clang 8.0.0

CodeGenTBAA.cpp
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1 //===--- CodeGenTypes.cpp - TBAA information for LLVM CodeGen -------------===//
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 is the code that manages TBAA information and defines the TBAA policy
11 // for the optimizer to use. Relevant standards text includes:
12 //
13 // C99 6.5p7
14 // C++ [basic.lval] (p10 in n3126, p15 in some earlier versions)
15 //
16 //===----------------------------------------------------------------------===//
17
18 #include "CodeGenTBAA.h"
19 #include "clang/AST/ASTContext.h"
20 #include "clang/AST/Attr.h"
21 #include "clang/AST/Mangle.h"
22 #include "clang/AST/RecordLayout.h"
23 #include "clang/Basic/CodeGenOptions.h"
24 #include "llvm/ADT/SmallSet.h"
25 #include "llvm/IR/Constants.h"
26 #include "llvm/IR/LLVMContext.h"
27 #include "llvm/IR/Metadata.h"
28 #include "llvm/IR/Module.h"
29 #include "llvm/IR/Type.h"
30 using namespace clang;
31 using namespace CodeGen;
32
33 CodeGenTBAA::CodeGenTBAA(ASTContext &Ctx, llvm::Module &M,
34 const CodeGenOptions &CGO,
35 const LangOptions &Features, MangleContext &MContext)
36 : Context(Ctx), Module(M), CodeGenOpts(CGO),
37 Features(Features), MContext(MContext), MDHelper(M.getContext()),
38 Root(nullptr), Char(nullptr)
39 {}
40
41 CodeGenTBAA::~CodeGenTBAA() {
42 }
43
44 llvm::MDNode *CodeGenTBAA::getRoot() {
45 // Define the root of the tree. This identifies the tree, so that
46 // if our LLVM IR is linked with LLVM IR from a different front-end
47 // (or a different version of this front-end), their TBAA trees will
48 // remain distinct, and the optimizer will treat them conservatively.
49 if (!Root) {
50 if (Features.CPlusPlus)
51 Root = MDHelper.createTBAARoot("Simple C++ TBAA");
52 else
53 Root = MDHelper.createTBAARoot("Simple C/C++ TBAA");
54 }
55
56 return Root;
57 }
58
59 llvm::MDNode *CodeGenTBAA::createScalarTypeNode(StringRef Name,
60 llvm::MDNode *Parent,
61 uint64_t Size) {
62 if (CodeGenOpts.NewStructPathTBAA) {
63 llvm::Metadata *Id = MDHelper.createString(Name);
64 return MDHelper.createTBAATypeNode(Parent, Size, Id);
65 }
66 return MDHelper.createTBAAScalarTypeNode(Name, Parent);
67 }
68
69 llvm::MDNode *CodeGenTBAA::getChar() {
70 // Define the root of the tree for user-accessible memory. C and C++
71 // give special powers to char and certain similar types. However,
72 // these special powers only cover user-accessible memory, and doesn't
73 // include things like vtables.
74 if (!Char)
75 Char = createScalarTypeNode("omnipotent char", getRoot(), /* Size= */ 1);
76
77 return Char;
78 }
79
80 static bool TypeHasMayAlias(QualType QTy) {
81 // Tagged types have declarations, and therefore may have attributes.
82 if (const TagType *TTy = dyn_cast<TagType>(QTy))
83 return TTy->getDecl()->hasAttr<MayAliasAttr>();
84
85 // Typedef types have declarations, and therefore may have attributes.
86 if (const TypedefType *TTy = dyn_cast<TypedefType>(QTy)) {
87 if (TTy->getDecl()->hasAttr<MayAliasAttr>())
88 return true;
89 // Also, their underlying types may have relevant attributes.
90 return TypeHasMayAlias(TTy->desugar());
91 }
92
93 return false;
94 }
95
96 /// Check if the given type is a valid base type to be used in access tags.
97 static bool isValidBaseType(QualType QTy) {
98 if (QTy->isReferenceType())
99 return false;
100 if (const RecordType *TTy = QTy->getAs<RecordType>()) {
101 const RecordDecl *RD = TTy->getDecl()->getDefinition();
102 // Incomplete types are not valid base access types.
