diff --git a/lld/COFF/InputFiles.cpp b/lld/COFF/InputFiles.cpp index a9c4ec426c51..1d76eaa46313 100644 --- a/lld/COFF/InputFiles.cpp +++ b/lld/COFF/InputFiles.cpp @@ -158,23 +158,12 @@ std::error_code ObjectFile::initializeSymbols() { } COFFSymbolRef Sym = SymOrErr.get(); - // Get a symbol name. - StringRef SymbolName; - if (auto EC = COFFObj->getSymbolName(Sym, SymbolName)) { - llvm::errs() << "broken object file: " << getName() << ": " - << EC.message() << "\n"; - return make_error_code(LLDError::BrokenFile); - } - // Skip special symbols. - if (SymbolName == "@comp.id" || SymbolName == "@feat.00") - continue; - const void *AuxP = nullptr; if (Sym.getNumberOfAuxSymbols()) AuxP = COFFObj->getSymbol(I + 1)->getRawPtr(); bool IsFirst = (LastSectionNumber != Sym.getSectionNumber()); - SymbolBody *Body = createSymbolBody(SymbolName, Sym, AuxP, IsFirst); + SymbolBody *Body = createSymbolBody(Sym, AuxP, IsFirst); if (Body) { SymbolBodies.push_back(Body); SparseSymbolBodies[I] = Body; @@ -185,19 +174,28 @@ std::error_code ObjectFile::initializeSymbols() { return std::error_code(); } -SymbolBody *ObjectFile::createSymbolBody(StringRef Name, COFFSymbolRef Sym, - const void *AuxP, bool IsFirst) { - if (Sym.isUndefined()) +SymbolBody *ObjectFile::createSymbolBody(COFFSymbolRef Sym, const void *AuxP, + bool IsFirst) { + StringRef Name; + if (Sym.isUndefined()) { + COFFObj->getSymbolName(Sym, Name); return new (Alloc) Undefined(Name); + } if (Sym.isCommon()) { Chunk *C = new (Alloc) CommonChunk(Sym); Chunks.push_back(C); - return new (Alloc) DefinedRegular(Name, Sym, C); + return new (Alloc) DefinedRegular(COFFObj.get(), Sym, C); } - if (Sym.isAbsolute()) + if (Sym.isAbsolute()) { + COFFObj->getSymbolName(Sym, Name); + // Skip special symbols. + if (Name == "@comp.id" || Name == "@feat.00") + return nullptr; return new (Alloc) DefinedAbsolute(Name, Sym.getValue()); + } // TODO: Handle IMAGE_WEAK_EXTERN_SEARCH_ALIAS if (Sym.isWeakExternal()) { + COFFObj->getSymbolName(Sym, Name); auto *Aux = (const coff_aux_weak_external *)AuxP; return new (Alloc) Undefined(Name, &SparseSymbolBodies[Aux->TagIndex]); } @@ -214,7 +212,7 @@ SymbolBody *ObjectFile::createSymbolBody(StringRef Name, COFFSymbolRef Sym, } } if (Chunk *C = SparseChunks[Sym.getSectionNumber()]) - return new (Alloc) DefinedRegular(Name, Sym, C); + return new (Alloc) DefinedRegular(COFFObj.get(), Sym, C); return nullptr; } diff --git a/lld/COFF/InputFiles.h b/lld/COFF/InputFiles.h index 819238ff23d3..9b46e8f953a6 100644 --- a/lld/COFF/InputFiles.h +++ b/lld/COFF/InputFiles.h @@ -111,8 +111,8 @@ private: std::error_code initializeChunks(); std::error_code initializeSymbols(); - SymbolBody *createSymbolBody(StringRef Name, COFFSymbolRef Sym, - const void *Aux, bool IsFirst); + SymbolBody *createSymbolBody(COFFSymbolRef Sym, const void *Aux, + bool IsFirst); std::unique_ptr COFFObj; StringRef Directives; diff --git a/lld/COFF/Symbols.cpp b/lld/COFF/Symbols.cpp index 30e219bf11ac..864db01ae08e 100644 --- a/lld/COFF/Symbols.cpp +++ b/lld/COFF/Symbols.cpp @@ -69,6 +69,19 @@ int Undefined::compare(SymbolBody *Other) { return 1; } +StringRef DefinedRegular::getName() { + // DefinedSymbol's name is read lazily for a performance reason. + // Non-external symbol names are never used by the linker. + // Their internal