gcc/ChangeLog:

2015-08-05  Manuel López-Ibáñez  <manu@gcc.gnu.org>
	    Jeff Law  <law@redhat.com>

	PR c/16351
	* doc/invoke.texi (Wnull-dereference): New.
	* tree-vrp.c (infer_value_range): Update call to infer_nonnull_range.
	* gimple-ssa-isolate-paths.c (find_implicit_erroneous_behaviour):
	Warn for potential NULL dereferences.
	(find_explicit_erroneous_behaviour): Warn for NULL dereferences.
	* ubsan.c (instrument_nonnull_arg): Call
	infer_nonnull_range_by_attribute.
	(instrument_nonnull_return): Likewise.
	* common.opt (Wnull-dereference); New.
	* gimple.c (infer_nonnull_range): Remove bool arguments.
	(infer_nonnull_range_by_dereference): New.
	(infer_nonnull_range_by_attribute): New.
	* gimple.h: Update declarations.

gcc/testsuite/ChangeLog:

2015-08-05  Manuel López-Ibáñez  <manu@gcc.gnu.org>
	    Jeff Law  <law@redhat.com>

	PR c/16351
	* gcc.dg/tree-ssa/isolate-2.c: Close comment.
	* gcc.dg/tree-ssa/isolate-4.c: Likewise.
	* gcc.dg/tree-ssa/wnull-dereference.c: New test.
	* gcc.dg/tree-ssa/isolate-1.c: Test warnings with -Wnull-dereference.
	* gcc.dg/tree-ssa/isolate-3.c: Likewise.
	* gcc.dg/tree-ssa/isolate-5.c: Likewise.



Co-Authored-By: Jeff Law <law@redhat.com>

From-SVN: r226640