xref: /llvm-project/clang/lib/Basic/Attributes.cpp (revision 4018317407006b2c632fbb75729de624a2426439)
1 //===--- Attributes.cpp ---------------------------------------------------===//
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 AttributeCommonInfo interface.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/Basic/Attributes.h"
14 #include "clang/Basic/AttrSubjectMatchRules.h"
15 #include "clang/Basic/IdentifierTable.h"
16 #include "clang/Basic/LangOptions.h"
17 #include "clang/Basic/ParsedAttrInfo.h"
18 #include "clang/Basic/TargetInfo.h"
19 
20 #include "llvm/ADT/StringMap.h"
21 #include "llvm/ADT/StringSwitch.h"
22 
23 using namespace clang;
24 
25 static int hasAttributeImpl(AttributeCommonInfo::Syntax Syntax, StringRef Name,
26                             StringRef ScopeName, const TargetInfo &Target,
27                             const LangOptions &LangOpts) {
28 
29 #include "clang/Basic/AttrHasAttributeImpl.inc"
30 
31   return 0;
32 }
33 
34 int clang::hasAttribute(AttributeCommonInfo::Syntax Syntax,
35                         const IdentifierInfo *Scope, const IdentifierInfo *Attr,
36                         const TargetInfo &Target, const LangOptions &LangOpts,
37                         bool CheckPlugins) {
38   StringRef Name = Attr->getName();
39   // Normalize the attribute name, __foo__ becomes foo.
40   if (Name.size() >= 4 && Name.starts_with("__") && Name.ends_with("__"))
41     Name = Name.substr(2, Name.size() - 4);
42 
43   // Normalize the scope name, but only for gnu and clang attributes.
44   StringRef ScopeName = Scope ? Scope->getName() : "";
45   if (ScopeName == "__gnu__")
46     ScopeName = "gnu";
47   else if (ScopeName == "_Clang")
48     ScopeName = "clang";
49 
50   // As a special case, look for the omp::sequence and omp::directive
51   // attributes. We support those, but not through the typical attribute
52   // machinery that goes through TableGen. We support this in all OpenMP modes
53   // so long as double square brackets are enabled.
54   //
55   // Other OpenMP attributes (e.g. [[omp::assume]]) are handled via the
56   // regular attribute parsing machinery.
57   if (LangOpts.OpenMP && ScopeName == "omp" &&
58       (Name == "directive" || Name == "sequence"))
59     return 1;
60 
61   int res = hasAttributeImpl(Syntax, Name, ScopeName, Target, LangOpts);
62   if (res)
63     return res;
64 
65   if (CheckPlugins) {
66     // Check if any plugin provides this attribute.
67     for (auto &Ptr : getAttributePluginInstances())
68       if (Ptr->hasSpelling(Syntax, Name))
69         return 1;
70   }
71 
72   return 0;
73 }
74 
75 int clang::hasAttribute(AttributeCommonInfo::Syntax Syntax,
76                         const IdentifierInfo *Scope, const IdentifierInfo *Attr,
77                         const TargetInfo &Target, const LangOptions &LangOpts) {
78   return hasAttribute(Syntax, Scope, Attr, Target, LangOpts,
79                       /*CheckPlugins=*/true);
80 }
81 
82 const char *attr::getSubjectMatchRuleSpelling(attr::SubjectMatchRule Rule) {
83   switch (Rule) {
84 #define ATTR_MATCH_RULE(NAME, SPELLING, IsAbstract)                            \
85   case attr::NAME:                                                             \
86     return SPELLING;
87 #include "clang/Basic/AttrSubMatchRulesList.inc"
88   }
89   llvm_unreachable("Invalid subject match rule");
90 }
91 
92 static StringRef
93 normalizeAttrScopeName(const IdentifierInfo *Scope,
94                        AttributeCommonInfo::Syntax SyntaxUsed) {
95   if (!Scope)
96     return "";
97 
98   // Normalize the "__gnu__" scope name to be "gnu" and the "_Clang" scope name
99   // to be "clang".
100   StringRef ScopeName = Scope->getName();
101   if (SyntaxUsed == AttributeCommonInfo::AS_CXX11 ||
102       SyntaxUsed == AttributeCommonInfo::AS_C23) {
103     if (ScopeName == "__gnu__")
104       ScopeName = "gnu";
105     else if (ScopeName == "_Clang")
106       ScopeName = "clang";
107   }
108   return ScopeName;
109 }
110 
111 static StringRef normalizeAttrName(const IdentifierInfo *Name,
112                                    StringRef NormalizedScopeName,
113                                    AttributeCommonInfo::Syntax SyntaxUsed) {
114   // Normalize the attribute name, __foo__ becomes foo. This is only allowable
115   // for GNU attributes, and attributes using the double square bracket syntax.
