1 //===--- AttributeList.cpp --------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the AttributeList class implementation
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Sema/AttributeList.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/DeclCXX.h"
17 #include "clang/AST/DeclTemplate.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/Basic/IdentifierTable.h"
20 #include "clang/Basic/TargetInfo.h"
21 #include "clang/Sema/SemaInternal.h"
22 #include "llvm/ADT/SmallString.h"
23 #include "llvm/ADT/StringSwitch.h"
24 using namespace clang;
25 
create(ASTContext & Ctx,SourceLocation Loc,IdentifierInfo * Ident)26 IdentifierLoc *IdentifierLoc::create(ASTContext &Ctx, SourceLocation Loc,
27                                      IdentifierInfo *Ident) {
28   IdentifierLoc *Result = new (Ctx) IdentifierLoc;
29   Result->Loc = Loc;
30   Result->Ident = Ident;
31   return Result;
32 }
33 
allocated_size() const34 size_t AttributeList::allocated_size() const {
35   if (IsAvailability) return AttributeFactory::AvailabilityAllocSize;
36   else if (IsTypeTagForDatatype)
37     return AttributeFactory::TypeTagForDatatypeAllocSize;
38   else if (IsProperty)
39     return AttributeFactory::PropertyAllocSize;
40   return (sizeof(AttributeList) + NumArgs * sizeof(ArgsUnion));
41 }
42 
AttributeFactory()43 AttributeFactory::AttributeFactory() {
44   // Go ahead and configure all the inline capacity.  This is just a memset.
45   FreeLists.resize(InlineFreeListsCapacity);
46 }
~AttributeFactory()47 AttributeFactory::~AttributeFactory() {}
48 
getFreeListIndexForSize(size_t size)49 static size_t getFreeListIndexForSize(size_t size) {
50   assert(size >= sizeof(AttributeList));
51   assert((size % sizeof(void*)) == 0);
52   return ((size - sizeof(AttributeList)) / sizeof(void*));
53 }
54 
allocate(size_t size)55 void *AttributeFactory::allocate(size_t size) {
56   // Check for a previously reclaimed attribute.
57   size_t index = getFreeListIndexForSize(size);
58   if (index < FreeLists.size()) {
59     if (AttributeList *attr = FreeLists[index]) {
60       FreeLists[index] = attr->NextInPool;
61       return attr;
62     }
63   }
64 
65   // Otherwise, allocate something new.
66   return Alloc.Allocate(size, llvm::AlignOf<AttributeFactory>::Alignment);
67 }
68 
reclaimPool(AttributeList * cur)69 void AttributeFactory::reclaimPool(AttributeList *cur) {
70   assert(cur && "reclaiming empty pool!");
71   do {
72     // Read this here, because we're going to overwrite NextInPool
73     // when we toss 'cur' into the appropriate queue.
74     AttributeList *next = cur->NextInPool;
75 
76     size_t size = cur->allocated_size();
77     size_t freeListIndex = getFreeListIndexForSize(size);
78 
79     // Expand FreeLists to the appropriate size, if required.
80     if (freeListIndex >= FreeLists.size())
81       FreeLists.resize(freeListIndex+1);
82 
83     // Add 'cur' to the appropriate free-list.
84     cur->NextInPool = FreeLists[freeListIndex];
85     FreeLists[freeListIndex] = cur;
86 
87     cur = next;
88   } while (cur);
89 }
90 
takePool(AttributeList * pool)91 void AttributePool::takePool(AttributeList *pool) {
92   assert(pool);
93 
94   // Fast path:  this pool is empty.
95   if (!Head) {
96     Head = pool;
97     return;
98   }
99 
100   // Reverse the pool onto the current head.  This optimizes for the
101   // pattern of pulling a lot of pools into a single pool.
102   do {
103     AttributeList *next = pool->NextInPool;
104     pool->NextInPool = Head;
105     Head = pool;
106     pool = next;
107   } while (pool);
108 }
109 
110 #include "clang/Sema/AttrParsedAttrKinds.inc"
111 
normalizeAttrName(StringRef AttrName,StringRef ScopeName,AttributeList::Syntax SyntaxUsed)112 static StringRef normalizeAttrName(StringRef AttrName, StringRef ScopeName,
113                                    AttributeList::Syntax SyntaxUsed) {
114   // Normalize the attribute name, __foo__ becomes foo. This is only allowable
115   // for GNU attributes.
