1 //===-- Regex.h - Regular Expression matcher implementation -*- C++ -*-----===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
15 //===----------------------------------------------------------------------===//
17 #ifndef LLVM_SUPPORT_REGEX_H
18 #define LLVM_SUPPORT_REGEX_H
20 #include "llvm/Support/Compiler.h"
27 template<typename T> class SmallVectorImpl;
33 /// Compile for matching that ignores upper/lower case distinctions.
35 /// Compile for newline-sensitive matching. With this flag '[^' bracket
36 /// expressions and '.' never match newline. A ^ anchor matches the
37 /// null string after any newline in the string in addition to its normal
38 /// function, and the $ anchor matches the null string before any
39 /// newline in the string in addition to its normal function.
41 /// By default, the POSIX extended regular expression (ERE) syntax is
42 /// assumed. Pass this flag to turn on basic regular expressions (BRE)
47 /// Compiles the given regular expression \p Regex.
48 Regex(StringRef Regex, unsigned Flags = NoFlags);
49 Regex(const Regex &) LLVM_DELETED_FUNCTION;
50 Regex &operator=(Regex regex) {
51 std::swap(preg, regex.preg);
52 std::swap(error, regex.error);
55 Regex(Regex &®ex) {
62 /// isValid - returns the error encountered during regex compilation, or
64 bool isValid(std::string &Error);
66 /// getNumMatches - In a valid regex, return the number of parenthesized
67 /// matches it contains. The number filled in by match will include this
68 /// many entries plus one for the whole regex (as element 0).
69 unsigned getNumMatches() const;
71 /// matches - Match the regex against a given \p String.
73 /// \param Matches - If given, on a successful match this will be filled in
74 /// with references to the matched group expressions (inside \p String),
75 /// the first group is always the entire pattern.
77 /// This returns true on a successful match.
78 bool match(StringRef String, SmallVectorImpl<StringRef> *Matches = nullptr);
80 /// sub - Return the result of replacing the first match of the regex in
81 /// \p String with the \p Repl string. Backreferences like "\0" in the
82 /// replacement string are replaced with the appropriate match substring.
84 /// Note that the replacement string has backslash escaping performed on
85 /// it. Invalid backreferences are ignored (replaced by empty strings).
87 /// \param Error If non-null, any errors in the substitution (invalid
88 /// backreferences, trailing backslashes) will be recorded as a non-empty
90 std::string sub(StringRef Repl, StringRef String,
91 std::string *Error = nullptr);
93 /// \brief If this function returns true, ^Str$ is an extended regular
94 /// expression that matches Str and only Str.
95 static bool isLiteralERE(StringRef Str);
97 /// \brief Turn String into a regex by escaping its special characters.
98 static std::string escape(StringRef String);
101 struct llvm_regex *preg;
106 #endif // LLVM_SUPPORT_REGEX_H