Ian Hodson | 2ee91b4 | 2012-05-14 12:29:36 +0100 | [diff] [blame] | 1 | // Copyright 2003-2010 Google Inc. 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 | // This is a variant of PCRE's pcrecpp.h, originally written at Google. |
| 6 | // The main changes are the addition of the HitLimit method and |
| 7 | // compilation as PCRE in namespace re2. |
| 8 | |
| 9 | // C++ interface to the pcre regular-expression library. PCRE supports |
| 10 | // Perl-style regular expressions (with extensions like \d, \w, \s, |
| 11 | // ...). |
| 12 | // |
| 13 | // ----------------------------------------------------------------------- |
| 14 | // REGEXP SYNTAX: |
| 15 | // |
| 16 | // This module uses the pcre library and hence supports its syntax |
| 17 | // for regular expressions: |
| 18 | // |
| 19 | // http://www.google.com/search?q=pcre |
| 20 | // |
| 21 | // The syntax is pretty similar to Perl's. For those not familiar |
| 22 | // with Perl's regular expressions, here are some examples of the most |
| 23 | // commonly used extensions: |
| 24 | // |
| 25 | // "hello (\\w+) world" -- \w matches a "word" character |
| 26 | // "version (\\d+)" -- \d matches a digit |
| 27 | // "hello\\s+world" -- \s matches any whitespace character |
| 28 | // "\\b(\\w+)\\b" -- \b matches empty string at a word boundary |
| 29 | // "(?i)hello" -- (?i) turns on case-insensitive matching |
| 30 | // "/\\*(.*?)\\*/" -- .*? matches . minimum no. of times possible |
| 31 | // |
| 32 | // ----------------------------------------------------------------------- |
| 33 | // MATCHING INTERFACE: |
| 34 | // |
| 35 | // The "FullMatch" operation checks that supplied text matches a |
| 36 | // supplied pattern exactly. |
| 37 | // |
| 38 | // Example: successful match |
| 39 | // CHECK(PCRE::FullMatch("hello", "h.*o")); |
| 40 | // |
| 41 | // Example: unsuccessful match (requires full match): |
| 42 | // CHECK(!PCRE::FullMatch("hello", "e")); |
| 43 | // |
| 44 | // ----------------------------------------------------------------------- |
| 45 | // UTF-8 AND THE MATCHING INTERFACE: |
| 46 | // |
| 47 | // By default, pattern and text are plain text, one byte per character. |
| 48 | // The UTF8 flag, passed to the constructor, causes both pattern |
| 49 | // and string to be treated as UTF-8 text, still a byte stream but |
| 50 | // potentially multiple bytes per character. In practice, the text |
| 51 | // is likelier to be UTF-8 than the pattern, but the match returned |
| 52 | // may depend on the UTF8 flag, so always use it when matching |
| 53 | // UTF8 text. E.g., "." will match one byte normally but with UTF8 |
| 54 | // set may match up to three bytes of a multi-byte character. |
| 55 | // |
| 56 | // Example: |
| 57 | // PCRE re(utf8_pattern, PCRE::UTF8); |
| 58 | // CHECK(PCRE::FullMatch(utf8_string, re)); |
| 59 | // |
| 60 | // ----------------------------------------------------------------------- |
| 61 | // MATCHING WITH SUB-STRING EXTRACTION: |
| 62 | // |
| 63 | // You can supply extra pointer arguments to extract matched subpieces. |
| 64 | // |
| 65 | // Example: extracts "ruby" into "s" and 1234 into "i" |
| 66 | // int i; |
| 67 | // string s; |
| 68 | // CHECK(PCRE::FullMatch("ruby:1234", "(\\w+):(\\d+)", &s, &i)); |
| 69 | // |
| 70 | // Example: fails because string cannot be stored in integer |
| 71 | // CHECK(!PCRE::FullMatch("ruby", "(.*)", &i)); |
| 72 | // |
| 73 | // Example: fails because there aren't enough sub-patterns: |
| 74 | // CHECK(!PCRE::FullMatch("ruby:1234", "\\w+:\\d+", &s)); |
| 75 | // |
| 76 | // Example: does not try to extract any extra sub-patterns |
| 77 | // CHECK(PCRE::FullMatch("ruby:1234", "(\\w+):(\\d+)", &s)); |
| 78 | // |
| 79 | // Example: does not try to extract into NULL |
| 80 | // CHECK(PCRE::FullMatch("ruby:1234", "(\\w+):(\\d+)", NULL, &i)); |
