1 //===-- ODRHash.cpp - Hashing to diagnose ODR failures ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 /// This file implements the ODRHash class, which calculates a hash based
12 /// on AST nodes, which is stable across different runs.
14 //===----------------------------------------------------------------------===//
16 #include "clang/AST/ODRHash.h"
18 #include "clang/AST/DeclVisitor.h"
19 #include "clang/AST/NestedNameSpecifier.h"
20 #include "clang/AST/StmtVisitor.h"
21 #include "clang/AST/TypeVisitor.h"
23 using namespace clang;
25 void ODRHash::AddStmt(const Stmt *S) {
26 assert(S && "Expecting non-null pointer.");
27 S->ProcessODRHash(ID, *this);
30 void ODRHash::AddIdentifierInfo(const IdentifierInfo *II) {
31 assert(II && "Expecting non-null pointer.");
32 ID.AddString(II->getName());
35 void ODRHash::AddDeclarationName(DeclarationName Name) {
36 AddBoolean(Name.isEmpty());
40 auto Kind = Name.getNameKind();
43 case DeclarationName::Identifier:
44 AddIdentifierInfo(Name.getAsIdentifierInfo());
46 case DeclarationName::ObjCZeroArgSelector:
47 case DeclarationName::ObjCOneArgSelector:
48 case DeclarationName::ObjCMultiArgSelector: {
49 Selector S = Name.getObjCSelector();
50 AddBoolean(S.isNull());
51 AddBoolean(S.isKeywordSelector());
52 AddBoolean(S.isUnarySelector());
53 unsigned NumArgs = S.getNumArgs();
54 for (unsigned i = 0; i < NumArgs; ++i) {
55 AddIdentifierInfo(S.getIdentifierInfoForSlot(i));
59 case DeclarationName::CXXConstructorName:
60 case DeclarationName::CXXDestructorName:
61 AddQualType(Name.getCXXNameType());
63 case DeclarationName::CXXOperatorName:
64 ID.AddInteger(Name.getCXXOverloadedOperator());
66 case DeclarationName::CXXLiteralOperatorName:
67 AddIdentifierInfo(Name.getCXXLiteralIdentifier());
69 case DeclarationName::CXXConversionFunctionName:
70 AddQualType(Name.getCXXNameType());
72 case DeclarationName::CXXUsingDirective:
74 case DeclarationName::CXXDeductionGuideName: {
75 auto *Template = Name.getCXXDeductionGuideTemplate();
84 void ODRHash::AddNestedNameSpecifier(const NestedNameSpecifier *NNS) {
85 assert(NNS && "Expecting non-null pointer.");
86 const auto *Prefix = NNS->getPrefix();
89 AddNestedNameSpecifier(Prefix);
91 auto Kind = NNS->getKind();
94 case NestedNameSpecifier::Identifier:
95 AddIdentifierInfo(NNS->getAsIdentifier());
97 case NestedNameSpecifier::Namespace:
98 AddDecl(NNS->getAsNamespace());
100 case NestedNameSpecifier::NamespaceAlias:
101 AddDecl(NNS->getAsNamespaceAlias());
103 case NestedNameSpecifier::TypeSpec:
104 case NestedNameSpecifier::TypeSpecWithTemplate:
105 AddType(NNS->getAsType());
107 case NestedNameSpecifier::Global:
108 case NestedNameSpecifier::Super:
113 void ODRHash::AddTemplateName(TemplateName Name) {
114 auto Kind = Name.getKind();
118 case TemplateName::Template:
119 AddDecl(Name.getAsTemplateDecl());
121 // TODO: Support these cases.
