1 //===--- Marshallers.cpp ----------------------------------------*- 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 #include "Marshallers.h"
10 #include "llvm/ADT/ArrayRef.h"
11 #include "llvm/ADT/StringRef.h"
12 #include "llvm/Support/Regex.h"
13 #include <optional>
14 #include <string>
15 
16 static std::optional<std::string>
17 getBestGuess(llvm::StringRef Search, llvm::ArrayRef<llvm::StringRef> Allowed,
18              llvm::StringRef DropPrefix = "", unsigned MaxEditDistance = 3) {
19   if (MaxEditDistance != ~0U)
20     ++MaxEditDistance;
21   llvm::StringRef Res;
22   for (const llvm::StringRef &Item : Allowed) {
23     if (Item.equals_insensitive(Search)) {
24       assert(!Item.equals(Search) && "This should be handled earlier on.");
25       MaxEditDistance = 1;
26       Res = Item;
27       continue;
28     }
29     unsigned Distance = Item.edit_distance(Search);
30     if (Distance < MaxEditDistance) {
31       MaxEditDistance = Distance;
32       Res = Item;
33     }
34   }
35   if (!Res.empty())
36     return Res.str();
37   if (!DropPrefix.empty()) {
38     --MaxEditDistance; // Treat dropping the prefix as 1 edit
39     for (const llvm::StringRef &Item : Allowed) {
40       auto NoPrefix = Item;
41       if (!NoPrefix.consume_front(DropPrefix))
42         continue;
43       if (NoPrefix.equals_insensitive(Search)) {
44         if (NoPrefix.equals(Search))
45           return Item.str();
46         MaxEditDistance = 1;
47         Res = Item;
48         continue;
49       }
50       unsigned Distance = NoPrefix.edit_distance(Search);
51       if (Distance < MaxEditDistance) {
52         MaxEditDistance = Distance;
53         Res = Item;
54       }
55     }
56     if (!Res.empty())
57       return Res.str();
58   }
59   return std::nullopt;
60 }
61 
62 std::optional<std::string>
63 clang::ast_matchers::dynamic::internal::ArgTypeTraits<
64     clang::attr::Kind>::getBestGuess(const VariantValue &Value) {
65   static constexpr llvm::StringRef Allowed[] = {
66 #define ATTR(X) "attr::" #X,
67 #include "clang/Basic/AttrList.inc"
68   };
69   if (Value.isString())
70     return ::getBestGuess(Value.getString(), llvm::ArrayRef(Allowed), "attr::");
71   return std::nullopt;
72 }
73 
74 std::optional<std::string>
75 clang::ast_matchers::dynamic::internal::ArgTypeTraits<
76     clang::CastKind>::getBestGuess(const VariantValue &Value) {
77   static constexpr llvm::StringRef Allowed[] = {
78 #define CAST_OPERATION(Name) "CK_" #Name,
79 #include "clang/AST/OperationKinds.def"
80   };
81   if (Value.isString())
82     return ::getBestGuess(Value.getString(), llvm::ArrayRef(Allowed), "CK_");
83   return std::nullopt;
84 }
85 
86 std::optional<std::string>
87 clang::ast_matchers::dynamic::internal::ArgTypeTraits<
88     clang::OpenMPClauseKind>::getBestGuess(const VariantValue &Value) {
89   static constexpr llvm::StringRef Allowed[] = {
90 #define GEN_CLANG_CLAUSE_CLASS
91 #define CLAUSE_CLASS(Enum, Str, Class) #Enum,
92 #include "llvm/Frontend/OpenMP/OMP.inc"
93   };
94   if (Value.isString())
95     return ::getBestGuess(Value.getString(), llvm::ArrayRef(Allowed), "OMPC_");
96   return std::nullopt;
97 }
98 
99 std::optional<std::string>
100 clang::ast_matchers::dynamic::internal::ArgTypeTraits<
101     clang::UnaryExprOrTypeTrait>::getBestGuess(const VariantValue &Value) {
102   static constexpr llvm::StringRef Allowed[] = {
103 #define UNARY_EXPR_OR_TYPE_TRAIT(Spelling, Name, Key) "UETT_" #Name,
104 #define CXX11_UNARY_EXPR_OR_TYPE_TRAIT(Spelling, Name, Key) "UETT_" #Name,
105 #include "clang/Basic/TokenKinds.def"
106   };
107   if (Value.isString())
108     return ::getBestGuess(Value.getString(), llvm::ArrayRef(Allowed), "UETT_");
109   return std::nullopt;
110 }
111 
112 static constexpr std::pair<llvm::StringRef, llvm::Regex::RegexFlags>
113     RegexMap[] = {
114         {"NoFlags", llvm::Regex::RegexFlags::NoFlags},
115         {"IgnoreCase", llvm::Regex::RegexFlags::IgnoreCase},
116         {"Newline", llvm::Regex::RegexFlags::Newline},
117         {"BasicRegex", llvm::Regex::RegexFlags::BasicRegex},
118 };
119 
120 static std::optional<llvm::Regex::RegexFlags>
121 getRegexFlag(llvm::StringRef Flag) {
122   for (const auto &StringFlag : RegexMap) {
123     if (Flag == StringFlag.first)
124       return StringFlag.second;
125   }
126   return std::nullopt;
127 }
128 
129 static std::optional<llvm::StringRef> getCloseRegexMatch(llvm::StringRef Flag) {
130   for (const auto &StringFlag : RegexMap) {
131     if (Flag.edit_distance(StringFlag.first) < 3)
132       return StringFlag.first;
133   }
134   return std::nullopt;
135 }
136 
137 std::optional<llvm::Regex::RegexFlags>
138 clang::ast_matchers::dynamic::internal::ArgTypeTraits<
139     llvm::Regex::RegexFlags>::getFlags(llvm::StringRef Flags) {
140   std::optional<llvm::Regex::RegexFlags> Flag;
141   SmallVector<StringRef, 4> Split;
142   Flags.split(Split, '|', -1, false);
143   for (StringRef OrFlag : Split) {
144     if (std::optional<llvm::Regex::RegexFlags> NextFlag =
145             getRegexFlag(OrFlag.trim()))
146       Flag = Flag.value_or(llvm::Regex::NoFlags) | *NextFlag;
147     else
148       return std::nullopt;
149   }
150   return Flag;
151 }
152 
153 std::optional<std::string>
154 clang::ast_matchers::dynamic::internal::ArgTypeTraits<
155     llvm::Regex::RegexFlags>::getBestGuess(const VariantValue &Value) {
156   if (!Value.isString())
157     return std::nullopt;
158   SmallVector<StringRef, 4> Split;
159   llvm::StringRef(Value.getString()).split(Split, '|', -1, false);
160   for (llvm::StringRef &Flag : Split) {
161     if (std::optional<llvm::StringRef> BestGuess =
162             getCloseRegexMatch(Flag.trim()))
163       Flag = *BestGuess;
164     else
165       return std::nullopt;
166   }
167   if (Split.empty())
168     return std::nullopt;
169   return llvm::join(Split, " | ");
170 }
171