103 if (!RD)
104 return false;
105 if (RD->hasFlexibleArrayMember())
106 return false;
107 // RD can be struct, union, class, interface or enum.
108 // For now, we only handle struct and class.
109 if (RD->isStruct() || RD->isClass())
110 return true;
111 }
112 return false;
113 }
114
115 llvm::MDNode *CodeGenTBAA::getTypeInfoHelper(const Type *Ty) {
116 uint64_t Size = Context.getTypeSizeInChars(Ty).getQuantity();
117
118 // Handle builtin types.
119 if (const BuiltinType *BTy = dyn_cast<BuiltinType>(Ty)) {
120 switch (BTy->getKind()) {
121 // Character types are special and can alias anything.
122 // In C++, this technically only includes "char" and "unsigned char",
123 // and not "signed char". In C, it includes all three. For now,
124 // the risk of exploiting this detail in C++ seems likely to outweigh
125 // the benefit.
126 case BuiltinType::Char_U:
127 case BuiltinType::Char_S:
128 case BuiltinType::UChar:
129 case BuiltinType::SChar:
130 return getChar();
131
132 // Unsigned types can alias their corresponding signed types.
133 case BuiltinType::UShort:
134 return getTypeInfo(Context.ShortTy);
135 case BuiltinType::UInt:
136 return getTypeInfo(Context.IntTy);
137 case BuiltinType::ULong:
138 return getTypeInfo(Context.LongTy);
139 case BuiltinType::ULongLong:
140 return getTypeInfo(Context.LongLongTy);
141 case BuiltinType::UInt128:
142 return getTypeInfo(Context.Int128Ty);
143
144 // Treat all other builtin types as distinct types. This includes
145 // treating wchar_t, char16_t, and char32_t as distinct from their
146 // "underlying types".
147 default:
148 return createScalarTypeNode(BTy->getName(Features), getChar(), Size);
149 }
150 }
151
152 // C++1z [basic.lval]p10: "If a program attempts to access the stored value of
153 // an object through a glvalue of other than one of the following types the
154 // behavior is undefined: [...] a char, unsigned char, or std::byte type."
155 if (Ty->isStdByteType())
156 return getChar();
157
158 // Handle pointers and references.
159 // TODO: Implement C++'s type "similarity" and consider dis-"similar"
160 // pointers distinct.
161 if (Ty->isPointerType() || Ty->isReferenceType())
162 return createScalarTypeNode("any pointer", getChar(), Size);
163
164 // Accesses to arrays are accesses to objects of their element types.
165 if (CodeGenOpts.NewStructPathTBAA && Ty->isArrayType())
166 return getTypeInfo(cast<ArrayType>(Ty)->getElementType());
167
168 // Enum types are distinct types. In C++ they have "underlying types",
169 // however they aren't related for TBAA.
170 if (const EnumType *ETy = dyn_cast<EnumType>(Ty)) {
171 // In C++ mode, types have linkage, so we can rely on the ODR and
172 // on their mangled names, if they're external.
173 // TODO: Is there a way to get a program-wide unique name for a
174 // decl with local linkage or no linkage?
175 if (!Features.CPlusPlus || !ETy->getDecl()->isExternallyVisible())
176 return getChar();
177
178 SmallString<256> OutName;
179 llvm::raw_svector_ostream Out(OutName);
180 MContext.mangleTypeName(QualType(ETy, 0), Out);
181 return createScalarTypeNode(OutName, getChar(), Size);
182 }
183
184 // For now, handle any other kind of type conservatively.
185 return getChar();
186 }
187
188 llvm::MDNode *CodeGenTBAA::getTypeInfo(QualType QTy) {
189 // At -O0 or relaxed aliasing, TBAA is not emitted for regular types.
190 if (CodeGenOpts.OptimizationLevel == 0 || CodeGenOpts.RelaxedAliasing)
191 return nullptr;
192
193 // If the type has the may_alias attribute (even on a typedef), it is
194 // effectively in the general char alias class.
