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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+"
pattern()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.
error()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
PCRE_Options()531   PCRE_Options() : option_(PCRE::None), match_limit_(0), stack_limit_(0), report_errors_(true) {}
532   // accessors
option()533   PCRE::Option option() const { return option_; }
set_option(PCRE::Option option)534   void set_option(PCRE::Option option) {
535     option_ = option;
536   }
match_limit()537   int match_limit() const { return match_limit_; }
set_match_limit(int match_limit)538   void set_match_limit(int match_limit) {
539     match_limit_ = match_limit;
540   }
stack_limit()541   int stack_limit() const { return stack_limit_; }
set_stack_limit(int 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.
report_errors()548   bool report_errors() const { return report_errors_; }
set_report_errors(bool 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:
Parse(const char * str,int n,void * dest)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
Arg(T * p)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 
Arg()652 inline PCRE::Arg::Arg() : arg_(NULL), parser_(parse_null) { }
Arg(void * p)653 inline PCRE::Arg::Arg(void* p) : arg_(p), parser_(parse_null) { }
654 
Parse(const char * str,int n)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
680