1 //===--- Attr.h - Classes for representing expressions ----------*- 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 Attr interface and subclasses.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #ifndef LLVM_CLANG_AST_ATTR_H
15 #define LLVM_CLANG_AST_ATTR_H
16
17 #include "clang/Basic/LLVM.h"
18 #include "clang/Basic/AttrKinds.h"
19 #include "clang/AST/Type.h"
20 #include "clang/Basic/SourceLocation.h"
21 #include "clang/Basic/VersionTuple.h"
22 #include "llvm/ADT/SmallVector.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/ADT/StringSwitch.h"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <cassert>
28 #include <cstring>
29 #include <algorithm>
30
31 namespace clang {
32 class ASTContext;
33 class IdentifierInfo;
34 class ObjCInterfaceDecl;
35 class Expr;
36 class QualType;
37 class FunctionDecl;
38 class TypeSourceInfo;
39 }
40
41 // Defined in ASTContext.h
42 void *operator new(size_t Bytes, const clang::ASTContext &C,
43 size_t Alignment = 16);
44 // FIXME: Being forced to not have a default argument here due to redeclaration
45 // rules on default arguments sucks
46 void *operator new[](size_t Bytes, const clang::ASTContext &C,
47 size_t Alignment);
48
49 // It is good practice to pair new/delete operators. Also, MSVC gives many
50 // warnings if a matching delete overload is not declared, even though the
51 // throw() spec guarantees it will not be implicitly called.
52 void operator delete(void *Ptr, const clang::ASTContext &C, size_t);
53 void operator delete[](void *Ptr, const clang::ASTContext &C, size_t);
54
55 namespace clang {
56
57 /// Attr - This represents one attribute.
58 class Attr {
59 private:
60 SourceRange Range;
61 unsigned AttrKind : 16;
62
63 protected:
64 bool Inherited : 1;
65
66 virtual ~Attr();
67
new(size_t bytes)68 void* operator new(size_t bytes) throw() {
69 llvm_unreachable("Attrs cannot be allocated with regular 'new'.");
70 }
delete(void * data)71 void operator delete(void* data) throw() {
72 llvm_unreachable("Attrs cannot be released with regular 'delete'.");
73 }
74
75 public:
76 // Forward so that the regular new and delete do not hide global ones.
77 void* operator new(size_t Bytes, ASTContext &C,
throw()78 size_t Alignment = 16) throw() {
79 return ::operator new(Bytes, C, Alignment);
80 }
delete(void * Ptr,ASTContext & C,size_t Alignment)81 void operator delete(void *Ptr, ASTContext &C,
82 size_t Alignment) throw() {
83 return ::operator delete(Ptr, C, Alignment);
84 }
85
86 protected:
Attr(attr::Kind AK,SourceRange R)87 Attr(attr::Kind AK, SourceRange R)
88 : Range(R), AttrKind(AK), Inherited(false) {}
89
90 public:
91
getKind()92 attr::Kind getKind() const {
93 return static_cast<attr::Kind>(AttrKind);
94 }
95
getLocation()96 SourceLocation getLocation() const { return Range.getBegin(); }
getRange()97 SourceRange getRange() const { return Range; }
setRange(SourceRange R)98 void setRange(SourceRange R) { Range = R; }
99
isInherited()100 bool isInherited() const { return Inherited; }
101
102 // Clone this attribute.
103 virtual Attr* clone(ASTContext &C) const = 0;
104
isLateParsed()105 virtual bool isLateParsed() const { return false; }
106
107 // Pretty print this attribute.
108 virtual void printPretty(llvm::raw_ostream &OS, ASTContext &C) const = 0;
109
110 // Implement isa/cast/dyncast/etc.
classof(const Attr *)111 static bool classof(const Attr *) { return true; }
112 };
113
114 class InheritableAttr : public Attr {
115 virtual void anchor();
116 protected:
InheritableAttr(attr::Kind AK,SourceRange R)117 InheritableAttr(attr::Kind AK, SourceRange R)
118 : Attr(AK, R) {}
119
120 public:
setInherited(bool I)121 void setInherited(bool I) { Inherited = I; }
122
123 // Implement isa/cast/dyncast/etc.
classof(const Attr * A)124 static bool classof(const Attr *A) {
125 return A->getKind() <= attr::LAST_INHERITABLE;
126 }
classof(const InheritableAttr *)127 static bool classof(const InheritableAttr *) { return true; }
128 };
129
130 class InheritableParamAttr : public InheritableAttr {
131 virtual void anchor();
132 protected:
InheritableParamAttr(attr::Kind AK,SourceRange R)133 InheritableParamAttr(attr::Kind AK, SourceRange R)
134 : InheritableAttr(AK, R) {}
135
136 public:
137 // Implement isa/cast/dyncast/etc.
classof(const Attr * A)138 static bool classof(const Attr *A) {
139 return A->getKind() <= attr::LAST_INHERITABLE_PARAM;
140 }
classof(const InheritableParamAttr *)141 static bool classof(const InheritableParamAttr *) { return true; }
142 };
143
144 #include "clang/AST/Attrs.inc"
145
146 /// AttrVec - A vector of Attr, which is how they are stored on the AST.