195 if (TypeHasMayAlias(QTy))
196 return getChar();
197
198 // We need this function to not fall back to returning the "omnipotent char"
199 // type node for aggregate and union types. Otherwise, any dereference of an
200 // aggregate will result into the may-alias access descriptor, meaning all
201 // subsequent accesses to direct and indirect members of that aggregate will
202 // be considered may-alias too.
203 // TODO: Combine getTypeInfo() and getBaseTypeInfo() into a single function.
204 if (isValidBaseType(QTy))
205 return getBaseTypeInfo(QTy);
206
207 const Type *Ty = Context.getCanonicalType(QTy).getTypePtr();
208 if (llvm::MDNode *N = MetadataCache[Ty])
209 return N;
210
211 // Note that the following helper call is allowed to add new nodes to the
212 // cache, which invalidates all its previously obtained iterators. So we
213 // first generate the node for the type and then add that node to the cache.
214 llvm::MDNode *TypeNode = getTypeInfoHelper(Ty);
215 return MetadataCache[Ty] = TypeNode;
216 }
217
218 TBAAAccessInfo CodeGenTBAA::getAccessInfo(QualType AccessType) {
219 // Pointee values may have incomplete types, but they shall never be
220 // dereferenced.
221 if (AccessType->isIncompleteType())
222 return TBAAAccessInfo::getIncompleteInfo();
223
224 if (TypeHasMayAlias(AccessType))
225 return TBAAAccessInfo::getMayAliasInfo();
226
227 uint64_t Size = Context.getTypeSizeInChars(AccessType).getQuantity();
228 return TBAAAccessInfo(getTypeInfo(AccessType), Size);
229 }
230
231 TBAAAccessInfo CodeGenTBAA::getVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
232 llvm::DataLayout DL(&Module);
233 unsigned Size = DL.getPointerTypeSize(VTablePtrType);
234 return TBAAAccessInfo(createScalarTypeNode("vtable pointer", getRoot(), Size),
235 Size);
236 }
237
238 bool
239 CodeGenTBAA::CollectFields(uint64_t BaseOffset,
240 QualType QTy,
241 SmallVectorImpl<llvm::MDBuilder::TBAAStructField> &
242 Fields,
243 bool MayAlias) {
244 /* Things not handled yet include: C++ base classes, bitfields, */
245
246 if (const RecordType *TTy = QTy->getAs<RecordType>()) {
247 const RecordDecl *RD = TTy->getDecl()->getDefinition();
248 if (RD->hasFlexibleArrayMember())
249 return false;
250
251 // TODO: Handle C++ base classes.
252 if (const CXXRecordDecl *Decl = dyn_cast<CXXRecordDecl>(RD))
253 if (Decl->bases_begin() != Decl->bases_end())
254 return false;
255
256 const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
257
258 unsigned idx = 0;
259 for (RecordDecl::field_iterator i = RD->field_begin(),
260 e = RD->field_end(); i != e; ++i, ++idx) {
261 uint64_t Offset = BaseOffset +
262 Layout.getFieldOffset(idx) / Context.getCharWidth();
263 QualType FieldQTy = i->getType();
264 if (!CollectFields(Offset, FieldQTy, Fields,
265 MayAlias || TypeHasMayAlias(FieldQTy)))
266 return false;
267 }
268 return true;
269 }
270
271 /* Otherwise, treat whatever it is as a field. */
272 uint64_t Offset = BaseOffset;
273 uint64_t Size = Context.getTypeSizeInChars(QTy).getQuantity();
274 llvm::MDNode *TBAAType = MayAlias ? getChar() : getTypeInfo(QTy);
275 llvm::MDNode *TBAATag = getAccessTagInfo(TBAAAccessInfo(TBAAType, Size));
276 Fields.push_back(llvm::MDBuilder::TBAAStructField(Offset, Size, TBAATag));
277 return true;
278 }
279
280 llvm::MDNode *
281 CodeGenTBAA::getTBAAStructInfo(QualType QTy) {
282 const Type *Ty = Context.getCanonicalType(QTy).getTypePtr();
283
284 if (llvm::MDNode *N = StructMetadataCache[Ty])
285 return N;
286
287 SmallVector<llvm::MDBuilder::TBAAStructField, 4> Fields;
288 if (CollectFields(0, QTy, Fields, TypeHasMayAlias(QTy)))
289 return MDHelper.createTBAAStructNode(Fields);
290
291 // For now, handle any other kind of type conservatively.
