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 { 31 NoFlags=0, 32 /// Compile for matching that ignores upper/lower case distinctions. 33 IgnoreCase=1, 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. 43 BasicRegex=4 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 } Regex(Regex && regex)54 Regex(Regex &®ex) { 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 106