| 81 | // |
| 82 | // Example: integer overflow causes failure |
| 83 | // CHECK(!PCRE::FullMatch("ruby:1234567891234", "\\w+:(\\d+)", &i)); |
| 84 | // |
| 85 | // ----------------------------------------------------------------------- |
| 86 | // PARTIAL MATCHES |
| 87 | // |
| 88 | // You can use the "PartialMatch" operation when you want the pattern |
| 89 | // to match any substring of the text. |
| 90 | // |
| 91 | // Example: simple search for a string: |
| 92 | // CHECK(PCRE::PartialMatch("hello", "ell")); |
| 93 | // |
| 94 | // Example: find first number in a string |
| 95 | // int number; |
| 96 | // CHECK(PCRE::PartialMatch("x*100 + 20", "(\\d+)", &number)); |
| 97 | // CHECK_EQ(number, 100); |
| 98 | // |
| 99 | // ----------------------------------------------------------------------- |
| 100 | // PPCRE-COMPILED PCREGULAR EXPPCRESSIONS |
| 101 | // |
| 102 | // PCRE makes it easy to use any string as a regular expression, without |
| 103 | // requiring a separate compilation step. |
| 104 | // |
| 105 | // If speed is of the essence, you can create a pre-compiled "PCRE" |
| 106 | // object from the pattern and use it multiple times. If you do so, |
| 107 | // you can typically parse text faster than with sscanf. |
| 108 | // |
| 109 | // Example: precompile pattern for faster matching: |
| 110 | // PCRE pattern("h.*o"); |
| 111 | // while (ReadLine(&str)) { |
| 112 | // if (PCRE::FullMatch(str, pattern)) ...; |
| 113 | // } |
| 114 | // |
| 115 | // ----------------------------------------------------------------------- |
| 116 | // SCANNING TEXT INCPCREMENTALLY |
| 117 | // |
| 118 | // The "Consume" operation may be useful if you want to repeatedly |
| 119 | // match regular expressions at the front of a string and skip over |
| 120 | // them as they match. This requires use of the "StringPiece" type, |
| 121 | // which represents a sub-range of a real string. |
| 122 | // |
| 123 | // Example: read lines of the form "var = value" from a string. |
| 124 | // string contents = ...; // Fill string somehow |
| 125 | // StringPiece input(contents); // Wrap a StringPiece around it |
| 126 | // |
| 127 | // string var; |
| 128 | // int value; |
| 129 | // while (PCRE::Consume(&input, "(\\w+) = (\\d+)\n", &var, &value)) { |
| 130 | // ...; |
| 131 | // } |
| 132 | // |
| 133 | // Each successful call to "Consume" will set "var/value", and also |
| 134 | // advance "input" so it points past the matched text. Note that if the |
| 135 | // regular expression matches an empty string, input will advance |
| 136 | // by 0 bytes. If the regular expression being used might match |
| 137 | // an empty string, the loop body must check for this case and either |
| 138 | // advance the string or break out of the loop. |
| 139 | // |
| 140 | // The "FindAndConsume" operation is similar to "Consume" but does not |
| 141 | // anchor your match at the beginning of the string. For example, you |
| 142 | // could extract all words from a string by repeatedly calling |
| 143 | // PCRE::FindAndConsume(&input, "(\\w+)", &word) |
| 144 | // |
| 145 | // ----------------------------------------------------------------------- |
| 146 | // PARSING HEX/OCTAL/C-RADIX NUMBERS |
| 147 | // |
| 148 | // By default, if you pass a pointer to a numeric value, the |
| 149 | // corresponding text is interpreted as a base-10 number. You can |
| 150 | // instead wrap the pointer with a call to one of the operators Hex(), |
| 151 | // Octal(), or CRadix() to interpret the text in another base. The |
| 152 | // CRadix operator interprets C-style "0" (base-8) and "0x" (base-16) |
| 153 | // prefixes, but defaults to base-10. |
| 154 | // |
| 155 | // Example: |
| 156 | // int a, b, c, d; |
| 157 | // CHECK(PCRE::FullMatch("100 40 0100 0x40", "(.*) (.*) (.*) (.*)", |
