| //===- IdentifierResolver.cpp - Lexical Scope Name lookup -------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the IdentifierResolver class, which is used for lexical |
| // scoped lookup, based on declaration names. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Sema/IdentifierResolver.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/Basic/LangOptions.h" |
| #include "clang/Lex/ExternalPreprocessorSource.h" |
| #include "clang/Lex/Preprocessor.h" |
| #include "clang/Sema/Scope.h" |
| |
| using namespace clang; |
| |
| //===----------------------------------------------------------------------===// |
| // IdDeclInfoMap class |
| //===----------------------------------------------------------------------===// |
| |
| /// IdDeclInfoMap - Associates IdDeclInfos with declaration names. |
| /// Allocates 'pools' (vectors of IdDeclInfos) to avoid allocating each |
| /// individual IdDeclInfo to heap. |
| class IdentifierResolver::IdDeclInfoMap { |
| static const unsigned int POOL_SIZE = 512; |
| |
| /// We use our own linked-list implementation because it is sadly |
| /// impossible to add something to a pre-C++0x STL container without |
| /// a completely unnecessary copy. |
| struct IdDeclInfoPool { |
| IdDeclInfoPool(IdDeclInfoPool *Next) : Next(Next) {} |
| |
| IdDeclInfoPool *Next; |
| IdDeclInfo Pool[POOL_SIZE]; |
| }; |
| |
| IdDeclInfoPool *CurPool; |
| unsigned int CurIndex; |
| |
| public: |
| IdDeclInfoMap() : CurPool(nullptr), CurIndex(POOL_SIZE) {} |
| |
| ~IdDeclInfoMap() { |
| IdDeclInfoPool *Cur = CurPool; |
| while (IdDeclInfoPool *P = Cur) { |
| Cur = Cur->Next; |
| delete P; |
| } |
| } |
| |
| /// Returns the IdDeclInfo associated to the DeclarationName. |
| /// It creates a new IdDeclInfo if one was not created before for this id. |
| IdDeclInfo &operator[](DeclarationName Name); |
| }; |
| |
| |
| //===----------------------------------------------------------------------===// |
| // IdDeclInfo Implementation |
| //===----------------------------------------------------------------------===// |
| |
| /// RemoveDecl - Remove the decl from the scope chain. |
| /// The decl must already be part of the decl chain. |
| void IdentifierResolver::IdDeclInfo::RemoveDecl(NamedDecl *D) { |
| for (DeclsTy::iterator I = Decls.end(); I != Decls.begin(); --I) { |
| if (D == *(I-1)) { |
| Decls.erase(I-1); |
| return; |
| } |
| } |
| |
| llvm_unreachable("Didn't find this decl on its identifier's chain!"); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // IdentifierResolver Implementation |
| //===----------------------------------------------------------------------===// |
| |
| IdentifierResolver::IdentifierResolver(Preprocessor &PP) |
| : LangOpt(PP.getLangOpts()), PP(PP), |
| IdDeclInfos(new IdDeclInfoMap) { |
| } |
| |
| IdentifierResolver::~IdentifierResolver() { |
| delete IdDeclInfos; |
| } |
| |
| /// isDeclInScope - If 'Ctx' is a function/method, isDeclInScope returns true |
| /// if 'D' is in Scope 'S', otherwise 'S' is ignored and isDeclInScope returns |
| /// true if 'D' belongs to the given declaration context. |
| bool IdentifierResolver::isDeclInScope(Decl *D, DeclContext *Ctx, Scope *S, |
| bool AllowInlineNamespace) const { |
