Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 1 | // Copyright 2003-2009 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 | // Regular expression interface RE2. |
| 6 | // |
| 7 | // Originally the PCRE C++ wrapper, but adapted to use |
| 8 | // the new automata-based regular expression engines. |
| 9 | |
| 10 | #include "re2/re2.h" |
| 11 | |
| 12 | #include <stdio.h> |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 13 | #include <string> |
| 14 | #include <pthread.h> |
| 15 | #include <errno.h> |
| 16 | #include "util/util.h" |
| 17 | #include "util/flags.h" |
| 18 | #include "re2/prog.h" |
| 19 | #include "re2/regexp.h" |
| 20 | |
| 21 | DEFINE_bool(trace_re2, false, "trace RE2 execution"); |
| 22 | |
| 23 | namespace re2 { |
| 24 | |
| 25 | // Maximum number of args we can set |
| 26 | static const int kMaxArgs = 16; |
| 27 | static const int kVecSize = 1+kMaxArgs; |
| 28 | |
| 29 | const VariadicFunction2<bool, const StringPiece&, const RE2&, RE2::Arg, RE2::FullMatchN> RE2::FullMatch; |
| 30 | const VariadicFunction2<bool, const StringPiece&, const RE2&, RE2::Arg, RE2::PartialMatchN> RE2::PartialMatch; |
| 31 | const VariadicFunction2<bool, StringPiece*, const RE2&, RE2::Arg, RE2::ConsumeN> RE2::Consume; |
| 32 | const VariadicFunction2<bool, StringPiece*, const RE2&, RE2::Arg, RE2::FindAndConsumeN> RE2::FindAndConsume; |
| 33 | |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 34 | // This will trigger LNK2005 error in MSVC. |
| 35 | #ifndef COMPILER_MSVC |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 36 | const int RE2::Options::kDefaultMaxMem; // initialized in re2.h |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 37 | #endif // COMPILER_MSVC |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 38 | |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 39 | RE2::Options::Options(RE2::CannedOptions opt) |
| 40 | : encoding_(opt == RE2::Latin1 ? EncodingLatin1 : EncodingUTF8), |
| 41 | posix_syntax_(opt == RE2::POSIX), |
| 42 | longest_match_(opt == RE2::POSIX), |
| 43 | log_errors_(opt != RE2::Quiet), |
| 44 | max_mem_(kDefaultMaxMem), |
| 45 | literal_(false), |
| 46 | never_nl_(false), |
| 47 | never_capture_(false), |
| 48 | case_sensitive_(true), |
| 49 | perl_classes_(false), |
| 50 | word_boundary_(false), |
| 51 | one_line_(false) { |
| 52 | } |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 53 | |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 54 | // static empty things for use as const references. |
| 55 | // To avoid global constructors, initialized on demand. |
| 56 | GLOBAL_MUTEX(empty_mutex); |
| 57 | static const string *empty_string; |
| 58 | static const map<string, int> *empty_named_groups; |
| 59 | static const map<int, string> *empty_group_names; |
| 60 | |
| 61 | static void InitEmpty() { |
| 62 | GLOBAL_MUTEX_LOCK(empty_mutex); |
| 63 | if (empty_string == NULL) { |
| 64 | empty_string = new string; |
| 65 | empty_named_groups = new map<string, int>; |
| 66 | empty_group_names = new map<int, string>; |
| 67 | } |
| 68 | GLOBAL_MUTEX_UNLOCK(empty_mutex); |
| 69 | } |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 70 | |
| 71 | // Converts from Regexp error code to RE2 error code. |
| 72 | // Maybe some day they will diverge. In any event, this |
| 73 | // hides the existence of Regexp from RE2 users. |
| 74 | static RE2::ErrorCode RegexpErrorToRE2(re2::RegexpStatusCode code) { |
| 75 | switch (code) { |
| 76 | case re2::kRegexpSuccess: |
| 77 | return RE2::NoError; |
| 78 | case re2::kRegexpInternalError: |
| 79 | return RE2::ErrorInternal; |
| 80 | case re2::kRegexpBadEscape: |
| 81 | return RE2::ErrorBadEscape; |
| 82 | case re2::kRegexpBadCharClass: |
| 83 | return RE2::ErrorBadCharClass; |
| 84 | case re2::kRegexpBadCharRange: |
| 85 | return RE2::ErrorBadCharRange; |
| 86 | case re2::kRegexpMissingBracket: |
| 87 | return RE2::ErrorMissingBracket; |
| 88 | case re2::kRegexpMissingParen: |
| 89 | return RE2::ErrorMissingParen; |
| 90 | case re2::kRegexpTrailingBackslash: |
| 91 | return RE2::ErrorTrailingBackslash; |
| 92 | case re2::kRegexpRepeatArgument: |
| 93 | return RE2::ErrorRepeatArgument; |
| 94 | case re2::kRegexpRepeatSize: |
| 95 | return RE2::ErrorRepeatSize; |
| 96 | case re2::kRegexpRepeatOp: |
| 97 | return RE2::ErrorRepeatOp; |
| 98 | case re2::kRegexpBadPerlOp: |
| 99 | return RE2::ErrorBadPerlOp; |
| 100 | case re2::kRegexpBadUTF8: |
| 101 | return RE2::ErrorBadUTF8; |
| 102 | case re2::kRegexpBadNamedCapture: |
| 103 | return RE2::ErrorBadNamedCapture; |
| 104 | } |
| 105 | return RE2::ErrorInternal; |
| 106 | } |
| 107 | |
| 108 | static string trunc(const StringPiece& pattern) { |
| 109 | if (pattern.size() < 100) |
| 110 | return pattern.as_string(); |
| 111 | return pattern.substr(0, 100).as_string() + "..."; |
| 112 | } |
| 113 | |
| 114 | |
| 115 | RE2::RE2(const char* pattern) { |
| 116 | Init(pattern, DefaultOptions); |
| 117 | } |
| 118 | |
| 119 | RE2::RE2(const string& pattern) { |
| 120 | Init(pattern, DefaultOptions); |
| 121 | } |
| 122 | |
| 123 | RE2::RE2(const StringPiece& pattern) { |
| 124 | Init(pattern, DefaultOptions); |
| 125 | } |
| 126 | |
| 127 | RE2::RE2(const StringPiece& pattern, const Options& options) { |
| 128 | Init(pattern, options); |
| 129 | } |
| 130 | |
| 131 | int RE2::Options::ParseFlags() const { |
| 132 | int flags = Regexp::ClassNL; |
| 133 | switch (encoding()) { |
| 134 | default: |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 135 | if (log_errors()) |
| 136 | LOG(ERROR) << "Unknown encoding " << encoding(); |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 137 | break; |
| 138 | case RE2::Options::EncodingUTF8: |
| 139 | break; |
