hanchenye-llvm-project/lld/lib/ReaderWriter/ELF/X86_64/X86_64LinkingContext.cpp

116 lines
3.2 KiB
C++

//===- lib/ReaderWriter/ELF/X86_64/X86_64LinkingContext.cpp ---------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "X86_64LinkingContext.h"
#include "lld/Core/File.h"
#include "lld/Core/Instrumentation.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringSwitch.h"
#include "Atoms.h"
#include "X86_64RelocationPass.h"
using namespace lld;
using namespace lld::elf;
using llvm::makeArrayRef;
namespace {
using namespace llvm::ELF;
const uint8_t x86_64InitFiniAtomContent[8] = { 0 };
// X86_64InitFini Atom
class X86_64InitAtom : public InitFiniAtom {
public:
X86_64InitAtom(const File &f, StringRef function)
: InitFiniAtom(f, ".init_array") {
#ifndef NDEBUG
_name = "__init_fn_";
_name += function;
#endif
}
virtual ArrayRef<uint8_t> rawContent() const {
return makeArrayRef(x86_64InitFiniAtomContent);
}
virtual Alignment alignment() const { return Alignment(3); }
};
class X86_64FiniAtom : public InitFiniAtom {
public:
X86_64FiniAtom(const File &f, StringRef function)
: InitFiniAtom(f, ".fini_array") {
#ifndef NDEBUG
_name = "__fini_fn_";
_name += function;
#endif
}
virtual ArrayRef<uint8_t> rawContent() const {
return makeArrayRef(x86_64InitFiniAtomContent);
}
virtual Alignment alignment() const { return Alignment(3); }
};
class X86_64InitFiniFile : public SimpleFile {
public:
X86_64InitFiniFile(const ELFLinkingContext &context)
: SimpleFile("command line option -init/-fini"), _ordinal(0) {}
void addInitFunction(StringRef name) {
Atom *initFunctionAtom = new (_allocator) SimpleUndefinedAtom(*this, name);
X86_64InitAtom *initAtom =
(new (_allocator) X86_64InitAtom(*this, name));
initAtom->addReferenceELF_x86_64(llvm::ELF::R_X86_64_64, 0,
initFunctionAtom, 0);
initAtom->setOrdinal(_ordinal++);
addAtom(*initFunctionAtom);
addAtom(*initAtom);
}
void addFiniFunction(StringRef name) {
Atom *finiFunctionAtom = new (_allocator) SimpleUndefinedAtom(*this, name);
X86_64FiniAtom *finiAtom =
(new (_allocator) X86_64FiniAtom(*this, name));
finiAtom->addReferenceELF_x86_64(llvm::ELF::R_X86_64_64, 0,
finiFunctionAtom, 0);
finiAtom->setOrdinal(_ordinal++);
addAtom(*finiFunctionAtom);
addAtom(*finiAtom);
}
private:
llvm::BumpPtrAllocator _allocator;
uint64_t _ordinal;
};
} // end anon namespace
void elf::X86_64LinkingContext::addPasses(PassManager &pm) {
auto pass = createX86_64RelocationPass(*this);
if (pass)
pm.add(std::move(pass));
ELFLinkingContext::addPasses(pm);
}
void elf::X86_64LinkingContext::createInternalFiles(
std::vector<std::unique_ptr<File> > &result) const {
ELFLinkingContext::createInternalFiles(result);
std::unique_ptr<X86_64InitFiniFile> initFiniFile(
new X86_64InitFiniFile(*this));
for (auto ai : initFunctions())
initFiniFile->addInitFunction(ai);
for (auto ai:finiFunctions())
initFiniFile->addFiniFunction(ai);
result.push_back(std::move(initFiniFile));
}