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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/java/except.c
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Diffstat (limited to 'gcc/java/except.c')
-rw-r--r--gcc/java/except.c611
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diff --git a/gcc/java/except.c b/gcc/java/except.c
new file mode 100644
index 000000000..1705106c4
--- /dev/null
+++ b/gcc/java/except.c
@@ -0,0 +1,611 @@
+/* Handle exceptions for GNU compiler for the Java(TM) language.
+ Copyright (C) 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005,
+ 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>.
+
+Java and all Java-based marks are trademarks or registered trademarks
+of Sun Microsystems, Inc. in the United States and other countries.
+The Free Software Foundation is independent of Sun Microsystems, Inc. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "java-tree.h"
+#include "javaop.h"
+#include "java-opcodes.h"
+#include "jcf.h"
+#include "java-except.h"
+#include "diagnostic-core.h"
+#include "toplev.h"
+#include "tree-iterator.h"
+
+
+static void expand_start_java_handler (struct eh_range *);
+static struct eh_range *find_handler_in_range (int, struct eh_range *,
+ struct eh_range *);
+static void check_start_handlers (struct eh_range *, int);
+static void free_eh_ranges (struct eh_range *range);
+
+struct eh_range *current_method_handlers;
+
+struct eh_range *current_try_block = NULL;
+
+/* These variables are used to speed up find_handler. */
+
+static int cache_range_start, cache_range_end;
+static struct eh_range *cache_range;
+static struct eh_range *cache_next_child;
+
+/* A dummy range that represents the entire method. */
+
+struct eh_range whole_range;
+
+/* Check the invariants of the structure we're using to contain
+ exception regions. Either returns true or fails an assertion
+ check. */
+
+bool
+sanity_check_exception_range (struct eh_range *range)
+{
+ struct eh_range *ptr = range->first_child;
+ for (; ptr; ptr = ptr->next_sibling)
+ {
+ gcc_assert (ptr->outer == range
+ && ptr->end_pc > ptr->start_pc);
+ if (ptr->next_sibling)
+ gcc_assert (ptr->next_sibling->start_pc >= ptr->end_pc);
+ gcc_assert (ptr->start_pc >= ptr->outer->start_pc
+ && ptr->end_pc <= ptr->outer->end_pc);
+ (void) sanity_check_exception_range (ptr);
+ }
+ return true;
+}
+
+#if defined(DEBUG_JAVA_BINDING_LEVELS)
+extern int is_class_level;
+extern int current_pc;
+extern int binding_depth;
+extern void indent (void);
+static void
+print_ranges (struct eh_range *range)
+{
+ if (! range)
+ return;
+
+ struct eh_range *child = range->first_child;
+
+ indent ();
+ fprintf (stderr, "handler pc %d --> %d ", range->start_pc, range->end_pc);
+
+ tree handler = range->handlers;
+ for ( ; handler != NULL_TREE; handler = TREE_CHAIN (handler))
+ {
+ tree type = TREE_PURPOSE (handler);
+ if (type == NULL)
+ type = throwable_type_node;
+ fprintf (stderr, " type=%s ", IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))));
+ }
+ fprintf (stderr, "\n");
+
+ int saved = binding_depth;
+ binding_depth++;
+ print_ranges (child);
+ binding_depth = saved;
+
+ print_ranges (range->next_sibling);
+}
+#endif
+
+/* Search for the most specific eh_range containing PC.
+ Assume PC is within RANGE.