| 140 | case RE2::Options::EncodingLatin1: |
| 141 | flags |= Regexp::Latin1; |
| 142 | break; |
| 143 | } |
| 144 | |
| 145 | if (!posix_syntax()) |
| 146 | flags |= Regexp::LikePerl; |
| 147 | |
| 148 | if (literal()) |
| 149 | flags |= Regexp::Literal; |
| 150 | |
| 151 | if (never_nl()) |
| 152 | flags |= Regexp::NeverNL; |
| 153 | |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 154 | if (never_capture()) |
| 155 | flags |= Regexp::NeverCapture; |
| 156 | |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 157 | if (!case_sensitive()) |
| 158 | flags |= Regexp::FoldCase; |
| 159 | |
| 160 | if (perl_classes()) |
| 161 | flags |= Regexp::PerlClasses; |
| 162 | |
| 163 | if (word_boundary()) |
| 164 | flags |= Regexp::PerlB; |
| 165 | |
| 166 | if (one_line()) |
| 167 | flags |= Regexp::OneLine; |
| 168 | |
| 169 | return flags; |
| 170 | } |
| 171 | |
| 172 | void RE2::Init(const StringPiece& pattern, const Options& options) { |
| 173 | mutex_ = new Mutex; |
| 174 | pattern_ = pattern.as_string(); |
| 175 | options_.Copy(options); |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 176 | InitEmpty(); |
| 177 | error_ = empty_string; |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 178 | error_code_ = NoError; |
| 179 | suffix_regexp_ = NULL; |
| 180 | entire_regexp_ = NULL; |
| 181 | prog_ = NULL; |
| 182 | rprog_ = NULL; |
| 183 | named_groups_ = NULL; |
| 184 | group_names_ = NULL; |
| 185 | num_captures_ = -1; |
| 186 | |
| 187 | RegexpStatus status; |
| 188 | entire_regexp_ = Regexp::Parse( |
| 189 | pattern_, |
| 190 | static_cast<Regexp::ParseFlags>(options_.ParseFlags()), |
| 191 | &status); |
| 192 | if (entire_regexp_ == NULL) { |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 193 | if (error_ == empty_string) |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 194 | error_ = new string(status.Text()); |
| 195 | if (options_.log_errors()) { |
| 196 | LOG(ERROR) << "Error parsing '" << trunc(pattern_) << "': " |
| 197 | << status.Text(); |
| 198 | } |
| 199 | error_arg_ = status.error_arg().as_string(); |
| 200 | error_code_ = RegexpErrorToRE2(status.code()); |
| 201 | return; |
| 202 | } |
| 203 | |
| 204 | prefix_.clear(); |
| 205 | prefix_foldcase_ = false; |
| 206 | re2::Regexp* suffix; |
| 207 | if (entire_regexp_->RequiredPrefix(&prefix_, &prefix_foldcase_, &suffix)) |
| 208 | suffix_regexp_ = suffix; |
| 209 | else |
| 210 | suffix_regexp_ = entire_regexp_->Incref(); |
| 211 | |
| 212 | // Two thirds of the memory goes to the forward Prog, |
| 213 | // one third to the reverse prog, because the forward |
| 214 | // Prog has two DFAs but the reverse prog has one. |
| 215 | prog_ = suffix_regexp_->CompileToProg(options_.max_mem()*2/3); |
| 216 | if (prog_ == NULL) { |
| 217 | if (options_.log_errors()) |
| 218 | LOG(ERROR) << "Error compiling '" << trunc(pattern_) << "'"; |
| 219 | error_ = new string("pattern too large - compile failed"); |
| 220 | error_code_ = RE2::ErrorPatternTooLarge; |
| 221 | return; |
| 222 | } |
| 223 | |
| 224 | // Could delay this until the first match call that |
| 225 | // cares about submatch information, but the one-pass |
| 226 | // machine's memory gets cut from the DFA memory budget, |
| 227 | // and that is harder to do if the DFA has already |
| 228 | // been built. |
| 229 | is_one_pass_ = prog_->IsOnePass(); |
| 230 | } |
| 231 | |
| 232 | // Returns rprog_, computing it if needed. |
| 233 | re2::Prog* RE2::ReverseProg() const { |
| 234 | MutexLock l(mutex_); |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 235 | if (rprog_ == NULL && error_ == empty_string) { |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 236 | rprog_ = suffix_regexp_->CompileToReverseProg(options_.max_mem()/3); |
| 237 | if (rprog_ == NULL) { |
| 238 | if (options_.log_errors()) |
| 239 | LOG(ERROR) << "Error reverse compiling '" << trunc(pattern_) << "'"; |
| 240 | error_ = new string("pattern too large - reverse compile failed"); |
| 241 | error_code_ = RE2::ErrorPatternTooLarge; |
| 242 | return NULL; |
| 243 | } |
| 244 | } |
| 245 | return rprog_; |
| 246 | } |
| 247 | |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 248 | RE2::~RE2() { |
| 249 | if (suffix_regexp_) |
| 250 | suffix_regexp_->Decref(); |
| 251 | if (entire_regexp_) |
| 252 | entire_regexp_->Decref(); |
| 253 | delete mutex_; |
| 254 | delete prog_; |
| 255 | delete rprog_; |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 256 | if (error_ != empty_string) |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 257 | delete error_; |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 258 | if (named_groups_ != NULL && named_groups_ != empty_named_groups) |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 259 | delete named_groups_; |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 260 | if (group_names_ != NULL && group_names_ != empty_group_names) |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 261 | delete group_names_; |
| 262 | } |
| 263 | |
| 264 | int RE2::ProgramSize() const { |
| 265 | if (prog_ == NULL) |
| 266 | return -1; |
| 267 | return prog_->size(); |
| 268 | } |
| 269 | |
| 270 | // Returns named_groups_, computing it if needed. |
| 271 | const map<string, int>& RE2::NamedCapturingGroups() const { |
| 272 | MutexLock l(mutex_); |
| 273 | if (!ok()) |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 274 | return *empty_named_groups; |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 275 | if (named_groups_ == NULL) { |
| 276 | named_groups_ = suffix_regexp_->NamedCaptures(); |
| 277 | if (named_groups_ == NULL) |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 278 | named_groups_ = empty_named_groups; |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 279 | } |