references are resolved not by name but by symbol index. + // And because they are not external, no one can refer them by name. + // Object files contain lots of non-external symbols, and creating + // StringRefs for them (which involves lots of strlen() on the string table) + // is a waste of time. + if (Name.empty()) + COFFFile->getSymbolName(Sym, Name); + return Name; +} + ErrorOr> Lazy::getMember() { auto MBRefOrErr = File->getMember(&Sym); if (auto EC = MBRefOrErr.getError()) diff --git a/lld/COFF/Symbols.h b/lld/COFF/Symbols.h index 141a3f886e73..316e3a3bb0bf 100644 --- a/lld/COFF/Symbols.h +++ b/lld/COFF/Symbols.h @@ -23,6 +23,7 @@ namespace lld { namespace coff { using llvm::object::Archive; +using llvm::object::COFFObjectFile; using llvm::object::COFFSymbolRef; using llvm::object::coff_import_header; @@ -61,7 +62,7 @@ public: virtual bool isExternal() { return true; } // Returns the symbol name. - StringRef getName() { return Name; } + virtual StringRef getName() = 0; // A SymbolBody has a backreference to a Symbol. Originally they are // doubly-linked. A backreference will never change. But the pointer @@ -78,11 +79,10 @@ public: virtual int compare(SymbolBody *Other) = 0; protected: - SymbolBody(Kind K, StringRef N) : SymbolKind(K), Name(N) {} + SymbolBody(Kind K) : SymbolKind(K) {} private: const Kind SymbolKind; - StringRef Name; Symbol *Backref = nullptr; }; @@ -90,7 +90,7 @@ private: // etc. class Defined : public SymbolBody { public: - Defined(Kind K, StringRef Name) : SymbolBody(K, Name) {} + Defined(Kind K) : SymbolBody(K) {} static bool classof(const SymbolBody *S) { Kind K = S->kind(); @@ -115,13 +115,14 @@ public: // Regular defined symbols read from object file symbol tables. class DefinedRegular : public Defined { public: - DefinedRegular(StringRef Name, COFFSymbolRef S, Chunk *C) - : Defined(DefinedRegularKind, Name), Sym(S), Data(C) {} + DefinedRegular(COFFObjectFile *F, COFFSymbolRef S, Chunk *C) + : Defined(DefinedRegularKind), COFFFile(F), Sym(S), Data(C) {} static bool classof(const SymbolBody *S) { return S->kind() == DefinedRegularKind; } + StringRef getName() override; uint64_t getRVA() override { return Data->getRVA() + Sym.getValue(); } bool isExternal() override { return Sym.isExternal(); } void markLive() override { Data->markLive(); } @@ -133,6 +134,8 @@ public: uint32_t getCommonSize() const { return Sym.getValue(); } private: + StringRef Name; + COFFObjectFile *COFFFile; COFFSymbolRef Sym; Chunk *Data; }; @@ -140,17 +143,19 @@ private: // Absolute symbols. class DefinedAbsolute : public Defined { public: - DefinedAbsolute(StringRef Name, uint64_t VA) - : Defined(DefinedAbsoluteKind, Name), RVA(VA - Config->ImageBase) {} + DefinedAbsolute(StringRef N, uint64_t VA) + : Defined(DefinedAbsoluteKind), Name(N), RVA(VA - Config->ImageBase) {} static bool classof(const SymbolBody *S) { return S->kind() == DefinedAbsoluteKind; } + StringRef getName() override { return Name; } uint64_t getRVA() override { return RVA; } uint64_t getFileOff() override { llvm_unreachable("internal error"); } private: + StringRef Name; uint64_t RVA; }; @@ -162,9 +167,10 @@ private: class Lazy : public SymbolBody { public: Lazy(ArchiveFile *F, const Archive::Symbol S) - : SymbolBody(LazyKind, S.getName()), File(F), Sym(S) {} + : SymbolBody(LazyKind), Name(S.getName()), File(F), Sym(S) {} static