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authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/ada/sem_ch13.adb
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+------------------------------------------------------------------------------
+-- --
+-- GNAT COMPILER COMPONENTS --
+-- --
+-- S E M _ C H 1 3 --
+-- --
+-- B o d y --
+-- --
+-- Copyright (C) 1992-2010, 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 distributed with GNAT; see file COPYING3. If not, go to --
+-- http://www.gnu.org/licenses for a complete copy of the license. --
+-- --
+-- GNAT was originally developed by the GNAT team at New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc. --
+-- --
+------------------------------------------------------------------------------
+
+with Aspects; use Aspects;
+with Atree; use Atree;
+with Checks; use Checks;
+with Einfo; use Einfo;
+with Elists; use Elists;
+with Errout; use Errout;
+with Exp_Disp; use Exp_Disp;
+with Exp_Tss; use Exp_Tss;
+with Exp_Util; use Exp_Util;
+with Lib; use Lib;
+with Lib.Xref; use Lib.Xref;
+with Namet; use Namet;
+with Nlists; use Nlists;
+with Nmake; use Nmake;
+with Opt; use Opt;
+with Restrict; use Restrict;
+with Rident; use Rident;
+with Rtsfind; use Rtsfind;
+with Sem; use Sem;
+with Sem_Aux; use Sem_Aux;
+with Sem_Ch3; use Sem_Ch3;
+with Sem_Ch6; use Sem_Ch6;
+with Sem_Ch8; use Sem_Ch8;
+with Sem_Eval; use Sem_Eval;
+with Sem_Res; use Sem_Res;
+with Sem_Type; use Sem_Type;
+with Sem_Util; use Sem_Util;
+with Sem_Warn; use Sem_Warn;
+with Sinput; use Sinput;
+with Snames; use Snames;
+with Stand; use Stand;
+with Sinfo; use Sinfo;
+with Stringt; use Stringt;
+with Targparm; use Targparm;
+with Ttypes; use Ttypes;
+with Tbuild; use Tbuild;
+with Urealp; use Urealp;
+
+with GNAT.Heap_Sort_G;
+
+package body Sem_Ch13 is
+
+ SSU : constant Pos := System_Storage_Unit;
+ -- Convenient short hand for commonly used constant
+
+ -----------------------
+ -- Local Subprograms --
+ -----------------------
+
+ procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
+ -- This routine is called after setting the Esize of type entity Typ.
+ -- The purpose is to deal with the situation where an alignment has been
+ -- inherited from a derived type that is no longer appropriate for the
+ -- new Esize value. In this case, we reset the Alignment to unknown.
+
+ procedure Build_Predicate_Function (Typ : Entity_Id; N : Node_Id);
+ -- If Typ has predicates (indicated by Has_Predicates being set for Typ,
+ -- then either there are pragma Invariant entries on the rep chain for the
+ -- type (note that Predicate aspects are converted to pragma Predicate), or
+ -- there are inherited aspects from a parent type, or ancestor subtypes.
+ -- This procedure builds the spec and body for the Predicate function that
+ -- tests these predicates. N is the freeze node for the type. The spec of
+ -- the function is inserted before the freeze node, and the body of the
+ -- function is inserted after the freeze node.
+
+ procedure Build_Static_Predicate
+ (Typ : Entity_Id;
+ Expr : Node_Id;
+ Nam : Name_Id);
+ -- Given a predicated type Typ, where Typ is a discrete static subtype,
+ -- whose predicate expression is Expr, tests if Expr is a static predicate,
+ -- and if so, builds the predicate range list. Nam is the name of the one
+ -- argument to the predicate function. Occurrences of the type name in the
+ -- predicate expression have been replaced by identifier references to this
+ -- name, which is unique, so any identifier with Chars matching Nam must be
+ -- a reference to the type. If the predicate is non-static, this procedure
+ -- returns doing nothing. If the predicate is static, then the predicate
+ -- list is stored in Static_Predicate (Typ), and the Expr is rewritten as
+ -- a canonicalized membership operation.
+
+ function Get_Alignment_Value (Expr : Node_Id) return Uint;
+ -- Given the expression for an alignment value, returns the corresponding
+ -- Uint value. If the value is inappropriate, then error messages are
+ -- posted as required, and a value of No_Uint is returned.
+
+ function Is_Operational_Item (N : Node_Id) return Boolean;
+ -- A specification for a stream attribute is allowed before the full type
+ -- is declared, as explained in AI-00137 and the corrigendum. Attributes
+ -- that do not specify a representation characteristic are operational
+ -- attributes.
+
+ procedure New_Stream_Subprogram
+ (N : Node_Id;
+ Ent : Entity_Id;
+ Subp : Entity_Id;
+ Nam : TSS_Name_Type);
+ -- Create a subprogram renaming of a given stream attribute to the
+ -- designated subprogram and then in the tagged case, provide this as a
+ -- primitive operation, or in the non-tagged case make an appropriate TSS
+ -- entry. This is more properly an expansion activity than just semantics,
+ -- but the presence of user-defined stream functions for limited types is a
+ -- legality check, which is why this takes place here rather than in
+ -- exp_ch13, where it was previously. Nam indicates the name of the TSS
+ -- function to be generated.
+ --
+ -- To avoid elaboration anomalies with freeze nodes, for untagged types
+ -- we generate both a subprogram declaration and a subprogram renaming
+ -- declaration, so that the attribute specification is handled as a
+ -- renaming_as_body. For tagged types, the specification is one of the
+ -- primitive specs.
+
+ generic
+ with procedure Replace_Type_Reference (N : Node_Id);
+ procedure Replace_Type_References_Generic (N : Node_Id; TName : Name_Id);
+ -- This is used to scan an expression for a predicate or invariant aspect
+ -- replacing occurrences of the name TName (the name of the subtype to
+ -- which the aspect applies) with appropriate references to the parameter
+ -- of the predicate function or invariant procedure. The procedure passed
+ -- as a generic parameter does the actual replacement of node N, which is
+ -- either a simple direct reference to TName, or a selected component that
+ -- represents an appropriately qualified occurrence of TName.
+
+ procedure Set_Biased
+ (E : Entity_Id;
+ N : Node_Id;
+ Msg : String;
+ Biased : Boolean := True);
+ -- If Biased is True, sets Has_Biased_Representation flag for E, and
+ -- outputs a warning message at node N if Warn_On_Biased_Representation is
+ -- is True. This warning inserts the string Msg to describe the construct
+ -- causing biasing.
+
+ ----------------------------------------------
+ -- Table for Validate_Unchecked_Conversions --
+ ----------------------------------------------
+
+ -- The following table collects unchecked conversions for validation.
+ -- Entries are made by Validate_Unchecked_Conversion and then the
+ -- call to Validate_Unchecked_Conversions does the actual error
+ -- checking and posting of warnings. The reason for this delayed
+ -- processing is to take advantage of back-annotations of size and
+ -- alignment values performed by the back end.
+
+ -- Note: the reason we store a Source_Ptr value instead of a Node_Id
+ -- is that by the time Validate_Unchecked_Conversions is called, Sprint
+ -- will already have modified all Sloc values if the -gnatD option is set.
+
+ type UC_Entry is record
+ Eloc : Source_Ptr; -- node used for posting warnings
+ Source : Entity_Id; -- source type for unchecked conversion
+ Target : Entity_Id; -- target type for unchecked conversion
+ end record;
+
+ package Unchecked_Conversions is new Table.Table (
+ Table_Component_Type => UC_Entry,
+ Table_Index_Type => Int,
+ Table_Low_Bound => 1,
+ Table_Initial => 50,
+ Table_Increment => 200,
+ Table_Name => "Unchecked_Conversions");
+
+ ----------------------------------------
+ -- Table for Validate_Address_Clauses --
+ ----------------------------------------
+
+ -- If an address clause has the form
+
+ -- for X'Address use Expr
+
+ -- where Expr is of the form Y'Address or recursively is a reference
+ -- to a constant of either of these forms, and X and Y are entities of
+ -- objects, then if Y has a smaller alignment than X, that merits a
+ -- warning about possible bad alignment. The following table collects
+ -- address clauses of this kind. We put these in a table so that they
+ -- can be checked after the back end has completed annotation of the
+ -- alignments of objects, since we can catch more cases that way.
+
+ type Address_Clause_Check_Record is record
+ N : Node_Id;
+ -- The address clause
+
+ X : Entity_Id;
+ -- The entity of the object overlaying Y
+
+ Y : Entity_Id;
+ -- The entity of the object being overlaid
+
+ Off : Boolean;
+ -- Whether the address is offset within Y
+ end record;
+
+ package Address_Clause_Checks is new Table.Table (
+ Table_Component_Type => Address_Clause_Check_Record,
+ Table_Index_Type => Int,
+ Table_Low_Bound => 1,
+ Table_Initial => 20,
+ Table_Increment => 200,
+ Table_Name => "Address_Clause_Checks");
+
+ -----------------------------------------
+ -- Adjust_Record_For_Reverse_Bit_Order --
+ -----------------------------------------
+
+ procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
+ Comp : Node_Id;
+ CC : Node_Id;
+
+ begin
+ -- Processing depends on version of Ada
+
+ -- For Ada 95, we just renumber bits within a storage unit. We do the
+ -- same for Ada 83 mode, since we recognize pragma Bit_Order in Ada 83,
+ -- and are free to add this extension.
+
+ if Ada_Version < Ada_2005 then
+ Comp := First_Component_Or_Discriminant (R);
+ while Present (Comp) loop
+ CC := Component_Clause (Comp);
+
+ -- If component clause is present, then deal with the non-default
+ -- bit order case for Ada 95 mode.
+
+ -- We only do this processing for the base type, and in fact that
+ -- is important, since otherwise if there are record subtypes, we
+ -- could reverse the bits once for each subtype, which is wrong.
+
+ if Present (CC)
+ and then Ekind (R) = E_Record_Type
+ then
+ declare
+ CFB : constant Uint := Component_Bit_Offset (Comp);
+ CSZ : constant Uint := Esize (Comp);
+ CLC : constant Node_Id := Component_Clause (Comp);
+ Pos : constant Node_Id := Position (CLC);
+ FB : constant Node_Id := First_Bit (CLC);
+
+ Storage_Unit_Offset : constant Uint :=
+ CFB / System_Storage_Unit;
+
+ Start_Bit : constant Uint :=
+ CFB mod System_Storage_Unit;
+
+ begin
+ -- Cases where field goes over storage unit boundary
+
+ if Start_Bit + CSZ > System_Storage_Unit then
+
+ -- Allow multi-byte field but generate warning
+
+ if Start_Bit mod System_Storage_Unit = 0
+ and then CSZ mod System_Storage_Unit = 0
+ then
+ Error_Msg_N
+ ("multi-byte field specified with non-standard"
+ & " Bit_Order?", CLC);
+
+ if Bytes_Big_Endian then
+ Error_Msg_N
+ ("bytes are not reversed "
+ & "(component is big-endian)?", CLC);
+ else
+ Error_Msg_N
+ ("bytes are not reversed "
+ & "(component is little-endian)?", CLC);
+ end if;
+
+ -- Do not allow non-contiguous field
+
+ else
+ Error_Msg_N
+ ("attempt to specify non-contiguous field "
+ & "not permitted", CLC);
+ Error_Msg_N
+ ("\caused by non-standard Bit_Order "
+ & "specified", CLC);
+ Error_Msg_N
+ ("\consider possibility of using "
+ & "Ada 2005 mode here", CLC);
+ end if;
+
+ -- Case where field fits in one storage unit
+
+ else
+ -- Give warning if suspicious component clause
+
+ if Intval (FB) >= System_Storage_Unit
+ and then Warn_On_Reverse_Bit_Order
+ then
+ Error_Msg_N
+ ("?Bit_Order clause does not affect " &
+ "byte ordering", Pos);
+ Error_Msg_Uint_1 :=
+ Intval (Pos) + Intval (FB) /
+ System_Storage_Unit;
+ Error_Msg_N
+ ("?position normalized to ^ before bit " &
+ "order interpreted", Pos);
+ end if;
+
+ -- Here is where we fix up the Component_Bit_Offset value
+ -- to account for the reverse bit order. Some examples of
+ -- what needs to be done are:
+
+ -- First_Bit .. Last_Bit Component_Bit_Offset
+ -- old new old new
+
+ -- 0 .. 0 7 .. 7 0 7
+ -- 0 .. 1 6 .. 7 0 6
+ -- 0 .. 2 5 .. 7 0 5
+ -- 0 .. 7 0 .. 7 0 4
+
+ -- 1 .. 1 6 .. 6 1 6
+ -- 1 .. 4 3 .. 6 1 3
+ -- 4 .. 7 0 .. 3 4 0
+
+ -- The rule is that the first bit is is obtained by
+ -- subtracting the old ending bit from storage_unit - 1.
+
+ Set_Component_Bit_Offset
+ (Comp,
+ (Storage_Unit_Offset * System_Storage_Unit) +
+ (System_Storage_Unit - 1) -
+ (Start_Bit + CSZ - 1));
+
+ Set_Normalized_First_Bit
+ (Comp,
+ Component_Bit_Offset (Comp) mod
+ System_Storage_Unit);
+ end if;
+ end;
+ end if;
+
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+
+ -- For Ada 2005, we do machine scalar processing, as fully described In
+ -- AI-133. This involves gathering all components which start at the
+ -- same byte offset and processing them together. Same approach is still
+ -- valid in later versions including Ada 2012.
+
+ else
+ declare
+ Max_Machine_Scalar_Size : constant Uint :=
+ UI_From_Int
+ (Standard_Long_Long_Integer_Size);
+ -- We use this as the maximum machine scalar size
+
+ Num_CC : Natural;
+ SSU : constant Uint := UI_From_Int (System_Storage_Unit);
+
+ begin
+ -- This first loop through components does two things. First it
+ -- deals with the case of components with component clauses whose
+ -- length is greater than the maximum machine scalar size (either
+ -- accepting them or rejecting as needed). Second, it counts the
+ -- number of components with component clauses whose length does
+ -- not exceed this maximum for later processing.
+
+ Num_CC := 0;
+ Comp := First_Component_Or_Discriminant (R);
+ while Present (Comp) loop
+ CC := Component_Clause (Comp);
+
+ if Present (CC) then
+ declare
+ Fbit : constant Uint :=
+ Static_Integer (First_Bit (CC));
+ Lbit : constant Uint :=
+ Static_Integer (Last_Bit (CC));
+
+ begin
+ -- Case of component with last bit >= max machine scalar
+
+ if Lbit >= Max_Machine_Scalar_Size then
+
+ -- This is allowed only if first bit is zero, and
+ -- last bit + 1 is a multiple of storage unit size.
+
+ if Fbit = 0 and then (Lbit + 1) mod SSU = 0 then
+
+ -- This is the case to give a warning if enabled
+
+ if Warn_On_Reverse_Bit_Order then
+ Error_Msg_N
+ ("multi-byte field specified with "
+ & " non-standard Bit_Order?", CC);
+
+ if Bytes_Big_Endian then
+ Error_Msg_N
+ ("\bytes are not reversed "
+ & "(component is big-endian)?", CC);
+ else
+ Error_Msg_N
+ ("\bytes are not reversed "
+ & "(component is little-endian)?", CC);
+ end if;
+ end if;
+
+ -- Give error message for RM 13.4.1(10) violation
+
+ else
+ Error_Msg_FE
+ ("machine scalar rules not followed for&",
+ First_Bit (CC), Comp);
+
+ Error_Msg_Uint_1 := Lbit;
+ Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
+ Error_Msg_F
+ ("\last bit (^) exceeds maximum machine "
+ & "scalar size (^)",
+ First_Bit (CC));
+
+ if (Lbit + 1) mod SSU /= 0 then
+ Error_Msg_Uint_1 := SSU;
+ Error_Msg_F
+ ("\and is not a multiple of Storage_Unit (^) "
+ & "('R'M 13.4.1(10))",
+ First_Bit (CC));
+
+ else
+ Error_Msg_Uint_1 := Fbit;
+ Error_Msg_F
+ ("\and first bit (^) is non-zero "
+ & "('R'M 13.4.1(10))",
+ First_Bit (CC));
+ end if;
+ end if;
+
+ -- OK case of machine scalar related component clause,
+ -- For now, just count them.
+
+ else
+ Num_CC := Num_CC + 1;
+ end if;
+ end;
+ end if;
+
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+
+ -- We need to sort the component clauses on the basis of the
+ -- Position values in the clause, so we can group clauses with
+ -- the same Position. together to determine the relevant machine
+ -- scalar size.
+
+ Sort_CC : declare
+ Comps : array (0 .. Num_CC) of Entity_Id;
+ -- Array to collect component and discriminant entities. The
+ -- data starts at index 1, the 0'th entry is for the sort
+ -- routine.
+
+ function CP_Lt (Op1, Op2 : Natural) return Boolean;
+ -- Compare routine for Sort
+
+ procedure CP_Move (From : Natural; To : Natural);
+ -- Move routine for Sort
+
+ package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
+
+ Start : Natural;
+ Stop : Natural;
+ -- Start and stop positions in the component list of the set of
+ -- components with the same starting position (that constitute
+ -- components in a single machine scalar).
+
+ MaxL : Uint;
+ -- Maximum last bit value of any component in this set
+
+ MSS : Uint;
+ -- Corresponding machine scalar size
+
+ -----------
+ -- CP_Lt --
+ -----------
+
+ function CP_Lt (Op1, Op2 : Natural) return Boolean is
+ begin
+ return Position (Component_Clause (Comps (Op1))) <
+ Position (Component_Clause (Comps (Op2)));
+ end CP_Lt;
+
+ -------------
+ -- CP_Move --
+ -------------
+
+ procedure CP_Move (From : Natural; To : Natural) is
+ begin
+ Comps (To) := Comps (From);
+ end CP_Move;
+
+ -- Start of processing for Sort_CC
+
+ begin
+ -- Collect the machine scalar relevant component clauses
+
+ Num_CC := 0;
+ Comp := First_Component_Or_Discriminant (R);
+ while Present (Comp) loop
+ declare
+ CC : constant Node_Id := Component_Clause (Comp);
+
+ begin
+ -- Collect only component clauses whose last bit is less
+ -- than machine scalar size. Any component clause whose
+ -- last bit exceeds this value does not take part in
+ -- machine scalar layout considerations. The test for
+ -- Error_Posted makes sure we exclude component clauses
+ -- for which we already posted an error.
+
+ if Present (CC)
+ and then not Error_Posted (Last_Bit (CC))
+ and then Static_Integer (Last_Bit (CC)) <
+ Max_Machine_Scalar_Size
+ then
+ Num_CC := Num_CC + 1;
+ Comps (Num_CC) := Comp;
+ end if;
+ end;
+
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+
+ -- Sort by ascending position number
+
+ Sorting.Sort (Num_CC);
+
+ -- We now have all the components whose size does not exceed
+ -- the max machine scalar value, sorted by starting position.
+ -- In this loop we gather groups of clauses starting at the
+ -- same position, to process them in accordance with AI-133.
+
+ Stop := 0;
+ while Stop < Num_CC loop
+ Start := Stop + 1;
+ Stop := Start;
+ MaxL :=
+ Static_Integer
+ (Last_Bit (Component_Clause (Comps (Start))));
+ while Stop < Num_CC loop
+ if Static_Integer
+ (Position (Component_Clause (Comps (Stop + 1)))) =
+ Static_Integer
+ (Position (Component_Clause (Comps (Stop))))
+ then
+ Stop := Stop + 1;
+ MaxL :=
+ UI_Max
+ (MaxL,
+ Static_Integer
+ (Last_Bit
+ (Component_Clause (Comps (Stop)))));
+ else
+ exit;
+ end if;
+ end loop;
+
+ -- Now we have a group of component clauses from Start to
+ -- Stop whose positions are identical, and MaxL is the
+ -- maximum last bit value of any of these components.
+
+ -- We need to determine the corresponding machine scalar
+ -- size. This loop assumes that machine scalar sizes are
+ -- even, and that each possible machine scalar has twice
+ -- as many bits as the next smaller one.
+
+ MSS := Max_Machine_Scalar_Size;
+ while MSS mod 2 = 0
+ and then (MSS / 2) >= SSU
+ and then (MSS / 2) > MaxL
+ loop
+ MSS := MSS / 2;
+ end loop;
+
+ -- Here is where we fix up the Component_Bit_Offset value
+ -- to account for the reverse bit order. Some examples of
+ -- what needs to be done for the case of a machine scalar
+ -- size of 8 are:
+
+ -- First_Bit .. Last_Bit Component_Bit_Offset
+ -- old new old new
+
+ -- 0 .. 0 7 .. 7 0 7
+ -- 0 .. 1 6 .. 7 0 6
+ -- 0 .. 2 5 .. 7 0 5
+ -- 0 .. 7 0 .. 7 0 4
+
+ -- 1 .. 1 6 .. 6 1 6
+ -- 1 .. 4 3 .. 6 1 3
+ -- 4 .. 7 0 .. 3 4 0
+
+ -- The rule is that the first bit is obtained by subtracting
+ -- the old ending bit from machine scalar size - 1.
+
+ for C in Start .. Stop loop
+ declare
+ Comp : constant Entity_Id := Comps (C);
+ CC : constant Node_Id :=
+ Component_Clause (Comp);
+ LB : constant Uint :=
+ Static_Integer (Last_Bit (CC));
+ NFB : constant Uint := MSS - Uint_1 - LB;
+ NLB : constant Uint := NFB + Esize (Comp) - 1;
+ Pos : constant Uint :=
+ Static_Integer (Position (CC));
+
+ begin
+ if Warn_On_Reverse_Bit_Order then
+ Error_Msg_Uint_1 := MSS;
+ Error_Msg_N
+ ("info: reverse bit order in machine " &
+ "scalar of length^?", First_Bit (CC));
+ Error_Msg_Uint_1 := NFB;
+ Error_Msg_Uint_2 := NLB;
+
+ if Bytes_Big_Endian then
+ Error_Msg_NE
+ ("?\info: big-endian range for "
+ & "component & is ^ .. ^",
+ First_Bit (CC), Comp);
+ else
+ Error_Msg_NE
+ ("?\info: little-endian range "
+ & "for component & is ^ .. ^",
+ First_Bit (CC), Comp);
+ end if;
+ end if;
+
+ Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
+ Set_Normalized_First_Bit (Comp, NFB mod SSU);
+ end;
+ end loop;
+ end loop;
+ end Sort_CC;
+ end;
+ end if;
+ end Adjust_Record_For_Reverse_Bit_Order;
+
+ --------------------------------------
+ -- Alignment_Check_For_Esize_Change --
+ --------------------------------------
+
+ procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
+ begin
+ -- If the alignment is known, and not set by a rep clause, and is
+ -- inconsistent with the size being set, then reset it to unknown,
+ -- we assume in this case that the size overrides the inherited
+ -- alignment, and that the alignment must be recomputed.
+
+ if Known_Alignment (Typ)
+ and then not Has_Alignment_Clause (Typ)
+ and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
+ then
+ Init_Alignment (Typ);
+ end if;
+ end Alignment_Check_For_Esize_Change;
+
+ -----------------------------------
+ -- Analyze_Aspect_Specifications --
+ -----------------------------------
+
+ procedure Analyze_Aspect_Specifications
+ (N : Node_Id;
+ E : Entity_Id;
+ L : List_Id)
+ is
+ Aspect : Node_Id;
+ Aitem : Node_Id;
+ Ent : Node_Id;
+
+ Ins_Node : Node_Id := N;
+ -- Insert pragmas (except Pre/Post/Invariant/Predicate) after this node
+
+ -- The general processing involves building an attribute definition
+ -- clause or a pragma node that corresponds to the access type. Then
+ -- one of two things happens:
+
+ -- If we are required to delay the evaluation of this aspect to the
+ -- freeze point, we preanalyze the relevant argument, and then attach
+ -- the corresponding pragma/attribute definition clause to the aspect
+ -- specification node, which is then placed in the Rep Item chain.
+ -- In this case we mark the entity with the Has_Delayed_Aspects flag,
+ -- and we evaluate the rep item at the freeze point.
+
+ -- If no delay is required, we just insert the pragma or attribute
+ -- after the declaration, and it will get processed by the normal
+ -- circuit. The From_Aspect_Specification flag is set on the pragma
+ -- or attribute definition node in either case to activate special
+ -- processing (e.g. not traversing the list of homonyms for inline).
+
+ Delay_Required : Boolean;
+ -- Set True if delay is required
+
+ begin
+ -- Return if no aspects
+
+ if L = No_List then
+ return;
+ end if;
+
+ -- Return if already analyzed (avoids duplicate calls in some cases
+ -- where type declarations get rewritten and processed twice).
+
+ if Analyzed (N) then
+ return;
+ end if;
+
+ -- Loop through aspects
+
+ Aspect := First (L);
+ while Present (Aspect) loop
+ declare
+ Loc : constant Source_Ptr := Sloc (Aspect);
+ Id : constant Node_Id := Identifier (Aspect);
+ Expr : constant Node_Id := Expression (Aspect);
+ Nam : constant Name_Id := Chars (Id);
+ A_Id : constant Aspect_Id := Get_Aspect_Id (Nam);
+ Anod : Node_Id;
+ T : Entity_Id;
+
+ Eloc : Source_Ptr := Sloc (Expr);
+ -- Source location of expression, modified when we split PPC's
+
+ begin
+ Set_Entity (Aspect, E);
+ Ent := New_Occurrence_Of (E, Sloc (Id));
+
+ -- Check for duplicate aspect. Note that the Comes_From_Source
+ -- test allows duplicate Pre/Post's that we generate internally
+ -- to escape being flagged here.
+
+ Anod := First (L);
+ while Anod /= Aspect loop
+ if Nam = Chars (Identifier (Anod))
+ and then Comes_From_Source (Aspect)
+ then
+ Error_Msg_Name_1 := Nam;
+ Error_Msg_Sloc := Sloc (Anod);
+
+ -- Case of same aspect specified twice
+
+ if Class_Present (Anod) = Class_Present (Aspect) then
+ if not Class_Present (Anod) then
+ Error_Msg_NE
+ ("aspect% for & previously given#",
+ Id, E);
+ else
+ Error_Msg_NE
+ ("aspect `%''Class` for & previously given#",
+ Id, E);
+ end if;
+
+ -- Case of Pre and Pre'Class both specified
+
+ elsif Nam = Name_Pre then
+ if Class_Present (Aspect) then
+ Error_Msg_NE
+ ("aspect `Pre''Class` for & is not allowed here",
+ Id, E);
+ Error_Msg_NE
+ ("\since aspect `Pre` previously given#",
+ Id, E);
+
+ else
+ Error_Msg_NE
+ ("aspect `Pre` for & is not allowed here",
+ Id, E);
+ Error_Msg_NE
+ ("\since aspect `Pre''Class` previously given#",
+ Id, E);
+ end if;
+ end if;
+
+ goto Continue;
+ end if;
+
+ Next (Anod);
+ end loop;
+
+ -- Processing based on specific aspect
+
+ case A_Id is
+
+ -- No_Aspect should be impossible
+
+ when No_Aspect =>
+ raise Program_Error;
+
+ -- Aspects taking an optional boolean argument. For all of
+ -- these we just create a matching pragma and insert it,
+ -- setting flag Cancel_Aspect if the expression is False.
+
+ when Aspect_Ada_2005 |
+ Aspect_Ada_2012 |
+ Aspect_Atomic |
+ Aspect_Atomic_Components |
+ Aspect_Discard_Names |
+ Aspect_Favor_Top_Level |
+ Aspect_Inline |
+ Aspect_Inline_Always |
+ Aspect_No_Return |
+ Aspect_Pack |
+ Aspect_Persistent_BSS |
+ Aspect_Preelaborable_Initialization |
+ Aspect_Pure_Function |
+ Aspect_Shared |
+ Aspect_Suppress_Debug_Info |
+ Aspect_Unchecked_Union |
+ Aspect_Universal_Aliasing |
+ Aspect_Unmodified |
+ Aspect_Unreferenced |
+ Aspect_Unreferenced_Objects |
+ Aspect_Volatile |
+ Aspect_Volatile_Components =>
+
+ -- Build corresponding pragma node
+
+ Aitem :=
+ Make_Pragma (Loc,
+ Pragma_Argument_Associations => New_List (Ent),
+ Pragma_Identifier =>
+ Make_Identifier (Sloc (Id), Chars (Id)));
+
+ -- Deal with missing expression case, delay never needed
+
+ if No (Expr) then
+ Delay_Required := False;
+
+ -- Expression is present
+
+ else
+ Preanalyze_Spec_Expression (Expr, Standard_Boolean);
+
+ -- If preanalysis gives a static expression, we don't
+ -- need to delay (this will happen often in practice).
+
+ if Is_OK_Static_Expression (Expr) then
+ Delay_Required := False;
+
+ if Is_False (Expr_Value (Expr)) then
+ Set_Aspect_Cancel (Aitem);
+ end if;
+
+ -- If we don't get a static expression, then delay, the
+ -- expression may turn out static by freeze time.