| 158 | // Octal(&a), Hex(&b), CRadix(&c), CRadix(&d)); |
| 159 | // will leave 64 in a, b, c, and d. |
| 160 | |
| 161 | #include "util/util.h" |
| 162 | #include "re2/stringpiece.h" |
| 163 | |
| 164 | #ifdef USEPCRE |
| 165 | #include <pcre.h> |
| 166 | namespace re2 { |
| 167 | const bool UsingPCRE = true; |
| 168 | } // namespace re2 |
| 169 | #else |
| 170 | namespace re2 { |
| 171 | const bool UsingPCRE = false; |
| 172 | struct pcre; |
| 173 | struct pcre_extra { int flags, match_limit, match_limit_recursion; }; |
| 174 | #define pcre_free(x) {} |
| 175 | #define PCRE_EXTRA_MATCH_LIMIT 0 |
| 176 | #define PCRE_EXTRA_MATCH_LIMIT_RECURSION 0 |
| 177 | #define PCRE_ANCHORED 0 |
| 178 | #define PCRE_NOTEMPTY 0 |
| 179 | #define PCRE_ERROR_NOMATCH 1 |
| 180 | #define PCRE_ERROR_MATCHLIMIT 2 |
| 181 | #define PCRE_ERROR_RECURSIONLIMIT 3 |
| 182 | #define PCRE_INFO_CAPTURECOUNT 0 |
| 183 | #define pcre_compile(a,b,c,d,e) ({ (void)(a); (void)(b); *(c)=""; *(d)=0; (void)(e); ((pcre*)0); }) |
| 184 | #define pcre_exec(a, b, c, d, e, f, g, h) ({ (void)(a); (void)(b); (void)(c); (void)(d); (void)(e); (void)(f); (void)(g); (void)(h); 0; }) |
| 185 | #define pcre_fullinfo(a, b, c, d) ({ (void)(a); (void)(b); (void)(c); *(d) = 0; 0; }) |
| 186 | } // namespace re2 |
| 187 | #endif |
| 188 | |
| 189 | namespace re2 { |
| 190 | |
| 191 | class PCRE_Options; |
| 192 | |
| 193 | // Interface for regular expression matching. Also corresponds to a |
| 194 | // pre-compiled regular expression. An "PCRE" object is safe for |
| 195 | // concurrent use by multiple threads. |
| 196 | class PCRE { |
| 197 | public: |
| 198 | // We convert user-passed pointers into special Arg objects |
| 199 | class Arg; |
| 200 | |
| 201 | // Marks end of arg list. |
| 202 | // ONLY USE IN OPTIONAL ARG DEFAULTS. |
| 203 | // DO NOT PASS EXPLICITLY. |
| 204 | static Arg no_more_args; |
| 205 | |
| 206 | // Options are same value as those in pcre. We provide them here |
| 207 | // to avoid users needing to include pcre.h and also to isolate |
| 208 | // users from pcre should we change the underlying library. |
| 209 | // Only those needed by Google programs are exposed here to |
| 210 | // avoid collision with options employed internally by regexp.cc |
| 211 | // Note that some options have equivalents that can be specified in |
| 212 | // the regexp itself. For example, prefixing your regexp with |
| 213 | // "(?s)" has the same effect as the PCRE_DOTALL option. |
| 214 | enum Option { |
| 215 | None = 0x0000, |
| 216 | UTF8 = 0x0800, // == PCRE_UTF8 |
| 217 | EnabledCompileOptions = UTF8, |
| 218 | EnabledExecOptions = 0x0000, // TODO: use to replace anchor flag |
| 219 | }; |
| 220 | |
| 221 | // We provide implicit conversions from strings so that users can |
| 222 | // pass in a string or a "const char*" wherever an "PCRE" is expected. |
| 223 | PCRE(const char* pattern); |
| 224 | PCRE(const char* pattern, Option option); |
| 225 | PCRE(const string& pattern); |
| 226 | PCRE(const string& pattern, Option option); |
| 227 | PCRE(const char *pattern, const PCRE_Options& re_option); |
| 228 | PCRE(const string& pattern, const PCRE_Options& re_option); |
| 229 | |
| 230 | ~PCRE(); |
| 231 | |
| 232 | // The string specification for this PCRE. E.g. |
| 233 | // PCRE re("ab*c?d+"); |
| 234 | // re.pattern(); // "ab*c?d+" |
| 235 | const string& pattern() const { return pattern_; } |
| 236 | |
| 237 | // If PCRE could not be created properly, returns an error string. |
| 238 | // Else returns the empty string. |
| 239 | const string& error() const { return *error_; } |
| 240 | |
| 241 | // Whether the PCRE has hit a match limit during execution. |
| 242 | // Not thread safe. Intended only for testing. |
| 243 | // If hitting match limits is a problem, |
| 244 | // you should be using PCRE2 (re2/re2.h) |