+ CHILD is a list of children of RANGE such that any
+ previous children have end_pc values that are too low. */
+
+static struct eh_range *
+find_handler_in_range (int pc, struct eh_range *range, struct eh_range *child)
+{
+ for (; child != NULL; child = child->next_sibling)
+ {
+ if (pc < child->start_pc)
+ break;
+ if (pc < child->end_pc)
+ return find_handler_in_range (pc, child, child->first_child);
+ }
+ cache_range = range;
+ cache_range_start = pc;
+ cache_next_child = child;
+ cache_range_end = child == NULL ? range->end_pc : child->start_pc;
+ return range;
+}
+
+/* Find the inner-most handler that contains PC. */
+
+struct eh_range *
+find_handler (int pc)
+{
+ struct eh_range *h;
+ if (pc >= cache_range_start)
+ {
+ h = cache_range;
+ if (pc < cache_range_end)
+ return h;
+ while (pc >= h->end_pc)
+ {
+ cache_next_child = h->next_sibling;
+ h = h->outer;
+ }
+ }
+ else
+ {
+ h = &whole_range;
+ cache_next_child = h->first_child;
+ }
+ return find_handler_in_range (pc, h, cache_next_child);
+}
+
+static void
+free_eh_ranges (struct eh_range *range)
+{
+ while (range)
+ {
+ struct eh_range *next = range->next_sibling;
+ free_eh_ranges (range->first_child);
+ if (range != &whole_range)
+ free (range);
+ range = next;
+ }
+}
+
+/* Called to re-initialize the exception machinery for a new method. */
+
+void
+method_init_exceptions (void)
+{
+ free_eh_ranges (&whole_range);
+ whole_range.start_pc = 0;
+ whole_range.end_pc = DECL_CODE_LENGTH (current_function_decl) + 1;
+ whole_range.outer = NULL;
+ whole_range.first_child = NULL;
+ whole_range.next_sibling = NULL;
+ cache_range_start = 0xFFFFFF;
+}
+
+/* Split an exception range into two at PC. The sub-ranges that
+ belong to the range are split and distributed between the two new
+ ranges. */
+
+static void
+split_range (struct eh_range *range, int pc)
+{
+ struct eh_range *ptr;
+ struct eh_range **first_child, **second_child;
+ struct eh_range *h;
+
+ /* First, split all the sub-ranges. */
+ for (ptr = range->first_child; ptr; ptr = ptr->next_sibling)
+ {
+ if (pc > ptr->start_pc
+ && pc < ptr->end_pc)
+ {
+ split_range (ptr, pc);
+ }
+ }
+
+ /* Create a new range. */
+ h = XNEW (struct eh_range);
+
+ h->start_pc = pc;
+ h->end_pc = range->end_pc;
+ h->next_sibling = range->next_sibling;
+ range->next_sibling = h;
+ range->end_pc = pc;
+ h->handlers = build_tree_list (TREE_PURPOSE (range->handlers),
+ TREE_VALUE (range->handlers));
+ h->next_sibling = NULL;
+ h->expanded = 0;
+ h->stmt = NULL;
+ h->outer = range->outer;
+ h->first_child = NULL;
+
+ ptr = range->first_child;
+ first_child = &range->first_child;
+ second_child = &h->first_child;
+
+ /* Distribute the sub-ranges between the two new ranges. */
+ for (ptr = range->first_child; ptr; ptr = ptr->next_sibling)
+ {
+ if (ptr->start_pc < pc)
+ {
+ *first_child = ptr;
+ ptr->outer = range;
+ first_child = &ptr->next_sibling;
+ }
+ else
+ {
+ *second_child = ptr;
+ ptr->outer = h;
+ second_child = &ptr->next_sibling;
+ }
+ }
+ *first_child = NULL;
+ *second_child = NULL;
+}
+
+
+/* Add an exception range.
+
+ There are some missed optimization opportunities here. For
+ example, some bytecode obfuscators generate seemingly
+ nonoverlapping exception ranges which, when coalesced, do in fact
+ nest correctly. We could merge these, but we'd have to fix up all
+ the enclosed regions first and perhaps create a new range anyway if
+ it overlapped existing ranges.
