PR c/77531 - __attribute__((alloc_size(1,2))) could also warn on multiplication overflow
PR c/78284 - warn on malloc with very large arguments

gcc/c-family/ChangeLog:

	PR c/78284
	* c.opt (-Walloc-zero, -Walloc-size-larger-than): New options.

gcc/ChangeLog:

	PR c/78284
	* builtin-attrs.def (ATTR_ALLOC_SIZE, ATTR_RETURNS_NONNULL): New
	identifier tree nodes.
	(ATTR_ALLOCA_SIZE_1_NOTHROW_LEAF_LIST): New attribute list.
	(ATTR_MALLOC_SIZE_1_NOTHROW_LIST): Same.
	(ATTR_MALLOC_SIZE_1_NOTHROW_LEAF_LIST): Same.
	(ATTR_MALLOC_SIZE_1_2_NOTHROW_LEAF_LIST): Same.
	(ATTR_ALLOC_SIZE_2_NOTHROW_LEAF_LIST): Same.
	* builtins.c (expand_builtin_alloca): Call
	maybe_warn_alloc_args_overflow.
	* builtins.def (aligned_alloc, calloc, malloc, realloc):
	Add attribute alloc_size.
	(alloca): Add attribute alloc_size and returns_nonnull.
	* calls.h (maybe_warn_alloc_args_overflow): Declare.
	* calls.c (alloc_max_size, operand_signed_p): New functions.
	(maybe_warn_alloc_args_overflow): Define.
	(initialize_argument_information): Diagnose overflow in functions
	declared with attaribute alloc_size.
	* doc/invoke.texi (Warning Options): Document -Walloc-zero and
	-Walloc-size-larger-than.

gcc/testsuite/ChangeLog:

	PR c/78284
	* gcc.dg/attr-alloc_size-3.c: New test.
	* gcc.dg/attr-alloc_size-4.c: New test.
	* gcc.dg/attr-alloc_size-5.c: New test.
	* gcc.dg/attr-alloc_size-6.c: New test.
	* gcc.dg/attr-alloc_size-7.c: New test.
	* gcc.dg/attr-alloc_size-8.c: New test.
	* gcc.dg/attr-alloc_size-9.c: New test.
	* gcc/testsuite/gcc.dg/errno-1.c: Adjust.

From-SVN: r243470