clang 19.0.0git
CodeGenTBAA.cpp
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1//===-- CodeGenTBAA.cpp - TBAA information for LLVM CodeGen ---------------===//
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 is the code that manages TBAA information and defines the TBAA policy
10// for the optimizer to use. Relevant standards text includes:
11//
12// C99 6.5p7
13// C++ [basic.lval] (p10 in n3126, p15 in some earlier versions)
14//
15//===----------------------------------------------------------------------===//
16
17#include "CodeGenTBAA.h"
18#include "CGRecordLayout.h"
19#include "CodeGenTypes.h"
21#include "clang/AST/Attr.h"
22#include "clang/AST/Mangle.h"
26#include "llvm/ADT/SmallSet.h"
27#include "llvm/IR/Constants.h"
28#include "llvm/IR/LLVMContext.h"
29#include "llvm/IR/Metadata.h"
30#include "llvm/IR/Module.h"
31#include "llvm/IR/Type.h"
32#include "llvm/Support/Debug.h"
33using namespace clang;
34using namespace CodeGen;
35
37 llvm::Module &M, const CodeGenOptions &CGO,
38 const LangOptions &Features, MangleContext &MContext)
39 : Context(Ctx), CGTypes(CGTypes), Module(M), CodeGenOpts(CGO),
40 Features(Features), MContext(MContext), MDHelper(M.getContext()),
41 Root(nullptr), Char(nullptr) {}
42
44}
45
46llvm::MDNode *CodeGenTBAA::getRoot() {
47 // Define the root of the tree. This identifies the tree, so that
48 // if our LLVM IR is linked with LLVM IR from a different front-end
49 // (or a different version of this front-end), their TBAA trees will
50 // remain distinct, and the optimizer will treat them conservatively.
51 if (!Root) {
52 if (Features.CPlusPlus)
53 Root = MDHelper.createTBAARoot("Simple C++ TBAA");
54 else
55 Root = MDHelper.createTBAARoot("Simple C/C++ TBAA");
56 }
57
58 return Root;
59}
60
61llvm::MDNode *CodeGenTBAA::createScalarTypeNode(StringRef Name,
62 llvm::MDNode *Parent,
63 uint64_t Size) {
64 if (CodeGenOpts.NewStructPathTBAA) {
65 llvm::Metadata *Id = MDHelper.createString(Name);
66 return MDHelper.createTBAATypeNode(Parent, Size, Id);
67 }
68 return MDHelper.createTBAAScalarTypeNode(Name, Parent);
69}
70
71llvm::MDNode *CodeGenTBAA::getChar() {
72 // Define the root of the tree for user-accessible memory. C and C++
73 // give special powers to char and certain similar types. However,
74 // these special powers only cover user-accessible memory, and doesn't
75 // include things like vtables.
76 if (!Char)
77 Char = createScalarTypeNode("omnipotent char", getRoot(), /* Size= */ 1);
78
79 return Char;
80}
81
82static bool TypeHasMayAlias(QualType QTy) {
83 // Tagged types have declarations, and therefore may have attributes.
84 if (auto *TD = QTy->getAsTagDecl())
85 if (TD->hasAttr<MayAliasAttr>())
86 return true;
87
88 // Also look for may_alias as a declaration attribute on a typedef.
89 // FIXME: We should follow GCC and model may_alias as a type attribute
90 // rather than as a declaration attribute.
91 while (auto *TT = QTy->getAs<TypedefType>()) {
92 if (TT->getDecl()->hasAttr<MayAliasAttr>())
93 return true;
94 QTy = TT->desugar();
95 }
96 return false;
97}
98
99/// Check if the given type is a valid base type to be used in access tags.
100static bool isValidBaseType(QualType QTy) {
101 if (const RecordType *TTy = QTy->getAs<RecordType>()) {
102 const RecordDecl *RD = TTy->getDecl()->getDefinition();
103 // Incomplete types are not valid base access types.
104 if (!RD)
105 return false;
106 if (RD->hasFlexibleArrayMember())
107 return false;
108 // RD can be struct, union, class, interface or enum.
109 // For now, we only handle struct and class.
110 if (RD->isStruct() || RD->isClass())
111 return true;
112 }
113 return false;
114}
115
116llvm::MDNode *CodeGenTBAA::getTypeInfoHelper(const Type *Ty) {
118
119 // Handle builtin types.