| 280 | return *named_groups_; |
| 281 | } |
| 282 | |
| 283 | // Returns group_names_, computing it if needed. |
| 284 | const map<int, string>& RE2::CapturingGroupNames() const { |
| 285 | MutexLock l(mutex_); |
| 286 | if (!ok()) |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 287 | return *empty_group_names; |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 288 | if (group_names_ == NULL) { |
| 289 | group_names_ = suffix_regexp_->CaptureNames(); |
| 290 | if (group_names_ == NULL) |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 291 | group_names_ = empty_group_names; |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 292 | } |
| 293 | return *group_names_; |
| 294 | } |
| 295 | |
| 296 | /***** Convenience interfaces *****/ |
| 297 | |
| 298 | bool RE2::FullMatchN(const StringPiece& text, const RE2& re, |
| 299 | const Arg* const args[], int n) { |
| 300 | return re.DoMatch(text, ANCHOR_BOTH, NULL, args, n); |
| 301 | } |
| 302 | |
| 303 | bool RE2::PartialMatchN(const StringPiece& text, const RE2& re, |
| 304 | const Arg* const args[], int n) { |
| 305 | return re.DoMatch(text, UNANCHORED, NULL, args, n); |
| 306 | } |
| 307 | |
| 308 | bool RE2::ConsumeN(StringPiece* input, const RE2& re, |
| 309 | const Arg* const args[], int n) { |
| 310 | int consumed; |
| 311 | if (re.DoMatch(*input, ANCHOR_START, &consumed, args, n)) { |
| 312 | input->remove_prefix(consumed); |
| 313 | return true; |
| 314 | } else { |
| 315 | return false; |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | bool RE2::FindAndConsumeN(StringPiece* input, const RE2& re, |
| 320 | const Arg* const args[], int n) { |
| 321 | int consumed; |
| 322 | if (re.DoMatch(*input, UNANCHORED, &consumed, args, n)) { |
| 323 | input->remove_prefix(consumed); |
| 324 | return true; |
| 325 | } else { |
| 326 | return false; |
| 327 | } |
| 328 | } |
| 329 | |
| 330 | // Returns the maximum submatch needed for the rewrite to be done by Replace(). |
| 331 | // E.g. if rewrite == "foo \\2,\\1", returns 2. |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 332 | int RE2::MaxSubmatch(const StringPiece& rewrite) { |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 333 | int max = 0; |
| 334 | for (const char *s = rewrite.data(), *end = s + rewrite.size(); |
| 335 | s < end; s++) { |
| 336 | if (*s == '\\') { |
| 337 | s++; |
| 338 | int c = (s < end) ? *s : -1; |
| 339 | if (isdigit(c)) { |
| 340 | int n = (c - '0'); |
| 341 | if (n > max) |
| 342 | max = n; |
| 343 | } |
| 344 | } |
| 345 | } |
| 346 | return max; |
| 347 | } |
| 348 | |
| 349 | bool RE2::Replace(string *str, |
| 350 | const RE2& re, |
| 351 | const StringPiece& rewrite) { |
| 352 | StringPiece vec[kVecSize]; |
| 353 | int nvec = 1 + MaxSubmatch(rewrite); |
| 354 | if (nvec > arraysize(vec)) |
| 355 | return false; |
| 356 | if (!re.Match(*str, 0, str->size(), UNANCHORED, vec, nvec)) |
| 357 | return false; |
| 358 | |
| 359 | string s; |
| 360 | if (!re.Rewrite(&s, rewrite, vec, nvec)) |
| 361 | return false; |
| 362 | |
| 363 | assert(vec[0].begin() >= str->data()); |
| 364 | assert(vec[0].end() <= str->data()+str->size()); |
| 365 | str->replace(vec[0].data() - str->data(), vec[0].size(), s); |
| 366 | return true; |
| 367 | } |
| 368 | |
| 369 | int RE2::GlobalReplace(string *str, |
| 370 | const RE2& re, |
| 371 | const StringPiece& rewrite) { |
| 372 | StringPiece vec[kVecSize]; |
| 373 | int nvec = 1 + MaxSubmatch(rewrite); |
| 374 | if (nvec > arraysize(vec)) |
| 375 | return false; |
| 376 | |
| 377 | const char* p = str->data(); |
| 378 | const char* ep = p + str->size(); |
| 379 | const char* lastend = NULL; |
| 380 | string out; |
| 381 | int count = 0; |
| 382 | while (p <= ep) { |
| 383 | if (!re.Match(*str, p - str->data(), str->size(), UNANCHORED, vec, nvec)) |
| 384 | break; |
| 385 | if (p < vec[0].begin()) |
| 386 | out.append(p, vec[0].begin() - p); |
| 387 | if (vec[0].begin() == lastend && vec[0].size() == 0) { |
| 388 | // Disallow empty match at end of last match: skip ahead. |
| 389 | if (p < ep) |
| 390 | out.append(p, 1); |
| 391 | p++; |
| 392 | continue; |
| 393 | } |
| 394 | re.Rewrite(&out, rewrite, vec, nvec); |
| 395 | p = vec[0].end(); |
| 396 | lastend = p; |
| 397 | count++; |
| 398 | } |
| 399 | |
| 400 | if (count == 0) |
| 401 | return 0; |
| 402 | |
| 403 | if (p < ep) |
| 404 | out.append(p, ep - p); |
| 405 | swap(out, *str); |
| 406 | return count; |
| 407 | } |
| 408 | |
| 409 | bool RE2::Extract(const StringPiece &text, |
| 410 | const RE2& re, |
| 411 | const StringPiece &rewrite, |
| 412 | string *out) { |
| 413 | StringPiece vec[kVecSize]; |
| 414 | int nvec = 1 + MaxSubmatch(rewrite); |
| 415 | if (nvec > arraysize(vec)) |
| 416 | return false; |
| 417 | |
| 418 | if (!re.Match(text, 0, text.size(), UNANCHORED, vec, nvec)) |
| 419 | return false; |
| 420 | |
| 421 | out->clear(); |
| 422 | return re.Rewrite(out, rewrite, vec, nvec); |
| 423 | } |
| 424 | |
| 425 | string RE2::QuoteMeta(const StringPiece& unquoted) { |
| 426 | string result; |
| 427 | result.reserve(unquoted.size() << 1); |
| 428 | |
| 429 | // Escape any ascii character not in [A-Za-z_0-9]. |
| 430 | // |
| 431 | // Note that it's legal to escape a character even if it has no |
| 432 | // special meaning in a regular expression -- so this function does |
| 433 | // that. (This also makes it identical to the perl function of the |
| 434 | // same name except for the null-character special case; |
| 435 | // see `perldoc -f quotemeta`.) |
| 436 | for (int ii = 0; ii < unquoted.length(); ++ii) { |
| 437 | // Note that using 'isalnum' here raises the benchmark time from |
