| //===- SymbolTable.h --------------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Linker |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLD_COFF_SYMBOL_TABLE_H |
| #define LLD_COFF_SYMBOL_TABLE_H |
| |
| #include "InputFiles.h" |
| #include "llvm/ADT/CachedHashString.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/DenseMapInfo.h" |
| #include "llvm/Support/Allocator.h" |
| #include "llvm/Support/raw_ostream.h" |
| |
| namespace llvm { |
| struct LTOCodeGenerator; |
| } |
| |
| namespace lld { |
| namespace coff { |
| |
| class Chunk; |
| class CommonChunk; |
| class Defined; |
| class DefinedAbsolute; |
| class DefinedRelative; |
| class Lazy; |
| class SectionChunk; |
| class SymbolBody; |
| struct Symbol; |
| |
| // SymbolTable is a bucket of all known symbols, including defined, |
| // undefined, or lazy symbols (the last one is symbols in archive |
| // files whose archive members are not yet loaded). |
| // |
| // We put all symbols of all files to a SymbolTable, and the |
| // SymbolTable selects the "best" symbols if there are name |
| // conflicts. For example, obviously, a defined symbol is better than |
| // an undefined symbol. Or, if there's a conflict between a lazy and a |
| // undefined, it'll read an archive member to read a real definition |
| // to replace the lazy symbol. The logic is implemented in the |
| // add*() functions, which are called by input files as they are parsed. |
| // There is one add* function per symbol type. |
| class SymbolTable { |
| public: |
| void addFile(InputFile *File); |
| |
| // Try to resolve any undefined symbols and update the symbol table |
| // accordingly, then print an error message for any remaining undefined |
| // symbols. |
| void reportRemainingUndefines(); |
| |
| // Returns a list of chunks of selected symbols. |
| std::vector<Chunk *> getChunks(); |
| |
| // Returns a symbol for a given name. Returns a nullptr if not found. |
| Symbol *find(StringRef Name); |
| Symbol *findUnderscore(StringRef Name); |
| |
| // Occasionally we have to resolve an undefined symbol to its |
| // mangled symbol. This function tries to find a mangled name |
| // for U from the symbol table, and if found, set the symbol as |
| // a weak alias for U. |
| void mangleMaybe(SymbolBody *B); |
| StringRef findMangle(StringRef Name); |
| |
| // Print a layout map to OS. |
| void printMap(llvm::raw_ostream &OS); |
| |
| // Build a set of COFF objects representing the combined contents of |
| // BitcodeFiles and add them to the symbol table. Called after all files are |
| // added and before the writer writes results to a file. |
| void addCombinedLTOObjects(); |
| |
| // The writer needs to handle DLL import libraries specially in |
| // order to create the import descriptor table. |
| std::vector<ImportFile *> ImportFiles; |
| |
| // The writer needs to infer the machine type from the object files. |
| std::vector<ObjectFile *> ObjectFiles; |
| |
| // Creates an Undefined symbol for a given name. |
| SymbolBody *addUndefined(StringRef Name); |
| |
| Symbol *addRelative(StringRef N, uint64_t VA); |
| Symbol *addAbsolute(StringRef N, uint64_t VA); |
| |
| Symbol *addUndefined(StringRef Name, InputFile *F, bool IsWeakAlias); |
| void addLazy(ArchiveFile *F, const Archive::Symbol Sym); |
| Symbol *addAbsolute(StringRef N, COFFSymbolRef S); |
| Symbol *addRegular(ObjectFile *F, COFFSymbolRef S, SectionChunk *C); |
| Symbol *addBitcode(BitcodeFile *F, StringRef N, bool IsReplaceable); |
| Symbol *addCommon(ObjectFile *F, COFFSymbolRef S, CommonChunk *C); |
| Symbol *addImportData(StringRef N, ImportFile *F); |
| Symbol *addImportThunk(StringRef Name, DefinedImportData *S, |
| uint16_t Machine); |
| |
| void reportDuplicate(Symbol *Existing, InputFile *NewFile); |
| |
| // A list of chunks which to be added to .rdata. |
| std::vector<Chunk *> LocalImportChunks; |
| |
| private: |
| void readArchive(); |
| void readObjects(); |
| |
| std::pair<Symbol *, bool> insert(StringRef Name); |
| StringRef findByPrefix(StringRef Prefix); |
| |
| void addCombinedLTOObject(ObjectFile *Obj); |
| std::vector<ObjectFile *> createLTOObjects(llvm::LTOCodeGenerator *CG); |
| |
| llvm::DenseMap<llvm::CachedHashStringRef, Symbol *> Symtab; |
| |
| std::vector<BitcodeFile *> BitcodeFiles; |
| std::vector<SmallString<0>> Objs; |
| }; |
| |
| extern SymbolTable *Symtab; |
| |
| } // namespace coff |
| } // namespace lld |
| |
| #endif |