re PR tree-optimization/43270 (array-bounds false negative)

2010-04-07  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/43270
	* tree-vrp.c (check_array_ref): Fix flexible array member
	detection.
	* tree-ssa-sccvn.h (fully_constant_vn_reference_p): Declare.
	* tree-ssa-pre.c (phi_translate_1): Adjust.
	(fully_constant_expression): Split out vn_reference handling to ...
	* tree-ssa-sccvn.c (fully_constant_vn_reference_p): ... here.
	Fold reads from constant strings.
	(vn_reference_lookup): Handle fully constant references.
	(vn_reference_lookup_pieces): Likewise.
	* Makefile.in (expmed.o-warn): Add -Wno-error.

	* g++.dg/warn/Warray-bounds-4.C: New testcase.
	* gcc.dg/Warray-bounds-7.c: Likewise.

From-SVN: r158058