| 438 | // 32ns to 58ns: |
| 439 | if ((unquoted[ii] < 'a' || unquoted[ii] > 'z') && |
| 440 | (unquoted[ii] < 'A' || unquoted[ii] > 'Z') && |
| 441 | (unquoted[ii] < '0' || unquoted[ii] > '9') && |
| 442 | unquoted[ii] != '_' && |
| 443 | // If this is the part of a UTF8 or Latin1 character, we need |
| 444 | // to copy this byte without escaping. Experimentally this is |
| 445 | // what works correctly with the regexp library. |
| 446 | !(unquoted[ii] & 128)) { |
| 447 | if (unquoted[ii] == '\0') { // Special handling for null chars. |
| 448 | // Note that this special handling is not strictly required for RE2, |
| 449 | // but this quoting is required for other regexp libraries such as |
| 450 | // PCRE. |
| 451 | // Can't use "\\0" since the next character might be a digit. |
| 452 | result += "\\x00"; |
| 453 | continue; |
| 454 | } |
| 455 | result += '\\'; |
| 456 | } |
| 457 | result += unquoted[ii]; |
| 458 | } |
| 459 | |
| 460 | return result; |
| 461 | } |
| 462 | |
| 463 | bool RE2::PossibleMatchRange(string* min, string* max, int maxlen) const { |
| 464 | if (prog_ == NULL) |
| 465 | return false; |
| 466 | |
| 467 | int n = prefix_.size(); |
| 468 | if (n > maxlen) |
| 469 | n = maxlen; |
| 470 | |
| 471 | // Determine initial min max from prefix_ literal. |
| 472 | string pmin, pmax; |
| 473 | pmin = prefix_.substr(0, n); |
| 474 | pmax = prefix_.substr(0, n); |
| 475 | if (prefix_foldcase_) { |
| 476 | // prefix is ASCII lowercase; change pmin to uppercase. |
| 477 | for (int i = 0; i < n; i++) { |
| 478 | if ('a' <= pmin[i] && pmin[i] <= 'z') |
| 479 | pmin[i] += 'A' - 'a'; |
| 480 | } |
| 481 | } |
| 482 | |
| 483 | // Add to prefix min max using PossibleMatchRange on regexp. |
| 484 | string dmin, dmax; |
| 485 | maxlen -= n; |
| 486 | if (maxlen > 0 && prog_->PossibleMatchRange(&dmin, &dmax, maxlen)) { |
| 487 | pmin += dmin; |
| 488 | pmax += dmax; |
| 489 | } else if (pmax.size() > 0) { |
| 490 | // prog_->PossibleMatchRange has failed us, |
| 491 | // but we still have useful information from prefix_. |
| 492 | // Round up pmax to allow any possible suffix. |
| 493 | pmax = PrefixSuccessor(pmax); |
| 494 | } else { |
| 495 | // Nothing useful. |
| 496 | *min = ""; |
| 497 | *max = ""; |
| 498 | return false; |
| 499 | } |
| 500 | |
| 501 | *min = pmin; |
| 502 | *max = pmax; |
| 503 | return true; |
| 504 | } |
| 505 | |
| 506 | // Avoid possible locale nonsense in standard strcasecmp. |
| 507 | // The string a is known to be all lowercase. |
| 508 | static int ascii_strcasecmp(const char* a, const char* b, int len) { |
| 509 | const char *ae = a + len; |
| 510 | |
| 511 | for (; a < ae; a++, b++) { |
| 512 | uint8 x = *a; |
| 513 | uint8 y = *b; |
| 514 | if ('A' <= y && y <= 'Z') |
| 515 | y += 'a' - 'A'; |
| 516 | if (x != y) |
| 517 | return x - y; |
| 518 | } |
| 519 | return 0; |
| 520 | } |
| 521 | |
| 522 | |
| 523 | /***** Actual matching and rewriting code *****/ |
| 524 | |
| 525 | bool RE2::Match(const StringPiece& text, |
| 526 | int startpos, |
| 527 | int endpos, |
| 528 | Anchor re_anchor, |
| 529 | StringPiece* submatch, |
| 530 | int nsubmatch) const { |
| 531 | if (!ok() || suffix_regexp_ == NULL) { |
| 532 | if (options_.log_errors()) |
| 533 | LOG(ERROR) << "Invalid RE2: " << *error_; |
| 534 | return false; |
| 535 | } |
| 536 | |
| 537 | if (startpos < 0 || startpos > endpos || endpos > text.size()) { |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 538 | if (options_.log_errors()) |
| 539 | LOG(ERROR) << "RE2: invalid startpos, endpos pair."; |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 540 | return false; |
| 541 | } |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 542 | |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 543 | StringPiece subtext = text; |
| 544 | subtext.remove_prefix(startpos); |
| 545 | subtext.remove_suffix(text.size() - endpos); |
| 546 | |
| 547 | // Use DFAs to find exact location of match, filter out non-matches. |
| 548 | |
| 549 | // Don't ask for the location if we won't use it. |
| 550 | // SearchDFA can do extra optimizations in that case. |
| 551 | StringPiece match; |
| 552 | StringPiece* matchp = &match; |
| 553 | if (nsubmatch == 0) |
| 554 | matchp = NULL; |
| 555 | |
| 556 | int ncap = 1 + NumberOfCapturingGroups(); |
| 557 | if (ncap > nsubmatch) |
| 558 | ncap = nsubmatch; |
| 559 | |
| 560 | // If the regexp is anchored explicitly, must not be in middle of text. |
| 561 | if (prog_->anchor_start() && startpos != 0) |
| 562 | return false; |
| 563 | |
| 564 | // If the regexp is anchored explicitly, update re_anchor |
| 565 | // so that we can potentially fall into a faster case below. |
| 566 | if (prog_->anchor_start() && prog_->anchor_end()) |
| 567 | re_anchor = ANCHOR_BOTH; |
| 568 | else if (prog_->anchor_start() && re_anchor != ANCHOR_BOTH) |
| 569 | re_anchor = ANCHOR_START; |
| 570 | |
| 571 | // Check for the required prefix, if any. |
| 572 | int prefixlen = 0; |
| 573 | if (!prefix_.empty()) { |
| 574 | if (startpos != 0) |
| 575 | return false; |
| 576 | prefixlen = prefix_.size(); |
| 577 | if (prefixlen > subtext.size()) |
| 578 | return false; |
| 579 | if (prefix_foldcase_) { |
| 580 | if (ascii_strcasecmp(&prefix_[0], subtext.data(), prefixlen) != 0) |
| 581 | return false; |
| 582 | } else { |
| 583 | if (memcmp(&prefix_[0], subtext.data(), prefixlen) != 0) |
| 584 | return false; |
| 585 | } |
| 586 | subtext.remove_prefix(prefixlen); |
| 587 | // If there is a required prefix, the anchor must be at least ANCHOR_START. |
| 588 | if (re_anchor != ANCHOR_BOTH) |
| 589 | re_anchor = ANCHOR_START; |
| 590 | } |
| 591 | |
| 592 | Prog::Anchor anchor = Prog::kUnanchored; |