116   bool ShouldNormalize =
117       SyntaxUsed == AttributeCommonInfo::AS_GNU ||
118       ((SyntaxUsed == AttributeCommonInfo::AS_CXX11 ||
119         SyntaxUsed == AttributeCommonInfo::AS_C23) &&
120        (NormalizedScopeName.empty() || NormalizedScopeName == "gnu" ||
121         NormalizedScopeName == "clang"));
122   StringRef AttrName = Name->getName();
123   if (ShouldNormalize && AttrName.size() >= 4 && AttrName.starts_with("__") &&
124       AttrName.ends_with("__"))
125     AttrName = AttrName.slice(2, AttrName.size() - 2);
126 
127   return AttrName;
128 }
129 
130 bool AttributeCommonInfo::isGNUScope() const {
131   return ScopeName && (ScopeName->isStr("gnu") || ScopeName->isStr("__gnu__"));
132 }
133 
134 bool AttributeCommonInfo::isClangScope() const {
135   return ScopeName && (ScopeName->isStr("clang") || ScopeName->isStr("_Clang"));
136 }
137 
138 #include "clang/Sema/AttrParsedAttrKinds.inc"
139 
140 static SmallString<64> normalizeName(const IdentifierInfo *Name,
141                                      const IdentifierInfo *Scope,
142                                      AttributeCommonInfo::Syntax SyntaxUsed) {
143   StringRef ScopeName = normalizeAttrScopeName(Scope, SyntaxUsed);
144   StringRef AttrName = normalizeAttrName(Name, ScopeName, SyntaxUsed);
145 
146   SmallString<64> FullName = ScopeName;
147   if (!ScopeName.empty()) {
148     assert(SyntaxUsed == AttributeCommonInfo::AS_CXX11 ||
149            SyntaxUsed == AttributeCommonInfo::AS_C23);
150     FullName += "::";
151   }
152   FullName += AttrName;
153 
154   return FullName;
155 }
156 
157 AttributeCommonInfo::Kind
158 AttributeCommonInfo::getParsedKind(const IdentifierInfo *Name,
159                                    const IdentifierInfo *ScopeName,
160                                    Syntax SyntaxUsed) {
161   return ::getAttrKind(normalizeName(Name, ScopeName, SyntaxUsed), SyntaxUsed);
162 }
163 
164 AttributeCommonInfo::AttrArgsInfo
165 AttributeCommonInfo::getCXX11AttrArgsInfo(const IdentifierInfo *Name) {
166   StringRef AttrName =
167       normalizeAttrName(Name, /*NormalizedScopeName*/ "", Syntax::AS_CXX11);
168 #define CXX11_ATTR_ARGS_INFO
169   return llvm::StringSwitch<AttributeCommonInfo::AttrArgsInfo>(AttrName)
170 #include "clang/Basic/CXX11AttributeInfo.inc"
171       .Default(AttributeCommonInfo::AttrArgsInfo::None);
172 #undef CXX11_ATTR_ARGS_INFO
173 }
174 
175 std::string AttributeCommonInfo::getNormalizedFullName() const {
176   return static_cast<std::string>(
177       normalizeName(getAttrName(), getScopeName(), getSyntax()));
178 }
179 
180 static AttributeCommonInfo::Scope
181 getScopeFromNormalizedScopeName(StringRef ScopeName) {
182   return llvm::StringSwitch<AttributeCommonInfo::Scope>(ScopeName)
183       .Case("", AttributeCommonInfo::Scope::NONE)
184       .Case("clang", AttributeCommonInfo::Scope::CLANG)
185       .Case("gnu", AttributeCommonInfo::Scope::GNU)
186       .Case("gsl", AttributeCommonInfo::Scope::GSL)
187       .Case("hlsl", AttributeCommonInfo::Scope::HLSL)
188       .Case("msvc", AttributeCommonInfo::Scope::MSVC)
189       .Case("omp", AttributeCommonInfo::Scope::OMP)
190       .Case("riscv", AttributeCommonInfo::Scope::RISCV);
191 }
192 
193 unsigned AttributeCommonInfo::calculateAttributeSpellingListIndex() const {
194   // Both variables will be used in tablegen generated
195   // attribute spell list index matching code.
196   auto Syntax = static_cast<AttributeCommonInfo::Syntax>(getSyntax());
197   StringRef ScopeName = normalizeAttrScopeName(getScopeName(), Syntax);
198   StringRef Name = normalizeAttrName(getAttrName(), ScopeName, Syntax);
199 
200   AttributeCommonInfo::Scope ComputedScope =
201       getScopeFromNormalizedScopeName(ScopeName);
202 
203 #include "clang/Sema/AttrSpellingListIndex.inc"
204 }
205