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:
StringMatcher(StringRef strVariableName,const std::vector<StringPair> & matches,raw_ostream & os)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
55