| 593 | Prog::MatchKind kind = Prog::kFirstMatch; |
| 594 | if (options_.longest_match()) |
| 595 | kind = Prog::kLongestMatch; |
| 596 | bool skipped_test = false; |
| 597 | |
| 598 | bool can_one_pass = (is_one_pass_ && ncap <= Prog::kMaxOnePassCapture); |
| 599 | |
| 600 | // SearchBitState allocates a bit vector of size prog_->size() * text.size(). |
| 601 | // It also allocates a stack of 3-word structures which could potentially |
| 602 | // grow as large as prog_->size() * text.size() but in practice is much |
| 603 | // smaller. |
| 604 | // Conditions for using SearchBitState: |
| 605 | const int MaxBitStateProg = 500; // prog_->size() <= Max. |
| 606 | const int MaxBitStateVector = 256*1024; // bit vector size <= Max (bits) |
| 607 | bool can_bit_state = prog_->size() <= MaxBitStateProg; |
| 608 | int bit_state_text_max = MaxBitStateVector / prog_->size(); |
| 609 | |
| 610 | bool dfa_failed = false; |
| 611 | switch (re_anchor) { |
| 612 | default: |
| 613 | case UNANCHORED: { |
| 614 | if (!prog_->SearchDFA(subtext, text, anchor, kind, |
| 615 | matchp, &dfa_failed, NULL)) { |
| 616 | if (dfa_failed) { |
| 617 | // Fall back to NFA below. |
| 618 | skipped_test = true; |
| 619 | if (FLAGS_trace_re2) |
| 620 | LOG(INFO) << "Match " << trunc(pattern_) |
| 621 | << " [" << CEscape(subtext) << "]" |
| 622 | << " DFA failed."; |
| 623 | break; |
| 624 | } |
| 625 | if (FLAGS_trace_re2) |
| 626 | LOG(INFO) << "Match " << trunc(pattern_) |
| 627 | << " [" << CEscape(subtext) << "]" |
| 628 | << " used DFA - no match."; |
| 629 | return false; |
| 630 | } |
| 631 | if (FLAGS_trace_re2) |
| 632 | LOG(INFO) << "Match " << trunc(pattern_) |
| 633 | << " [" << CEscape(subtext) << "]" |
| 634 | << " used DFA - match"; |
| 635 | if (matchp == NULL) // Matched. Don't care where |
| 636 | return true; |
| 637 | // SearchDFA set match[0].end() but didn't know where the |
| 638 | // match started. Run the regexp backward from match[0].end() |
| 639 | // to find the longest possible match -- that's where it started. |
| 640 | Prog* prog = ReverseProg(); |
| 641 | if (prog == NULL) |
| 642 | return false; |
| 643 | if (!prog->SearchDFA(match, text, Prog::kAnchored, |
| 644 | Prog::kLongestMatch, &match, &dfa_failed, NULL)) { |
| 645 | if (dfa_failed) { |
| 646 | // Fall back to NFA below. |
| 647 | skipped_test = true; |
| 648 | if (FLAGS_trace_re2) |
| 649 | LOG(INFO) << "Match " << trunc(pattern_) |
| 650 | << " [" << CEscape(subtext) << "]" |
| 651 | << " reverse DFA failed."; |
| 652 | break; |
| 653 | } |
| 654 | if (FLAGS_trace_re2) |
| 655 | LOG(INFO) << "Match " << trunc(pattern_) |
| 656 | << " [" << CEscape(subtext) << "]" |
| 657 | << " DFA inconsistency."; |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 658 | if (options_.log_errors()) |
| 659 | LOG(ERROR) << "DFA inconsistency"; |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 660 | return false; |
| 661 | } |
| 662 | if (FLAGS_trace_re2) |
| 663 | LOG(INFO) << "Match " << trunc(pattern_) |
| 664 | << " [" << CEscape(subtext) << "]" |
| 665 | << " used reverse DFA."; |
| 666 | break; |
| 667 | } |
| 668 | |
| 669 | case ANCHOR_BOTH: |
| 670 | case ANCHOR_START: |
| 671 | if (re_anchor == ANCHOR_BOTH) |
| 672 | kind = Prog::kFullMatch; |
| 673 | anchor = Prog::kAnchored; |
| 674 | |
| 675 | // If only a small amount of text and need submatch |
| 676 | // information anyway and we're going to use OnePass or BitState |
| 677 | // to get it, we might as well not even bother with the DFA: |
| 678 | // OnePass or BitState will be fast enough. |
| 679 | // On tiny texts, OnePass outruns even the DFA, and |
| 680 | // it doesn't have the shared state and occasional mutex that |
| 681 | // the DFA does. |
| 682 | if (can_one_pass && text.size() <= 4096 && |
| 683 | (ncap > 1 || text.size() <= 8)) { |
| 684 | if (FLAGS_trace_re2) |
| 685 | LOG(INFO) << "Match " << trunc(pattern_) |
| 686 | << " [" << CEscape(subtext) << "]" |
| 687 | << " skipping DFA for OnePass."; |
| 688 | skipped_test = true; |
| 689 | break; |
| 690 | } |
| 691 | if (can_bit_state && text.size() <= bit_state_text_max && ncap > 1) { |
| 692 | if (FLAGS_trace_re2) |
| 693 | LOG(INFO) << "Match " << trunc(pattern_) |
| 694 | << " [" << CEscape(subtext) << "]" |
| 695 | << " skipping DFA for BitState."; |
| 696 | skipped_test = true; |
| 697 | break; |
| 698 | } |
| 699 | if (!prog_->SearchDFA(subtext, text, anchor, kind, |
| 700 | &match, &dfa_failed, NULL)) { |
| 701 | if (dfa_failed) { |
| 702 | if (FLAGS_trace_re2) |
| 703 | LOG(INFO) << "Match " << trunc(pattern_) |
| 704 | << " [" << CEscape(subtext) << "]" |
| 705 | << " DFA failed."; |
| 706 | skipped_test = true; |
| 707 | break; |
| 708 | } |
| 709 | if (FLAGS_trace_re2) |
| 710 | LOG(INFO) << "Match " << trunc(pattern_) |
| 711 | << " [" << CEscape(subtext) << "]" |
| 712 | << " used DFA - no match."; |
| 713 | return false; |
| 714 | } |
| 715 | break; |
| 716 | } |
| 717 | |
| 718 | if (!skipped_test && ncap <= 1) { |
| 719 | // We know exactly where it matches. That's enough. |
| 720 | if (ncap == 1) |
| 721 | submatch[0] = match; |
| 722 | } else { |
| 723 | StringPiece subtext1; |
| 724 | if (skipped_test) { |
| 725 | // DFA ran out of memory or was skipped: |
| 726 | // need to search in entire original text. |
| 727 | subtext1 = subtext; |
| 728 | } else { |
| 729 | // DFA found the exact match location: |
| 730 | // let NFA run an anchored, full match search |
| 731 | // to find submatch locations. |
| 732 | subtext1 = match; |
| 733 | anchor = Prog::kAnchored; |
| 734 | kind = Prog::kFullMatch; |
| 735 | } |
| 736 | |
| 737 | if (can_one_pass && anchor != Prog::kUnanchored) { |
| 738 | if (FLAGS_trace_re2) |
