// Copyright 2003-2009 The RE2 Authors. All Rights Reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. #ifndef RE2_RE2_H_ #define RE2_RE2_H_ // C++ interface to the re2 regular-expression library. // RE2 supports Perl-style regular expressions (with extensions like // \d, \w, \s, ...). // // ----------------------------------------------------------------------- // REGEXP SYNTAX: // // This module uses the re2 library and hence supports // its syntax for regular expressions, which is similar to Perl's with // some of the more complicated things thrown away. In particular, // backreferences and generalized assertions are not available, nor is \Z. // // See https://github.com/google/re2/wiki/Syntax for the syntax // supported by RE2, and a comparison with PCRE and PERL regexps. // // For those not familiar with Perl's regular expressions, // here are some examples of the most commonly used extensions: // // "hello (\\w+) world" -- \w matches a "word" character // "version (\\d+)" -- \d matches a digit // "hello\\s+world" -- \s matches any whitespace character // "\\b(\\w+)\\b" -- \b matches non-empty string at word boundary // "(?i)hello" -- (?i) turns on case-insensitive matching // "/\\*(.*?)\\*/" -- .*? matches . minimum no. of times possible // // The double backslashes are needed when writing C++ string literals. // However, they should NOT be used when writing C++11 raw string literals: // // R"(hello (\w+) world)" -- \w matches a "word" character // R"(version (\d+))" -- \d matches a digit // R"(hello\s+world)" -- \s matches any whitespace character // R"(\b(\w+)\b)" -- \b matches non-empty string at word boundary // R"((?i)hello)" -- (?i) turns on case-insensitive matching // R"(/\*(.*?)\*/)" -- .*? matches . minimum no. of times possible // // When using UTF-8 encoding, case-insensitive matching will perform // simple case folding, not full case folding. // // ----------------------------------------------------------------------- // MATCHING INTERFACE: // // The "FullMatch" operation checks that supplied text matches a // supplied pattern exactly. // // Example: successful match // CHECK(RE2::FullMatch("hello", "h.*o")); // // Example: unsuccessful match (requires full match): // CHECK(!RE2::FullMatch("hello", "e")); // // ----------------------------------------------------------------------- // UTF-8 AND THE MATCHING INTERFACE: // // By default, the pattern and input text are interpreted as UTF-8. // The RE2::Latin1 option causes them to be interpreted as Latin-1. // // Example: // CHECK(RE2::FullMatch(utf8_string, RE2(utf8_pattern))); // CHECK(RE2::FullMatch(latin1_string, RE2(latin1_pattern, RE2::Latin1))); // // ----------------------------------------------------------------------- // MATCHING WITH SUBSTRING EXTRACTION: // // You can supply extra pointer arguments to extract matched substrings. // On match failure, none of the pointees will have been modified. // On match success, the substrings will be converted (as necessary) and // their values will be assigned to their pointees until all conversions // have succeeded or one conversion has failed. // On conversion failure, the pointees will be in an indeterminate state // because the caller has no way of knowing which conversion failed. // However, conversion cannot fail for types like string and StringPiece // that do not inspect the substring contents. Hence, in the common case // where all of the pointees are of such types, failure is always due to // match failure and thus none of the pointees will have been modified. // // Example: extracts "ruby" into "s" and 1234 into "i" // int i; // std::string s; // CHECK(RE2::FullMatch("ruby:1234", "(\\w+):(\\d+)", &s, &i)); // // Example: fails because string cannot be stored in integer // CHECK(!RE2::FullMatch("ruby", "(.