Add error code for unsupported PCRE cases (RE_EUNSUPPPCRE), reject one. #447
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There's extra error codes in #440 for regexes that aren't UNSATISFIABLE per se, but depend on particular corner cases in PCRE that probably aren't worth supporting in an automata-based implementation. Add a test case for one, tests/pcre/in48.re: ^a|$[^x]b* This is a tricky one to handle properly; according to PCRE it should match either "a<anything...>" OR "\n", but nothing else. The newline match is because $ is a non-input-consuming check that evaluation is either at the end of input, or at a newline immediately before the end. In this case `$[^x]b*` matches exactly one newline; it's equivalent to "$\n". This probably isn't worth supporting, but we can detect cases where a potential newline match appears after a $ and reject them as an unsupported PCRE behavior.
silentbicycle
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Oct 19, 2023
…is' into sv/integrate-combinable-DFA-capture-resolution--fuzzing-branch Integrate #447's changes for continuing local fuzzing. It hasn't been reviewed yet.
katef
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Oct 29, 2023
src/libre/ast.h
Outdated
| @@ -98,6 +98,7 @@ enum ast_flags { | |||
| AST_FLAG_ANCHORED_START = 1 << 6, | |||
| AST_FLAG_ANCHORED_END = 1 << 7, | |||
| AST_FLAG_END_NL = 1 << 8, | |||
| AST_FLAG_MATCHES_1NEWLINE= 1 << 9, | |||
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There will be even more niche start/end anchor flags coming soon. Expressing PCRE's anchoring rules statically gets complicated.
katef
reviewed
Nov 7, 2023
|
I merged in a recent main and spent a bit more time trying to actually hit the possibly unreachable branch above. |
Ranges using named endpoints are currently rejected with "Unsupported operator".
katef
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Jan 11, 2024
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There's extra error codes in #440 for regexes that aren't UNSATISFIABLE per se, but depend on particular corner cases in PCRE that probably aren't worth supporting in an automata-based implementation.
Add a test case for one, tests/pcre/in48.re:
^a|$[^x]b*This is a tricky one to handle properly; according to PCRE it should match either "a<anything...>" OR "\n", but nothing else. The newline match is because $ is a non-input-consuming check that evaluation is either at the end of input, or at a newline immediately before the end. In this case
$[^x]b*matches exactly one newline; it's equivalent to "$\n". This probably isn't worth supporting, but we can detect cases where a potential newline match appears after a $ and reject them as an unsupported PCRE behavior.