| 245 | // instead of checking this flag. |
| 246 | bool HitLimit(); |
| 247 | void ClearHitLimit(); |
| 248 | |
| 249 | /***** The useful part: the matching interface *****/ |
| 250 | |
| 251 | // Matches "text" against "pattern". If pointer arguments are |
| 252 | // supplied, copies matched sub-patterns into them. |
| 253 | // |
| 254 | // You can pass in a "const char*" or a "string" for "text". |
| 255 | // You can pass in a "const char*" or a "string" or a "PCRE" for "pattern". |
| 256 | // |
| 257 | // The provided pointer arguments can be pointers to any scalar numeric |
| 258 | // type, or one of: |
| 259 | // string (matched piece is copied to string) |
| 260 | // StringPiece (StringPiece is mutated to point to matched piece) |
| 261 | // T (where "bool T::ParseFrom(const char*, int)" exists) |
| 262 | // (void*)NULL (the corresponding matched sub-pattern is not copied) |
| 263 | // |
| 264 | // Returns true iff all of the following conditions are satisfied: |
| 265 | // a. "text" matches "pattern" exactly |
| 266 | // b. The number of matched sub-patterns is >= number of supplied pointers |
| 267 | // c. The "i"th argument has a suitable type for holding the |
| 268 | // string captured as the "i"th sub-pattern. If you pass in |
| 269 | // NULL for the "i"th argument, or pass fewer arguments than |
| 270 | // number of sub-patterns, "i"th captured sub-pattern is |
| 271 | // ignored. |
| 272 | // |
| 273 | // CAVEAT: An optional sub-pattern that does not exist in the |
| 274 | // matched string is assigned the empty string. Therefore, the |
| 275 | // following will return false (because the empty string is not a |
| 276 | // valid number): |
| 277 | // int number; |
| 278 | // PCRE::FullMatch("abc", "[a-z]+(\\d+)?", &number); |
| 279 | struct FullMatchFunctor { |
| 280 | bool operator ()(const StringPiece& text, const PCRE& re, // 3..16 args |
| 281 | const Arg& ptr1 = no_more_args, |
| 282 | const Arg& ptr2 = no_more_args, |
| 283 | const Arg& ptr3 = no_more_args, |
| 284 | const Arg& ptr4 = no_more_args, |
| 285 | const Arg& ptr5 = no_more_args, |
| 286 | const Arg& ptr6 = no_more_args, |
| 287 | const Arg& ptr7 = no_more_args, |
| 288 | const Arg& ptr8 = no_more_args, |
| 289 | const Arg& ptr9 = no_more_args, |
| 290 | const Arg& ptr10 = no_more_args, |
| 291 | const Arg& ptr11 = no_more_args, |
| 292 | const Arg& ptr12 = no_more_args, |
| 293 | const Arg& ptr13 = no_more_args, |
| 294 | const Arg& ptr14 = no_more_args, |
| 295 | const Arg& ptr15 = no_more_args, |
| 296 | const Arg& ptr16 = no_more_args) const; |
| 297 | }; |
| 298 | |
| 299 | static const FullMatchFunctor FullMatch; |
| 300 | |
| 301 | // Exactly like FullMatch(), except that "pattern" is allowed to match |
| 302 | // a substring of "text". |
| 303 | struct PartialMatchFunctor { |
| 304 | bool operator ()(const StringPiece& text, const PCRE& re, // 3..16 args |
| 305 | const Arg& ptr1 = no_more_args, |
| 306 | const Arg& ptr2 = no_more_args, |
| 307 | const Arg& ptr3 = no_more_args, |
| 308 | const Arg& ptr4 = no_more_args, |
| 309 | const Arg& ptr5 = no_more_args, |
| 310 | const Arg& ptr6 = no_more_args, |
| 311 | const Arg& ptr7 = no_more_args, |
| 312 | const Arg& ptr8 = no_more_args, |
| 313 | const Arg& ptr9 = no_more_args, |
| 314 | const Arg& ptr10 = no_more_args, |
| 315 | const Arg& ptr11 = no_more_args, |
| 316 | const Arg& ptr12 = no_more_args, |
| 317 | const Arg& ptr13 = no_more_args, |
| 318 | const Arg& ptr14 = no_more_args, |
| 319 | const Arg& ptr15 = no_more_args, |
| 320 | const Arg& ptr16 = no_more_args) const; |
| 321 | }; |
| 322 | |
| 323 | static const PartialMatchFunctor PartialMatch; |
| 324 | |
| 325 | // Like FullMatch() and PartialMatch(), except that pattern has to |
| 326 | // match a prefix of "text", and "input" is advanced past the matched |
