1018 lines
39 KiB
C++
1018 lines
39 KiB
C++
// 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 <stddef.h>
|
|
#include <stdint.h>
|
|
#include <algorithm>
|
|
#include <map>
|
|
#include <mutex>
|
|
#include <string>
|
|
#include <type_traits>
|
|
#include <vector>
|
|
|
|
#if defined(__APPLE__)
|
|
#include <TargetConditionals.h>
|
|
#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<int>* histogram) const;
|
|
int ReverseProgramFanout(std::vector<int>* 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 <typename F, typename SP>
|
|
static inline bool Apply(F f, SP sp, const RE2& re) {
|
|
return f(sp, re, NULL, 0);
|
|
}
|
|
|
|
template <typename F, typename SP, typename... A>
|
|
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 <typename... A>
|
|
static bool FullMatch(const StringPiece& text, const RE2& re, A&&... a) {
|
|
return Apply(FullMatchN, text, re, Arg(std::forward<A>(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 <typename... A>
|
|
static bool PartialMatch(const StringPiece& text, const RE2& re, A&&... a) {
|
|
return Apply(PartialMatchN, text, re, Arg(std::forward<A>(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 <typename... A>
|
|
static bool Consume(StringPiece* input, const RE2& re, A&&... a) {
|
|
return Apply(ConsumeN, input, re, Arg(std::forward<A>(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 <typename... A>
|
|
static bool FindAndConsume(StringPiece* input, const RE2& re, A&&... a) {
|
|
return Apply(FindAndConsumeN, input, re, Arg(std::forward<A>(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<std::string, int>& 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<int, std::string>& 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 <typename T>
|
|
static Arg CRadix(T* ptr);
|
|
template <typename T>
|
|
static Arg Hex(T* ptr);
|
|
template <typename T>
|
|
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<std::string, int>* named_groups_;
|
|
// Map from capture indices to names
|
|
mutable const std::map<int, std::string>* 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 <typename T> struct Parse3ary : public std::false_type {};
|
|
template <> struct Parse3ary<void> : public std::true_type {};
|
|
template <> struct Parse3ary<std::string> : public std::true_type {};
|
|
template <> struct Parse3ary<StringPiece> : public std::true_type {};
|
|
template <> struct Parse3ary<char> : public std::true_type {};
|
|
template <> struct Parse3ary<signed char> : public std::true_type {};
|
|
template <> struct Parse3ary<unsigned char> : public std::true_type {};
|
|
template <> struct Parse3ary<float> : public std::true_type {};
|
|
template <> struct Parse3ary<double> : public std::true_type {};
|
|
|
|
template <typename T>
|
|
bool Parse(const char* str, size_t n, T* dest);
|
|
|
|
// Types for which the 4-ary Parse() function template has specializations.
|
|
template <typename T> struct Parse4ary : public std::false_type {};
|
|
template <> struct Parse4ary<long> : public std::true_type {};
|
|
template <> struct Parse4ary<unsigned long> : public std::true_type {};
|
|
template <> struct Parse4ary<short> : public std::true_type {};
|
|
template <> struct Parse4ary<unsigned short> : public std::true_type {};
|
|
template <> struct Parse4ary<int> : public std::true_type {};
|
|
template <> struct Parse4ary<unsigned int> : public std::true_type {};
|
|
template <> struct Parse4ary<long long> : public std::true_type {};
|
|
template <> struct Parse4ary<unsigned long long> : public std::true_type {};
|
|
|
|
template <typename T>
|
|
bool Parse(const char* str, size_t n, T* dest, int radix);
|
|
|
|
} // namespace re2_internal
|
|
|
|
class RE2::Arg {
|
|
private:
|
|
template <typename T>
|
|
using CanParse3ary = typename std::enable_if<
|
|
re2_internal::Parse3ary<T>::value,
|
|
int>::type;
|
|
|
|
template <typename T>
|
|
using CanParse4ary = typename std::enable_if<
|
|
re2_internal::Parse4ary<T>::value,
|
|
int>::type;
|
|
|
|
#if !defined(_MSC_VER)
|
|
template <typename T>
|
|
using CanParseFrom = typename std::enable_if<
|
|
std::is_member_function_pointer<
|
|
decltype(static_cast<bool (T::*)(const char*, size_t)>(
|
|
&T::ParseFrom))>::value,
|
|
int>::type;
|
|
#endif
|
|
|
|
public:
|
|
Arg() : Arg(nullptr) {}
|
|
Arg(std::nullptr_t ptr) : arg_(ptr), parser_(DoNothing) {}
|
|
|
|
template <typename T, CanParse3ary<T> = 0>
|
|
Arg(T* ptr) : arg_(ptr), parser_(DoParse3ary<T>) {}
|
|
|
|
template <typename T, CanParse4ary<T> = 0>
|
|
Arg(T* ptr) : arg_(ptr), parser_(DoParse4ary<T>) {}
|
|
|
|
#if !defined(_MSC_VER)
|
|
template <typename T, CanParseFrom<T> = 0>
|
|
Arg(T* ptr) : arg_(ptr), parser_(DoParseFrom<T>) {}
|
|
#endif
|
|
|
|
typedef bool (*Parser)(const char* str, size_t n, void* dest);
|
|
|
|
template <typename T>
|
|
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 <typename T>
|
|
static bool DoParse3ary(const char* str, size_t n, void* dest) {
|
|
return re2_internal::Parse(str, n, reinterpret_cast<T*>(dest));
|
|
}
|
|
|
|
template <typename T>
|
|
static bool DoParse4ary(const char* str, size_t n, void* dest) {
|
|
return re2_internal::Parse(str, n, reinterpret_cast<T*>(dest), 10);
|
|
}
|
|
|
|
#if !defined(_MSC_VER)
|
|
template <typename T>
|
|
static bool DoParseFrom(const char* str, size_t n, void* dest) {
|
|
if (dest == NULL) return true;
|
|
return reinterpret_cast<T*>(dest)->ParseFrom(str, n);
|
|
}
|
|
#endif
|
|
|
|
void* arg_;
|
|
Parser parser_;
|
|
};
|
|
|
|
template <typename T>
|
|
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<T*>(dest), 0);
|
|
});
|
|
}
|
|
|
|
template <typename T>
|
|
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<T*>(dest), 16);
|
|
});
|
|
}
|
|
|
|
template <typename T>
|
|
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<T*>(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...
|
|
//
|
|
// As per https://github.com/google/re2/issues/325, thread_local support in
|
|
// MinGW seems to be buggy. (FWIW, Abseil folks also avoid it.)
|
|
#define RE2_HAVE_THREAD_LOCAL
|
|
#if (defined(__APPLE__) && !(defined(TARGET_OS_OSX) && TARGET_OS_OSX)) || defined(__MINGW32__)
|
|
#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_
|