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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_ELF_INPUT_FILES_H
#define LLD_ELF_INPUT_FILES_H
#include "Config.h"
#include "InputSection.h"
#include "Error.h"
#include "Symbols.h"
#include "lld/Core/LLVM.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/IR/Comdat.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/ELF.h"
#include "llvm/Object/IRObjectFile.h"
#include "llvm/Support/StringSaver.h"
namespace lld {
namespace elf {
using llvm::object::Archive;
class InputFile;
class Lazy;
class SymbolBody;
// The root class of input files.
class InputFile {
public:
enum Kind { ObjectKind, SharedKind, ArchiveKind, BitcodeKind };
Kind kind() const { return FileKind; }
StringRef getName() const { return MB.getBufferIdentifier(); }
MemoryBufferRef MB;
// Filename of .a which contained this file. If this file was
// not in an archive file, it is the empty string. We use this
// string for creating error messages.
StringRef ArchiveName;
protected:
InputFile(Kind K, MemoryBufferRef M) : MB(M), FileKind(K) {}
private:
const Kind FileKind;
};
template <typename ELFT> class ELFFileBase : public InputFile {
public:
typedef typename ELFT::Shdr Elf_Shdr;
typedef typename ELFT::Sym Elf_Sym;
typedef typename ELFT::Word Elf_Word;
typedef typename ELFT::SymRange Elf_Sym_Range;
ELFFileBase(Kind K, MemoryBufferRef M);
static bool classof(const InputFile *F) {
Kind K = F->kind();
return K == ObjectKind || K == SharedKind;
}
static ELFKind getELFKind();
const llvm::object::ELFFile<ELFT> &getObj() const { return ELFObj; }
llvm::object::ELFFile<ELFT> &getObj() { return ELFObj; }
uint16_t getEMachine() const { return getObj().getHeader()->e_machine; }
uint8_t getOSABI() const {
return getObj().getHeader()->e_ident[llvm::ELF::EI_OSABI];
}
StringRef getStringTable() const { return StringTable; }
uint32_t getSectionIndex(const Elf_Sym &Sym) const;
protected:
llvm::object::ELFFile<ELFT> ELFObj;
const Elf_Shdr *Symtab = nullptr;
ArrayRef<Elf_Word> SymtabSHNDX;
StringRef StringTable;
void initStringTable();
Elf_Sym_Range getElfSymbols(bool OnlyGlobals);
};
// .o file.
template <class ELFT> class ObjectFile : public ELFFileBase<ELFT> {
typedef ELFFileBase<ELFT> Base;
typedef typename ELFT::Sym Elf_Sym;
typedef typename ELFT::Shdr Elf_Shdr;
typedef typename ELFT::SymRange Elf_Sym_Range;
typedef typename ELFT::Word Elf_Word;
typedef typename ELFT::uint uintX_t;
StringRef getShtGroupSignature(const Elf_Shdr &Sec);
ArrayRef<Elf_Word> getShtGroupEntries(const Elf_Shdr &Sec);
public:
static bool classof(const InputFile *F) {
return F->kind() == Base::ObjectKind;
}
ArrayRef<SymbolBody *> getSymbols();
ArrayRef<SymbolBody *> getLocalSymbols();
ArrayRef<SymbolBody *> getNonLocalSymbols();
explicit ObjectFile(MemoryBufferRef M);
void parse(llvm::DenseSet<StringRef> &ComdatGroups);
ArrayRef<InputSectionBase<ELFT> *> getSections() const { return Sections; }
InputSectionBase<ELFT> *getSection(const Elf_Sym &Sym) const;
SymbolBody &getSymbolBody(uint32_t SymbolIndex) const {
return *SymbolBodies[SymbolIndex];
}
const Elf_Shdr *getSymbolTable() const { return this->Symtab; };
// Get MIPS GP0 value defined by this file. This value represents the gp value
// used to create the relocatable object and required to support
// R_MIPS_GPREL16 / R_MIPS_GPREL32 relocations.
