llvm-project/lld/ELF/InputFiles.cpp

108 lines
3.2 KiB
C++

//===- InputFiles.cpp -----------------------------------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "InputFiles.h"
#include "Chunks.h"
#include "Error.h"
#include "Symbols.h"
#include "llvm/ADT/STLExtras.h"
using namespace llvm::ELF;
using namespace lld;
using namespace lld::elf2;
template <class ELFT>
bool ObjectFile<ELFT>::isCompatibleWith(const ObjectFileBase &Other) const {
if (kind() != Other.kind())
return false;
return getObj()->getHeader()->e_machine ==
cast<ObjectFile<ELFT>>(Other).getObj()->getHeader()->e_machine;
}
template <class ELFT> void elf2::ObjectFile<ELFT>::parse() {
// Parse a memory buffer as a ELF file.
std::error_code EC;
ELFObj = llvm::make_unique<ELFFile<ELFT>>(MB.getBuffer(), EC);
error(EC);
// Read section and symbol tables.
initializeChunks();
initializeSymbols();
}
template <class ELFT> void elf2::ObjectFile<ELFT>::initializeChunks() {
uint64_t Size = ELFObj->getNumSections();
Chunks.resize(Size);
unsigned I = 0;
for (const Elf_Shdr &Sec : ELFObj->sections()) {
switch (Sec.sh_type) {
case SHT_SYMTAB:
Symtab = &Sec;
break;
case SHT_STRTAB:
case SHT_NULL:
case SHT_RELA:
case SHT_REL:
break;
default:
Chunks[I] = new (Alloc) SectionChunk<ELFT>(this->getObj(), &Sec);
break;
}
++I;
}
}
template <class ELFT> void elf2::ObjectFile<ELFT>::initializeSymbols() {
ErrorOr<StringRef> StringTableOrErr =
ELFObj->getStringTableForSymtab(*Symtab);
error(StringTableOrErr.getError());
StringRef StringTable = *StringTableOrErr;
Elf_Sym_Range Syms = ELFObj->symbols(Symtab);
uint32_t NumSymbols = std::distance(Syms.begin(), Syms.end());
uint32_t FirstNonLocal = Symtab->sh_info;
if (FirstNonLocal > NumSymbols)
error("Invalid sh_info in symbol table");
Syms = llvm::make_range(Syms.begin() + FirstNonLocal, Syms.end());
SymbolBodies.reserve(NumSymbols);
for (const Elf_Sym &Sym : Syms)
SymbolBodies.push_back(createSymbolBody(StringTable, &Sym));
}
template <class ELFT>
SymbolBody *elf2::ObjectFile<ELFT>::createSymbolBody(StringRef StringTable,
const Elf_Sym *Sym) {
ErrorOr<StringRef> NameOrErr = Sym->getName(StringTable);
error(NameOrErr.getError());
StringRef Name = *NameOrErr;
uint16_t SecIndex = Sym->st_shndx;
switch (Sym->getBinding()) {
default:
error("unexpected binding");
case STB_GLOBAL:
if (Sym->isUndefined())
return new (Alloc) Undefined<ELFT>(Name, *Sym);
return new (Alloc) DefinedRegular<ELFT>(Name, *Sym, *Chunks[SecIndex]);
case STB_WEAK:
if (Sym->isUndefined())
return new (Alloc) UndefinedWeak<ELFT>(Name, *Sym);
return new (Alloc) DefinedWeak<ELFT>(Name, *Sym, *Chunks[SecIndex]);
}
}
namespace lld {
namespace elf2 {
template class elf2::ObjectFile<llvm::object::ELF32LE>;
template class elf2::ObjectFile<llvm::object::ELF32BE>;
template class elf2::ObjectFile<llvm::object::ELF64LE>;
template class elf2::ObjectFile<llvm::object::ELF64BE>;
}
}