Commit 51be575745adfe21a5367f206c156f2d589ad436 | zig

author	LemonBoy <thatlemon@gmail.com> 2021-10-17 15:52:19+02:00
committer	Andrew Kelley <andrew@ziglang.org> 2021-10-17 16:06:40-04:00
log	51be575745adfe21a5367f206c156f2d589ad436
tree	a888b7e8eb55a0c91c7686ef5b0570c8085bc11d
parent	98a37dfb23202e3f56e1596a19be3fa563f65eeb

std: Fix endless loop in fmt impl

Apparently there's a stage1 bug that may sometimes lead to an endless
loop being generated when unrolling the fmt impl.

Closes #9961

1 files changed, 16 insertions(+), 14 deletions(-)

lib
- std
  - fmt.zig

lib/std/fmt.zig+16-14

...	...	@@ -295,21 +295,21 @@ pub fn format(
295	295	}
296	296
297	297	// Parse the width parameter
298		options.width = init: {
299		if (comptime parser.maybe('[')) {
300		const arg_name = comptime parser.until(']');
	298	options.width = comptime init: {
	299	if (parser.maybe('[')) {
	300	const arg_name = parser.until(']');
301	301
302		if (!comptime parser.maybe(']')) {
	302	if (!parser.maybe(']')) {
303	303	@compileError("Expected closing ]");
304	304	}
305	305
306		const index = comptime meta.fieldIndex(ArgsType, arg_name) orelse
	306	const index = meta.fieldIndex(ArgsType, arg_name) orelse
307	307	@compileError("No argument with name '" ++ arg_name ++ "'");
308		const arg_index = comptime arg_state.nextArg(index);
	308	const arg_index = arg_state.nextArg(index);
309	309
310	310	break :init @field(args, fields_info[arg_index].name);
311	311	} else {
312		break :init comptime parser.number();
	312	break :init parser.number();
313	313	}
314	314	};
315	315
...	...	@@ -321,21 +321,21 @@ pub fn format(
321	321	}
322	322
323	323	// Parse the precision parameter
324		options.precision = init: {
325		if (comptime parser.maybe('[')) {
326		const arg_name = comptime parser.until(']');
	324	options.precision = comptime init: {
	325	if (parser.maybe('[')) {
	326	const arg_name = parser.until(']');
327	327
328		if (!comptime parser.maybe(']')) {
	328	if (!parser.maybe(']')) {
329	329	@compileError("Expected closing ]");
330	330	}
331	331
332		const arg_i = comptime meta.fieldIndex(ArgsType, arg_name) orelse
	332	const arg_i = meta.fieldIndex(ArgsType, arg_name) orelse
333	333	@compileError("No argument with name '" ++ arg_name ++ "'");
334		const arg_to_use = comptime arg_state.nextArg(arg_i);
	334	const arg_to_use = arg_state.nextArg(arg_i);
335	335
336	336	break :init @field(args, fields_info[arg_to_use].name);
337	337	} else {
338		break :init comptime parser.number();
	338	break :init parser.number();
339	339	}
340	340	};
341	341
...	...	@@ -2576,6 +2576,8 @@ test "runtime width specifier" {
2576	2576	var width: usize = 9;
2577	2577	try expectFmt("~~hello~~", "{s:~^[1]}", .{ "hello", width });
2578	2578	try expectFmt("~~hello~~", "{s:~^[width]}", .{ .string = "hello", .width = width });
	2579	try expectFmt(" hello", "{s:[1]}", .{ "hello", width });
	2580	try expectFmt("42 hello", "{d} {s:[2]}", .{ 42, "hello", width });
2579	2581	}
2580	2582
2581	2583	test "runtime precision specifier" {