Commit 581d292381157464ae6f2c88c8a628314f005742 | zig

author	Travis Staloch <twostepted@gmail.com> 2022-12-23 13:10:04-08:00
committer	GitHub <noreply@github.com> 2022-12-23 23:10:04+02:00
log	581d292381157464ae6f2c88c8a628314f005742
tree	1d67f07416fb6d45e54267e459ebda5c7581e1d0
parent	bb62d5105ca02a8b1c959ccf79b9f2861505a150
signature	Signed by PGP key 4AEE18F83AFDEB23

fix overflow found while fuzzing

* allow file level `union {}` to parse as tuple field

this was found while fuzzing zls.

* before this patch the input `union {}` crashed the parser.  after
  this, it parses correctly just like `struct {}`.
* adds behavior tests for both inputs `struct {}` and `union {}`,
  checking that each becomes a file level tuple field.

5 files changed, 30 insertions(+), 1 deletions(-)

lib
- std
  - zig
    Ast.zig
test
- behavior.zig
- behavior

lib/std/zig/Ast.zig+1-1

...	...	@@ -618,7 +618,7 @@ pub fn firstToken(tree: Ast, node: Node.Index) TokenIndex {
618	618	.tagged_union_enum_tag_trailing,
619	619	=> {
620	620	const main_token = main_tokens[n];
621		switch (token_tags[main_token - 1]) {
	621	switch (token_tags[main_token -\| 1]) {
622	622	.keyword_packed, .keyword_extern => end_offset += 1,
623	623	else => {},
624	624	}

test/behavior.zig+1

...	...	@@ -151,6 +151,7 @@ test {
151	151	_ = @import("behavior/const_slice_child.zig");
152	152	_ = @import("behavior/decltest.zig");
153	153	_ = @import("behavior/defer.zig");
	154	_ = @import("behavior/empty_tuple_fields.zig");
154	155	_ = @import("behavior/empty_union.zig");
155	156	_ = @import("behavior/enum.zig");
156	157	_ = @import("behavior/error.zig");

test/behavior/empty_file_level_struct.zig created+1

...	...	@@ -0,0 +1 @@
	1	struct {}

test/behavior/empty_file_level_union.zig created+1

...	...	@@ -0,0 +1 @@
	1	union {}

test/behavior/empty_tuple_fields.zig created+26

...	...	@@ -0,0 +1,26 @@
	1	const std = @import("std");
	2	const builtin = @import("builtin");
	3
	4	test "empty file level struct" {
	5	if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
	6	if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
	7	if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
	8
	9	const T = @import("empty_file_level_struct.zig");
	10	const info = @typeInfo(T);
	11	try std.testing.expectEqual(@as(usize, 1), info.Struct.fields.len);
	12	try std.testing.expectEqualStrings("0", info.Struct.fields[0].name);
	13	try std.testing.expect(@typeInfo(info.Struct.fields[0].type) == .Struct);
	14	}
	15
	16	test "empty file level union" {
	17	if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
	18	if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
	19	if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
	20
	21	const T = @import("empty_file_level_union.zig");
	22	const info = @typeInfo(T);
	23	try std.testing.expectEqual(@as(usize, 1), info.Struct.fields.len);
	24	try std.testing.expectEqualStrings("0", info.Struct.fields[0].name);
	25	try std.testing.expect(@typeInfo(info.Struct.fields[0].type) == .Union);
	26	}