diff options
Diffstat (limited to 'third_party/rust/regex-automata/tests/hybrid')
| -rw-r--r-- | third_party/rust/regex-automata/tests/hybrid/api.rs | 171 | ||||
| -rw-r--r-- | third_party/rust/regex-automata/tests/hybrid/mod.rs | 3 | ||||
| -rw-r--r-- | third_party/rust/regex-automata/tests/hybrid/suite.rs | 347 |
3 files changed, 521 insertions, 0 deletions
diff --git a/third_party/rust/regex-automata/tests/hybrid/api.rs b/third_party/rust/regex-automata/tests/hybrid/api.rs new file mode 100644 index 0000000000..e82d808e34 --- /dev/null +++ b/third_party/rust/regex-automata/tests/hybrid/api.rs @@ -0,0 +1,171 @@ +use std::error::Error; + +use regex_automata::{ + hybrid::dfa::{OverlappingState, DFA}, + nfa::thompson, + HalfMatch, Input, MatchError, +}; + +// Tests that too many cache resets cause the lazy DFA to quit. +// +// We only test this on 64-bit because the test is gingerly crafted based on +// implementation details of cache sizes. It's not a great test because of +// that, but it does check some interesting properties around how positions are +// reported when a search "gives up." +// +// NOTE: If you change something in lazy DFA implementation that causes this +// test to fail by reporting different "gave up" positions, then it's generally +// okay to update the positions in the test below as long as you're sure your +// changes are correct. Namely, it is expected that if there are changes in the +// cache size (or changes in how big things are inside the cache), then its +// utilization may change slightly and thus impact where a search gives up. +// Precisely where a search gives up is not an API guarantee, so changing the +// offsets here is OK. +#[test] +#[cfg(target_pointer_width = "64")] +#[cfg(not(miri))] +fn too_many_cache_resets_cause_quit() -> Result<(), Box<dyn Error>> { + // This is a carefully chosen regex. The idea is to pick one that requires + // some decent number of states (hence the bounded repetition). But we + // specifically choose to create a class with an ASCII letter and a + // non-ASCII letter so that we can check that no new states are created + // once the cache is full. Namely, if we fill up the cache on a haystack + // of 'a's, then in order to match one 'β', a new state will need to be + // created since a 'β' is encoded with multiple bytes. + // + // So we proceed by "filling" up the cache by searching a haystack of just + // 'a's. The cache won't have enough room to add enough states to find the + // match (because of the bounded repetition), which should result in it + // giving up before it finds a match. + // + // Since there's now no more room to create states, we search a haystack + // of 'β' and confirm that it gives up immediately. + let pattern = r"[aβ]{99}"; + let dfa = DFA::builder() + .configure( + // Configure it so that we have the minimum cache capacity + // possible. And that if any resets occur, the search quits. + DFA::config() + .skip_cache_capacity_check(true) + .cache_capacity(0) + .minimum_cache_clear_count(Some(0)), + ) + .thompson(thompson::NFA::config()) + .build(pattern)?; + let mut cache = dfa.create_cache(); + + let haystack = "a".repeat(101).into_bytes(); + let err = MatchError::gave_up(25); + // Notice that we make the same amount of progress in each search! That's + // because the cache is reused and already has states to handle the first + // N bytes. + assert_eq!( + Err(err.clone()), + dfa.try_search_fwd(&mut cache, &Input::new(&haystack)) + ); + assert_eq!( + Err(err.clone()), + dfa.try_search_overlapping_fwd( + &mut cache, + &Input::new(&haystack), + &mut OverlappingState::start() + ), + ); + + let haystack = "β".repeat(101).into_bytes(); + let err = MatchError::gave_up(2); + assert_eq!