clang  15.0.0git
BuiltinTargetFeatures.h
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1 //===-- CodeGenFunction.h - Target features for builtin ---------*- 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 is the internal required target features for builtin.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_LIB_BASIC_BUILTINTARGETFEATURES_H
14 #define LLVM_CLANG_LIB_BASIC_BUILTINTARGETFEATURES_H
15 #include "llvm/ADT/StringMap.h"
16 #include "llvm/ADT/StringRef.h"
17 
18 using llvm::StringRef;
19 
20 namespace clang {
21 namespace Builtin {
22 /// TargetFeatures - This class is used to check whether the builtin function
23 /// has the required tagert specific features. It is able to support the
24 /// combination of ','(and), '|'(or), and '()'. By default, the priority of
25 /// ',' is higher than that of '|' .
26 /// E.g:
27 /// A,B|C means the builtin function requires both A and B, or C.
28 /// If we want the builtin function requires both A and B, or both A and C,
29 /// there are two ways: A,B|A,C or A,(B|C).
30 /// The FeaturesList should not contain spaces, and brackets must appear in
31 /// pairs.
33  struct FeatureListStatus {
34  bool HasFeatures;
35  StringRef CurFeaturesList;
36  };
37 
38  const llvm::StringMap<bool> &CallerFeatureMap;
39 
40  FeatureListStatus getAndFeatures(StringRef FeatureList) {
41  int InParentheses = 0;
42  bool HasFeatures = true;
43  size_t SubexpressionStart = 0;
44  for (size_t i = 0, e = FeatureList.size(); i < e; ++i) {
45  char CurrentToken = FeatureList[i];
46  switch (CurrentToken) {
47  default:
48  break;
49  case '(':
50  if (InParentheses == 0)
51  SubexpressionStart = i + 1;
52  ++InParentheses;
53  break;
54  case ')':
55  --InParentheses;
56  assert(InParentheses >= 0 && "Parentheses are not in pair");
57  LLVM_FALLTHROUGH;
58  case '|':
59  case ',':
60  if (InParentheses == 0) {
61  if (HasFeatures && i != SubexpressionStart) {
62  StringRef F = FeatureList.slice(SubexpressionStart, i);
63  HasFeatures = CurrentToken == ')' ? hasRequiredFeatures(F)
64  : CallerFeatureMap.lookup(F);
65  }
66  SubexpressionStart = i + 1;
67  if (CurrentToken == '|') {
68  return {HasFeatures, FeatureList.substr(SubexpressionStart)};
69  }
70  }
71  break;
72  }
73  }
74  assert(InParentheses == 0 && "Parentheses are not in pair");
75  if (HasFeatures && SubexpressionStart != FeatureList.size())
76  HasFeatures =
77  CallerFeatureMap.lookup(FeatureList.substr(SubexpressionStart));
78  return {HasFeatures, StringRef()};
79  }
80 
81 public:
82  bool hasRequiredFeatures(StringRef FeatureList) {
83  FeatureListStatus FS = {false, FeatureList};
84  while (!FS.HasFeatures && !FS.CurFeaturesList.empty())
85  FS = getAndFeatures(FS.CurFeaturesList);
86  return FS.HasFeatures;
87  }
88 
89  TargetFeatures(const llvm::StringMap<bool> &CallerFeatureMap)
90  : CallerFeatureMap(CallerFeatureMap) {}
91 };
92 
93 } // namespace Builtin
94 } // namespace clang
95 #endif /* CLANG_LIB_BASIC_BUILTINTARGETFEATURES_H */
clang::Builtin::TargetFeatures
TargetFeatures - This class is used to check whether the builtin function has the required tagert spe...
Definition: BuiltinTargetFeatures.h:32
clang::Builtin::TargetFeatures::hasRequiredFeatures
bool hasRequiredFeatures(StringRef FeatureList)
Definition: BuiltinTargetFeatures.h:82
clang::Builtin::TargetFeatures::TargetFeatures
TargetFeatures(const llvm::StringMap< bool > &CallerFeatureMap)
Definition: BuiltinTargetFeatures.h:89
clang
Definition: CalledOnceCheck.h:17