gcc/ChangeLog:

	PR middle-end/77735
	* builtins.c (string_length): New function.
	(c_strlen): Use string_length.  Correctly handle wide strings.
	* gimple-ssa-sprintf.c (target_max_value, target_size_max): New
	functions.
	(target_int_max): Call target_max_value.
	(format_result::knownrange): New data member.
	(fmtresult::fmtresult): Define default constructor.
	(format_integer): Use it and set format_result::knownrange.
	Handle global constants.
	(format_floating_max): Add third argument.
	(format_floating): Recompute maximum value for %a for each argument.
	(get_string_length): Use fmtresult default ctor.
	(format_string): Set format_result::knownrange.
	(format_directive): Check format_result::knownrange.
	(add_bytes): Same.  Correct caret placement in diagnostics.
	(pass_sprintf_length::compute_format_length): Set
	format_result::knownrange.
	(pass_sprintf_length::handle_gimple_call): Use target_size_max.

gcc/testsuite/ChangeLog:

	PR middle-end/77735
	* gcc.dg/tree-ssa/builtin-sprintf-2.c: Add test cases.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-1.c: Same.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-2.c: Same.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-3.c: Adjust/relax.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-4.c: Add test cases.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-6.c: XFAIL for LP64 only.
	* gcc.dg/tree-ssa/builtin-sprintf.c: Add test cases.

From-SVN: r241489