*)", &i)); // // Example: fails because there aren't enough sub-patterns // CHECK(!RE2::FullMatch("ruby:1234", "\\w+:\\d+", &s)); // // Example: does not try to extract any extra sub-patterns // CHECK(RE2::FullMatch("ruby:1234", "(\\w+):(\\d+)", &s)); // // Example: does not try to extract into NULL // CHECK(RE2::FullMatch("ruby:1234", "(\\w+):(\\d+)", NULL, &i)); // // Example: integer overflow causes failure // CHECK(!RE2::FullMatch("ruby:1234567891234", "\\w+:(\\d+)", &i)); // // NOTE(rsc): Asking for substrings slows successful matches quite a bit. // This may get a little faster in the future, but right now is slower // than PCRE. On the other hand, failed matches run *very* fast (faster // than PCRE), as do matches without substring extraction. // // ----------------------------------------------------------------------- // PARTIAL MATCHES // // You can use the "PartialMatch" operation when you want the pattern // to match any substring of the text. // // Example: simple search for a string: // CHECK(RE2::PartialMatch("hello", "ell")); // // Example: find first number in a string // int number; // CHECK(RE2::PartialMatch("x*100 + 20", "(\\d+)", &number)); // CHECK_EQ(number, 100); // // ----------------------------------------------------------------------- // PRE-COMPILED REGULAR EXPRESSIONS // // RE2 makes it easy to use any string as a regular expression, without // requiring a separate compilation step. // // If speed is of the essence, you can create a pre-compiled "RE2" // object from the pattern and use it multiple times. If you do so, // you can typically parse text faster than with sscanf. // // Example: precompile pattern for faster matching: // RE2 pattern("h.*o"); // while (ReadLine(&str)) { // if (RE2::FullMatch(str, pattern)) ...; // } // // ----------------------------------------------------------------------- // SCANNING TEXT INCREMENTALLY // // The "Consume" operation may be useful if you want to repeatedly // match regular expressions at the front of a string and skip over // them as they match. This requires use of the "StringPiece" type, // which represents a sub-range of a real string. // // Example: read lines of the form "var = value" from a string. // std::string contents = ...; // Fill string somehow // StringPiece input(contents); // Wrap a StringPiece around it // // std::string var; // int value; // while (RE2::Consume(&input, "(\\w+) = (\\d+)\n", &var, &value)) { // ...; // } // // Each successful call to "Consume" will set "var/value", and also // advance "input" so it points past the matched text. Note that if the // regular expression matches an empty string, input will advance // by 0 bytes. If the regular expression being used might match // an empty string, the loop body must check for this case and either // advance the string or break out of the loop. // // The "FindAndConsume" operation is similar to "Consume" but does not // anchor your match at the beginning of the string. For example, you // could extract all words from a string by repeatedly calling // RE2::FindAndConsume(&input, "(\\w+)", &word) // // ----------------------------------------------------------------------- // USING VARIABLE NUMBER OF ARGUMENTS // // The above operations require you to know the number of arguments // when you write the code. This is not always possible or easy (for // example, the regular expression may be calculated at run time). // You can use the "N" version of the operations when the number of // match arguments are determined at run time. // // Example: // const RE2::Arg* args[10]; // int n; // // ... populate args with pointers to RE2::Arg values ... // // ... set n to the number of RE2::Arg objects ... // bool match = RE2::FullMatchN(input, pattern, args, n); // // The last statement is equivalent to // // bool match = RE2::FullMatch(input, pattern, // *args[0], *args[1], ..., *args[n - 1]); // // ----------------------------------------------------------------------- // PARSING HEX/OCTAL/C-RADIX NUMBERS // // By default, if you pass a pointer to a numeric value, the // corresponding text is interpreted as a base-10 number. You can // instead wrap the pointer with a call to one of the operators Hex(), // Octal(), or CRadix() to interpret the text in another base. The // CRadix operator interprets C-style "0" (base-8) and "0x" (base-16) // prefixes, but defaults to base-10. // // Example: // int a, b, c, d; // CHECK(RE2::FullMatch("100 40 0100 0x40", "(.*) (.*) (.*) (.