| 327 | // text. Note: "input" is modified iff this routine returns true. |
| 328 | struct ConsumeFunctor { |
| 329 | bool operator ()(StringPiece* input, const PCRE& pattern, // 3..16 args |
| 330 | const Arg& ptr1 = no_more_args, |
| 331 | const Arg& ptr2 = no_more_args, |
| 332 | const Arg& ptr3 = no_more_args, |
| 333 | const Arg& ptr4 = no_more_args, |
| 334 | const Arg& ptr5 = no_more_args, |
| 335 | const Arg& ptr6 = no_more_args, |
| 336 | const Arg& ptr7 = no_more_args, |
| 337 | const Arg& ptr8 = no_more_args, |
| 338 | const Arg& ptr9 = no_more_args, |
| 339 | const Arg& ptr10 = no_more_args, |
| 340 | const Arg& ptr11 = no_more_args, |
| 341 | const Arg& ptr12 = no_more_args, |
| 342 | const Arg& ptr13 = no_more_args, |
| 343 | const Arg& ptr14 = no_more_args, |
| 344 | const Arg& ptr15 = no_more_args, |
| 345 | const Arg& ptr16 = no_more_args) const; |
| 346 | }; |
| 347 | |
| 348 | static const ConsumeFunctor Consume; |
| 349 | |
| 350 | // Like Consume(..), but does not anchor the match at the beginning of the |
| 351 | // string. That is, "pattern" need not start its match at the beginning of |
| 352 | // "input". For example, "FindAndConsume(s, "(\\w+)", &word)" finds the next |
| 353 | // word in "s" and stores it in "word". |
| 354 | struct FindAndConsumeFunctor { |
| 355 | bool operator ()(StringPiece* input, const PCRE& pattern, |
| 356 | const Arg& ptr1 = no_more_args, |
| 357 | const Arg& ptr2 = no_more_args, |
| 358 | const Arg& ptr3 = no_more_args, |
| 359 | const Arg& ptr4 = no_more_args, |
| 360 | const Arg& ptr5 = no_more_args, |
| 361 | const Arg& ptr6 = no_more_args, |
| 362 | const Arg& ptr7 = no_more_args, |
| 363 | const Arg& ptr8 = no_more_args, |
| 364 | const Arg& ptr9 = no_more_args, |
| 365 | const Arg& ptr10 = no_more_args, |
| 366 | const Arg& ptr11 = no_more_args, |
| 367 | const Arg& ptr12 = no_more_args, |
| 368 | const Arg& ptr13 = no_more_args, |
| 369 | const Arg& ptr14 = no_more_args, |
| 370 | const Arg& ptr15 = no_more_args, |
| 371 | const Arg& ptr16 = no_more_args) const; |
| 372 | }; |
| 373 | |
| 374 | static const FindAndConsumeFunctor FindAndConsume; |
| 375 | |
| 376 | // Replace the first match of "pattern" in "str" with "rewrite". |
| 377 | // Within "rewrite", backslash-escaped digits (\1 to \9) can be |
| 378 | // used to insert text matching corresponding parenthesized group |
| 379 | // from the pattern. \0 in "rewrite" refers to the entire matching |
| 380 | // text. E.g., |
| 381 | // |
| 382 | // string s = "yabba dabba doo"; |
| 383 | // CHECK(PCRE::Replace(&s, "b+", "d")); |
| 384 | // |
| 385 | // will leave "s" containing "yada dabba doo" |
| 386 | // |
| 387 | // Returns true if the pattern matches and a replacement occurs, |
| 388 | // false otherwise. |
| 389 | static bool Replace(string *str, |
| 390 | const PCRE& pattern, |
| 391 | const StringPiece& rewrite); |
| 392 | |
| 393 | // Like Replace(), except replaces all occurrences of the pattern in |
| 394 | // the string with the rewrite. Replacements are not subject to |
| 395 | // re-matching. E.g., |
| 396 | // |
| 397 | // string s = "yabba dabba doo"; |
| 398 | // CHECK(PCRE::GlobalReplace(&s, "b+", "d")); |
| 399 | // |
| 400 | // will leave "s" containing "yada dada doo" |
| 401 | // |
| 402 | // Returns the number of replacements made. |
| 403 | static int GlobalReplace(string *str, |
| 404 | const PCRE& pattern, |
| 405 | const StringPiece& rewrite); |
| 406 | |
| 407 | // Like Replace, except that if the pattern matches, "rewrite" |
| 408 | // is copied into "out" with substitutions. The non-matching |
| 409 | // portions of "text" are ignored. |
| 410 | // |
| 411 | // Returns true iff a match occurred and the extraction happened |
| 412 | // successfully; if no match occurs, the string is left unaffected. |