| Ctx = Ctx->getRedeclContext(); |
| |
| if (Ctx->isFunctionOrMethod() || (S && S->isFunctionPrototypeScope())) { |
| // Ignore the scopes associated within transparent declaration contexts. |
| while (S->getEntity() && S->getEntity()->isTransparentContext()) |
| S = S->getParent(); |
| |
| if (S->isDeclScope(D)) |
| return true; |
| if (LangOpt.CPlusPlus) { |
| // C++ 3.3.2p3: |
| // The name declared in a catch exception-declaration is local to the |
| // handler and shall not be redeclared in the outermost block of the |
| // handler. |
| // C++ 3.3.2p4: |
| // Names declared in the for-init-statement, and in the condition of if, |
| // while, for, and switch statements are local to the if, while, for, or |
| // switch statement (including the controlled statement), and shall not be |
| // redeclared in a subsequent condition of that statement nor in the |
| // outermost block (or, for the if statement, any of the outermost blocks) |
| // of the controlled statement. |
| // |
| assert(S->getParent() && "No TUScope?"); |
| if (S->getParent()->getFlags() & Scope::ControlScope) { |
| S = S->getParent(); |
| if (S->isDeclScope(D)) |
| return true; |
| } |
| if (S->getFlags() & Scope::FnTryCatchScope) |
| return S->getParent()->isDeclScope(D); |
| } |
| return false; |
| } |
| |
| // FIXME: If D is a local extern declaration, this check doesn't make sense; |
| // we should be checking its lexical context instead in that case, because |
| // that is its scope. |
| DeclContext *DCtx = D->getDeclContext()->getRedeclContext(); |
| return AllowInlineNamespace ? Ctx->InEnclosingNamespaceSetOf(DCtx) |
| : Ctx->Equals(DCtx); |
| } |
| |
| /// AddDecl - Link the decl to its shadowed decl chain. |
| void IdentifierResolver::AddDecl(NamedDecl *D) { |
| DeclarationName Name = D->getDeclName(); |
| if (IdentifierInfo *II = Name.getAsIdentifierInfo()) |
| updatingIdentifier(*II); |
| |
| void *Ptr = Name.getFETokenInfo<void>(); |
| |
| if (!Ptr) { |
| Name.setFETokenInfo(D); |
| return; |
| } |
| |
| IdDeclInfo *IDI; |
| |
| if (isDeclPtr(Ptr)) { |
| Name.setFETokenInfo(nullptr); |
| IDI = &(*IdDeclInfos)[Name]; |
| NamedDecl *PrevD = static_cast<NamedDecl*>(Ptr); |
| IDI->AddDecl(PrevD); |
| } else |
| IDI = toIdDeclInfo(Ptr); |
| |
| IDI->AddDecl(D); |
| } |
| |
| void IdentifierResolver::InsertDeclAfter(iterator Pos, NamedDecl *D) { |
| DeclarationName Name = D->getDeclName(); |
| if (IdentifierInfo *II = Name.getAsIdentifierInfo()) |
| updatingIdentifier(*II); |
| |
| void *Ptr = Name.getFETokenInfo<void>(); |
| |
| if (!Ptr) { |
| AddDecl(D); |
| return; |
| } |
| |
| if (isDeclPtr(Ptr)) { |
| // We only have a single declaration: insert before or after it, |
| // as appropriate. |
| if (Pos == iterator()) { |
| // Add the new declaration before the existing declaration. |
| NamedDecl *PrevD = static_cast<NamedDecl*>(Ptr); |
| RemoveDecl(PrevD); |
| AddDecl(D); |
| AddDecl(PrevD); |
| } else { |
| // Add new declaration after the existing declaration. |
| AddDecl(D); |
| } |
| |
| return; |
| } |
| |
| // General case: insert the declaration at the appropriate point in the |
| // list, which already has at least two elements. |
| IdDeclInfo *IDI = toIdDeclInfo(Ptr); |
| if (Pos.isIterator()) { |