uint32_t getMipsGp0() const;
// The number is the offset in the string table. It will be used as the
// st_name of the symbol.
std::vector<std::pair<const Elf_Sym *, unsigned>> KeptLocalSyms;
private:
void initializeSections(llvm::DenseSet<StringRef> &ComdatGroups);
void initializeSymbols();
InputSectionBase<ELFT> *getRelocTarget(const Elf_Shdr &Sec);
InputSectionBase<ELFT> *createInputSection(const Elf_Shdr &Sec);
SymbolBody *createSymbolBody(const Elf_Sym *Sym);
// List of all sections defined by this file.
std::vector<InputSectionBase<ELFT> *> Sections;
// List of all symbols referenced or defined by this file.
std::vector<SymbolBody *> SymbolBodies;
// MIPS .reginfo section defined by this file.
MipsReginfoInputSection<ELFT> *MipsReginfo = nullptr;
llvm::BumpPtrAllocator Alloc;
llvm::SpecificBumpPtrAllocator<MergeInputSection<ELFT>> MAlloc;
llvm::SpecificBumpPtrAllocator<EHInputSection<ELFT>> EHAlloc;
};
class ArchiveFile : public InputFile {
public:
explicit ArchiveFile(MemoryBufferRef M) : InputFile(ArchiveKind, M) {}
static bool classof(const InputFile *F) { return F->kind() == ArchiveKind; }
void parse();
// 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; }
private:
std::unique_ptr<Archive> File;
std::vector<Lazy> LazySymbols;
llvm::DenseSet<uint64_t> Seen;
};
class BitcodeFile : public InputFile {
public:
explicit BitcodeFile(MemoryBufferRef M);
static bool classof(const InputFile *F);
void parse(llvm::DenseSet<StringRef> &ComdatGroups);
ArrayRef<SymbolBody *> getSymbols() { return SymbolBodies; }
static bool shouldSkip(const llvm::object::BasicSymbolRef &Sym);
private:
std::vector<SymbolBody *> SymbolBodies;
llvm::BumpPtrAllocator Alloc;
llvm::StringSaver Saver{Alloc};
SymbolBody *
createSymbolBody(const llvm::DenseSet<const llvm::Comdat *> &KeptComdats,
const llvm::object::IRObjectFile &Obj,
const llvm::object::BasicSymbolRef &Sym);
};
// .so file.
template <class ELFT> class SharedFile : public ELFFileBase<ELFT> {
typedef ELFFileBase<ELFT> Base;
typedef typename ELFT::Shdr Elf_Shdr;
typedef typename ELFT::Sym Elf_Sym;
typedef typename ELFT::Word Elf_Word;
typedef typename ELFT::SymRange Elf_Sym_Range;
std::vector<SharedSymbol<ELFT>> SymbolBodies;
std::vector<StringRef> Undefs;
StringRef SoName;
public:
StringRef getSoName() const { return SoName; }
llvm::MutableArrayRef<SharedSymbol<ELFT>> getSharedSymbols() {
return SymbolBodies;
}
const Elf_Shdr *getSection(const Elf_Sym &Sym) const;
llvm::ArrayRef<StringRef> getUndefinedSymbols() { return Undefs; }
static bool classof(const InputFile *F) {
return F->kind() == Base::SharedKind;
}
explicit SharedFile(MemoryBufferRef M);
void parseSoName();
void parseRest();
// Used for --as-needed
bool AsNeeded = false;
bool IsUsed = false;
bool isNeeded() const { return !AsNeeded || IsUsed; }
};
std::unique_ptr<InputFile> createObjectFile(MemoryBufferRef MB,
StringRef ArchiveName = "");
std::unique_ptr<InputFile> createSharedFile(MemoryBufferRef MB);
} // namespace elf
} // namespace lld
#endif