LLVM  3.7.0
Regex.h
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1 //===-- Regex.h - Regular Expression matcher implementation -*- C++ -*-----===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements a POSIX regular expression matcher. Both Basic and
11 // Extended POSIX regular expressions (ERE) are supported. EREs were extended
12 // to support backreferences in matches.
13 // This implementation also supports matching strings with embedded NUL chars.
14 //
15 //===----------------------------------------------------------------------===//
16 
17 #ifndef LLVM_SUPPORT_REGEX_H
18 #define LLVM_SUPPORT_REGEX_H
19 
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 {
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.
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  };
45 
46  /// Compiles the given regular expression \p Regex.
47  Regex(StringRef Regex, unsigned Flags = NoFlags);
48  Regex(const Regex &) = delete;
49  Regex &operator=(Regex regex) {
50  std::swap(preg, regex.preg);
51  std::swap(error, regex.error);
52  return *this;
53  }
54  Regex(Regex &&regex) {
55  preg = regex.preg;
56  error = regex.error;
57  regex.preg = nullptr;
58  }
59  ~Regex();
60 
61  /// isValid - returns the error encountered during regex compilation, or
62  /// matching, if any.
63  bool isValid(std::string &Error);
64 
65  /// getNumMatches - In a valid regex, return the number of parenthesized
66  /// matches it contains. The number filled in by match will include this
67  /// many entries plus one for the whole regex (as element 0).
68  unsigned getNumMatches() const;
69 
70  /// matches - Match the regex against a given \p String.
71  ///
72  /// \param Matches - If given, on a successful match this will be filled in
73  /// with references to the matched group expressions (inside \p String),
74  /// the first group is always the entire pattern.
75  ///
76  /// This returns true on a successful match.
77  bool match(StringRef String, SmallVectorImpl<StringRef> *Matches = nullptr);
78 
79  /// sub - Return the result of replacing the first match of the regex in
80  /// \p String with the \p Repl string. Backreferences like "\0" in the
81  /// replacement string are replaced with the appropriate match substring.
82  ///
83  /// Note that the replacement string has backslash escaping performed on
84  /// it. Invalid backreferences are ignored (replaced by empty strings).
85  ///
86  /// \param Error If non-null, any errors in the substitution (invalid
87  /// backreferences, trailing backslashes) will be recorded as a non-empty
88  /// string.
89  std::string sub(StringRef Repl, StringRef String,
90  std::string *Error = nullptr);
91 
92  /// \brief If this function returns true, ^Str$ is an extended regular
93  /// expression that matches Str and only Str.
94  static bool isLiteralERE(StringRef Str);
95 
96  /// \brief Turn String into a regex by escaping its special characters.
97  static std::string escape(StringRef String);
98 
99  private:
100  struct llvm_regex *preg;
101  int error;
102  };
103 }
104 
105 #endif // LLVM_SUPPORT_REGEX_H
static std::string escape(StringRef String)
Turn String into a regex by escaping its special characters.
Definition: Regex.cpp:184
By default, the POSIX extended regular expression (ERE) syntax is assumed.
Definition: Regex.h:43
bool isValid(std::string &Error)
isValid - returns the error encountered during regex compilation, or matching, if any...
Definition: Regex.cpp:42
static std::error_code error(DiagnosticHandlerFunction DiagnosticHandler, std::error_code EC, const Twine &Message)
Compile for newline-sensitive matching.
Definition: Regex.h:39
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:177
std::string sub(StringRef Repl, StringRef String, std::string *Error=nullptr)
sub - Return the result of replacing the first match of the regex in String with the Repl string...
Definition: Regex.cpp:98
unsigned getNumMatches() const
getNumMatches - In a valid regex, return the number of parenthesized matches it contains.
Definition: Regex.cpp:55
Regex & operator=(Regex regex)
Definition: Regex.h:49
Regex(StringRef Regex, unsigned Flags=NoFlags)
Compiles the given regular expression Regex.
Definition: Regex.cpp:22
Regex(Regex &&regex)
Definition: Regex.h:54
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:576
Compile for matching that ignores upper/lower case distinctions.
Definition: Regex.h:33
bool match(StringRef String, SmallVectorImpl< StringRef > *Matches=nullptr)
matches - Match the regex against a given String.
Definition: Regex.cpp:59
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:40