| 413 | static bool Extract(const StringPiece &text, |
| 414 | const PCRE& pattern, |
| 415 | const StringPiece &rewrite, |
| 416 | string *out); |
| 417 | |
| 418 | // Check that the given @p rewrite string is suitable for use with |
| 419 | // this PCRE. It checks that: |
| 420 | // * The PCRE has enough parenthesized subexpressions to satisfy all |
| 421 | // of the \N tokens in @p rewrite, and |
| 422 | // * The @p rewrite string doesn't have any syntax errors |
| 423 | // ('\' followed by anything besides [0-9] and '\'). |
| 424 | // Making this test will guarantee that "replace" and "extract" |
| 425 | // operations won't LOG(ERROR) or fail because of a bad rewrite |
| 426 | // string. |
| 427 | // @param rewrite The proposed rewrite string. |
| 428 | // @param error An error message is recorded here, iff we return false. |
| 429 | // Otherwise, it is unchanged. |
| 430 | // @return true, iff @p rewrite is suitable for use with the PCRE. |
| 431 | bool CheckRewriteString(const StringPiece& rewrite, string* error) const; |
| 432 | |
| 433 | // Returns a copy of 'unquoted' with all potentially meaningful |
| 434 | // regexp characters backslash-escaped. The returned string, used |
| 435 | // as a regular expression, will exactly match the original string. |
| 436 | // For example, |
| 437 | // 1.5-2.0? |
| 438 | // becomes: |
| 439 | // 1\.5\-2\.0\? |
| 440 | static string QuoteMeta(const StringPiece& unquoted); |
| 441 | |
| 442 | /***** Generic matching interface (not so nice to use) *****/ |
| 443 | |
| 444 | // Type of match (TODO: Should be restructured as an Option) |
| 445 | enum Anchor { |
| 446 | UNANCHORED, // No anchoring |
| 447 | ANCHOR_START, // Anchor at start only |
| 448 | ANCHOR_BOTH, // Anchor at start and end |
| 449 | }; |
| 450 | |
| 451 | // General matching routine. Stores the length of the match in |
| 452 | // "*consumed" if successful. |
| 453 | bool DoMatch(const StringPiece& text, |
| 454 | Anchor anchor, |
| 455 | int* consumed, |
| 456 | const Arg* const* args, int n) const; |
| 457 | |
| 458 | // Return the number of capturing subpatterns, or -1 if the |
| 459 | // regexp wasn't valid on construction. |
| 460 | int NumberOfCapturingGroups() const; |
| 461 | |
| 462 | private: |
| 463 | void Init(const char* pattern, Option option, int match_limit, |
| 464 | int stack_limit, bool report_errors); |
| 465 | |
| 466 | // Match against "text", filling in "vec" (up to "vecsize" * 2/3) with |
| 467 | // pairs of integers for the beginning and end positions of matched |
| 468 | // text. The first pair corresponds to the entire matched text; |
| 469 | // subsequent pairs correspond, in order, to parentheses-captured |
| 470 | // matches. Returns the number of pairs (one more than the number of |
| 471 | // the last subpattern with a match) if matching was successful |
| 472 | // and zero if the match failed. |
| 473 | // I.e. for PCRE("(foo)|(bar)|(baz)") it will return 2, 3, and 4 when matching |
| 474 | // against "foo", "bar", and "baz" respectively. |
| 475 | // When matching PCRE("(foo)|hello") against "hello", it will return 1. |
| 476 | // But the values for all subpattern are filled in into "vec". |
| 477 | int TryMatch(const StringPiece& text, |
| 478 | int startpos, |
| 479 | Anchor anchor, |
| 480 | bool empty_ok, |
| 481 | int *vec, |
| 482 | int vecsize) const; |
| 483 | |
| 484 | // Append the "rewrite" string, with backslash subsitutions from "text" |
| 485 | // and "vec", to string "out". |
| 486 | bool Rewrite(string *out, |
| 487 | const StringPiece &rewrite, |
| 488 | const StringPiece &text, |
| 489 | int *vec, |
| 490 | int veclen) const; |
| 491 | |
| 492 | // internal implementation for DoMatch |
| 493 | bool DoMatchImpl(const StringPiece& text, |
| 494 | Anchor anchor, |
| 495 | int* consumed, |
| 496 | const Arg* const args[], |