| 739 | LOG(INFO) << "Match " << trunc(pattern_) |
| 740 | << " [" << CEscape(subtext) << "]" |
| 741 | << " using OnePass."; |
| 742 | if (!prog_->SearchOnePass(subtext1, text, anchor, kind, submatch, ncap)) { |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 743 | if (!skipped_test && options_.log_errors()) |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 744 | LOG(ERROR) << "SearchOnePass inconsistency"; |
| 745 | return false; |
| 746 | } |
| 747 | } else if (can_bit_state && subtext1.size() <= bit_state_text_max) { |
| 748 | if (FLAGS_trace_re2) |
| 749 | LOG(INFO) << "Match " << trunc(pattern_) |
| 750 | << " [" << CEscape(subtext) << "]" |
| 751 | << " using BitState."; |
| 752 | if (!prog_->SearchBitState(subtext1, text, anchor, |
| 753 | kind, submatch, ncap)) { |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 754 | if (!skipped_test && options_.log_errors()) |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 755 | LOG(ERROR) << "SearchBitState inconsistency"; |
| 756 | return false; |
| 757 | } |
| 758 | } else { |
| 759 | if (FLAGS_trace_re2) |
| 760 | LOG(INFO) << "Match " << trunc(pattern_) |
| 761 | << " [" << CEscape(subtext) << "]" |
| 762 | << " using NFA."; |
| 763 | if (!prog_->SearchNFA(subtext1, text, anchor, kind, submatch, ncap)) { |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 764 | if (!skipped_test && options_.log_errors()) |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 765 | LOG(ERROR) << "SearchNFA inconsistency"; |
| 766 | return false; |
| 767 | } |
| 768 | } |
| 769 | } |
| 770 | |
| 771 | // Adjust overall match for required prefix that we stripped off. |
| 772 | if (prefixlen > 0 && nsubmatch > 0) |
| 773 | submatch[0] = StringPiece(submatch[0].begin() - prefixlen, |
| 774 | submatch[0].size() + prefixlen); |
| 775 | |
| 776 | // Zero submatches that don't exist in the regexp. |
| 777 | for (int i = ncap; i < nsubmatch; i++) |
| 778 | submatch[i] = NULL; |
| 779 | return true; |
| 780 | } |
| 781 | |
| 782 | // Internal matcher - like Match() but takes Args not StringPieces. |
| 783 | bool RE2::DoMatch(const StringPiece& text, |
| 784 | Anchor anchor, |
| 785 | int* consumed, |
| 786 | const Arg* const* args, |
| 787 | int n) const { |
| 788 | if (!ok()) { |
| 789 | if (options_.log_errors()) |
| 790 | LOG(ERROR) << "Invalid RE2: " << *error_; |
| 791 | return false; |
| 792 | } |
| 793 | |
| 794 | // Count number of capture groups needed. |
| 795 | int nvec; |
| 796 | if (n == 0 && consumed == NULL) |
| 797 | nvec = 0; |
| 798 | else |
| 799 | nvec = n+1; |
| 800 | |
| 801 | StringPiece* vec; |
| 802 | StringPiece stkvec[kVecSize]; |
| 803 | StringPiece* heapvec = NULL; |
| 804 | |
| 805 | if (nvec <= arraysize(stkvec)) { |
| 806 | vec = stkvec; |
| 807 | } else { |
| 808 | vec = new StringPiece[nvec]; |
| 809 | heapvec = vec; |
| 810 | } |
| 811 | |
| 812 | if (!Match(text, 0, text.size(), anchor, vec, nvec)) { |
| 813 | delete[] heapvec; |
| 814 | return false; |
| 815 | } |
| 816 | |
| 817 | if(consumed != NULL) |
| 818 | *consumed = vec[0].end() - text.begin(); |
| 819 | |
| 820 | if (n == 0 || args == NULL) { |
| 821 | // We are not interested in results |
| 822 | delete[] heapvec; |
| 823 | return true; |
| 824 | } |
| 825 | |
| 826 | int ncap = NumberOfCapturingGroups(); |
| 827 | if (ncap < n) { |
| 828 | // RE has fewer capturing groups than number of arg pointers passed in |
| 829 | VLOG(1) << "Asked for " << n << " but only have " << ncap; |
| 830 | delete[] heapvec; |
| 831 | return false; |
| 832 | } |
| 833 | |
| 834 | // If we got here, we must have matched the whole pattern. |
| 835 | for (int i = 0; i < n; i++) { |
| 836 | const StringPiece& s = vec[i+1]; |
| 837 | if (!args[i]->Parse(s.data(), s.size())) { |
| 838 | // TODO: Should we indicate what the error was? |
| 839 | VLOG(1) << "Parse error on #" << i << " " << s << " " |
| 840 | << (void*)s.data() << "/" << s.size(); |
| 841 | delete[] heapvec; |
| 842 | return false; |
| 843 | } |
| 844 | } |
| 845 | |
| 846 | delete[] heapvec; |
| 847 | return true; |
| 848 | } |
| 849 | |
| 850 | // Append the "rewrite" string, with backslash subsitutions from "vec", |
| 851 | // to string "out". |
| 852 | bool RE2::Rewrite(string *out, const StringPiece &rewrite, |
| 853 | const StringPiece *vec, int veclen) const { |
| 854 | for (const char *s = rewrite.data(), *end = s + rewrite.size(); |
| 855 | s < end; s++) { |
| 856 | int c = *s; |
| 857 | if (c == '\\') { |
| 858 | s++; |
| 859 | c = (s < end) ? *s : -1; |
| 860 | if (isdigit(c)) { |
| 861 | int n = (c - '0'); |
| 862 | if (n >= veclen) { |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 863 | if (options_.log_errors()) { |
| 864 | LOG(ERROR) << "requested group " << n |
| 865 | << " in regexp " << rewrite.data(); |
| 866 | } |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 867 | return false; |
| 868 | } |
| 869 | StringPiece snip = vec[n]; |
| 870 | if (snip.size() > 0) |
| 871 | out->append(snip.data(), snip.size()); |
| 872 | } else if (c == '\\') { |
| 873 | out->push_back('\\'); |
| 874 | } else { |
Alexander Gutkin | 0d4c523 | 2013-02-28 13:47:27 +0000 | [diff] [blame] | 875 | if (options_.log_errors()) |
| 876 | LOG(ERROR) << "invalid rewrite pattern: " << rewrite.data(); |
Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 877 | return false; |
| 878 | } |
| 879 | } else { |
| 880 | out->push_back(c); |
| 881 | } |
| 882 | } |
| 883 | return true; |
| 884 | } |
| 885 | |
| 886 | // Return the number of capturing subpatterns, or -1 if the |
| 887 | // regexp wasn't valid on construction. |
| 888 | int RE2::NumberOfCapturingGroups() const { |
| 889 | if (suffix_regexp_ == NULL) |
| 890 | return -1; |
