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mirror of https://github.com/rui314/mold.git synced 2024-12-27 10:23:41 +03:00
mold/output_chunks.cc
2020-11-06 09:59:59 +09:00

122 lines
3.4 KiB
C++

#include "mold.h"
#include <shared_mutex>
using namespace llvm::ELF;
OutputEhdr *out::ehdr;
OutputShdr *out::shdr;
OutputPhdr *out::phdr;
InterpSection *out::interp;
GotSection *out::got;
GotSection *out::gotplt;
PltSection *out::plt;
RelPltSection *out::relplt;
ShstrtabSection *out::shstrtab;
SymtabSection *out::symtab;
StrtabSection *out::strtab;
u64 out::tls_end;
Symbol *out::__bss_start;
Symbol *out::__ehdr_start;
Symbol *out::__rela_iplt_start;
Symbol *out::__rela_iplt_end;
Symbol *out::__init_array_start;
Symbol *out::__init_array_end;
Symbol *out::__fini_array_start;
Symbol *out::__fini_array_end;
Symbol *out::__preinit_array_start;
Symbol *out::__preinit_array_end;
Symbol *out::end;
Symbol *out::_end;
Symbol *out::etext;
Symbol *out::_etext;
Symbol *out::edata;
Symbol *out::_edata;
std::vector<OutputSection *> OutputSection::instances;
void OutputEhdr::copy_to(u8 *buf) {
auto *hdr = (ELF64LE::Ehdr *)buf;
memset(hdr, 0, sizeof(*hdr));
memcpy(&hdr->e_ident, "\177ELF", 4);
hdr->e_ident[EI_CLASS] = ELFCLASS64;
hdr->e_ident[EI_DATA] = ELFDATA2LSB;
hdr->e_ident[EI_VERSION] = EV_CURRENT;
hdr->e_ident[EI_OSABI] = 0;
hdr->e_ident[EI_ABIVERSION] = 0;
hdr->e_type = ET_EXEC;
hdr->e_machine = EM_X86_64;
hdr->e_version = EV_CURRENT;
hdr->e_entry = Symbol::intern("_start")->addr;
hdr->e_phoff = out::phdr->shdr.sh_offset;
hdr->e_shoff = out::shdr->shdr.sh_offset;
hdr->e_flags = 0;
hdr->e_ehsize = sizeof(ELF64LE::Ehdr);
hdr->e_phentsize = sizeof(ELF64LE::Phdr);
hdr->e_phnum = out::phdr->shdr.sh_size / sizeof(ELF64LE::Phdr);
hdr->e_shentsize = sizeof(ELF64LE::Shdr);
hdr->e_shnum = out::shdr->entries.size();
hdr->e_shstrndx = out::shstrtab->shndx;
}
void OutputPhdr::copy_to(u8 *buf) {
for (Entry &ent : entries) {
OutputChunk *front = ent.members.front();
OutputChunk *back = ent.members.back();
ent.phdr.p_offset = front->shdr.sh_offset;
ent.phdr.p_filesz = (back->shdr.sh_type == SHT_NOBITS)
? back->shdr.sh_offset - front->shdr.sh_offset
: back->shdr.sh_offset - front->shdr.sh_offset + back->shdr.sh_size;
ent.phdr.p_vaddr = front->shdr.sh_addr;
ent.phdr.p_memsz =
back->shdr.sh_addr + back->shdr.sh_size - front->shdr.sh_addr;
}
auto *p = (ELF64LE::Phdr *)(buf + shdr.sh_offset);
for (Entry &ent : entries)
*p++ = ent.phdr;
}
static StringRef get_output_name(StringRef name) {
static StringRef common_names[] = {
".text.", ".data.rel.ro.", ".data.", ".rodata.", ".bss.rel.ro.",
".bss.", ".init_array.", ".fini_array.", ".tbss.", ".tdata.",
};
for (StringRef s : common_names)
if (name.startswith(s) || name == s.drop_back())
return s.drop_back();
return name;
}
OutputSection *
OutputSection::get_instance(StringRef name, u64 flags, u32 type) {
name = get_output_name(name);
flags = flags & ~SHF_GROUP;
auto find = [&]() -> OutputSection * {
for (OutputSection *osec : OutputSection::instances)
if (name == osec->name && flags == (osec->shdr.sh_flags & ~SHF_GROUP) &&
type == osec->shdr.sh_type)
return osec;
return nullptr;
};
// Search for an exiting output section.
static std::shared_mutex mu;
std::shared_lock shared_lock(mu);
if (OutputSection *osec = find())
return osec;
shared_lock.unlock();
// Create a new output section.
std::unique_lock unique_lock(mu);
if (OutputSection *osec = find())
return osec;
return new OutputSection(name, flags, type);
}