116   bool IsGNU = SyntaxUsed == AttributeList::AS_GNU ||
117                (SyntaxUsed == AttributeList::AS_CXX11 && ScopeName == "gnu");
118   if (IsGNU && AttrName.size() >= 4 && AttrName.startswith("__") &&
119       AttrName.endswith("__"))
120     AttrName = AttrName.slice(2, AttrName.size() - 2);
121 
122   return AttrName;
123 }
124 
getKind(const IdentifierInfo * Name,const IdentifierInfo * ScopeName,Syntax SyntaxUsed)125 AttributeList::Kind AttributeList::getKind(const IdentifierInfo *Name,
126                                            const IdentifierInfo *ScopeName,
127                                            Syntax SyntaxUsed) {
128   StringRef AttrName = Name->getName();
129 
130   SmallString<64> FullName;
131   if (ScopeName)
132     FullName += ScopeName->getName();
133 
134   AttrName = normalizeAttrName(AttrName, FullName, SyntaxUsed);
135 
136   // Ensure that in the case of C++11 attributes, we look for '::foo' if it is
137   // unscoped.
138   if (ScopeName || SyntaxUsed == AS_CXX11)
139     FullName += "::";
140   FullName += AttrName;
141 
142   return ::getAttrKind(FullName, SyntaxUsed);
143 }
144 
getAttributeSpellingListIndex() const145 unsigned AttributeList::getAttributeSpellingListIndex() const {
146   // Both variables will be used in tablegen generated
147   // attribute spell list index matching code.
148   StringRef Scope = ScopeName ? ScopeName->getName() : "";
149   StringRef Name = normalizeAttrName(AttrName->getName(), Scope,
150                                      (AttributeList::Syntax)SyntaxUsed);
151 
152 #include "clang/Sema/AttrSpellingListIndex.inc"
153 
154 }
155 
156 struct ParsedAttrInfo {
157   unsigned NumArgs : 4;
158   unsigned OptArgs : 4;
159   unsigned HasCustomParsing : 1;
160   unsigned IsTargetSpecific : 1;
161   unsigned IsType : 1;
162   unsigned IsKnownToGCC : 1;
163 
164   bool (*DiagAppertainsToDecl)(Sema &S, const AttributeList &Attr,
165                                const Decl *);
166   bool (*DiagLangOpts)(Sema &S, const AttributeList &Attr);
167   bool (*ExistsInTarget)(const TargetInfo &Target);
168   unsigned (*SpellingIndexToSemanticSpelling)(const AttributeList &Attr);
169 };
170 
171 namespace {
172   #include "clang/Sema/AttrParsedAttrImpl.inc"
173 }
174 
getInfo(const AttributeList & A)175 static const ParsedAttrInfo &getInfo(const AttributeList &A) {
176   return AttrInfoMap[A.getKind()];
177 }
178 
getMinArgs() const179 unsigned AttributeList::getMinArgs() const {
180   return getInfo(*this).NumArgs;
181 }
182 
getMaxArgs() const183 unsigned AttributeList::getMaxArgs() const {
184   return getMinArgs() + getInfo(*this).OptArgs;
185 }
186 
hasCustomParsing() const187 bool AttributeList::hasCustomParsing() const {
188   return getInfo(*this).HasCustomParsing;
189 }
190 
diagnoseAppertainsTo(Sema & S,const Decl * D) const191 bool AttributeList::diagnoseAppertainsTo(Sema &S, const Decl *D) const {
192   return getInfo(*this).DiagAppertainsToDecl(S, *this, D);
193 }
194 
diagnoseLangOpts(Sema & S) const195 bool AttributeList::diagnoseLangOpts(Sema &S) const {
196   return getInfo(*this).DiagLangOpts(S, *this);
197 }
198 
isTargetSpecificAttr() const199 bool AttributeList::isTargetSpecificAttr() const {
200   return getInfo(*this).IsTargetSpecific;
201 }
202 
isTypeAttr() const203 bool AttributeList::isTypeAttr() const {
204   return getInfo(*this).IsType;
205 }
206 
existsInTarget(const TargetInfo & Target) const207 bool AttributeList::existsInTarget(const TargetInfo &Target) const {
208   return getInfo(*this).ExistsInTarget(Target);
209 }
210 
isKnownToGCC() const211 bool AttributeList::isKnownToGCC() const {
212   return getInfo(*this).IsKnownToGCC;
213 }
214 
getSemanticSpelling() const215 unsigned AttributeList::getSemanticSpelling() const {
216   return getInfo(*this).SpellingIndexToSemanticSpelling(*this);
217 }
218 
hasVariadicArg() const219 bool AttributeList::hasVariadicArg() const {
220   // If the attribute has the maximum number of optional arguments, we will
221   // claim that as being variadic. If we someday get an attribute that
222   // legitimately bumps up against that maximum, we can use another bit to track
223   // whether it's truly variadic or not.
224   return getInfo(*this).OptArgs == 15;
225 }
226