+
+ Also, we don't attempt to detect the case where two previously
+ added disjoint ranges could be coalesced by a new range. */
+
+void
+add_handler (int start_pc, int end_pc, tree handler, tree type)
+{
+ struct eh_range *ptr, *h;
+ struct eh_range **first_child, **prev;
+
+ /* First, split all the existing ranges that we need to enclose. */
+ for (ptr = whole_range.first_child; ptr; ptr = ptr->next_sibling)
+ {
+ if (start_pc > ptr->start_pc
+ && start_pc < ptr->end_pc)
+ {
+ split_range (ptr, start_pc);
+ }
+
+ if (end_pc > ptr->start_pc
+ && end_pc < ptr->end_pc)
+ {
+ split_range (ptr, end_pc);
+ }
+
+ if (ptr->start_pc >= end_pc)
+ break;
+ }
+
+ /* Create the new range. */
+ h = XNEW (struct eh_range);
+ first_child = &h->first_child;
+
+ h->start_pc = start_pc;
+ h->end_pc = end_pc;
+ h->first_child = NULL;
+ h->outer = NULL_EH_RANGE;
+ h->handlers = build_tree_list (type, handler);
+ h->next_sibling = NULL;
+ h->expanded = 0;
+ h->stmt = NULL;
+
+ /* Find every range at the top level that will be a sub-range of the
+ range we're inserting and make it so. */
+ {
+ struct eh_range **prev = &whole_range.first_child;
+ for (ptr = *prev; ptr;)
+ {
+ struct eh_range *next = ptr->next_sibling;
+
+ if (ptr->start_pc >= end_pc)
+ break;
+
+ if (ptr->start_pc < start_pc)
+ {
+ prev = &ptr->next_sibling;
+ }
+ else if (ptr->start_pc >= start_pc
+ && ptr->start_pc < end_pc)
+ {
+ *prev = next;
+ *first_child = ptr;
+ first_child = &ptr->next_sibling;
+ ptr->outer = h;
+ ptr->next_sibling = NULL;
+ }
+
+ ptr = next;
+ }
+ }
+
+ /* Find the right place to insert the new range. */
+ prev = &whole_range.first_child;
+ for (ptr = *prev; ptr; prev = &ptr->next_sibling, ptr = ptr->next_sibling)
+ {
+ gcc_assert (ptr->outer == NULL_EH_RANGE);
+ if (ptr->start_pc >= start_pc)
+ break;
+ }
+
+ /* And insert it there. */
+ *prev = h;
+ if (ptr)
+ {
+ h->next_sibling = ptr;
+ h->outer = ptr->outer;
+ }
+}
+
+
+/* if there are any handlers for this range, issue start of region */
+static void
+expand_start_java_handler (struct eh_range *range)
+{
+#if defined(DEBUG_JAVA_BINDING_LEVELS)
+ indent ();
+ fprintf (stderr, "expand start handler pc %d --> %d\n",
+ current_pc, range->end_pc);
+#endif /* defined(DEBUG_JAVA_BINDING_LEVELS) */
+ pushlevel (0);
+ register_exception_range (range, range->start_pc, range->end_pc);
+ range->expanded = 1;
+}
+
+tree
+prepare_eh_table_type (tree type)
+{
+ tree exp;
+ tree *slot;
+ const char *name;
+ char *buf;
+ tree decl;
+ tree utf8_ref;
+
+ /* The "type" (match_info) in a (Java) exception table is a pointer to:
+ * a) NULL - meaning match any type in a try-finally.
+ * b) a pointer to a pointer to a class.