+
+ else
+ Delay_Required := True;
+ end if;
+ end if;
+
+ -- Aspects corresponding to attribute definition clauses
+
+ when Aspect_Address |
+ Aspect_Alignment |
+ Aspect_Bit_Order |
+ Aspect_Component_Size |
+ Aspect_External_Tag |
+ Aspect_Machine_Radix |
+ Aspect_Object_Size |
+ Aspect_Size |
+ Aspect_Storage_Pool |
+ Aspect_Storage_Size |
+ Aspect_Stream_Size |
+ Aspect_Value_Size =>
+
+ -- Preanalyze the expression with the appropriate type
+
+ case A_Id is
+ when Aspect_Address =>
+ T := RTE (RE_Address);
+ when Aspect_Bit_Order =>
+ T := RTE (RE_Bit_Order);
+ when Aspect_External_Tag =>
+ T := Standard_String;
+ when Aspect_Storage_Pool =>
+ T := Class_Wide_Type (RTE (RE_Root_Storage_Pool));
+ when others =>
+ T := Any_Integer;
+ end case;
+
+ Preanalyze_Spec_Expression (Expr, T);
+
+ -- Construct the attribute definition clause
+
+ Aitem :=
+ Make_Attribute_Definition_Clause (Loc,
+ Name => Ent,
+ Chars => Chars (Id),
+ Expression => Relocate_Node (Expr));
+
+ -- We do not need a delay if we have a static expression
+
+ if Is_OK_Static_Expression (Expression (Aitem)) then
+ Delay_Required := False;
+
+ -- Here a delay is required
+
+ else
+ Delay_Required := True;
+ end if;
+
+ -- Aspects corresponding to pragmas with two arguments, where
+ -- the first argument is a local name referring to the entity,
+ -- and the second argument is the aspect definition expression.
+
+ when Aspect_Suppress |
+ Aspect_Unsuppress =>
+
+ -- Construct the pragma
+
+ Aitem :=
+ Make_Pragma (Loc,
+ Pragma_Argument_Associations => New_List (
+ New_Occurrence_Of (E, Eloc),
+ Relocate_Node (Expr)),
+ Pragma_Identifier =>
+ Make_Identifier (Sloc (Id), Chars (Id)));
+
+ -- We don't have to play the delay game here, since the only
+ -- values are check names which don't get analyzed anyway.
+
+ Delay_Required := False;
+
+ -- Aspects corresponding to stream routines
+
+ when Aspect_Input |
+ Aspect_Output |
+ Aspect_Read |
+ Aspect_Write =>
+
+ -- Construct the attribute definition clause
+
+ Aitem :=
+ Make_Attribute_Definition_Clause (Loc,
+ Name => Ent,
+ Chars => Chars (Id),
+ Expression => Relocate_Node (Expr));
+
+ -- These are always delayed (typically the subprogram that
+ -- is referenced cannot have been declared yet, since it has
+ -- a reference to the type for which this aspect is defined.
+
+ Delay_Required := True;
+
+ -- Aspects corresponding to pragmas with two arguments, where
+ -- the second argument is a local name referring to the entity,
+ -- and the first argument is the aspect definition expression.
+
+ when Aspect_Warnings =>
+
+ -- Construct the pragma
+
+ Aitem :=
+ Make_Pragma (Loc,
+ Pragma_Argument_Associations => New_List (
+ Relocate_Node (Expr),
+ New_Occurrence_Of (E, Eloc)),
+ Pragma_Identifier =>
+ Make_Identifier (Sloc (Id), Chars (Id)),
+ Class_Present => Class_Present (Aspect));
+
+ -- We don't have to play the delay game here, since the only
+ -- values are check names which don't get analyzed anyway.
+
+ Delay_Required := False;
+
+ -- Aspects Pre/Post generate Precondition/Postcondition pragmas
+ -- with a first argument that is the expression, and a second
+ -- argument that is an informative message if the test fails.
+ -- This is inserted right after the declaration, to get the
+ -- required pragma placement. The processing for the pragmas
+ -- takes care of the required delay.
+
+ when Aspect_Pre | Aspect_Post => declare
+ Pname : Name_Id;
+
+ begin
+ if A_Id = Aspect_Pre then
+ Pname := Name_Precondition;
+ else
+ Pname := Name_Postcondition;
+ end if;
+
+ -- If the expressions is of the form A and then B, then
+ -- we generate separate Pre/Post aspects for the separate
+ -- clauses. Since we allow multiple pragmas, there is no
+ -- problem in allowing multiple Pre/Post aspects internally.
+
+ -- We do not do this for Pre'Class, since we have to put
+ -- these conditions together in a complex OR expression
+
+ if Pname = Name_Postcondition
+ or else not Class_Present (Aspect)
+ then
+ while Nkind (Expr) = N_And_Then loop
+ Insert_After (Aspect,
+ Make_Aspect_Specification (Sloc (Right_Opnd (Expr)),
+ Identifier => Identifier (Aspect),
+ Expression => Relocate_Node (Right_Opnd (Expr)),
+ Class_Present => Class_Present (Aspect),
+ Split_PPC => True));
+ Rewrite (Expr, Relocate_Node (Left_Opnd (Expr)));
+ Eloc := Sloc (Expr);
+ end loop;
+ end if;
+
+ -- Build the precondition/postcondition pragma
+
+ Aitem :=
+ Make_Pragma (Loc,
+ Pragma_Identifier =>
+ Make_Identifier (Sloc (Id), Pname),
+ Class_Present => Class_Present (Aspect),
+ Split_PPC => Split_PPC (Aspect),
+ Pragma_Argument_Associations => New_List (
+ Make_Pragma_Argument_Association (Eloc,
+ Chars => Name_Check,
+ Expression => Relocate_Node (Expr))));
+
+ -- Add message unless exception messages are suppressed
+
+ if not Opt.Exception_Locations_Suppressed then
+ Append_To (Pragma_Argument_Associations (Aitem),
+ Make_Pragma_Argument_Association (Eloc,
+ Chars => Name_Message,
+ Expression =>
+ Make_String_Literal (Eloc,
+ Strval => "failed "
+ & Get_Name_String (Pname)
+ & " from "
+ & Build_Location_String (Eloc))));
+ end if;
+
+ Set_From_Aspect_Specification (Aitem, True);
+
+ -- For Pre/Post cases, insert immediately after the entity
+ -- declaration, since that is the required pragma placement.
+ -- Note that for these aspects, we do not have to worry
+ -- about delay issues, since the pragmas themselves deal
+ -- with delay of visibility for the expression analysis.
+
+ -- If the entity is a library-level subprogram, the pre/
+ -- postconditions must be treated as late pragmas.
+
+ if Nkind (Parent (N)) = N_Compilation_Unit then
+ Add_Global_Declaration (Aitem);
+ else
+ Insert_After (N, Aitem);
+ end if;
+
+ goto Continue;
+ end;
+
+ -- Invariant aspects generate a corresponding pragma with a
+ -- first argument that is the entity, a second argument that is
+ -- the expression and a third argument that is an appropriate
+ -- message. This is inserted right after the declaration, to
+ -- get the required pragma placement. The pragma processing
+ -- takes care of the required delay.
+
+ when Aspect_Invariant =>
+
+ -- Construct the pragma
+
+ Aitem :=
+ Make_Pragma (Loc,
+ Pragma_Argument_Associations =>
+ New_List (Ent, Relocate_Node (Expr)),
+ Class_Present => Class_Present (Aspect),
+ Pragma_Identifier =>
+ Make_Identifier (Sloc (Id), Name_Invariant));
+
+ -- Add message unless exception messages are suppressed
+
+ if not Opt.Exception_Locations_Suppressed then
+ Append_To (Pragma_Argument_Associations (Aitem),
+ Make_Pragma_Argument_Association (Eloc,
+ Chars => Name_Message,
+ Expression =>
+ Make_String_Literal (Eloc,
+ Strval => "failed invariant from "
+ & Build_Location_String (Eloc))));
+ end if;
+
+ Set_From_Aspect_Specification (Aitem, True);
+
+ -- For Invariant case, insert immediately after the entity
+ -- declaration. We do not have to worry about delay issues
+ -- since the pragma processing takes care of this.
+
+ Insert_After (N, Aitem);
+ goto Continue;
+
+ -- Predicate aspects generate a corresponding pragma with a
+ -- first argument that is the entity, and the second argument
+ -- is the expression. This is inserted immediately after the
+ -- declaration, to get the required pragma placement. The
+ -- pragma processing takes care of the required delay.
+
+ when Aspect_Predicate =>
+
+ -- Construct the pragma
+
+ Aitem :=
+ Make_Pragma (Loc,
+ Pragma_Argument_Associations =>
+ New_List (Ent, Relocate_Node (Expr)),
+ Class_Present => Class_Present (Aspect),
+ Pragma_Identifier =>
+ Make_Identifier (Sloc (Id), Name_Predicate));
+
+ Set_From_Aspect_Specification (Aitem, True);
+
+ -- Make sure we have a freeze node (it might otherwise be
+ -- missing in cases like subtype X is Y, and we would not
+ -- have a place to build the predicate function).
+
+ Ensure_Freeze_Node (E);
+
+ -- For Predicate case, insert immediately after the entity
+ -- declaration. We do not have to worry about delay issues
+ -- since the pragma processing takes care of this.
+
+ Insert_After (N, Aitem);
+ goto Continue;
+ end case;
+
+ Set_From_Aspect_Specification (Aitem, True);
+
+ -- If a delay is required, we delay the freeze (not much point in
+ -- delaying the aspect if we don't delay the freeze!). The pragma
+ -- or clause is then attached to the aspect specification which
+ -- is placed in the rep item list.
+
+ if Delay_Required then
+ Ensure_Freeze_Node (E);
+ Set_Is_Delayed_Aspect (Aitem);
+ Set_Has_Delayed_Aspects (E);
+ Set_Aspect_Rep_Item (Aspect, Aitem);
+ Record_Rep_Item (E, Aspect);
+
+ -- If no delay required, insert the pragma/clause in the tree
+
+ else
+ -- For Pre/Post cases, insert immediately after the entity
+ -- declaration, since that is the required pragma placement.
+
+ if A_Id = Aspect_Pre or else A_Id = Aspect_Post then
+ Insert_After (N, Aitem);
+
+ -- For all other cases, insert in sequence
+
+ else
+ Insert_After (Ins_Node, Aitem);
+ Ins_Node := Aitem;
+ end if;
+ end if;
+ end;
+
+ <<Continue>>
+ Next (Aspect);
+ end loop;
+ end Analyze_Aspect_Specifications;
+
+ -----------------------
+ -- Analyze_At_Clause --
+ -----------------------
+
+ -- An at clause is replaced by the corresponding Address attribute
+ -- definition clause that is the preferred approach in Ada 95.
+
+ procedure Analyze_At_Clause (N : Node_Id) is
+ CS : constant Boolean := Comes_From_Source (N);
+
+ begin
+ -- This is an obsolescent feature
+
+ Check_Restriction (No_Obsolescent_Features, N);
+
+ if Warn_On_Obsolescent_Feature then
+ Error_Msg_N
+ ("at clause is an obsolescent feature (RM J.7(2))?", N);
+ Error_Msg_N
+ ("\use address attribute definition clause instead?", N);
+ end if;
+
+ -- Rewrite as address clause
+
+ Rewrite (N,
+ Make_Attribute_Definition_Clause (Sloc (N),
+ Name => Identifier (N),
+ Chars => Name_Address,
+ Expression => Expression (N)));
+
+ -- We preserve Comes_From_Source, since logically the clause still
+ -- comes from the source program even though it is changed in form.
+
+ Set_Comes_From_Source (N, CS);
+
+ -- Analyze rewritten clause
+
+ Analyze_Attribute_Definition_Clause (N);
+ end Analyze_At_Clause;
+
+ -----------------------------------------
+ -- Analyze_Attribute_Definition_Clause --
+ -----------------------------------------
+
+ procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
+ Loc : constant Source_Ptr := Sloc (N);
+ Nam : constant Node_Id := Name (N);
+ Attr : constant Name_Id := Chars (N);
+ Expr : constant Node_Id := Expression (N);
+ Id : constant Attribute_Id := Get_Attribute_Id (Attr);
+ Ent : Entity_Id;
+ U_Ent : Entity_Id;
+
+ FOnly : Boolean := False;
+ -- Reset to True for subtype specific attribute (Alignment, Size)
+ -- and for stream attributes, i.e. those cases where in the call
+ -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
+ -- rules are checked. Note that the case of stream attributes is not
+ -- clear from the RM, but see AI95-00137. Also, the RM seems to
+ -- disallow Storage_Size for derived task types, but that is also
+ -- clearly unintentional.
+
+ procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
+ -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
+ -- definition clauses.
+
+ function Duplicate_Clause return Boolean;
+ -- This routine checks if the aspect for U_Ent being given by attribute
+ -- definition clause N is for an aspect that has already been specified,
+ -- and if so gives an error message. If there is a duplicate, True is
+ -- returned, otherwise if there is no error, False is returned.
+
+ -----------------------------------
+ -- Analyze_Stream_TSS_Definition --
+ -----------------------------------
+
+ procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
+ Subp : Entity_Id := Empty;
+ I : Interp_Index;
+ It : Interp;
+ Pnam : Entity_Id;
+
+ Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
+
+ function Has_Good_Profile (Subp : Entity_Id) return Boolean;
+ -- Return true if the entity is a subprogram with an appropriate
+ -- profile for the attribute being defined.
+
+ ----------------------
+ -- Has_Good_Profile --
+ ----------------------
+
+ function Has_Good_Profile (Subp : Entity_Id) return Boolean is
+ F : Entity_Id;
+ Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
+ Expected_Ekind : constant array (Boolean) of Entity_Kind :=
+ (False => E_Procedure, True => E_Function);
+ Typ : Entity_Id;
+
+ begin
+ if Ekind (Subp) /= Expected_Ekind (Is_Function) then
+ return False;
+ end if;
+
+ F := First_Formal (Subp);
+
+ if No (F)
+ or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
+ or else Designated_Type (Etype (F)) /=
+ Class_Wide_Type (RTE (RE_Root_Stream_Type))
+ then
+ return False;
+ end if;
+
+ if not Is_Function then
+ Next_Formal (F);
+
+ declare
+ Expected_Mode : constant array (Boolean) of Entity_Kind :=
+ (False => E_In_Parameter,
+ True => E_Out_Parameter);
+ begin
+ if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
+ return False;
+ end if;
+ end;
+
+ Typ := Etype (F);
+
+ else
+ Typ := Etype (Subp);
+ end if;
+
+ return Base_Type (Typ) = Base_Type (Ent)
+ and then No (Next_Formal (F));
+ end Has_Good_Profile;
+
+ -- Start of processing for Analyze_Stream_TSS_Definition
+
+ begin
+ FOnly := True;
+
+ if not Is_Type (U_Ent) then
+ Error_Msg_N ("local name must be a subtype", Nam);
+ return;
+ end if;
+
+ Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
+
+ -- If Pnam is present, it can be either inherited from an ancestor
+ -- type (in which case it is legal to redefine it for this type), or
+ -- be a previous definition of the attribute for the same type (in
+ -- which case it is illegal).
+
+ -- In the first case, it will have been analyzed already, and we
+ -- can check that its profile does not match the expected profile
+ -- for a stream attribute of U_Ent. In the second case, either Pnam
+ -- has been analyzed (and has the expected profile), or it has not
+ -- been analyzed yet (case of a type that has not been frozen yet
+ -- and for which the stream attribute has been set using Set_TSS).
+
+ if Present (Pnam)
+ and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
+ then
+ Error_Msg_Sloc := Sloc (Pnam);
+ Error_Msg_Name_1 := Attr;
+ Error_Msg_N ("% attribute already defined #", Nam);
+ return;
+ end if;
+
+ Analyze (Expr);
+
+ if Is_Entity_Name (Expr) then
+ if not Is_Overloaded (Expr) then
+ if Has_Good_Profile (Entity (Expr)) then
+ Subp := Entity (Expr);
+ end if;
+
+ else
+ Get_First_Interp (Expr, I, It);
+ while Present (It.Nam) loop
+ if Has_Good_Profile (It.Nam) then
+ Subp := It.Nam;
+ exit;
+ end if;
+
+ Get_Next_Interp (I, It);
+ end loop;
+ end if;
+ end if;
+
+ if Present (Subp) then
+ if Is_Abstract_Subprogram (Subp) then
+ Error_Msg_N ("stream subprogram must not be abstract", Expr);
+ return;
+ end if;
+
+ Set_Entity (Expr, Subp);
+ Set_Etype (Expr, Etype (Subp));
+
+ New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
+
+ else
+ Error_Msg_Name_1 := Attr;
+ Error_Msg_N ("incorrect expression for% attribute", Expr);
+ end if;
+ end Analyze_Stream_TSS_Definition;
+
+ ----------------------
+ -- Duplicate_Clause --
+ ----------------------
+
+ function Duplicate_Clause return Boolean is
+ A : Node_Id;
+
+ begin
+ -- Nothing to do if this attribute definition clause comes from
+ -- an aspect specification, since we could not be duplicating an
+ -- explicit clause, and we dealt with the case of duplicated aspects
+ -- in Analyze_Aspect_Specifications.
+
+ if From_Aspect_Specification (N) then
+ return False;
+ end if;
+
+ -- Otherwise current clause may duplicate previous clause or a
+ -- previously given aspect specification for the same aspect.
+
+ A := Get_Rep_Item_For_Entity (U_Ent, Chars (N));
+
+ if Present (A) then
+ if Entity (A) = U_Ent then
+ Error_Msg_Name_1 := Chars (N);
+ Error_Msg_Sloc := Sloc (A);
+ Error_Msg_NE ("aspect% for & previously given#", N, U_Ent);
+ return True;
+ end if;
+ end if;
+
+ return False;
+ end Duplicate_Clause;
+
+ -- Start of processing for Analyze_Attribute_Definition_Clause
+
+ begin
+ -- Process Ignore_Rep_Clauses option
+
+ if Ignore_Rep_Clauses then
+ case Id is
+
+ -- The following should be ignored. They do not affect legality
+ -- and may be target dependent. The basic idea of -gnatI is to
+ -- ignore any rep clauses that may be target dependent but do not
+ -- affect legality (except possibly to be rejected because they
+ -- are incompatible with the compilation target).
+
+ when Attribute_Alignment |
+ Attribute_Bit_Order |
+ Attribute_Component_Size |
+ Attribute_Machine_Radix |
+ Attribute_Object_Size |
+ Attribute_Size |
+ Attribute_Small |
+ Attribute_Stream_Size |
+ Attribute_Value_Size =>
+
+ Rewrite (N, Make_Null_Statement (Sloc (N)));
+ return;
+
+ -- The following should not be ignored, because in the first place
+ -- they are reasonably portable, and should not cause problems in
+ -- compiling code from another target, and also they do affect
+ -- legality, e.g. failing to provide a stream attribute for a
+ -- type may make a program illegal.
+
+ when Attribute_External_Tag |
+ Attribute_Input |
+ Attribute_Output |
+ Attribute_Read |
+ Attribute_Storage_Pool |
+ Attribute_Storage_Size |
+ Attribute_Write =>
+ null;
+
+ -- Other cases are errors ("attribute& cannot be set with
+ -- definition clause"), which will be caught below.
+
+ when others =>
+ null;
+ end case;
+ end if;
+
+ Analyze (Nam);
+ Ent := Entity (Nam);
+
+ if Rep_Item_Too_Early (Ent, N) then
+ return;
+ end if;
+
+ -- Rep clause applies to full view of incomplete type or private type if
+ -- we have one (if not, this is a premature use of the type). However,
+ -- certain semantic checks need to be done on the specified entity (i.e.
+ -- the private view), so we save it in Ent.
+
+ if Is_Private_Type (Ent)
+ and then Is_Derived_Type (Ent)
+ and then not Is_Tagged_Type (Ent)
+ and then No (Full_View (Ent))
+ then
+ -- If this is a private type whose completion is a derivation from
+ -- another private type, there is no full view, and the attribute
+ -- belongs to the type itself, not its underlying parent.
+
+ U_Ent := Ent;
+
+ elsif Ekind (Ent) = E_Incomplete_Type then
+
+ -- The attribute applies to the full view, set the entity of the
+ -- attribute definition accordingly.
+
+ Ent := Underlying_Type (Ent);
+ U_Ent := Ent;
+ Set_Entity (Nam, Ent);
+
+ else
+ U_Ent := Underlying_Type (Ent);
+ end if;
+
+ -- Complete other routine error checks
+
+ if Etype (Nam) = Any_Type then
+ return;
+
+ elsif Scope (Ent) /= Current_Scope then
+ Error_Msg_N ("entity must be declared in this scope", Nam);
+ return;
+
+ elsif No (U_Ent) then
+ U_Ent := Ent;
+
+ elsif Is_Type (U_Ent)
+ and then not Is_First_Subtype (U_Ent)
+ and then Id /= Attribute_Object_Size
+ and then Id /= Attribute_Value_Size
+ and then not From_At_Mod (N)
+ then
+ Error_Msg_N ("cannot specify attribute for subtype", Nam);
+ return;
+ end if;
+
+ Set_Entity (N, U_Ent);
+
+ -- Switch on particular attribute
+
+ case Id is
+
+ -------------
+ -- Address --
+ -------------
+
+ -- Address attribute definition clause
+
+ when Attribute_Address => Address : begin
+
+ -- A little error check, catch for X'Address use X'Address;
+
+ if Nkind (Nam) = N_Identifier
+ and then Nkind (Expr) = N_Attribute_Reference
+ and then Attribute_Name (Expr) = Name_Address
+ and then Nkind (Prefix (Expr)) = N_Identifier
+ and then Chars (Nam) = Chars (Prefix (Expr))
+ then
+ Error_Msg_NE
+ ("address for & is self-referencing", Prefix (Expr), Ent);
+ return;
+ end if;
+
+ -- Not that special case, carry on with analysis of expression
+
+ Analyze_And_Resolve (Expr, RTE (RE_Address));
+
+ -- Even when ignoring rep clauses we need to indicate that the
+ -- entity has an address clause and thus it is legal to declare
+ -- it imported.
+
+ if Ignore_Rep_Clauses then
+ if Ekind_In (U_Ent, E_Variable, E_Constant) then
+ Record_Rep_Item (U_Ent, N);
+ end if;
+
+ return;
+ end if;
+
+ if Duplicate_Clause then
+ null;
+
+ -- Case of address clause for subprogram
+
+ elsif Is_Subprogram (U_Ent) then
+ if Has_Homonym (U_Ent) then
+ Error_Msg_N
+ ("address clause cannot be given " &
+ "for overloaded subprogram",
+ Nam);
+ return;
+ end if;
+
+ -- For subprograms, all address clauses are permitted, and we
+ -- mark the subprogram as having a deferred freeze so that Gigi
+ -- will not elaborate it too soon.
+
+ -- Above needs more comments, what is too soon about???
+
+ Set_Has_Delayed_Freeze (U_Ent);
+
+ -- Case of address clause for entry
+
+ elsif Ekind (U_Ent) = E_Entry then
+ if Nkind (Parent (N)) = N_Task_Body then
+ Error_Msg_N
+ ("entry address must be specified in task spec", Nam);
+ return;
+ end if;
+
+ -- For entries, we require a constant address
+
+ Check_Constant_Address_Clause (Expr, U_Ent);
+
+ -- Special checks for task types
+
+ if Is_Task_Type (Scope (U_Ent))
+ and then Comes_From_Source (Scope (U_Ent))
+ then
+ Error_Msg_N
+ ("?entry address declared for entry in task type", N);
+ Error_Msg_N
+ ("\?only one task can be declared of this type", N);
+ end if;
+
+ -- Entry address clauses are obsolescent
+
+ Check_Restriction (No_Obsolescent_Features, N);
+
+ if Warn_On_Obsolescent_Feature then
+ Error_Msg_N
+ ("attaching interrupt to task entry is an " &
+ "obsolescent feature (RM J.7.1)?", N);
+ Error_Msg_N
+ ("\use interrupt procedure instead?", N);
+ end if;
+
+ -- Case of an address clause for a controlled object which we
+ -- consider to be erroneous.
+
+ elsif Is_Controlled (Etype (U_Ent))
+ or else Has_Controlled_Component (Etype (U_Ent))
+ then
+ Error_Msg_NE
+ ("?controlled object& must not be overlaid", Nam, U_Ent);
+ Error_Msg_N
+ ("\?Program_Error will be raised at run time", Nam);
+ Insert_Action (Declaration_Node (U_Ent),
+ Make_Raise_Program_Error (Loc,
+ Reason => PE_Overlaid_Controlled_Object));
+ return;
+
+ -- Case of address clause for a (non-controlled) object
+
+ elsif
+ Ekind (U_Ent) = E_Variable
+ or else
+ Ekind (U_Ent) = E_Constant
+ then
+ declare
+ Expr : constant Node_Id := Expression (N);
+ O_Ent : Entity_Id;
+ Off : Boolean;
+
+ begin
+ -- Exported variables cannot have an address clause, because
+ -- this cancels the effect of the pragma Export.
+
+ if Is_Exported (U_Ent) then
+ Error_Msg_N
+ ("cannot export object with address clause", Nam);
+ return;
+ end if;
+
+ Find_Overlaid_Entity (N, O_Ent, Off);
+
+ -- Overlaying controlled objects is erroneous
+
+ if Present (O_Ent)
+ and then (Has_Controlled_Component (Etype (O_Ent))
+ or else Is_Controlled (Etype (O_Ent)))
+ then
+ Error_Msg_N
+ ("?cannot overlay with controlled object", Expr);
+ Error_Msg_N
+ ("\?Program_Error will be raised at run time", Expr);
+ Insert_Action (Declaration_Node (U_Ent),
+ Make_Raise_Program_Error (Loc,
+ Reason => PE_Overlaid_Controlled_Object));
+ return;
+
+ elsif Present (O_Ent)
+ and then Ekind (U_Ent) = E_Constant
+ and then not Is_Constant_Object (O_Ent)
+ then
+ Error_Msg_N ("constant overlays a variable?", Expr);
+
+ elsif Present (Renamed_Object (U_Ent)) then
+ Error_Msg_N
+ ("address clause not allowed"
+ & " for a renaming declaration (RM 13.1(6))", Nam);
+ return;
+
+ -- Imported variables can have an address clause, but then
+ -- the import is pretty meaningless except to suppress
+ -- initializations, so we do not need such variables to
+ -- be statically allocated (and in fact it causes trouble
+ -- if the address clause is a local value).
+
+ elsif Is_Imported (U_Ent) then
+ Set_Is_Statically_Allocated (U_Ent, False);
+ end if;
+
+ -- We mark a possible modification of a variable with an
+ -- address clause, since it is likely aliasing is occurring.
+
+ Note_Possible_Modification (Nam, Sure => False);
+
+ -- Here we are checking for explicit overlap of one variable
+ -- by another, and if we find this then mark the overlapped
+ -- variable as also being volatile to prevent unwanted
+ -- optimizations. This is a significant pessimization so
+ -- avoid it when there is an offset, i.e. when the object
+ -- is composite; they cannot be optimized easily anyway.
+
+ if Present (O_Ent)
+ and then Is_Object (O_Ent)
+ and then not Off
+ then
+ Set_Treat_As_Volatile (O_Ent);
+ end if;
+
+ -- Legality checks on the address clause for initialized
+ -- objects is deferred until the freeze point, because
+ -- a subsequent pragma might indicate that the object is
+ -- imported and thus not initialized.
+
+ Set_Has_Delayed_Freeze (U_Ent);
+
+ -- If an initialization call has been generated for this
+ -- object, it needs to be deferred to after the freeze node
+ -- we have just now added, otherwise GIGI will see a
+ -- reference to the variable (as actual to the IP call)
+ -- before its definition.
+
+ declare
+ Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
+ begin
+ if Present (Init_Call) then
+ Remove (Init_Call);
+ Append_Freeze_Action (U_Ent, Init_Call);
+ end if;
+ end;
+
+ if Is_Exported (U_Ent) then
+ Error_Msg_N
+ ("& cannot be exported if an address clause is given",
+ Nam);
+ Error_Msg_N
+ ("\define and export a variable " &
+ "that holds its address instead",
+ Nam);
+ end if;
+
+ -- Entity has delayed freeze, so we will generate an
+ -- alignment check at the freeze point unless suppressed.
+
+ if not Range_Checks_Suppressed (U_Ent)
+ and then not Alignment_Checks_Suppressed (U_Ent)
+ then
+ Set_Check_Address_Alignment (N);
+ end if;
+
+ -- Kill the size check code, since we are not allocating
+ -- the variable, it is somewhere else.
+
+ Kill_Size_Check_Code (U_Ent);
+
+ -- If the address clause is of the form:
+
+ -- for Y'Address use X'Address
+
+ -- or
+
+ -- Const : constant Address := X'Address;
+ -- ...
+ -- for Y'Address use Const;
+
+ -- then we make an entry in the table for checking the size
+ -- and alignment of the overlaying variable. We defer this
+ -- check till after code generation to take full advantage
+ -- of the annotation done by the back end. This entry is
+ -- only made if the address clause comes from source.
+ -- If the entity has a generic type, the check will be
+ -- performed in the instance if the actual type justifies
+ -- it, and we do not insert the clause in the table to
+ -- prevent spurious warnings.
+
+ if Address_Clause_Overlay_Warnings
+ and then Comes_From_Source (N)
+ and then Present (O_Ent)
+ and then Is_Object (O_Ent)
+ then
+ if not Is_Generic_Type (Etype (U_Ent)) then
+ Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
+ end if;
+
+ -- If variable overlays a constant view, and we are
+ -- warning on overlays, then mark the variable as
+ -- overlaying a constant (we will give warnings later
+ -- if this variable is assigned).
