automata: fix incorrect use of Aho-Corasick's "standard" semantics #1072
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This fixes a bug in how prefilters were applied for multi-regexes compiled with "all" semantics. It turns out that this corresponds to the regex crate's RegexSet API, but only its `is_match` routine. See the comment on the regression test added in this PR for an explanation of what happened. Basically, it came down to incorrectly using Aho-Corasick's "standard" semantics, which doesn't necessarily report leftmost matches. Since the regex crate is really all about leftmost matching, this can lead to skipping over parts of the haystack and thus lead to missing matches. Fixes #1070
The main reason we used mips before was to get test coverage on a big endian target. Now that mips no longer seems to work[1], I wanted to add at least one other big endian target. From the tier 2 supported platforms[2], the only big endian targets I could find were powerpc and s390x. So we just add both here. [1]: rust-lang/compiler-team#648 [2]: https://doc.rust-lang.org/nightly/rustc/platform-support.html#tier-2-with-host-tools
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This fixes a bug in how prefilters were applied for multi-regexes compiled with "all" semantics. It turns out that this corresponds to the regex crate's RegexSet API, but only its
is_matchroutine.See the comment on the regression test added in this PR for an explanation of what happened. Basically, it came down to incorrectly using Aho-Corasick's "standard" semantics, which doesn't necessarily report leftmost matches. Since the regex crate is really all about leftmost matching, this can lead to skipping over parts of the haystack and thus lead to missing matches.
Fixes #1070