1//===--- Attr.h - Classes for representing attributes ----------*- 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// This file defines the Attr interface and subclasses.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CLANG_AST_ATTR_H
14#define LLVM_CLANG_AST_ATTR_H
15
16#include "clang/AST/ASTFwd.h"
17#include "clang/AST/AttrIterator.h"
18#include "clang/AST/Decl.h"
19#include "clang/AST/Type.h"
20#include "clang/Basic/AttrKinds.h"
21#include "clang/Basic/AttributeCommonInfo.h"
22#include "clang/Basic/LLVM.h"
23#include "clang/Basic/LangOptions.h"
24#include "clang/Basic/OpenMPKinds.h"
25#include "clang/Basic/Sanitizers.h"
26#include "clang/Basic/SourceLocation.h"
27#include "llvm/Frontend/HLSL/HLSLResource.h"
28#include "llvm/Support/CodeGen.h"
29#include "llvm/Support/ErrorHandling.h"
30#include "llvm/Support/VersionTuple.h"
31#include "llvm/Support/raw_ostream.h"
32#include <algorithm>
33#include <cassert>
34
35namespace clang {
36class ASTContext;
37class AttributeCommonInfo;
38class FunctionDecl;
39class OMPTraitInfo;
40
41/// Attr - This represents one attribute.
42class Attr : public AttributeCommonInfo {
43private:
44 LLVM_PREFERRED_TYPE(attr::Kind)
45 unsigned AttrKind : 16;
46
47protected:
48 /// An index into the spelling list of an
49 /// attribute defined in Attr.td file.
50 LLVM_PREFERRED_TYPE(bool)
51 unsigned Inherited : 1;
52 LLVM_PREFERRED_TYPE(bool)
53 unsigned IsPackExpansion : 1;
54 LLVM_PREFERRED_TYPE(bool)
55 unsigned Implicit : 1;
56 // FIXME: These are properties of the attribute kind, not state for this
57 // instance of the attribute.
58 LLVM_PREFERRED_TYPE(bool)
59 unsigned IsLateParsed : 1;
60 LLVM_PREFERRED_TYPE(bool)
61 unsigned InheritEvenIfAlreadyPresent : 1;
62
63 void *operator new(size_t bytes) noexcept {
64 llvm_unreachable("Attrs cannot be allocated with regular 'new'.");
65 }
66 void operator delete(void *data) noexcept {
67 llvm_unreachable("Attrs cannot be released with regular 'delete'.");
68 }
69
70public:
71 // Forward so that the regular new and delete do not hide global ones.
72 void *operator new(size_t Bytes, ASTContext &C,
73 size_t Alignment = 8) noexcept {
74 return ::operator new(Bytes, C, Alignment);
75 }
76 void operator delete(void *Ptr, ASTContext &C, size_t Alignment) noexcept {
77 return ::operator delete(Ptr, C, Alignment);
78 }
79
80protected:
81 Attr(ASTContext &Context, const AttributeCommonInfo &CommonInfo,
82 attr::Kind AK, bool IsLateParsed)
83 : AttributeCommonInfo(CommonInfo), AttrKind(AK), Inherited(false),
84 IsPackExpansion(false), Implicit(false), IsLateParsed(IsLateParsed),
85 InheritEvenIfAlreadyPresent(false) {}
86
87public:
88 attr::Kind getKind() const { return static_cast<attr::Kind>(AttrKind); }
89
90 unsigned getSpellingListIndex() const {
91 return getAttributeSpellingListIndex();
92 }
93 const char *getSpelling() const;
94
95 SourceLocation getLocation() const { return getRange().getBegin(); }
96
97 bool isInherited() const { return Inherited; }
98
99 /// Returns true if the attribute has been implicitly created instead
100 /// of explicitly written by the user.
101 bool isImplicit() const { return Implicit; }
102 void setImplicit(bool I) { Implicit = I; }
103
104 void setPackExpansion(bool PE) { IsPackExpansion = PE; }
105 bool isPackExpansion() const { return IsPackExpansion; }
106
107 // Clone this attribute.
108 Attr *clone(ASTContext &C) const;
109
110 bool isLateParsed() const { return IsLateParsed; }
111
112 // Pretty print this attribute.
