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Diffstat (limited to 'src/regexp/exec_test.go')
| -rw-r--r-- | src/regexp/exec_test.go | 748 |
1 files changed, 748 insertions, 0 deletions
diff --git a/src/regexp/exec_test.go b/src/regexp/exec_test.go new file mode 100644 index 0000000..5f84426 --- /dev/null +++ b/src/regexp/exec_test.go @@ -0,0 +1,748 @@ +// Copyright 2010 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package regexp + +import ( + "bufio" + "compress/bzip2" + "fmt" + "internal/testenv" + "io" + "os" + "path/filepath" + "regexp/syntax" + "strconv" + "strings" + "testing" + "unicode/utf8" +) + +// TestRE2 tests this package's regexp API against test cases +// considered during RE2's exhaustive tests, which run all possible +// regexps over a given set of atoms and operators, up to a given +// complexity, over all possible strings over a given alphabet, +// up to a given size. Rather than try to link with RE2, we read a +// log file containing the test cases and the expected matches. +// The log file, re2-exhaustive.txt, is generated by running 'make log' +// in the open source RE2 distribution https://github.com/google/re2/. +// +// The test file format is a sequence of stanzas like: +// +// strings +// "abc" +// "123x" +// regexps +// "[a-z]+" +// 0-3;0-3 +// -;- +// "([0-9])([0-9])([0-9])" +// -;- +// -;0-3 0-1 1-2 2-3 +// +// The stanza begins by defining a set of strings, quoted +// using Go double-quote syntax, one per line. Then the +// regexps section gives a sequence of regexps to run on +// the strings. In the block that follows a regexp, each line +// gives the semicolon-separated match results of running +// the regexp on the corresponding string. +// Each match result is either a single -, meaning no match, or a +// space-separated sequence of pairs giving the match and +// submatch indices. An unmatched subexpression formats +// its pair as a single - (not illustrated above). For now +// each regexp run produces two match results, one for a +// ``full match'' that restricts the regexp to matching the entire +// string or nothing, and one for a ``partial match'' that gives +// the leftmost first match found in the string. +// +// Lines beginning with # are comments. Lines beginning with +// a capital letter are test names printed during RE2's test suite +// and are echoed into t but otherwise ignored. +// +// At time of writing, re2-exhaustive.txt is 59 MB but compresses to 385 kB, +// so we store re2-exhaustive.txt.bz2 in the repository and decompress it on the fly. +// +func TestRE2Search(t *testing.T) { + testRE2(t, "testdata/re2-search.txt") +} + +func testRE2(t *testing.T, file string) { + f, err := os.Open(file) + if err != nil { + t.Fatal(err) + } + defer f.Close() + var txt io.Reader + if strings.HasSuffix(file, ".bz2") { + z := bzip2.NewReader(f) + txt = z + file = file[:len(file)-len(".bz2")] // for error messages + } else { + txt = f + } + lineno := 0 + scanner := bufio.NewScanner(txt) + var ( + str []string + input []string + inStrings bool + re *Regexp + refull *Regexp + nfail int + ncase int + ) + for lineno := 1; scanner.Scan(); lineno++ { + line := scanner.Text() + switch { + case line == "": + t.Fatalf("%s:%d: unexpected blank line", file, lineno) + case line[0] == '#': + continue + case 'A' <= line[0] && line[0] <= 'Z': + // Test name. + t.Logf("%s\n", line) + continue + case line == "strings": + str = str[:0] + inStrings = true + case line == "regexps": + inStrings = false + case line[0] == '"': + q, err := strconv.Unquote(line) + if err != nil { + // Fatal because we'll get out of sync. + t.Fatalf("%s:%d: unquote %s: %v", file, lineno, line, err) + } + if inStrings { + str = append(str, q) + continue + } + // Is a regexp. + if len(input) != 0 { + t.Fatalf("%s:%d: out of sync: have %d strings left before %#q", file, lineno, len(input), q) + } + re, err = tryCompile(q) + if err != nil { + if err.Error() == "error parsing regexp: invalid escape sequence: `\\C`" { + // We don't and likely never will support \C; keep going. + continue + } + t.Errorf("%s:%d: compile %#q: %v", file, lineno, q, err) + if nfail++; nfail >= 100 { + t.Fatalf("stopping after %d errors", nfail) + } + continue + } + full := `\A(?:` + q + `)\z` + refull, err = tryCompile(full) + if err != nil { + // Fatal because q worked, so this should always work. + t.Fatalf("%s:%d: compile full %#q: %v", file, lineno, full, err) + } + input = str + case line[0] == '-' || '0' <= line[0] && line[0] <= '9': + // A sequence of match results. + ncase++ + if re == nil { + // Failed to compile: skip results. + continue + } + if len(input) == 0 { + t.Fatalf("%s:%d: out of sync: no input remaining", file, lineno) + } + var text string + text, input = input[0], input[1:] + if !isSingleBytes(text) && strings.Contains(re.String(), `\B`) { + // RE2's \B considers every byte position, + // so it sees 'not word boundary' in the + // middle of UTF-8 sequences. This package + // only considers the positions between runes, + // so it disagrees. Skip those cases. + continue + } + res := strings.Split(line, ";") + if len(res) != len(run) { + t.Fatalf("%s:%d: have %d test results, want %d", file, lineno, len(res), len(run)) + } + for i := range res { + have, suffix := run[i](re, refull, text) + want := parseResult(t, file, lineno, res[i]) + if !same(have, want) { + t.Errorf("%s:%d: %#q%s.FindSubmatchIndex(%#q) = %v, want %v", file, lineno, re, suffix, text, have, want) + if nfail++; nfail >= 100 { + t.Fatalf("stopping after %d errors", nfail) + } + continue + } + b, suffix := match[i](re, refull, text) + if b != (want != nil) { + t.Errorf("%s:%d: %#q%s.MatchString(%#q) = %v, want %v", file, lineno, re, suffix, text, b, !b) + if nfail++; nfail >= 100 { + t.Fatalf("stopping after %d errors", nfail) + } + continue + } + } + + default: + t.Fatalf("%s:%d: out of sync: %s\n", file, lineno, line) + } + } + if err := scanner.Err(); err != nil { + t.Fatalf("%s:%d: %v", file, lineno, err) + } + if len(input) != 0 { + t.Fatalf("%s:%d: out of sync: have %d strings left at EOF", file, lineno, len(input)) + } + t.Logf("%d cases tested", ncase) +} + +var run = []func(*Regexp, *Regexp, string) ([]int, string){ + runFull, + runPartial, + runFullLongest, + runPartialLongest, +} + +func runFull(re, refull *Regexp, text string) ([]int, string) { + refull.longest = false + return refull.FindStringSubmatchIndex(text), "[full]" +} + +func runPartial(re, refull *Regexp, text string) ([]int, string) { + re.longest = false + return re.FindStringSubmatchIndex(text), "" +} + +func runFullLongest(re, refull *Regexp, text string) ([]int, string) { + refull.longest = true + return refull.FindStringSubmatchIndex(text), "[full,longest]" +} + +func runPartialLongest(re, refull *Regexp, text string) ([]int, string) { + re.longest = true + return re.FindStringSubmatchIndex(text), "[longest]" +} + +var match = []func(*Regexp, *Regexp, string) (bool, string){ + matchFull, + matchPartial, + matchFullLongest, + matchPartialLongest, +} + +func matchFull(re, refull *Regexp, text string) (bool, string) { + refull.longest = false + return refull.MatchString(text), "[full]" +} + +func matchPartial(re, refull *Regexp, text string) (bool, string) { + re.longest = false + return re.MatchString(text), "" +} + +func matchFullLongest(re, refull *Regexp, text string) (bool, string) { + refull.longest = true + return refull.MatchString(text), "[full,longest]" +} + +func matchPartialLongest(re, refull *Regexp, text string) (bool, string) { + re.longest = true + return re.MatchString(text), "[longest]" +} + +func isSingleBytes(s string) bool { + for _, c := range s { + if c >= utf8.RuneSelf { + return false + } + } + return true +} + +func tryCompile(s string) (re *Regexp, err error) { + // Protect against panic during Compile. + defer func() { + if r := recover(); r != nil { + err = fmt.Errorf("panic: %v", r) + } + }() + return Compile(s) +} + +func parseResult(t *testing.T, file string, lineno int, res string) []int { + // A single - indicates no match. + if res == "-" { + return nil + } + // Otherwise, a space-separated list of pairs. + n := 1 + for j := 0; j < len(res); j++ { + if res[j] == ' ' { + n++ + } + } + out := make([]int, 2*n) + i := 0 + n = 0 + for j := 0; j <= len(res); j++ { + if j == len(res) || res[j] == ' ' { + // Process a single pair. - means no submatch. + pair := res[i:j] + if pair == "-" { + out[n] = -1 + out[n+1] = -1 + } else { + loStr, hiStr, _ := strings.Cut(pair, "-") + lo, err1 := strconv.Atoi(loStr) + hi, err2 := strconv.Atoi(hiStr) + if err1 != nil || err2 != nil || lo > hi { + t.Fatalf("%s:%d: invalid pair %s", file, lineno, pair) + } + out[n] = lo + out[n+1] = hi + } + n += 2 + i = j + 1 + } + } + return out +} + +func same(x, y []int) bool { + if len(x) != len(y) { + return false + } + for i, xi := range x { + if xi != y[i] { + return false + } + } + return true +} + +// TestFowler runs this package's regexp API against the +// POSIX regular expression tests collected by Glenn Fowler +// at http://www2.research.att.com/~astopen/testregex/testregex.html. +func TestFowler(t *testing.T) { + files, err := filepath.Glob("testdata/*.dat") + if err != nil { + t.Fatal(err) + } + for _, file := range files { + t.Log(file) + testFowler(t, file) + } +} + +var notab = MustCompilePOSIX(`[^\t]+`) + +func testFowler(t *testing.T, file string) { + f, err := os.Open(file) + if err != nil { + t.Error(err) + return + } + defer f.Close() + b := bufio.NewReader(f) + lineno := 0 + lastRegexp := "" +Reading: + for { + lineno++ + line, err := b.ReadString('\n') + if err != nil { + if err != io.EOF { + t.Errorf("%s:%d: %v", file, lineno, err) + } + break Reading + } + + // http://www2.research.att.com/~astopen/man/man1/testregex.html + // + // INPUT FORMAT + // Input lines may be blank, a comment beginning with #, or a test + // specification. A specification is five fields separated by one + // or more tabs. NULL denotes the empty string and NIL denotes the + // 0 pointer. + if line[0] == '#' || line[0] == '\n' { + continue Reading + } + line = line[:len(line)-1] + field := notab.FindAllString(line, -1) + for i, f := range field { + if f == "NULL" { + field[i] = "" + } + if f == "NIL" { + t.Logf("%s:%d: skip: %s", file, lineno, line) + continue Reading + } + } + if len(field) == 0 { + continue Reading + } + + // Field 1: the regex(3) flags to apply, one character per REG_feature + // flag. The test is skipped if REG_feature is not supported by the + // implementation. If the first character is not [BEASKLP] then the + // specification is a global control line. One or more of [BEASKLP] may be + // specified; the test will be repeated for each mode. + // + // B basic BRE (grep, ed, sed) + // E REG_EXTENDED ERE (egrep) + // A REG_AUGMENTED ARE (egrep with negation) + // S REG_SHELL SRE (sh glob) + // K REG_SHELL|REG_AUGMENTED KRE (ksh glob) + // L REG_LITERAL LRE (fgrep) + // + // a REG_LEFT|REG_RIGHT implicit ^...