llvm-project/lld/COFF/InputFiles.h

229 lines
6.8 KiB
C++

//===- 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 "Config.h"
#include "lld/Common/LLVM.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/LTO/LTO.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/COFF.h"
#include "llvm/Support/StringSaver.h"
#include <memory>
#include <set>
#include <vector>
namespace llvm {
namespace pdb {
class DbiModuleDescriptorBuilder;
}
}
namespace lld {
namespace coff {
std::vector<MemoryBufferRef> getArchiveMembers(llvm::object::Archive *File);
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_import_header;
using llvm::object::coff_section;
class Chunk;
class Defined;
class DefinedImportData;
class DefinedImportThunk;
class Lazy;
class SectionChunk;
class Symbol;
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(); }
// 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; }
MemoryBufferRef MB;
// An archive file name if this file is created from an archive.
StringRef ParentName;
// Returns .drectve section contents if exist.
StringRef getDirectives() { return StringRef(Directives).trim(); }
protected:
InputFile(Kind K, MemoryBufferRef M) : MB(M), FileKind(K) {}
std::string Directives;
private:
const Kind FileKind;
};
// .lib or .a file.
class ArchiveFile : public InputFile {
public:
explicit ArchiveFile(MemoryBufferRef M);
static bool classof(const InputFile *F) { return F->kind() == ArchiveKind; }
void parse() override;
// Enqueues an archive member load for the given symbol. If we've already
// enqueued a load for the same archive member, this function does nothing,
// which ensures that we don't load the same member more than once.
void addMember(const Archive::Symbol *Sym);
private:
std::unique_ptr<Archive> File;
std::string Filename;
llvm::DenseSet<uint64_t> Seen;
};
// .obj or .o file. This may be a member of an archive file.
class ObjFile : public InputFile {
public:
explicit ObjFile(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<SectionChunk *> &getDebugChunks() { return DebugChunks; }
std::vector<Symbol *> &getSymbols() { return SymbolBodies; }
// Returns a Symbol object for the SymbolIndex'th symbol in the
// underlying object file.
Symbol *getSymbol(uint32_t SymbolIndex) {
return SparseSymbolBodies[SymbolIndex];
}
// Returns the underying COFF file.
COFFObjectFile *getCOFFObj() { return COFFObj.get(); }
static std::vector<ObjFile *> Instances;
// 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<Symbol *> SEHandlers;
// Pointer to the PDB module descriptor builder. Various debug info records
// will reference object files by "module index", which is here. Things like
// source files and section contributions are also recorded here. Will be null
// if we are not producing a PDB.
llvm::pdb::DbiModuleDescriptorBuilder *ModuleDBI = nullptr;
private:
void initializeChunks();
void initializeSymbols();
void initializeSEH();
Symbol *createDefined(COFFSymbolRef Sym, const void *Aux, bool IsFirst);
Symbol *createUndefined(COFFSymbolRef Sym);
std::unique_ptr<COFFObjectFile> COFFObj;
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;
// CodeView debug info sections.
std::vector<SectionChunk *> DebugChunks;
// 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<Symbol *> SymbolBodies;
// This vector contains the same symbols as SymbolBodies, but they
// are indexed such that you can get a Symbol by symbol
// index. Nonexistent indices (which are occupied by auxiliary
// symbols in the real symbol table) are filled with null pointers.
std::vector<Symbol *> 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), Live(!Config->DoGC) {}
static bool classof(const InputFile *F) { return F->kind() == ImportKind; }
static std::vector<ImportFile *> Instances;
DefinedImportData *ImpSym = nullptr;
DefinedImportThunk *ThunkSym = nullptr;
std::string DLLName;
private:
void parse() override;
public:
StringRef ExternalName;
const coff_import_header *Hdr;
Chunk *Location = nullptr;
// We want to eliminate dllimported symbols if no one actually refers them.
// This "Live" bit is used to keep track of which import library members
// are actually in use.
//
// If the Live bit is turned off by MarkLive, Writer will ignore dllimported
// symbols provided by this import library member.
bool Live;
};
// 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<Symbol *> &getSymbols() { return SymbolBodies; }
MachineTypes getMachineType() override;
static std::vector<BitcodeFile *> Instances;
std::unique_ptr<llvm::lto::InputFile> Obj;
private:
void parse() override;
std::vector<Symbol *> SymbolBodies;
};
} // namespace coff
std::string toString(coff::InputFile *File);
} // namespace lld
#endif