+
+ if Is_Constant_Object (O_Ent)
+ and then Ekind (U_Ent) = E_Variable
+ then
+ Set_Overlays_Constant (U_Ent);
+ end if;
+ end if;
+ end;
+
+ -- Not a valid entity for an address clause
+
+ else
+ Error_Msg_N ("address cannot be given for &", Nam);
+ end if;
+ end Address;
+
+ ---------------
+ -- Alignment --
+ ---------------
+
+ -- Alignment attribute definition clause
+
+ when Attribute_Alignment => Alignment : declare
+ Align : constant Uint := Get_Alignment_Value (Expr);
+
+ begin
+ FOnly := True;
+
+ if not Is_Type (U_Ent)
+ and then Ekind (U_Ent) /= E_Variable
+ and then Ekind (U_Ent) /= E_Constant
+ then
+ Error_Msg_N ("alignment cannot be given for &", Nam);
+
+ elsif Duplicate_Clause then
+ null;
+
+ elsif Align /= No_Uint then
+ Set_Has_Alignment_Clause (U_Ent);
+ Set_Alignment (U_Ent, Align);
+
+ -- For an array type, U_Ent is the first subtype. In that case,
+ -- also set the alignment of the anonymous base type so that
+ -- other subtypes (such as the itypes for aggregates of the
+ -- type) also receive the expected alignment.
+
+ if Is_Array_Type (U_Ent) then
+ Set_Alignment (Base_Type (U_Ent), Align);
+ end if;
+ end if;
+ end Alignment;
+
+ ---------------
+ -- Bit_Order --
+ ---------------
+
+ -- Bit_Order attribute definition clause
+
+ when Attribute_Bit_Order => Bit_Order : declare
+ begin
+ if not Is_Record_Type (U_Ent) then
+ Error_Msg_N
+ ("Bit_Order can only be defined for record type", Nam);
+
+ elsif Duplicate_Clause then
+ null;
+
+ else
+ Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
+
+ if Etype (Expr) = Any_Type then
+ return;
+
+ elsif not Is_Static_Expression (Expr) then
+ Flag_Non_Static_Expr
+ ("Bit_Order requires static expression!", Expr);
+
+ else
+ if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
+ Set_Reverse_Bit_Order (U_Ent, True);
+ end if;
+ end if;
+ end if;
+ end Bit_Order;
+
+ --------------------
+ -- Component_Size --
+ --------------------
+
+ -- Component_Size attribute definition clause
+
+ when Attribute_Component_Size => Component_Size_Case : declare
+ Csize : constant Uint := Static_Integer (Expr);
+ Ctyp : Entity_Id;
+ Btype : Entity_Id;
+ Biased : Boolean;
+ New_Ctyp : Entity_Id;
+ Decl : Node_Id;
+
+ begin
+ if not Is_Array_Type (U_Ent) then
+ Error_Msg_N ("component size requires array type", Nam);
+ return;
+ end if;
+
+ Btype := Base_Type (U_Ent);
+ Ctyp := Component_Type (Btype);
+
+ if Duplicate_Clause then
+ null;
+
+ elsif Rep_Item_Too_Early (Btype, N) then
+ null;
+
+ elsif Csize /= No_Uint then
+ Check_Size (Expr, Ctyp, Csize, Biased);
+
+ -- For the biased case, build a declaration for a subtype that
+ -- will be used to represent the biased subtype that reflects
+ -- the biased representation of components. We need the subtype
+ -- to get proper conversions on referencing elements of the
+ -- array. Note: component size clauses are ignored in VM mode.
+
+ if VM_Target = No_VM then
+ if Biased then
+ New_Ctyp :=
+ Make_Defining_Identifier (Loc,
+ Chars =>
+ New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
+
+ Decl :=
+ Make_Subtype_Declaration (Loc,
+ Defining_Identifier => New_Ctyp,
+ Subtype_Indication =>
+ New_Occurrence_Of (Component_Type (Btype), Loc));
+
+ Set_Parent (Decl, N);
+ Analyze (Decl, Suppress => All_Checks);
+
+ Set_Has_Delayed_Freeze (New_Ctyp, False);
+ Set_Esize (New_Ctyp, Csize);
+ Set_RM_Size (New_Ctyp, Csize);
+ Init_Alignment (New_Ctyp);
+ Set_Is_Itype (New_Ctyp, True);
+ Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
+
+ Set_Component_Type (Btype, New_Ctyp);
+ Set_Biased (New_Ctyp, N, "component size clause");
+ end if;
+
+ Set_Component_Size (Btype, Csize);
+
+ -- For VM case, we ignore component size clauses
+
+ else
+ -- Give a warning unless we are in GNAT mode, in which case
+ -- the warning is suppressed since it is not useful.
+
+ if not GNAT_Mode then
+ Error_Msg_N
+ ("?component size ignored in this configuration", N);
+ end if;
+ end if;
+
+ -- Deal with warning on overridden size
+
+ if Warn_On_Overridden_Size
+ and then Has_Size_Clause (Ctyp)
+ and then RM_Size (Ctyp) /= Csize
+ then
+ Error_Msg_NE
+ ("?component size overrides size clause for&",
+ N, Ctyp);
+ end if;
+
+ Set_Has_Component_Size_Clause (Btype, True);
+ Set_Has_Non_Standard_Rep (Btype, True);
+ end if;
+ end Component_Size_Case;
+
+ ------------------
+ -- External_Tag --
+ ------------------
+
+ when Attribute_External_Tag => External_Tag :
+ begin
+ if not Is_Tagged_Type (U_Ent) then
+ Error_Msg_N ("should be a tagged type", Nam);
+ end if;
+
+ if Duplicate_Clause then
+ null;
+
+ else
+ Analyze_And_Resolve (Expr, Standard_String);
+
+ if not Is_Static_Expression (Expr) then
+ Flag_Non_Static_Expr
+ ("static string required for tag name!", Nam);
+ end if;
+
+ if VM_Target = No_VM then
+ Set_Has_External_Tag_Rep_Clause (U_Ent);
+ else
+ Error_Msg_Name_1 := Attr;
+ Error_Msg_N
+ ("% attribute unsupported in this configuration", Nam);
+ end if;
+
+ if not Is_Library_Level_Entity (U_Ent) then
+ Error_Msg_NE
+ ("?non-unique external tag supplied for &", N, U_Ent);
+ Error_Msg_N
+ ("?\same external tag applies to all subprogram calls", N);
+ Error_Msg_N
+ ("?\corresponding internal tag cannot be obtained", N);
+ end if;
+ end if;
+ end External_Tag;
+
+ -----------
+ -- Input --
+ -----------
+
+ when Attribute_Input =>
+ Analyze_Stream_TSS_Definition (TSS_Stream_Input);
+ Set_Has_Specified_Stream_Input (Ent);
+
+ -------------------
+ -- Machine_Radix --
+ -------------------
+
+ -- Machine radix attribute definition clause
+
+ when Attribute_Machine_Radix => Machine_Radix : declare
+ Radix : constant Uint := Static_Integer (Expr);
+
+ begin
+ if not Is_Decimal_Fixed_Point_Type (U_Ent) then
+ Error_Msg_N ("decimal fixed-point type expected for &", Nam);
+
+ elsif Duplicate_Clause then
+ null;
+
+ elsif Radix /= No_Uint then
+ Set_Has_Machine_Radix_Clause (U_Ent);
+ Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
+
+ if Radix = 2 then
+ null;
+ elsif Radix = 10 then
+ Set_Machine_Radix_10 (U_Ent);
+ else
+ Error_Msg_N ("machine radix value must be 2 or 10", Expr);
+ end if;
+ end if;
+ end Machine_Radix;
+
+ -----------------
+ -- Object_Size --
+ -----------------
+
+ -- Object_Size attribute definition clause
+
+ when Attribute_Object_Size => Object_Size : declare
+ Size : constant Uint := Static_Integer (Expr);
+
+ Biased : Boolean;
+ pragma Warnings (Off, Biased);
+
+ begin
+ if not Is_Type (U_Ent) then
+ Error_Msg_N ("Object_Size cannot be given for &", Nam);
+
+ elsif Duplicate_Clause then
+ null;
+
+ else
+ Check_Size (Expr, U_Ent, Size, Biased);
+
+ if Size /= 8
+ and then
+ Size /= 16
+ and then
+ Size /= 32
+ and then
+ UI_Mod (Size, 64) /= 0
+ then
+ Error_Msg_N
+ ("Object_Size must be 8, 16, 32, or multiple of 64",
+ Expr);
+ end if;
+
+ Set_Esize (U_Ent, Size);
+ Set_Has_Object_Size_Clause (U_Ent);
+ Alignment_Check_For_Esize_Change (U_Ent);
+ end if;
+ end Object_Size;
+
+ ------------
+ -- Output --
+ ------------
+
+ when Attribute_Output =>
+ Analyze_Stream_TSS_Definition (TSS_Stream_Output);
+ Set_Has_Specified_Stream_Output (Ent);
+
+ ----------
+ -- Read --
+ ----------
+
+ when Attribute_Read =>
+ Analyze_Stream_TSS_Definition (TSS_Stream_Read);
+ Set_Has_Specified_Stream_Read (Ent);
+
+ ----------
+ -- Size --
+ ----------
+
+ -- Size attribute definition clause
+
+ when Attribute_Size => Size : declare
+ Size : constant Uint := Static_Integer (Expr);
+ Etyp : Entity_Id;
+ Biased : Boolean;
+
+ begin
+ FOnly := True;
+
+ if Duplicate_Clause then
+ null;
+
+ elsif not Is_Type (U_Ent)
+ and then Ekind (U_Ent) /= E_Variable
+ and then Ekind (U_Ent) /= E_Constant
+ then
+ Error_Msg_N ("size cannot be given for &", Nam);
+
+ elsif Is_Array_Type (U_Ent)
+ and then not Is_Constrained (U_Ent)
+ then
+ Error_Msg_N
+ ("size cannot be given for unconstrained array", Nam);
+
+ elsif Size /= No_Uint then
+
+ if VM_Target /= No_VM and then not GNAT_Mode then
+
+ -- Size clause is not handled properly on VM targets.
+ -- Display a warning unless we are in GNAT mode, in which
+ -- case this is useless.
+
+ Error_Msg_N
+ ("?size clauses are ignored in this configuration", N);
+ end if;
+
+ if Is_Type (U_Ent) then
+ Etyp := U_Ent;
+ else
+ Etyp := Etype (U_Ent);
+ end if;
+
+ -- Check size, note that Gigi is in charge of checking that the
+ -- size of an array or record type is OK. Also we do not check
+ -- the size in the ordinary fixed-point case, since it is too
+ -- early to do so (there may be subsequent small clause that
+ -- affects the size). We can check the size if a small clause
+ -- has already been given.
+
+ if not Is_Ordinary_Fixed_Point_Type (U_Ent)
+ or else Has_Small_Clause (U_Ent)
+ then
+ Check_Size (Expr, Etyp, Size, Biased);
+ Set_Biased (U_Ent, N, "size clause", Biased);
+ end if;
+
+ -- For types set RM_Size and Esize if possible
+
+ if Is_Type (U_Ent) then
+ Set_RM_Size (U_Ent, Size);
+
+ -- For scalar types, increase Object_Size to power of 2, but
+ -- not less than a storage unit in any case (i.e., normally
+ -- this means it will be byte addressable).
+
+ if Is_Scalar_Type (U_Ent) then
+ if Size <= System_Storage_Unit then
+ Init_Esize (U_Ent, System_Storage_Unit);
+ elsif Size <= 16 then
+ Init_Esize (U_Ent, 16);
+ elsif Size <= 32 then
+ Init_Esize (U_Ent, 32);
+ else
+ Set_Esize (U_Ent, (Size + 63) / 64 * 64);
+ end if;
+
+ -- For all other types, object size = value size. The
+ -- backend will adjust as needed.
+
+ else
+ Set_Esize (U_Ent, Size);
+ end if;
+
+ Alignment_Check_For_Esize_Change (U_Ent);
+
+ -- For objects, set Esize only
+
+ else
+ if Is_Elementary_Type (Etyp) then
+ if Size /= System_Storage_Unit
+ and then
+ Size /= System_Storage_Unit * 2
+ and then
+ Size /= System_Storage_Unit * 4
+ and then
+ Size /= System_Storage_Unit * 8
+ then
+ Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
+ Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
+ Error_Msg_N
+ ("size for primitive object must be a power of 2"
+ & " in the range ^-^", N);
+ end if;
+ end if;
+
+ Set_Esize (U_Ent, Size);
+ end if;
+
+ Set_Has_Size_Clause (U_Ent);
+ end if;
+ end Size;
+
+ -----------
+ -- Small --
+ -----------
+
+ -- Small attribute definition clause
+
+ when Attribute_Small => Small : declare
+ Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
+ Small : Ureal;
+
+ begin
+ Analyze_And_Resolve (Expr, Any_Real);
+
+ if Etype (Expr) = Any_Type then
+ return;
+
+ elsif not Is_Static_Expression (Expr) then
+ Flag_Non_Static_Expr
+ ("small requires static expression!", Expr);
+ return;
+
+ else
+ Small := Expr_Value_R (Expr);
+
+ if Small <= Ureal_0 then
+ Error_Msg_N ("small value must be greater than zero", Expr);
+ return;
+ end if;
+
+ end if;
+
+ if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
+ Error_Msg_N
+ ("small requires an ordinary fixed point type", Nam);
+
+ elsif Has_Small_Clause (U_Ent) then
+ Error_Msg_N ("small already given for &", Nam);
+
+ elsif Small > Delta_Value (U_Ent) then
+ Error_Msg_N
+ ("small value must not be greater then delta value", Nam);
+
+ else
+ Set_Small_Value (U_Ent, Small);
+ Set_Small_Value (Implicit_Base, Small);
+ Set_Has_Small_Clause (U_Ent);
+ Set_Has_Small_Clause (Implicit_Base);
+ Set_Has_Non_Standard_Rep (Implicit_Base);
+ end if;
+ end Small;
+
+ ------------------
+ -- Storage_Pool --
+ ------------------
+
+ -- Storage_Pool attribute definition clause
+
+ when Attribute_Storage_Pool => Storage_Pool : declare
+ Pool : Entity_Id;
+ T : Entity_Id;
+
+ begin
+ if Ekind (U_Ent) = E_Access_Subprogram_Type then
+ Error_Msg_N
+ ("storage pool cannot be given for access-to-subprogram type",
+ Nam);
+ return;
+
+ elsif not
+ Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
+ then
+ Error_Msg_N
+ ("storage pool can only be given for access types", Nam);
+ return;
+
+ elsif Is_Derived_Type (U_Ent) then
+ Error_Msg_N
+ ("storage pool cannot be given for a derived access type",
+ Nam);
+
+ elsif Duplicate_Clause then
+ return;
+
+ elsif Present (Associated_Storage_Pool (U_Ent)) then
+ Error_Msg_N ("storage pool already given for &", Nam);
+ return;
+ end if;
+
+ Analyze_And_Resolve
+ (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
+
+ if not Denotes_Variable (Expr) then
+ Error_Msg_N ("storage pool must be a variable", Expr);
+ return;
+ end if;
+
+ if Nkind (Expr) = N_Type_Conversion then
+ T := Etype (Expression (Expr));
+ else
+ T := Etype (Expr);
+ end if;
+
+ -- The Stack_Bounded_Pool is used internally for implementing
+ -- access types with a Storage_Size. Since it only work
+ -- properly when used on one specific type, we need to check
+ -- that it is not hijacked improperly:
+ -- type T is access Integer;
+ -- for T'Storage_Size use n;
+ -- type Q is access Float;
+ -- for Q'Storage_Size use T'Storage_Size; -- incorrect
+
+ if RTE_Available (RE_Stack_Bounded_Pool)
+ and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
+ then
+ Error_Msg_N ("non-shareable internal Pool", Expr);
+ return;
+ end if;
+
+ -- If the argument is a name that is not an entity name, then
+ -- we construct a renaming operation to define an entity of
+ -- type storage pool.
+
+ if not Is_Entity_Name (Expr)
+ and then Is_Object_Reference (Expr)
+ then
+ Pool := Make_Temporary (Loc, 'P', Expr);
+
+ declare
+ Rnode : constant Node_Id :=
+ Make_Object_Renaming_Declaration (Loc,
+ Defining_Identifier => Pool,
+ Subtype_Mark =>
+ New_Occurrence_Of (Etype (Expr), Loc),
+ Name => Expr);
+
+ begin
+ Insert_Before (N, Rnode);
+ Analyze (Rnode);
+ Set_Associated_Storage_Pool (U_Ent, Pool);
+ end;
+
+ elsif Is_Entity_Name (Expr) then
+ Pool := Entity (Expr);
+
+ -- If pool is a renamed object, get original one. This can
+ -- happen with an explicit renaming, and within instances.
+
+ while Present (Renamed_Object (Pool))
+ and then Is_Entity_Name (Renamed_Object (Pool))
+ loop
+ Pool := Entity (Renamed_Object (Pool));
+ end loop;
+
+ if Present (Renamed_Object (Pool))
+ and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
+ and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
+ then
+ Pool := Entity (Expression (Renamed_Object (Pool)));
+ end if;
+
+ Set_Associated_Storage_Pool (U_Ent, Pool);
+
+ elsif Nkind (Expr) = N_Type_Conversion
+ and then Is_Entity_Name (Expression (Expr))
+ and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
+ then
+ Pool := Entity (Expression (Expr));
+ Set_Associated_Storage_Pool (U_Ent, Pool);
+
+ else
+ Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
+ return;
+ end if;
+ end Storage_Pool;
+
+ ------------------
+ -- Storage_Size --
+ ------------------
+
+ -- Storage_Size attribute definition clause
+
+ when Attribute_Storage_Size => Storage_Size : declare
+ Btype : constant Entity_Id := Base_Type (U_Ent);
+ Sprag : Node_Id;
+
+ begin
+ if Is_Task_Type (U_Ent) then
+ Check_Restriction (No_Obsolescent_Features, N);
+
+ if Warn_On_Obsolescent_Feature then
+ Error_Msg_N
+ ("storage size clause for task is an " &
+ "obsolescent feature (RM J.9)?", N);
+ Error_Msg_N ("\use Storage_Size pragma instead?", N);
+ end if;
+
+ FOnly := True;
+ end if;
+
+ if not Is_Access_Type (U_Ent)
+ and then Ekind (U_Ent) /= E_Task_Type
+ then
+ Error_Msg_N ("storage size cannot be given for &", Nam);
+
+ elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
+ Error_Msg_N
+ ("storage size cannot be given for a derived access type",
+ Nam);
+
+ elsif Duplicate_Clause then
+ null;
+
+ else
+ Analyze_And_Resolve (Expr, Any_Integer);
+
+ if Is_Access_Type (U_Ent) then
+ if Present (Associated_Storage_Pool (U_Ent)) then
+ Error_Msg_N ("storage pool already given for &", Nam);
+ return;
+ end if;
+
+ if Is_OK_Static_Expression (Expr)
+ and then Expr_Value (Expr) = 0
+ then
+ Set_No_Pool_Assigned (Btype);
+ end if;
+
+ else -- Is_Task_Type (U_Ent)
+ Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
+
+ if Present (Sprag) then
+ Error_Msg_Sloc := Sloc (Sprag);
+ Error_Msg_N
+ ("Storage_Size already specified#", Nam);
+ return;
+ end if;
+ end if;
+
+ Set_Has_Storage_Size_Clause (Btype);
+ end if;
+ end Storage_Size;
+
+ -----------------
+ -- Stream_Size --
+ -----------------
+
+ when Attribute_Stream_Size => Stream_Size : declare
+ Size : constant Uint := Static_Integer (Expr);
+
+ begin
+ if Ada_Version <= Ada_95 then
+ Check_Restriction (No_Implementation_Attributes, N);
+ end if;
+
+ if Duplicate_Clause then
+ null;
+
+ elsif Is_Elementary_Type (U_Ent) then
+ if Size /= System_Storage_Unit
+ and then
+ Size /= System_Storage_Unit * 2
+ and then
+ Size /= System_Storage_Unit * 4
+ and then
+ Size /= System_Storage_Unit * 8
+ then
+ Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
+ Error_Msg_N
+ ("stream size for elementary type must be a"
+ & " power of 2 and at least ^", N);
+
+ elsif RM_Size (U_Ent) > Size then
+ Error_Msg_Uint_1 := RM_Size (U_Ent);
+ Error_Msg_N
+ ("stream size for elementary type must be a"
+ & " power of 2 and at least ^", N);
+ end if;
+
+ Set_Has_Stream_Size_Clause (U_Ent);
+
+ else
+ Error_Msg_N ("Stream_Size cannot be given for &", Nam);
+ end if;
+ end Stream_Size;
+
+ ----------------
+ -- Value_Size --
+ ----------------
+
+ -- Value_Size attribute definition clause
+
+ when Attribute_Value_Size => Value_Size : declare
+ Size : constant Uint := Static_Integer (Expr);
+ Biased : Boolean;
+
+ begin
+ if not Is_Type (U_Ent) then
+ Error_Msg_N ("Value_Size cannot be given for &", Nam);
+
+ elsif Duplicate_Clause then
+ null;
+
+ elsif Is_Array_Type (U_Ent)
+ and then not Is_Constrained (U_Ent)
+ then
+ Error_Msg_N
+ ("Value_Size cannot be given for unconstrained array", Nam);
+
+ else
+ if Is_Elementary_Type (U_Ent) then
+ Check_Size (Expr, U_Ent, Size, Biased);
+ Set_Biased (U_Ent, N, "value size clause", Biased);
+ end if;
+
+ Set_RM_Size (U_Ent, Size);
+ end if;
+ end Value_Size;
+
+ -----------
+ -- Write --
+ -----------
+
+ when Attribute_Write =>
+ Analyze_Stream_TSS_Definition (TSS_Stream_Write);
+ Set_Has_Specified_Stream_Write (Ent);
+
+ -- All other attributes cannot be set
+
+ when others =>
+ Error_Msg_N
+ ("attribute& cannot be set with definition clause", N);
+ end case;
+
+ -- The test for the type being frozen must be performed after
+ -- any expression the clause has been analyzed since the expression
+ -- itself might cause freezing that makes the clause illegal.
+
+ if Rep_Item_Too_Late (U_Ent, N, FOnly) then
+ return;
+ end if;
+ end Analyze_Attribute_Definition_Clause;
+
+ ----------------------------
+ -- Analyze_Code_Statement --
+ ----------------------------
+
+ procedure Analyze_Code_Statement (N : Node_Id) is
+ HSS : constant Node_Id := Parent (N);
+ SBody : constant Node_Id := Parent (HSS);
+ Subp : constant Entity_Id := Current_Scope;
+ Stmt : Node_Id;
+ Decl : Node_Id;
+ StmtO : Node_Id;
+ DeclO : Node_Id;
+
+ begin
+ -- Analyze and check we get right type, note that this implements the
+ -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
+ -- is the only way that Asm_Insn could possibly be visible.
+
+ Analyze_And_Resolve (Expression (N));
+
+ if Etype (Expression (N)) = Any_Type then
+ return;
+ elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
+ Error_Msg_N ("incorrect type for code statement", N);
+ return;
+ end if;
+
+ Check_Code_Statement (N);
+
+ -- Make sure we appear in the handled statement sequence of a
+ -- subprogram (RM 13.8(3)).
+
+ if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
+ or else Nkind (SBody) /= N_Subprogram_Body
+ then
+ Error_Msg_N
+ ("code statement can only appear in body of subprogram", N);
+ return;
+ end if;
+
+ -- Do remaining checks (RM 13.8(3)) if not already done
+
+ if not Is_Machine_Code_Subprogram (Subp) then
+ Set_Is_Machine_Code_Subprogram (Subp);
+
+ -- No exception handlers allowed
+
+ if Present (Exception_Handlers (HSS)) then
+ Error_Msg_N
+ ("exception handlers not permitted in machine code subprogram",
+ First (Exception_Handlers (HSS)));
+ end if;
+
+ -- No declarations other than use clauses and pragmas (we allow
+ -- certain internally generated declarations as well).
+
+ Decl := First (Declarations (SBody));
+ while Present (Decl) loop
+ DeclO := Original_Node (Decl);
+ if Comes_From_Source (DeclO)
+ and not Nkind_In (DeclO, N_Pragma,
+ N_Use_Package_Clause,
+ N_Use_Type_Clause,
+ N_Implicit_Label_Declaration)
+ then
+ Error_Msg_N
+ ("this declaration not allowed in machine code subprogram",
+ DeclO);
+ end if;
+
+ Next (Decl);
+ end loop;
+
+ -- No statements other than code statements, pragmas, and labels.
+ -- Again we allow certain internally generated statements.
+
+ Stmt := First (Statements (HSS));
+ while Present (Stmt) loop
+ StmtO := Original_Node (Stmt);
+ if Comes_From_Source (StmtO)
+ and then not Nkind_In (StmtO, N_Pragma,
+ N_Label,
+ N_Code_Statement)
+ then
+ Error_Msg_N
+ ("this statement is not allowed in machine code subprogram",
+ StmtO);
+ end if;
+
+ Next (Stmt);
+ end loop;
+ end if;
+ end Analyze_Code_Statement;
+
+ -----------------------------------------------
+ -- Analyze_Enumeration_Representation_Clause --
+ -----------------------------------------------
+
+ procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
+ Ident : constant Node_Id := Identifier (N);
+ Aggr : constant Node_Id := Array_Aggregate (N);
+ Enumtype : Entity_Id;
+ Elit : Entity_Id;
+ Expr : Node_Id;
+ Assoc : Node_Id;
+ Choice : Node_Id;
+ Val : Uint;
+ Err : Boolean := False;
+
+ Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
+ Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
+ -- Allowed range of universal integer (= allowed range of enum lit vals)
+
+ Min : Uint;
+ Max : Uint;
+ -- Minimum and maximum values of entries
+
+ Max_Node : Node_Id;
+ -- Pointer to node for literal providing max value
+
+ begin
+ if Ignore_Rep_Clauses then
+ return;
+ end if;
+
+ -- First some basic error checks
+
+ Find_Type (Ident);
+ Enumtype := Entity (Ident);
+
+ if Enumtype = Any_Type
+ or else Rep_Item_Too_Early (Enumtype, N)
+ then
+ return;
+ else
+ Enumtype := Underlying_Type (Enumtype);
+ end if;
+
+ if not Is_Enumeration_Type (Enumtype) then
+ Error_Msg_NE
+ ("enumeration type required, found}",
+ Ident, First_Subtype (Enumtype));
+ return;
+ end if;
+
+ -- Ignore rep clause on generic actual type. This will already have
+ -- been flagged on the template as an error, and this is the safest
+ -- way to ensure we don't get a junk cascaded message in the instance.
+
+ if Is_Generic_Actual_Type (Enumtype) then
+ return;
+
+ -- Type must be in current scope
+
+ elsif Scope (Enumtype) /= Current_Scope then
+ Error_Msg_N ("type must be declared in this scope", Ident);
+ return;
+
+ -- Type must be a first subtype
+
+ elsif not Is_First_Subtype (Enumtype) then
+ Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
+ return;
+
+ -- Ignore duplicate rep clause
+
+ elsif Has_Enumeration_Rep_Clause (Enumtype) then
+ Error_Msg_N ("duplicate enumeration rep clause ignored", N);
+ return;
+
+ -- Don't allow rep clause for standard [wide_[wide_]]character
+
+ elsif Is_Standard_Character_Type (Enumtype) then
+ Error_Msg_N ("enumeration rep clause not allowed for this type", N);
+ return;
+
+ -- Check that the expression is a proper aggregate (no parentheses)
+
+ elsif Paren_Count (Aggr) /= 0 then
+ Error_Msg
+ ("extra parentheses surrounding aggregate not allowed",
+ First_Sloc (Aggr));
+ return;
+
+ -- All tests passed, so set rep clause in place
+
+ else
+ Set_Has_Enumeration_Rep_Clause (Enumtype);
+ Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
+ end if;
+
+ -- Now we process the aggregate. Note that we don't use the normal
+ -- aggregate code for this purpose, because we don't want any of the
+ -- normal expansion activities, and a number of special semantic
+ -- rules apply (including the component type being any integer type)
+
+ Elit := First_Literal (Enumtype);
+
+ -- First the positional entries if any
+
+ if Present (Expressions (Aggr)) then
+ Expr := First (Expressions (Aggr));
+ while Present (Expr) loop
+ if No (Elit) then
+ Error_Msg_N ("too many entries in aggregate", Expr);
+ return;
+ end if;
+
+ Val := Static_Integer (Expr);
+
+ -- Err signals that we found some incorrect entries processing
+ -- the list. The final checks for completeness and ordering are
+ -- skipped in this case.
+
+ if Val = No_Uint then
+ Err := True;
+ elsif Val < Lo or else Hi < Val then
+ Error_Msg_N ("value outside permitted range", Expr);
+ Err := True;
+ end if;
+
+ Set_Enumeration_Rep (Elit, Val);
+ Set_Enumeration_Rep_Expr (Elit, Expr);
+ Next (Expr);
+ Next (Elit);
+ end loop;
+ end if;
+
+ -- Now process the named entries if present
+
+ if Present (Component_Associations (Aggr)) then
+ Assoc := First (Component_Associations (Aggr));
+ while Present (Assoc) loop
+ Choice := First (Choices (Assoc));
+
+ if Present (Next (Choice)) then
+ Error_Msg_N
+ ("multiple choice not allowed here", Next (Choice));
+ Err := True;
+ end if;
+
+ if Nkind (Choice) = N_Others_Choice then
+ Error_Msg_N ("others choice not allowed here", Choice);
+ Err := True;
+
+ elsif Nkind (Choice) = N_Range then
+ -- ??? should allow zero/one element range here
+ Error_Msg_N ("range not allowed here", Choice);
+ Err := True;
+
+ else
+ Analyze_And_Resolve (Choice, Enumtype);
+
+ if Is_Entity_Name (Choice)
+ and then Is_Type (Entity (Choice))
+ then
+ Error_Msg_N ("subtype name not allowed here", Choice);
+ Err := True;
+ -- ??? should allow static subtype with zero/one entry
+
+ elsif Etype (Choice) = Base_Type (Enumtype) then
+ if not Is_Static_Expression (Choice) then
+ Flag_Non_Static_Expr
+ ("non-static expression used for choice!", Choice);
+ Err := True;
+
+ else
+ Elit := Expr_Value_E (Choice);
+
+ if Present (Enumeration_Rep_Expr (Elit)) then
+ Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
+ Error_Msg_NE
+ ("representation for& previously given#",
+ Choice, Elit);
+ Err := True;
+ end if;
+
+ Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
+
+ Expr := Expression (Assoc);
+ Val := Static_Integer (Expr);
+
+ if Val = No_Uint then
+ Err := True;
+
+ elsif Val < Lo or else Hi < Val then
+ Error_Msg_N ("value outside permitted range", Expr);
+ Err := True;
+ end if;
+
+ Set_Enumeration_Rep (Elit, Val);
+ end if;
+ end if;
+ end if;
+
+ Next (Assoc);
+ end loop;
+ end if;
+
+ -- Aggregate is fully processed. Now we check that a full set of
+ -- representations was given, and that they are in range and in order.
