PR c/78673 - sprintf missing attribute nonnull on destination argument

PR c/78673 - sprintf missing attribute nonnull on destination argument
PR c/17308 - nonnull attribute not as useful as it could be

gcc/ChangeLog:

	PR c/17308
	* builtin-attrs.def (ATTR_NONNULL_1_1, ATTR_NONNULL_1_2): Defined.
	(ATTR_NONNULL_1_3, ATTR_NONNULL_1_4, ATTR_NONNULL_1_5): Same.
	(ATTR_NOTHROW_NONNULL_1_1, ATTR_NOTHROW_NONNULL_1_2): Same.
	(ATTR_NOTHROW_NONNULL_1_3, ATTR_NOTHROW_NONNULL_1_4): Same.
	(ATTR_NOTHROW_NONNULL_1_5): Same.
	(ATTR_NONNULL_1_FORMAT_PRINTF_1_2): Same.
	(ATTR_NONNULL_1_FORMAT_PRINTF_2_0): Same.
	(ATTR_NONNULL_1_FORMAT_PRINTF_2_3): Same.
	(ATTR_NONNULL_1_FORMAT_PRINTF_3_0): Same.
	(ATTR_NONNULL_1_FORMAT_PRINTF_3_4): Same.
	(ATTR_NONNULL_1_FORMAT_PRINTF_4_0): Same.
	(ATTR_NONNULL_1_FORMAT_PRINTF_4_5): Same.
	* builtins.c (validate_arg): Add argument.  Treat null pointers
	passed to nonnull arguments as invalid.
	(validate_arglist): Same.
	* builtins.def (fprintf, fprintf_unlocked): Add nonnull attribute.
	(printf, printf_unlocked, sprintf. vfprintf, vsprintf): Same.
	(__sprintf_chk, __vsprintf_chk, __fprintf_chk, __vfprintf_chk): Same.
	* calls.c (get_nonnull_ags, maybe_warn_null_arg): New functions.
	(initialize_argument_information): Diagnose null pointers passed to
	arguments declared nonnull.
	* calls.h (get_nonnull_args): Declared.

gcc/c-family/ChangeLog:

	PR c/17308
	* c-common.c (check_nonnull_arg): Disable when optimization
	is enabled.

gcc/testsuite/ChangeLog:

	PR c/17308
	* gcc.dg/builtins-nonnull.c: New test.
	* gcc.dg/nonnull-4.c: New test.

From-SVN: r243661