*)", // RE2::Octal(&a), RE2::Hex(&b), RE2::CRadix(&c), RE2::CRadix(&d)); // will leave 64 in a, b, c, and d. #include #include #include #include #include #include #include #include #if defined(__APPLE__) #include #endif #include "re2/stringpiece.h" namespace re2 { class Prog; class Regexp; } // namespace re2 namespace re2 { // Interface for regular expression matching. Also corresponds to a // pre-compiled regular expression. An "RE2" object is safe for // concurrent use by multiple threads. class RE2 { public: // We convert user-passed pointers into special Arg objects class Arg; class Options; // Defined in set.h. class Set; enum ErrorCode { NoError = 0, // Unexpected error ErrorInternal, // Parse errors ErrorBadEscape, // bad escape sequence ErrorBadCharClass, // bad character class ErrorBadCharRange, // bad character class range ErrorMissingBracket, // missing closing ] ErrorMissingParen, // missing closing ) ErrorUnexpectedParen, // unexpected closing ) ErrorTrailingBackslash, // trailing \ at end of regexp ErrorRepeatArgument, // repeat argument missing, e.g. "*" ErrorRepeatSize, // bad repetition argument ErrorRepeatOp, // bad repetition operator ErrorBadPerlOp, // bad perl operator ErrorBadUTF8, // invalid UTF-8 in regexp ErrorBadNamedCapture, // bad named capture group ErrorPatternTooLarge // pattern too large (compile failed) }; // Predefined common options. // If you need more complicated things, instantiate // an Option class, possibly passing one of these to // the Option constructor, change the settings, and pass that // Option class to the RE2 constructor. enum CannedOptions { DefaultOptions = 0, Latin1, // treat input as Latin-1 (default UTF-8) POSIX, // POSIX syntax, leftmost-longest match Quiet // do not log about regexp parse errors }; // Need to have the const char* and const std::string& forms for implicit // conversions when passing string literals to FullMatch and PartialMatch. // Otherwise the StringPiece form would be sufficient. #ifndef SWIG RE2(const char* pattern); RE2(const std::string& pattern); #endif RE2(const StringPiece& pattern); RE2(const StringPiece& pattern, const Options& options); ~RE2(); // Returns whether RE2 was created properly. bool ok() const { return error_code() == NoError; } // The string specification for this RE2. E.g. // RE2 re("ab*c?d+"); // re.pattern(); // "ab*c?d+" const std::string& pattern() const { return pattern_; } // If RE2 could not be created properly, returns an error string. // Else returns the empty string. const std::string& error() const { return *error_; } // If RE2 could not be created properly, returns an error code. // Else returns RE2::NoError (== 0). ErrorCode error_code() const { return error_code_; } // If RE2 could not be created properly, returns the offending // portion of the regexp. const std::string& error_arg() const { return error_arg_; } // Returns the program size, a very approximate measure of a regexp's "cost". // Larger numbers are more expensive than smaller numbers. int ProgramSize() const; int ReverseProgramSize() const; // If histogram is not null, outputs the program fanout // as a histogram bucketed by powers of 2. // Returns the number of the largest non-empty bucket. int ProgramFanout(std::vector* histogram) const; int ReverseProgramFanout(std::vector* histogram) const; // Returns the underlying Regexp; not for general use. // Returns entire_regexp_ so that callers don't need // to know about prefix_ and prefix_foldcase_. re2::Regexp* Regexp() const { return entire_regexp_; } /***** The array-based matching interface ******/ // The functions here have names ending in 'N' and are used to implement // the functions whose names are the prefix before the 'N'. It is sometimes // useful to invoke them directly, but the syntax is awkward, so the 'N'-less // versions should be preferred. static bool FullMatchN(const StringPiece& text, const RE2& re, const Arg* const args[], int n); static bool PartialMatchN(const StringPiece& text, const RE2& re, const Arg* const args[], int n); static bool ConsumeN(StringPiece* input, const RE2& re, const Arg* const args[], int n); static bool FindAndConsumeN(StringPiece* input, const RE2& re, const Arg* const args[], int n); #ifndef SWIG private: template static inline bool Apply(F f, SP sp, const RE2& re) { return f(sp, re, NULL, 0); } template static inline bool Apply(F f, SP sp, const RE2& re, const A&... a) { const Arg* const args[] = {&a...}; const int n = sizeof...