$ + // b REG_NOTBOL lhs does not match ^ + // c REG_COMMENT ignore space and #...\n + // d REG_SHELL_DOT explicit leading . match + // e REG_NOTEOL rhs does not match $ + // f REG_MULTIPLE multiple \n separated patterns + // g FNM_LEADING_DIR testfnmatch only -- match until / + // h REG_MULTIREF multiple digit backref + // i REG_ICASE ignore case + // j REG_SPAN . matches \n + // k REG_ESCAPE \ to escape [...] delimiter + // l REG_LEFT implicit ^... + // m REG_MINIMAL minimal match + // n REG_NEWLINE explicit \n match + // o REG_ENCLOSED (|&) magic inside [@|&](...) + // p REG_SHELL_PATH explicit / match + // q REG_DELIMITED delimited pattern + // r REG_RIGHT implicit ...$ + // s REG_SHELL_ESCAPED \ not special + // t REG_MUSTDELIM all delimiters must be specified + // u standard unspecified behavior -- errors not counted + // v REG_CLASS_ESCAPE \ special inside [...] + // w REG_NOSUB no subexpression match array + // x REG_LENIENT let some errors slide + // y REG_LEFT regexec() implicit ^... + // z REG_NULL NULL subexpressions ok + // $ expand C \c escapes in fields 2 and 3 + // / field 2 is a regsubcomp() expression + // = field 3 is a regdecomp() expression + // + // Field 1 control lines: + // + // C set LC_COLLATE and LC_CTYPE to locale in field 2 + // + // ?test ... output field 5 if passed and != EXPECTED, silent otherwise + // &test ... output field 5 if current and previous passed + // |test ... output field 5 if current passed and previous failed + // ; ... output field 2 if previous failed + // {test ... skip if failed until } + // } end of skip + // + // : comment comment copied as output NOTE + // :comment:test :comment: ignored + // N[OTE] comment comment copied as output NOTE + // T[EST] comment comment + // + // number use number for nmatch (20 by default) + flag := field[0] + switch flag[0] { + case '?', '&', '|', ';', '{', '}': + // Ignore all the control operators. + // Just run everything. + flag = flag[1:] + if flag == "" { + continue Reading + } + case ':': + var ok bool + if _, flag, ok = strings.Cut(flag[1:], ":"); !ok { + t.Logf("skip: %s", line) + continue Reading + } + case 'C', 'N', 'T', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + t.Logf("skip: %s", line) + continue Reading + } + + // Can check field count now that we've handled the myriad comment formats. + if len(field) < 4 { + t.Errorf("%s:%d: too few fields: %s", file, lineno, line) + continue Reading + } + + // Expand C escapes (a.k.a. Go escapes). + if strings.Contains(flag, "$") { + f := `"` + field[1] + `"` + if field[1], err = strconv.Unquote(f); err != nil { + t.Errorf("%s:%d: cannot unquote %s", file, lineno, f) + } + f = `"` + field[2] + `"` + if field[2], err = strconv.Unquote(f); err != nil { + t.Errorf("%s:%d: cannot unquote %s", file, lineno, f) + } + } + + // Field 2: the regular expression pattern; SAME uses the pattern from + // the previous specification. + // + if field[1] == "SAME" { + field[1] = lastRegexp + } + lastRegexp = field[1] + + // Field 3: the string to match. + text := field[2] + + // Field 4: the test outcome... + ok, shouldCompile, shouldMatch, pos := parseFowlerResult(field[3]) + if !ok { + t.Errorf("%s:%d: cannot parse result %#q", file, lineno, field[3]) + continue Reading + } + + // Field 5: optional comment appended to the report. + + Testing: + // Run test once for each specified capital letter mode that we support. + for _, c := range flag { + pattern := field[1] + syn := syntax.POSIX | syntax.ClassNL + switch c { + default: + continue Testing + case 'E': + // extended regexp (what we support) + case 'L': + // literal + pattern = QuoteMeta(pattern) + } + + for _, c := range flag { + switch c { + case 'i': + syn |= syntax.FoldCase + } + } + + re, err := compile(pattern, syn, true) + if err != nil { + if shouldCompile { + t.Errorf("%s:%d: %#q did not compile", file, lineno, pattern) + } + continue Testing + } + if !shouldCompile { + t.Errorf("%s:%d: %#q should not compile", file, lineno, pattern) + continue Testing + } + match := re.MatchString(text) + if match != shouldMatch { + t.Errorf("%s:%d: %#q.Match(%#q) = %v, want %v", file, lineno, pattern, text, match, shouldMatch) + continue Testing + } + have := re.FindStringSubmatchIndex(text) + if (len(have) > 0) != match { + t.Errorf("%s:%d: %#q.Match(%#q) = %v, but %#q.FindSubmatchIndex(%#q) = %v", file, lineno, pattern, text, match, pattern, text, have) + continue Testing + } + if len(have) > len(pos) { + have = have[:len(pos)] + } + if !same(have, pos) { + t.Errorf("%s:%d: %#q.FindSubmatchIndex(%#q) = %v, want %v", file, lineno, pattern, text, have, pos) + } + } + } +} + +func parseFowlerResult(s string) (ok, compiled, matched bool, pos []int) { + // Field 4: the test outcome. This is either one of the posix error + // codes (with REG_ omitted) or the match array, a list of (m,n) + // entries with m and n being first and last+1 positions in the + // field 3 string, or NULL if REG_NOSUB is in effect and success + // is expected. BADPAT is acceptable in place of any regcomp(3) + // error code. The match[] array is initialized to (-2,-2) before + // each test. All array elements from 0 to nmatch-1 must be specified + // in the outcome. Unspecified endpoints (offset -1) are denoted by ?. + // Unset endpoints (offset -2) are denoted by X. {x}(o:n) denotes a + // matched (?{...}) expression, where x is the text enclosed by {...}, + // o is the expression ordinal counting from 1, and n is the length of + // the unmatched portion of the subject string. If x starts with a + // number then that is the return value of re_execf(), otherwise 0 is + // returned. + switch { + case s == "": + // Match with no position information. + ok = true + compiled = true + matched = true + return + case s == "NOMATCH": + // Match failure. + ok = true + compiled = true + matched = false + return + case 'A' <= s[0] && s[0] <= 'Z': + // All the other error codes are compile errors. + ok = true + compiled = false + return + } + compiled = true + + var x []int + for s != "" { + var end byte = ')' + if len(x)%2 == 0 { + if s[0] != '(' { + ok = false + return + } + s = s[1:] + end = ',' + } + i := 0 + for i < len(s) && s[i] != end { + i++ + } + if i == 0 || i == len(s) { + ok = false + return + } + var v = -1 + var err error + if s[:i] != "?" { + v, err = strconv.Atoi(s[:i]) + if err != nil { + ok = false + return + } + } + x = append(x, v) + s = s[i+1:] + } + if len(x)%2 != 0 { + ok = false + return + } + ok = true + matched = true + pos = x + return +} + +var text []byte + +func makeText(n int) []byte { + if len(text) >= n { + return text[:n] + } + text = make([]byte, n) + x := ^uint32(0) + for i := range text { + x += x + x ^= 1 + if int32(x) < 0 { + x ^= 0x88888eef + } + if x%31 == 0 { + text[i] = '\n' + } else { + text[i] = byte(x%(0x7E+1-0x20) + 0x20) + } + } + return text +} + +func BenchmarkMatch(b *testing.B) { + isRaceBuilder := strings.HasSuffix(testenv.Builder(), "-race") + + for _, data := range benchData { + r := MustCompile(data.re) + for _, size := range benchSizes { + if (isRaceBuilder || testing.Short()) && size.n > 1<<10 { + continue + } + t := makeText(size.n) + b.Run(data.name+"/"+size.name, func(b *testing.B) { + b.SetBytes(int64(size.n)) + for i := 0; i < b.N; i++ { + if r.Match(t) { + b.Fatal("match!") + } + } + }) + } + } +} + +func BenchmarkMatch_onepass_regex(b *testing.B) { + isRaceBuilder := strings.HasSuffix(testenv.Builder(), "-race") + r := MustCompile(`(?s)\A.*\z`) + if r.onepass == nil { + b.Fatalf("want onepass regex, but %q is not onepass", r) + } + for _, size := range benchSizes { + if (isRaceBuilder || testing.Short()) && size.n > 1<<10 { + continue + } + t := makeText(size.n) + b.Run(size.name, func(b *testing.B) { + b.SetBytes(int64(size.n)) + b.ReportAllocs() + for i := 0; i < b.N; i++ { + if !r.Match(t) { + b.Fatal("not match!") + } + } + }) + } +} + +var benchData = []struct{ name, re string }{ + {"Easy0", "ABCDEFGHIJKLMNOPQRSTUVWXYZ$"}, + {"Easy0i", "(?i)ABCDEFGHIJklmnopqrstuvwxyz$"}, + {"Easy1", "A[AB]B[BC]C[CD]D[DE]E[EF]F[FG]G[GH]H[HI]I[IJ]J$"}, + {"Medium", "[XYZ]ABCDEFGHIJKLMNOPQRSTUVWXYZ$"}, + {"Hard", "[ -~]*ABCDEFGHIJKLMNOPQRSTUVWXYZ$"}, + {"Hard1", "ABCD|CDEF|EFGH|GHIJ|IJKL|KLMN|MNOP|OPQR|QRST|STUV|UVWX|WXYZ"}, +} + +var benchSizes = []struct { + name string + n int +}{ + {"16", 16}, + {"32", 32}, + {"1K", 1 << 10}, + {"32K", 32 << 10}, + {"1M", 1 << 20}, + {"32M", 32 << 20}, +} + +func TestLongest(t *testing.T) { + re, err := Compile(`a(|b)`) + if err != nil { + t.Fatal(err) + } + if g, w := re.FindString("ab"), "a"; g != w { + t.Errorf("first match was %q, want %q", g, w) + } + re.Longest() + if g, w := re.FindString("ab"), "ab"; g != w { + t.Errorf("longest match was %q, want %q", g, w) + } +} + +// TestProgramTooLongForBacktrack tests that a regex which is too long +// for the backtracker still executes properly. +func TestProgramTooLongForBacktrack(t *testing.T) { + longRegex := MustCompile(`(one|two|three|four|five|six|seven|eight|nine|ten|eleven|twelve|thirteen|fourteen|fifteen|sixteen|seventeen|eighteen|nineteen|twenty|twentyone|twentytwo|twentythree|twentyfour|twentyfive|twentysix|twentyseven|twentyeight|twentynine|thirty|thirtyone|thirtytwo|thirtythree|thirtyfour|thirtyfive|thirtysix|thirtyseven|thirtyeight|thirtynine|forty|fortyone|fortytwo|fortythree|fortyfour|fortyfive|fortysix|fortyseven|fortyeight|fortynine|fifty|fiftyone|fiftytwo|fiftythree|fiftyfour|fiftyfive|fiftysix|fiftyseven|fiftyeight|fiftynine|sixty|sixtyone|sixtytwo|sixtythree|sixtyfour|sixtyfive|sixtysix|sixtyseven|sixtyeight|sixtynine|seventy|seventyone|seventytwo|seventythree|seventyfour|seventyfive|seventysix|seventyseven|seventyeight|seventynine|eighty|eightyone|eightytwo|eightythree|eightyfour|eightyfive|eightysix|eightyseven|eightyeight|eightynine|ninety|ninetyone|ninetytwo|ninetythree|ninetyfour|ninetyfive|ninetysix|ninetyseven|ninetyeight|ninetynine|onehundred)`) + if !longRegex.MatchString("two") { + t.Errorf("longRegex.MatchString(\"two\") was false, want true") + } + if longRegex.MatchString("xxx") { + t.Errorf("longRegex.MatchString(\"xxx\") was true, want false") + } +} |