113 void printPretty(raw_ostream &OS, const PrintingPolicy &Policy) const;
114
115 static StringRef getDocumentation(attr::Kind);
116};
117
118class TypeAttr : public Attr {
119protected:
120 TypeAttr(ASTContext &Context, const AttributeCommonInfo &CommonInfo,
121 attr::Kind AK, bool IsLateParsed)
122 : Attr(Context, CommonInfo, AK, IsLateParsed) {}
123
124public:
125 static bool classof(const Attr *A) {
126 return A->getKind() >= attr::FirstTypeAttr &&
127 A->getKind() <= attr::LastTypeAttr;
128 }
129};
130
131class StmtAttr : public Attr {
132protected:
133 StmtAttr(ASTContext &Context, const AttributeCommonInfo &CommonInfo,
134 attr::Kind AK, bool IsLateParsed)
135 : Attr(Context, CommonInfo, AK, IsLateParsed) {}
136
137public:
138 static bool classof(const Attr *A) {
139 return A->getKind() >= attr::FirstStmtAttr &&
140 A->getKind() <= attr::LastStmtAttr;
141 }
142};
143
144class InheritableAttr : public Attr {
145protected:
146 InheritableAttr(ASTContext &Context, const AttributeCommonInfo &CommonInfo,
147 attr::Kind AK, bool IsLateParsed,
148 bool InheritEvenIfAlreadyPresent)
149 : Attr(Context, CommonInfo, AK, IsLateParsed) {
150 this->InheritEvenIfAlreadyPresent = InheritEvenIfAlreadyPresent;
151 }
152
153public:
154 void setInherited(bool I) { Inherited = I; }
155
156 /// Should this attribute be inherited from a prior declaration even if it's
157 /// explicitly provided in the current declaration?
158 bool shouldInheritEvenIfAlreadyPresent() const {
159 return InheritEvenIfAlreadyPresent;
160 }
161
162 // Implement isa/cast/dyncast/etc.
163 static bool classof(const Attr *A) {
164 return A->getKind() >= attr::FirstInheritableAttr &&
165 A->getKind() <= attr::LastInheritableAttr;
166 }
167};
168
169class DeclOrStmtAttr : public InheritableAttr {
170protected:
171 DeclOrStmtAttr(ASTContext &Context, const AttributeCommonInfo &CommonInfo,
172 attr::Kind AK, bool IsLateParsed,
173 bool InheritEvenIfAlreadyPresent)
174 : InheritableAttr(Context, CommonInfo, AK, IsLateParsed,
175 InheritEvenIfAlreadyPresent) {}
176
177public:
178 static bool classof(const Attr *A) {
179 return A->getKind() >= attr::FirstDeclOrStmtAttr &&
180 A->getKind() <= attr::LastDeclOrStmtAttr;
181 }
182};
183
184class InheritableParamAttr : public InheritableAttr {
185protected:
186 InheritableParamAttr(ASTContext &Context,
187 const AttributeCommonInfo &CommonInfo, attr::Kind AK,
188 bool IsLateParsed, bool InheritEvenIfAlreadyPresent)
189 : InheritableAttr(Context, CommonInfo, AK, IsLateParsed,
190 InheritEvenIfAlreadyPresent) {}
191
192public:
193 // Implement isa/cast/dyncast/etc.
194 static bool classof(const Attr *A) {
195 return A->getKind() >= attr::FirstInheritableParamAttr &&
196 A->getKind() <= attr::LastInheritableParamAttr;
197 }
198};
199
200class HLSLAnnotationAttr : public InheritableAttr {
201protected:
202 HLSLAnnotationAttr(ASTContext &Context, const AttributeCommonInfo &CommonInfo,
203 attr::Kind AK, bool IsLateParsed,
204 bool InheritEvenIfAlreadyPresent)
205 : InheritableAttr(Context, CommonInfo, AK, IsLateParsed,
206 InheritEvenIfAlreadyPresent) {}
207
208public:
209 // Implement isa/cast/dyncast/etc.
210 static bool classof(const Attr *A) {
211 return A->getKind() >= attr::FirstHLSLAnnotationAttr &&
212 A->getKind() <= attr::LastHLSLAnnotationAttr;
213 }
214};
215
216/// A parameter attribute which changes the argument-passing ABI rule
217/// for the parameter.
218class ParameterABIAttr : public InheritableParamAttr {
219protected:
220 ParameterABIAttr(ASTContext &Context, const AttributeCommonInfo &CommonInfo,
221 attr::Kind AK, bool IsLateParsed,
222 bool InheritEvenIfAlreadyPresent)
223 : InheritableParamAttr(Context, CommonInfo, AK, IsLateParsed,
224 InheritEvenIfAlreadyPresent) {}
225
226public:
227 ParameterABI getABI() const {
228 switch (getKind()) {
229 case attr::SwiftContext:
230 return ParameterABI::SwiftContext;
231 case attr::SwiftAsyncContext:
232 return ParameterABI::SwiftAsyncContext;
233 case attr::SwiftErrorResult:
234 return ParameterABI::SwiftErrorResult;
235 case attr::SwiftIndirectResult:
236 return ParameterABI::SwiftIndirectResult;
237 default:
238 llvm_unreachable("bad parameter ABI attribute kind");
239 }
240 }
241
242 static bool classof(const Attr *A) {
243 return A->getKind() >= attr::FirstParameterABIAttr &&
244 A->getKind() <= attr::LastParameterABIAttr;
245 }
246};
247
248/// A single parameter index whose accessors require each use to make explicit
249/// the parameter index encoding needed.
250class ParamIdx {
251 // Idx is exposed only via accessors that specify specific encodings.