+ -- These checks are only done if no other errors occurred.
+
+ if not Err then
+ Min := No_Uint;
+ Max := No_Uint;
+
+ Elit := First_Literal (Enumtype);
+ while Present (Elit) loop
+ if No (Enumeration_Rep_Expr (Elit)) then
+ Error_Msg_NE ("missing representation for&!", N, Elit);
+
+ else
+ Val := Enumeration_Rep (Elit);
+
+ if Min = No_Uint then
+ Min := Val;
+ end if;
+
+ if Val /= No_Uint then
+ if Max /= No_Uint and then Val <= Max then
+ Error_Msg_NE
+ ("enumeration value for& not ordered!",
+ Enumeration_Rep_Expr (Elit), Elit);
+ end if;
+
+ Max_Node := Enumeration_Rep_Expr (Elit);
+ Max := Val;
+ end if;
+
+ -- If there is at least one literal whose representation is not
+ -- equal to the Pos value, then note that this enumeration type
+ -- has a non-standard representation.
+
+ if Val /= Enumeration_Pos (Elit) then
+ Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
+ end if;
+ end if;
+
+ Next (Elit);
+ end loop;
+
+ -- Now set proper size information
+
+ declare
+ Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
+
+ begin
+ if Has_Size_Clause (Enumtype) then
+
+ -- All OK, if size is OK now
+
+ if RM_Size (Enumtype) >= Minsize then
+ null;
+
+ else
+ -- Try if we can get by with biasing
+
+ Minsize :=
+ UI_From_Int (Minimum_Size (Enumtype, Biased => True));
+
+ -- Error message if even biasing does not work
+
+ if RM_Size (Enumtype) < Minsize then
+ Error_Msg_Uint_1 := RM_Size (Enumtype);
+ Error_Msg_Uint_2 := Max;
+ Error_Msg_N
+ ("previously given size (^) is too small "
+ & "for this value (^)", Max_Node);
+
+ -- If biasing worked, indicate that we now have biased rep
+
+ else
+ Set_Biased
+ (Enumtype, Size_Clause (Enumtype), "size clause");
+ end if;
+ end if;
+
+ else
+ Set_RM_Size (Enumtype, Minsize);
+ Set_Enum_Esize (Enumtype);
+ end if;
+
+ Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
+ Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
+ Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
+ end;
+ end if;
+
+ -- We repeat the too late test in case it froze itself!
+
+ if Rep_Item_Too_Late (Enumtype, N) then
+ null;
+ end if;
+ end Analyze_Enumeration_Representation_Clause;
+
+ ----------------------------
+ -- Analyze_Free_Statement --
+ ----------------------------
+
+ procedure Analyze_Free_Statement (N : Node_Id) is
+ begin
+ Analyze (Expression (N));
+ end Analyze_Free_Statement;
+
+ ---------------------------
+ -- Analyze_Freeze_Entity --
+ ---------------------------
+
+ procedure Analyze_Freeze_Entity (N : Node_Id) is
+ E : constant Entity_Id := Entity (N);
+
+ begin
+ -- Remember that we are processing a freezing entity. Required to
+ -- ensure correct decoration of internal entities associated with
+ -- interfaces (see New_Overloaded_Entity).
+
+ Inside_Freezing_Actions := Inside_Freezing_Actions + 1;
+
+ -- For tagged types covering interfaces add internal entities that link
+ -- the primitives of the interfaces with the primitives that cover them.
+ -- Note: These entities were originally generated only when generating
+ -- code because their main purpose was to provide support to initialize
+ -- the secondary dispatch tables. They are now generated also when
+ -- compiling with no code generation to provide ASIS the relationship
+ -- between interface primitives and tagged type primitives. They are
+ -- also used to locate primitives covering interfaces when processing
+ -- generics (see Derive_Subprograms).
+
+ if Ada_Version >= Ada_2005
+ and then Ekind (E) = E_Record_Type
+ and then Is_Tagged_Type (E)
+ and then not Is_Interface (E)
+ and then Has_Interfaces (E)
+ then
+ -- This would be a good common place to call the routine that checks
+ -- overriding of interface primitives (and thus factorize calls to
+ -- Check_Abstract_Overriding located at different contexts in the
+ -- compiler). However, this is not possible because it causes
+ -- spurious errors in case of late overriding.
+
+ Add_Internal_Interface_Entities (E);
+ end if;
+
+ -- Check CPP types
+
+ if Ekind (E) = E_Record_Type
+ and then Is_CPP_Class (E)
+ and then Is_Tagged_Type (E)
+ and then Tagged_Type_Expansion
+ and then Expander_Active
+ then
+ if CPP_Num_Prims (E) = 0 then
+
+ -- If the CPP type has user defined components then it must import
+ -- primitives from C++. This is required because if the C++ class
+ -- has no primitives then the C++ compiler does not added the _tag
+ -- component to the type.
+
+ pragma Assert (Chars (First_Entity (E)) = Name_uTag);
+
+ if First_Entity (E) /= Last_Entity (E) then
+ Error_Msg_N
+ ("?'C'P'P type must import at least one primitive from C++",
+ E);
+ end if;
+ end if;
+
+ -- Check that all its primitives are abstract or imported from C++.
+ -- Check also availability of the C++ constructor.
+
+ declare
+ Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
+ Elmt : Elmt_Id;
+ Error_Reported : Boolean := False;
+ Prim : Node_Id;
+
+ begin
+ Elmt := First_Elmt (Primitive_Operations (E));
+ while Present (Elmt) loop
+ Prim := Node (Elmt);
+
+ if Comes_From_Source (Prim) then
+ if Is_Abstract_Subprogram (Prim) then
+ null;
+
+ elsif not Is_Imported (Prim)
+ or else Convention (Prim) /= Convention_CPP
+ then
+ Error_Msg_N
+ ("?primitives of 'C'P'P types must be imported from C++"
+ & " or abstract", Prim);
+
+ elsif not Has_Constructors
+ and then not Error_Reported
+ then
+ Error_Msg_Name_1 := Chars (E);
+ Error_Msg_N
+ ("?'C'P'P constructor required for type %", Prim);
+ Error_Reported := True;
+ end if;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+ end;
+ end if;
+
+ Inside_Freezing_Actions := Inside_Freezing_Actions - 1;
+
+ -- If we have a type with predicates, build predicate function
+
+ if Is_Type (E) and then Has_Predicates (E) then
+ Build_Predicate_Function (E, N);
+ end if;
+ end Analyze_Freeze_Entity;
+
+ ------------------------------------------
+ -- Analyze_Record_Representation_Clause --
+ ------------------------------------------
+
+ -- Note: we check as much as we can here, but we can't do any checks
+ -- based on the position values (e.g. overlap checks) until freeze time
+ -- because especially in Ada 2005 (machine scalar mode), the processing
+ -- for non-standard bit order can substantially change the positions.
+ -- See procedure Check_Record_Representation_Clause (called from Freeze)
+ -- for the remainder of this processing.
+
+ procedure Analyze_Record_Representation_Clause (N : Node_Id) is
+ Ident : constant Node_Id := Identifier (N);
+ Biased : Boolean;
+ CC : Node_Id;
+ Comp : Entity_Id;
+ Fbit : Uint;
+ Hbit : Uint := Uint_0;
+ Lbit : Uint;
+ Ocomp : Entity_Id;
+ Posit : Uint;
+ Rectype : Entity_Id;
+
+ CR_Pragma : Node_Id := Empty;
+ -- Points to N_Pragma node if Complete_Representation pragma present
+
+ begin
+ if Ignore_Rep_Clauses then
+ return;
+ end if;
+
+ Find_Type (Ident);
+ Rectype := Entity (Ident);
+
+ if Rectype = Any_Type
+ or else Rep_Item_Too_Early (Rectype, N)
+ then
+ return;
+ else
+ Rectype := Underlying_Type (Rectype);
+ end if;
+
+ -- First some basic error checks
+
+ if not Is_Record_Type (Rectype) then
+ Error_Msg_NE
+ ("record type required, found}", Ident, First_Subtype (Rectype));
+ return;
+
+ elsif Scope (Rectype) /= Current_Scope then
+ Error_Msg_N ("type must be declared in this scope", N);
+ return;
+
+ elsif not Is_First_Subtype (Rectype) then
+ Error_Msg_N ("cannot give record rep clause for subtype", N);
+ return;
+
+ elsif Has_Record_Rep_Clause (Rectype) then
+ Error_Msg_N ("duplicate record rep clause ignored", N);
+ return;
+
+ elsif Rep_Item_Too_Late (Rectype, N) then
+ return;
+ end if;
+
+ if Present (Mod_Clause (N)) then
+ declare
+ Loc : constant Source_Ptr := Sloc (N);
+ M : constant Node_Id := Mod_Clause (N);
+ P : constant List_Id := Pragmas_Before (M);
+ AtM_Nod : Node_Id;
+
+ Mod_Val : Uint;
+ pragma Warnings (Off, Mod_Val);
+
+ begin
+ Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
+
+ if Warn_On_Obsolescent_Feature then
+ Error_Msg_N
+ ("mod clause is an obsolescent feature (RM J.8)?", N);
+ Error_Msg_N
+ ("\use alignment attribute definition clause instead?", N);
+ end if;
+
+ if Present (P) then
+ Analyze_List (P);
+ end if;
+
+ -- In ASIS_Mode mode, expansion is disabled, but we must convert
+ -- the Mod clause into an alignment clause anyway, so that the
+ -- back-end can compute and back-annotate properly the size and
+ -- alignment of types that may include this record.
+
+ -- This seems dubious, this destroys the source tree in a manner
+ -- not detectable by ASIS ???
+
+ if Operating_Mode = Check_Semantics
+ and then ASIS_Mode
+ then
+ AtM_Nod :=
+ Make_Attribute_Definition_Clause (Loc,
+ Name => New_Reference_To (Base_Type (Rectype), Loc),
+ Chars => Name_Alignment,
+ Expression => Relocate_Node (Expression (M)));
+
+ Set_From_At_Mod (AtM_Nod);
+ Insert_After (N, AtM_Nod);
+ Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
+ Set_Mod_Clause (N, Empty);
+
+ else
+ -- Get the alignment value to perform error checking
+
+ Mod_Val := Get_Alignment_Value (Expression (M));
+ end if;
+ end;
+ end if;
+
+ -- For untagged types, clear any existing component clauses for the
+ -- type. If the type is derived, this is what allows us to override
+ -- a rep clause for the parent. For type extensions, the representation
+ -- of the inherited components is inherited, so we want to keep previous
+ -- component clauses for completeness.
+
+ if not Is_Tagged_Type (Rectype) then
+ Comp := First_Component_Or_Discriminant (Rectype);
+ while Present (Comp) loop
+ Set_Component_Clause (Comp, Empty);
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+ end if;
+
+ -- All done if no component clauses
+
+ CC := First (Component_Clauses (N));
+
+ if No (CC) then
+ return;
+ end if;
+
+ -- A representation like this applies to the base type
+
+ Set_Has_Record_Rep_Clause (Base_Type (Rectype));
+ Set_Has_Non_Standard_Rep (Base_Type (Rectype));
+ Set_Has_Specified_Layout (Base_Type (Rectype));
+
+ -- Process the component clauses
+
+ while Present (CC) loop
+
+ -- Pragma
+
+ if Nkind (CC) = N_Pragma then
+ Analyze (CC);
+
+ -- The only pragma of interest is Complete_Representation
+
+ if Pragma_Name (CC) = Name_Complete_Representation then
+ CR_Pragma := CC;
+ end if;
+
+ -- Processing for real component clause
+
+ else
+ Posit := Static_Integer (Position (CC));
+ Fbit := Static_Integer (First_Bit (CC));
+ Lbit := Static_Integer (Last_Bit (CC));
+
+ if Posit /= No_Uint
+ and then Fbit /= No_Uint
+ and then Lbit /= No_Uint
+ then
+ if Posit < 0 then
+ Error_Msg_N
+ ("position cannot be negative", Position (CC));
+
+ elsif Fbit < 0 then
+ Error_Msg_N
+ ("first bit cannot be negative", First_Bit (CC));
+
+ -- The Last_Bit specified in a component clause must not be
+ -- less than the First_Bit minus one (RM-13.5.1(10)).
+
+ elsif Lbit < Fbit - 1 then
+ Error_Msg_N
+ ("last bit cannot be less than first bit minus one",
+ Last_Bit (CC));
+
+ -- Values look OK, so find the corresponding record component
+ -- Even though the syntax allows an attribute reference for
+ -- implementation-defined components, GNAT does not allow the
+ -- tag to get an explicit position.
+
+ elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
+ if Attribute_Name (Component_Name (CC)) = Name_Tag then
+ Error_Msg_N ("position of tag cannot be specified", CC);
+ else
+ Error_Msg_N ("illegal component name", CC);
+ end if;
+
+ else
+ Comp := First_Entity (Rectype);
+ while Present (Comp) loop
+ exit when Chars (Comp) = Chars (Component_Name (CC));
+ Next_Entity (Comp);
+ end loop;
+
+ if No (Comp) then
+
+ -- Maybe component of base type that is absent from
+ -- statically constrained first subtype.
+
+ Comp := First_Entity (Base_Type (Rectype));
+ while Present (Comp) loop
+ exit when Chars (Comp) = Chars (Component_Name (CC));
+ Next_Entity (Comp);
+ end loop;
+ end if;
+
+ if No (Comp) then
+ Error_Msg_N
+ ("component clause is for non-existent field", CC);
+
+ -- Ada 2012 (AI05-0026): Any name that denotes a
+ -- discriminant of an object of an unchecked union type
+ -- shall not occur within a record_representation_clause.
+
+ -- The general restriction of using record rep clauses on
+ -- Unchecked_Union types has now been lifted. Since it is
+ -- possible to introduce a record rep clause which mentions
+ -- the discriminant of an Unchecked_Union in non-Ada 2012
+ -- code, this check is applied to all versions of the
+ -- language.
+
+ elsif Ekind (Comp) = E_Discriminant
+ and then Is_Unchecked_Union (Rectype)
+ then
+ Error_Msg_N
+ ("cannot reference discriminant of Unchecked_Union",
+ Component_Name (CC));
+
+ elsif Present (Component_Clause (Comp)) then
+
+ -- Diagnose duplicate rep clause, or check consistency
+ -- if this is an inherited component. In a double fault,
+ -- there may be a duplicate inconsistent clause for an
+ -- inherited component.
+
+ if Scope (Original_Record_Component (Comp)) = Rectype
+ or else Parent (Component_Clause (Comp)) = N
+ then
+ Error_Msg_Sloc := Sloc (Component_Clause (Comp));
+ Error_Msg_N ("component clause previously given#", CC);
+
+ else
+ declare
+ Rep1 : constant Node_Id := Component_Clause (Comp);
+ begin
+ if Intval (Position (Rep1)) /=
+ Intval (Position (CC))
+ or else Intval (First_Bit (Rep1)) /=
+ Intval (First_Bit (CC))
+ or else Intval (Last_Bit (Rep1)) /=
+ Intval (Last_Bit (CC))
+ then
+ Error_Msg_N ("component clause inconsistent "
+ & "with representation of ancestor", CC);
+ elsif Warn_On_Redundant_Constructs then
+ Error_Msg_N ("?redundant component clause "
+ & "for inherited component!", CC);
+ end if;
+ end;
+ end if;
+
+ -- Normal case where this is the first component clause we
+ -- have seen for this entity, so set it up properly.
+
+ else
+ -- Make reference for field in record rep clause and set
+ -- appropriate entity field in the field identifier.
+
+ Generate_Reference
+ (Comp, Component_Name (CC), Set_Ref => False);
+ Set_Entity (Component_Name (CC), Comp);
+
+ -- Update Fbit and Lbit to the actual bit number
+
+ Fbit := Fbit + UI_From_Int (SSU) * Posit;
+ Lbit := Lbit + UI_From_Int (SSU) * Posit;
+
+ if Has_Size_Clause (Rectype)
+ and then Esize (Rectype) <= Lbit
+ then
+ Error_Msg_N
+ ("bit number out of range of specified size",
+ Last_Bit (CC));
+ else
+ Set_Component_Clause (Comp, CC);
+ Set_Component_Bit_Offset (Comp, Fbit);
+ Set_Esize (Comp, 1 + (Lbit - Fbit));
+ Set_Normalized_First_Bit (Comp, Fbit mod SSU);
+ Set_Normalized_Position (Comp, Fbit / SSU);
+
+ if Warn_On_Overridden_Size
+ and then Has_Size_Clause (Etype (Comp))
+ and then RM_Size (Etype (Comp)) /= Esize (Comp)
+ then
+ Error_Msg_NE
+ ("?component size overrides size clause for&",
+ Component_Name (CC), Etype (Comp));
+ end if;
+
+ -- This information is also set in the corresponding
+ -- component of the base type, found by accessing the
+ -- Original_Record_Component link if it is present.
+
+ Ocomp := Original_Record_Component (Comp);
+
+ if Hbit < Lbit then
+ Hbit := Lbit;
+ end if;
+
+ Check_Size
+ (Component_Name (CC),
+ Etype (Comp),
+ Esize (Comp),
+ Biased);
+
+ Set_Biased
+ (Comp, First_Node (CC), "component clause", Biased);
+
+ if Present (Ocomp) then
+ Set_Component_Clause (Ocomp, CC);
+ Set_Component_Bit_Offset (Ocomp, Fbit);
+ Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
+ Set_Normalized_Position (Ocomp, Fbit / SSU);
+ Set_Esize (Ocomp, 1 + (Lbit - Fbit));
+
+ Set_Normalized_Position_Max
+ (Ocomp, Normalized_Position (Ocomp));
+
+ -- Note: we don't use Set_Biased here, because we
+ -- already gave a warning above if needed, and we
+ -- would get a duplicate for the same name here.
+
+ Set_Has_Biased_Representation
+ (Ocomp, Has_Biased_Representation (Comp));
+ end if;
+
+ if Esize (Comp) < 0 then
+ Error_Msg_N ("component size is negative", CC);
+ end if;
+ end if;
+ end if;
+ end if;
+ end if;
+ end if;
+
+ Next (CC);
+ end loop;
+
+ -- Check missing components if Complete_Representation pragma appeared
+
+ if Present (CR_Pragma) then
+ Comp := First_Component_Or_Discriminant (Rectype);
+ while Present (Comp) loop
+ if No (Component_Clause (Comp)) then
+ Error_Msg_NE
+ ("missing component clause for &", CR_Pragma, Comp);
+ end if;
+
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+
+ -- If no Complete_Representation pragma, warn if missing components
+
+ elsif Warn_On_Unrepped_Components then
+ declare
+ Num_Repped_Components : Nat := 0;
+ Num_Unrepped_Components : Nat := 0;
+
+ begin
+ -- First count number of repped and unrepped components
+
+ Comp := First_Component_Or_Discriminant (Rectype);
+ while Present (Comp) loop
+ if Present (Component_Clause (Comp)) then
+ Num_Repped_Components := Num_Repped_Components + 1;
+ else
+ Num_Unrepped_Components := Num_Unrepped_Components + 1;
+ end if;
+
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+
+ -- We are only interested in the case where there is at least one
+ -- unrepped component, and at least half the components have rep
+ -- clauses. We figure that if less than half have them, then the
+ -- partial rep clause is really intentional. If the component
+ -- type has no underlying type set at this point (as for a generic
+ -- formal type), we don't know enough to give a warning on the
+ -- component.
+
+ if Num_Unrepped_Components > 0
+ and then Num_Unrepped_Components < Num_Repped_Components
+ then
+ Comp := First_Component_Or_Discriminant (Rectype);
+ while Present (Comp) loop
+ if No (Component_Clause (Comp))
+ and then Comes_From_Source (Comp)
+ and then Present (Underlying_Type (Etype (Comp)))
+ and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
+ or else Size_Known_At_Compile_Time
+ (Underlying_Type (Etype (Comp))))
+ and then not Has_Warnings_Off (Rectype)
+ then
+ Error_Msg_Sloc := Sloc (Comp);
+ Error_Msg_NE
+ ("?no component clause given for & declared #",
+ N, Comp);
+ end if;
+
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+ end if;
+ end;
+ end if;
+ end Analyze_Record_Representation_Clause;
+
+ -------------------------------
+ -- Build_Invariant_Procedure --
+ -------------------------------
+
+ -- The procedure that is constructed here has the form
+
+ -- procedure typInvariant (Ixxx : typ) is
+ -- begin
+ -- pragma Check (Invariant, exp, "failed invariant from xxx");
+ -- pragma Check (Invariant, exp, "failed invariant from xxx");
+ -- ...
+ -- pragma Check (Invariant, exp, "failed inherited invariant from xxx");
+ -- ...
+ -- end typInvariant;
+
+ procedure Build_Invariant_Procedure (Typ : Entity_Id; N : Node_Id) is
+ Loc : constant Source_Ptr := Sloc (Typ);
+ Stmts : List_Id;
+ Spec : Node_Id;
+ SId : Entity_Id;
+ PDecl : Node_Id;
+ PBody : Node_Id;
+
+ Visible_Decls : constant List_Id := Visible_Declarations (N);
+ Private_Decls : constant List_Id := Private_Declarations (N);
+
+ procedure Add_Invariants (T : Entity_Id; Inherit : Boolean);
+ -- Appends statements to Stmts for any invariants in the rep item chain
+ -- of the given type. If Inherit is False, then we only process entries
+ -- on the chain for the type Typ. If Inherit is True, then we ignore any
+ -- Invariant aspects, but we process all Invariant'Class aspects, adding
+ -- "inherited" to the exception message and generating an informational
+ -- message about the inheritance of an invariant.
+
+ Object_Name : constant Name_Id := New_Internal_Name ('I');
+ -- Name for argument of invariant procedure
+
+ Object_Entity : constant Node_Id :=
+ Make_Defining_Identifier (Loc, Object_Name);
+ -- The procedure declaration entity for the argument
+
+ --------------------
+ -- Add_Invariants --
+ --------------------
+
+ procedure Add_Invariants (T : Entity_Id; Inherit : Boolean) is
+ Ritem : Node_Id;
+ Arg1 : Node_Id;
+ Arg2 : Node_Id;
+ Arg3 : Node_Id;
+ Exp : Node_Id;
+ Loc : Source_Ptr;
+ Assoc : List_Id;
+ Str : String_Id;
+
+ procedure Replace_Type_Reference (N : Node_Id);
+ -- Replace a single occurrence N of the subtype name with a reference
+ -- to the formal of the predicate function. N can be an identifier
+ -- referencing the subtype, or a selected component, representing an
+ -- appropriately qualified occurrence of the subtype name.
+
+ procedure Replace_Type_References is
+ new Replace_Type_References_Generic (Replace_Type_Reference);
+ -- Traverse an expression replacing all occurrences of the subtype
+ -- name with appropriate references to the object that is the formal
+ -- parameter of the predicate function. Note that we must ensure
+ -- that the type and entity information is properly set in the
+ -- replacement node, since we will do a Preanalyze call of this
+ -- expression without proper visibility of the procedure argument.
+
+ ----------------------------
+ -- Replace_Type_Reference --
+ ----------------------------
+
+ procedure Replace_Type_Reference (N : Node_Id) is
+ begin
+ -- Invariant'Class, replace with T'Class (obj)
+
+ if Class_Present (Ritem) then
+ Rewrite (N,
+ Make_Type_Conversion (Loc,
+ Subtype_Mark =>
+ Make_Attribute_Reference (Loc,
+ Prefix => New_Occurrence_Of (T, Loc),
+ Attribute_Name => Name_Class),
+ Expression => Make_Identifier (Loc, Object_Name)));
+
+ Set_Entity (Expression (N), Object_Entity);
+ Set_Etype (Expression (N), Typ);
+
+ -- Invariant, replace with obj
+
+ else
+ Rewrite (N, Make_Identifier (Loc, Object_Name));
+ Set_Entity (N, Object_Entity);
+ Set_Etype (N, Typ);
+ end if;
+ end Replace_Type_Reference;
+
+ -- Start of processing for Add_Invariants
+
+ begin
+ Ritem := First_Rep_Item (T);
+ while Present (Ritem) loop
+ if Nkind (Ritem) = N_Pragma
+ and then Pragma_Name (Ritem) = Name_Invariant
+ then
+ Arg1 := First (Pragma_Argument_Associations (Ritem));
+ Arg2 := Next (Arg1);
+ Arg3 := Next (Arg2);
+
+ Arg1 := Get_Pragma_Arg (Arg1);
+ Arg2 := Get_Pragma_Arg (Arg2);
+
+ -- For Inherit case, ignore Invariant, process only Class case
+
+ if Inherit then
+ if not Class_Present (Ritem) then
+ goto Continue;
+ end if;
+
+ -- For Inherit false, process only item for right type
+
+ else
+ if Entity (Arg1) /= Typ then
+ goto Continue;
+ end if;
+ end if;
+
+ if No (Stmts) then
+ Stmts := Empty_List;
+ end if;
+
+ Exp := New_Copy_Tree (Arg2);
+ Loc := Sloc (Exp);
+
+ -- We need to replace any occurrences of the name of the type
+ -- with references to the object, converted to type'Class in
+ -- the case of Invariant'Class aspects.
+
+ Replace_Type_References (Exp, Chars (T));
+
+ -- Now we need to preanalyze the expression to properly capture
+ -- the visibility in the visible part. The expression will not
+ -- be analyzed for real until the body is analyzed, but that is
+ -- at the end of the private part and has the wrong visibility.
+
+ Set_Parent (Exp, N);
+ Preanalyze_Spec_Expression (Exp, Standard_Boolean);
+
+ -- Build first two arguments for Check pragma
+
+ Assoc := New_List (
+ Make_Pragma_Argument_Association (Loc,
+ Expression => Make_Identifier (Loc, Name_Invariant)),
+ Make_Pragma_Argument_Association (Loc, Expression => Exp));
+
+ -- Add message if present in Invariant pragma
+
+ if Present (Arg3) then
+ Str := Strval (Get_Pragma_Arg (Arg3));
+
+ -- If inherited case, and message starts "failed invariant",
+ -- change it to be "failed inherited invariant".
+
+ if Inherit then
+ String_To_Name_Buffer (Str);
+
+ if Name_Buffer (1 .. 16) = "failed invariant" then
+ Insert_Str_In_Name_Buffer ("inherited ", 8);
+ Str := String_From_Name_Buffer;
+ end if;
+ end if;
+
+ Append_To (Assoc,
+ Make_Pragma_Argument_Association (Loc,
+ Expression => Make_String_Literal (Loc, Str)));
+ end if;
+
+ -- Add Check pragma to list of statements
+
+ Append_To (Stmts,
+ Make_Pragma (Loc,
+ Pragma_Identifier =>
+ Make_Identifier (Loc, Name_Check),
+ Pragma_Argument_Associations => Assoc));
+
+ -- If Inherited case and option enabled, output info msg. Note
+ -- that we know this is a case of Invariant'Class.
+
+ if Inherit and Opt.List_Inherited_Aspects then
+ Error_Msg_Sloc := Sloc (Ritem);
+ Error_Msg_N
+ ("?info: & inherits `Invariant''Class` aspect from #",
+ Typ);
+ end if;
+ end if;
+
+ <<Continue>>
+ Next_Rep_Item (Ritem);
+ end loop;
+ end Add_Invariants;
+
+ -- Start of processing for Build_Invariant_Procedure
+
+ begin
+ Stmts := No_List;
+ PDecl := Empty;
+ PBody := Empty;
+ Set_Etype (Object_Entity, Typ);
+
+ -- Add invariants for the current type
+
+ Add_Invariants (Typ, Inherit => False);
+
+ -- Add invariants for parent types
+
+ declare
+ Current_Typ : Entity_Id;
+ Parent_Typ : Entity_Id;
+
+ begin
+ Current_Typ := Typ;
+ loop
+ Parent_Typ := Etype (Current_Typ);
+
+ if Is_Private_Type (Parent_Typ)
+ and then Present (Full_View (Base_Type (Parent_Typ)))
+ then
+ Parent_Typ := Full_View (Base_Type (Parent_Typ));
+ end if;
+
+ exit when Parent_Typ = Current_Typ;
+
+ Current_Typ := Parent_Typ;
+ Add_Invariants (Current_Typ, Inherit => True);
+ end loop;
+ end;
+
+ -- Build the procedure if we generated at least one Check pragma
+
+ if Stmts /= No_List then
+
+ -- Build procedure declaration
+
+ SId :=
+ Make_Defining_Identifier (Loc,
+ Chars => New_External_Name (Chars (Typ), "Invariant"));
+ Set_Has_Invariants (SId);
+ Set_Invariant_Procedure (Typ, SId);
+
+ Spec :=
+ Make_Procedure_Specification (Loc,
+ Defining_Unit_Name => SId,
+ Parameter_Specifications => New_List (
+ Make_Parameter_Specification (Loc,
+ Defining_Identifier => Object_Entity,
+ Parameter_Type => New_Occurrence_Of (Typ, Loc))));
+
+ PDecl := Make_Subprogram_Declaration (Loc, Specification => Spec);
+
+ -- Build procedure body
+
+ SId :=
+ Make_Defining_Identifier (Loc,
+ Chars => New_External_Name (Chars (Typ), "Invariant"));
+
+ Spec :=
+ Make_Procedure_Specification (Loc,
+ Defining_Unit_Name => SId,
+ Parameter_Specifications => New_List (
+ Make_Parameter_Specification (Loc,
+ Defining_Identifier =>
+ Make_Defining_Identifier (Loc, Object_Name),
+ Parameter_Type => New_Occurrence_Of (Typ, Loc))));
+
+ PBody :=
+ Make_Subprogram_Body (Loc,
+ Specification => Spec,
+ Declarations => Empty_List,
+ Handled_Statement_Sequence =>
+ Make_Handled_Sequence_Of_Statements (Loc,
+ Statements => Stmts));
+
+ -- Insert procedure declaration and spec at the appropriate points.
