1
1
mirror of https://github.com/rui314/mold.git synced 2024-12-29 11:24:36 +03:00
mold/writer.cc
2020-10-20 15:04:18 +09:00

43 lines
1.3 KiB
C++

#include "mold.h"
using namespace llvm;
using namespace llvm::ELF;
using llvm::object::ELF64LE;
static std::unique_ptr<FileOutputBuffer> open_output_file() {
int file_size = 100;
Expected<std::unique_ptr<FileOutputBuffer>> bufferOrErr =
FileOutputBuffer::create(config.output, file_size, 0);
if (!bufferOrErr)
error("failed to open " + config.output + ": " +
llvm::toString(bufferOrErr.takeError()));
return std::move(*bufferOrErr);
}
void write() {
std::unique_ptr<FileOutputBuffer> buffer = open_output_file();
uint8_t *buf = buffer->getBufferStart();
memset(buf, 0, sizeof(ELF64LE::Ehdr));
memcpy(buf, "\177ELF", 4);
auto *ehdr = reinterpret_cast<ELF64LE::Ehdr *>(buf);
ehdr->e_ident[EI_CLASS] = ELFCLASS64;
ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
ehdr->e_ident[EI_VERSION] = EV_CURRENT;
ehdr->e_ident[EI_OSABI] = 0;
ehdr->e_ident[EI_ABIVERSION] = 0;
ehdr->e_machine = EM_X86_64;
ehdr->e_version = EV_CURRENT;
ehdr->e_flags = 0;
ehdr->e_ehsize = sizeof(ELF64LE::Ehdr);
ehdr->e_phnum = 0;
ehdr->e_shentsize = sizeof(ELF64LE::Shdr);
ehdr->e_phoff = sizeof(ELF64LE::Ehdr);
ehdr->e_phentsize = sizeof(ELF64LE::Phdr);
if (auto e = buffer->commit())
error("failed to write to the output file: " + toString(std::move(e)));
}