( + Err(err), + dfa.try_search_fwd(&mut cache, &Input::new(&haystack)) + ); + // no need to test that other find routines quit, since we did that above + + // OK, if we reset the cache, then we should be able to create more states + // and make more progress with searching for betas. + cache.reset(&dfa); + let err = MatchError::gave_up(27); + assert_eq!( + Err(err), + dfa.try_search_fwd(&mut cache, &Input::new(&haystack)) + ); + + // ... switching back to ASCII still makes progress since it just needs to + // set transitions on existing states! + let haystack = "a".repeat(101).into_bytes(); + let err = MatchError::gave_up(13); + assert_eq!( + Err(err), + dfa.try_search_fwd(&mut cache, &Input::new(&haystack)) + ); + + Ok(()) +} + +// Tests that quit bytes in the forward direction work correctly. +#[test] +fn quit_fwd() -> Result<(), Box<dyn Error>> { + let dfa = DFA::builder() + .configure(DFA::config().quit(b'x', true)) + .build("[[:word:]]+$")?; + let mut cache = dfa.create_cache(); + + assert_eq!( + dfa.try_search_fwd(&mut cache, &Input::new("abcxyz")), + Err(MatchError::quit(b'x', 3)), + ); + assert_eq!( + dfa.try_search_overlapping_fwd( + &mut cache, + &Input::new(b"abcxyz"), + &mut OverlappingState::start() + ), + Err(MatchError::quit(b'x', 3)), + ); + + Ok(()) +} + +// Tests that quit bytes in the reverse direction work correctly. +#[test] +fn quit_rev() -> Result<(), Box<dyn Error>> { + let dfa = DFA::builder() + .configure(DFA::config().quit(b'x', true)) + .thompson(thompson::Config::new().reverse(true)) + .build("^[[:word:]]+")?; + let mut cache = dfa.create_cache(); + + assert_eq!( + dfa.try_search_rev(&mut cache, &Input::new("abcxyz")), + Err(MatchError::quit(b'x', 3)), + ); + + Ok(()) +} + +// Tests that if we heuristically enable Unicode word boundaries but then +// instruct that a non-ASCII byte should NOT be a quit byte, then the builder +// will panic. +#[test] +#[should_panic] +fn quit_panics() { + DFA::config().unicode_word_boundary(true).quit(b'\xFF', false); +} + +// This tests an intesting case where even if the Unicode word boundary option +// is disabled, setting all non-ASCII bytes to be quit bytes will cause Unicode +// word boundaries to be enabled. +#[test] +fn unicode_word_implicitly_works() -> Result<(), Box<dyn Error>> { + let mut config = DFA::config(); + for b in 0x80..=0xFF { + config = config.quit(b, true); + } + let dfa = DFA::builder().configure(config).build(r"\b")?; + let mut cache = dfa.create_cache(); + let expected = HalfMatch::must(0, 1); + assert_eq!( + Ok(Some(expected)), + dfa.try_search_fwd(&mut cache, &Input::new(" a")), + ); + Ok(()) +} diff --git a/third_party/rust/regex-automata/tests/hybrid/mod.rs b/third_party/rust/regex-automata/tests/hybrid/mod.rs new file mode 100644 index 0000000000..36667d09cc --- /dev/null +++ b/third_party/rust/regex-automata/tests/hybrid/mod.rs @@ -0,0 +1,3 @@ +mod api; +#[cfg(not(miri))] +mod suite; diff --git a/third_party/rust/regex-automata/tests/hybrid/suite.rs b/third_party/rust/regex-automata/tests/hybrid/suite.rs new file mode 100644 index 0000000000..4aaca66984 --- /dev/null +++ b/third_party/rust/regex-automata/tests/hybrid/suite.rs @@ -0,0 +1,347 @@ +use { + anyhow::Result, + regex_automata::{ + hybrid::{ + dfa::{OverlappingState, DFA}, + regex::{self, Regex}, + }, + nfa::thompson, + util::{prefilter::Prefilter, syntax}, + Anchored, Input, PatternSet, + }, + regex_test::{ + CompiledRegex, Match, RegexTest, SearchKind, Span, TestResult, + TestRunner, + }, +}; + +use crate::{create_input, suite, untestify_kind}; + +const EXPANSIONS: &[&str] = &["is_match", "find", "which"]; + +/// Tests the default configuration of the hybrid NFA/DFA. +#[test] +fn default() -> Result<()> { + let builder = Regex::builder(); + TestRunner::new()? + .expand(EXPANSIONS, |t| t.compiles()) + // Without