c-common.c (decl_with_nonnull_addr_p): New function.

c-common.c (decl_with_nonnull_addr_p): New function.

./:	* c-common.c (decl_with_nonnull_addr_p): New function.
	(c_common_truthvalue_conversion): Call it.
	* c-typeck.c (build_binary_op): Likewise.
	* c-common.h (decl_with_nonnull_addr_p): Declare.
cp/:
	* typeck.c (build_binary_op): Warn about comparing a non-weak
	address to NULL.
testsuite/:
	* gcc.dg/Walways-true-1.c: New test.
	* gcc.dg/Walways-true-2.c: New test.
	* g++.dg/warn/Walways-true-1.C: New test.
	* g++.dg/warn/Walways-true-2.C: New test.

From-SVN: r120493