PR middle-end/95353 - spurious -Wstringop-overflow writing to a trailing array plus...

PR middle-end/95353 - spurious -Wstringop-overflow writing to a trailing array plus offset

Also resolves:
PR middle-end/92939 - missing -Wstringop-overflow on negative index from the end of array

gcc/ChangeLog:

	PR middle-end/95353
	PR middle-end/92939
	* builtins.c (inform_access): New function.
	(check_access): Call it.  Add argument.
	(addr_decl_size): Remove.
	(get_range): New function.
	(compute_objsize): New overload.  Only use compute_builtin_object_size
	with raw memory function.
	(check_memop_access): Pass new argument to compute_objsize and
	check_access.
	(expand_builtin_memchr, expand_builtin_strcat): Same.
	(expand_builtin_strcpy, expand_builtin_stpcpy_1): Same.
	(expand_builtin_stpncpy, check_strncat_sizes): Same.
	(expand_builtin_strncat, expand_builtin_strncpy): Same.
	(expand_builtin_memcmp): Same.
	* builtins.h (check_nul_terminated_array): Declare extern.
	(check_access): Add argument.
	(struct access_ref, struct access_data): New structs.
	* gimple-ssa-warn-restrict.c (clamp_offset): New helper.
	(builtin_access::overlap): Call it.
	* tree-object-size.c (decl_init_size): Declare extern.
	(addr_object_size): Correct offset computation.
	* tree-object-size.h (decl_init_size): Declare.
	* tree-ssa-strlen.c (handle_integral_assign): Remove a call
	to maybe_warn_overflow when assigning to an SSA_NAME.

gcc/testsuite/ChangeLog:

	PR middle-end/95353
	PR middle-end/92939
	* c-c++-common/Wstringop-truncation.c: Remove an xfail.
	* gcc.dg/Warray-bounds-46.c: Remove a bogus warning.
	* gcc.dg/Wrestrict-9.c: Disable -Wstringop-overflow.
	* gcc.dg/Wstringop-overflow-12.c: Remove xfails.
	* gcc.dg/Wstringop-overflow-28.c: Same.
	* gcc.dg/builtin-stringop-chk-4.c: Same.
	* gcc.dg/builtin-stringop-chk-5.c: Same.
	* gcc.dg/builtin-stringop-chk-8.c: Same.
	* gcc.dg/strlenopt-74.c: Avoid buffer overflow.
	* gcc.dg/Wstringop-overflow-34.c: New test.
	* gcc.dg/Wstringop-overflow-35.c: New test.
	* gcc.dg/Wstringop-overflow-36.c: New test.
	* gcc.dg/Wstringop-overflow-37.c: New test.
	* gcc.dg/Wstringop-overflow-38.c: New test.