NFA shrinking, this test blows the default cache capacity. + .blacklist("expensive/regression-many-repeat-no-stack-overflow") + .test_iter(suite()?.iter(), compiler(builder)) + .assert(); + Ok(()) +} + +/// Tests the hybrid NFA/DFA with prefilters enabled. +#[test] +fn prefilter() -> Result<()> { + let my_compiler = |test: &RegexTest, regexes: &[String]| { + // Parse regexes as HIRs so we can get literals to build a prefilter. + let mut hirs = vec![]; + for pattern in regexes.iter() { + hirs.push(syntax::parse_with(pattern, &config_syntax(test))?); + } + let kind = match untestify_kind(test.match_kind()) { + None => return Ok(CompiledRegex::skip()), + Some(kind) => kind, + }; + let pre = Prefilter::from_hirs_prefix(kind, &hirs); + let mut builder = Regex::builder(); + builder.dfa(DFA::config().prefilter(pre)); + compiler(builder)(test, regexes) + }; + TestRunner::new()? + .expand(EXPANSIONS, |t| t.compiles()) + // Without NFA shrinking, this test blows the default cache capacity. + .blacklist("expensive/regression-many-repeat-no-stack-overflow") + .test_iter(suite()?.iter(), my_compiler) + .assert(); + Ok(()) +} + +/// Tests the hybrid NFA/DFA with NFA shrinking enabled. +/// +/// This is *usually* not the configuration one wants for a lazy DFA. NFA +/// shrinking is mostly only advantageous when building a full DFA since it +/// can sharply decrease the amount of time determinization takes. But NFA +/// shrinking is itself otherwise fairly expensive currently. Since a lazy DFA +/// has no compilation time (other than for building the NFA of course) before +/// executing a search, it's usually worth it to forgo NFA shrinking. +/// +/// Nevertheless, we test to make sure everything is OK with NFA shrinking. As +/// a bonus, there are some tests we don't need to skip because they now fit in +/// the default cache capacity. +#[test] +fn nfa_shrink() -> Result<()> { + let mut builder = Regex::builder(); + builder.thompson(thompson::Config::new().shrink(true)); + TestRunner::new()? + .expand(EXPANSIONS, |t| t.compiles()) + .test_iter(suite()?.iter(), compiler(builder)) + .assert(); + Ok(()) +} + +/// Tests the hybrid NFA/DFA when 'starts_for_each_pattern' is enabled for all +/// tests. +#[test] +fn starts_for_each_pattern() -> Result<()> { + let mut builder = Regex::builder(); + builder.dfa(DFA::config().starts_for_each_pattern(true)); + TestRunner::new()? + .expand(EXPANSIONS, |t| t.compiles()) + // Without NFA shrinking, this test blows the default cache capacity. + .blacklist("expensive/regression-many-repeat-no-stack-overflow") + .test_iter(suite()?.iter(), compiler(builder)) + .assert(); + Ok(()) +} + +/// Tests the hybrid NFA/DFA when 'specialize_start_states' is enabled. +#[test] +fn specialize_start_states() -> Result<()> { + let mut builder = Regex::builder(); + builder.dfa(DFA::config().specialize_start_states(true)); + TestRunner::new()? + .expand(EXPANSIONS, |t| t.compiles()) + // Without NFA shrinking, this test blows the default cache capacity. + .blacklist("expensive/regression-many-repeat-no-stack-overflow") + .test_iter(suite()?.iter(), compiler(builder)) + .assert(); + Ok(()) +} + +/// Tests the hybrid NFA/DFA when byte classes are disabled. +/// +/// N.B. Disabling byte classes doesn't avoid any indirection at search time. +/// All it does is cause every byte value to be its own distinct equivalence +/// class. +#[test] +fn no_byte_classes() -> Result<()> { + let mut builder = Regex::builder(); + builder.dfa(DFA::config().byte_classes(false)); + TestRunner::new()? + .expand(EXPANSIONS, |t| t.compiles()) + // Without NFA shrinking, this test blows the default cache capacity. + .blacklist("expensive/regression-many-repeat-no-stack-overflow") + .test_iter(suite()?.iter(), compiler(builder)) + .assert(); + Ok(()) +} + +/// Tests