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| 1 // Copyright 2006 The RE2 Authors. All Rights Reserved. | |
| 2 // Use of this source code is governed by a BSD-style | |
| 3 // license that can be found in the LICENSE file. | |
| 4 | |
| 5 // Dump the regexp into a string showing structure. | |
| 6 // Tested by parse_unittest.cc | |
| 7 | |
| 8 // This function traverses the regexp recursively, | |
| 9 // meaning that on inputs like Regexp::Simplify of | |
| 10 // a{100}{100}{100}{100}{100}{100}{100}{100}{100}{100}, | |
| 11 // it takes time and space exponential in the size of the | |
| 12 // original regular expression. It can also use stack space | |
| 13 // linear in the size of the regular expression for inputs | |
| 14 // like ((((((((((((((((a*)*)*)*)*)*)*)*)*)*)*)*)*)*)*)*)*. | |
| 15 // IT IS NOT SAFE TO CALL FROM PRODUCTION CODE. | |
| 16 // As a result, Dump is provided only in the testing | |
| 17 // library (see BUILD). | |
| 18 | |
| 19 #include <string> | |
| 20 #include <vector> | |
| 21 #include "util/test.h" | |
| 22 #include "re2/stringpiece.h" | |
| 23 #include "re2/regexp.h" | |
| 24 | |
| 25 // Cause a link error if this file is used outside of testing. | |
| 26 DECLARE_string(test_tmpdir); | |
| 27 | |
| 28 namespace re2 { | |
| 29 | |
| 30 static const char* kOpcodeNames[] = { | |
| 31 "bad", | |
| 32 "no", | |
| 33 "emp", | |
| 34 "lit", | |
| 35 "str", | |
| 36 "cat", | |
| 37 "alt", | |
| 38 "star", | |
| 39 "plus", | |
| 40 "que", | |
| 41 "rep", | |
| 42 "cap", | |
| 43 "dot", | |
| 44 "byte", | |
| 45 "bol", | |
| 46 "eol", | |
| 47 "wb", // kRegexpWordBoundary | |
| 48 "nwb", // kRegexpNoWordBoundary | |
| 49 "bot", | |
| 50 "eot", | |
| 51 "cc", | |
| 52 "match", | |
| 53 }; | |
| 54 | |
| 55 // Create string representation of regexp with explicit structure. | |
| 56 // Nothing pretty, just for testing. | |
| 57 static void DumpRegexpAppending(Regexp* re, string* s) { | |
| 58 if (re->op() < 0 || re->op() >= arraysize(kOpcodeNames)) { | |
| 59 StringAppendF(s, "op%d", re->op()); | |
| 60 } else { | |
| 61 switch (re->op()) { | |
| 62 default: | |
| 63 break; | |
| 64 case kRegexpStar: | |
| 65 case kRegexpPlus: | |
| 66 case kRegexpQuest: | |
| 67 case kRegexpRepeat: | |
| 68 if (re->parse_flags() & Regexp::NonGreedy) | |
| 69 s->append("n"); | |
| 70 break; | |
| 71 } | |
| 72 s->append(kOpcodeNames[re->op()]); | |
| 73 if (re->op() == kRegexpLiteral && (re->parse_flags() & Regexp::FoldCase)) { | |
| 74 Rune r = re->rune(); | |
| 75 if ('a' <= r && r <= 'z') | |
| 76 s->append("fold"); | |
| 77 } | |
| 78 if (re->op() == kRegexpLiteralString && (re->parse_flags() & Regexp::FoldCas
e)) { | |
| 79 for (int i = 0; i < re->nrunes(); i++) { | |
| 80 Rune r = re->runes()[i]; | |
| 81 if ('a' <= r && r <= 'z') { | |
| 82 s->append("fold"); | |
| 83 break; | |
| 84 } | |
| 85 } | |
| 86 } | |
| 87 } | |
| 88 s->append("{"); | |
| 89 switch (re->op()) { | |
| 90 default: | |
| 91 break; | |
| 92 case kRegexpEndText: | |
| 93 if (!(re->parse_flags() & Regexp::WasDollar)) { | |
| 94 s->append("\\z"); | |
| 95 } | |
| 96 break; | |
| 97 case kRegexpLiteral: { | |
| 98 Rune r = re->rune(); | |
| 99 char buf[UTFmax+1]; | |
| 100 buf[runetochar(buf, &r)] = 0; | |
| 101 s->append(buf); | |
| 102 break; | |
| 103 } | |
| 104 case kRegexpLiteralString: | |
| 105 for (int i = 0; i < re->nrunes(); i++) { | |
| 106 Rune r = re->runes()[i]; | |
| 107 char buf[UTFmax+1]; | |
| 108 buf[runetochar(buf, &r)] = 0; | |
| 109 s->append(buf); | |
| 110 } | |
| 111 break; | |
| 112 case kRegexpConcat: | |
| 113 case kRegexpAlternate: | |
| 114 for (int i = 0; i < re->nsub(); i++) | |
| 115 DumpRegexpAppending(re->sub()[i], s); | |
| 116 break; | |
| 117 case kRegexpStar: | |
| 118 case kRegexpPlus: | |
| 119 case kRegexpQuest: | |
| 120 DumpRegexpAppending(re->sub()[0], s); | |
| 121 break; | |
| 122 case kRegexpCapture: | |
| 123 if (re->cap() == 0) | |
| 124 LOG(DFATAL) << "kRegexpCapture cap() == 0"; | |
| 125 if (re->name()) { | |
| 126 s->append(*re->name()); | |
| 127 s->append(":"); | |
| 128 } | |
| 129 DumpRegexpAppending(re->sub()[0], s); | |
| 130 break; | |
| 131 case kRegexpRepeat: | |
| 132 s->append(StringPrintf("%d,%d ", re->min(), re->max())); | |
| 133 DumpRegexpAppending(re->sub()[0], s); | |
| 134 break; | |
| 135 case kRegexpCharClass: { | |
| 136 string sep; | |
| 137 for (CharClass::iterator it = re->cc()->begin(); | |
| 138 it != re->cc()->end(); ++it) { | |
| 139 RuneRange rr = *it; | |
| 140 s->append(sep); | |
| 141 if (rr.lo == rr.hi) | |
| 142 s->append(StringPrintf("%#x", rr.lo)); | |
| 143 else | |
| 144 s->append(StringPrintf("%#x-%#x", rr.lo, rr.hi)); | |
| 145 sep = " "; | |
| 146 } | |
| 147 break; | |
| 148 } | |
| 149 } | |
| 150 s->append("}"); | |
| 151 } | |
| 152 | |
| 153 string Regexp::Dump() { | |
| 154 string s; | |
| 155 | |
| 156 // Make sure being called from a unit test. | |
| 157 if (FLAGS_test_tmpdir.empty()) { | |
| 158 LOG(ERROR) << "Cannot use except for testing."; | |
| 159 return s; | |
| 160 } | |
| 161 | |
| 162 DumpRegexpAppending(this, &s); | |
| 163 return s; | |
| 164 } | |
| 165 | |
| 166 } // namespace re2 | |
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Chromium Code Reviews
Issue 1544433002:
Replace RE2 import with a dependency (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master