292 return StructMetadataCache[Ty] = nullptr;
293 }
294
295 llvm::MDNode *CodeGenTBAA::getBaseTypeInfoHelper(const Type *Ty) {
296 if (auto *TTy = dyn_cast<RecordType>(Ty)) {
297 const RecordDecl *RD = TTy->getDecl()->getDefinition();
298 const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
299 SmallVector<llvm::MDBuilder::TBAAStructField, 4> Fields;
300 for (FieldDecl *Field : RD->fields()) {
301 QualType FieldQTy = Field->getType();
302 llvm::MDNode *TypeNode = isValidBaseType(FieldQTy) ?
303 getBaseTypeInfo(FieldQTy) : getTypeInfo(FieldQTy);
304 if (!TypeNode)
305 return BaseTypeMetadataCache[Ty] = nullptr;
306
307 uint64_t BitOffset = Layout.getFieldOffset(Field->getFieldIndex());
308 uint64_t Offset = Context.toCharUnitsFromBits(BitOffset).getQuantity();
309 uint64_t Size = Context.getTypeSizeInChars(FieldQTy).getQuantity();
310 Fields.push_back(llvm::MDBuilder::TBAAStructField(Offset, Size,
311 TypeNode));
312 }
313
314 SmallString<256> OutName;
315 if (Features.CPlusPlus) {
316 // Don't use the mangler for C code.
317 llvm::raw_svector_ostream Out(OutName);
318 MContext.mangleTypeName(QualType(Ty, 0), Out);
319 } else {
320 OutName = RD->getName();
321 }
322
323 if (CodeGenOpts.NewStructPathTBAA) {
324 llvm::MDNode *Parent = getChar();
325 uint64_t Size = Context.getTypeSizeInChars(Ty).getQuantity();
326 llvm::Metadata *Id = MDHelper.createString(OutName);
327 return MDHelper.createTBAATypeNode(Parent, Size, Id, Fields);
328 }
329
330 // Create the struct type node with a vector of pairs (offset, type).
331 SmallVector<std::pair<llvm::MDNode*, uint64_t>, 4> OffsetsAndTypes;
332 for (const auto &Field : Fields)
333 OffsetsAndTypes.push_back(std::make_pair(Field.Type, Field.Offset));
334 return MDHelper.createTBAAStructTypeNode(OutName, OffsetsAndTypes);
335 }
336
337 return nullptr;
338 }
339
340 llvm::MDNode *CodeGenTBAA::getBaseTypeInfo(QualType QTy) {
341 if (!isValidBaseType(QTy))
342 return nullptr;
343
344 const Type *Ty = Context.getCanonicalType(QTy).getTypePtr();
345 if (llvm::MDNode *N = BaseTypeMetadataCache[Ty])
346 return N;
347
348 // Note that the following helper call is allowed to add new nodes to the
349 // cache, which invalidates all its previously obtained iterators. So we
350 // first generate the node for the type and then add that node to the cache.