(a); return f(sp, re, args, n); } public: // In order to allow FullMatch() et al. to be called with a varying number // of arguments of varying types, we use two layers of variadic templates. // The first layer constructs the temporary Arg objects. The second layer // (above) constructs the array of pointers to the temporary Arg objects. /***** The useful part: the matching interface *****/ // Matches "text" against "re". If pointer arguments are // supplied, copies matched sub-patterns into them. // // You can pass in a "const char*" or a "std::string" for "text". // You can pass in a "const char*" or a "std::string" or a "RE2" for "re". // // The provided pointer arguments can be pointers to any scalar numeric // type, or one of: // std::string (matched piece is copied to string) // StringPiece (StringPiece is mutated to point to matched piece) // T (where "bool T::ParseFrom(const char*, size_t)" exists) // (void*)NULL (the corresponding matched sub-pattern is not copied) // // Returns true iff all of the following conditions are satisfied: // a. "text" matches "re" fully - from the beginning to the end of "text". // b. The number of matched sub-patterns is >= number of supplied pointers. // c. The "i"th argument has a suitable type for holding the // string captured as the "i"th sub-pattern. If you pass in // NULL for the "i"th argument, or pass fewer arguments than // number of sub-patterns, the "i"th captured sub-pattern is // ignored. // // CAVEAT: An optional sub-pattern that does not exist in the // matched string is assigned the empty string. Therefore, the // following will return false (because the empty string is not a // valid number): // int number; // RE2::FullMatch("abc", "[a-z]+(\\d+)?", &number); template static bool FullMatch(const StringPiece& text, const RE2& re, A&&... a) { return Apply(FullMatchN, text, re, Arg(std::forward(a))...); } // Like FullMatch(), except that "re" is allowed to match a substring // of "text". // // Returns true iff all of the following conditions are satisfied: // a. "text" matches "re" partially - for some substring of "text". // b. The number of matched sub-patterns is >= number of supplied pointers. // c. The "i"th argument has a suitable type for holding the // string captured as the "i"th sub-pattern. If you pass in // NULL for the "i"th argument, or pass fewer arguments than // number of sub-patterns, the "i"th captured sub-pattern is // ignored. template static bool PartialMatch(const StringPiece& text, const RE2& re, A&&... a) { return Apply(PartialMatchN, text, re, Arg(std::forward(a))...); } // Like FullMatch() and PartialMatch(), except that "re" has to match // a prefix of the text, and "input" is advanced past the matched // text. Note: "input" is modified iff this routine returns true // and "re" matched a non-empty substring of "input". // // Returns true iff all of the following conditions are satisfied: // a. "input" matches "re" partially - for some prefix of "input". // b. The number of matched sub-patterns is >= number of supplied pointers. // c. The "i"th argument has a suitable type for holding the // string captured as the "i"th sub-pattern. If you pass in // NULL for the "i"th argument, or pass fewer arguments than // number of sub-patterns, the "i"th captured sub-pattern is // ignored. template static bool Consume(StringPiece* input, const RE2& re, A&&... a) { return Apply(ConsumeN, input, re, Arg(std::forward(a))...); } // Like Consume(), but does not anchor the match at the beginning of // the text. That is, "re" need not start its match at the beginning // of "input". For example, "FindAndConsume(s, "(\\w+)", &word)" finds // the next word in "s" and stores it in "word". // // Returns true iff all of the following conditions are satisfied: // a. "input" matches "re" partially - for some substring of "input". // b. The number of matched sub-patterns is >= number of supplied pointers. // c. The "i"th argument has a suitable type for holding the // string captured as the "i"th sub-pattern. If you pass in // NULL for the "i"th argument, or pass fewer arguments than // number of sub-patterns, the "i"th captured sub-pattern is // ignored. template static bool FindAndConsume(StringPiece* input, const RE2& re, A&&... a) { return Apply(FindAndConsumeN, input, re, Arg(std::forward(a))...); } #endif // Replace the first match of "re" in "str" with "rewrite". // Within "rewrite", backslash-escaped digits (\1 to \9) can be // used to insert text matching corresponding parenthesized group // from the pattern. \0 in "rewrite" refers to the entire matching // text. E.g., // // std::string s = "yabba dabba doo"; // CHECK(RE2::Replace(&s, "b+", "d")); // // will leave "s" containing "yada dabba doo" // // Returns true if the pattern matches and a replacement occurs, // false otherwise. static bool Replace(std::string* str, const RE2& re, const StringPiece& rewrite); // Like Replace(), except replaces successive non-overlapping