include/llvm/TableGen/StringMatcher.h

   1 //===- StringMatcher.h - Generate a matcher for input strings ---*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the StringMatcher class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_TABLEGEN_STRINGMATCHER_H
  14 #define LLVM_TABLEGEN_STRINGMATCHER_H
  15
  16 #include "llvm/ADT/StringRef.h"
  17 #include <string>
  18 #include <utility>
  19 #include <vector>
  20
  21 namespace llvm {
  22
  23 class raw_ostream;
  24
  25 /// Given a list of strings and code to execute when they match, output a
  26 /// simple switch tree to classify the input string.
  27 ///
  28 /// If a match is found, the code in Matches[i].second is executed; control must
  29 /// not exit this code fragment.  If nothing matches, execution falls through.
  30 class StringMatcher {
  31 public:
  32   using StringPair = std::pair<std::string, std::string>;
  33
  34 private:
  35   StringRef StrVariableName;
  36   const std::vector<StringPair> &Matches;
  37   raw_ostream &OS;
  38
  39 public:
  40   StringMatcher(StringRef strVariableName,
  41                 const std::vector<StringPair> &matches, raw_ostream &os)
  42     : StrVariableName(strVariableName), Matches(matches), OS(os) {}
  43
  44   void Emit(unsigned Indent = 0, bool IgnoreDuplicates = false) const;
  45
  46 private:
  47   bool EmitStringMatcherForChar(const std::vector<const StringPair *> &Matches,
  48                                 unsigned CharNo, unsigned IndentCount,
  49                                 bool IgnoreDuplicates) const;
  50 };
  51
  52 } // end namespace llvm
  53
  54 #endif // LLVM_TABLEGEN_STRINGMATCHER_H