120 if (const BuiltinType *BTy = dyn_cast<BuiltinType>(Ty)) {
121 switch (BTy->getKind()) {
122 // Character types are special and can alias anything.
123 // In C++, this technically only includes "char" and "unsigned char",
124 // and not "signed char". In C, it includes all three. For now,
125 // the risk of exploiting this detail in C++ seems likely to outweigh
126 // the benefit.
127 case BuiltinType::Char_U:
128 case BuiltinType::Char_S:
129 case BuiltinType::UChar:
130 case BuiltinType::SChar:
131 return getChar();
132
133 // Unsigned types can alias their corresponding signed types.
134 case BuiltinType::UShort:
135 return getTypeInfo(Context.ShortTy);
136 case BuiltinType::UInt:
137 return getTypeInfo(Context.IntTy);
138 case BuiltinType::ULong:
139 return getTypeInfo(Context.LongTy);
140 case BuiltinType::ULongLong:
141 return getTypeInfo(Context.LongLongTy);
142 case BuiltinType::UInt128:
143 return getTypeInfo(Context.Int128Ty);
144
145 case BuiltinType::UShortFract:
146 return getTypeInfo(Context.ShortFractTy);
147 case BuiltinType::UFract:
148 return getTypeInfo(Context.FractTy);
149 case BuiltinType::ULongFract:
150 return getTypeInfo(Context.LongFractTy);
151
152 case BuiltinType::SatUShortFract:
153 return getTypeInfo(Context.SatShortFractTy);
154 case BuiltinType::SatUFract:
155 return getTypeInfo(Context.SatFractTy);
156 case BuiltinType::SatULongFract:
157 return getTypeInfo(Context.SatLongFractTy);
158
159 case BuiltinType::UShortAccum:
160 return getTypeInfo(Context.ShortAccumTy);
161 case BuiltinType::UAccum:
162 return getTypeInfo(Context.AccumTy);
163 case BuiltinType::ULongAccum:
164 return getTypeInfo(Context.LongAccumTy);
165
166 case BuiltinType::SatUShortAccum:
167 return getTypeInfo(Context.SatShortAccumTy);
168 case BuiltinType::SatUAccum:
169 return getTypeInfo(Context.SatAccumTy);
170 case BuiltinType::SatULongAccum:
171 return getTypeInfo(Context.SatLongAccumTy);
172
173 // Treat all other builtin types as distinct types. This includes
174 // treating wchar_t, char16_t, and char32_t as distinct from their
175 // "underlying types".
176 default:
177 return createScalarTypeNode(BTy->getName(Features), getChar(), Size);
178 }
179 }
180
181 // C++1z [basic.lval]p10: "If a program attempts to access the stored value of
182 // an object through a glvalue of other than one of the following types the
183 // behavior is undefined: [...] a char, unsigned char, or std::byte type."
184 if (Ty->isStdByteType())
185 return getChar();
186
187 // Handle pointers and references.
188 // TODO: Implement C++'s type "similarity" and consider dis-"similar"
189 // pointers distinct.
190 if (Ty->isPointerType() || Ty->isReferenceType())
191 return createScalarTypeNode("any pointer", getChar(), Size);
192
193 // Accesses to arrays are accesses to objects of their element types.
194 if (CodeGenOpts.NewStructPathTBAA && Ty->isArrayType())
195 return getTypeInfo(cast<ArrayType>(Ty)->getElementType());
196
197 // Enum types are distinct types. In C++ they have "underlying types",
198 // however they aren't related for TBAA.
199 if (const EnumType *ETy = dyn_cast<EnumType>(Ty)) {
200 if (!Features.CPlusPlus)
201 return getTypeInfo(ETy->getDecl()->getIntegerType());
202
203 // In C++ mode, types have linkage, so we can rely on the ODR and
204 // on their mangled names, if they're external.
205 // TODO: Is there a way to get a program-wide unique name for a
206 // decl with local linkage or no linkage?
207 if (!ETy->getDecl()->isExternallyVisible())
208 return getChar();
209
210 SmallString<256> OutName;
211 llvm::raw_svector_ostream Out(OutName);
212 MContext.mangleCanonicalTypeName(QualType(ETy, 0), Out);
213 return createScalarTypeNode(OutName, getChar(), Size);
214 }
215
216 if (const auto *EIT = dyn_cast<BitIntType>(Ty)) {
217 SmallString<256> OutName;
218 llvm::raw_svector_ostream Out(OutName);
219 // Don't specify signed/unsigned since integer types can alias despite sign
220 // differences.