that hybrid NFA/DFA never clears its cache for any test with the +/// default capacity. +/// +/// N.B. If a regex suite test is added that causes the cache to be cleared, +/// then this should just skip that test. (Which can be done by calling the +/// 'blacklist' method on 'TestRunner'.) +#[test] +fn no_cache_clearing() -> Result<()> { + let mut builder = Regex::builder(); + builder.dfa(DFA::config().minimum_cache_clear_count(Some(0))); + TestRunner::new()? + .expand(EXPANSIONS, |t| t.compiles()) + // Without NFA shrinking, this test blows the default cache capacity. + .blacklist("expensive/regression-many-repeat-no-stack-overflow") + .test_iter(suite()?.iter(), compiler(builder)) + .assert(); + Ok(()) +} + +/// Tests the hybrid NFA/DFA when the minimum cache capacity is set. +#[test] +fn min_cache_capacity() -> Result<()> { + let mut builder = Regex::builder(); + builder + .dfa(DFA::config().cache_capacity(0).skip_cache_capacity_check(true)); + TestRunner::new()? + .expand(EXPANSIONS, |t| t.compiles()) + .test_iter(suite()?.iter(), compiler(builder)) + .assert(); + Ok(()) +} + +fn compiler( + mut builder: regex::Builder, +) -> impl FnMut(&RegexTest, &[String]) -> Result<CompiledRegex> { + move |test, regexes| { + // Parse regexes as HIRs for some analysis below. + let mut hirs = vec![]; + for pattern in regexes.iter() { + hirs.push(syntax::parse_with(pattern, &config_syntax(test))?); + } + + // Check if our regex contains things that aren't supported by DFAs. + // That is, Unicode word boundaries when searching non-ASCII text. + if !test.haystack().is_ascii() { + for hir in hirs.iter() { + if hir.properties().look_set().contains_word_unicode() { + return Ok(CompiledRegex::skip()); + } + } + } + if !configure_regex_builder(test, &mut builder) { + return Ok(CompiledRegex::skip()); + } + let re = builder.build_many(®exes)?; + let mut cache = re.create_cache(); + Ok(CompiledRegex::compiled(move |test| -> TestResult { + run_test(&re, &mut cache, test) + })) + } +} + +fn run_test( + re: &Regex, + cache: &mut regex::Cache, + test: &RegexTest, +) -> TestResult { + let input = create_input(test); + match test.additional_name() { + "is_match" => { + TestResult::matched(re.is_match(cache, input.earliest(true))) + } + "find" => match test.search_kind() { + SearchKind::Earliest | SearchKind::Leftmost => { + let input = + input.earliest(test.search_kind() == SearchKind::Earliest); + TestResult::matches( + re.find_iter(cache, input) + .take(test.match_limit().unwrap_or(std::usize::MAX)) + .map(|m| Match { + id: m.pattern().as_usize(), + span: Span { start: m.start(), end: m.end() }, + }), + ) + } + SearchKind::Overlapping => { + try_search_overlapping(re, cache, &input).unwrap() + } + }, + "which" => match test.search_kind() { + SearchKind::Earliest | SearchKind::Leftmost => { + // There are no "which" APIs for standard searches. + TestResult::skip() + } + SearchKind::Overlapping => { + let dfa = re.forward(); + let cache = cache.as_parts_mut().0; + let mut patset = PatternSet::new(dfa.pattern_len()); + dfa.try_which_overlapping_matches(cache, &input, &mut patset) + .unwrap(); + TestResult::which(patset.iter().map(|p| p.as_usize())) + } + }, + name => TestResult::fail(&format!