| IDI->InsertDecl(Pos.getIterator() + 1, D); |
| } else |
| IDI->InsertDecl(IDI->decls_begin(), D); |
| } |
| |
| /// RemoveDecl - Unlink the decl from its shadowed decl chain. |
| /// The decl must already be part of the decl chain. |
| void IdentifierResolver::RemoveDecl(NamedDecl *D) { |
| assert(D && "null param passed"); |
| DeclarationName Name = D->getDeclName(); |
| if (IdentifierInfo *II = Name.getAsIdentifierInfo()) |
| updatingIdentifier(*II); |
| |
| void *Ptr = Name.getFETokenInfo<void>(); |
| |
| assert(Ptr && "Didn't find this decl on its identifier's chain!"); |
| |
| if (isDeclPtr(Ptr)) { |
| assert(D == Ptr && "Didn't find this decl on its identifier's chain!"); |
| Name.setFETokenInfo(nullptr); |
| return; |
| } |
| |
| return toIdDeclInfo(Ptr)->RemoveDecl(D); |
| } |
| |
| /// begin - Returns an iterator for decls with name 'Name'. |
| IdentifierResolver::iterator |
| IdentifierResolver::begin(DeclarationName Name) { |
| if (IdentifierInfo *II = Name.getAsIdentifierInfo()) |
| readingIdentifier(*II); |
| |
| void *Ptr = Name.getFETokenInfo<void>(); |
| if (!Ptr) return end(); |
| |
| if (isDeclPtr(Ptr)) |
| return iterator(static_cast<NamedDecl*>(Ptr)); |
| |
| IdDeclInfo *IDI = toIdDeclInfo(Ptr); |
| |
| IdDeclInfo::DeclsTy::iterator I = IDI->decls_end(); |
| if (I != IDI->decls_begin()) |
| return iterator(I-1); |
| // No decls found. |
| return end(); |
| } |
| |
| namespace { |
| enum DeclMatchKind { |
| DMK_Different, |
| DMK_Replace, |
| DMK_Ignore |
| }; |
| } |
| |
| /// \brief Compare two declarations to see whether they are different or, |
| /// if they are the same, whether the new declaration should replace the |
| /// existing declaration. |
| static DeclMatchKind compareDeclarations(NamedDecl *Existing, NamedDecl *New) { |
| // If the declarations are identical, ignore the new one. |
| if (Existing == New) |
| return DMK_Ignore; |
| |
| // If the declarations have different kinds, they're obviously different. |
| if (Existing->getKind() != New->getKind()) |
| return DMK_Different; |
| |
| // If the declarations are redeclarations of each other, keep the newest one. |
| if (Existing->getCanonicalDecl() == New->getCanonicalDecl()) { |
| // If we're adding an imported declaration, don't replace another imported |
| // declaration. |
| if (Existing->isFromASTFile() && New->isFromASTFile()) |
| return DMK_Different; |
| |
| // If either of these is the most recent declaration, use it. |
| Decl *MostRecent = Existing->getMostRecentDecl(); |
| if (Existing == MostRecent) |
| return DMK_Ignore; |
| |
| if (New == MostRecent) |
| return DMK_Replace; |
| |
| // If the existing declaration is somewhere in the previous declaration |
| // chain of the new declaration, then prefer the new declaration. |
| for (auto RD : New->redecls()) { |
| if (RD == Existing) |
| return DMK_Replace; |
| |
| if (RD->isCanonicalDecl()) |
| break; |
| } |
| |
| return DMK_Ignore; |
| } |
| |
| return DMK_Different; |
| } |
| |
| bool IdentifierResolver::tryAddTopLevelDecl(NamedDecl *D, DeclarationName Name){ |
| if (IdentifierInfo *II = Name.getAsIdentifierInfo()) |
| readingIdentifier(*II); |
| |
| void *Ptr = Name.getFETokenInfo<void>(); |
| |
| if (!Ptr) { |
