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//===- InputFiles.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_INPUT_FILES_H
#define LLD_COFF_INPUT_FILES_H
#include "lld/Core/LLVM.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/LTO/LTOModule.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/COFF.h"
#include "llvm/Support/StringSaver.h"
#include <memory>
#include <mutex>
#include <set>
#include <vector>
namespace lld {
namespace coff {
using llvm::LTOModule;
using llvm::COFF::IMAGE_FILE_MACHINE_UNKNOWN;
using llvm::COFF::MachineTypes;
using llvm::object::Archive;
using llvm::object::COFFObjectFile;
using llvm::object::COFFSymbolRef;
using llvm::object::coff_section;
class Chunk;
class Defined;
class DefinedImportData;
class DefinedImportThunk;
class Lazy;
class SymbolBody;
class Undefined;
// The root class of input files.
class InputFile {
public:
enum Kind { ArchiveKind, ObjectKind, ImportKind, BitcodeKind };
Kind kind() const { return FileKind; }
virtual ~InputFile() {}
// Returns the filename.
StringRef getName() { return MB.getBufferIdentifier(); }
// Returns symbols defined by this file.
virtual std::vector<SymbolBody *> &getSymbols() = 0;
// Reads a file (the constructor doesn't do that).
virtual void parse() = 0;
// Returns the CPU type this file was compiled to.
virtual MachineTypes getMachineType() { return IMAGE_FILE_MACHINE_UNKNOWN; }
// Returns a short, human-friendly filename. If this is a member of
// an archive file, a returned value includes parent's filename.
// Used for logging or debugging.
std::string getShortName();
// Sets a parent filename if this file is created from an archive.
void setParentName(StringRef N) { ParentName = N; }
// Returns .drectve section contents if exist.
StringRef getDirectives() { return StringRef(Directives).trim(); }
// Each file has a unique index. The index number is used to
// resolve ties in symbol resolution.
int Index;
static int NextIndex;
protected:
InputFile(Kind K, MemoryBufferRef M)
: Index(NextIndex++), MB(M), FileKind(K) {}
MemoryBufferRef MB;
std::string Directives;
private:
const Kind FileKind;
StringRef ParentName;
};
// .lib or .a file.
class ArchiveFile : public InputFile {
public:
explicit ArchiveFile(MemoryBufferRef M) : InputFile(ArchiveKind, M) {}
static bool classof(const InputFile *F) { return F->kind() == ArchiveKind; }
void parse() override;
// Returns a memory buffer for a given symbol. An empty memory buffer
// is returned if we have already returned the same memory buffer.
// (So that we don't instantiate same members more than once.)
MemoryBufferRef getMember(const Archive::Symbol *Sym);
llvm::MutableArrayRef<Lazy> getLazySymbols() { return LazySymbols; }
// All symbols returned by ArchiveFiles are of Lazy type.
std::vector<SymbolBody *> &getSymbols() override {
llvm_unreachable("internal error");
}
private:
std::unique_ptr<Archive> File;
std::string Filename;
std::vector<Lazy> LazySymbols;
std::map<uint64_t, std::atomic_flag> Seen;
};
// .obj or .o file. This may be a member of an archive file.
class ObjectFile : public InputFile {
public:
explicit ObjectFile(MemoryBufferRef M) : InputFile(ObjectKind, M) {}
static bool classof(const InputFile *F) { return F->kind() == ObjectKind; }
void parse() override;
MachineTypes getMachineType() override;
std::vector<Chunk *> &getChunks() { return Chunks; }
std::vector<SymbolBody *> &getSymbols() override { return SymbolBodies; }
// Returns a SymbolBody object for the SymbolIndex'th symbol in the
// underlying object file.
SymbolBody *getSymbolBody(uint32_t SymbolIndex) {
return SparseSymbolBodies[SymbolIndex];
}
// Returns the underying COFF file.
COFFObjectFile *getCOFFObj() { return COFFObj.get(); }
// True if this object file is compatible with SEH.
// COFF-specific and x86-only.
bool SEHCompat = false;
// The list of safe exception handlers listed in .sxdata section.
// COFF-specific and x86-only.
std::set<SymbolBody *> SEHandlers;
private:
void initializeChunks();
void initializeSymbols();
void initializeSEH();
Defined *createDefined(COFFSymbolRef Sym, const void *Aux, bool IsFirst);
Undefined *createUndefined(COFFSymbolRef Sym);
std::unique_ptr<COFFObjectFile> COFFObj;
llvm::BumpPtrAllocator Alloc;
const coff_section *SXData = nullptr;
// List of all chunks defined by this file. This includes both section
// chunks and non-section chunks for common symbols.
std::vector<Chunk *> Chunks;
// This vector contains the same chunks as Chunks, but they are
// indexed such that you can get a SectionChunk by section index.
// Nonexistent section indices are filled with null pointers.
// (Because section number is 1-based, the first slot is always a
// null pointer.)
std::vector<Chunk *> SparseChunks;
// List of all symbols referenced or defined by this file.
std::vector<SymbolBody *> SymbolBodies;
// This vector contains the same symbols as SymbolBodies, but they
// are indexed such that you can get a SymbolBody by symbol
// index. Nonexistent indices (which are occupied by auxiliary
// symbols in the real symbol table) are filled with null pointers.
std::vector<SymbolBody *> SparseSymbolBodies;
};
// This type represents import library members that contain DLL names
// and symbols exported from the DLLs. See Microsoft PE/COFF spec. 7
// for details about the format.
class ImportFile : public InputFile {
public:
explicit ImportFile(MemoryBufferRef M)
: InputFile(ImportKind, M), StringAlloc(StringAllocAux) {}
static bool classof(const InputFile *F) { return F->kind() == ImportKind; }
std::vector<SymbolBody *> &getSymbols() override { return SymbolBodies; }
DefinedImportData *ImpSym = nullptr;
DefinedImportThunk *ThunkSym = nullptr;
std::string DLLName;
private:
void parse() override;
std::vector<SymbolBody *> SymbolBodies;
llvm::BumpPtrAllocator Alloc;
llvm::BumpPtrAllocator StringAllocAux;
llvm::StringSaver StringAlloc;
};
// Used for LTO.
class BitcodeFile : public InputFile {
public:
explicit BitcodeFile(MemoryBufferRef M) : InputFile(BitcodeKind, M) {}
static bool classof(const InputFile *F) { return F->kind() == BitcodeKind; }
std::vector<SymbolBody *> &getSymbols() override { return SymbolBodies; }
MachineTypes getMachineType() override;
std::unique_ptr<LTOModule> takeModule() { return std::move(M); }
private:
void parse() override;
std::vector<SymbolBody *> SymbolBodies;
llvm::BumpPtrAllocator Alloc;
std::unique_ptr<LTOModule> M;
static std::mutex Mu;
};
} // namespace coff
} // namespace lld
#endif