xref: /freebsd/contrib/llvm-project/clang/lib/Basic/Attributes.cpp (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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 using namespace clang;
21 
22 static int hasAttributeImpl(AttributeCommonInfo::Syntax Syntax, StringRef Name,
23                             StringRef ScopeName, const TargetInfo &Target,
24                             const LangOptions &LangOpts) {
25 
26 #include "clang/Basic/AttrHasAttributeImpl.inc"
27 
28   return 0;
29 }
30 
31 int clang::hasAttribute(AttributeCommonInfo::Syntax Syntax,
32                         const IdentifierInfo *Scope, const IdentifierInfo *Attr,
33                         const TargetInfo &Target, const LangOptions &LangOpts) {
34   StringRef Name = Attr->getName();
35   // Normalize the attribute name, __foo__ becomes foo.
36   if (Name.size() >= 4 && Name.starts_with("__") && Name.ends_with("__"))
37     Name = Name.substr(2, Name.size() - 4);
38 
39   // Normalize the scope name, but only for gnu and clang attributes.
40   StringRef ScopeName = Scope ? Scope->getName() : "";
41   if (ScopeName == "__gnu__")
42     ScopeName = "gnu";
43   else if (ScopeName == "_Clang")
44     ScopeName = "clang";
45 
46   // As a special case, look for the omp::sequence and omp::directive
47   // attributes. We support those, but not through the typical attribute
48   // machinery that goes through TableGen. We support this in all OpenMP modes
49   // so long as double square brackets are enabled.
50   //
51   // Other OpenMP attributes (e.g. [[omp::assume]]) are handled via the
52   // regular attribute parsing machinery.
53   if (LangOpts.OpenMP && ScopeName == "omp" &&
54       (Name == "directive" || Name == "sequence"))
55     return 1;
56 
57   int res = hasAttributeImpl(Syntax, Name, ScopeName, Target, LangOpts);
58   if (res)
59     return res;
60 
61   // Check if any plugin provides this attribute.
62   for (auto &Ptr : getAttributePluginInstances())
63     if (Ptr->hasSpelling(Syntax, Name))
64       return 1;
65 
66   return 0;
67 }
68 
69 const char *attr::getSubjectMatchRuleSpelling(attr::SubjectMatchRule Rule) {
70   switch (Rule) {
71 #define ATTR_MATCH_RULE(NAME, SPELLING, IsAbstract)                            \
72   case attr::NAME:                                                             \
73     return SPELLING;
74 #include "clang/Basic/AttrSubMatchRulesList.inc"
75   }
76   llvm_unreachable("Invalid subject match rule");
77 }
78 
79 static StringRef
80 normalizeAttrScopeName(const IdentifierInfo *Scope,
81                        AttributeCommonInfo::Syntax SyntaxUsed) {
82   if (!Scope)
83     return "";
84 
85   // Normalize the "__gnu__" scope name to be "gnu" and the "_Clang" scope name
86   // to be "clang".
87   StringRef ScopeName = Scope->getName();
88   if (SyntaxUsed == AttributeCommonInfo::AS_CXX11 ||
89       SyntaxUsed == AttributeCommonInfo::AS_C23) {
90     if (ScopeName == "__gnu__")
91       ScopeName = "gnu";
92     else if (ScopeName == "_Clang")
93       ScopeName = "clang";
94   }
95   return ScopeName;
96 }
97 
98 static StringRef normalizeAttrName(const IdentifierInfo *Name,
99                                    StringRef NormalizedScopeName,
100                                    AttributeCommonInfo::Syntax SyntaxUsed) {
101   // Normalize the attribute name, __foo__ becomes foo. This is only allowable
102   // for GNU attributes, and attributes using the double square bracket syntax.
103   bool ShouldNormalize =
104       SyntaxUsed == AttributeCommonInfo::AS_GNU ||
105       ((SyntaxUsed == AttributeCommonInfo::AS_CXX11 ||
106         SyntaxUsed == AttributeCommonInfo::AS_C23) &&
107        (NormalizedScopeName.empty() || NormalizedScopeName == "gnu" ||
108         NormalizedScopeName == "clang"));
109   StringRef AttrName = Name->getName();
110   if (ShouldNormalize && AttrName.size() >= 4 && AttrName.starts_with("__") &&
111       AttrName.ends_with("__"))
112     AttrName = AttrName.slice(2, AttrName.size() - 2);
113 
114   return AttrName;
115 }
116 
117 bool AttributeCommonInfo::isGNUScope() const {
118   return ScopeName && (ScopeName->isStr("gnu") || ScopeName->isStr("__gnu__"));
119 }
120 
121 bool AttributeCommonInfo::isClangScope() const {
122   return ScopeName && (ScopeName->isStr("clang") || ScopeName->isStr("_Clang"));
123 }
124 
125 #include "clang/Sema/AttrParsedAttrKinds.inc"
126 
127 static SmallString<64> normalizeName(const IdentifierInfo *Name,
128                                      const IdentifierInfo *Scope,
129                                      AttributeCommonInfo::Syntax SyntaxUsed) {
130   StringRef ScopeName = normalizeAttrScopeName(Scope, SyntaxUsed);
131   StringRef AttrName = normalizeAttrName(Name, ScopeName, SyntaxUsed);
132 
133   SmallString<64> FullName = ScopeName;
134   if (!ScopeName.empty()) {
135     assert(SyntaxUsed == AttributeCommonInfo::AS_CXX11 ||
136            SyntaxUsed == AttributeCommonInfo::AS_C23);
137     FullName += "::";
138   }
139   FullName += AttrName;
140 
141   return FullName;
142 }
143 
144 AttributeCommonInfo::Kind
145 AttributeCommonInfo::getParsedKind(const IdentifierInfo *Name,
146                                    const IdentifierInfo *ScopeName,
147                                    Syntax SyntaxUsed) {
148   return ::getAttrKind(normalizeName(Name, ScopeName, SyntaxUsed), SyntaxUsed);
149 }
150 
151 std::string AttributeCommonInfo::getNormalizedFullName() const {
152   return static_cast<std::string>(
153       normalizeName(getAttrName(), getScopeName(), getSyntax()));
154 }
155 
156 unsigned AttributeCommonInfo::calculateAttributeSpellingListIndex() const {
157   // Both variables will be used in tablegen generated
158   // attribute spell list index matching code.
159   auto Syntax = static_cast<AttributeCommonInfo::Syntax>(getSyntax());
160   StringRef Scope = normalizeAttrScopeName(getScopeName(), Syntax);
161   StringRef Name = normalizeAttrName(getAttrName(), Scope, Syntax);
162 
163 #include "clang/Sema/AttrSpellingListIndex.inc"
164 }
165