gnu_name)); + strcat (new_name, "___"); + strcat (new_name, suffix); + return get_identifier_with_length (new_name, len); +} + +#include "gt-ada-decl.h" -- cgit v1.2.3