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//===- lib/ReaderWriter/ELF/ELFLinkingContext.cpp -------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lld/ReaderWriter/ELFLinkingContext.h"
#include "TargetHandler.h"
#include "Targets.h"
#include "lld/Core/Instrumentation.h"
#include "lld/Passes/LayoutPass.h"
#include "lld/ReaderWriter/ReaderLinkerScript.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
namespace lld {
ELFLinkingContext::ELFLinkingContext(
llvm::Triple triple, std::unique_ptr<TargetHandlerBase> targetHandler)
: _outputFileType(elf::ET_EXEC), _triple(triple),
_targetHandler(std::move(targetHandler)), _baseAddress(0),
_isStaticExecutable(false), _outputYAML(false), _noInhibitExec(false),
_mergeCommonStrings(false), _runLayoutPass(true),
_useShlibUndefines(false), _dynamicLinkerArg(false),
_outputMagic(OutputMagic::DEFAULT) {}
bool ELFLinkingContext::is64Bits() const { return getTriple().isArch64Bit(); }
bool ELFLinkingContext::isLittleEndian() const {
// TODO: Do this properly. It is not defined purely by arch.
return true;
}
void ELFLinkingContext::addPasses(PassManager &pm) const {
if (_runLayoutPass)
pm.add(std::unique_ptr<Pass>(new LayoutPass()));
}
uint16_t ELFLinkingContext::getOutputMachine() const {
switch (getTriple().getArch()) {
case llvm::Triple::x86:
return llvm::ELF::EM_386;
case llvm::Triple::x86_64:
return llvm::ELF::EM_X86_64;
case llvm::Triple::hexagon:
return llvm::ELF::EM_HEXAGON;
case llvm::Triple::ppc:
return llvm::ELF::EM_PPC;
default:
llvm_unreachable("Unhandled arch");
}
}
bool ELFLinkingContext::validateImpl(raw_ostream &diagnostics) {
if (_outputFileType == elf::ET_EXEC && _entrySymbolName.empty()) {
_entrySymbolName = "_start";
}
if (_inputFiles.empty()) {
diagnostics << "No input files\n";
return true;
}
_elfReader = createReaderELF(*this);
_linkerScriptReader.reset(new ReaderLinkerScript(*this));
_writer = _outputYAML ? createWriterYAML(*this) : createWriterELF(*this);
return false;
}
bool ELFLinkingContext::isDynamic() const {
switch (_outputFileType) {
case llvm::ELF::ET_EXEC:
return !_isStaticExecutable;
case llvm::ELF::ET_DYN:
return true;
}
return false;
}
bool ELFLinkingContext::isRelativeReloc(const Reference &) const {
return false;
}
error_code ELFLinkingContext::parseFile(
std::unique_ptr<MemoryBuffer> &mb,
std::vector<std::unique_ptr<File>> &result) const {
ScopedTask task(getDefaultDomain(), "parseFile");
error_code ec = _elfReader->parseFile(mb, result);
if (!ec)
return ec;
// Not an ELF file, check file extension to see if it might be yaml
StringRef path = mb->getBufferIdentifier();
if (path.endswith(".objtxt")) {
ec = _yamlReader->parseFile(mb, result);
if (!ec)
return ec;
}
// Not a yaml file, assume it is a linkerscript
return _linkerScriptReader->parseFile(mb, result);
}
Writer &ELFLinkingContext::writer() const { return *_writer; }
std::unique_ptr<ELFLinkingContext>
ELFLinkingContext::create(llvm::Triple triple) {
switch (triple.getArch()) {
case llvm::Triple::x86:
return std::unique_ptr<ELFLinkingContext>(
new lld::elf::X86LinkingContext(triple));
case llvm::Triple::x86_64:
return std::unique_ptr<ELFLinkingContext>(
new lld::elf::X86_64LinkingContext(triple));
case llvm::Triple::hexagon:
return std::unique_ptr<ELFLinkingContext>(
new lld::elf::HexagonLinkingContext(triple));
case llvm::Triple::ppc:
return std::unique_ptr<ELFLinkingContext>(
new lld::elf::PPCLinkingContext(triple));
default:
return nullptr;
}
}
bool ELFLinkingContext::appendLibrary(StringRef libName) {
bool foundFile = false;
StringRef pathref;
for (StringRef dir : _inputSearchPaths) {
// Search for dynamic library
if (!_isStaticExecutable) {
SmallString<128> dynlibPath;
dynlibPath.assign(dir);
llvm::sys::path::append(dynlibPath, Twine("lib") + libName + ".so");
pathref = dynlibPath.str();
if (llvm::sys::fs::exists(pathref)) {
foundFile = true;
}
}
// Search for static libraries too
if (!foundFile) {
SmallString<128> archivefullPath;
archivefullPath.assign(dir);
llvm::sys::path::append(archivefullPath, Twine("lib") + libName + ".a");
pathref = archivefullPath.str();
if (llvm::sys::fs::exists(pathref)) {
foundFile = true;
}
}
if (foundFile) {
unsigned pathlen = pathref.size();
char *x = _extraStrings.Allocate<char>(pathlen);
memcpy(x, pathref.data(), pathlen);
appendInputFile(StringRef(x, pathlen));
return false;
}
}
return true;
}
} // end namespace lld
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