occurrences // of the pattern in the string with the rewrite. E.g. // // std::string s = "yabba dabba doo"; // CHECK(RE2::GlobalReplace(&s, "b+", "d")); // // will leave "s" containing "yada dada doo" // Replacements are not subject to re-matching. // // Because GlobalReplace only replaces non-overlapping matches, // replacing "ana" within "banana" makes only one replacement, not two. // // Returns the number of replacements made. static int GlobalReplace(std::string* str, const RE2& re, const StringPiece& rewrite); // Like Replace, except that if the pattern matches, "rewrite" // is copied into "out" with substitutions. The non-matching // portions of "text" are ignored. // // Returns true iff a match occurred and the extraction happened // successfully; if no match occurs, the string is left unaffected. // // REQUIRES: "text" must not alias any part of "*out". static bool Extract(const StringPiece& text, const RE2& re, const StringPiece& rewrite, std::string* out); // Escapes all potentially meaningful regexp characters in // 'unquoted'. The returned string, used as a regular expression, // will match exactly the original string. For example, // 1.5-2.0? // may become: // 1\.5\-2\.0\? static std::string QuoteMeta(const StringPiece& unquoted); // Computes range for any strings matching regexp. The min and max can in // some cases be arbitrarily precise, so the caller gets to specify the // maximum desired length of string returned. // // Assuming PossibleMatchRange(&min, &max, N) returns successfully, any // string s that is an anchored match for this regexp satisfies // min <= s && s <= max. // // Note that PossibleMatchRange() will only consider the first copy of an // infinitely repeated element (i.e., any regexp element followed by a '*' or // '+' operator). Regexps with "{N}" constructions are not affected, as those // do not compile down to infinite repetitions. // // Returns true on success, false on error. bool PossibleMatchRange(std::string* min, std::string* max, int maxlen) const; // Generic matching interface // Type of match. enum Anchor { UNANCHORED, // No anchoring ANCHOR_START, // Anchor at start only ANCHOR_BOTH // Anchor at start and end }; // Return the number of capturing subpatterns, or -1 if the // regexp wasn't valid on construction. The overall match ($0) // does not count: if the regexp is "(a)(b)", returns 2. int NumberOfCapturingGroups() const { return num_captures_; } // Return a map from names to capturing indices. // The map records the index of the leftmost group // with the given name. // Only valid until the re is deleted. const std::map& NamedCapturingGroups() const; // Return a map from capturing indices to names. // The map has no entries for unnamed groups. // Only valid until the re is deleted. const std::map& CapturingGroupNames() const; // General matching routine. // Match against text starting at offset startpos // and stopping the search at offset endpos. // Returns true if match found, false if not. // On a successful match, fills in submatch[] (up to nsubmatch entries) // with information about submatches. // I.e. matching RE2("(foo)|(bar)baz") on "barbazbla" will return true, with // submatch[0] = "barbaz", submatch[1].data() = NULL, submatch[2] = "bar", // submatch[3].data() = NULL, ..., up to submatch[nsubmatch-1].data() = NULL. // Caveat: submatch[] may be clobbered even on match failure. // // Don't ask for more match information than you will use: // runs much faster with nsubmatch == 1 than nsubmatch > 1, and // runs even faster if nsubmatch == 0. // Doesn't make sense to use nsubmatch > 1 + NumberOfCapturingGroups(), // but will be handled correctly. // // Passing text == StringPiece(NULL, 0) will be handled like any other // empty string, but note that on return, it will not be possible to tell // whether submatch i matched the empty string or did not match: // either way, submatch[i].data() == NULL. bool Match(const StringPiece& text, size_t startpos, size_t endpos, Anchor re_anchor, StringPiece* submatch, int nsubmatch) const; // Check that the given rewrite string is suitable for use with this // regular expression. It checks that: // * The regular expression has enough parenthesized subexpressions // to satisfy all of the \N tokens in rewrite // * The rewrite string doesn't have any syntax errors. E.g., // '\' followed by anything other than a digit or '\'. // A true return value guarantees that Replace() and