+ -- Skip this if there are no private declarations (that's an error
+ -- that will be diagnosed elsewhere, and there is no point in having
+ -- an invariant procedure set if the full declaration is missing).
+
+ if Present (Private_Decls) then
+
+ -- The spec goes at the end of visible declarations, but they have
+ -- already been analyzed, so we need to explicitly do the analyze.
+
+ Append_To (Visible_Decls, PDecl);
+ Analyze (PDecl);
+
+ -- The body goes at the end of the private declarations, which we
+ -- have not analyzed yet, so we do not need to perform an explicit
+ -- analyze call. We skip this if there are no private declarations
+ -- (this is an error that will be caught elsewhere);
+
+ Append_To (Private_Decls, PBody);
+ end if;
+ end if;
+ end Build_Invariant_Procedure;
+
+ ------------------------------
+ -- Build_Predicate_Function --
+ ------------------------------
+
+ -- The procedure that is constructed here has the form
+
+ -- function typPredicate (Ixxx : typ) return Boolean is
+ -- begin
+ -- return
+ -- exp1 and then exp2 and then ...
+ -- and then typ1Predicate (typ1 (Ixxx))
+ -- and then typ2Predicate (typ2 (Ixxx))
+ -- and then ...;
+ -- end typPredicate;
+
+ -- Here exp1, and exp2 are expressions from Predicate pragmas. Note that
+ -- this is the point at which these expressions get analyzed, providing the
+ -- required delay, and typ1, typ2, are entities from which predicates are
+ -- inherited. Note that we do NOT generate Check pragmas, that's because we
+ -- use this function even if checks are off, e.g. for membership tests.
+
+ procedure Build_Predicate_Function (Typ : Entity_Id; N : Node_Id) is
+ Loc : constant Source_Ptr := Sloc (Typ);
+ Spec : Node_Id;
+ SId : Entity_Id;
+ FDecl : Node_Id;
+ FBody : Node_Id;
+
+ Expr : Node_Id;
+ -- This is the expression for the return statement in the function. It
+ -- is build by connecting the component predicates with AND THEN.
+
+ procedure Add_Call (T : Entity_Id);
+ -- Includes a call to the predicate function for type T in Expr if T
+ -- has predicates and Predicate_Function (T) is non-empty.
+
+ procedure Add_Predicates;
+ -- Appends expressions for any Predicate pragmas in the rep item chain
+ -- Typ to Expr. Note that we look only at items for this exact entity.
+ -- Inheritance of predicates for the parent type is done by calling the
+ -- Predicate_Function of the parent type, using Add_Call above.
+
+ Object_Name : constant Name_Id := New_Internal_Name ('I');
+ -- Name for argument of Predicate procedure
+
+ --------------
+ -- Add_Call --
+ --------------
+
+ procedure Add_Call (T : Entity_Id) is
+ Exp : Node_Id;
+
+ begin
+ if Present (T) and then Present (Predicate_Function (T)) then
+ Set_Has_Predicates (Typ);
+
+ -- Build the call to the predicate function of T
+
+ Exp :=
+ Make_Predicate_Call
+ (T, Convert_To (T, Make_Identifier (Loc, Object_Name)));
+
+ -- Add call to evolving expression, using AND THEN if needed
+
+ if No (Expr) then
+ Expr := Exp;
+ else
+ Expr :=
+ Make_And_Then (Loc,
+ Left_Opnd => Relocate_Node (Expr),
+ Right_Opnd => Exp);
+ end if;
+
+ -- Output info message on inheritance if required. Note we do not
+ -- give this information for generic actual types, since it is
+ -- unwelcome noise in that case in instantiations. We also
+ -- generally suppress the message in instantiations, and also
+ -- if it involves internal names.
+
+ if Opt.List_Inherited_Aspects
+ and then not Is_Generic_Actual_Type (Typ)
+ and then Instantiation_Depth (Sloc (Typ)) = 0
+ and then not Is_Internal_Name (Chars (T))
+ and then not Is_Internal_Name (Chars (Typ))
+ then
+ Error_Msg_Sloc := Sloc (Predicate_Function (T));
+ Error_Msg_Node_2 := T;
+ Error_Msg_N ("?info: & inherits predicate from & #", Typ);
+ end if;
+ end if;
+ end Add_Call;
+
+ --------------------
+ -- Add_Predicates --
+ --------------------
+
+ procedure Add_Predicates is
+ Ritem : Node_Id;
+ Arg1 : Node_Id;
+ Arg2 : Node_Id;
+
+ procedure Replace_Type_Reference (N : Node_Id);
+ -- Replace a single occurrence N of the subtype name with a reference
+ -- to the formal of the predicate function. N can be an identifier
+ -- referencing the subtype, or a selected component, representing an
+ -- appropriately qualified occurrence of the subtype name.
+
+ procedure Replace_Type_References is
+ new Replace_Type_References_Generic (Replace_Type_Reference);
+ -- Traverse an expression changing every occurrence of an identifier
+ -- whose name matches the name of the subtype with a reference to
+ -- the formal parameter of the predicate function.
+
+ ----------------------------
+ -- Replace_Type_Reference --
+ ----------------------------
+
+ procedure Replace_Type_Reference (N : Node_Id) is
+ begin
+ Rewrite (N, Make_Identifier (Loc, Object_Name));
+ end Replace_Type_Reference;
+
+ -- Start of processing for Add_Predicates
+
+ begin
+ Ritem := First_Rep_Item (Typ);
+ while Present (Ritem) loop
+ if Nkind (Ritem) = N_Pragma
+ and then Pragma_Name (Ritem) = Name_Predicate
+ then
+ Arg1 := First (Pragma_Argument_Associations (Ritem));
+ Arg2 := Next (Arg1);
+
+ Arg1 := Get_Pragma_Arg (Arg1);
+ Arg2 := Get_Pragma_Arg (Arg2);
+
+ -- See if this predicate pragma is for the current type
+
+ if Entity (Arg1) = Typ then
+
+ -- We have a match, this entry is for our subtype
+
+ -- First We need to replace any occurrences of the name of
+ -- the type with references to the object.
+
+ Replace_Type_References (Arg2, Chars (Typ));
+
+ -- OK, replacement complete, now we can add the expression
+
+ if No (Expr) then
+ Expr := Relocate_Node (Arg2);
+
+ -- There already was a predicate, so add to it
+
+ else
+ Expr :=
+ Make_And_Then (Loc,
+ Left_Opnd => Relocate_Node (Expr),
+ Right_Opnd => Relocate_Node (Arg2));
+ end if;
+ end if;
+ end if;
+
+ Next_Rep_Item (Ritem);
+ end loop;
+ end Add_Predicates;
+
+ -- Start of processing for Build_Predicate_Function
+
+ begin
+ -- Initialize for construction of statement list
+
+ Expr := Empty;
+
+ -- Return if already built or if type does not have predicates
+
+ if not Has_Predicates (Typ)
+ or else Present (Predicate_Function (Typ))
+ then
+ return;
+ end if;
+
+ -- Add Predicates for the current type
+
+ Add_Predicates;
+
+ -- Add predicates for ancestor if present
+
+ declare
+ Atyp : constant Entity_Id := Nearest_Ancestor (Typ);
+ begin
+ if Present (Atyp) then
+ Add_Call (Atyp);
+ end if;
+ end;
+
+ -- If we have predicates, build the function
+
+ if Present (Expr) then
+
+ -- Build function declaration
+
+ pragma Assert (Has_Predicates (Typ));
+ SId :=
+ Make_Defining_Identifier (Loc,
+ Chars => New_External_Name (Chars (Typ), "Predicate"));
+ Set_Has_Predicates (SId);
+ Set_Predicate_Function (Typ, SId);
+
+ Spec :=
+ Make_Function_Specification (Loc,
+ Defining_Unit_Name => SId,
+ Parameter_Specifications => New_List (
+ Make_Parameter_Specification (Loc,
+ Defining_Identifier =>
+ Make_Defining_Identifier (Loc, Object_Name),
+ Parameter_Type => New_Occurrence_Of (Typ, Loc))),
+ Result_Definition =>
+ New_Occurrence_Of (Standard_Boolean, Loc));
+
+ FDecl := Make_Subprogram_Declaration (Loc, Specification => Spec);
+
+ -- Build function body
+
+ SId :=
+ Make_Defining_Identifier (Loc,
+ Chars => New_External_Name (Chars (Typ), "Predicate"));
+
+ Spec :=
+ Make_Function_Specification (Loc,
+ Defining_Unit_Name => SId,
+ Parameter_Specifications => New_List (
+ Make_Parameter_Specification (Loc,
+ Defining_Identifier =>
+ Make_Defining_Identifier (Loc, Object_Name),
+ Parameter_Type =>
+ New_Occurrence_Of (Typ, Loc))),
+ Result_Definition =>
+ New_Occurrence_Of (Standard_Boolean, Loc));
+
+ FBody :=
+ Make_Subprogram_Body (Loc,
+ Specification => Spec,
+ Declarations => Empty_List,
+ Handled_Statement_Sequence =>
+ Make_Handled_Sequence_Of_Statements (Loc,
+ Statements => New_List (
+ Make_Simple_Return_Statement (Loc,
+ Expression => Expr))));
+
+ -- Insert declaration before freeze node and body after
+
+ Insert_Before_And_Analyze (N, FDecl);
+ Insert_After_And_Analyze (N, FBody);
+
+ -- Deal with static predicate case
+
+ if Ekind_In (Typ, E_Enumeration_Subtype,
+ E_Modular_Integer_Subtype,
+ E_Signed_Integer_Subtype)
+ and then Is_Static_Subtype (Typ)
+ then
+ Build_Static_Predicate (Typ, Expr, Object_Name);
+ end if;
+ end if;
+ end Build_Predicate_Function;
+
+ ----------------------------
+ -- Build_Static_Predicate --
+ ----------------------------
+
+ procedure Build_Static_Predicate
+ (Typ : Entity_Id;
+ Expr : Node_Id;
+ Nam : Name_Id)
+ is
+ Loc : constant Source_Ptr := Sloc (Expr);
+
+ Non_Static : exception;
+ -- Raised if something non-static is found
+
+ Btyp : constant Entity_Id := Base_Type (Typ);
+
+ BLo : constant Uint := Expr_Value (Type_Low_Bound (Btyp));
+ BHi : constant Uint := Expr_Value (Type_High_Bound (Btyp));
+ -- Low bound and high bound value of base type of Typ
+
+ TLo : constant Uint := Expr_Value (Type_Low_Bound (Typ));
+ THi : constant Uint := Expr_Value (Type_High_Bound (Typ));
+ -- Low bound and high bound values of static subtype Typ
+
+ type REnt is record
+ Lo, Hi : Uint;
+ end record;
+ -- One entry in a Rlist value, a single REnt (range entry) value
+ -- denotes one range from Lo to Hi. To represent a single value
+ -- range Lo = Hi = value.
+
+ type RList is array (Nat range <>) of REnt;
+ -- A list of ranges. The ranges are sorted in increasing order,
+ -- and are disjoint (there is a gap of at least one value between
+ -- each range in the table). A value is in the set of ranges in
+ -- Rlist if it lies within one of these ranges
+
+ False_Range : constant RList :=
+ RList'(1 .. 0 => REnt'(No_Uint, No_Uint));
+ -- An empty set of ranges represents a range list that can never be
+ -- satisfied, since there are no ranges in which the value could lie,
+ -- so it does not lie in any of them. False_Range is a canonical value
+ -- for this empty set, but general processing should test for an Rlist
+ -- with length zero (see Is_False predicate), since other null ranges
+ -- may appear which must be treated as False.
+
+ True_Range : constant RList := RList'(1 => REnt'(BLo, BHi));
+ -- Range representing True, value must be in the base range
+
+ function "and" (Left, Right : RList) return RList;
+ -- And's together two range lists, returning a range list. This is
+ -- a set intersection operation.
+
+ function "or" (Left, Right : RList) return RList;
+ -- Or's together two range lists, returning a range list. This is a
+ -- set union operation.
+
+ function "not" (Right : RList) return RList;
+ -- Returns complement of a given range list, i.e. a range list
+ -- representing all the values in TLo .. THi that are not in the
+ -- input operand Right.
+
+ function Build_Val (V : Uint) return Node_Id;
+ -- Return an analyzed N_Identifier node referencing this value, suitable
+ -- for use as an entry in the Static_Predicate list. This node is typed
+ -- with the base type.
+
+ function Build_Range (Lo, Hi : Uint) return Node_Id;
+ -- Return an analyzed N_Range node referencing this range, suitable
+ -- for use as an entry in the Static_Predicate list. This node is typed
+ -- with the base type.
+
+ function Get_RList (Exp : Node_Id) return RList;
+ -- This is a recursive routine that converts the given expression into
+ -- a list of ranges, suitable for use in building the static predicate.
+
+ function Is_False (R : RList) return Boolean;
+ pragma Inline (Is_False);
+ -- Returns True if the given range list is empty, and thus represents
+ -- a False list of ranges that can never be satisfied.
+
+ function Is_True (R : RList) return Boolean;
+ -- Returns True if R trivially represents the True predicate by having
+ -- a single range from BLo to BHi.
+
+ function Is_Type_Ref (N : Node_Id) return Boolean;
+ pragma Inline (Is_Type_Ref);
+ -- Returns if True if N is a reference to the type for the predicate in
+ -- the expression (i.e. if it is an identifier whose Chars field matches
+ -- the Nam given in the call).
+
+ function Lo_Val (N : Node_Id) return Uint;
+ -- Given static expression or static range from a Static_Predicate list,
+ -- gets expression value or low bound of range.
+
+ function Hi_Val (N : Node_Id) return Uint;
+ -- Given static expression or static range from a Static_Predicate list,
+ -- gets expression value of high bound of range.
+
+ function Membership_Entry (N : Node_Id) return RList;
+ -- Given a single membership entry (range, value, or subtype), returns
+ -- the corresponding range list. Raises Static_Error if not static.
+
+ function Membership_Entries (N : Node_Id) return RList;
+ -- Given an element on an alternatives list of a membership operation,
+ -- returns the range list corresponding to this entry and all following
+ -- entries (i.e. returns the "or" of this list of values).
+
+ function Stat_Pred (Typ : Entity_Id) return RList;
+ -- Given a type, if it has a static predicate, then return the predicate
+ -- as a range list, otherwise raise Non_Static.
+
+ -----------
+ -- "and" --
+ -----------
+
+ function "and" (Left, Right : RList) return RList is
+ FEnt : REnt;
+ -- First range of result
+
+ SLeft : Nat := Left'First;
+ -- Start of rest of left entries
+
+ SRight : Nat := Right'First;
+ -- Start of rest of right entries
+
+ begin
+ -- If either range is True, return the other
+
+ if Is_True (Left) then
+ return Right;
+ elsif Is_True (Right) then
+ return Left;
+ end if;
+
+ -- If either range is False, return False
+
+ if Is_False (Left) or else Is_False (Right) then
+ return False_Range;
+ end if;
+
+ -- Loop to remove entries at start that are disjoint, and thus
+ -- just get discarded from the result entirely.
+
+ loop
+ -- If no operands left in either operand, result is false
+
+ if SLeft > Left'Last or else SRight > Right'Last then
+ return False_Range;
+
+ -- Discard first left operand entry if disjoint with right
+
+ elsif Left (SLeft).Hi < Right (SRight).Lo then
+ SLeft := SLeft + 1;
+
+ -- Discard first right operand entry if disjoint with left
+
+ elsif Right (SRight).Hi < Left (SLeft).Lo then
+ SRight := SRight + 1;
+
+ -- Otherwise we have an overlapping entry
+
+ else
+ exit;
+ end if;
+ end loop;
+
+ -- Now we have two non-null operands, and first entries overlap.
+ -- The first entry in the result will be the overlapping part of
+ -- these two entries.
+
+ FEnt := REnt'(Lo => UI_Max (Left (SLeft).Lo, Right (SRight).Lo),
+ Hi => UI_Min (Left (SLeft).Hi, Right (SRight).Hi));
+
+ -- Now we can remove the entry that ended at a lower value, since
+ -- its contribution is entirely contained in Fent.
+
+ if Left (SLeft).Hi <= Right (SRight).Hi then
+ SLeft := SLeft + 1;
+ else
+ SRight := SRight + 1;
+ end if;
+
+ -- Compute result by concatenating this first entry with the "and"
+ -- of the remaining parts of the left and right operands. Note that
+ -- if either of these is empty, "and" will yield empty, so that we
+ -- will end up with just Fent, which is what we want in that case.
+
+ return
+ FEnt & (Left (SLeft .. Left'Last) and Right (SRight .. Right'Last));
+ end "and";
+
+ -----------
+ -- "not" --
+ -----------
+
+ function "not" (Right : RList) return RList is
+ begin
+ -- Return True if False range
+
+ if Is_False (Right) then
+ return True_Range;
+ end if;
+
+ -- Return False if True range
+
+ if Is_True (Right) then
+ return False_Range;
+ end if;
+
+ -- Here if not trivial case
+
+ declare
+ Result : RList (1 .. Right'Length + 1);
+ -- May need one more entry for gap at beginning and end
+
+ Count : Nat := 0;
+ -- Number of entries stored in Result
+
+ begin
+ -- Gap at start
+
+ if Right (Right'First).Lo > TLo then
+ Count := Count + 1;
+ Result (Count) := REnt'(TLo, Right (Right'First).Lo - 1);
+ end if;
+
+ -- Gaps between ranges
+
+ for J in Right'First .. Right'Last - 1 loop
+ Count := Count + 1;
+ Result (Count) :=
+ REnt'(Right (J).Hi + 1, Right (J + 1).Lo - 1);
+ end loop;
+
+ -- Gap at end
+
+ if Right (Right'Last).Hi < THi then
+ Count := Count + 1;
+ Result (Count) := REnt'(Right (Right'Last).Hi + 1, THi);
+ end if;
+
+ return Result (1 .. Count);
+ end;
+ end "not";
+
+ ----------
+ -- "or" --
+ ----------
+
+ function "or" (Left, Right : RList) return RList is
+ FEnt : REnt;
+ -- First range of result
+
+ SLeft : Nat := Left'First;
+ -- Start of rest of left entries
+
+ SRight : Nat := Right'First;
+ -- Start of rest of right entries
+
+ begin
+ -- If either range is True, return True
+
+ if Is_True (Left) or else Is_True (Right) then
+ return True_Range;
+ end if;
+
+ -- If either range is False (empty), return the other
+
+ if Is_False (Left) then
+ return Right;
+ elsif Is_False (Right) then
+ return Left;
+ end if;
+
+ -- Initialize result first entry from left or right operand
+ -- depending on which starts with the lower range.
+
+ if Left (SLeft).Lo < Right (SRight).Lo then
+ FEnt := Left (SLeft);
+ SLeft := SLeft + 1;
+ else
+ FEnt := Right (SRight);
+ SRight := SRight + 1;
+ end if;
+
+ -- This loop eats ranges from left and right operands that
+ -- are contiguous with the first range we are gathering.
+
+ loop
+ -- Eat first entry in left operand if contiguous or
+ -- overlapped by gathered first operand of result.
+
+ if SLeft <= Left'Last
+ and then Left (SLeft).Lo <= FEnt.Hi + 1
+ then
+ FEnt.Hi := UI_Max (FEnt.Hi, Left (SLeft).Hi);
+ SLeft := SLeft + 1;
+
+ -- Eat first entry in right operand if contiguous or
+ -- overlapped by gathered right operand of result.
+
+ elsif SRight <= Right'Last
+ and then Right (SRight).Lo <= FEnt.Hi + 1
+ then
+ FEnt.Hi := UI_Max (FEnt.Hi, Right (SRight).Hi);
+ SRight := SRight + 1;
+
+ -- All done if no more entries to eat!
+
+ else
+ exit;
+ end if;
+ end loop;
+
+ -- Obtain result as the first entry we just computed, concatenated
+ -- to the "or" of the remaining results (if one operand is empty,
+ -- this will just concatenate with the other
+
+ return
+ FEnt & (Left (SLeft .. Left'Last) or Right (SRight .. Right'Last));
+ end "or";
+
+ -----------------
+ -- Build_Range --
+ -----------------
+
+ function Build_Range (Lo, Hi : Uint) return Node_Id is
+ Result : Node_Id;
+ begin
+ if Lo = Hi then
+ return Build_Val (Hi);
+ else
+ Result :=
+ Make_Range (Loc,
+ Low_Bound => Build_Val (Lo),
+ High_Bound => Build_Val (Hi));
+ Set_Etype (Result, Btyp);
+ Set_Analyzed (Result);
+ return Result;
+ end if;
+ end Build_Range;
+
+ ---------------
+ -- Build_Val --
+ ---------------
+
+ function Build_Val (V : Uint) return Node_Id is
+ Result : Node_Id;
+
+ begin
+ if Is_Enumeration_Type (Typ) then
+ Result := Get_Enum_Lit_From_Pos (Typ, V, Loc);
+ else
+ Result := Make_Integer_Literal (Loc, V);
+ end if;
+
+ Set_Etype (Result, Btyp);
+ Set_Is_Static_Expression (Result);
+ Set_Analyzed (Result);
+ return Result;
+ end Build_Val;
+
+ ---------------
+ -- Get_RList --
+ ---------------
+
+ function Get_RList (Exp : Node_Id) return RList is
+ Op : Node_Kind;
+ Val : Uint;
+
+ begin
+ -- Static expression can only be true or false
+
+ if Is_OK_Static_Expression (Exp) then
+
+ -- For False
+
+ if Expr_Value (Exp) = 0 then
+ return False_Range;
+ else
+ return True_Range;
+ end if;
+ end if;
+
+ -- Otherwise test node type
+
+ Op := Nkind (Exp);
+
+ case Op is
+
+ -- And
+
+ when N_Op_And | N_And_Then =>
+ return Get_RList (Left_Opnd (Exp))
+ and
+ Get_RList (Right_Opnd (Exp));
+
+ -- Or
+
+ when N_Op_Or | N_Or_Else =>
+ return Get_RList (Left_Opnd (Exp))
+ or
+ Get_RList (Right_Opnd (Exp));
+
+ -- Not
+
+ when N_Op_Not =>
+ return not Get_RList (Right_Opnd (Exp));
+
+ -- Comparisons of type with static value
+
+ when N_Op_Compare =>
+ -- Type is left operand
+
+ if Is_Type_Ref (Left_Opnd (Exp))
+ and then Is_OK_Static_Expression (Right_Opnd (Exp))
+ then
+ Val := Expr_Value (Right_Opnd (Exp));
+
+ -- Typ is right operand
+
+ elsif Is_Type_Ref (Right_Opnd (Exp))
+ and then Is_OK_Static_Expression (Left_Opnd (Exp))
+ then
+ Val := Expr_Value (Left_Opnd (Exp));
+
+ -- Invert sense of comparison
+
+ case Op is
+ when N_Op_Gt => Op := N_Op_Lt;
+ when N_Op_Lt => Op := N_Op_Gt;
+ when N_Op_Ge => Op := N_Op_Le;
+ when N_Op_Le => Op := N_Op_Ge;
+ when others => null;
+ end case;
+
+ -- Other cases are non-static
+
+ else
+ raise Non_Static;
+ end if;
+
+ -- Construct range according to comparison operation
+
+ case Op is
+ when N_Op_Eq =>
+ return RList'(1 => REnt'(Val, Val));
+
+ when N_Op_Ge =>
+ return RList'(1 => REnt'(Val, BHi));
+
+ when N_Op_Gt =>
+ return RList'(1 => REnt'(Val + 1, BHi));
+
+ when N_Op_Le =>
+ return RList'(1 => REnt'(BLo, Val));
+
+ when N_Op_Lt =>
+ return RList'(1 => REnt'(BLo, Val - 1));
+
+ when N_Op_Ne =>
+ return RList'(REnt'(BLo, Val - 1),
+ REnt'(Val + 1, BHi));
+
+ when others =>
+ raise Program_Error;
+ end case;
+
+ -- Membership (IN)
+
+ when N_In =>
+ if not Is_Type_Ref (Left_Opnd (Exp)) then
+ raise Non_Static;
+ end if;
+
+ if Present (Right_Opnd (Exp)) then
+ return Membership_Entry (Right_Opnd (Exp));
+ else
+ return Membership_Entries (First (Alternatives (Exp)));
+ end if;
+
+ -- Negative membership (NOT IN)
+
+ when N_Not_In =>
+ if not Is_Type_Ref (Left_Opnd (Exp)) then
+ raise Non_Static;
+ end if;
+
+ if Present (Right_Opnd (Exp)) then
+ return not Membership_Entry (Right_Opnd (Exp));
+ else
+ return not Membership_Entries (First (Alternatives (Exp)));
+ end if;
+
+ -- Function call, may be call to static predicate
+
+ when N_Function_Call =>
+ if Is_Entity_Name (Name (Exp)) then
+ declare
+ Ent : constant Entity_Id := Entity (Name (Exp));
+ begin
+ if Has_Predicates (Ent) then
+ return Stat_Pred (Etype (First_Formal (Ent)));
+ end if;
+ end;
+ end if;
+
+ -- Other function call cases are non-static
+
+ raise Non_Static;
+
+ -- Qualified expression, dig out the expression
+
+ when N_Qualified_Expression =>
+ return Get_RList (Expression (Exp));
+
+ -- Xor operator
+
+ when N_Op_Xor =>
+ return (Get_RList (Left_Opnd (Exp))
+ and not Get_RList (Right_Opnd (Exp)))
+ or (Get_RList (Right_Opnd (Exp))
+ and not Get_RList (Left_Opnd (Exp)));
+
+ -- Any other node type is non-static
+
+ when others =>
+ raise Non_Static;
+ end case;
+ end Get_RList;
+
+ ------------
+ -- Hi_Val --
+ ------------
+
+ function Hi_Val (N : Node_Id) return Uint is
+ begin
+ if Is_Static_Expression (N) then
+ return Expr_Value (N);
+ else
+ pragma Assert (Nkind (N) = N_Range);
+ return Expr_Value (High_Bound (N));
+ end if;
+ end Hi_Val;
+
+ --------------
+ -- Is_False --
+ --------------
+
+ function Is_False (R : RList) return Boolean is
+ begin
+ return R'Length = 0;
+ end Is_False;
+
+ -------------
+ -- Is_True --
+ -------------
+
+ function Is_True (R : RList) return Boolean is
+ begin
+ return R'Length = 1
+ and then R (R'First).Lo = BLo
+ and then R (R'First).Hi = BHi;
+ end Is_True;
+
+ -----------------
+ -- Is_Type_Ref --
+ -----------------
+
+ function Is_Type_Ref (N : Node_Id) return Boolean is
+ begin
+ return Nkind (N) = N_Identifier and then Chars (N) = Nam;
+ end Is_Type_Ref;
+
+ ------------
+ -- Lo_Val --
+ ------------
+
+ function Lo_Val (N : Node_Id) return Uint is
+ begin
+ if Is_Static_Expression (N) then
+ return Expr_Value (N);
+ else
+ pragma Assert (Nkind (N) = N_Range);
+ return Expr_Value (Low_Bound (N));
+ end if;
+ end Lo_Val;
+
+ ------------------------
+ -- Membership_Entries --
+ ------------------------
+
+ function Membership_Entries (N : Node_Id) return RList is
+ begin
+ if No (Next (N)) then
+ return Membership_Entry (N);
+ else
+ return Membership_Entry (N) or Membership_Entries (Next (N));
+ end if;
+ end Membership_Entries;
+
+ ----------------------
+ -- Membership_Entry --
+ ----------------------
+
+ function Membership_Entry (N : Node_Id) return RList is
+ Val : Uint;
+ SLo : Uint;
+ SHi : Uint;
+
+ begin
+ -- Range case
+
+ if Nkind (N) = N_Range then
+ if not Is_Static_Expression (Low_Bound (N))
+ or else
+ not Is_Static_Expression (High_Bound (N))
+ then
+ raise Non_Static;
+ else
+ SLo := Expr_Value (Low_Bound (N));
+ SHi := Expr_Value (High_Bound (N));
+ return RList'(1 => REnt'(SLo, SHi));
+ end if;
+
+ -- Static expression case
+
+ elsif Is_Static_Expression (N) then
+ Val := Expr_Value (N);
+ return RList'(1 => REnt'(Val, Val));
+
+ -- Identifier (other than static expression) case
+
+ else pragma Assert (Nkind (N) = N_Identifier);
+
+ -- Type case
+
+ if Is_Type (Entity (N)) then
+
+ -- If type has predicates, process them
+
+ if Has_Predicates (Entity (N)) then
+ return Stat_Pred (Entity (N));
+
+ -- For static subtype without predicates, get range
+
+ elsif Is_Static_Subtype (Entity (N)) then
+ SLo := Expr_Value (Type_Low_Bound (Entity (N)));
+ SHi := Expr_Value (Type_High_Bound (Entity (N)));
+ return RList'(1 => REnt'(SLo, SHi));
+
+ -- Any other type makes us non-static
+
+ else
+ raise Non_Static;
+ end if;
+
+ -- Any other kind of identifier in predicate (e.g. a non-static
+ -- expression value) means this is not a static predicate.