351 llvm::MDNode *TypeNode = getBaseTypeInfoHelper(Ty);
352 return BaseTypeMetadataCache[Ty] = TypeNode;
353 }
354
355 llvm::MDNode *CodeGenTBAA::getAccessTagInfo(TBAAAccessInfo Info) {
356 assert(!Info.isIncomplete() && "Access to an object of an incomplete type!");
357
358 if (Info.isMayAlias())
359 Info = TBAAAccessInfo(getChar(), Info.Size);
360
361 if (!Info.AccessType)
362 return nullptr;
363
364 if (!CodeGenOpts.StructPathTBAA)
365 Info = TBAAAccessInfo(Info.AccessType, Info.Size);
366
367 llvm::MDNode *&N = AccessTagMetadataCache[Info];
368 if (N)
369 return N;
370
371 if (!Info.BaseType) {
372 Info.BaseType = Info.AccessType;
373 assert(!Info.Offset && "Nonzero offset for an access with no base type!");
374 }
375 if (CodeGenOpts.NewStructPathTBAA) {
376 return N = MDHelper.createTBAAAccessTag(Info.BaseType, Info.AccessType,
377 Info.Offset, Info.Size);
378 }
379 return N = MDHelper.createTBAAStructTagNode(Info.BaseType, Info.AccessType,
380 Info.Offset);
381 }
382
383 TBAAAccessInfo CodeGenTBAA::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
384 TBAAAccessInfo TargetInfo) {
385 if (SourceInfo.isMayAlias() || TargetInfo.isMayAlias())
386 return TBAAAccessInfo::getMayAliasInfo();
387 return TargetInfo;
388 }
389
390 TBAAAccessInfo
391 CodeGenTBAA::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
392 TBAAAccessInfo InfoB) {
393 if (InfoA == InfoB)
394 return InfoA;
395
396 if (!InfoA || !InfoB)
397 return TBAAAccessInfo();
398
399 if (InfoA.isMayAlias() || InfoB.isMayAlias())
400 return TBAAAccessInfo::getMayAliasInfo();
401
402 // TODO: Implement the rest of the logic here. For example, two accesses
403 // with same final access types result in an access to an object of that final
404 // access type regardless of their base types.
405 return TBAAAccessInfo::getMayAliasInfo();
406 }
407
408 TBAAAccessInfo
409 CodeGenTBAA::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
410 TBAAAccessInfo SrcInfo) {
411 if (DestInfo == SrcInfo)
412 return DestInfo;
413
414 if (!DestInfo || !SrcInfo)
415 return TBAAAccessInfo();
416
417 if (DestInfo.isMayAlias() || SrcInfo.isMayAlias())
418 return TBAAAccessInfo::getMayAliasInfo();
419
420 // TODO: Implement the rest of the logic here. For example, two accesses
421 // with same final access types result in an access to an object of that final
422 // access type regardless of their base types.
423 return TBAAAccessInfo::getMayAliasInfo();
424 }
ASTContext.h
Defines the clang::ASTContext interface.
clang::TagDecl::isStruct
bool isStruct() const
Definition: Decl.h:3249
clang::ASTContext::LongLongTy
CanQualType LongLongTy
Definition: ASTContext.h:1025
clang::QualType
A (possibly-)qualified type.
Definition: Type.h:638
clang::Type::isArrayType
bool isArrayType() const
Definition: Type.h:6345
clang::ASTContext::getASTRecordLayout
const ASTRecordLayout & getASTRecordLayout(const RecordDecl *D) const
Get or compute information about the layout of the specified record (struct/union/class) D...
Definition: RecordLayoutBuilder.cpp:2966
clang::Decl
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:87
clang::CodeGen::TBAAAccessInfo::AccessType
llvm::MDNode * AccessType
AccessType - The final access type.
Definition: CodeGenTBAA.h:106
clang::Type
The base class of the type hierarchy.
Definition: Type.h:1407
clang::ASTContext::LongTy
CanQualType LongTy
Definition: ASTContext.h:1025
clang::CodeGen::CodeGenTBAA::getAccessInfo
TBAAAccessInfo getAccessInfo(QualType AccessType)
getAccessInfo - Get TBAA information that describes an access to an object of the given type...
Definition: CodeGenTBAA.cpp:218
clang::CodeGen::CodeGenTBAA::CodeGenTBAA
CodeGenTBAA(ASTContext &Ctx, llvm::Module &M, const CodeGenOptions &CGO, const LangOptions &Features, MangleContext &MContext)
Definition: CodeGenTBAA.cpp:33
clang::Type::getAs
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6748
clang::CodeGen::TBAAAccessKind::MayAlias
clang::CodeGen::TBAAAccessInfo::isMayAlias
bool isMayAlias() const
Definition: CodeGenTBAA.h:70
clang::TagDecl::isClass
bool isClass() const
Definition: Decl.h:3251
clang::RecordDecl
Represents a struct/union/class.
Definition: Decl.h:3593
clang::ASTContext
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:155
clang::Type::isStdByteType
bool isStdByteType() const
Definition: Type.cpp:2446
clang::RecordDecl::getDefinition
RecordDecl * getDefinition() const
Returns the RecordDecl that actually defines this struct/union/class.