Extract() won't // fail because of a bad rewrite string. bool CheckRewriteString(const StringPiece& rewrite, std::string* error) const; // Returns the maximum submatch needed for the rewrite to be done by // Replace(). E.g. if rewrite == "foo \\2,\\1", returns 2. static int MaxSubmatch(const StringPiece& rewrite); // Append the "rewrite" string, with backslash subsitutions from "vec", // to string "out". // Returns true on success. This method can fail because of a malformed // rewrite string. CheckRewriteString guarantees that the rewrite will // be sucessful. bool Rewrite(std::string* out, const StringPiece& rewrite, const StringPiece* vec, int veclen) const; // Constructor options class Options { public: // The options are (defaults in parentheses): // // utf8 (true) text and pattern are UTF-8; otherwise Latin-1 // posix_syntax (false) restrict regexps to POSIX egrep syntax // longest_match (false) search for longest match, not first match // log_errors (true) log syntax and execution errors to ERROR // max_mem (see below) approx. max memory footprint of RE2 // literal (false) interpret string as literal, not regexp // never_nl (false) never match \n, even if it is in regexp // dot_nl (false) dot matches everything including new line // never_capture (false) parse all parens as non-capturing // case_sensitive (true) match is case-sensitive (regexp can override // with (?i) unless in posix_syntax mode) // // The following options are only consulted when posix_syntax == true. // When posix_syntax == false, these features are always enabled and // cannot be turned off; to perform multi-line matching in that case, // begin the regexp with (?m). // perl_classes (false) allow Perl's \d \s \w \D \S \W // word_boundary (false) allow Perl's \b \B (word boundary and not) // one_line (false) ^ and $ only match beginning and end of text // // The max_mem option controls how much memory can be used // to hold the compiled form of the regexp (the Prog) and // its cached DFA graphs. Code Search placed limits on the number // of Prog instructions and DFA states: 10,000 for both. // In RE2, those limits would translate to about 240 KB per Prog // and perhaps 2.5 MB per DFA (DFA state sizes vary by regexp; RE2 does a // better job of keeping them small than Code Search did). // Each RE2 has two Progs (one forward, one reverse), and each Prog // can have two DFAs (one first match, one longest match). // That makes 4 DFAs: // // forward, first-match - used for UNANCHORED or ANCHOR_START searches // if opt.longest_match() == false // forward, longest-match - used for all ANCHOR_BOTH searches, // and the other two kinds if // opt.longest_match() == true // reverse, first-match - never used // reverse, longest-match - used as second phase for unanchored searches // // The RE2 memory budget is statically divided between the two // Progs and then the DFAs: two thirds to the forward Prog // and one third to the reverse Prog. The forward Prog gives half // of what it has left over to each of its DFAs. The reverse Prog // gives it all to its longest-match DFA. // // Once a DFA fills its budget, it flushes its cache and starts over. // If this happens too often, RE2 falls back on the NFA implementation. // For now, make the default budget something close to Code Search. static const int kDefaultMaxMem = 8<<20; enum Encoding { EncodingUTF8 = 1, EncodingLatin1 }; Options() : encoding_(EncodingUTF8), posix_syntax_(false), longest_match_(false), log_errors_(true), max_mem_(kDefaultMaxMem), literal_(false), never_nl_(false), dot_nl_(false), never_capture_(false), case_sensitive_(true), perl_classes_(false), word_boundary_(false), one_line_(false) { } /*implicit*/ Options(CannedOptions); Encoding encoding() const { return encoding_; } void set_encoding(Encoding encoding) { encoding_ = encoding; } bool posix_syntax() const { return posix_syntax_; } void set_posix_syntax(bool b) { posix_syntax_ = b; } bool longest_match() const { return longest_match_; } void set_longest_match(bool b) { longest_match_ = b; } bool log_errors() const { return log_errors_; } void set_log_errors(bool b) { log_errors_ = b; } int64_t max_mem() const { return max_mem_; } void set_max_mem(int64_t m) { max_mem_ = m; } bool literal() const { return literal_; } void set_literal(bool b) { literal_ = b; } bool never_nl() const { return never_nl_; } void set_never_nl(bool b) { never_nl_ = b; } bool dot_nl() const { return dot_nl_; } void set_dot_nl(bool b) { dot_nl_ = b; } bool never_capture() const { return never_capture_; } void set_never_capture(bool b) { never_capture_ = b; } bool case_sensitive() const { return case_sensitive_; } void set_case_sensitive(bool b) { case_sensitive_ = b; } bool perl_classes() const { return perl_classes_; } void set_perl_classes(bool b) { perl_classes_ = b; } bool word_boundary() const { return word_boundary_; } void set_word_boundary(bool b) { word_boundary_ = b; } bool one_line() const { return one_line_; } void set_one_line(bool b) { one_line_ = b; } void Copy(const Options& src) { *this = src; } int ParseFlags() const; private: Encoding encoding_; bool posix_syntax_; bool longest_match_; bool log_errors_; int64_t max_mem_; bool literal_; bool never_nl_; bool dot_nl_; bool never_capture_; bool case_sensitive_; bool perl_classes_; bool word_boundary_; bool one_line_; }; // Returns the options set in the constructor. const Options& options() const { return options_; } // Argument converters; see below. template static Arg CRadix(T* ptr); template static Arg Hex(T* ptr); template static Arg Octal(T* ptr); private: void Init(const StringPiece& pattern, const Options& options); bool DoMatch(const StringPiece& text, Anchor re_anchor, size_t* consumed, const Arg* const args[], int n) const; re2::Prog* ReverseProg() const; std::string pattern_; // string regular expression Options options_; // option flags re2::Regexp* entire_regexp_; // parsed regular expression const std::string* error_; // error indicator (or points to empty string) ErrorCode error_code_; // error code std::string error_arg_; // fragment of regexp showing error std::string prefix_; // required prefix (before suffix_regexp_) bool prefix_foldcase_; // prefix_ is ASCII case-insensitive re2::Regexp* suffix_regexp_; // parsed regular expression, prefix_ removed re2::Prog* prog_; // compiled program for regexp int num_captures_; // number of capturing groups bool is_one_pass_; // can use prog_->SearchOnePass? // Reverse Prog for DFA execution only mutable re2::Prog* rprog_; // Map from capture names to indices mutable const std::map* named_groups_; // Map from capture indices to names mutable const std::map* group_names_; mutable std::once_flag rprog_once_; mutable std::once_flag named_groups_once_; mutable std::once_flag group_names_once_; RE2(const RE2&) = delete; RE2& operator=(const RE2&) = delete; }; /***** Implementation details *****/ namespace re2_internal { // Types for which the 3-ary Parse() function template has specializations. template struct Parse3ary : public std::false_type {}; template <> struct Parse3ary : public std::true_type {}; template <> struct Parse3ary : public std::true_type {}; template <> struct Parse3ary : public std::true_type {}; template <> struct Parse3ary : public std::true_type {}; template <> struct Parse3ary : public std::true_type {}; template <> struct Parse3ary : public std::true_type {}; template <> struct Parse3ary : public std::true_type {}; template <> struct Parse3ary : public std::true_type {}; template bool Parse(const char* str, size_t n, T* dest); // Types for which the 4-ary Parse() function template has specializations. template struct Parse4ary : public std::false_type {}; template <> struct Parse4ary : public std::true_type {}; template <> struct Parse4ary : public std::true_type {}; template <> struct Parse4ary : public std::true_type {}; template <> struct Parse4ary : public std::true_type {}; template <> struct Parse4ary : public std::true_type {}; template <> struct Parse4ary : public std::true_type {}; template <> struct Parse4ary : public std::true_type {}; template <> struct Parse4ary : public std::true_type {}; template bool Parse(const char* str, size_t n, T* dest, int radix); } // namespace re2_internal class RE2::Arg { private: template using CanParse3ary = typename std::enable_if< re2_internal::Parse3ary::value, int>::type; template using CanParse4ary = typename std::enable_if< re2_internal::Parse4ary::value, int>::type; #if !defined(_MSC_VER) template using CanParseFrom = typename std::enable_if< std::is_member_function_pointer::value, int>::type; #endif public: Arg() : Arg(nullptr) {} Arg(std::nullptr_t ptr) : arg_(ptr), parser_(DoNothing) {} template = 0> Arg(T* ptr) : arg_(ptr), parser_(DoParse3ary) {} template = 0> Arg(T* ptr) : arg_(ptr), parser_(DoParse4ary) {} #if !defined(_MSC_VER) template = 