bool classof(const SymbolBody *S) { return S->kind() == LazyKind; } + StringRef getName() override { return Name; } // Returns an object file for this symbol, or a nullptr if the file // was already returned. @@ -173,6 +179,7 @@ public: int compare(SymbolBody *Other) override; private: + StringRef Name; ArchiveFile *File; const Archive::Symbol Sym; }; @@ -180,12 +187,13 @@ private: // Undefined symbols. class Undefined : public SymbolBody { public: - explicit Undefined(StringRef Name, SymbolBody **S = nullptr) - : SymbolBody(UndefinedKind, Name), Alias(S) {} + explicit Undefined(StringRef N, SymbolBody **S = nullptr) + : SymbolBody(UndefinedKind), Name(N), Alias(S) {} static bool classof(const SymbolBody *S) { return S->kind() == UndefinedKind; } + StringRef getName() override { return Name; } // An undefined symbol can have a fallback symbol which gives an // undefined symbol a second chance if it would remain undefined. @@ -196,6 +204,7 @@ public: int compare(SymbolBody *Other) override; private: + StringRef Name; SymbolBody **Alias; }; @@ -207,15 +216,16 @@ private: // table in an output. The former has "__imp_" prefix. class DefinedImportData : public Defined { public: - DefinedImportData(StringRef D, StringRef Name, StringRef E, + DefinedImportData(StringRef D, StringRef N, StringRef E, const coff_import_header *H) - : Defined(DefinedImportDataKind, Name), DLLName(D), - ExternalName(E), Hdr(H) {} + : Defined(DefinedImportDataKind), Name(N), DLLName(D), ExternalName(E), + Hdr(H) {} static bool classof(const SymbolBody *S) { return S->kind() == DefinedImportDataKind; } + StringRef getName() override { return Name; } uint64_t getRVA() override { return Location->getRVA(); } uint64_t getFileOff() override { return Location->getFileOff(); } StringRef getDLLName() { return DLLName; } @@ -224,6 +234,7 @@ public: uint16_t getOrdinal() { return Hdr->OrdinalHint; } private: + StringRef Name; StringRef DLLName; StringRef ExternalName; const coff_import_header *Hdr; @@ -237,31 +248,37 @@ private: // a regular name. A function pointer is given as a DefinedImportData. class DefinedImportThunk : public Defined { public: - DefinedImportThunk(StringRef Name, DefinedImportData *S) - : Defined(DefinedImportThunkKind, Name), Data(S) {} + DefinedImportThunk(StringRef N, DefinedImportData *S) + : Defined(DefinedImportThunkKind), Name(N), Data(S) {} static bool classof(const SymbolBody *S) { return S->kind() == DefinedImportThunkKind; } + StringRef getName() override { return Name; } uint64_t getRVA() override { return Data.getRVA(); } uint64_t getFileOff() override { return Data.getFileOff(); } Chunk *getChunk() { return &Data; } private: + StringRef Name; ImportThunkChunk Data; }; class DefinedBitcode : public Defined { public: - DefinedBitcode(StringRef Name) : Defined(DefinedBitcodeKind, Name) {} + DefinedBitcode(StringRef N) : Defined(DefinedBitcodeKind), Name(N) {} static bool classof(const SymbolBody *S) { return S->kind() == DefinedBitcodeKind; } + StringRef getName() override { return Name; } uint64_t getRVA() override { llvm_unreachable("bitcode reached writer"); } uint64_t getFileOff() override { llvm_unreachable("bitcode reached writer"); } + +private: + StringRef Name; }; } // namespace coff