Definition: Decl.h:3774
clang::RecordDecl::fields
field_range fields() const
Definition: Decl.h:3784
clang::FieldDecl
Represents a member of a struct/union/class.
Definition: Decl.h:2579
clang::Type::isReferenceType
bool isReferenceType() const
Definition: Type.h:6308
clang::LangOptions
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:50
clang::Module
Describes a module or submodule.
Definition: Module.h:65
llvm::SmallVectorImpl
Definition: LLVM.h:37
clang::CodeGen::TBAAAccessInfo::isIncomplete
bool isIncomplete() const
Definition: CodeGenTBAA.h:78
isValidBaseType
static bool isValidBaseType(QualType QTy)
Check if the given type is a valid base type to be used in access tags.
Definition: CodeGenTBAA.cpp:97
clang::CodeGen::CodeGenTBAA::getVTablePtrAccessInfo
TBAAAccessInfo getVTablePtrAccessInfo(llvm::Type *VTablePtrType)
getVTablePtrAccessInfo - Get the TBAA information that describes an access to a virtual table pointer...
Definition: CodeGenTBAA.cpp:231
clang::RecordDecl::field_begin
field_iterator field_begin() const
Definition: Decl.cpp:4145
clang::CodeGen::TBAAAccessInfo::getIncompleteInfo
static TBAAAccessInfo getIncompleteInfo()
Definition: CodeGenTBAA.h:72
Mangle.h
llvm::SmallString
Definition: LLVM.h:35
clang::CanQual::getTypePtr
const T * getTypePtr() const
Retrieve the underlying type pointer, which refers to a canonical type.
Definition: CanonicalType.h:84
Parent
NodeId Parent
Definition: ASTDiff.cpp:192
clang::CharUnits::getQuantity
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
Offset
unsigned Offset
Definition: Format.cpp:1631
clang::ASTRecordLayout
ASTRecordLayout - This class contains layout information for one RecordDecl, which is a struct/union/...
Definition: RecordLayout.h:39
clang::TargetInfo
Exposes information about the current target.
Definition: TargetInfo.h:54
Id
int Id
Definition: ASTDiff.cpp:191
clang::CodeGen::CodeGenTBAA::mergeTBAAInfoForMemoryTransfer
TBAAAccessInfo mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo, TBAAAccessInfo SrcInfo)
mergeTBAAInfoForMemoryTransfer - Get merged TBAA information for the purpose of memory transfer calls...
Definition: CodeGenTBAA.cpp:409
TypeHasMayAlias
static bool TypeHasMayAlias(QualType QTy)
Definition: CodeGenTBAA.cpp:80
clang::RecordDecl::field_end
field_iterator field_end() const
Definition: Decl.h:3787
clang::ASTContext::ShortTy
CanQualType ShortTy
Definition: ASTContext.h:1025
clang::CodeGen::CodeGenTBAA::getBaseTypeInfo
llvm::MDNode * getBaseTypeInfo(QualType QTy)
getBaseTypeInfo - Get metadata that describes the given base access type.
Definition: CodeGenTBAA.cpp:340
clang::CodeGen::CodeGenTBAA::mergeTBAAInfoForCast
TBAAAccessInfo mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo, TBAAAccessInfo TargetInfo)
mergeTBAAInfoForCast - Get merged TBAA information for the purpose of type casts. ...
Definition: CodeGenTBAA.cpp:383
clang::CodeGen::AlignmentSource::Type
The l-value was considered opaque, so the alignment was determined from a type.
clang::ASTRecordLayout::getFieldOffset
uint64_t getFieldOffset(unsigned FieldNo) const
getFieldOffset - Get the offset of the given field index, in bits.
Definition: RecordLayout.h:191
Attr.h
clang::CodeGen::CodeGenTBAA::mergeTBAAInfoForConditionalOperator
TBAAAccessInfo mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA, TBAAAccessInfo InfoB)
mergeTBAAInfoForConditionalOperator - Get merged TBAA information for the purpose of conditional oper...
Definition: CodeGenTBAA.cpp:391
clang::EnumType
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of enums...