122 case TemplateName::OverloadedTemplate:
123 case TemplateName::QualifiedTemplate:
124 case TemplateName::DependentTemplate:
125 case TemplateName::SubstTemplateTemplateParm:
126 case TemplateName::SubstTemplateTemplateParmPack:
131 void ODRHash::AddTemplateArgument(TemplateArgument TA) {
132 const auto Kind = TA.getKind();
136 case TemplateArgument::Null:
137 llvm_unreachable("Expected valid TemplateArgument");
138 case TemplateArgument::Type:
139 AddQualType(TA.getAsType());
141 case TemplateArgument::Declaration:
142 case TemplateArgument::NullPtr:
143 case TemplateArgument::Integral:
145 case TemplateArgument::Template:
146 case TemplateArgument::TemplateExpansion:
147 AddTemplateName(TA.getAsTemplateOrTemplatePattern());
149 case TemplateArgument::Expression:
150 AddStmt(TA.getAsExpr());
152 case TemplateArgument::Pack:
153 ID.AddInteger(TA.pack_size());
154 for (auto SubTA : TA.pack_elements()) {
155 AddTemplateArgument(SubTA);
161 void ODRHash::AddTemplateParameterList(const TemplateParameterList *TPL) {}
163 void ODRHash::clear() {
170 unsigned ODRHash::CalculateHash() {
171 // Append the bools to the end of the data segment backwards. This allows
172 // for the bools data to be compressed 32 times smaller compared to using
174 const unsigned unsigned_bits = sizeof(unsigned) * CHAR_BIT;
175 const unsigned size = Bools.size();
176 const unsigned remainder = size % unsigned_bits;
177 const unsigned loops = size / unsigned_bits;
178 auto I = Bools.rbegin();
180 for (unsigned i = 0; i < remainder; ++i) {
185 ID.AddInteger(value);
187 for (unsigned i = 0; i < loops; ++i) {
189 for (unsigned j = 0; j < unsigned_bits; ++j) {
194 ID.AddInteger(value);
197 assert(I == Bools.rend());
199 return ID.ComputeHash();
202 // Process a Decl pointer. Add* methods call back into ODRHash while Visit*
203 // methods process the relevant parts of the Decl.
204 class ODRDeclVisitor : public ConstDeclVisitor<ODRDeclVisitor> {
205 typedef ConstDeclVisitor<ODRDeclVisitor> Inherited;
206 llvm::FoldingSetNodeID &ID;
210 ODRDeclVisitor(llvm::FoldingSetNodeID &ID, ODRHash &Hash)
211 : ID(ID), Hash(Hash) {}
213 void AddStmt(const Stmt *S) {
220 void AddIdentifierInfo(const IdentifierInfo *II) {
223 Hash.AddIdentifierInfo(II);
227 void AddQualType(QualType T) {
231 void AddDecl(const Decl *D) {
238 void Visit(const Decl *D) {
239 ID.AddInteger(D->getKind());
243 void VisitNamedDecl(const NamedDecl *D) {
244 Hash.AddDeclarationName(D->getDeclName());
245 Inherited::VisitNamedDecl(D);
248 void VisitValueDecl(const ValueDecl *D) {
249 if (!isa<FunctionDecl>(D)) {
250 AddQualType(D->getType());
252 Inherited::VisitValueDecl(D);
255 void VisitVarDecl(const VarDecl *D) {
256 Hash.AddBoolean(D->isStaticLocal());
257 Hash.AddBoolean(D->isConstexpr());
258 const bool HasInit = D->hasInit();
259 Hash.AddBoolean(HasInit);
261 AddStmt(D->getInit());
263 Inherited::VisitVarDecl(D);
266 void VisitParmVarDecl(const ParmVarDecl *D) {
267 // TODO: Handle default arguments.
268 Inherited::VisitParmVarDecl(D);
271 void VisitAccessSpecDecl(const AccessSpecDecl *D) {
272 ID.AddInteger(D->getAccess());
273 Inherited::VisitAccessSpecDecl(D);
276 void VisitStaticAssertDecl(const StaticAssertDecl *D) {
277 AddStmt(D->getAssertExpr());
278 AddStmt(D->getMessage());
280 Inherited::VisitStaticAssertDecl(D);
283 void VisitFieldDecl(const FieldDecl *D) {
284 const bool IsBitfield = D->isBitField();
285 Hash.AddBoolean(IsBitfield);
288 AddStmt(D->getBitWidth());
291 Hash.AddBoolean(D->isMutable());
292 AddStmt(D->getInClassInitializer());
294 Inherited::VisitFieldDecl(D);
297 void VisitFunctionDecl(const FunctionDecl *D) {
298 ID.AddInteger(D->getStorageClass());
299 Hash.AddBoolean(D->isInlineSpecified());
300 Hash.AddBoolean(D->isVirtualAsWritten());
301 Hash.AddBoolean(D->isPure());
302 Hash.AddBoolean(D->isDeletedAsWritten());
304 ID.AddInteger(D->param_size());
306 for (auto *Param : D->parameters()) {
307 Hash.AddSubDecl(Param);
310 AddQualType(D->getReturnType());
312 Inherited::VisitFunctionDecl(D);
315 void VisitCXXMethodDecl(const CXXMethodDecl *D) {
316 Hash.AddBoolean(D->isConst());
317 Hash.AddBoolean(D->isVolatile());
319 Inherited::VisitCXXMethodDecl(D);
322 void VisitTypedefNameDecl(const TypedefNameDecl *D) {
323 AddQualType(D->getUnderlyingType());
325 Inherited::VisitTypedefNameDecl(D);
328 void VisitTypedefDecl(const TypedefDecl *D) {
329 Inherited::VisitTypedefDecl(D);
332 void VisitTypeAliasDecl(const TypeAliasDecl *D) {
333 Inherited::VisitTypeAliasDecl(D);
336 void VisitFriendDecl(const FriendDecl *D) {
337 TypeSourceInfo *TSI = D->getFriendType();
338 Hash.AddBoolean(TSI);
340 AddQualType(TSI->getType());
342 AddDecl(D->getFriendDecl());
347 // Only allow a small portion of Decl's to be processed. Remove this once
348 // all Decl's can be handled.
