Patch for bug 12913

["Joseph S. Myers" <joseph at codesourcery dot com>]

This patch fixes bug 12913, that jumps into scope of identifiers with
variably modified type should, as per C99, be rejected.  Bootstrapped
with no regressions on x86_64-unknown-linux-gnu.  Applied to mainline.
Some cases were rejected by 3.4 and so are regressions in 4.0, so I
propose to apply this patch for 4.0.1.

The corresponding C++ bug is bug 21113.  As with bugs 772/17913, much
the same approach should be applicable to fixing this problem for C++.

The patch is gzipped because it includes nearly 500kbytes of
testcases.  The script for generating most of these is also attached.

-- 
Joseph S. Myers               http://www.srcf.ucam.org/~jsm28/gcc/
    jsm@polyomino.org.uk (personal mail)
    joseph@codesourcery.com (CodeSourcery mail)
    jsm28@gcc.gnu.org (Bugzilla assignments and CCs)

2005-04-20  Joseph S. Myers  <joseph@codesourcery.com>

	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:
2005-04-20  Joseph S. Myers  <joseph@codesourcery.com>

	PR c/12913
	* objc-act.c (objc_start_function): Create stack level for context
	of identifiers with variably modified type.

testsuite:
2005-04-20  Joseph S. Myers  <joseph@codesourcery.com>

	PR c/12913
	* 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.

Attachment: 12913-patch.gz
Description: Binary data

Attachment: gen12913
Description: Text document