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 Regex(); 47 /// Compiles the given regular expression \p Regex. 48 Regex(StringRef Regex, unsigned Flags = NoFlags); 49 Regex(const Regex &) = delete; 50 Regex &operator=(Regex regex) { 51 std::swap(preg, regex.preg); 52 std::swap(error, regex.error); 53 return *this; 54 } 55 Regex(Regex &®ex); 56 ~Regex(); 57 58 /// isValid - returns the error encountered during regex compilation, or 59 /// matching, if any. 60 bool isValid(std::string &Error) const; 61 62 /// getNumMatches - In a valid regex, return the number of parenthesized 63 /// matches it contains. The number filled in by match will include this 64 /// many entries plus one for the whole regex (as element 0). 65 unsigned getNumMatches() const; 66 67 /// matches - Match the regex against a given \p String. 68 /// 69 /// \param Matches - If given, on a successful match this will be filled in 70 /// with references to the matched group expressions (inside \p String), 71 /// the first group is always the entire pattern. 72 /// 73 /// This returns true on a successful match. 74 bool match(StringRef String, SmallVectorImpl<StringRef> *Matches = nullptr); 75 76 /// sub - Return the result of replacing the first match of the regex in 77 /// \p String with the \p Repl string. Backreferences like "\0" in the 78 /// replacement string are replaced with the appropriate match substring. 79 /// 80 /// Note that the replacement string has backslash escaping performed on 81 /// it. Invalid backreferences are ignored (replaced by empty strings). 82 /// 83 /// \param Error If non-null, any errors in the substitution (invalid 84 /// backreferences, trailing backslashes) will be recorded as a non-empty 85 /// string. 86 std::string sub(StringRef Repl, StringRef String, 87 std::string *Error = nullptr); 88 89 /// \brief If this function returns true, ^Str$ is an extended regular 90 /// expression that matches Str and only Str. 91 static bool isLiteralERE(StringRef Str); 92 93 /// \brief Turn String into a regex by escaping its special characters. 94 static std::string escape(StringRef String); 95 96 private: 97 struct llvm_regex *preg; 98 int error; 99 }; 100 } 101 102 #endif // LLVM_SUPPORT_REGEX_H 103
