| author |  Isaac Freund <mail@isaacfreund.com> 2026-07-04 13:05:28+02:00 |
| committer | Isaac Freund <mail@isaacfreund.com> 2026-07-08 11:49:01+02:00 |
| log | 203e8279539220db84823bb79671c5c6c7d1065f |
| tree | 371be758619ecfb8fc1bc733d199d6fbfdfcd43b |
| parent | e5230c5e8aa95c03e62554ba31bd2f2c7ff86ed9 |
| signature |  Commit is signed but in an unrecognized format. |
parser: check binary op whitespace before parsing rhs
3 files changed, 23 insertions(+), 4 deletions(-)
lib/std/zig/Parse.zig+13-4
| ... | ... | @@ -1637,13 +1637,17 @@ fn parseExprPrecedence(p: *Parse, min_prec: i32) Error!?Node.Index { |
| 1637 | 1637 | if (tok_tag == .keyword_catch) { |
| 1638 | 1638 | _ = try p.parsePayload(); |
| 1639 | 1639 | } |
| 1640 | const rhs = try p.parseExprPrecedence(info.prec + 1) orelse { | |
| 1641 | try p.warn(.expected_expr); | |
| 1642 | return node; | |
| 1643 | }; | |
| 1644 | 1640 | |
| 1641 | // Check for whitespace error before parsing the rhs to facilitate fuzzing. | |
| 1642 | // Consider the case where there is a mismatched whitespace error but the rhs | |
| 1643 | // expression triggers stack overflow when parsing is attempted. In this case | |
| 1644 | // we want to return with an error rather than crashing on stack overflow. | |
| 1645 | 1645 | { |
| 1646 | 1646 | const tok_len = tok_tag.lexeme().?.len; |
| 1647 | if (p.tokenStart(oper_token) + tok_len >= p.source.len) { | |
| 1648 | try p.warn(.expected_expr); | |
| 1649 | return node; | |
| 1650 | } | |
| 1647 | 1651 | const char_before = p.source[p.tokenStart(oper_token) - 1]; |
| 1648 | 1652 | const char_after = p.source[p.tokenStart(oper_token) + tok_len]; |
| 1649 | 1653 | if (tok_tag == .ampersand and char_after == '&') { |
| ... | ... | @@ -1655,6 +1659,11 @@ fn parseExprPrecedence(p: *Parse, min_prec: i32) Error!?Node.Index { |
| 1655 | 1659 | } |
| 1656 | 1660 | } |
| 1657 | 1661 | |
| 1662 | const rhs = try p.parseExprPrecedence(info.prec + 1) orelse { | |
| 1663 | try p.warn(.expected_expr); | |
| 1664 | return node; | |
| 1665 | }; | |
| 1666 | ||
| 1658 | 1667 | node = try p.addNode(.{ |
| 1659 | 1668 | .tag = info.tag, |
| 1660 | 1669 | .main_token = oper_token, |
lib/std/zig/parser_fuzz.zig+9
| ... | ... | @@ -131,6 +131,15 @@ test "nosuspend multi assign" { |
| 131 | 131 | try checkAgainstOracle("test{nosuspend*0,var _=0;}"); |
| 132 | 132 | } |
| 133 | 133 | |
| 134 | // Found using AFL++ | |
| 135 | test "bin op at end of file" { | |
| 136 | try checkAgainstOracle( | |
| 137 | \\test { | |
| 138 | \\ _ = 00 | |
| 139 | \\| | |
| 140 | ); | |
| 141 | } | |
| 142 | ||
| 134 | 143 | fn checkAgainstOracle(source: [:0]const u8) !void { |
| 135 | 144 | var fba_buf: [1 << 18]u8 = undefined; |
| 136 | 145 | var fba: std.heap.FixedBufferAllocator = .init(&fba_buf); |
lib/std/zig/parser_test.zig+1
| ... | ... | @@ -6976,6 +6976,7 @@ test "recovery: missing comma" { |
| 6976 | 6976 | , &[_]Error{ |
| 6977 | 6977 | .expected_comma_after_switch_prong, |
| 6978 | 6978 | .expected_comma_after_switch_prong, |
| 6979 | .mismatched_binary_op_whitespace, | |
| 6979 | 6980 | .expected_expr, |
| 6980 | 6981 | }); |
| 6981 | 6982 | } |