The Tor Browser / file comparison
comparison: js/src/vm/MatchPairs.h
js/src/vm/MatchPairs.h
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
equal
deleted
inserted
replaced
| -1:000000000000 | 0:0edf7761c87d |
|---|---|
| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- | |
| 2 * vim: set ts=8 sts=4 et sw=4 tw=99: | |
| 3 * This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 #ifndef vm_MatchPairs_h | |
| 8 #define vm_MatchPairs_h | |
| 9 | |
| 10 #include "jsalloc.h" | |
| 11 | |
| 12 #include "ds/LifoAlloc.h" | |
| 13 #include "js/Vector.h" | |
| 14 | |
| 15 /* | |
| 16 * RegExp match results are succinctly represented by pairs of integer | |
| 17 * indices delimiting (start, limit] segments of the input string. | |
| 18 * | |
| 19 * The pair count for a given RegExp match is the capturing parentheses | |
| 20 * count plus one for the "0 capturing paren" whole text match. | |
| 21 */ | |
| 22 | |
| 23 namespace js { | |
| 24 | |
| 25 struct MatchPair | |
| 26 { | |
| 27 int start; | |
| 28 int limit; | |
| 29 | |
| 30 MatchPair() | |
| 31 : start(-1), limit(-1) | |
| 32 { } | |
| 33 | |
| 34 MatchPair(int start, int limit) | |
| 35 : start(start), limit(limit) | |
| 36 { } | |
| 37 | |
| 38 size_t length() const { JS_ASSERT(!isUndefined()); return limit - start; } | |
| 39 bool isEmpty() const { return length() == 0; } | |
| 40 bool isUndefined() const { return start < 0; } | |
| 41 | |
| 42 void displace(size_t amount) { | |
| 43 start += (start < 0) ? 0 : amount; | |
| 44 limit += (limit < 0) ? 0 : amount; | |
| 45 } | |
| 46 | |
| 47 inline bool check() const { | |
| 48 JS_ASSERT(limit >= start); | |
| 49 JS_ASSERT_IF(start < 0, start == -1); | |
| 50 JS_ASSERT_IF(limit < 0, limit == -1); | |
| 51 return true; | |
| 52 } | |
| 53 }; | |
| 54 | |
| 55 /* Base class for RegExp execution output. */ | |
| 56 class MatchPairs | |
| 57 { | |
| 58 protected: | |
| 59 size_t pairCount_; /* Length of pairs_. */ | |
| 60 MatchPair *pairs_; /* Raw pointer into an allocated MatchPair buffer. */ | |
| 61 | |
| 62 protected: | |
| 63 /* Not used directly: use ScopedMatchPairs or VectorMatchPairs. */ | |
| 64 MatchPairs() | |
| 65 : pairCount_(0), pairs_(nullptr) | |
| 66 { } | |
| 67 | |
| 68 protected: | |
| 69 /* Functions used by friend classes. */ | |
| 70 friend class RegExpShared; | |
| 71 friend class RegExpStatics; | |
| 72 | |
| 73 /* MatchPair buffer allocator: set pairs_ and pairCount_. */ | |
| 74 virtual bool allocOrExpandArray(size_t pairCount) = 0; | |
| 75 | |
| 76 bool initArray(size_t pairCount); | |
| 77 bool initArrayFrom(MatchPairs ©From); | |
| 78 void forgetArray() { pairs_ = nullptr; } | |
| 79 | |
| 80 void displace(size_t disp); | |
| 81 void checkAgainst(size_t inputLength) { | |
| 82 #ifdef DEBUG | |
| 83 for (size_t i = 0; i < pairCount_; i++) { | |
| 84 const MatchPair &p = pair(i); | |
| 85 JS_ASSERT(p.check()); | |
| 86 if (p.isUndefined()) | |
| 87 continue; | |
| 88 JS_ASSERT(size_t(p.limit) <= inputLength); | |
| 89 } | |
| 90 #endif | |
| 91 } | |
| 92 | |
| 93 public: | |
| 94 /* Querying functions in the style of RegExpStatics. */ | |
| 95 bool empty() const { return pairCount_ == 0; } | |
| 96 size_t pairCount() const { JS_ASSERT(pairCount_ > 0); return pairCount_; } | |
| 97 size_t parenCount() const { return pairCount_ - 1; } | |
| 98 | |
| 99 public: | |
| 100 unsigned *rawBuf() const { return reinterpret_cast<unsigned *>(pairs_); } | |
| 101 size_t length() const { return pairCount_; } | |
| 102 | |
| 103 /* Pair accessors. */ | |
| 104 const MatchPair &pair(size_t i) const { | |
| 105 JS_ASSERT(pairCount_ && i < pairCount_); | |
| 106 JS_ASSERT(pairs_); | |
| 107 return pairs_[i]; | |
| 108 } | |
| 109 | |
| 110 const MatchPair &operator[](size_t i) const { return pair(i); } | |
| 111 }; | |
| 112 | |
| 113 /* MatchPairs allocated into temporary storage, removed when out of scope. */ | |
| 114 class ScopedMatchPairs : public MatchPairs | |
| 115 { | |
| 116 LifoAllocScope lifoScope_; | |
| 117 | |
| 118 public: | |
| 119 /* Constructs an implicit LifoAllocScope. */ | |
| 120 ScopedMatchPairs(LifoAlloc *lifoAlloc) | |
| 121 : lifoScope_(lifoAlloc) | |
| 122 { } | |
| 123 | |
| 124 const MatchPair &operator[](size_t i) const { return pair(i); } | |
| 125 | |
| 126 protected: | |
| 127 bool allocOrExpandArray(size_t pairCount); | |
| 128 }; | |
| 129 | |
| 130 /* | |
| 131 * MatchPairs allocated into permanent storage, for RegExpStatics. | |
| 132 * The Vector of MatchPairs is reusable by Vector expansion. | |
| 133 */ | |
| 134 class VectorMatchPairs : public MatchPairs | |
| 135 { | |
| 136 Vector<MatchPair, 10, SystemAllocPolicy> vec_; | |
| 137 | |
| 138 public: | |
| 139 VectorMatchPairs() { | |
| 140 vec_.clear(); | |
| 141 } | |
| 142 | |
| 143 const MatchPair &operator[](size_t i) const { return pair(i); } | |
| 144 | |
| 145 protected: | |
| 146 friend class RegExpStatics; | |
| 147 bool allocOrExpandArray(size_t pairCount); | |
| 148 }; | |
| 149 | |
| 150 /* | |
| 151 * Passes either MatchPair or MatchPairs through ExecuteRegExp() | |
| 152 * to avoid duplication of generic code. | |
| 153 */ | |
| 154 struct MatchConduit | |
| 155 { | |
| 156 union { | |
| 157 MatchPair *pair; | |
| 158 MatchPairs *pairs; | |
| 159 } u; | |
| 160 bool isPair; | |
| 161 | |
| 162 explicit MatchConduit(MatchPair *pair) { | |
| 163 isPair = true; | |
| 164 u.pair = pair; | |
| 165 } | |
| 166 explicit MatchConduit(MatchPairs *pairs) { | |
| 167 isPair = false; | |
| 168 u.pairs = pairs; | |
| 169 } | |
| 170 }; | |
| 171 | |
| 172 } /* namespace js */ | |
| 173 | |
| 174 #endif /* vm_MatchPairs_h */ |
