gcc/ChangeLog:

	PR middle-end/83859
	* attribs.h (struct attr_access): New.
	* attribs.c (decl_attributes): Add an informational note.
	* builtins.c (check_access): Make extern.  Consistently set no-warning
	after issuing a warning.  Handle calls through function pointers.  Set
	no-warning.
	* builtins.h (check_access): Declare.
	* calls.c (rdwr_access_hash): New type.
	(rdwr_map): Same.
	(init_attr_rdwr_indices): New function.
	(maybe_warn_rdwr_sizes): Same.
	(initialize_argument_information): Call init_attr_rdwr_indices.
	Call maybe_warn_rdwr_sizes.
	(get_size_range): Avoid null argument.
	* doc/extend.texi (attribute access): Document new attribute.

gcc/c-family/ChangeLog:

	PR middle-end/83859
	* c-attribs.c (handle_access_attribute): New function.
	(c_common_attribute_table): Add new attribute.
	(get_argument_type): New function.
	(append_access_attrs): New function.
	(get_nonnull_operand): Rename...
	(get_attribute_operand): ...to this.
	* c-common.c (get_nonnull_operand): Rename...
	(get_attribute_operand): ...to this.

gcc/testsuite/ChangeLog:

	PR middle-end/83859
	* c-c++-common/attr-nonstring-8.c: Adjust text of expected warning.
	* gcc.dg/Wstringop-overflow-23.c: New test.
	* gcc.dg/Wstringop-overflow-24.c: New test.
	* gcc.dg/attr-access-read-only.c: New test.
	* gcc.dg/attr-access-read-write.c: New test.
	* gcc.dg/attr-access-read-write-2.c: New test.
	* gcc.dg/attr-access-write-only.c: New test.

From-SVN: r278624