349 bool ODRHash::isWhitelistedDecl(const Decl *D, const CXXRecordDecl *Parent) {
350 if (D->isImplicit()) return false;
351 if (D->getDeclContext() != Parent) return false;
353 switch (D->getKind()) {
356 case Decl::AccessSpec:
357 case Decl::CXXConstructor:
358 case Decl::CXXDestructor:
359 case Decl::CXXMethod:
362 case Decl::StaticAssert:
363 case Decl::TypeAlias:
370 void ODRHash::AddSubDecl(const Decl *D) {
371 assert(D && "Expecting non-null pointer.");
374 ODRDeclVisitor(ID, *this).Visit(D);
377 void ODRHash::AddCXXRecordDecl(const CXXRecordDecl *Record) {
378 assert(Record && Record->hasDefinition() &&
379 "Expected non-null record to be a definition.");
381 if (isa<ClassTemplateSpecializationDecl>(Record)) {
387 // Filter out sub-Decls which will not be processed in order to get an
388 // accurate count of Decl's.
389 llvm::SmallVector<const Decl *, 16> Decls;
390 for (const Decl *SubDecl : Record->decls()) {
391 if (isWhitelistedDecl(SubDecl, Record)) {
392 Decls.push_back(SubDecl);
396 ID.AddInteger(Decls.size());
397 for (auto SubDecl : Decls) {
402 void ODRHash::AddDecl(const Decl *D) {
403 assert(D && "Expecting non-null pointer.");
404 auto Result = DeclMap.insert(std::make_pair(D, DeclMap.size()));
405 ID.AddInteger(Result.first->second);
406 // On first encounter of a Decl pointer, process it. Every time afterwards,
407 // only the index value is needed.
408 if (!Result.second) {
412 ID.AddInteger(D->getKind());
414 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
415 AddDeclarationName(ND->getDeclName());
419 // Process a Type pointer. Add* methods call back into ODRHash while Visit*
420 // methods process the relevant parts of the Type.
421 class ODRTypeVisitor : public TypeVisitor<ODRTypeVisitor> {
422 typedef TypeVisitor<ODRTypeVisitor> Inherited;
423 llvm::FoldingSetNodeID &ID;
427 ODRTypeVisitor(llvm::FoldingSetNodeID &ID, ODRHash &Hash)
428 : ID(ID), Hash(Hash) {}
430 void AddStmt(Stmt *S) {
437 void AddDecl(Decl *D) {
444 void AddQualType(QualType T) {
448 void AddType(const Type *T) {
455 void AddNestedNameSpecifier(const NestedNameSpecifier *NNS) {
456 Hash.AddBoolean(NNS);
458 Hash.AddNestedNameSpecifier(NNS);
462 void AddIdentifierInfo(const IdentifierInfo *II) {
465 Hash.AddIdentifierInfo(II);
469 void VisitQualifiers(Qualifiers Quals) {
470 ID.AddInteger(Quals.getAsOpaqueValue());
473 void Visit(const Type *T) {
474 ID.AddInteger(T->getTypeClass());
478 void VisitType(const Type *T) {}
480 void VisitAdjustedType(const AdjustedType *T) {
481 AddQualType(T->getOriginalType());
482 AddQualType(T->getAdjustedType());
486 void VisitDecayedType(const DecayedType *T) {
487 AddQualType(T->getDecayedType());
488 AddQualType(T->getPointeeType());
489 VisitAdjustedType(T);
492 void VisitArrayType(const ArrayType *T) {
493 AddQualType(T->getElementType());
494 ID.AddInteger(T->getSizeModifier());
495 VisitQualifiers(T->getIndexTypeQualifiers());
498 void VisitConstantArrayType(const ConstantArrayType *T) {
499 T->getSize().Profile(ID);
503 void VisitDependentSizedArrayType(const DependentSizedArrayType *T) {
504 AddStmt(T->getSizeExpr());
508 void VisitIncompleteArrayType(const IncompleteArrayType *T) {