221 Out << "_BitInt(" << EIT->getNumBits() << ')';
222 return createScalarTypeNode(OutName, getChar(), Size);
223 }
224
225 // For now, handle any other kind of type conservatively.
226 return getChar();
227}
228
230 // At -O0 or relaxed aliasing, TBAA is not emitted for regular types.
231 if (CodeGenOpts.OptimizationLevel == 0 || CodeGenOpts.RelaxedAliasing)
232 return nullptr;
233
234 // If the type has the may_alias attribute (even on a typedef), it is
235 // effectively in the general char alias class.
236 if (TypeHasMayAlias(QTy))
237 return getChar();
238
239 // We need this function to not fall back to returning the "omnipotent char"
240 // type node for aggregate and union types. Otherwise, any dereference of an
241 // aggregate will result into the may-alias access descriptor, meaning all
242 // subsequent accesses to direct and indirect members of that aggregate will
243 // be considered may-alias too.
244 // TODO: Combine getTypeInfo() and getValidBaseTypeInfo() into a single
245 // function.
246 if (isValidBaseType(QTy))
247 return getValidBaseTypeInfo(QTy);
248
249 const Type *Ty = Context.getCanonicalType(QTy).getTypePtr();
250 if (llvm::MDNode *N = MetadataCache[Ty])
251 return N;
252
253 // Note that the following helper call is allowed to add new nodes to the
254 // cache, which invalidates all its previously obtained iterators. So we
255 // first generate the node for the type and then add that node to the cache.
256 llvm::MDNode *TypeNode = getTypeInfoHelper(Ty);
257 return MetadataCache[Ty] = TypeNode;
258}
259
261 // Pointee values may have incomplete types, but they shall never be
262 // dereferenced.
263 if (AccessType->isIncompleteType())
265
266 if (TypeHasMayAlias(AccessType))
268
269 uint64_t Size = Context.getTypeSizeInChars(AccessType).getQuantity();
270 return TBAAAccessInfo(getTypeInfo(AccessType), Size);
271}
272
274 llvm::DataLayout DL(&Module);
275 unsigned Size = DL.getPointerTypeSize(VTablePtrType);
276 return TBAAAccessInfo(createScalarTypeNode("vtable pointer", getRoot(), Size),
277 Size);
278}
279
280bool
281CodeGenTBAA::CollectFields(uint64_t BaseOffset,
282 QualType QTy,
284 Fields,
285 bool MayAlias) {
286 /* Things not handled yet include: C++ base classes, bitfields, */
287
288 if (const RecordType *TTy = QTy->getAs<RecordType>()) {
289 if (TTy->isUnionType()) {
290 uint64_t Size = Context.getTypeSizeInChars(QTy).getQuantity();
291 llvm::MDNode *TBAAType = getChar();
292 llvm::MDNode *TBAATag = getAccessTagInfo(TBAAAccessInfo(TBAAType, Size));
293 Fields.push_back(
294 llvm::MDBuilder::TBAAStructField(BaseOffset, Size, TBAATag));
295 return true;
296 }
297 const RecordDecl *RD = TTy->getDecl()->getDefinition();
298 if (RD->hasFlexibleArrayMember())
299 return false;
300
301 // TODO: Handle C++ base classes.
302 if (const CXXRecordDecl *Decl = dyn_cast<CXXRecordDecl>(RD))
303 if (Decl->bases_begin() != Decl->bases_end())
304 return false;
305
306 const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
307 const CGRecordLayout &CGRL = CGTypes.getCGRecordLayout(RD);
308
309 unsigned idx = 0;
310 for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
311 i != e; ++i, ++idx) {
312 if ((*i)->isZeroSize(Context))
313 continue;
314
315 uint64_t Offset =
316 BaseOffset + Layout.getFieldOffset(idx) / Context.getCharWidth();
317
318 // Create a single field for consecutive named bitfields using char as
319 // base type.
320 if ((*i)->isBitField()) {
321 const CGBitFieldInfo &Info = CGRL.getBitFieldInfo(*i);
322 // For big endian targets the first bitfield in the consecutive run is
323 // at the most-significant end; see CGRecordLowering::setBitFieldInfo
324 // for more information.