0> Arg(T* ptr) : arg_(ptr), parser_(DoParseFrom) {} #endif typedef bool (*Parser)(const char* str, size_t n, void* dest); template Arg(T* ptr, Parser parser) : arg_(ptr), parser_(parser) {} bool Parse(const char* str, size_t n) const { return (*parser_)(str, n, arg_); } private: static bool DoNothing(const char* /*str*/, size_t /*n*/, void* /*dest*/) { return true; } template static bool DoParse3ary(const char* str, size_t n, void* dest) { return re2_internal::Parse(str, n, reinterpret_cast(dest)); } template static bool DoParse4ary(const char* str, size_t n, void* dest) { return re2_internal::Parse(str, n, reinterpret_cast(dest), 10); } #if !defined(_MSC_VER) template static bool DoParseFrom(const char* str, size_t n, void* dest) { if (dest == NULL) return true; return reinterpret_cast(dest)->ParseFrom(str, n); } #endif void* arg_; Parser parser_; }; template inline RE2::Arg RE2::CRadix(T* ptr) { return RE2::Arg(ptr, [](const char* str, size_t n, void* dest) -> bool { return re2_internal::Parse(str, n, reinterpret_cast(dest), 0); }); } template inline RE2::Arg RE2::Hex(T* ptr) { return RE2::Arg(ptr, [](const char* str, size_t n, void* dest) -> bool { return re2_internal::Parse(str, n, reinterpret_cast(dest), 16); }); } template inline RE2::Arg RE2::Octal(T* ptr) { return RE2::Arg(ptr, [](const char* str, size_t n, void* dest) -> bool { return re2_internal::Parse(str, n, reinterpret_cast(dest), 8); }); } #ifndef SWIG // Silence warnings about missing initializers for members of LazyRE2. #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 6 #pragma GCC diagnostic ignored "-Wmissing-field-initializers" #endif // Helper for writing global or static RE2s safely. // Write // static LazyRE2 re = {".*"}; // and then use *re instead of writing // static RE2 re(".*"); // The former is more careful about multithreaded // situations than the latter. // // N.B. This class never deletes the RE2 object that // it constructs: that's a feature, so that it can be used // for global and function static variables. class LazyRE2 { private: struct NoArg {}; public: typedef RE2 element_type; // support std::pointer_traits // Constructor omitted to preserve braced initialization in C++98. // Pretend to be a pointer to Type (never NULL due to on-demand creation): RE2& operator*() const { return *get(); } RE2* operator->() const { return get(); } // Named accessor/initializer: RE2* get() const { std::call_once(once_, &LazyRE2::Init, this); return ptr_; } // All data fields must be public to support {"foo"} initialization. const char* pattern_; RE2::CannedOptions options_; NoArg barrier_against_excess_initializers_; mutable RE2* ptr_; mutable std::once_flag once_; private: static void Init(const LazyRE2* lazy_re2) { lazy_re2->ptr_ = new RE2(lazy_re2->pattern_, lazy_re2->options_); } void operator=(const LazyRE2&); // disallowed }; #endif namespace hooks { // Most platforms support thread_local. Older versions of iOS don't support // thread_local, but for the sake of brevity, we lump together all versions // of Apple platforms that aren't macOS. If an iOS application really needs // the context pointee someday, we can get more specific then... #define RE2_HAVE_THREAD_LOCAL #if defined(__APPLE__) && !TARGET_OS_OSX #undef RE2_HAVE_THREAD_LOCAL #endif // A hook must not make any assumptions regarding the lifetime of the context // pointee beyond the current invocation of the hook. Pointers and references // obtained via the context pointee should be considered invalidated when the // hook returns. Hence, any data about the context pointee (e.g. its pattern) // would have to be copied in order for it to be kept for an indefinite time. // // A hook must not use RE2 for matching. Control flow reentering RE2::Match() // could result in infinite mutual recursion. To discourage that possibility, // RE2 will not maintain the context pointer correctly when used in that way. #ifdef RE2_HAVE_THREAD_LOCAL extern thread_local const RE2* context; #endif struct DFAStateCacheReset { int64_t state_budget; size_t state_cache_size; }; struct DFASearchFailure { // Nothing yet... }; #define DECLARE_HOOK(type) \ using type##Callback = void(const type&); \ void Set##type##Hook(type##Callback* cb); \ type##Callback* Get##type##Hook(); DECLARE_HOOK(DFAStateCacheReset) DECLARE_HOOK(DFASearchFailure) #undef DECLARE_HOOK } // namespace hooks } // namespace re2 using re2::RE2; using re2::LazyRE2; #endif // RE2_RE2_H_