147 typedef SmallVector<Attr*, 2> AttrVec;
148 typedef SmallVector<const Attr*, 2> ConstAttrVec;
149
150 /// DestroyAttrs - Destroy the contents of an AttrVec.
DestroyAttrs(AttrVec & V,ASTContext & C)151 inline void DestroyAttrs (AttrVec& V, ASTContext &C) {
152 }
153
154 /// specific_attr_iterator - Iterates over a subrange of an AttrVec, only
155 /// providing attributes that are of a specifc type.
156 template <typename SpecificAttr>
157 class specific_attr_iterator {
158 /// Current - The current, underlying iterator.
159 /// In order to ensure we don't dereference an invalid iterator unless
160 /// specifically requested, we don't necessarily advance this all the
161 /// way. Instead, we advance it when an operation is requested; if the
162 /// operation is acting on what should be a past-the-end iterator,
163 /// then we offer no guarantees, but this way we do not dererence a
164 /// past-the-end iterator when we move to a past-the-end position.
165 mutable AttrVec::const_iterator Current;
166
AdvanceToNext()167 void AdvanceToNext() const {
168 while (!isa<SpecificAttr>(*Current))
169 ++Current;
170 }
171
AdvanceToNext(AttrVec::const_iterator I)172 void AdvanceToNext(AttrVec::const_iterator I) const {
173 while (Current != I && !isa<SpecificAttr>(*Current))
174 ++Current;
175 }
176
177 public:
178 typedef SpecificAttr* value_type;
179 typedef SpecificAttr* reference;
180 typedef SpecificAttr* pointer;
181 typedef std::forward_iterator_tag iterator_category;
182 typedef std::ptrdiff_t difference_type;
183
specific_attr_iterator()184 specific_attr_iterator() : Current() { }
specific_attr_iterator(AttrVec::const_iterator i)185 explicit specific_attr_iterator(AttrVec::const_iterator i) : Current(i) { }
186
187 reference operator*() const {
188 AdvanceToNext();
189 return cast<SpecificAttr>(*Current);
190 }
191 pointer operator->() const {
192 AdvanceToNext();
193 return cast<SpecificAttr>(*Current);
194 }
195
196 specific_attr_iterator& operator++() {
197 ++Current;
198 return *this;
199 }
200 specific_attr_iterator operator++(int) {
201 specific_attr_iterator Tmp(*this);
202 ++(*this);
203 return Tmp;
204 }
205
206 friend bool operator==(specific_attr_iterator Left,
207 specific_attr_iterator Right) {
208 if (Left.Current < Right.Current)
209 Left.AdvanceToNext(Right.Current);
210 else
211 Right.AdvanceToNext(Left.Current);
212 return Left.Current == Right.Current;
213 }
214 friend bool operator!=(specific_attr_iterator Left,
215 specific_attr_iterator Right) {
216 return !(Left == Right);
217 }
218 };
219
220 template <typename T>
specific_attr_begin(const AttrVec & vec)221 inline specific_attr_iterator<T> specific_attr_begin(const AttrVec& vec) {
222 return specific_attr_iterator<T>(vec.begin());
223 }
224 template <typename T>
specific_attr_end(const AttrVec & vec)225 inline specific_attr_iterator<T> specific_attr_end(const AttrVec& vec) {
226 return specific_attr_iterator<T>(vec.end());
227 }
228
229 template <typename T>
hasSpecificAttr(const AttrVec & vec)230 inline bool hasSpecificAttr(const AttrVec& vec) {
231 return specific_attr_begin<T>(vec) != specific_attr_end<T>(vec);
232 }
233 template <typename T>
getSpecificAttr(const AttrVec & vec)234 inline T *getSpecificAttr(const AttrVec& vec) {
235 specific_attr_iterator<T> i = specific_attr_begin<T>(vec);
236 if (i != specific_attr_end<T>(vec))
237 return *i;
238 else
239 return 0;
240 }
241
242 /// getMaxAlignment - Returns the highest alignment value found among
243 /// AlignedAttrs in an AttrVec, or 0 if there are none.
getMaxAttrAlignment(const AttrVec & V,ASTContext & Ctx)244 inline unsigned getMaxAttrAlignment(const AttrVec& V, ASTContext &Ctx) {
245 unsigned Align = 0;
246 specific_attr_iterator<AlignedAttr> i(V.begin()), e(V.end());
247 for(; i != e; ++i)
248 Align = std::max(Align, i->getAlignment(Ctx));
249 return Align;
250 }
251
252 } // end namespace clang
253
254 #endif
255