("unrecognized test name: {}", name)), + } +} + +/// Configures the given regex builder with all relevant settings on the given +/// regex test. +/// +/// If the regex test has a setting that is unsupported, then this returns +/// false (implying the test should be skipped). +fn configure_regex_builder( + test: &RegexTest, + builder: &mut regex::Builder, +) -> bool { + let match_kind = match untestify_kind(test.match_kind()) { + None => return false, + Some(k) => k, + }; + + let mut dfa_config = + DFA::config().match_kind(match_kind).unicode_word_boundary(true); + // When doing an overlapping search, we might try to find the start of each + // match with a custom search routine. In that case, we need to tell the + // reverse search (for the start offset) which pattern to look for. The + // only way that API works is when anchored starting states are compiled + // for each pattern. This does technically also enable it for the forward + // DFA, but we're okay with that. + if test.search_kind() == SearchKind::Overlapping { + dfa_config = dfa_config.starts_for_each_pattern(true); + } + builder + .syntax(config_syntax(test)) + .thompson(config_thompson(test)) + .dfa(dfa_config); + true +} + +/// Configuration of a Thompson NFA compiler from a regex test. +fn config_thompson(test: &RegexTest) -> thompson::Config { + let mut lookm = regex_automata::util::look::LookMatcher::new(); + lookm.set_line_terminator(test.line_terminator()); + thompson::Config::new().utf8(test.utf8()).look_matcher(lookm) +} + +/// Configuration of the regex parser from a regex test. +fn config_syntax(test: &RegexTest) -> syntax::Config { + syntax::Config::new() + .case_insensitive(test.case_insensitive()) + .unicode(test.unicode()) + .utf8(test.utf8()) + .line_terminator(test.line_terminator()) +} + +/// Execute an overlapping search, and for each match found, also find its +/// overlapping starting positions. +/// +/// N.B. This routine used to be part of the crate API, but 1) it wasn't clear +/// to me how useful it was and 2) it wasn't clear to me what its semantics +/// should be. In particular, a potentially surprising footgun of this routine +/// that it is worst case *quadratic* in the size of the haystack. Namely, it's +/// possible to report a match at every position, and for every such position, +/// scan all the way to the beginning of the haystack to find the starting +/// position. Typical leftmost non-overlapping searches don't suffer from this +/// because, well, matches can't overlap. So subsequent searches after a match +/// is found don't revisit previously scanned parts of the haystack. +/// +/// Its semantics can be strange for other reasons too. For example, given +/// the regex '.*' and the haystack 'zz', the full set of overlapping matches +/// is: [0, 0], [1, 1], [0, 1], [2, 2], [1, 2], [0, 2]. The ordering of +/// those matches is quite strange, but makes sense when you think about the +/// implementation: an end offset is found left-to-right, and then one or more +/// starting offsets are found right-to-left. +/// +/// Nevertheless, we provide this routine in our test suite because it's +/// useful to test the low level DFA overlapping search and our test suite +/// is written in a way that requires starting offsets. +fn try_search_overlapping( + re: &Regex, + cache: &mut regex::Cache, + input: &Input<'_>, +) -> Result<TestResult> { + let mut matches = vec![]; + let mut fwd_state = OverlappingState::start(); + let (fwd_dfa, rev_dfa) = (re.forward(), re.reverse()); + let (fwd_cache, rev_cache) = cache.as_parts_mut(); + while let Some(end) = { + fwd_dfa.try_search_overlapping_fwd( + fwd_cache, + input, + &mut fwd_state, + )?; + fwd_state.get_match() + } { + let revsearch = input + .clone() + .range(input.start()..end.offset()) + .anchored(Anchored::Pattern(end.pattern())) + .earliest(false); + let mut rev_state = OverlappingState::start(); + while let Some(start) = { + rev_dfa.try_search_overlapping_rev( + rev_cache, + &revsearch, + &mut rev_state, + )?; + rev_state.get_match() + } { + let span = Span { start: start.offset(), end: end.offset() }; + let mat = Match { id: end.pattern().as_usize(), span }; + matches.push(mat); + } + } + Ok(TestResult::matches(matches)) +} |