+
+ else
+ raise Non_Static;
+ end if;
+ end if;
+ end Membership_Entry;
+
+ ---------------
+ -- Stat_Pred --
+ ---------------
+
+ function Stat_Pred (Typ : Entity_Id) return RList is
+ begin
+ -- Not static if type does not have static predicates
+
+ if not Has_Predicates (Typ)
+ or else No (Static_Predicate (Typ))
+ then
+ raise Non_Static;
+ end if;
+
+ -- Otherwise we convert the predicate list to a range list
+
+ declare
+ Result : RList (1 .. List_Length (Static_Predicate (Typ)));
+ P : Node_Id;
+
+ begin
+ P := First (Static_Predicate (Typ));
+ for J in Result'Range loop
+ Result (J) := REnt'(Lo_Val (P), Hi_Val (P));
+ Next (P);
+ end loop;
+
+ return Result;
+ end;
+ end Stat_Pred;
+
+ -- Start of processing for Build_Static_Predicate
+
+ begin
+ -- Now analyze the expression to see if it is a static predicate
+
+ declare
+ Ranges : constant RList := Get_RList (Expr);
+ -- Range list from expression if it is static
+
+ Plist : List_Id;
+
+ begin
+ -- Convert range list into a form for the static predicate. In the
+ -- Ranges array, we just have raw ranges, these must be converted
+ -- to properly typed and analyzed static expressions or range nodes.
+
+ -- Note: here we limit ranges to the ranges of the subtype, so that
+ -- a predicate is always false for values outside the subtype. That
+ -- seems fine, such values are invalid anyway, and considering them
+ -- to fail the predicate seems allowed and friendly, and furthermore
+ -- simplifies processing for case statements and loops.
+
+ Plist := New_List;
+
+ for J in Ranges'Range loop
+ declare
+ Lo : Uint := Ranges (J).Lo;
+ Hi : Uint := Ranges (J).Hi;
+
+ begin
+ -- Ignore completely out of range entry
+
+ if Hi < TLo or else Lo > THi then
+ null;
+
+ -- Otherwise process entry
+
+ else
+ -- Adjust out of range value to subtype range
+
+ if Lo < TLo then
+ Lo := TLo;
+ end if;
+
+ if Hi > THi then
+ Hi := THi;
+ end if;
+
+ -- Convert range into required form
+
+ if Lo = Hi then
+ Append_To (Plist, Build_Val (Lo));
+ else
+ Append_To (Plist, Build_Range (Lo, Hi));
+ end if;
+ end if;
+ end;
+ end loop;
+
+ -- Processing was successful and all entries were static, so now we
+ -- can store the result as the predicate list.
+
+ Set_Static_Predicate (Typ, Plist);
+
+ -- The processing for static predicates put the expression into
+ -- canonical form as a series of ranges. It also eliminated
+ -- duplicates and collapsed and combined ranges. We might as well
+ -- replace the alternatives list of the right operand of the
+ -- membership test with the static predicate list, which will
+ -- usually be more efficient.
+
+ declare
+ New_Alts : constant List_Id := New_List;
+ Old_Node : Node_Id;
+ New_Node : Node_Id;
+
+ begin
+ Old_Node := First (Plist);
+ while Present (Old_Node) loop
+ New_Node := New_Copy (Old_Node);
+
+ if Nkind (New_Node) = N_Range then
+ Set_Low_Bound (New_Node, New_Copy (Low_Bound (Old_Node)));
+ Set_High_Bound (New_Node, New_Copy (High_Bound (Old_Node)));
+ end if;
+
+ Append_To (New_Alts, New_Node);
+ Next (Old_Node);
+ end loop;
+
+ -- If empty list, replace by False
+
+ if Is_Empty_List (New_Alts) then
+ Rewrite (Expr, New_Occurrence_Of (Standard_False, Loc));
+
+ -- Else replace by set membership test
+
+ else
+ Rewrite (Expr,
+ Make_In (Loc,
+ Left_Opnd => Make_Identifier (Loc, Nam),
+ Right_Opnd => Empty,
+ Alternatives => New_Alts));
+
+ -- Resolve new expression in function context
+
+ Install_Formals (Predicate_Function (Typ));
+ Push_Scope (Predicate_Function (Typ));
+ Analyze_And_Resolve (Expr, Standard_Boolean);
+ Pop_Scope;
+ end if;
+ end;
+ end;
+
+ -- If non-static, return doing nothing
+
+ exception
+ when Non_Static =>
+ return;
+ end Build_Static_Predicate;
+
+ -----------------------------------
+ -- Check_Constant_Address_Clause --
+ -----------------------------------
+
+ procedure Check_Constant_Address_Clause
+ (Expr : Node_Id;
+ U_Ent : Entity_Id)
+ is
+ procedure Check_At_Constant_Address (Nod : Node_Id);
+ -- Checks that the given node N represents a name whose 'Address is
+ -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
+ -- address value is the same at the point of declaration of U_Ent and at
+ -- the time of elaboration of the address clause.
+
+ procedure Check_Expr_Constants (Nod : Node_Id);
+ -- Checks that Nod meets the requirements for a constant address clause
+ -- in the sense of the enclosing procedure.
+
+ procedure Check_List_Constants (Lst : List_Id);
+ -- Check that all elements of list Lst meet the requirements for a
+ -- constant address clause in the sense of the enclosing procedure.
+
+ -------------------------------
+ -- Check_At_Constant_Address --
+ -------------------------------
+
+ procedure Check_At_Constant_Address (Nod : Node_Id) is
+ begin
+ if Is_Entity_Name (Nod) then
+ if Present (Address_Clause (Entity ((Nod)))) then
+ Error_Msg_NE
+ ("invalid address clause for initialized object &!",
+ Nod, U_Ent);
+ Error_Msg_NE
+ ("address for& cannot" &
+ " depend on another address clause! (RM 13.1(22))!",
+ Nod, U_Ent);
+
+ elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
+ and then Sloc (U_Ent) < Sloc (Entity (Nod))
+ then
+ Error_Msg_NE
+ ("invalid address clause for initialized object &!",
+ Nod, U_Ent);
+ Error_Msg_Node_2 := U_Ent;
+ Error_Msg_NE
+ ("\& must be defined before & (RM 13.1(22))!",
+ Nod, Entity (Nod));
+ end if;
+
+ elsif Nkind (Nod) = N_Selected_Component then
+ declare
+ T : constant Entity_Id := Etype (Prefix (Nod));
+
+ begin
+ if (Is_Record_Type (T)
+ and then Has_Discriminants (T))
+ or else
+ (Is_Access_Type (T)
+ and then Is_Record_Type (Designated_Type (T))
+ and then Has_Discriminants (Designated_Type (T)))
+ then
+ Error_Msg_NE
+ ("invalid address clause for initialized object &!",
+ Nod, U_Ent);
+ Error_Msg_N
+ ("\address cannot depend on component" &
+ " of discriminated record (RM 13.1(22))!",
+ Nod);
+ else
+ Check_At_Constant_Address (Prefix (Nod));
+ end if;
+ end;
+
+ elsif Nkind (Nod) = N_Indexed_Component then
+ Check_At_Constant_Address (Prefix (Nod));
+ Check_List_Constants (Expressions (Nod));
+
+ else
+ Check_Expr_Constants (Nod);
+ end if;
+ end Check_At_Constant_Address;
+
+ --------------------------
+ -- Check_Expr_Constants --
+ --------------------------
+
+ procedure Check_Expr_Constants (Nod : Node_Id) is
+ Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
+ Ent : Entity_Id := Empty;
+
+ begin
+ if Nkind (Nod) in N_Has_Etype
+ and then Etype (Nod) = Any_Type
+ then
+ return;
+ end if;
+
+ case Nkind (Nod) is
+ when N_Empty | N_Error =>
+ return;
+
+ when N_Identifier | N_Expanded_Name =>
+ Ent := Entity (Nod);
+
+ -- We need to look at the original node if it is different
+ -- from the node, since we may have rewritten things and
+ -- substituted an identifier representing the rewrite.
+
+ if Original_Node (Nod) /= Nod then
+ Check_Expr_Constants (Original_Node (Nod));
+
+ -- If the node is an object declaration without initial
+ -- value, some code has been expanded, and the expression
+ -- is not constant, even if the constituents might be
+ -- acceptable, as in A'Address + offset.
+
+ if Ekind (Ent) = E_Variable
+ and then
+ Nkind (Declaration_Node (Ent)) = N_Object_Declaration
+ and then
+ No (Expression (Declaration_Node (Ent)))
+ then
+ Error_Msg_NE
+ ("invalid address clause for initialized object &!",
+ Nod, U_Ent);
+
+ -- If entity is constant, it may be the result of expanding
+ -- a check. We must verify that its declaration appears
+ -- before the object in question, else we also reject the
+ -- address clause.
+
+ elsif Ekind (Ent) = E_Constant
+ and then In_Same_Source_Unit (Ent, U_Ent)
+ and then Sloc (Ent) > Loc_U_Ent
+ then
+ Error_Msg_NE
+ ("invalid address clause for initialized object &!",
+ Nod, U_Ent);
+ end if;
+
+ return;
+ end if;
+
+ -- Otherwise look at the identifier and see if it is OK
+
+ if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
+ or else Is_Type (Ent)
+ then
+ return;
+
+ elsif
+ Ekind (Ent) = E_Constant
+ or else
+ Ekind (Ent) = E_In_Parameter
+ then
+ -- This is the case where we must have Ent defined before
+ -- U_Ent. Clearly if they are in different units this
+ -- requirement is met since the unit containing Ent is
+ -- already processed.
+
+ if not In_Same_Source_Unit (Ent, U_Ent) then
+ return;
+
+ -- Otherwise location of Ent must be before the location
+ -- of U_Ent, that's what prior defined means.
+
+ elsif Sloc (Ent) < Loc_U_Ent then
+ return;
+
+ else
+ Error_Msg_NE
+ ("invalid address clause for initialized object &!",
+ Nod, U_Ent);
+ Error_Msg_Node_2 := U_Ent;
+ Error_Msg_NE
+ ("\& must be defined before & (RM 13.1(22))!",
+ Nod, Ent);
+ end if;
+
+ elsif Nkind (Original_Node (Nod)) = N_Function_Call then
+ Check_Expr_Constants (Original_Node (Nod));
+
+ else
+ Error_Msg_NE
+ ("invalid address clause for initialized object &!",
+ Nod, U_Ent);
+
+ if Comes_From_Source (Ent) then
+ Error_Msg_NE
+ ("\reference to variable& not allowed"
+ & " (RM 13.1(22))!", Nod, Ent);
+ else
+ Error_Msg_N
+ ("non-static expression not allowed"
+ & " (RM 13.1(22))!", Nod);
+ end if;
+ end if;
+
+ when N_Integer_Literal =>
+
+ -- If this is a rewritten unchecked conversion, in a system
+ -- where Address is an integer type, always use the base type
+ -- for a literal value. This is user-friendly and prevents
+ -- order-of-elaboration issues with instances of unchecked
+ -- conversion.
+
+ if Nkind (Original_Node (Nod)) = N_Function_Call then
+ Set_Etype (Nod, Base_Type (Etype (Nod)));
+ end if;
+
+ when N_Real_Literal |
+ N_String_Literal |
+ N_Character_Literal =>
+ return;
+
+ when N_Range =>
+ Check_Expr_Constants (Low_Bound (Nod));
+ Check_Expr_Constants (High_Bound (Nod));
+
+ when N_Explicit_Dereference =>
+ Check_Expr_Constants (Prefix (Nod));
+
+ when N_Indexed_Component =>
+ Check_Expr_Constants (Prefix (Nod));
+ Check_List_Constants (Expressions (Nod));
+
+ when N_Slice =>
+ Check_Expr_Constants (Prefix (Nod));
+ Check_Expr_Constants (Discrete_Range (Nod));
+
+ when N_Selected_Component =>
+ Check_Expr_Constants (Prefix (Nod));
+
+ when N_Attribute_Reference =>
+ if Attribute_Name (Nod) = Name_Address
+ or else
+ Attribute_Name (Nod) = Name_Access
+ or else
+ Attribute_Name (Nod) = Name_Unchecked_Access
+ or else
+ Attribute_Name (Nod) = Name_Unrestricted_Access
+ then
+ Check_At_Constant_Address (Prefix (Nod));
+
+ else
+ Check_Expr_Constants (Prefix (Nod));
+ Check_List_Constants (Expressions (Nod));
+ end if;
+
+ when N_Aggregate =>
+ Check_List_Constants (Component_Associations (Nod));
+ Check_List_Constants (Expressions (Nod));
+
+ when N_Component_Association =>
+ Check_Expr_Constants (Expression (Nod));
+
+ when N_Extension_Aggregate =>
+ Check_Expr_Constants (Ancestor_Part (Nod));
+ Check_List_Constants (Component_Associations (Nod));
+ Check_List_Constants (Expressions (Nod));
+
+ when N_Null =>
+ return;
+
+ when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
+ Check_Expr_Constants (Left_Opnd (Nod));
+ Check_Expr_Constants (Right_Opnd (Nod));
+
+ when N_Unary_Op =>
+ Check_Expr_Constants (Right_Opnd (Nod));
+
+ when N_Type_Conversion |
+ N_Qualified_Expression |
+ N_Allocator =>
+ Check_Expr_Constants (Expression (Nod));
+
+ when N_Unchecked_Type_Conversion =>
+ Check_Expr_Constants (Expression (Nod));
+
+ -- If this is a rewritten unchecked conversion, subtypes in
+ -- this node are those created within the instance. To avoid
+ -- order of elaboration issues, replace them with their base
+ -- types. Note that address clauses can cause order of
+ -- elaboration problems because they are elaborated by the
+ -- back-end at the point of definition, and may mention
+ -- entities declared in between (as long as everything is
+ -- static). It is user-friendly to allow unchecked conversions
+ -- in this context.
+
+ if Nkind (Original_Node (Nod)) = N_Function_Call then
+ Set_Etype (Expression (Nod),
+ Base_Type (Etype (Expression (Nod))));
+ Set_Etype (Nod, Base_Type (Etype (Nod)));
+ end if;
+
+ when N_Function_Call =>
+ if not Is_Pure (Entity (Name (Nod))) then
+ Error_Msg_NE
+ ("invalid address clause for initialized object &!",
+ Nod, U_Ent);
+
+ Error_Msg_NE
+ ("\function & is not pure (RM 13.1(22))!",
+ Nod, Entity (Name (Nod)));
+
+ else
+ Check_List_Constants (Parameter_Associations (Nod));
+ end if;
+
+ when N_Parameter_Association =>
+ Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
+
+ when others =>
+ Error_Msg_NE
+ ("invalid address clause for initialized object &!",
+ Nod, U_Ent);
+ Error_Msg_NE
+ ("\must be constant defined before& (RM 13.1(22))!",
+ Nod, U_Ent);
+ end case;
+ end Check_Expr_Constants;
+
+ --------------------------
+ -- Check_List_Constants --
+ --------------------------
+
+ procedure Check_List_Constants (Lst : List_Id) is
+ Nod1 : Node_Id;
+
+ begin
+ if Present (Lst) then
+ Nod1 := First (Lst);
+ while Present (Nod1) loop
+ Check_Expr_Constants (Nod1);
+ Next (Nod1);
+ end loop;
+ end if;
+ end Check_List_Constants;
+
+ -- Start of processing for Check_Constant_Address_Clause
+
+ begin
+ -- If rep_clauses are to be ignored, no need for legality checks. In
+ -- particular, no need to pester user about rep clauses that violate
+ -- the rule on constant addresses, given that these clauses will be
+ -- removed by Freeze before they reach the back end.
+
+ if not Ignore_Rep_Clauses then
+ Check_Expr_Constants (Expr);
+ end if;
+ end Check_Constant_Address_Clause;
+
+ ----------------------------------------
+ -- Check_Record_Representation_Clause --
+ ----------------------------------------
+
+ procedure Check_Record_Representation_Clause (N : Node_Id) is
+ Loc : constant Source_Ptr := Sloc (N);
+ Ident : constant Node_Id := Identifier (N);
+ Rectype : Entity_Id;
+ Fent : Entity_Id;
+ CC : Node_Id;
+ Fbit : Uint;
+ Lbit : Uint;
+ Hbit : Uint := Uint_0;
+ Comp : Entity_Id;
+ Pcomp : Entity_Id;
+
+ Max_Bit_So_Far : Uint;
+ -- Records the maximum bit position so far. If all field positions
+ -- are monotonically increasing, then we can skip the circuit for
+ -- checking for overlap, since no overlap is possible.
+
+ Tagged_Parent : Entity_Id := Empty;
+ -- This is set in the case of a derived tagged type for which we have
+ -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
+ -- positioned by record representation clauses). In this case we must
+ -- check for overlap between components of this tagged type, and the
+ -- components of its parent. Tagged_Parent will point to this parent
+ -- type. For all other cases Tagged_Parent is left set to Empty.
+
+ Parent_Last_Bit : Uint;
+ -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
+ -- last bit position for any field in the parent type. We only need to
+ -- check overlap for fields starting below this point.
+
+ Overlap_Check_Required : Boolean;
+ -- Used to keep track of whether or not an overlap check is required
+
+ Overlap_Detected : Boolean := False;
+ -- Set True if an overlap is detected
+
+ Ccount : Natural := 0;
+ -- Number of component clauses in record rep clause
+
+ procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
+ -- Given two entities for record components or discriminants, checks
+ -- if they have overlapping component clauses and issues errors if so.
+
+ procedure Find_Component;
+ -- Finds component entity corresponding to current component clause (in
+ -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
+ -- start/stop bits for the field. If there is no matching component or
+ -- if the matching component does not have a component clause, then
+ -- that's an error and Comp is set to Empty, but no error message is
+ -- issued, since the message was already given. Comp is also set to
+ -- Empty if the current "component clause" is in fact a pragma.
+
+ -----------------------------
+ -- Check_Component_Overlap --
+ -----------------------------
+
+ procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
+ CC1 : constant Node_Id := Component_Clause (C1_Ent);
+ CC2 : constant Node_Id := Component_Clause (C2_Ent);
+
+ begin
+ if Present (CC1) and then Present (CC2) then
+
+ -- Exclude odd case where we have two tag fields in the same
+ -- record, both at location zero. This seems a bit strange, but
+ -- it seems to happen in some circumstances, perhaps on an error.
+
+ if Chars (C1_Ent) = Name_uTag
+ and then
+ Chars (C2_Ent) = Name_uTag
+ then
+ return;
+ end if;
+
+ -- Here we check if the two fields overlap
+
+ declare
+ S1 : constant Uint := Component_Bit_Offset (C1_Ent);
+ S2 : constant Uint := Component_Bit_Offset (C2_Ent);
+ E1 : constant Uint := S1 + Esize (C1_Ent);
+ E2 : constant Uint := S2 + Esize (C2_Ent);
+
+ begin
+ if E2 <= S1 or else E1 <= S2 then
+ null;
+ else
+ Error_Msg_Node_2 := Component_Name (CC2);
+ Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
+ Error_Msg_Node_1 := Component_Name (CC1);
+ Error_Msg_N
+ ("component& overlaps & #", Component_Name (CC1));
+ Overlap_Detected := True;
+ end if;
+ end;
+ end if;
+ end Check_Component_Overlap;
+
+ --------------------
+ -- Find_Component --
+ --------------------
+
+ procedure Find_Component is
+
+ procedure Search_Component (R : Entity_Id);
+ -- Search components of R for a match. If found, Comp is set.
+
+ ----------------------
+ -- Search_Component --
+ ----------------------
+
+ procedure Search_Component (R : Entity_Id) is
+ begin
+ Comp := First_Component_Or_Discriminant (R);
+ while Present (Comp) loop
+
+ -- Ignore error of attribute name for component name (we
+ -- already gave an error message for this, so no need to
+ -- complain here)
+
+ if Nkind (Component_Name (CC)) = N_Attribute_Reference then
+ null;
+ else
+ exit when Chars (Comp) = Chars (Component_Name (CC));
+ end if;
+
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+ end Search_Component;
+
+ -- Start of processing for Find_Component
+
+ begin
+ -- Return with Comp set to Empty if we have a pragma
+
+ if Nkind (CC) = N_Pragma then
+ Comp := Empty;
+ return;
+ end if;
+
+ -- Search current record for matching component
+
+ Search_Component (Rectype);
+
+ -- If not found, maybe component of base type that is absent from
+ -- statically constrained first subtype.
+
+ if No (Comp) then
+ Search_Component (Base_Type (Rectype));
+ end if;
+
+ -- If no component, or the component does not reference the component
+ -- clause in question, then there was some previous error for which
+ -- we already gave a message, so just return with Comp Empty.
+
+ if No (Comp)
+ or else Component_Clause (Comp) /= CC
+ then
+ Comp := Empty;
+
+ -- Normal case where we have a component clause
+
+ else
+ Fbit := Component_Bit_Offset (Comp);
+ Lbit := Fbit + Esize (Comp) - 1;
+ end if;
+ end Find_Component;
+
+ -- Start of processing for Check_Record_Representation_Clause
+
+ begin
+ Find_Type (Ident);
+ Rectype := Entity (Ident);
+
+ if Rectype = Any_Type then
+ return;
+ else
+ Rectype := Underlying_Type (Rectype);
+ end if;
+
+ -- See if we have a fully repped derived tagged type
+
+ declare
+ PS : constant Entity_Id := Parent_Subtype (Rectype);
+
+ begin
+ if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
+ Tagged_Parent := PS;
+
+ -- Find maximum bit of any component of the parent type
+
+ Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
+ Pcomp := First_Entity (Tagged_Parent);
+ while Present (Pcomp) loop
+ if Ekind_In (Pcomp, E_Discriminant, E_Component) then
+ if Component_Bit_Offset (Pcomp) /= No_Uint
+ and then Known_Static_Esize (Pcomp)
+ then
+ Parent_Last_Bit :=
+ UI_Max
+ (Parent_Last_Bit,
+ Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
+ end if;
+
+ Next_Entity (Pcomp);
+ end if;
+ end loop;
+ end if;
+ end;
+
+ -- All done if no component clauses
+
+ CC := First (Component_Clauses (N));
+
+ if No (CC) then
+ return;
+ end if;
+
+ -- If a tag is present, then create a component clause that places it
+ -- at the start of the record (otherwise gigi may place it after other
+ -- fields that have rep clauses).
+
+ Fent := First_Entity (Rectype);
+
+ if Nkind (Fent) = N_Defining_Identifier
+ and then Chars (Fent) = Name_uTag
+ then
+ Set_Component_Bit_Offset (Fent, Uint_0);
+ Set_Normalized_Position (Fent, Uint_0);
+ Set_Normalized_First_Bit (Fent, Uint_0);
+ Set_Normalized_Position_Max (Fent, Uint_0);
+ Init_Esize (Fent, System_Address_Size);
+
+ Set_Component_Clause (Fent,
+ Make_Component_Clause (Loc,
+ Component_Name => Make_Identifier (Loc, Name_uTag),
+
+ Position => Make_Integer_Literal (Loc, Uint_0),
+ First_Bit => Make_Integer_Literal (Loc, Uint_0),
+ Last_Bit =>
+ Make_Integer_Literal (Loc,
+ UI_From_Int (System_Address_Size))));
+
+ Ccount := Ccount + 1;
+ end if;
+
+ Max_Bit_So_Far := Uint_Minus_1;
+ Overlap_Check_Required := False;
+
+ -- Process the component clauses
+
+ while Present (CC) loop
+ Find_Component;
+
+ if Present (Comp) then
+ Ccount := Ccount + 1;
+
+ -- We need a full overlap check if record positions non-monotonic
+
+ if Fbit <= Max_Bit_So_Far then
+ Overlap_Check_Required := True;
+ end if;
+
+ Max_Bit_So_Far := Lbit;
+
+ -- Check bit position out of range of specified size
+
+ if Has_Size_Clause (Rectype)
+ and then Esize (Rectype) <= Lbit
+ then
+ Error_Msg_N
+ ("bit number out of range of specified size",
+ Last_Bit (CC));
+
+ -- Check for overlap with tag field
+
+ else
+ if Is_Tagged_Type (Rectype)
+ and then Fbit < System_Address_Size
+ then
+ Error_Msg_NE
+ ("component overlaps tag field of&",
+ Component_Name (CC), Rectype);
+ Overlap_Detected := True;
+ end if;
+
+ if Hbit < Lbit then
+ Hbit := Lbit;
+ end if;
+ end if;
+
+ -- Check parent overlap if component might overlap parent field
+
+ if Present (Tagged_Parent)
+ and then Fbit <= Parent_Last_Bit
+ then
+ Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
+ while Present (Pcomp) loop
+ if not Is_Tag (Pcomp)
+ and then Chars (Pcomp) /= Name_uParent
+ then
+ Check_Component_Overlap (Comp, Pcomp);
+ end if;
+
+ Next_Component_Or_Discriminant (Pcomp);
+ end loop;
+ end if;
+ end if;
+
+ Next (CC);
+ end loop;
+
+ -- Now that we have processed all the component clauses, check for
+ -- overlap. We have to leave this till last, since the components can
+ -- appear in any arbitrary order in the representation clause.
+
+ -- We do not need this check if all specified ranges were monotonic,
+ -- as recorded by Overlap_Check_Required being False at this stage.
+
+ -- This first section checks if there are any overlapping entries at
+ -- all. It does this by sorting all entries and then seeing if there are
+ -- any overlaps. If there are none, then that is decisive, but if there
+ -- are overlaps, they may still be OK (they may result from fields in
+ -- different variants).
+
+ if Overlap_Check_Required then
+ Overlap_Check1 : declare
+
+ OC_Fbit : array (0 .. Ccount) of Uint;
+ -- First-bit values for component clauses, the value is the offset
+ -- of the first bit of the field from start of record. The zero
+ -- entry is for use in sorting.
+
+ OC_Lbit : array (0 .. Ccount) of Uint;
+ -- Last-bit values for component clauses, the value is the offset
+ -- of the last bit of the field from start of record. The zero
+ -- entry is for use in sorting.
+
+ OC_Count : Natural := 0;
+ -- Count of entries in OC_Fbit and OC_Lbit
+
+ function OC_Lt (Op1, Op2 : Natural) return Boolean;
+ -- Compare routine for Sort
+
+ procedure OC_Move (From : Natural; To : Natural);
+ -- Move routine for Sort
+
+ package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
+
+ -----------
+ -- OC_Lt --
+ -----------
+
+ function OC_Lt (Op1, Op2 : Natural) return Boolean is
+ begin
+ return OC_Fbit (Op1) < OC_Fbit (Op2);
+ end OC_Lt;
+
+ -------------
+ -- OC_Move --
+ -------------
+
+ procedure OC_Move (From : Natural; To : Natural) is
+ begin
+ OC_Fbit (To) := OC_Fbit (From);
+ OC_Lbit (To) := OC_Lbit (From);
+ end OC_Move;
+
+ -- Start of processing for Overlap_Check
+
+ begin
+ CC := First (Component_Clauses (N));
+ while Present (CC) loop
+
+ -- Exclude component clause already marked in error
+
+ if not Error_Posted (CC) then
+ Find_Component;
+
+ if Present (Comp) then
+ OC_Count := OC_Count + 1;
+ OC_Fbit (OC_Count) := Fbit;
+ OC_Lbit (OC_Count) := Lbit;
+ end if;
+ end if;
+
+ Next (CC);
+ end loop;
+
+ Sorting.Sort (OC_Count);
+
+ Overlap_Check_Required := False;
+ for J in 1 .. OC_Count - 1 loop
+ if OC_Lbit (J) >= OC_Fbit (J + 1) then
+ Overlap_Check_Required := True;
+ exit;
+ end if;
+ end loop;
+ end Overlap_Check1;
+ end if;
+
+ -- If Overlap_Check_Required is still True, then we have to do the full
+ -- scale overlap check, since we have at least two fields that do
+ -- overlap, and we need to know if that is OK since they are in
+ -- different variant, or whether we have a definite problem.
+
+ if Overlap_Check_Required then
+ Overlap_Check2 : declare
+ C1_Ent, C2_Ent : Entity_Id;
+ -- Entities of components being checked for overlap
+
+ Clist : Node_Id;
+ -- Component_List node whose Component_Items are being checked
+
+ Citem : Node_Id;
+ -- Component declaration for component being checked
+
+ begin
+ C1_Ent := First_Entity (Base_Type (Rectype));
+
+ -- Loop through all components in record. For each component check
+ -- for overlap with any of the preceding elements on the component
+ -- list containing the component and also, if the component is in
+ -- a variant, check against components outside the case structure.
+ -- This latter test is repeated recursively up the variant tree.
+
+ Main_Component_Loop : while Present (C1_Ent) loop
+ if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
+ goto Continue_Main_Component_Loop;
+ end if;
+
+ -- Skip overlap check if entity has no declaration node. This
+ -- happens with discriminants in constrained derived types.
