llvm-project/lld/ELF/Writer.h

74 lines
2.0 KiB
C++

//===- Writer.h -----------------------------------------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLD_ELF_WRITER_H
#define LLD_ELF_WRITER_H
#include "SymbolTable.h"
#include "llvm/Support/FileOutputBuffer.h"
namespace lld {
namespace elf2 {
// OutputSection represents a section in an output file. It's a
// container of chunks. OutputSection and Chunk are 1:N relationship.
// Chunks cannot belong to more than one OutputSections. The writer
// creates multiple OutputSections and assign them unique,
// non-overlapping file offsets and VAs.
class OutputSection {
public:
OutputSection(StringRef Name) : Name(Name), Header({}) {}
void setVA(uint64_t);
void setFileOffset(uint64_t);
template <class ELFT> void addChunk(Chunk *C);
std::vector<Chunk *> &getChunks() { return Chunks; }
template <class ELFT>
void writeHeaderTo(llvm::object::Elf_Shdr_Impl<ELFT> *SHdr);
// Returns the size of the section in the output file.
uint64_t getSize() { return Header.sh_size; }
private:
StringRef Name;
llvm::ELF::Elf64_Shdr Header;
std::vector<Chunk *> Chunks;
};
// The writer writes a SymbolTable result to a file.
template <class ELFT> class Writer {
public:
typedef typename llvm::object::ELFFile<ELFT>::uintX_t uintX_t;
explicit Writer(SymbolTable<ELFT> *T);
~Writer();
void write(StringRef Path);
private:
void createSections();
void assignAddresses();
void openFile(StringRef OutputPath);
void writeHeader();
void writeSections();
SymbolTable<ELFT> *Symtab;
std::unique_ptr<llvm::FileOutputBuffer> Buffer;
llvm::SpecificBumpPtrAllocator<OutputSection> CAlloc;
std::vector<OutputSection *> OutputSections;
uint64_t FileSize;
uint64_t SizeOfHeaders;
uintX_t SectionHeaderOff;
std::vector<std::unique_ptr<Chunk>> Chunks;
};
} // namespace elf2
} // namespace lld
#endif