//===-- Regex.h - Regular Expression matcher implementation -*- C++ -*-----===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // This file implements a POSIX regular expression matcher. Both Basic and // Extended POSIX regular expressions (ERE) are supported. EREs were extended // to support backreferences in matches. // This implementation also supports matching strings with embedded NUL chars. // //===----------------------------------------------------------------------===// #ifndef LLVM_SUPPORT_REGEX_H #define LLVM_SUPPORT_REGEX_H #include struct llvm_regex; namespace llvm { class StringRef; template class SmallVectorImpl; class Regex { public: enum { NoFlags=0, /// Compile for matching that ignores upper/lower case distinctions. IgnoreCase=1, /// Compile for newline-sensitive matching. With this flag '[^' bracket /// expressions and '.' never match newline. A ^ anchor matches the /// null string after any newline in the string in addition to its normal /// function, and the $ anchor matches the null string before any /// newline in the string in addition to its normal function. Newline=2, /// By default, the POSIX extended regular expression (ERE) syntax is /// assumed. Pass this flag to turn on basic regular expressions (BRE) /// instead. BasicRegex=4 }; Regex(); /// Compiles the given regular expression \p Regex. /// /// \param Regex - referenced string is no longer needed after this /// constructor does finish. Only its compiled form is kept stored. Regex(StringRef Regex, unsigned Flags = NoFlags); Regex(const Regex &) = delete; Regex &operator=(Regex regex) { std::swap(preg, regex.preg); std::swap(error, regex.error); return *this; } Regex(Regex &®ex); ~Regex(); /// isValid - returns the error encountered during regex compilation, if /// any. bool isValid(std::string &Error) const; bool isValid() const { return !error; } /// getNumMatches - In a valid regex, return the number of parenthesized /// matches it contains. The number filled in by match will include this /// many entries plus one for the whole regex (as element 0). unsigned getNumMatches() const; /// matches - Match the regex against a given \p String. /// /// \param Matches - If given, on a successful match this will be filled in /// with references to the matched group expressions (inside \p String), /// the first group is always the entire pattern. /// /// \param Error - If non-null, any errors in the matching will be recorded /// as a non-empty string. If there is no error, it will be an empty string. /// /// This returns true on a successful match. bool match(StringRef String, SmallVectorImpl *Matches = nullptr, std::string *Error = nullptr) const; /// sub - Return the result of replacing the first match of the regex in /// \p String with the \p Repl string. Backreferences like "\0" in the /// replacement string are replaced with the appropriate match substring. /// /// Note that the replacement string has backslash escaping performed on /// it. Invalid backreferences are ignored (replaced by empty strings). /// /// \param Error If non-null, any errors in the substitution (invalid /// backreferences, trailing backslashes) will be recorded as a non-empty /// string. If there is no error, it will be an empty string. std::string sub(StringRef Repl, StringRef String, std::string *Error = nullptr) const; /// If this function returns true, ^Str$ is an extended regular /// expression that matches Str and only Str. static bool isLiteralERE(StringRef Str); /// Turn String into a regex by escaping its special characters. static std::string escape(StringRef String); private: struct llvm_regex *preg; int error; }; } #endif // LLVM_SUPPORT_REGEX_H