Definition: Type.h:4396
clang::ASTContext::Int128Ty
CanQualType Int128Ty
Definition: ASTContext.h:1025
clang::CodeGen::TBAAAccessInfo::BaseType
llvm::MDNode * BaseType
BaseType - The base/leading access type.
Definition: CodeGenTBAA.h:102
clang::CodeGen::CodeGenTBAA::~CodeGenTBAA
~CodeGenTBAA()
Definition: CodeGenTBAA.cpp:41
clang::MangleContext
MangleContext - Context for tracking state which persists across multiple calls to the C++ name mangl...
Definition: Mangle.h:44
llvm::SmallVector
Definition: LLVM.h:36
clang::CodeGen::TBAAAccessInfo::Size
uint64_t Size
Size - The size of access, in bytes.
Definition: CodeGenTBAA.h:113
clang::CodeGen::CodeGenTBAA::getTBAAStructInfo
llvm::MDNode * getTBAAStructInfo(QualType QTy)
getTBAAStructInfo - Get the TBAAStruct MDNode to be used for a memcpy of the given type...
Definition: CodeGenTBAA.cpp:281
clang::RecordDecl::hasFlexibleArrayMember
bool hasFlexibleArrayMember() const
Definition: Decl.h:3647
clang::MangleContext::mangleTypeName
virtual void mangleTypeName(QualType T, raw_ostream &)=0
Generates a unique string for an externally visible type for use with TBAA or type uniquing...
clang::CodeGen::CodeGenTBAA::getTypeInfo
llvm::MDNode * getTypeInfo(QualType QTy)
getTypeInfo - Get metadata used to describe accesses to objects of the given type.
Definition: CodeGenTBAA.cpp:188
clang
Dataflow Directional Tag Classes.
Definition: CFGReachabilityAnalysis.h:22
CodeGenOptions.h
clang::DeclContext::specific_decl_iterator
specific_decl_iterator - Iterates over a subrange of declarations stored in a DeclContext, providing only those that are of type SpecificDecl (or a class derived from it).
Definition: DeclBase.h:2017
clang::RecordType
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4370
clang::ASTContext::getCharWidth
uint64_t getCharWidth() const
Return the size of the character type, in bits.
Definition: ASTContext.h:2074
clang::CodeGenOptions
CodeGenOptions - Track various options which control how the code is optimized and passed to the back...
Definition: CodeGenOptions.h:46
clang::Type::isIncompleteType
bool isIncompleteType(NamedDecl **Def=nullptr) const
Types are partitioned into 3 broad categories (C99 6.2.5p1): object types, function types...
Definition: Type.cpp:2031
clang::ASTContext::getCanonicalType
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2253
clang::ASTContext::toCharUnitsFromBits
CharUnits toCharUnitsFromBits(int64_t BitSize) const
Convert a size in bits to a size in characters.
Definition: ASTContext.cpp:2156
clang::CXXRecordDecl
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
RecordLayout.h
clang::BuiltinType
This class is used for builtin types like &#39;int&#39;.
Definition: Type.h:2391
CodeGenTBAA.h
clang::CodeGen::CodeGenTBAA::getAccessTagInfo
llvm::MDNode * getAccessTagInfo(TBAAAccessInfo Info)
getAccessTagInfo - Get TBAA tag for a given memory access.
Definition: CodeGenTBAA.cpp:355
clang::NamedDecl::getName
StringRef getName() const
Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:276
clang::CodeGen::TBAAAccessInfo
Definition: CodeGenTBAA.h:43
clang::ASTContext::IntTy
CanQualType IntTy
Definition: ASTContext.h:1025
clang::Type::isPointerType
bool isPointerType() const
Definition: Type.h:6296
clang::TypedefType
Definition: Type.h:4151
clang::ASTContext::getTypeSizeInChars
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
Definition: ASTContext.cpp:2167
clang::CodeGen::TBAAAccessInfo::Offset
uint64_t Offset
Offset - The byte offset of the final access within the base one.
Definition: CodeGenTBAA.h:110
clang::TagType
Definition: Type.h:4347
clang::CodeGen::TBAAAccessInfo::getMayAliasInfo
static TBAAAccessInfo getMayAliasInfo()
Definition: CodeGenTBAA.h:64