| Name.setFETokenInfo(D); |
| return true; |
| } |
| |
| IdDeclInfo *IDI; |
| |
| if (isDeclPtr(Ptr)) { |
| NamedDecl *PrevD = static_cast<NamedDecl*>(Ptr); |
| |
| switch (compareDeclarations(PrevD, D)) { |
| case DMK_Different: |
| break; |
| |
| case DMK_Ignore: |
| return false; |
| |
| case DMK_Replace: |
| Name.setFETokenInfo(D); |
| return true; |
| } |
| |
| Name.setFETokenInfo(nullptr); |
| IDI = &(*IdDeclInfos)[Name]; |
| |
| // If the existing declaration is not visible in translation unit scope, |
| // then add the new top-level declaration first. |
| if (!PrevD->getDeclContext()->getRedeclContext()->isTranslationUnit()) { |
| IDI->AddDecl(D); |
| IDI->AddDecl(PrevD); |
| } else { |
| IDI->AddDecl(PrevD); |
| IDI->AddDecl(D); |
| } |
| return true; |
| } |
| |
| IDI = toIdDeclInfo(Ptr); |
| |
| // See whether this declaration is identical to any existing declarations. |
| // If not, find the right place to insert it. |
| for (IdDeclInfo::DeclsTy::iterator I = IDI->decls_begin(), |
| IEnd = IDI->decls_end(); |
| I != IEnd; ++I) { |
| |
| switch (compareDeclarations(*I, D)) { |
| case DMK_Different: |
| break; |
| |
| case DMK_Ignore: |
| return false; |
| |
| case DMK_Replace: |
| *I = D; |
| return true; |
| } |
| |
| if (!(*I)->getDeclContext()->getRedeclContext()->isTranslationUnit()) { |
| // We've found a declaration that is not visible from the translation |
| // unit (it's in an inner scope). Insert our declaration here. |
| IDI->InsertDecl(I, D); |
| return true; |
| } |
| } |
| |
| // Add the declaration to the end. |
| IDI->AddDecl(D); |
| return true; |
| } |
| |
| void IdentifierResolver::readingIdentifier(IdentifierInfo &II) { |
| if (II.isOutOfDate()) |
| PP.getExternalSource()->updateOutOfDateIdentifier(II); |
| } |
| |
| void IdentifierResolver::updatingIdentifier(IdentifierInfo &II) { |
| if (II.isOutOfDate()) |
| PP.getExternalSource()->updateOutOfDateIdentifier(II); |
| |
| if (II.isFromAST()) |
| II.setFETokenInfoChangedSinceDeserialization(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // IdDeclInfoMap Implementation |
| //===----------------------------------------------------------------------===// |
| |
| /// Returns the IdDeclInfo associated to the DeclarationName. |
| /// It creates a new IdDeclInfo if one was not created before for this id. |
| IdentifierResolver::IdDeclInfo & |
| IdentifierResolver::IdDeclInfoMap::operator[](DeclarationName Name) { |
| void *Ptr = Name.getFETokenInfo<void>(); |
| |
| if (Ptr) return *toIdDeclInfo(Ptr); |
| |
| if (CurIndex == POOL_SIZE) { |
| CurPool = new IdDeclInfoPool(CurPool); |
| CurIndex = 0; |
| } |
| IdDeclInfo *IDI = &CurPool->Pool[CurIndex]; |
| Name.setFETokenInfo(reinterpret_cast<void*>( |
| reinterpret_cast<uintptr_t>(IDI) | 0x1) |
| ); |
| ++CurIndex; |
| return *IDI; |
| } |
| |
| void IdentifierResolver::iterator::incrementSlowCase() { |
| NamedDecl *D = **this; |
| void *InfoPtr = D->getDeclName().getFETokenInfo<void>(); |
| assert(!isDeclPtr(InfoPtr) && "Decl with wrong id ?"); |
| IdDeclInfo *Info = toIdDeclInfo(InfoPtr); |
| |
| BaseIter I = getIterator(); |
| if (I != Info->decls_begin()) |
| *this = iterator(I-1); |
| else // No more decls. |
| *this = iterator(); |
| } |