StringMatcher.h

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//===- StringMatcher.h - Generate a matcher for input strings ---*- 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 the StringMatcher class.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_TABLEGEN_STRINGMATCHER_H
#define LLVM_TABLEGEN_STRINGMATCHER_H
 
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include <string>
#include <utility>
 
namespace llvm {
 
class raw_ostream;
 
/// Given a list of strings and code to execute when they match, output a
/// simple switch tree to classify the input string.
///
/// If a match is found, the code in Matches[i].second is executed; control must
/// not exit this code fragment. If nothing matches, execution falls through.
class StringMatcher {
public:
  using StringPair = std::pair<std::string, std::string>;
 
private:
  StringRef StrVariableName;
  ArrayRef<StringPair> Matches;
  raw_ostream &OS;
 
public:
  StringMatcher(StringRef StrVariableName, ArrayRef<StringPair> Matches,
                raw_ostream &OS)
      : StrVariableName(StrVariableName), Matches(Matches), OS(OS) {}
 
  void Emit(unsigned Indent = 0, bool IgnoreDuplicates = false) const;
 
private:
  bool EmitStringMatcherForChar(ArrayRef<const StringPair *> Matches,
                                unsigned CharNo, unsigned IndentCount,
                                bool IgnoreDuplicates) const;
};
 
} // end namespace llvm
 
#endif // LLVM_TABLEGEN_STRINGMATCHER_H