+ -- Possibly we are missing some checks as a result, but that
+ -- does not seem terribly serious.
+
+ if No (Declaration_Node (C1_Ent)) then
+ goto Continue_Main_Component_Loop;
+ end if;
+
+ Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
+
+ -- Loop through component lists that need checking. Check the
+ -- current component list and all lists in variants above us.
+
+ Component_List_Loop : loop
+
+ -- If derived type definition, go to full declaration
+ -- If at outer level, check discriminants if there are any.
+
+ if Nkind (Clist) = N_Derived_Type_Definition then
+ Clist := Parent (Clist);
+ end if;
+
+ -- Outer level of record definition, check discriminants
+
+ if Nkind_In (Clist, N_Full_Type_Declaration,
+ N_Private_Type_Declaration)
+ then
+ if Has_Discriminants (Defining_Identifier (Clist)) then
+ C2_Ent :=
+ First_Discriminant (Defining_Identifier (Clist));
+ while Present (C2_Ent) loop
+ exit when C1_Ent = C2_Ent;
+ Check_Component_Overlap (C1_Ent, C2_Ent);
+ Next_Discriminant (C2_Ent);
+ end loop;
+ end if;
+
+ -- Record extension case
+
+ elsif Nkind (Clist) = N_Derived_Type_Definition then
+ Clist := Empty;
+
+ -- Otherwise check one component list
+
+ else
+ Citem := First (Component_Items (Clist));
+ while Present (Citem) loop
+ if Nkind (Citem) = N_Component_Declaration then
+ C2_Ent := Defining_Identifier (Citem);
+ exit when C1_Ent = C2_Ent;
+ Check_Component_Overlap (C1_Ent, C2_Ent);
+ end if;
+
+ Next (Citem);
+ end loop;
+ end if;
+
+ -- Check for variants above us (the parent of the Clist can
+ -- be a variant, in which case its parent is a variant part,
+ -- and the parent of the variant part is a component list
+ -- whose components must all be checked against the current
+ -- component for overlap).
+
+ if Nkind (Parent (Clist)) = N_Variant then
+ Clist := Parent (Parent (Parent (Clist)));
+
+ -- Check for possible discriminant part in record, this
+ -- is treated essentially as another level in the
+ -- recursion. For this case the parent of the component
+ -- list is the record definition, and its parent is the
+ -- full type declaration containing the discriminant
+ -- specifications.
+
+ elsif Nkind (Parent (Clist)) = N_Record_Definition then
+ Clist := Parent (Parent ((Clist)));
+
+ -- If neither of these two cases, we are at the top of
+ -- the tree.
+
+ else
+ exit Component_List_Loop;
+ end if;
+ end loop Component_List_Loop;
+
+ <<Continue_Main_Component_Loop>>
+ Next_Entity (C1_Ent);
+
+ end loop Main_Component_Loop;
+ end Overlap_Check2;
+ end if;
+
+ -- The following circuit deals with warning on record holes (gaps). We
+ -- skip this check if overlap was detected, since it makes sense for the
+ -- programmer to fix this illegality before worrying about warnings.
+
+ if not Overlap_Detected and Warn_On_Record_Holes then
+ Record_Hole_Check : declare
+ Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype));
+ -- Full declaration of record type
+
+ procedure Check_Component_List
+ (CL : Node_Id;
+ Sbit : Uint;
+ DS : List_Id);
+ -- Check component list CL for holes. The starting bit should be
+ -- Sbit. which is zero for the main record component list and set
+ -- appropriately for recursive calls for variants. DS is set to
+ -- a list of discriminant specifications to be included in the
+ -- consideration of components. It is No_List if none to consider.
+
+ --------------------------
+ -- Check_Component_List --
+ --------------------------
+
+ procedure Check_Component_List
+ (CL : Node_Id;
+ Sbit : Uint;
+ DS : List_Id)
+ is
+ Compl : Integer;
+
+ begin
+ Compl := Integer (List_Length (Component_Items (CL)));
+
+ if DS /= No_List then
+ Compl := Compl + Integer (List_Length (DS));
+ end if;
+
+ declare
+ Comps : array (Natural range 0 .. Compl) of Entity_Id;
+ -- Gather components (zero entry is for sort routine)
+
+ Ncomps : Natural := 0;
+ -- Number of entries stored in Comps (starting at Comps (1))
+
+ Citem : Node_Id;
+ -- One component item or discriminant specification
+
+ Nbit : Uint;
+ -- Starting bit for next component
+
+ CEnt : Entity_Id;
+ -- Component entity
+
+ Variant : Node_Id;
+ -- One variant
+
+ function Lt (Op1, Op2 : Natural) return Boolean;
+ -- Compare routine for Sort
+
+ procedure Move (From : Natural; To : Natural);
+ -- Move routine for Sort
+
+ package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
+
+ --------
+ -- Lt --
+ --------
+
+ function Lt (Op1, Op2 : Natural) return Boolean is
+ begin
+ return Component_Bit_Offset (Comps (Op1))
+ <
+ Component_Bit_Offset (Comps (Op2));
+ end Lt;
+
+ ----------
+ -- Move --
+ ----------
+
+ procedure Move (From : Natural; To : Natural) is
+ begin
+ Comps (To) := Comps (From);
+ end Move;
+
+ begin
+ -- Gather discriminants into Comp
+
+ if DS /= No_List then
+ Citem := First (DS);
+ while Present (Citem) loop
+ if Nkind (Citem) = N_Discriminant_Specification then
+ declare
+ Ent : constant Entity_Id :=
+ Defining_Identifier (Citem);
+ begin
+ if Ekind (Ent) = E_Discriminant then
+ Ncomps := Ncomps + 1;
+ Comps (Ncomps) := Ent;
+ end if;
+ end;
+ end if;
+
+ Next (Citem);
+ end loop;
+ end if;
+
+ -- Gather component entities into Comp
+
+ Citem := First (Component_Items (CL));
+ while Present (Citem) loop
+ if Nkind (Citem) = N_Component_Declaration then
+ Ncomps := Ncomps + 1;
+ Comps (Ncomps) := Defining_Identifier (Citem);
+ end if;
+
+ Next (Citem);
+ end loop;
+
+ -- Now sort the component entities based on the first bit.
+ -- Note we already know there are no overlapping components.
+
+ Sorting.Sort (Ncomps);
+
+ -- Loop through entries checking for holes
+
+ Nbit := Sbit;
+ for J in 1 .. Ncomps loop
+ CEnt := Comps (J);
+ Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
+
+ if Error_Msg_Uint_1 > 0 then
+ Error_Msg_NE
+ ("?^-bit gap before component&",
+ Component_Name (Component_Clause (CEnt)), CEnt);
+ end if;
+
+ Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
+ end loop;
+
+ -- Process variant parts recursively if present
+
+ if Present (Variant_Part (CL)) then
+ Variant := First (Variants (Variant_Part (CL)));
+ while Present (Variant) loop
+ Check_Component_List
+ (Component_List (Variant), Nbit, No_List);
+ Next (Variant);
+ end loop;
+ end if;
+ end;
+ end Check_Component_List;
+
+ -- Start of processing for Record_Hole_Check
+
+ begin
+ declare
+ Sbit : Uint;
+
+ begin
+ if Is_Tagged_Type (Rectype) then
+ Sbit := UI_From_Int (System_Address_Size);
+ else
+ Sbit := Uint_0;
+ end if;
+
+ if Nkind (Decl) = N_Full_Type_Declaration
+ and then Nkind (Type_Definition (Decl)) = N_Record_Definition
+ then
+ Check_Component_List
+ (Component_List (Type_Definition (Decl)),
+ Sbit,
+ Discriminant_Specifications (Decl));
+ end if;
+ end;
+ end Record_Hole_Check;
+ end if;
+
+ -- For records that have component clauses for all components, and whose
+ -- size is less than or equal to 32, we need to know the size in the
+ -- front end to activate possible packed array processing where the
+ -- component type is a record.
+
+ -- At this stage Hbit + 1 represents the first unused bit from all the
+ -- component clauses processed, so if the component clauses are
+ -- complete, then this is the length of the record.
+
+ -- For records longer than System.Storage_Unit, and for those where not
+ -- all components have component clauses, the back end determines the
+ -- length (it may for example be appropriate to round up the size
+ -- to some convenient boundary, based on alignment considerations, etc).
+
+ if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
+
+ -- Nothing to do if at least one component has no component clause
+
+ Comp := First_Component_Or_Discriminant (Rectype);
+ while Present (Comp) loop
+ exit when No (Component_Clause (Comp));
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+
+ -- If we fall out of loop, all components have component clauses
+ -- and so we can set the size to the maximum value.
+
+ if No (Comp) then
+ Set_RM_Size (Rectype, Hbit + 1);
+ end if;
+ end if;
+ end Check_Record_Representation_Clause;
+
+ ----------------
+ -- Check_Size --
+ ----------------
+
+ procedure Check_Size
+ (N : Node_Id;
+ T : Entity_Id;
+ Siz : Uint;
+ Biased : out Boolean)
+ is
+ UT : constant Entity_Id := Underlying_Type (T);
+ M : Uint;
+
+ begin
+ Biased := False;
+
+ -- Dismiss cases for generic types or types with previous errors
+
+ if No (UT)
+ or else UT = Any_Type
+ or else Is_Generic_Type (UT)
+ or else Is_Generic_Type (Root_Type (UT))
+ then
+ return;
+
+ -- Check case of bit packed array
+
+ elsif Is_Array_Type (UT)
+ and then Known_Static_Component_Size (UT)
+ and then Is_Bit_Packed_Array (UT)
+ then
+ declare
+ Asiz : Uint;
+ Indx : Node_Id;
+ Ityp : Entity_Id;
+
+ begin
+ Asiz := Component_Size (UT);
+ Indx := First_Index (UT);
+ loop
+ Ityp := Etype (Indx);
+
+ -- If non-static bound, then we are not in the business of
+ -- trying to check the length, and indeed an error will be
+ -- issued elsewhere, since sizes of non-static array types
+ -- cannot be set implicitly or explicitly.
+
+ if not Is_Static_Subtype (Ityp) then
+ return;
+ end if;
+
+ -- Otherwise accumulate next dimension
+
+ Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
+ Expr_Value (Type_Low_Bound (Ityp)) +
+ Uint_1);
+
+ Next_Index (Indx);
+ exit when No (Indx);
+ end loop;
+
+ if Asiz <= Siz then
+ return;
+ else
+ Error_Msg_Uint_1 := Asiz;
+ Error_Msg_NE
+ ("size for& too small, minimum allowed is ^", N, T);
+ Set_Esize (T, Asiz);
+ Set_RM_Size (T, Asiz);
+ end if;
+ end;
+
+ -- All other composite types are ignored
+
+ elsif Is_Composite_Type (UT) then
+ return;
+
+ -- For fixed-point types, don't check minimum if type is not frozen,
+ -- since we don't know all the characteristics of the type that can
+ -- affect the size (e.g. a specified small) till freeze time.
+
+ elsif Is_Fixed_Point_Type (UT)
+ and then not Is_Frozen (UT)
+ then
+ null;
+
+ -- Cases for which a minimum check is required
+
+ else
+ -- Ignore if specified size is correct for the type
+
+ if Known_Esize (UT) and then Siz = Esize (UT) then
+ return;
+ end if;
+
+ -- Otherwise get minimum size
+
+ M := UI_From_Int (Minimum_Size (UT));
+
+ if Siz < M then
+
+ -- Size is less than minimum size, but one possibility remains
+ -- that we can manage with the new size if we bias the type.
+
+ M := UI_From_Int (Minimum_Size (UT, Biased => True));
+
+ if Siz < M then
+ Error_Msg_Uint_1 := M;
+ Error_Msg_NE
+ ("size for& too small, minimum allowed is ^", N, T);
+ Set_Esize (T, M);
+ Set_RM_Size (T, M);
+ else
+ Biased := True;
+ end if;
+ end if;
+ end if;
+ end Check_Size;
+
+ -------------------------
+ -- Get_Alignment_Value --
+ -------------------------
+
+ function Get_Alignment_Value (Expr : Node_Id) return Uint is
+ Align : constant Uint := Static_Integer (Expr);
+
+ begin
+ if Align = No_Uint then
+ return No_Uint;
+
+ elsif Align <= 0 then
+ Error_Msg_N ("alignment value must be positive", Expr);
+ return No_Uint;
+
+ else
+ for J in Int range 0 .. 64 loop
+ declare
+ M : constant Uint := Uint_2 ** J;
+
+ begin
+ exit when M = Align;
+
+ if M > Align then
+ Error_Msg_N
+ ("alignment value must be power of 2", Expr);
+ return No_Uint;
+ end if;
+ end;
+ end loop;
+
+ return Align;
+ end if;
+ end Get_Alignment_Value;
+
+ ----------------
+ -- Initialize --
+ ----------------
+
+ procedure Initialize is
+ begin
+ Address_Clause_Checks.Init;
+ Independence_Checks.Init;
+ Unchecked_Conversions.Init;
+ end Initialize;
+
+ -------------------------
+ -- Is_Operational_Item --
+ -------------------------
+
+ function Is_Operational_Item (N : Node_Id) return Boolean is
+ begin
+ if Nkind (N) /= N_Attribute_Definition_Clause then
+ return False;
+ else
+ declare
+ Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
+ begin
+ return Id = Attribute_Input
+ or else Id = Attribute_Output
+ or else Id = Attribute_Read
+ or else Id = Attribute_Write
+ or else Id = Attribute_External_Tag;
+ end;
+ end if;
+ end Is_Operational_Item;
+
+ ------------------
+ -- Minimum_Size --
+ ------------------
+
+ function Minimum_Size
+ (T : Entity_Id;
+ Biased : Boolean := False) return Nat
+ is
+ Lo : Uint := No_Uint;
+ Hi : Uint := No_Uint;
+ LoR : Ureal := No_Ureal;
+ HiR : Ureal := No_Ureal;
+ LoSet : Boolean := False;
+ HiSet : Boolean := False;
+ B : Uint;
+ S : Nat;
+ Ancest : Entity_Id;
+ R_Typ : constant Entity_Id := Root_Type (T);
+
+ begin
+ -- If bad type, return 0
+
+ if T = Any_Type then
+ return 0;
+
+ -- For generic types, just return zero. There cannot be any legitimate
+ -- need to know such a size, but this routine may be called with a
+ -- generic type as part of normal processing.
+
+ elsif Is_Generic_Type (R_Typ)
+ or else R_Typ = Any_Type
+ then
+ return 0;
+
+ -- Access types. Normally an access type cannot have a size smaller
+ -- than the size of System.Address. The exception is on VMS, where
+ -- we have short and long addresses, and it is possible for an access
+ -- type to have a short address size (and thus be less than the size
+ -- of System.Address itself). We simply skip the check for VMS, and
+ -- leave it to the back end to do the check.
+
+ elsif Is_Access_Type (T) then
+ if OpenVMS_On_Target then
+ return 0;
+ else
+ return System_Address_Size;
+ end if;
+
+ -- Floating-point types
+
+ elsif Is_Floating_Point_Type (T) then
+ return UI_To_Int (Esize (R_Typ));
+
+ -- Discrete types
+
+ elsif Is_Discrete_Type (T) then
+
+ -- The following loop is looking for the nearest compile time known
+ -- bounds following the ancestor subtype chain. The idea is to find
+ -- the most restrictive known bounds information.
+
+ Ancest := T;
+ loop
+ if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
+ return 0;
+ end if;
+
+ if not LoSet then
+ if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
+ Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
+ LoSet := True;
+ exit when HiSet;
+ end if;
+ end if;
+
+ if not HiSet then
+ if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
+ Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
+ HiSet := True;
+ exit when LoSet;
+ end if;
+ end if;
+
+ Ancest := Ancestor_Subtype (Ancest);
+
+ if No (Ancest) then
+ Ancest := Base_Type (T);
+
+ if Is_Generic_Type (Ancest) then
+ return 0;
+ end if;
+ end if;
+ end loop;
+
+ -- Fixed-point types. We can't simply use Expr_Value to get the
+ -- Corresponding_Integer_Value values of the bounds, since these do not
+ -- get set till the type is frozen, and this routine can be called
+ -- before the type is frozen. Similarly the test for bounds being static
+ -- needs to include the case where we have unanalyzed real literals for
+ -- the same reason.
+
+ elsif Is_Fixed_Point_Type (T) then
+
+ -- The following loop is looking for the nearest compile time known
+ -- bounds following the ancestor subtype chain. The idea is to find
+ -- the most restrictive known bounds information.
+
+ Ancest := T;
+ loop
+ if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
+ return 0;
+ end if;
+
+ -- Note: In the following two tests for LoSet and HiSet, it may
+ -- seem redundant to test for N_Real_Literal here since normally
+ -- one would assume that the test for the value being known at
+ -- compile time includes this case. However, there is a glitch.
+ -- If the real literal comes from folding a non-static expression,
+ -- then we don't consider any non- static expression to be known
+ -- at compile time if we are in configurable run time mode (needed
+ -- in some cases to give a clearer definition of what is and what
+ -- is not accepted). So the test is indeed needed. Without it, we
+ -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
+
+ if not LoSet then
+ if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
+ or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
+ then
+ LoR := Expr_Value_R (Type_Low_Bound (Ancest));
+ LoSet := True;
+ exit when HiSet;
+ end if;
+ end if;
+
+ if not HiSet then
+ if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
+ or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
+ then
+ HiR := Expr_Value_R (Type_High_Bound (Ancest));
+ HiSet := True;
+ exit when LoSet;
+ end if;
+ end if;
+
+ Ancest := Ancestor_Subtype (Ancest);
+
+ if No (Ancest) then
+ Ancest := Base_Type (T);
+
+ if Is_Generic_Type (Ancest) then
+ return 0;
+ end if;
+ end if;
+ end loop;
+
+ Lo := UR_To_Uint (LoR / Small_Value (T));
+ Hi := UR_To_Uint (HiR / Small_Value (T));
+
+ -- No other types allowed
+
+ else
+ raise Program_Error;
+ end if;
+
+ -- Fall through with Hi and Lo set. Deal with biased case
+
+ if (Biased
+ and then not Is_Fixed_Point_Type (T)
+ and then not (Is_Enumeration_Type (T)
+ and then Has_Non_Standard_Rep (T)))
+ or else Has_Biased_Representation (T)
+ then
+ Hi := Hi - Lo;
+ Lo := Uint_0;
+ end if;
+
+ -- Signed case. Note that we consider types like range 1 .. -1 to be
+ -- signed for the purpose of computing the size, since the bounds have
+ -- to be accommodated in the base type.
+
+ if Lo < 0 or else Hi < 0 then
+ S := 1;
+ B := Uint_1;
+
+ -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
+ -- Note that we accommodate the case where the bounds cross. This
+ -- can happen either because of the way the bounds are declared
+ -- or because of the algorithm in Freeze_Fixed_Point_Type.
+
+ while Lo < -B
+ or else Hi < -B
+ or else Lo >= B
+ or else Hi >= B
+ loop
+ B := Uint_2 ** S;
+ S := S + 1;
+ end loop;
+
+ -- Unsigned case
+
+ else
+ -- If both bounds are positive, make sure that both are represen-
+ -- table in the case where the bounds are crossed. This can happen
+ -- either because of the way the bounds are declared, or because of
+ -- the algorithm in Freeze_Fixed_Point_Type.
+
+ if Lo > Hi then
+ Hi := Lo;
+ end if;
+
+ -- S = size, (can accommodate 0 .. (2**size - 1))
+
+ S := 0;
+ while Hi >= Uint_2 ** S loop
+ S := S + 1;
+ end loop;
+ end if;
+
+ return S;
+ end Minimum_Size;
+
+ ---------------------------
+ -- New_Stream_Subprogram --
+ ---------------------------
+
+ procedure New_Stream_Subprogram
+ (N : Node_Id;
+ Ent : Entity_Id;
+ Subp : Entity_Id;
+ Nam : TSS_Name_Type)
+ is
+ Loc : constant Source_Ptr := Sloc (N);
+ Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
+ Subp_Id : Entity_Id;
+ Subp_Decl : Node_Id;
+ F : Entity_Id;
+ Etyp : Entity_Id;
+
+ Defer_Declaration : constant Boolean :=
+ Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
+ -- For a tagged type, there is a declaration for each stream attribute
+ -- at the freeze point, and we must generate only a completion of this
+ -- declaration. We do the same for private types, because the full view
+ -- might be tagged. Otherwise we generate a declaration at the point of
+ -- the attribute definition clause.
+
+ function Build_Spec return Node_Id;
+ -- Used for declaration and renaming declaration, so that this is
+ -- treated as a renaming_as_body.
+
+ ----------------
+ -- Build_Spec --
+ ----------------
+
+ function Build_Spec return Node_Id is
+ Out_P : constant Boolean := (Nam = TSS_Stream_Read);
+ Formals : List_Id;
+ Spec : Node_Id;
+ T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
+
+ begin
+ Subp_Id := Make_Defining_Identifier (Loc, Sname);
+
+ -- S : access Root_Stream_Type'Class
+
+ Formals := New_List (
+ Make_Parameter_Specification (Loc,
+ Defining_Identifier =>
+ Make_Defining_Identifier (Loc, Name_S),
+ Parameter_Type =>
+ Make_Access_Definition (Loc,
+ Subtype_Mark =>
+ New_Reference_To (
+ Designated_Type (Etype (F)), Loc))));
+
+ if Nam = TSS_Stream_Input then
+ Spec := Make_Function_Specification (Loc,
+ Defining_Unit_Name => Subp_Id,
+ Parameter_Specifications => Formals,
+ Result_Definition => T_Ref);
+ else
+ -- V : [out] T
+
+ Append_To (Formals,
+ Make_Parameter_Specification (Loc,
+ Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
+ Out_Present => Out_P,
+ Parameter_Type => T_Ref));
+
+ Spec :=
+ Make_Procedure_Specification (Loc,
+ Defining_Unit_Name => Subp_Id,
+ Parameter_Specifications => Formals);
+ end if;
+
+ return Spec;
+ end Build_Spec;
+
+ -- Start of processing for New_Stream_Subprogram
+
+ begin
+ F := First_Formal (Subp);
+
+ if Ekind (Subp) = E_Procedure then
+ Etyp := Etype (Next_Formal (F));
+ else
+ Etyp := Etype (Subp);
+ end if;
+
+ -- Prepare subprogram declaration and insert it as an action on the
+ -- clause node. The visibility for this entity is used to test for
+ -- visibility of the attribute definition clause (in the sense of
+ -- 8.3(23) as amended by AI-195).
+
+ if not Defer_Declaration then
+ Subp_Decl :=
+ Make_Subprogram_Declaration (Loc,
+ Specification => Build_Spec);
+
+ -- For a tagged type, there is always a visible declaration for each
+ -- stream TSS (it is a predefined primitive operation), and the
+ -- completion of this declaration occurs at the freeze point, which is
+ -- not always visible at places where the attribute definition clause is
+ -- visible. So, we create a dummy entity here for the purpose of
+ -- tracking the visibility of the attribute definition clause itself.
+
+ else
+ Subp_Id :=
+ Make_Defining_Identifier (Loc, New_External_Name (Sname, 'V'));
+ Subp_Decl :=
+ Make_Object_Declaration (Loc,
+ Defining_Identifier => Subp_Id,
+ Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
+ end if;
+
+ Insert_Action (N, Subp_Decl);
+ Set_Entity (N, Subp_Id);
+
+ Subp_Decl :=
+ Make_Subprogram_Renaming_Declaration (Loc,
+ Specification => Build_Spec,
+ Name => New_Reference_To (Subp, Loc));
+
+ if Defer_Declaration then
+ Set_TSS (Base_Type (Ent), Subp_Id);
+ else
+ Insert_Action (N, Subp_Decl);
+ Copy_TSS (Subp_Id, Base_Type (Ent));
+ end if;
+ end New_Stream_Subprogram;
+
+ ------------------------
+ -- Rep_Item_Too_Early --
+ ------------------------
+
+ function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
+ begin
+ -- Cannot apply non-operational rep items to generic types
+
+ if Is_Operational_Item (N) then
+ return False;
+
+ elsif Is_Type (T)
+ and then Is_Generic_Type (Root_Type (T))
+ then
+ Error_Msg_N ("representation item not allowed for generic type", N);
+ return True;
+ end if;
+
+ -- Otherwise check for incomplete type
+
+ if Is_Incomplete_Or_Private_Type (T)
+ and then No (Underlying_Type (T))
+ then
+ Error_Msg_N
+ ("representation item must be after full type declaration", N);
+ return True;
+
+ -- If the type has incomplete components, a representation clause is
+ -- illegal but stream attributes and Convention pragmas are correct.
+
+ elsif Has_Private_Component (T) then
+ if Nkind (N) = N_Pragma then
+ return False;
+ else
+ Error_Msg_N
+ ("representation item must appear after type is fully defined",
+ N);
+ return True;
+ end if;
+ else
+ return False;
+ end if;
+ end Rep_Item_Too_Early;
+
+ -----------------------
+ -- Rep_Item_Too_Late --
+ -----------------------
+
+ function Rep_Item_Too_Late
+ (T : Entity_Id;
+ N : Node_Id;
+ FOnly : Boolean := False) return Boolean
+ is
+ S : Entity_Id;
+ Parent_Type : Entity_Id;
+
+ procedure Too_Late;
+ -- Output the too late message. Note that this is not considered a
+ -- serious error, since the effect is simply that we ignore the
+ -- representation clause in this case.
+
+ --------------
+ -- Too_Late --
+ --------------
+
+ procedure Too_Late is
+ begin
+ Error_Msg_N ("|representation item appears too late!", N);
+ end Too_Late;
+
+ -- Start of processing for Rep_Item_Too_Late
+
+ begin
+ -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
+ -- types, which may be frozen if they appear in a representation clause
+ -- for a local type.
+
+ if Is_Frozen (T)
+ and then not From_With_Type (T)
+ then
+ Too_Late;
+ S := First_Subtype (T);
+
+ if Present (Freeze_Node (S)) then
+ Error_Msg_NE
+ ("?no more representation items for }", Freeze_Node (S), S);
+ end if;
+
+ return True;
+
+ -- Check for case of non-tagged derived type whose parent either has
+ -- primitive operations, or is a by reference type (RM 13.1(10)).
+
+ elsif Is_Type (T)
+ and then not FOnly
+ and then Is_Derived_Type (T)
+ and then not Is_Tagged_Type (T)
+ then
+ Parent_Type := Etype (Base_Type (T));
+
+ if Has_Primitive_Operations (Parent_Type) then
+ Too_Late;
+ Error_Msg_NE
+ ("primitive operations already defined for&!", N, Parent_Type);
+ return True;
+
+ elsif Is_By_Reference_Type (Parent_Type) then
+ Too_Late;
+ Error_Msg_NE
+ ("parent type & is a by reference type!", N, Parent_Type);
+ return True;
+ end if;
+ end if;
+
+ -- No error, link item into head of chain of rep items for the entity,
+ -- but avoid chaining if we have an overloadable entity, and the pragma
+ -- is one that can apply to multiple overloaded entities.
+
+ if Is_Overloadable (T)
+ and then Nkind (N) = N_Pragma
+ then
+ declare
+ Pname : constant Name_Id := Pragma_Name (N);
+ begin
+ if Pname = Name_Convention or else
+ Pname = Name_Import or else
+ Pname = Name_Export or else
+ Pname = Name_External or else
+ Pname = Name_Interface
+ then
+ return False;
+ end if;
+ end;
+ end if;
+
+ Record_Rep_Item (T, N);
+ return False;
+ end Rep_Item_Too_Late;
+
+ -------------------------------------
+ -- Replace_Type_References_Generic --
+ -------------------------------------
+
+ procedure Replace_Type_References_Generic (N : Node_Id; TName : Name_Id) is
+
+ function Replace_Node (N : Node_Id) return Traverse_Result;
+ -- Processes a single node in the traversal procedure below, checking
+ -- if node N should be replaced, and if so, doing the replacement.
+
+ procedure Replace_Type_Refs is new Traverse_Proc (Replace_Node);
+ -- This instantiation provides the body of Replace_Type_References
+
+ ------------------
+ -- Replace_Node --
+ ------------------
+
+ function Replace_Node (N : Node_Id) return Traverse_Result is
+ S : Entity_Id;
+ P : Node_Id;
+
+ begin
+ -- Case of identifier
+
+ if Nkind (N) = N_Identifier then
+
+ -- If not the type name, all done with this node
+
+ if Chars (N) /= TName then
+ return Skip;
+
+ -- Otherwise do the replacement and we are done with this node
+
+ else
+ Replace_Type_Reference (N);
+ return Skip;
+ end if;
+
+ -- Case of selected component (which is what a qualification
+ -- looks like in the unanalyzed tree, which is what we have.
+
+ elsif Nkind (N) = N_Selected_Component then
+
+ -- If selector name is not our type, keeping going (we might
+ -- still have an occurrence of the type in the prefix).
+
+ if Nkind (Selector_Name (N)) /= N_Identifier
+ or else Chars (Selector_Name (N)) /= TName
+ then
+ return OK;
+
+ -- Selector name is our type, check qualification
+
+ else
+ -- Loop through scopes and prefixes, doing comparison
+
+ S := Current_Scope;
+ P := Prefix (N);
+ loop
+ -- Continue if no more scopes or scope with no name
+
+ if No (S) or else Nkind (S) not in N_Has_Chars then
+ return OK;
+ end if;
+
+ -- Do replace if prefix is an identifier matching the
+ -- scope that we are currently looking at.