512 void VisitVariableArrayType(const VariableArrayType *T) {
513 AddStmt(T->getSizeExpr());
517 void VisitBuiltinType(const BuiltinType *T) {
518 ID.AddInteger(T->getKind());
522 void VisitFunctionType(const FunctionType *T) {
523 AddQualType(T->getReturnType());
524 T->getExtInfo().Profile(ID);
525 Hash.AddBoolean(T->isConst());
526 Hash.AddBoolean(T->isVolatile());
527 Hash.AddBoolean(T->isRestrict());
531 void VisitFunctionNoProtoType(const FunctionNoProtoType *T) {
532 VisitFunctionType(T);
535 void VisitFunctionProtoType(const FunctionProtoType *T) {
536 ID.AddInteger(T->getNumParams());
537 for (auto ParamType : T->getParamTypes())
538 AddQualType(ParamType);
540 VisitFunctionType(T);
543 void VisitTypedefType(const TypedefType *T) {
544 AddDecl(T->getDecl());
545 QualType UnderlyingType = T->getDecl()->getUnderlyingType();
546 VisitQualifiers(UnderlyingType.getQualifiers());
547 while (const TypedefType *Underlying =
548 dyn_cast<TypedefType>(UnderlyingType.getTypePtr())) {
549 UnderlyingType = Underlying->getDecl()->getUnderlyingType();
551 AddType(UnderlyingType.getTypePtr());
555 void VisitTagType(const TagType *T) {
556 AddDecl(T->getDecl());
560 void VisitRecordType(const RecordType *T) { VisitTagType(T); }
561 void VisitEnumType(const EnumType *T) { VisitTagType(T); }
563 void VisitTypeWithKeyword(const TypeWithKeyword *T) {
564 ID.AddInteger(T->getKeyword());
568 void VisitDependentNameType(const DependentNameType *T) {
569 AddNestedNameSpecifier(T->getQualifier());
570 AddIdentifierInfo(T->getIdentifier());
571 VisitTypeWithKeyword(T);
574 void VisitDependentTemplateSpecializationType(
575 const DependentTemplateSpecializationType *T) {
576 AddIdentifierInfo(T->getIdentifier());
577 AddNestedNameSpecifier(T->getQualifier());
578 ID.AddInteger(T->getNumArgs());
579 for (const auto &TA : T->template_arguments()) {
580 Hash.AddTemplateArgument(TA);
582 VisitTypeWithKeyword(T);
585 void VisitElaboratedType(const ElaboratedType *T) {
586 AddNestedNameSpecifier(T->getQualifier());
587 AddQualType(T->getNamedType());
588 VisitTypeWithKeyword(T);
591 void VisitTemplateSpecializationType(const TemplateSpecializationType *T) {
592 ID.AddInteger(T->getNumArgs());
593 for (const auto &TA : T->template_arguments()) {
594 Hash.AddTemplateArgument(TA);
596 Hash.AddTemplateName(T->getTemplateName());
600 void VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
601 ID.AddInteger(T->getDepth());
602 ID.AddInteger(T->getIndex());
603 Hash.AddBoolean(T->isParameterPack());
604 AddDecl(T->getDecl());
608 void ODRHash::AddType(const Type *T) {
609 assert(T && "Expecting non-null pointer.");
610 auto Result = TypeMap.insert(std::make_pair(T, TypeMap.size()));
611 ID.AddInteger(Result.first->second);
612 // On first encounter of a Type pointer, process it. Every time afterwards,
613 // only the index value is needed.
614 if (!Result.second) {
618 ODRTypeVisitor(ID, *this).Visit(T);
621 void ODRHash::AddQualType(QualType T) {
622 AddBoolean(T.isNull());
625 SplitQualType split = T.split();
626 ID.AddInteger(split.Quals.getAsOpaqueValue());
630 void ODRHash::AddBoolean(bool Value) {
631 Bools.push_back(Value);