325 bool IsBE = Context.getTargetInfo().isBigEndian();
326 bool IsFirst = IsBE ? Info.StorageSize - (Info.Offset + Info.Size) == 0
327 : Info.Offset == 0;
328 if (!IsFirst)
329 continue;
330 unsigned CurrentBitFieldSize = Info.StorageSize;
331 uint64_t Size =
332 llvm::divideCeil(CurrentBitFieldSize, Context.getCharWidth());
333 llvm::MDNode *TBAAType = getChar();
334 llvm::MDNode *TBAATag =
335 getAccessTagInfo(TBAAAccessInfo(TBAAType, Size));
336 Fields.push_back(
337 llvm::MDBuilder::TBAAStructField(Offset, Size, TBAATag));
338 continue;
339 }
340
341 QualType FieldQTy = i->getType();
342 if (!CollectFields(Offset, FieldQTy, Fields,
343 MayAlias || TypeHasMayAlias(FieldQTy)))
344 return false;
345 }
346 return true;
347 }
348
349 /* Otherwise, treat whatever it is as a field. */
350 uint64_t Offset = BaseOffset;
352 llvm::MDNode *TBAAType = MayAlias ? getChar() : getTypeInfo(QTy);
353 llvm::MDNode *TBAATag = getAccessTagInfo(TBAAAccessInfo(TBAAType, Size));
354 Fields.push_back(llvm::MDBuilder::TBAAStructField(Offset, Size, TBAATag));
355 return true;
356}
357
358llvm::MDNode *
360 if (CodeGenOpts.OptimizationLevel == 0 || CodeGenOpts.RelaxedAliasing)
361 return nullptr;
362
363 const Type *Ty = Context.getCanonicalType(QTy).getTypePtr();
364
365 if (llvm::MDNode *N = StructMetadataCache[Ty])
366 return N;
367
369 if (CollectFields(0, QTy, Fields, TypeHasMayAlias(QTy)))
370 return MDHelper.createTBAAStructNode(Fields);
371
372 // For now, handle any other kind of type conservatively.
373 return StructMetadataCache[Ty] = nullptr;
374}
375
376llvm::MDNode *CodeGenTBAA::getBaseTypeInfoHelper(const Type *Ty) {
377 if (auto *TTy = dyn_cast<RecordType>(Ty)) {
378 const RecordDecl *RD = TTy->getDecl()->getDefinition();
379 const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
380 using TBAAStructField = llvm::MDBuilder::TBAAStructField;
382 if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
383 // Handle C++ base classes. Non-virtual bases can treated a kind of
384 // field. Virtual bases are more complex and omitted, but avoid an
385 // incomplete view for NewStructPathTBAA.
386 if (CodeGenOpts.NewStructPathTBAA && CXXRD->getNumVBases() != 0)
387 return nullptr;
388 for (const CXXBaseSpecifier &B : CXXRD->bases()) {
389 if (B.isVirtual())
390 continue;
391 QualType BaseQTy = B.getType();
392 const CXXRecordDecl *BaseRD = BaseQTy->getAsCXXRecordDecl();
393 if (BaseRD->isEmpty())
394 continue;
395 llvm::MDNode *TypeNode = isValidBaseType(BaseQTy)
396 ? getValidBaseTypeInfo(BaseQTy)
397 : getTypeInfo(BaseQTy);
398 if (!TypeNode)
399 return nullptr;
400 uint64_t Offset = Layout.getBaseClassOffset(BaseRD).getQuantity();
401 uint64_t Size =
402 Context.getASTRecordLayout(BaseRD).getDataSize().getQuantity();
403 Fields.push_back(
404 llvm::MDBuilder::TBAAStructField(Offset, Size, TypeNode));
405 }
406 // The order in which base class subobjects are allocated is unspecified,
407 // so may differ from declaration order. In particular, Itanium ABI will
408 // allocate a primary base first.
409 // Since we exclude empty subobjects, the objects are not overlapping and
410 // their offsets are unique.
