LLVM  14.0.0git
Regex.h
Go to the documentation of this file.
1 //===-- Regex.h - Regular Expression matcher implementation -*- C++ -*-----===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements a POSIX regular expression matcher. Both Basic and
10 // Extended POSIX regular expressions (ERE) are supported. EREs were extended
11 // to support backreferences in matches.
12 // This implementation also supports matching strings with embedded NUL chars.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_SUPPORT_REGEX_H
17 #define LLVM_SUPPORT_REGEX_H
18 
19 #include "llvm/ADT/BitmaskEnum.h"
20 #include <string>
21 
22 struct llvm_regex;
23 
24 namespace llvm {
25  class StringRef;
26  template<typename T> class SmallVectorImpl;
27 
28  class Regex {
29  public:
30  enum RegexFlags : unsigned {
31  NoFlags = 0,
32  /// Compile for matching that ignores upper/lower case distinctions.
34  /// Compile for newline-sensitive matching. With this flag '[^' bracket
35  /// expressions and '.' never match newline. A ^ anchor matches the
36  /// null string after any newline in the string in addition to its normal
37  /// function, and the $ anchor matches the null string before any
38  /// newline in the string in addition to its normal function.
39  Newline = 2,
40  /// By default, the POSIX extended regular expression (ERE) syntax is
41  /// assumed. Pass this flag to turn on basic regular expressions (BRE)
42  /// instead.
44 
46  };
47 
48  Regex();
49  /// Compiles the given regular expression \p Regex.
50  ///
51  /// \param Regex - referenced string is no longer needed after this
52  /// constructor does finish. Only its compiled form is kept stored.
54  Regex(StringRef Regex, unsigned Flags);
55  Regex(const Regex &) = delete;
56  Regex &operator=(Regex regex) {
57  std::swap(preg, regex.preg);
58  std::swap(error, regex.error);
59  return *this;
60  }
61  Regex(Regex &&regex);
62  ~Regex();
63 
64  /// isValid - returns the error encountered during regex compilation, if
65  /// any.
66  bool isValid(std::string &Error) const;
67  bool isValid() const { return !error; }
68 
69  /// getNumMatches - In a valid regex, return the number of parenthesized
70  /// matches it contains. The number filled in by match will include this
71  /// many entries plus one for the whole regex (as element 0).
72  unsigned getNumMatches() const;
73 
74  /// matches - Match the regex against a given \p String.
75  ///
76  /// \param Matches - If given, on a successful match this will be filled in
77  /// with references to the matched group expressions (inside \p String),
78  /// the first group is always the entire pattern.
79  ///
80  /// \param Error - If non-null, any errors in the matching will be recorded
81  /// as a non-empty string. If there is no error, it will be an empty string.
82  ///
83  /// This returns true on a successful match.
84  bool match(StringRef String, SmallVectorImpl<StringRef> *Matches = nullptr,
85  std::string *Error = nullptr) const;
86 
87  /// sub - Return the result of replacing the first match of the regex in
88  /// \p String with the \p Repl string. Backreferences like "\0" in the
89  /// replacement string are replaced with the appropriate match substring.
90  ///
91  /// Note that the replacement string has backslash escaping performed on
92  /// it. Invalid backreferences are ignored (replaced by empty strings).
93  ///
94  /// \param Error If non-null, any errors in the substitution (invalid
95  /// backreferences, trailing backslashes) will be recorded as a non-empty
96  /// string. If there is no error, it will be an empty string.
97  std::string sub(StringRef Repl, StringRef String,
98  std::string *Error = nullptr) const;
99 
100  /// If this function returns true, ^Str$ is an extended regular
101  /// expression that matches Str and only Str.
102  static bool isLiteralERE(StringRef Str);
103 
104  /// Turn String into a regex by escaping its special characters.
105  static std::string escape(StringRef String);
106 
107  private:
108  struct llvm_regex *preg;
109  int error;
110  };
111 }
112 
113 #endif // LLVM_SUPPORT_REGEX_H
llvm
This file implements support for optimizing divisions by a constant.
Definition: AllocatorList.h:23
LLVM_MARK_AS_BITMASK_ENUM
#define LLVM_MARK_AS_BITMASK_ENUM(LargestValue)
LLVM_MARK_AS_BITMASK_ENUM lets you opt in an individual enum type so you can perform bitwise operatio...
Definition: BitmaskEnum.h:41
llvm::Regex::Regex
Regex()
Definition: Regex.cpp:27
llvm::Regex::NoFlags
@ NoFlags
Definition: Regex.h:31
llvm::Regex::operator=
Regex & operator=(Regex regex)
Definition: Regex.h:56
llvm::Regex::isValid
bool isValid() const
Definition: Regex.h:67
error
#define error(X)
Definition: SymbolRecordMapping.cpp:14
llvm_regex
Definition: regex_impl.h:48
llvm::Regex::match
bool match(StringRef String, SmallVectorImpl< StringRef > *Matches=nullptr, std::string *Error=nullptr) const
matches - Match the regex against a given String.
Definition: Regex.cpp:86
llvm::Regex::getNumMatches
unsigned getNumMatches() const
getNumMatches - In a valid regex, return the number of parenthesized matches it contains.
Definition: Regex.cpp:82
llvm::Regex::BasicRegex
@ BasicRegex
By default, the POSIX extended regular expression (ERE) syntax is assumed.
Definition: Regex.h:43
llvm::Regex::isLiteralERE
static bool isLiteralERE(StringRef Str)
If this function returns true, ^Str$ is an extended regular expression that matches Str and only Str.
Definition: Regex.cpp:212
llvm::Regex::sub
std::string sub(StringRef Repl, StringRef String, std::string *Error=nullptr) const
sub - Return the result of replacing the first match of the regex in String with the Repl string.
Definition: Regex.cpp:136
std::swap
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:840
llvm::StringRef
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:58
BitmaskEnum.h
llvm::Regex::IgnoreCase
@ IgnoreCase
Compile for matching that ignores upper/lower case distinctions.
Definition: Regex.h:33
llvm::Regex::Newline
@ Newline
Compile for newline-sensitive matching.
Definition: Regex.h:39
llvm::Error
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
llvm::Regex::RegexFlags
RegexFlags
Definition: Regex.h:30
llvm::SmallVectorImpl< StringRef >
llvm::Regex
Definition: Regex.h:28
llvm::Regex::~Regex
~Regex()
Definition: Regex.cpp:52
llvm::Regex::escape
static std::string escape(StringRef String)
Turn String into a regex by escaping its special characters.
Definition: Regex.cpp:219