252 unsigned Idx : 30;
253 LLVM_PREFERRED_TYPE(bool)
254 unsigned HasThis : 1;
255 LLVM_PREFERRED_TYPE(bool)
256 unsigned IsValid : 1;
257
258 void assertComparable(const ParamIdx &I) const {
259 assert(isValid() && I.isValid() &&
260 "ParamIdx must be valid to be compared");
261 // It's possible to compare indices from separate functions, but so far
262 // it's not proven useful. Moreover, it might be confusing because a
263 // comparison on the results of getASTIndex might be inconsistent with a
264 // comparison on the ParamIdx objects themselves.
265 assert(HasThis == I.HasThis &&
266 "ParamIdx must be for the same function to be compared");
267 }
268
269public:
270 /// Construct an invalid parameter index (\c isValid returns false and
271 /// accessors fail an assert).
272 ParamIdx() : Idx(0), HasThis(false), IsValid(false) {}
273
274 /// \param Idx is the parameter index as it is normally specified in
275 /// attributes in the source: one-origin including any C++ implicit this
276 /// parameter.
277 ///
278 /// \param D is the declaration containing the parameters. It is used to
279 /// determine if there is a C++ implicit this parameter.
280 ParamIdx(unsigned Idx, const Decl *D)
281 : Idx(Idx), HasThis(false), IsValid(true) {
282 assert(Idx >= 1 && "Idx must be one-origin");
283 if (const auto *FD = dyn_cast<FunctionDecl>(Val: D))
284 HasThis = FD->isCXXInstanceMember();
285 }
286
287 /// A type into which \c ParamIdx can be serialized.
288 ///
289 /// A static assertion that it's of the correct size follows the \c ParamIdx
290 /// class definition.
291 typedef uint32_t SerialType;
292
293 /// Produce a representation that can later be passed to \c deserialize to
294 /// construct an equivalent \c ParamIdx.
295 SerialType serialize() const {
296 return *reinterpret_cast<const SerialType *>(this);
297 }
298
299 /// Construct from a result from \c serialize.
300 static ParamIdx deserialize(SerialType S) {
301 // Using this two-step static_cast via void * instead of reinterpret_cast
302 // silences a -Wstrict-aliasing false positive from GCC7 and earlier.
303 void *ParamIdxPtr = static_cast<void *>(&S);
304 ParamIdx P(*static_cast<ParamIdx *>(ParamIdxPtr));
305 assert((!P.IsValid || P.Idx >= 1) && "valid Idx must be one-origin");
306 return P;
307 }
308
309 /// Is this parameter index valid?
310 bool isValid() const { return IsValid; }
311
312 /// Get the parameter index as it would normally be encoded for attributes at
313 /// the source level of representation: one-origin including any C++ implicit
314 /// this parameter.
315 ///
316 /// This encoding thus makes sense for diagnostics, pretty printing, and
317 /// constructing new attributes from a source-like specification.
318 unsigned getSourceIndex() const {
319 assert(isValid() && "ParamIdx must be valid");
320 return Idx;
321 }
322
323 /// Get the parameter index as it would normally be encoded at the AST level
324 /// of representation: zero-origin not including any C++ implicit this
325 /// parameter.
326 ///
327 /// This is the encoding primarily used in Sema. However, in diagnostics,
328 /// Sema uses \c getSourceIndex instead.
329 unsigned getASTIndex() const {
330 assert(isValid() && "ParamIdx must be valid");
331 assert(Idx >= 1 + HasThis &&
332 "stored index must be base-1 and not specify C++ implicit this");
333 return Idx - 1 - HasThis;
334 }
335
336 /// Get the parameter index as it would normally be encoded at the LLVM level
337 /// of representation: zero-origin including any C++ implicit this parameter.
338 ///
339 /// This is the encoding primarily used in CodeGen.
340 unsigned getLLVMIndex() const {
341 assert(isValid() && "ParamIdx must be valid");
342 assert(Idx >= 1 && "stored index must be base-1");
343 return Idx - 1;
344 }
345
346 bool operator==(const ParamIdx &I) const {
347 assertComparable(I);
348 return Idx == I.Idx;
349 }
350 bool operator!=(const ParamIdx &I) const {
351 assertComparable(I);
352 return Idx != I.Idx;
353 }
354 bool operator<(const ParamIdx &I) const {
355 assertComparable(I);
356 return Idx < I.Idx;
357 }
358 bool operator>(const ParamIdx &I) const {
359 assertComparable(I);
360 return Idx > I.Idx;
361 }
362 bool operator<=(const ParamIdx &I) const {
363 assertComparable(I);
364 return Idx <= I.Idx;
365 }
366 bool operator>=(const ParamIdx &I) const {
367 assertComparable(I);
368 return Idx >= I.Idx;
369 }
370};
371
372static_assert(sizeof(ParamIdx) == sizeof(ParamIdx::SerialType),
373 "ParamIdx does not fit its serialization type");
374
375#include "clang/AST/Attrs.inc"
376
377inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
378 const Attr *At) {
379 DB.AddTaggedVal(V: reinterpret_cast<uint64_t>(At), Kind: DiagnosticsEngine::ak_attr);
380 return DB;
381}
382} // end namespace clang
383
384#endif
385

source code of clang/include/clang/AST/Attr.h