411 llvm::sort(Fields,
412 [](const TBAAStructField &A, const TBAAStructField &B) {
413 return A.Offset < B.Offset;
414 });
415 }
416 for (FieldDecl *Field : RD->fields()) {
417 if (Field->isZeroSize(Context) || Field->isUnnamedBitField())
418 continue;
419 QualType FieldQTy = Field->getType();
420 llvm::MDNode *TypeNode = isValidBaseType(FieldQTy)
421 ? getValidBaseTypeInfo(FieldQTy)
422 : getTypeInfo(FieldQTy);
423 if (!TypeNode)
424 return nullptr;
425
426 uint64_t BitOffset = Layout.getFieldOffset(Field->getFieldIndex());
427 uint64_t Offset = Context.toCharUnitsFromBits(BitOffset).getQuantity();
428 uint64_t Size = Context.getTypeSizeInChars(FieldQTy).getQuantity();
429 Fields.push_back(llvm::MDBuilder::TBAAStructField(Offset, Size,
430 TypeNode));
431 }
432
433 SmallString<256> OutName;
434 if (Features.CPlusPlus) {
435 // Don't use the mangler for C code.
436 llvm::raw_svector_ostream Out(OutName);
437 MContext.mangleCanonicalTypeName(QualType(Ty, 0), Out);
438 } else {
439 OutName = RD->getName();
440 }
441
442 if (CodeGenOpts.NewStructPathTBAA) {
443 llvm::MDNode *Parent = getChar();
445 llvm::Metadata *Id = MDHelper.createString(OutName);
446 return MDHelper.createTBAATypeNode(Parent, Size, Id, Fields);
447 }
448
449 // Create the struct type node with a vector of pairs (offset, type).
451 for (const auto &Field : Fields)
452 OffsetsAndTypes.push_back(std::make_pair(Field.Type, Field.Offset));
453 return MDHelper.createTBAAStructTypeNode(OutName, OffsetsAndTypes);
454 }
455
456 return nullptr;
457}
458
459llvm::MDNode *CodeGenTBAA::getValidBaseTypeInfo(QualType QTy) {
460 assert(isValidBaseType(QTy) && "Must be a valid base type");
461
462 const Type *Ty = Context.getCanonicalType(QTy).getTypePtr();
463
464 // nullptr is a valid value in the cache, so use find rather than []
465 auto I = BaseTypeMetadataCache.find(Ty);
466 if (I != BaseTypeMetadataCache.end())
467 return I->second;
468
469 // First calculate the metadata, before recomputing the insertion point, as
470 // the helper can recursively call us.
471 llvm::MDNode *TypeNode = getBaseTypeInfoHelper(Ty);
472 LLVM_ATTRIBUTE_UNUSED auto inserted =
473 BaseTypeMetadataCache.insert({Ty, TypeNode});
474 assert(inserted.second && "BaseType metadata was already inserted");
475
476 return TypeNode;
477}
478
480 return isValidBaseType(QTy) ? getValidBaseTypeInfo(QTy) : nullptr;
481}
482
484 assert(!Info.isIncomplete() && "Access to an object of an incomplete type!");
485
486 if (Info.isMayAlias())
487 Info = TBAAAccessInfo(getChar(), Info.Size);
488
489 if (!Info.AccessType)
490 return nullptr;
491
492 if (!CodeGenOpts.StructPathTBAA)
493 Info = TBAAAccessInfo(Info.AccessType, Info.Size);
494
495 llvm::MDNode *&N = AccessTagMetadataCache[Info];
496 if (N)
497 return N;
498
499 if (!Info.BaseType) {
500 Info.BaseType = Info.AccessType;
501 assert(!Info.Offset && "Nonzero offset for an access with no base type!");
502 }
503 if (CodeGenOpts.NewStructPathTBAA) {
504 return N = MDHelper.createTBAAAccessTag(Info.BaseType, Info.AccessType,
505 Info.Offset, Info.Size);
506 }
507 return N = MDHelper.createTBAAStructTagNode(Info.BaseType, Info.AccessType,
508 Info.Offset);
509}
510
513 if (SourceInfo.isMayAlias() || TargetInfo.isMayAlias())
515 return TargetInfo;
516}
517
520 TBAAAccessInfo InfoB) {
521 if (InfoA == InfoB)
522 return InfoA;
523
524 if (!InfoA || !InfoB)
525 return TBAAAccessInfo();
526
527 if (InfoA.isMayAlias() || InfoB.isMayAlias())
529
530 // TODO: Implement the rest of the logic here. For example, two accesses
531 // with same final access types result in an access to an object of that final
532 // access type regardless of their base types.
534}
535
538 TBAAAccessInfo SrcInfo) {
539 if (DestInfo == SrcInfo)
540 return DestInfo;
541
542 if (!DestInfo || !SrcInfo)
543 return TBAAAccessInfo();
544
545 if (DestInfo.isMayAlias() || SrcInfo.isMayAlias())
547
548 // TODO: Implement the rest of the logic here. For example, two accesses
549 // with same final access types result in an access to an object of that final
550 // access type regardless of their base types.