+ * c) a pointer to a pointer to a utf8_ref. The pointer is
+ * rewritten to point to the appropriate class. */
+
+ if (type == NULL_TREE)
+ return NULL_TREE;
+
+ if (TYPE_TO_RUNTIME_MAP (output_class) == NULL)
+ TYPE_TO_RUNTIME_MAP (output_class) = java_treetreehash_create (10);
+
+ slot = java_treetreehash_new (TYPE_TO_RUNTIME_MAP (output_class), type);
+ if (*slot != NULL)
+ return TREE_VALUE (*slot);
+
+ if (is_compiled_class (type) && !flag_indirect_dispatch)
+ {
+ name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type)));
+ buf = (char *) alloca (strlen (name) + 5);
+ sprintf (buf, "%s_ref", name);
+ decl = build_decl (input_location,
+ VAR_DECL, get_identifier (buf), ptr_type_node);
+ TREE_STATIC (decl) = 1;
+ DECL_ARTIFICIAL (decl) = 1;
+ DECL_IGNORED_P (decl) = 1;
+ TREE_READONLY (decl) = 1;
+ TREE_THIS_VOLATILE (decl) = 0;
+ DECL_INITIAL (decl) = build_class_ref (type);
+ layout_decl (decl, 0);
+ pushdecl (decl);
+ exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (decl)), decl);
+ }
+ else
+ {
+ utf8_ref = build_utf8_ref (DECL_NAME (TYPE_NAME (type)));
+ name = IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (utf8_ref, 0)));
+ buf = (char *) alloca (strlen (name) + 5);
+ sprintf (buf, "%s_ref", name);
+ decl = build_decl (input_location,
+ VAR_DECL, get_identifier (buf), utf8const_ptr_type);
+ TREE_STATIC (decl) = 1;
+ DECL_ARTIFICIAL (decl) = 1;
+ DECL_IGNORED_P (decl) = 1;
+ TREE_READONLY (decl) = 1;
+ TREE_THIS_VOLATILE (decl) = 0;
+ layout_decl (decl, 0);
+ pushdecl (decl);
+ exp = build1 (ADDR_EXPR, build_pointer_type (utf8const_ptr_type), decl);
+ CONSTRUCTOR_APPEND_ELT (TYPE_CATCH_CLASSES (output_class),
+ NULL_TREE,
+ make_catch_class_record (exp, utf8_ref));
+ }
+
+ exp = convert (ptr_type_node, exp);
+
+ *slot = tree_cons (type, exp, NULL_TREE);
+
+ return exp;
+}
+
+static int
+expand_catch_class (void **entry, void *x ATTRIBUTE_UNUSED)
+{
+ struct treetreehash_entry *ite = (struct treetreehash_entry *) *entry;
+ tree addr = TREE_VALUE ((tree)ite->value);
+ tree decl;
+ STRIP_NOPS (addr);
+ decl = TREE_OPERAND (addr, 0);
+ rest_of_decl_compilation (decl, global_bindings_p (), 0);
+ return true;
+}
+
+/* For every class in the TYPE_TO_RUNTIME_MAP, expand the
+ corresponding object that is used by the runtime type matcher. */
+
+void
+java_expand_catch_classes (tree this_class)
+{
+ if (TYPE_TO_RUNTIME_MAP (this_class))
+ htab_traverse
+ (TYPE_TO_RUNTIME_MAP (this_class),
+ expand_catch_class, NULL);
+}
+
+/* Build and push the variable that will hold the exception object
+ within this function. */
+
+static tree
+build_exception_object_var (void)
+{
+ tree decl = DECL_FUNCTION_EXC_OBJ (current_function_decl);
+ if (decl == NULL)
+ {
+ decl = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
+ VAR_DECL, get_identifier ("#exc_obj"), ptr_type_node);
+ DECL_IGNORED_P (decl) = 1;
+ DECL_ARTIFICIAL (decl) = 1;
+
+ DECL_FUNCTION_EXC_OBJ (current_function_decl) = decl;
+ pushdecl_function_level (decl);
+ }
+ return decl;
+}
+
+/* Build a reference to the jthrowable object being carried in the
+ exception header. */
+
+tree
+build_exception_object_ref (tree type)
+{
+ tree obj;
+
+ /* Java only passes object via pointer and doesn't require adjusting.
