Implement cache optimization for regexp matching - #6486
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makenowjust
marked this pull request as ready for review
November 8, 2022 06:07
This reverts commit 1e6673d.
```
regexec.c: In function ‘reset_match_cache’:
regexec.c:1259:56: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses]
1259 | match_cache[k1 >> 3] &= ((1 << (8 - (k2 & 7) - 1)) - 1 << ((k2 & 7) + 1)) | ((1 << (k1 & 7)) - 1);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
regexec.c:1269:60: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses]
1269 | match_cache[k2 >> 3] &= ((1 << (8 - (k2 & 7) - 1)) - 1 << ((k2 & 7) + 1));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
regexec.c: In function ‘find_cache_index_table’:
regexec.c:1192:11: warning: ‘m’ may be used uninitialized [-Wmaybe-uninitialized]
1192 | if (!(0 <= m && m < num_cache_table && table[m].addr == p)) {
| ~~^~~~
regexec.c: In function ‘match_at’:
regexec.c:1238:12: warning: ‘m1’ is used uninitialized [-Wuninitialized]
1238 | if (table[m1].addr < pbegin && m1 + 1 < num_cache_table) m1++;
| ^
regexec.c:1218:39: note: ‘m1’ was declared here
1218 | int l = 0, r = num_cache_table - 1, m1, m2;
| ^~
regexec.c:1239:12: warning: ‘m2’ is used uninitialized [-Wuninitialized]
1239 | if (table[m2].addr > pend && m2 - 1 > 0) m2--;
| ^
regexec.c:1218:43: note: ‘m2’ was declared here
1218 | int l = 0, r = num_cache_table - 1, m1, m2;
| ^~
```
Currently, the keys for CACHE_MATCH are handled as an `int` type. So we should make sure the table size are smaller than the range of `int`.
Contributor
|
Relaying here just in case, but I think this PR introduced a bug: https://bugs.ruby-lang.org/issues/19104#note-4 module Sass
H = /[0-9a-fA-F]/
UNICODE = /\\#{H}{1,6}[ \t\r\n\f]?/
s = '\u{80}-\u{D7FF}\u{E000}-\u{FFFD}\u{10000}-\u{10FFFF}'
NONASCII = /[#{s}]/
ESCAPE = /#{UNICODE}|\\[^0-9a-fA-F\r\n\f]/
NMSTART = /[_a-zA-Z]|#{NONASCII}|#{ESCAPE}/
NMCHAR = /[a-zA-Z0-9_-]|#{NONASCII}|#{ESCAPE}/
VALID_UNIT = /#{NMSTART}#{NMCHAR}|%*/
100_000.times do
print '.'
raise "WTF?" if "%" !~ VALID_UNIT
end
end |
ghost
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Jan 25, 2026
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module Sass
H = /[0-9a-fA-F]/
UNICODE = /\#{H}{1,6}[ \t\r\n\f]?/
s = '\u{80}-\u{D7FF}\u{E000}-\u{FFFD}\u{10000}-\u{10FFFF}'
NONASCII = /[#{s}]/
ESCAPE = /#{UNICODE}|\[^0-9a-fA-F\r\n\f]/
NMSTART = /[a-zA-Z]|#{NONASCII}|#{ESCAPE}/
NMCHAR = /[a-zA-Z0-9-]|#{NONASCII}|#{ESCAPE}/
VALID_UNIT = /#{NMSTART}#{NMCHAR}|%*/
100_000.times do
print '.'
raise "WTF?" if "%" !~ VALID_UNIT
end
end
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