| 497 | int n, |
| 498 | int* vec, |
| 499 | int vecsize) const; |
| 500 | |
| 501 | // Compile the regexp for the specified anchoring mode |
| 502 | pcre* Compile(Anchor anchor); |
| 503 | |
| 504 | string pattern_; |
| 505 | Option options_; |
| 506 | pcre* re_full_; // For full matches |
| 507 | pcre* re_partial_; // For partial matches |
| 508 | const string* error_; // Error indicator (or empty string) |
| 509 | bool report_errors_; // Silences error logging if false |
| 510 | int match_limit_; // Limit on execution resources |
| 511 | int stack_limit_; // Limit on stack resources (bytes) |
| 512 | mutable int32_t hit_limit_; // Hit limit during execution (bool)? |
| 513 | DISALLOW_EVIL_CONSTRUCTORS(PCRE); |
| 514 | }; |
| 515 | |
| 516 | // PCRE_Options allow you to set the PCRE::Options, plus any pcre |
| 517 | // "extra" options. The only extras are match_limit, which limits |
| 518 | // the CPU time of a match, and stack_limit, which limits the |
| 519 | // stack usage. Setting a limit to <= 0 lets PCRE pick a sensible default |
| 520 | // that should not cause too many problems in production code. |
| 521 | // If PCRE hits a limit during a match, it may return a false negative, |
| 522 | // but (hopefully) it won't crash. |
| 523 | // |
| 524 | // NOTE: If you are handling regular expressions specified by |
| 525 | // (external or internal) users, rather than hard-coded ones, |
| 526 | // you should be using PCRE2, which uses an alternate implementation |
| 527 | // that avoids these issues. See http://go/re2quick. |
| 528 | class PCRE_Options { |
| 529 | public: |
| 530 | // constructor |
| 531 | PCRE_Options() : option_(PCRE::None), match_limit_(0), stack_limit_(0), report_errors_(true) {} |
| 532 | // accessors |
| 533 | PCRE::Option option() const { return option_; } |
| 534 | void set_option(PCRE::Option option) { |
| 535 | option_ = option; |
| 536 | } |
| 537 | int match_limit() const { return match_limit_; } |
| 538 | void set_match_limit(int match_limit) { |
| 539 | match_limit_ = match_limit; |
| 540 | } |
| 541 | int stack_limit() const { return stack_limit_; } |
| 542 | void set_stack_limit(int stack_limit) { |
| 543 | stack_limit_ = stack_limit; |
| 544 | } |
| 545 | |
| 546 | // If the regular expression is malformed, an error message will be printed |
| 547 | // iff report_errors() is true. Default: true. |
| 548 | bool report_errors() const { return report_errors_; } |
| 549 | void set_report_errors(bool report_errors) { |
| 550 | report_errors_ = report_errors; |
| 551 | } |
| 552 | private: |
| 553 | PCRE::Option option_; |
| 554 | int match_limit_; |
| 555 | int stack_limit_; |
| 556 | bool report_errors_; |
| 557 | }; |
| 558 | |
| 559 | |
| 560 | /***** Implementation details *****/ |
| 561 | |
| 562 | // Hex/Octal/Binary? |
| 563 | |
| 564 | // Special class for parsing into objects that define a ParseFrom() method |
| 565 | template <class T> |
| 566 | class _PCRE_MatchObject { |
| 567 | public: |
| 568 | static inline bool Parse(const char* str, int n, void* dest) { |
| 569 | if (dest == NULL) return true; |
| 570 | T* object = reinterpret_cast<T*>(dest); |
| 571 | return object->ParseFrom(str, n); |
| 572 | } |
| 573 | }; |
| 574 | |
| 575 | class PCRE::Arg { |
| 576 | public: |
| 577 | // Empty constructor so we can declare arrays of PCRE::Arg |
| 578 | Arg(); |
| 579 | |
| 580 | // Constructor specially designed for NULL arguments |
| 581 | Arg(void*); |
| 582 | |
| 583 | typedef bool (*Parser)(const char* str, int n, void* dest); |
| 584 | |
| 585 | // Type-specific parsers |
| 586 | #define MAKE_PARSER(type,name) \ |
| 587 | Arg(type* p) : arg_(p), parser_(name) { } \ |
| 588 | Arg(type* p, Parser parser) : arg_(p), parser_(parser) { } \ |
| 589 | |
| 590 | |
| 591 | MAKE_PARSER(char, parse_char); |