| 891 | ANNOTATE_BENIGN_RACE(&num_captures_, "benign race: in the worst case" |
| 892 | " multiple threads end up doing the same work in parallel."); |
| 893 | if (num_captures_ == -1) |
| 894 | num_captures_ = suffix_regexp_->NumCaptures(); |
| 895 | return num_captures_; |
| 896 | } |
| 897 | |
| 898 | // Checks that the rewrite string is well-formed with respect to this |
| 899 | // regular expression. |
| 900 | bool RE2::CheckRewriteString(const StringPiece& rewrite, string* error) const { |
| 901 | int max_token = -1; |
| 902 | for (const char *s = rewrite.data(), *end = s + rewrite.size(); |
| 903 | s < end; s++) { |
| 904 | int c = *s; |
| 905 | if (c != '\\') { |
| 906 | continue; |
| 907 | } |
| 908 | if (++s == end) { |
| 909 | *error = "Rewrite schema error: '\\' not allowed at end."; |
| 910 | return false; |
| 911 | } |
| 912 | c = *s; |
| 913 | if (c == '\\') { |
| 914 | continue; |
| 915 | } |
| 916 | if (!isdigit(c)) { |
| 917 | *error = "Rewrite schema error: " |
| 918 | "'\\' must be followed by a digit or '\\'."; |
| 919 | return false; |
| 920 | } |
| 921 | int n = (c - '0'); |
| 922 | if (max_token < n) { |
| 923 | max_token = n; |
| 924 | } |
| 925 | } |
| 926 | |
| 927 | if (max_token > NumberOfCapturingGroups()) { |
| 928 | SStringPrintf(error, "Rewrite schema requests %d matches, " |
| 929 | "but the regexp only has %d parenthesized subexpressions.", |
| 930 | max_token, NumberOfCapturingGroups()); |
| 931 | return false; |
| 932 | } |
| 933 | return true; |
| 934 | } |
| 935 | |
| 936 | /***** Parsers for various types *****/ |
| 937 | |
| 938 | bool RE2::Arg::parse_null(const char* str, int n, void* dest) { |
| 939 | // We fail if somebody asked us to store into a non-NULL void* pointer |
| 940 | return (dest == NULL); |
| 941 | } |
| 942 | |
| 943 | bool RE2::Arg::parse_string(const char* str, int n, void* dest) { |
| 944 | if (dest == NULL) return true; |
| 945 | reinterpret_cast<string*>(dest)->assign(str, n); |
| 946 | return true; |
| 947 | } |
| 948 | |
| 949 | bool RE2::Arg::parse_stringpiece(const char* str, int n, void* dest) { |
| 950 | if (dest == NULL) return true; |
| 951 | reinterpret_cast<StringPiece*>(dest)->set(str, n); |
| 952 | return true; |
| 953 | } |
| 954 | |
| 955 | bool RE2::Arg::parse_char(const char* str, int n, void* dest) { |
| 956 | if (n != 1) return false; |
| 957 | if (dest == NULL) return true; |
| 958 | *(reinterpret_cast<char*>(dest)) = str[0]; |
| 959 | return true; |
| 960 | } |
| 961 | |
| 962 | bool RE2::Arg::parse_uchar(const char* str, int n, void* dest) { |
| 963 | if (n != 1) return false; |
| 964 | if (dest == NULL) return true; |
| 965 | *(reinterpret_cast<unsigned char*>(dest)) = str[0]; |
| 966 | return true; |
| 967 | } |
| 968 | |
| 969 | // Largest number spec that we are willing to parse |
| 970 | static const int kMaxNumberLength = 32; |
| 971 | |
| 972 | // REQUIRES "buf" must have length at least kMaxNumberLength+1 |
| 973 | // Copies "str" into "buf" and null-terminates. |
| 974 | // Overwrites *np with the new length. |
| 975 | static const char* TerminateNumber(char* buf, const char* str, int* np) { |
| 976 | int n = *np; |
| 977 | if (n <= 0) return ""; |
| 978 | if (n > 0 && isspace(*str)) { |
| 979 | // We are less forgiving than the strtoxxx() routines and do not |
| 980 | // allow leading spaces. |
| 981 | return ""; |
| 982 | } |
| 983 | |
| 984 | // Although buf has a fixed maximum size, we can still handle |
| 985 | // arbitrarily large integers correctly by omitting leading zeros. |
| 986 | // (Numbers that are still too long will be out of range.) |
| 987 | // Before deciding whether str is too long, |
| 988 | // remove leading zeros with s/000+/00/. |
| 989 | // Leaving the leading two zeros in place means that |
| 990 | // we don't change 0000x123 (invalid) into 0x123 (valid). |
| 991 | // Skip over leading - before replacing. |
| 992 | bool neg = false; |
| 993 | if (n >= 1 && str[0] == '-') { |
| 994 | neg = true; |
| 995 | n--; |
| 996 | str++; |
| 997 | } |
| 998 | |
| 999 | if (n >= 3 && str[0] == '0' && str[1] == '0') { |
| 1000 | while (n >= 3 && str[2] == '0') { |
| 1001 | n--; |
| 1002 | str++; |
| 1003 | } |
| 1004 | } |
| 1005 | |
| 1006 | if (neg) { // make room in buf for - |
| 1007 | n++; |
| 1008 | str--; |
| 1009 | } |
| 1010 | |
| 1011 | if (n > kMaxNumberLength) return ""; |
| 1012 | |
| 1013 | memmove(buf, str, n); |
| 1014 | if (neg) { |
| 1015 | buf[0] = '-'; |
| 1016 | } |
| 1017 | buf[n] = '\0'; |
| 1018 | *np = n; |
| 1019 | return buf; |
| 1020 | } |
| 1021 | |
| 1022 | bool RE2::Arg::parse_long_radix(const char* str, |
| 1023 | int n, |
| 1024 | void* dest, |
| 1025 | int radix) { |
| 1026 | if (n == 0) return false; |
| 1027 | char buf[kMaxNumberLength+1]; |
| 1028 | str = TerminateNumber(buf, str, &n); |
| 1029 | char* end; |
| 1030 | errno = 0; |
| 1031 | long r = strtol(str, &end, radix); |
| 1032 | if (end != str + n) return false; // Leftover junk |
| 1033 | if (errno) return false; |
| 1034 | if (dest == NULL) return true; |
| 1035 | *(reinterpret_cast<long*>(dest)) = r; |
| 1036 | return true; |
| 1037 | } |
| 1038 | |
| 1039 | bool RE2::Arg::parse_ulong_radix(const char* str, |
| 1040 | int n, |
| 1041 | void* dest, |
| 1042 | int radix) { |
| 1043 | if (n == 0) return false; |
| 1044 | char buf[kMaxNumberLength+1]; |
| 1045 | str = TerminateNumber(buf, str, &n); |
| 1046 | if (str[0] == '-') { |
| 1047 | // strtoul() will silently accept negative numbers and parse |
| 1048 | // them. This module is more strict and treats them as errors. |
| 1049 | return false; |
| 1050 | } |
| 1051 | |
| 1052 | char* end; |
| 1053 | errno = 0; |
| 1054 | unsigned long r = strtoul(str, &end, radix); |