+
+ if Nkind (P) = N_Identifier
+ and then Chars (P) = Chars (S)
+ then
+ Replace_Type_Reference (N);
+ return Skip;
+ end if;
+
+ -- Go check scope above us if prefix is itself of the
+ -- form of a selected component, whose selector matches
+ -- the scope we are currently looking at.
+
+ if Nkind (P) = N_Selected_Component
+ and then Nkind (Selector_Name (P)) = N_Identifier
+ and then Chars (Selector_Name (P)) = Chars (S)
+ then
+ S := Scope (S);
+ P := Prefix (P);
+
+ -- For anything else, we don't have a match, so keep on
+ -- going, there are still some weird cases where we may
+ -- still have a replacement within the prefix.
+
+ else
+ return OK;
+ end if;
+ end loop;
+ end if;
+
+ -- Continue for any other node kind
+
+ else
+ return OK;
+ end if;
+ end Replace_Node;
+
+ begin
+ Replace_Type_Refs (N);
+ end Replace_Type_References_Generic;
+
+ -------------------------
+ -- Same_Representation --
+ -------------------------
+
+ function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
+ T1 : constant Entity_Id := Underlying_Type (Typ1);
+ T2 : constant Entity_Id := Underlying_Type (Typ2);
+
+ begin
+ -- A quick check, if base types are the same, then we definitely have
+ -- the same representation, because the subtype specific representation
+ -- attributes (Size and Alignment) do not affect representation from
+ -- the point of view of this test.
+
+ if Base_Type (T1) = Base_Type (T2) then
+ return True;
+
+ elsif Is_Private_Type (Base_Type (T2))
+ and then Base_Type (T1) = Full_View (Base_Type (T2))
+ then
+ return True;
+ end if;
+
+ -- Tagged types never have differing representations
+
+ if Is_Tagged_Type (T1) then
+ return True;
+ end if;
+
+ -- Representations are definitely different if conventions differ
+
+ if Convention (T1) /= Convention (T2) then
+ return False;
+ end if;
+
+ -- Representations are different if component alignments differ
+
+ if (Is_Record_Type (T1) or else Is_Array_Type (T1))
+ and then
+ (Is_Record_Type (T2) or else Is_Array_Type (T2))
+ and then Component_Alignment (T1) /= Component_Alignment (T2)
+ then
+ return False;
+ end if;
+
+ -- For arrays, the only real issue is component size. If we know the
+ -- component size for both arrays, and it is the same, then that's
+ -- good enough to know we don't have a change of representation.
+
+ if Is_Array_Type (T1) then
+ if Known_Component_Size (T1)
+ and then Known_Component_Size (T2)
+ and then Component_Size (T1) = Component_Size (T2)
+ then
+ return True;
+ end if;
+ end if;
+
+ -- Types definitely have same representation if neither has non-standard
+ -- representation since default representations are always consistent.
+ -- If only one has non-standard representation, and the other does not,
+ -- then we consider that they do not have the same representation. They
+ -- might, but there is no way of telling early enough.
+
+ if Has_Non_Standard_Rep (T1) then
+ if not Has_Non_Standard_Rep (T2) then
+ return False;
+ end if;
+ else
+ return not Has_Non_Standard_Rep (T2);
+ end if;
+
+ -- Here the two types both have non-standard representation, and we need
+ -- to determine if they have the same non-standard representation.
+
+ -- For arrays, we simply need to test if the component sizes are the
+ -- same. Pragma Pack is reflected in modified component sizes, so this
+ -- check also deals with pragma Pack.
+
+ if Is_Array_Type (T1) then
+ return Component_Size (T1) = Component_Size (T2);
+
+ -- Tagged types always have the same representation, because it is not
+ -- possible to specify different representations for common fields.
+
+ elsif Is_Tagged_Type (T1) then
+ return True;
+
+ -- Case of record types
+
+ elsif Is_Record_Type (T1) then
+
+ -- Packed status must conform
+
+ if Is_Packed (T1) /= Is_Packed (T2) then
+ return False;
+
+ -- Otherwise we must check components. Typ2 maybe a constrained
+ -- subtype with fewer components, so we compare the components
+ -- of the base types.
+
+ else
+ Record_Case : declare
+ CD1, CD2 : Entity_Id;
+
+ function Same_Rep return Boolean;
+ -- CD1 and CD2 are either components or discriminants. This
+ -- function tests whether the two have the same representation
+
+ --------------
+ -- Same_Rep --
+ --------------
+
+ function Same_Rep return Boolean is
+ begin
+ if No (Component_Clause (CD1)) then
+ return No (Component_Clause (CD2));
+
+ else
+ return
+ Present (Component_Clause (CD2))
+ and then
+ Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
+ and then
+ Esize (CD1) = Esize (CD2);
+ end if;
+ end Same_Rep;
+
+ -- Start of processing for Record_Case
+
+ begin
+ if Has_Discriminants (T1) then
+ CD1 := First_Discriminant (T1);
+ CD2 := First_Discriminant (T2);
+
+ -- The number of discriminants may be different if the
+ -- derived type has fewer (constrained by values). The
+ -- invisible discriminants retain the representation of
+ -- the original, so the discrepancy does not per se
+ -- indicate a different representation.
+
+ while Present (CD1)
+ and then Present (CD2)
+ loop
+ if not Same_Rep then
+ return False;
+ else
+ Next_Discriminant (CD1);
+ Next_Discriminant (CD2);
+ end if;
+ end loop;
+ end if;
+
+ CD1 := First_Component (Underlying_Type (Base_Type (T1)));
+ CD2 := First_Component (Underlying_Type (Base_Type (T2)));
+
+ while Present (CD1) loop
+ if not Same_Rep then
+ return False;
+ else
+ Next_Component (CD1);
+ Next_Component (CD2);
+ end if;
+ end loop;
+
+ return True;
+ end Record_Case;
+ end if;
+
+ -- For enumeration types, we must check each literal to see if the
+ -- representation is the same. Note that we do not permit enumeration
+ -- representation clauses for Character and Wide_Character, so these
+ -- cases were already dealt with.
+
+ elsif Is_Enumeration_Type (T1) then
+ Enumeration_Case : declare
+ L1, L2 : Entity_Id;
+
+ begin
+ L1 := First_Literal (T1);
+ L2 := First_Literal (T2);
+
+ while Present (L1) loop
+ if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
+ return False;
+ else
+ Next_Literal (L1);
+ Next_Literal (L2);
+ end if;
+ end loop;
+
+ return True;
+
+ end Enumeration_Case;
+
+ -- Any other types have the same representation for these purposes
+
+ else
+ return True;
+ end if;
+ end Same_Representation;
+
+ ----------------
+ -- Set_Biased --
+ ----------------
+
+ procedure Set_Biased
+ (E : Entity_Id;
+ N : Node_Id;
+ Msg : String;
+ Biased : Boolean := True)
+ is
+ begin
+ if Biased then
+ Set_Has_Biased_Representation (E);
+
+ if Warn_On_Biased_Representation then
+ Error_Msg_NE
+ ("?" & Msg & " forces biased representation for&", N, E);
+ end if;
+ end if;
+ end Set_Biased;
+
+ --------------------
+ -- Set_Enum_Esize --
+ --------------------
+
+ procedure Set_Enum_Esize (T : Entity_Id) is
+ Lo : Uint;
+ Hi : Uint;
+ Sz : Nat;
+
+ begin
+ Init_Alignment (T);
+
+ -- Find the minimum standard size (8,16,32,64) that fits
+
+ Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
+ Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
+
+ if Lo < 0 then
+ if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
+ Sz := Standard_Character_Size; -- May be > 8 on some targets
+
+ elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
+ Sz := 16;
+
+ elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
+ Sz := 32;
+
+ else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
+ Sz := 64;
+ end if;
+
+ else
+ if Hi < Uint_2**08 then
+ Sz := Standard_Character_Size; -- May be > 8 on some targets
+
+ elsif Hi < Uint_2**16 then
+ Sz := 16;
+
+ elsif Hi < Uint_2**32 then
+ Sz := 32;
+
+ else pragma Assert (Hi < Uint_2**63);
+ Sz := 64;
+ end if;
+ end if;
+
+ -- That minimum is the proper size unless we have a foreign convention
+ -- and the size required is 32 or less, in which case we bump the size
+ -- up to 32. This is required for C and C++ and seems reasonable for
+ -- all other foreign conventions.
+
+ if Has_Foreign_Convention (T)
+ and then Esize (T) < Standard_Integer_Size
+ then
+ Init_Esize (T, Standard_Integer_Size);
+ else
+ Init_Esize (T, Sz);
+ end if;
+ end Set_Enum_Esize;
+
+ ------------------------------
+ -- Validate_Address_Clauses --
+ ------------------------------
+
+ procedure Validate_Address_Clauses is
+ begin
+ for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
+ declare
+ ACCR : Address_Clause_Check_Record
+ renames Address_Clause_Checks.Table (J);
+
+ Expr : Node_Id;
+
+ X_Alignment : Uint;
+ Y_Alignment : Uint;
+
+ X_Size : Uint;
+ Y_Size : Uint;
+
+ begin
+ -- Skip processing of this entry if warning already posted
+
+ if not Address_Warning_Posted (ACCR.N) then
+
+ Expr := Original_Node (Expression (ACCR.N));
+
+ -- Get alignments
+
+ X_Alignment := Alignment (ACCR.X);
+ Y_Alignment := Alignment (ACCR.Y);
+
+ -- Similarly obtain sizes
+
+ X_Size := Esize (ACCR.X);
+ Y_Size := Esize (ACCR.Y);
+
+ -- Check for large object overlaying smaller one
+
+ if Y_Size > Uint_0
+ and then X_Size > Uint_0
+ and then X_Size > Y_Size
+ then
+ Error_Msg_NE
+ ("?& overlays smaller object", ACCR.N, ACCR.X);
+ Error_Msg_N
+ ("\?program execution may be erroneous", ACCR.N);
+ Error_Msg_Uint_1 := X_Size;
+ Error_Msg_NE
+ ("\?size of & is ^", ACCR.N, ACCR.X);
+ Error_Msg_Uint_1 := Y_Size;
+ Error_Msg_NE
+ ("\?size of & is ^", ACCR.N, ACCR.Y);
+
+ -- Check for inadequate alignment, both of the base object
+ -- and of the offset, if any.
+
+ -- Note: we do not check the alignment if we gave a size
+ -- warning, since it would likely be redundant.
+
+ elsif Y_Alignment /= Uint_0
+ and then (Y_Alignment < X_Alignment
+ or else (ACCR.Off
+ and then
+ Nkind (Expr) = N_Attribute_Reference
+ and then
+ Attribute_Name (Expr) = Name_Address
+ and then
+ Has_Compatible_Alignment
+ (ACCR.X, Prefix (Expr))
+ /= Known_Compatible))
+ then
+ Error_Msg_NE
+ ("?specified address for& may be inconsistent "
+ & "with alignment",
+ ACCR.N, ACCR.X);
+ Error_Msg_N
+ ("\?program execution may be erroneous (RM 13.3(27))",
+ ACCR.N);
+ Error_Msg_Uint_1 := X_Alignment;
+ Error_Msg_NE
+ ("\?alignment of & is ^",
+ ACCR.N, ACCR.X);
+ Error_Msg_Uint_1 := Y_Alignment;
+ Error_Msg_NE
+ ("\?alignment of & is ^",
+ ACCR.N, ACCR.Y);
+ if Y_Alignment >= X_Alignment then
+ Error_Msg_N
+ ("\?but offset is not multiple of alignment",
+ ACCR.N);
+ end if;
+ end if;
+ end if;
+ end;
+ end loop;
+ end Validate_Address_Clauses;
+
+ ---------------------------
+ -- Validate_Independence --
+ ---------------------------
+
+ procedure Validate_Independence is
+ SU : constant Uint := UI_From_Int (System_Storage_Unit);
+ N : Node_Id;
+ E : Entity_Id;
+ IC : Boolean;
+ Comp : Entity_Id;
+ Addr : Node_Id;
+ P : Node_Id;
+
+ procedure Check_Array_Type (Atyp : Entity_Id);
+ -- Checks if the array type Atyp has independent components, and
+ -- if not, outputs an appropriate set of error messages.
+
+ procedure No_Independence;
+ -- Output message that independence cannot be guaranteed
+
+ function OK_Component (C : Entity_Id) return Boolean;
+ -- Checks one component to see if it is independently accessible, and
+ -- if so yields True, otherwise yields False if independent access
+ -- cannot be guaranteed. This is a conservative routine, it only
+ -- returns True if it knows for sure, it returns False if it knows
+ -- there is a problem, or it cannot be sure there is no problem.
+
+ procedure Reason_Bad_Component (C : Entity_Id);
+ -- Outputs continuation message if a reason can be determined for
+ -- the component C being bad.
+
+ ----------------------
+ -- Check_Array_Type --
+ ----------------------
+
+ procedure Check_Array_Type (Atyp : Entity_Id) is
+ Ctyp : constant Entity_Id := Component_Type (Atyp);
+
+ begin
+ -- OK if no alignment clause, no pack, and no component size
+
+ if not Has_Component_Size_Clause (Atyp)
+ and then not Has_Alignment_Clause (Atyp)
+ and then not Is_Packed (Atyp)
+ then
+ return;
+ end if;
+
+ -- Check actual component size
+
+ if not Known_Component_Size (Atyp)
+ or else not (Addressable (Component_Size (Atyp))
+ and then Component_Size (Atyp) < 64)
+ or else Component_Size (Atyp) mod Esize (Ctyp) /= 0
+ then
+ No_Independence;
+
+ -- Bad component size, check reason
+
+ if Has_Component_Size_Clause (Atyp) then
+ P :=
+ Get_Attribute_Definition_Clause
+ (Atyp, Attribute_Component_Size);
+
+ if Present (P) then
+ Error_Msg_Sloc := Sloc (P);
+ Error_Msg_N ("\because of Component_Size clause#", N);
+ return;
+ end if;
+ end if;
+
+ if Is_Packed (Atyp) then
+ P := Get_Rep_Pragma (Atyp, Name_Pack);
+
+ if Present (P) then
+ Error_Msg_Sloc := Sloc (P);
+ Error_Msg_N ("\because of pragma Pack#", N);
+ return;
+ end if;
+ end if;
+
+ -- No reason found, just return
+
+ return;
+ end if;
+
+ -- Array type is OK independence-wise
+
+ return;
+ end Check_Array_Type;
+
+ ---------------------
+ -- No_Independence --
+ ---------------------
+
+ procedure No_Independence is
+ begin
+ if Pragma_Name (N) = Name_Independent then
+ Error_Msg_NE
+ ("independence cannot be guaranteed for&", N, E);
+ else
+ Error_Msg_NE
+ ("independent components cannot be guaranteed for&", N, E);
+ end if;
+ end No_Independence;
+
+ ------------------
+ -- OK_Component --
+ ------------------
+
+ function OK_Component (C : Entity_Id) return Boolean is
+ Rec : constant Entity_Id := Scope (C);
+ Ctyp : constant Entity_Id := Etype (C);
+
+ begin
+ -- OK if no component clause, no Pack, and no alignment clause
+
+ if No (Component_Clause (C))
+ and then not Is_Packed (Rec)
+ and then not Has_Alignment_Clause (Rec)
+ then
+ return True;
+ end if;
+
+ -- Here we look at the actual component layout. A component is
+ -- addressable if its size is a multiple of the Esize of the
+ -- component type, and its starting position in the record has
+ -- appropriate alignment, and the record itself has appropriate
+ -- alignment to guarantee the component alignment.
+
+ -- Make sure sizes are static, always assume the worst for any
+ -- cases where we cannot check static values.
+
+ if not (Known_Static_Esize (C)
+ and then Known_Static_Esize (Ctyp))
+ then
+ return False;
+ end if;
+
+ -- Size of component must be addressable or greater than 64 bits
+ -- and a multiple of bytes.
+
+ if not Addressable (Esize (C))
+ and then Esize (C) < Uint_64
+ then
+ return False;
+ end if;
+
+ -- Check size is proper multiple
+
+ if Esize (C) mod Esize (Ctyp) /= 0 then
+ return False;
+ end if;
+
+ -- Check alignment of component is OK
+
+ if not Known_Component_Bit_Offset (C)
+ or else Component_Bit_Offset (C) < Uint_0
+ or else Component_Bit_Offset (C) mod Esize (Ctyp) /= 0
+ then
+ return False;
+ end if;
+
+ -- Check alignment of record type is OK
+
+ if not Known_Alignment (Rec)
+ or else (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
+ then
+ return False;
+ end if;
+
+ -- All tests passed, component is addressable
+
+ return True;
+ end OK_Component;
+
+ --------------------------
+ -- Reason_Bad_Component --
+ --------------------------
+
+ procedure Reason_Bad_Component (C : Entity_Id) is
+ Rec : constant Entity_Id := Scope (C);
+ Ctyp : constant Entity_Id := Etype (C);
+
+ begin
+ -- If component clause present assume that's the problem
+
+ if Present (Component_Clause (C)) then
+ Error_Msg_Sloc := Sloc (Component_Clause (C));
+ Error_Msg_N ("\because of Component_Clause#", N);
+ return;
+ end if;
+
+ -- If pragma Pack clause present, assume that's the problem
+
+ if Is_Packed (Rec) then
+ P := Get_Rep_Pragma (Rec, Name_Pack);
+
+ if Present (P) then
+ Error_Msg_Sloc := Sloc (P);
+ Error_Msg_N ("\because of pragma Pack#", N);
+ return;
+ end if;
+ end if;
+
+ -- See if record has bad alignment clause
+
+ if Has_Alignment_Clause (Rec)
+ and then Known_Alignment (Rec)
+ and then (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
+ then
+ P := Get_Attribute_Definition_Clause (Rec, Attribute_Alignment);
+
+ if Present (P) then
+ Error_Msg_Sloc := Sloc (P);
+ Error_Msg_N ("\because of Alignment clause#", N);
+ end if;
+ end if;
+
+ -- Couldn't find a reason, so return without a message
+
+ return;
+ end Reason_Bad_Component;
+
+ -- Start of processing for Validate_Independence
+
+ begin
+ for J in Independence_Checks.First .. Independence_Checks.Last loop
+ N := Independence_Checks.Table (J).N;
+ E := Independence_Checks.Table (J).E;
+ IC := Pragma_Name (N) = Name_Independent_Components;
+
+ -- Deal with component case
+
+ if Ekind (E) = E_Discriminant or else Ekind (E) = E_Component then
+ if not OK_Component (E) then
+ No_Independence;
+ Reason_Bad_Component (E);
+ goto Continue;
+ end if;
+ end if;
+
+ -- Deal with record with Independent_Components
+
+ if IC and then Is_Record_Type (E) then
+ Comp := First_Component_Or_Discriminant (E);
+ while Present (Comp) loop
+ if not OK_Component (Comp) then
+ No_Independence;
+ Reason_Bad_Component (Comp);
+ goto Continue;
+ end if;
+
+ Next_Component_Or_Discriminant (Comp);
+ end loop;
+ end if;
+
+ -- Deal with address clause case
+
+ if Is_Object (E) then
+ Addr := Address_Clause (E);
+
+ if Present (Addr) then
+ No_Independence;
+ Error_Msg_Sloc := Sloc (Addr);
+ Error_Msg_N ("\because of Address clause#", N);
+ goto Continue;
+ end if;
+ end if;
+
+ -- Deal with independent components for array type
+
+ if IC and then Is_Array_Type (E) then
+ Check_Array_Type (E);
+ end if;
+
+ -- Deal with independent components for array object
+
+ if IC and then Is_Object (E) and then Is_Array_Type (Etype (E)) then
+ Check_Array_Type (Etype (E));
+ end if;
+
+ <<Continue>> null;
+ end loop;
+ end Validate_Independence;
+
+ -----------------------------------
+ -- Validate_Unchecked_Conversion --
+ -----------------------------------
+
+ procedure Validate_Unchecked_Conversion
+ (N : Node_Id;
+ Act_Unit : Entity_Id)
+ is
+ Source : Entity_Id;
+ Target : Entity_Id;
+ Vnode : Node_Id;
+
+ begin
+ -- Obtain source and target types. Note that we call Ancestor_Subtype
+ -- here because the processing for generic instantiation always makes
+ -- subtypes, and we want the original frozen actual types.
+
+ -- If we are dealing with private types, then do the check on their
+ -- fully declared counterparts if the full declarations have been
+ -- encountered (they don't have to be visible, but they must exist!)
+
+ Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
+
+ if Is_Private_Type (Source)
+ and then Present (Underlying_Type (Source))
+ then
+ Source := Underlying_Type (Source);
+ end if;
+
+ Target := Ancestor_Subtype (Etype (Act_Unit));
+
+ -- If either type is generic, the instantiation happens within a generic
+ -- unit, and there is nothing to check. The proper check
+ -- will happen when the enclosing generic is instantiated.
+
+ if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
+ return;
+ end if;
+
+ if Is_Private_Type (Target)
+ and then Present (Underlying_Type (Target))
+ then
+ Target := Underlying_Type (Target);
+ end if;
+
+ -- Source may be unconstrained array, but not target
+
+ if Is_Array_Type (Target)
+ and then not Is_Constrained (Target)
+ then
+ Error_Msg_N
+ ("unchecked conversion to unconstrained array not allowed", N);
+ return;
+ end if;
+
+ -- Warn if conversion between two different convention pointers
+
+ if Is_Access_Type (Target)
+ and then Is_Access_Type (Source)
+ and then Convention (Target) /= Convention (Source)
+ and then Warn_On_Unchecked_Conversion
+ then
+ -- Give warnings for subprogram pointers only on most targets. The
+ -- exception is VMS, where data pointers can have different lengths
+ -- depending on the pointer convention.
+
+ if Is_Access_Subprogram_Type (Target)
+ or else Is_Access_Subprogram_Type (Source)
+ or else OpenVMS_On_Target
+ then
+ Error_Msg_N
+ ("?conversion between pointers with different conventions!", N);
+ end if;
+ end if;
+
+ -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
+ -- warning when compiling GNAT-related sources.
+
+ if Warn_On_Unchecked_Conversion
+ and then not In_Predefined_Unit (N)
+ and then RTU_Loaded (Ada_Calendar)
+ and then
+ (Chars (Source) = Name_Time
+ or else
+ Chars (Target) = Name_Time)
+ then
+ -- If Ada.Calendar is loaded and the name of one of the operands is
+ -- Time, there is a good chance that this is Ada.Calendar.Time.
+
+ declare
+ Calendar_Time : constant Entity_Id :=
+ Full_View (RTE (RO_CA_Time));
+ begin
+ pragma Assert (Present (Calendar_Time));
+
+ if Source = Calendar_Time
+ or else Target = Calendar_Time
+ then
+ Error_Msg_N
+ ("?representation of 'Time values may change between " &
+ "'G'N'A'T versions", N);
+ end if;
+ end;
+ end if;
+
+ -- Make entry in unchecked conversion table for later processing by
+ -- Validate_Unchecked_Conversions, which will check sizes and alignments
+ -- (using values set by the back-end where possible). This is only done
+ -- if the appropriate warning is active.
+
+ if Warn_On_Unchecked_Conversion then
+ Unchecked_Conversions.Append
+ (New_Val => UC_Entry'
+ (Eloc => Sloc (N),
+ Source => Source,
+ Target => Target));
+
+ -- If both sizes are known statically now, then back end annotation
+ -- is not required to do a proper check but if either size is not
+ -- known statically, then we need the annotation.
+
+ if Known_Static_RM_Size (Source)
+ and then Known_Static_RM_Size (Target)
+ then
+ null;
+ else
+ Back_Annotate_Rep_Info := True;
+ end if;
+ end if;
+
+ -- If unchecked conversion to access type, and access type is declared
+ -- in the same unit as the unchecked conversion, then set the
+ -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
+ -- situation).
+
+ if Is_Access_Type (Target) and then
+ In_Same_Source_Unit (Target, N)
+ then
+ Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
+ end if;
+
+ -- Generate N_Validate_Unchecked_Conversion node for back end in
+ -- case the back end needs to perform special validation checks.
+
+ -- Shouldn't this be in Exp_Ch13, since the check only gets done
+ -- if we have full expansion and the back end is called ???
+
+ Vnode :=
+ Make_Validate_Unchecked_Conversion (Sloc (N));
+ Set_Source_Type (Vnode, Source);
+ Set_Target_Type (Vnode, Target);
+
+ -- If the unchecked conversion node is in a list, just insert before it.
+ -- If not we have some strange case, not worth bothering about.
+
+ if Is_List_Member (N) then
+ Insert_After (N, Vnode);
+ end if;
+ end Validate_Unchecked_Conversion;
+
+ ------------------------------------
+ -- Validate_Unchecked_Conversions --
+ ------------------------------------
+
+ procedure Validate_Unchecked_Conversions is
+ begin
+ for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
+ declare
+ T : UC_Entry renames Unchecked_Conversions.Table (N);
+
+ Eloc : constant Source_Ptr := T.Eloc;
+ Source : constant Entity_Id := T.Source;
+ Target : constant Entity_Id := T.Target;
+
+ Source_Siz : Uint;
+ Target_Siz : Uint;
+
+ begin
+ -- This validation check, which warns if we have unequal sizes for
+ -- unchecked conversion, and thus potentially implementation
+ -- dependent semantics, is one of the few occasions on which we
+ -- use the official RM size instead of Esize. See description in
+ -- Einfo "Handling of Type'Size Values" for details.
+
+ if Serious_Errors_Detected = 0
+ and then Known_Static_RM_Size (Source)
+ and then Known_Static_RM_Size (Target)
+
+ -- Don't do the check if warnings off for either type, note the
+ -- deliberate use of OR here instead of OR ELSE to get the flag
+ -- Warnings_Off_Used set for both types if appropriate.
+
+ and then not (Has_Warnings_Off (Source)
+ or
+ Has_Warnings_Off (Target))
+ then
+ Source_Siz := RM_Size (Source);
+ Target_Siz := RM_Size (Target);
+
+ if Source_Siz /= Target_Siz then
+ Error_Msg
+ ("?types for unchecked conversion have different sizes!",
+ Eloc);
+
+ if All_Errors_Mode then
+ Error_Msg_Name_1 := Chars (Source);
+ Error_Msg_Uint_1 := Source_Siz;
+ Error_Msg_Name_2 := Chars (Target);
+ Error_Msg_Uint_2 := Target_Siz;
+ Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
+
+ Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
+
+ if Is_Discrete_Type (Source)
+ and then Is_Discrete_Type (Target)
+ then
+ if Source_Siz > Target_Siz then
+ Error_Msg
+ ("\?^ high order bits of source will be ignored!",
+ Eloc);
+
+ elsif Is_Unsigned_Type (Source) then
+ Error_Msg
+ ("\?source will be extended with ^ high order " &
+ "zero bits?!", Eloc);
+
+ else
+ Error_Msg
+ ("\?source will be extended with ^ high order " &
+ "sign bits!",
+ Eloc);
+ end if;
+
+ elsif Source_Siz < Target_Siz then
+ if Is_Discrete_Type (Target) then
+ if Bytes_Big_Endian then
+ Error_Msg
+ ("\?target value will include ^ undefined " &
+ "low order bits!",
+ Eloc);
+ else
+ Error_Msg
+ ("\?target value will include ^ undefined " &
+ "high order bits!",
+ Eloc);
+ end if;
+
+ else
+ Error_Msg
+ ("\?^ trailing bits of target value will be " &
+ "undefined!", Eloc);
+ end if;
+
+ else pragma Assert (Source_Siz > Target_Siz);
+ Error_Msg
+ ("\?^ trailing bits of source will be ignored!",
+ Eloc);
+ end if;
+ end if;
+ end if;
+ end if;
+
+ -- If both types are access types, we need to check the alignment.
+ -- If the alignment of both is specified, we can do it here.
+
+ if Serious_Errors_Detected = 0
+ and then Ekind (Source) in Access_Kind
+ and then Ekind (Target) in Access_Kind
+ and then Target_Strict_Alignment
+ and then Present (Designated_Type (Source))
+ and then Present (Designated_Type (Target))
+ then
+ declare
+ D_Source : constant Entity_Id := Designated_Type (Source);
+ D_Target : constant Entity_Id := Designated_Type (Target);
+
+ begin
+ if Known_Alignment (D_Source)
+ and then Known_Alignment (D_Target)
+ then
+ declare
+ Source_Align : constant Uint := Alignment (D_Source);
+ Target_Align : constant Uint := Alignment (D_Target);
+
+ begin
+ if Source_Align < Target_Align
+ and then not Is_Tagged_Type (D_Source)
+
+ -- Suppress warning if warnings suppressed on either
+ -- type or either designated type. Note the use of
+ -- OR here instead of OR ELSE. That is intentional,
+ -- we would like to set flag Warnings_Off_Used in
+ -- all types for which warnings are suppressed.
+
+ and then not (Has_Warnings_Off (D_Source)
+ or
+ Has_Warnings_Off (D_Target)
+ or
+ Has_Warnings_Off (Source)
+ or
+ Has_Warnings_Off (Target))
+ then
+ Error_Msg_Uint_1 := Target_Align;
+ Error_Msg_Uint_2 := Source_Align;
+ Error_Msg_Node_1 := D_Target;
+ Error_Msg_Node_2 := D_Source;
+ Error_Msg
+ ("?alignment of & (^) is stricter than " &
+ "alignment of & (^)!", Eloc);
+ Error_Msg
+ ("\?resulting access value may have invalid " &
+ "alignment!", Eloc);
+ end if;
+ end;
+ end if;
+ end;
+ end if;
+ end;
+ end loop;
+ end Validate_Unchecked_Conversions;
+
+end Sem_Ch13;
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-26 07:52:34 +0000