552}
Defines the clang::ASTContext interface.
NodeId Parent
Definition: ASTDiff.cpp:191
static bool TypeHasMayAlias(QualType QTy)
Definition: CodeGenTBAA.cpp:82
static bool isValidBaseType(QualType QTy)
Check if the given type is a valid base type to be used in access tags.
uint32_t Id
Definition: SemaARM.cpp:1143
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:186
CanQualType AccumTy
Definition: ASTContext.h:1122
CanQualType LongTy
Definition: ASTContext.h:1118
CanQualType Int128Ty
Definition: ASTContext.h:1118
CanQualType SatAccumTy
Definition: ASTContext.h:1127
CanQualType ShortAccumTy
Definition: ASTContext.h:1122
const ASTRecordLayout & getASTRecordLayout(const RecordDecl *D) const
Get or compute information about the layout of the specified record (struct/union/class) D,...
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2616
CanQualType SatLongAccumTy
Definition: ASTContext.h:1127
CanQualType SatShortFractTy
Definition: ASTContext.h:1130
CanQualType ShortFractTy
Definition: ASTContext.h:1125
CanQualType IntTy
Definition: ASTContext.h:1118
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
CanQualType ShortTy
Definition: ASTContext.h:1118
CanQualType FractTy
Definition: ASTContext.h:1125
CanQualType LongAccumTy
Definition: ASTContext.h:1123
CanQualType SatFractTy
Definition: ASTContext.h:1130
CanQualType SatLongFractTy
Definition: ASTContext.h:1130
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:769
CanQualType LongFractTy
Definition: ASTContext.h:1125
CanQualType SatShortAccumTy
Definition: ASTContext.h:1127
CharUnits toCharUnitsFromBits(int64_t BitSize) const
Convert a size in bits to a size in characters.
CanQualType LongLongTy
Definition: ASTContext.h:1118
uint64_t getCharWidth() const
Return the size of the character type, in bits.
Definition: ASTContext.h:2386
ASTRecordLayout - This class contains layout information for one RecordDecl, which is a struct/union/...
Definition: RecordLayout.h:38
uint64_t getFieldOffset(unsigned FieldNo) const
getFieldOffset - Get the offset of the given field index, in bits.
Definition: RecordLayout.h:200
CharUnits getDataSize() const
getDataSize() - Get the record data size, which is the record size without tail padding,...
Definition: RecordLayout.h:206
CharUnits getBaseClassOffset(const CXXRecordDecl *Base) const
getBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:249
This class is used for builtin types like 'int'.
Definition: Type.h:2997
Represents a base class of a C++ class.
Definition: DeclCXX.h:146
Represents a C++ struct/union/class.
Definition: DeclCXX.h:258
bool isEmpty() const
Determine whether this is an empty class in the sense of (C++11 [meta.unary.prop]).
Definition: DeclCXX.h:1190
const T * getTypePtr() const
Retrieve the underlying type pointer, which refers to a canonical type.
Definition: CanonicalType.h:83
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:185
CodeGenOptions - Track various options which control how the code is optimized and passed to the back...
CGRecordLayout - This class handles struct and union layout info while lowering AST types to LLVM typ...
const CGBitFieldInfo & getBitFieldInfo(const FieldDecl *FD) const
Return the BitFieldInfo that corresponds to the field FD.
llvm::MDNode * getBaseTypeInfo(QualType QTy)
getBaseTypeInfo - Get metadata that describes the given base access type.
llvm::MDNode * getTypeInfo(QualType QTy)
getTypeInfo - Get metadata used to describe accesses to objects of the given type.
TBAAAccessInfo getVTablePtrAccessInfo(llvm::Type *VTablePtrType)
getVTablePtrAccessInfo - Get the TBAA information that describes an access to a virtual table pointer...
TBAAAccessInfo mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo, TBAAAccessInfo SrcInfo)
mergeTBAAInfoForMemoryTransfer - Get merged TBAA information for the purpose of memory transfer calls...
TBAAAccessInfo mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo, TBAAAccessInfo TargetInfo)
mergeTBAAInfoForCast - Get merged TBAA information for the purpose of type casts.