| 1055 | if (end != str + n) return false; // Leftover junk |
| 1056 | if (errno) return false; |
| 1057 | if (dest == NULL) return true; |
| 1058 | *(reinterpret_cast<unsigned long*>(dest)) = r; |
| 1059 | return true; |
| 1060 | } |
| 1061 | |
| 1062 | bool RE2::Arg::parse_short_radix(const char* str, |
| 1063 | int n, |
| 1064 | void* dest, |
| 1065 | int radix) { |
| 1066 | long r; |
| 1067 | if (!parse_long_radix(str, n, &r, radix)) return false; // Could not parse |
| 1068 | if ((short)r != r) return false; // Out of range |
| 1069 | if (dest == NULL) return true; |
| 1070 | *(reinterpret_cast<short*>(dest)) = r; |
| 1071 | return true; |
| 1072 | } |
| 1073 | |
| 1074 | bool RE2::Arg::parse_ushort_radix(const char* str, |
| 1075 | int n, |
| 1076 | void* dest, |
| 1077 | int radix) { |
| 1078 | unsigned long r; |
| 1079 | if (!parse_ulong_radix(str, n, &r, radix)) return false; // Could not parse |
| 1080 | if ((ushort)r != r) return false; // Out of range |
| 1081 | if (dest == NULL) return true; |
| 1082 | *(reinterpret_cast<unsigned short*>(dest)) = r; |
| 1083 | return true; |
| 1084 | } |
| 1085 | |
| 1086 | bool RE2::Arg::parse_int_radix(const char* str, |
| 1087 | int n, |
| 1088 | void* dest, |
| 1089 | int radix) { |
| 1090 | long r; |
| 1091 | if (!parse_long_radix(str, n, &r, radix)) return false; // Could not parse |
| 1092 | if ((int)r != r) return false; // Out of range |
| 1093 | if (dest == NULL) return true; |
| 1094 | *(reinterpret_cast<int*>(dest)) = r; |
| 1095 | return true; |
| 1096 | } |
| 1097 | |
| 1098 | bool RE2::Arg::parse_uint_radix(const char* str, |
| 1099 | int n, |
| 1100 | void* dest, |
| 1101 | int radix) { |
| 1102 | unsigned long r; |
| 1103 | if (!parse_ulong_radix(str, n, &r, radix)) return false; // Could not parse |
| 1104 | if ((uint)r != r) return false; // Out of range |
| 1105 | if (dest == NULL) return true; |
| 1106 | *(reinterpret_cast<unsigned int*>(dest)) = r; |
| 1107 | return true; |
| 1108 | } |
| 1109 | |
| 1110 | bool RE2::Arg::parse_longlong_radix(const char* str, |
| 1111 | int n, |
| 1112 | void* dest, |
| 1113 | int radix) { |
| 1114 | if (n == 0) return false; |
| 1115 | char buf[kMaxNumberLength+1]; |
| 1116 | str = TerminateNumber(buf, str, &n); |
| 1117 | char* end; |
| 1118 | errno = 0; |
| 1119 | int64 r = strtoll(str, &end, radix); |
| 1120 | if (end != str + n) return false; // Leftover junk |
| 1121 | if (errno) return false; |
| 1122 | if (dest == NULL) return true; |
| 1123 | *(reinterpret_cast<int64*>(dest)) = r; |
| 1124 | return true; |
| 1125 | } |
| 1126 | |
| 1127 | bool RE2::Arg::parse_ulonglong_radix(const char* str, |
| 1128 | int n, |
| 1129 | void* dest, |
| 1130 | int radix) { |
| 1131 | if (n == 0) return false; |
| 1132 | char buf[kMaxNumberLength+1]; |
| 1133 | str = TerminateNumber(buf, str, &n); |
| 1134 | if (str[0] == '-') { |
| 1135 | // strtoull() will silently accept negative numbers and parse |
| 1136 | // them. This module is more strict and treats them as errors. |
| 1137 | return false; |
| 1138 | } |
| 1139 | char* end; |
| 1140 | errno = 0; |
| 1141 | uint64 r = strtoull(str, &end, radix); |
| 1142 | if (end != str + n) return false; // Leftover junk |
| 1143 | if (errno) return false; |
| 1144 | if (dest == NULL) return true; |
| 1145 | *(reinterpret_cast<uint64*>(dest)) = r; |
| 1146 | return true; |
| 1147 | } |
| 1148 | |
| 1149 | static bool parse_double_float(const char* str, int n, bool isfloat, void *dest) { |
| 1150 | if (n == 0) return false; |
| 1151 | static const int kMaxLength = 200; |
| 1152 | char buf[kMaxLength]; |
| 1153 | if (n >= kMaxLength) return false; |
| 1154 | memcpy(buf, str, n); |
| 1155 | buf[n] = '\0'; |
| 1156 | errno = 0; |
| 1157 | char* end; |
| 1158 | double r; |
| 1159 | if (isfloat) { |
| 1160 | r = strtof(buf, &end); |
| 1161 | } else { |
| 1162 | r = strtod(buf, &end); |
| 1163 | } |
| 1164 | if (end != buf + n) return false; // Leftover junk |
| 1165 | if (errno) return false; |
| 1166 | if (dest == NULL) return true; |
| 1167 | if (isfloat) { |
| 1168 | *(reinterpret_cast<float*>(dest)) = r; |
| 1169 | } else { |
| 1170 | *(reinterpret_cast<double*>(dest)) = r; |
| 1171 | } |
| 1172 | return true; |
| 1173 | } |
| 1174 | |
| 1175 | bool RE2::Arg::parse_double(const char* str, int n, void* dest) { |
| 1176 | return parse_double_float(str, n, false, dest); |
| 1177 | } |
| 1178 | |
| 1179 | bool RE2::Arg::parse_float(const char* str, int n, void* dest) { |
| 1180 | return parse_double_float(str, n, true, dest); |
| 1181 | } |
| 1182 | |
| 1183 | |
| 1184 | #define DEFINE_INTEGER_PARSERS(name) \ |
| 1185 | bool RE2::Arg::parse_##name(const char* str, int n, void* dest) { \ |
| 1186 | return parse_##name##_radix(str, n, dest, 10); \ |
| 1187 | } \ |
| 1188 | bool RE2::Arg::parse_##name##_hex(const char* str, int n, void* dest) { \ |
| 1189 | return parse_##name##_radix(str, n, dest, 16); \ |
| 1190 | } \ |
| 1191 | bool RE2::Arg::parse_##name##_octal(const char* str, int n, void* dest) { \ |
| 1192 | return parse_##name##_radix(str, n, dest, 8); \ |
| 1193 | } \ |
| 1194 | bool RE2::Arg::parse_##name##_cradix(const char* str, int n, void* dest) { \ |
| 1195 | return parse_##name##_radix(str, n, dest, 0); \ |
| 1196 | } |
| 1197 | |
| 1198 | DEFINE_INTEGER_PARSERS(short); |
| 1199 | DEFINE_INTEGER_PARSERS(ushort); |
| 1200 | DEFINE_INTEGER_PARSERS(int); |
| 1201 | DEFINE_INTEGER_PARSERS(uint); |
| 1202 | DEFINE_INTEGER_PARSERS(long); |
| 1203 | DEFINE_INTEGER_PARSERS(ulong); |
| 1204 | DEFINE_INTEGER_PARSERS(longlong); |
| 1205 | DEFINE_INTEGER_PARSERS(ulonglong); |
| 1206 | |
| 1207 | #undef DEFINE_INTEGER_PARSERS |
| 1208 | |
| 1209 | } // namespace re2 |