| 592 | MAKE_PARSER(unsigned char, parse_uchar); |
| 593 | MAKE_PARSER(short, parse_short); |
| 594 | MAKE_PARSER(unsigned short, parse_ushort); |
| 595 | MAKE_PARSER(int, parse_int); |
| 596 | MAKE_PARSER(unsigned int, parse_uint); |
| 597 | MAKE_PARSER(long, parse_long); |
| 598 | MAKE_PARSER(unsigned long, parse_ulong); |
| 599 | MAKE_PARSER(long long, parse_longlong); |
| 600 | MAKE_PARSER(unsigned long long, parse_ulonglong); |
| 601 | MAKE_PARSER(float, parse_float); |
| 602 | MAKE_PARSER(double, parse_double); |
| 603 | MAKE_PARSER(string, parse_string); |
| 604 | MAKE_PARSER(StringPiece, parse_stringpiece); |
| 605 | |
| 606 | #undef MAKE_PARSER |
| 607 | |
| 608 | // Generic constructor |
| 609 | template <class T> Arg(T*, Parser parser); |
| 610 | // Generic constructor template |
| 611 | template <class T> Arg(T* p) |
| 612 | : arg_(p), parser_(_PCRE_MatchObject<T>::Parse) { |
| 613 | } |
| 614 | |
| 615 | // Parse the data |
| 616 | bool Parse(const char* str, int n) const; |
| 617 | |
| 618 | private: |
| 619 | void* arg_; |
| 620 | Parser parser_; |
| 621 | |
| 622 | static bool parse_null (const char* str, int n, void* dest); |
| 623 | static bool parse_char (const char* str, int n, void* dest); |
| 624 | static bool parse_uchar (const char* str, int n, void* dest); |
| 625 | static bool parse_float (const char* str, int n, void* dest); |
| 626 | static bool parse_double (const char* str, int n, void* dest); |
| 627 | static bool parse_string (const char* str, int n, void* dest); |
| 628 | static bool parse_stringpiece (const char* str, int n, void* dest); |
| 629 | |
| 630 | #define DECLARE_INTEGER_PARSER(name) \ |
| 631 | private: \ |
| 632 | static bool parse_ ## name(const char* str, int n, void* dest); \ |
| 633 | static bool parse_ ## name ## _radix( \ |
| 634 | const char* str, int n, void* dest, int radix); \ |
| 635 | public: \ |
| 636 | static bool parse_ ## name ## _hex(const char* str, int n, void* dest); \ |
| 637 | static bool parse_ ## name ## _octal(const char* str, int n, void* dest); \ |
| 638 | static bool parse_ ## name ## _cradix(const char* str, int n, void* dest) |
| 639 | |
| 640 | DECLARE_INTEGER_PARSER(short); |
| 641 | DECLARE_INTEGER_PARSER(ushort); |
| 642 | DECLARE_INTEGER_PARSER(int); |
| 643 | DECLARE_INTEGER_PARSER(uint); |
| 644 | DECLARE_INTEGER_PARSER(long); |
| 645 | DECLARE_INTEGER_PARSER(ulong); |
| 646 | DECLARE_INTEGER_PARSER(longlong); |
| 647 | DECLARE_INTEGER_PARSER(ulonglong); |
| 648 | |
| 649 | #undef DECLARE_INTEGER_PARSER |
| 650 | }; |
| 651 | |
| 652 | inline PCRE::Arg::Arg() : arg_(NULL), parser_(parse_null) { } |
| 653 | inline PCRE::Arg::Arg(void* p) : arg_(p), parser_(parse_null) { } |
| 654 | |
| 655 | inline bool PCRE::Arg::Parse(const char* str, int n) const { |
| 656 | return (*parser_)(str, n, arg_); |
| 657 | } |
| 658 | |
| 659 | // This part of the parser, appropriate only for ints, deals with bases |
| 660 | #define MAKE_INTEGER_PARSER(type, name) \ |
| 661 | inline PCRE::Arg Hex(type* ptr) { \ |
| 662 | return PCRE::Arg(ptr, PCRE::Arg::parse_ ## name ## _hex); } \ |
| 663 | inline PCRE::Arg Octal(type* ptr) { \ |
| 664 | return PCRE::Arg(ptr, PCRE::Arg::parse_ ## name ## _octal); } \ |
| 665 | inline PCRE::Arg CRadix(type* ptr) { \ |
| 666 | return PCRE::Arg(ptr, PCRE::Arg::parse_ ## name ## _cradix); } |
| 667 | |
| 668 | MAKE_INTEGER_PARSER(short, short); |
| 669 | MAKE_INTEGER_PARSER(unsigned short, ushort); |
| 670 | MAKE_INTEGER_PARSER(int, int); |
| 671 | MAKE_INTEGER_PARSER(unsigned int, uint); |
| 672 | MAKE_INTEGER_PARSER(long, long); |
| 673 | MAKE_INTEGER_PARSER(unsigned long, ulong); |
| 674 | MAKE_INTEGER_PARSER(long long, longlong); |
| 675 | MAKE_INTEGER_PARSER(unsigned long long, ulonglong); |
| 676 | |
| 677 | #undef MAKE_INTEGER_PARSER |
| 678 | |
| 679 | } // namespace re2 |