PR tree-optimization/78913 - Probably misleading error reported by -Wformat-length
PR middle-end/77708 - -Wformat-length %s warns for snprintf

gcc/ChangeLog:

	PR middle-end/77708
	* doc/invoke.texi (Warning Options): Document -Wformat-truncation.
	* gimple-ssa-sprintf.c (call_info::reval_used, call_info::warnopt):
	New member functions.
	(format_directive): Used them.
	(add_bytes): Same.
	(pass_sprintf_length::handle_gimple_call): Same.
	* graphite-sese-to-poly.c (tree_int_to_gmp): Increase buffer size
	to avoid truncation for any argument.
	(extract_affine_mul): Same.
	* tree.c (get_file_function_name): Same.

gcc/c-family/ChangeLog:

	PR middle-end/77708
	* c.opt (-Wformat-truncation): New option.

gcc/fortran/ChangeLog:

	PR tree-optimization/78913
	PR middle-end/77708
	* trans-common.c (build_equiv_decl): Increase buffer size to avoid
	truncation for any argument.
	* trans-types.c (gfc_build_logical_type): Same.

gcc/testsuite/ChangeLog:

	PR middle-end/77708
	* gcc.dg/tree-ssa/builtin-snprintf-warn-1.c: New test.
	* gcc.dg/tree-ssa/builtin-snprintf-warn-2.c: New test.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-6.c: XFAIL test cases failing
	due to bug 78969.
	* gcc.dg/format/pr78569.c: Adjust.

From-SVN: r244210