+ The java object is immediately before the generic exception header. */
+ obj = build_exception_object_var ();
+ obj = fold_convert (build_pointer_type (type), obj);
+ obj = build2 (POINTER_PLUS_EXPR, TREE_TYPE (obj), obj,
+ fold_build1 (NEGATE_EXPR, sizetype,
+ TYPE_SIZE_UNIT (TREE_TYPE (obj))));
+ obj = build1 (INDIRECT_REF, type, obj);
+
+ return obj;
+}
+
+/* If there are any handlers for this range, issue end of range,
+ and then all handler blocks */
+void
+expand_end_java_handler (struct eh_range *range)
+{
+ tree handler = range->handlers;
+ if (handler)
+ {
+ tree exc_obj = build_exception_object_var ();
+ tree catches = make_node (STATEMENT_LIST);
+ tree_stmt_iterator catches_i = tsi_last (catches);
+ tree *body;
+
+ for (; handler; handler = TREE_CHAIN (handler))
+ {
+ tree type, eh_type, x;
+ tree stmts = make_node (STATEMENT_LIST);
+ tree_stmt_iterator stmts_i = tsi_last (stmts);
+
+ type = TREE_PURPOSE (handler);
+ if (type == NULL)
+ type = throwable_type_node;
+ eh_type = prepare_eh_table_type (type);
+
+ x = build_call_expr (built_in_decls[BUILT_IN_EH_POINTER],
+ 1, integer_zero_node);
+ x = build2 (MODIFY_EXPR, void_type_node, exc_obj, x);
+ tsi_link_after (&stmts_i, x, TSI_CONTINUE_LINKING);
+
+ x = build1 (GOTO_EXPR, void_type_node, TREE_VALUE (handler));
+ tsi_link_after (&stmts_i, x, TSI_CONTINUE_LINKING);
+
+ x = build2 (CATCH_EXPR, void_type_node, eh_type, stmts);
+ tsi_link_after (&catches_i, x, TSI_CONTINUE_LINKING);
+
+ /* Throwable can match anything in Java, and therefore
+ any subsequent handlers are unreachable. */
+ /* ??? If we're assured of no foreign language exceptions,
+ we'd be better off using NULL as the exception type
+ for the catch. */
+ if (type == throwable_type_node)
+ break;
+ }
+
+ body = get_stmts ();
+ *body = build2 (TRY_CATCH_EXPR, void_type_node, *body, catches);
+ }
+
+#if defined(DEBUG_JAVA_BINDING_LEVELS)
+ indent ();
+ fprintf (stderr, "expand end handler pc %d <-- %d\n",
+ current_pc, range->start_pc);
+#endif /* defined(DEBUG_JAVA_BINDING_LEVELS) */
+}
+
+/* Recursive helper routine for maybe_start_handlers. */
+
+static void
+check_start_handlers (struct eh_range *range, int pc)
+{
+ if (range != NULL_EH_RANGE && range->start_pc == pc)
+ {
+ check_start_handlers (range->outer, pc);
+ if (!range->expanded)
+ expand_start_java_handler (range);
+ }
+}
+
+
+/* Routine to see if exception handling is turned on.
+ DO_WARN is nonzero if we want to inform the user that exception
+ handling is turned off.
+
+ This is used to ensure that -fexceptions has been specified if the
+ compiler tries to use any exception-specific functions. */
+
+static inline int
+doing_eh (void)
+{
+ if (! flag_exceptions)
+ {
+ static int warned = 0;
+ if (! warned)
+ {
+ error ("exception handling disabled, use -fexceptions to enable");
+ warned = 1;
+ }
+ return 0;
+ }
+ return 1;
+}
+
+static struct eh_range *current_range;
+
+/* Emit any start-of-try-range starting at start_pc and ending after
+ end_pc. */
+
+void
+maybe_start_try (int start_pc, int end_pc)
+{
+ struct eh_range *range;
+ if (! doing_eh ())
+ return;
+
+ range = find_handler (start_pc);
+ while (range != NULL_EH_RANGE && range->start_pc == start_pc
+ && range->end_pc < end_pc)
+ range = range->outer;
+
+ current_range = range;
+ check_start_handlers (range, start_pc);
+}
+