TBAAAccessInfo mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA, TBAAAccessInfo InfoB)
mergeTBAAInfoForConditionalOperator - Get merged TBAA information for the purpose of conditional oper...
llvm::MDNode * getAccessTagInfo(TBAAAccessInfo Info)
getAccessTagInfo - Get TBAA tag for a given memory access.
llvm::MDNode * getTBAAStructInfo(QualType QTy)
getTBAAStructInfo - Get the TBAAStruct MDNode to be used for a memcpy of the given type.
CodeGenTBAA(ASTContext &Ctx, CodeGenTypes &CGTypes, llvm::Module &M, const CodeGenOptions &CGO, const LangOptions &Features, MangleContext &MContext)
Definition: CodeGenTBAA.cpp:36
TBAAAccessInfo getAccessInfo(QualType AccessType)
getAccessInfo - Get TBAA information that describes an access to an object of the given type.
This class organizes the cross-module state that is used while lowering AST types to LLVM types.
Definition: CodeGenTypes.h:54
const CGRecordLayout & getCGRecordLayout(const RecordDecl *)
getCGRecordLayout - Return record layout info for the given record decl.
specific_decl_iterator - Iterates over a subrange of declarations stored in a DeclContext,...
Definition: DeclBase.h:2335
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of enums.
Definition: Type.h:5963
Represents a member of a struct/union/class.
Definition: Decl.h:3069
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:461
MangleContext - Context for tracking state which persists across multiple calls to the C++ name mangl...
Definition: Mangle.h:45
virtual void mangleCanonicalTypeName(QualType T, raw_ostream &, bool NormalizeIntegers=false)=0
Generates a unique string for an externally visible type for use with TBAA or type uniquing.
Describes a module or submodule.
Definition: Module.h:105
StringRef getName() const
Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:276
A (possibly-)qualified type.
Definition: Type.h:942
Represents a struct/union/class.
Definition: Decl.h:4180
bool hasFlexibleArrayMember() const
Definition: Decl.h:4213
field_iterator field_end() const
Definition: Decl.h:4389
field_range fields() const
Definition: Decl.h:4386
RecordDecl * getDefinition() const
Returns the RecordDecl that actually defines this struct/union/class.
Definition: Decl.h:4371
field_iterator field_begin() const
Definition: Decl.cpp:5057
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:5937
bool isStruct() const
Definition: Decl.h:3799
bool isClass() const
Definition: Decl.h:3801
Exposes information about the current target.
Definition: TargetInfo.h:218
bool isBigEndian() const
Definition: TargetInfo.h:1665
The base class of the type hierarchy.
Definition: Type.h:1826
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1881
bool isArrayType() const
Definition: Type.h:8065
bool isPointerType() const
Definition: Type.h:7997
bool isReferenceType() const
Definition: Type.h:8011
bool isStdByteType() const
Definition: Type.cpp:3075
bool isIncompleteType(NamedDecl **Def=nullptr) const
Types are partitioned into 3 broad categories (C99 6.2.5p1): object types, function types,...
Definition: Type.cpp:2361
const T * getAs() const
Member-template getAs<specific type>'.
Definition: Type.h:8517
TagDecl * getAsTagDecl() const
Retrieves the TagDecl that this type refers to, either because the type is a TagType or because it is...
Definition: Type.cpp:1889
Defines the clang::TargetInfo interface.
The JSON file list parser is used to communicate input to InstallAPI.
if(T->getSizeExpr()) TRY_TO(TraverseStmt(const_cast< Expr * >(T -> getSizeExpr())))
unsigned long uint64_t
Structure with information about how a bitfield should be accessed.
unsigned Offset
The offset within a contiguous run of bitfields that are represented as a single "field" within the L...
unsigned Size
The total size of the bit-field, in bits.
unsigned StorageSize
The storage size in bits which should be used when accessing this bitfield.
llvm::MDNode * AccessType
AccessType - The final access type.
Definition: CodeGenTBAA.h:105
uint64_t Offset
Offset - The byte offset of the final access within the base one.
Definition: CodeGenTBAA.h:109
static TBAAAccessInfo getMayAliasInfo()
Definition: CodeGenTBAA.h:63
uint64_t Size
Size - The size of access, in bytes.
Definition: CodeGenTBAA.h:112
static TBAAAccessInfo getIncompleteInfo()
Definition: CodeGenTBAA.h:71
llvm::MDNode * BaseType
BaseType - The base/leading access type.
Definition: CodeGenTBAA.h:101