re PR c/12913 (Jumps into variable length array scope not rejected)

	PR c/12913
	* c-tree.h (struct c_label_list): Update comment.
	(struct c_label_context): Rename to struct c_label_context_se.
	(label_context_stack): Rename to label_context_stack_se.
	(C_DECL_UNJUMPABLE_VM, C_DECL_UNDEFINABLE_VM, struct
	c_label_context_vm, label_context_stack_vm, c_begin_vm_scope,
	c_end_vm_scope): New.
	(C_DECL_DECLARED_BUILTIN, C_DECL_USED): Use FUNCTION_DECL_CHECK.
	* c-decl.c (pop_scope): Call c_end_vm_scope.
	(pushdecl): Call c_begin_vm_scope for variably modified
	declarations.
	(define_label): Check for jumping into scope of identifier with
	variably modified type.  Push label on stack for those defined at
	current context of identifiers with variably modified type.
	(start_function): Create stack level for context of identifiers
	with variably modified type.
	(finish_function): Pop stack level for context of identifiers with
	variably modified type.
	* c-typeck.c (label_context_stack): Rename to
	label_context_stack_se.
	(label_context_stack_vm, c_begin_vm_scope, c_end_vm_scope): New.
	(c_finish_goto_label): Check for jumping into scope of identifier
	with variably modified type.  Push label on stack for those jumped
	to from current context of identifiers with variably modified
	type.
	(struct c_switch): Add blocked_vm.
	(c_start_case): Initialize blocked_vm.
	(do_case): Check blocked_vm.
	(c_finish_case): Add comment.
	(c_begin_stmt_expr, c_finish_stmt_expr): Update for renamed
	variable label_context_stack.

objc:
	* objc-act.c (objc_start_function): Create stack level for context
	of identifiers with variably modified type.

testsuite:
	* gcc.dg/c99-vla-jump-1.c, gcc.dg/c99-vla-jump-2.c,
	gcc.dg/c99-vla-jump-3.c, gcc.dg/c99-vla-jump-4.c,
	gcc.dg/c99-vla-jump-5.c: New tests.

From-SVN: r98464

1 files changed, 13 insertions, 6 deletions

diff --git a/gcc/objc/objc-act.c b/gcc/objc/objc-act.c
index 986fb9f..62d5c84 100644
--- a/gcc/objc/objc-act.c
+++ b/gcc/objc/objc-act.c
@@ -7666,12 +7666,19 @@ objc_start_function (tree name, tree type, tree attrs,
   cplus_decl_attributes (&fndecl, attrs, 0);
   start_preparsed_function (fndecl, attrs, /*flags=*/SF_DEFAULT);
 #else
-  struct c_label_context *nstack;
-  nstack = XOBNEW (&parser_obstack, struct c_label_context);
-  nstack->labels_def = NULL;
-  nstack->labels_used = NULL;
-  nstack->next = label_context_stack;
-  label_context_stack = nstack;
+  struct c_label_context_se *nstack_se;
+  struct c_label_context_vm *nstack_vm;
+  nstack_se = XOBNEW (&parser_obstack, struct c_label_context_se);
+  nstack_se->labels_def = NULL;
+  nstack_se->labels_used = NULL;
+  nstack_se->next = label_context_stack_se;
+  label_context_stack_se = nstack_se;
+  nstack_vm = XOBNEW (&parser_obstack, struct c_label_context_vm);
+  nstack_vm->labels_def = NULL;
+  nstack_vm->labels_used = NULL;
+  nstack_vm->scope = 0;
+  nstack_vm->next = label_context_stack_vm;
+  label_context_stack_vm = nstack_vm;
   decl_attributes (&fndecl, attrs, 0);
   announce_function (fndecl);
   DECL_INITIAL (fndecl) = error_mark_node;