freebsd-dev/contrib/llvm/tools/lld/COFF/LTO.cpp
2017-04-16 16:35:48 +00:00

141 lines
4.3 KiB
C++

//===- LTO.cpp ------------------------------------------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "LTO.h"
#include "Config.h"
#include "Error.h"
#include "InputFiles.h"
#include "Symbols.h"
#include "lld/Core/TargetOptionsCommandFlags.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/IR/DiagnosticPrinter.h"
#include "llvm/LTO/Config.h"
#include "llvm/LTO/LTO.h"
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cstddef>
#include <memory>
#include <string>
#include <system_error>
#include <vector>
using namespace llvm;
using namespace llvm::object;
using namespace lld;
using namespace lld::coff;
static void diagnosticHandler(const DiagnosticInfo &DI) {
SmallString<128> ErrStorage;
raw_svector_ostream OS(ErrStorage);
DiagnosticPrinterRawOStream DP(OS);
DI.print(DP);
warn(ErrStorage);
}
static void checkError(Error E) {
handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) -> Error {
error(EIB.message());
return Error::success();
});
}
static void saveBuffer(StringRef Buffer, const Twine &Path) {
std::error_code EC;
raw_fd_ostream OS(Path.str(), EC, sys::fs::OpenFlags::F_None);
if (EC)
error("cannot create " + Path + ": " + EC.message());
OS << Buffer;
}
static std::unique_ptr<lto::LTO> createLTO() {
lto::Config Conf;
Conf.Options = InitTargetOptionsFromCodeGenFlags();
Conf.RelocModel = Reloc::PIC_;
Conf.DisableVerify = true;
Conf.DiagHandler = diagnosticHandler;
Conf.OptLevel = Config->LTOOptLevel;
if (Config->SaveTemps)
checkError(Conf.addSaveTemps(std::string(Config->OutputFile) + ".",
/*UseInputModulePath*/ true));
lto::ThinBackend Backend;
if (Config->LTOJobs != 0)
Backend = lto::createInProcessThinBackend(Config->LTOJobs);
return llvm::make_unique<lto::LTO>(std::move(Conf), Backend,
Config->LTOPartitions);
}
BitcodeCompiler::BitcodeCompiler() : LTOObj(createLTO()) {}
BitcodeCompiler::~BitcodeCompiler() = default;
static void undefine(Symbol *S) {
replaceBody<Undefined>(S, S->body()->getName());
}
void BitcodeCompiler::add(BitcodeFile &F) {
lto::InputFile &Obj = *F.Obj;
unsigned SymNum = 0;
std::vector<SymbolBody *> SymBodies = F.getSymbols();
std::vector<lto::SymbolResolution> Resols(SymBodies.size());
// Provide a resolution to the LTO API for each symbol.
for (const lto::InputFile::Symbol &ObjSym : Obj.symbols()) {
SymbolBody *B = SymBodies[SymNum];
Symbol *Sym = B->symbol();
lto::SymbolResolution &R = Resols[SymNum];
++SymNum;
// Ideally we shouldn't check for SF_Undefined but currently IRObjectFile
// reports two symbols for module ASM defined. Without this check, lld
// flags an undefined in IR with a definition in ASM as prevailing.
// Once IRObjectFile is fixed to report only one symbol this hack can
// be removed.
R.Prevailing = !ObjSym.isUndefined() && B->getFile() == &F;
R.VisibleToRegularObj = Sym->IsUsedInRegularObj;
if (R.Prevailing)
undefine(Sym);
}
checkError(LTOObj->add(std::move(F.Obj), Resols));
}
// Merge all the bitcode files we have seen, codegen the result
// and return the resulting objects.
std::vector<StringRef> BitcodeCompiler::compile() {
unsigned MaxTasks = LTOObj->getMaxTasks();
Buff.resize(MaxTasks);
checkError(LTOObj->run([&](size_t Task) {
return llvm::make_unique<lto::NativeObjectStream>(
llvm::make_unique<raw_svector_ostream>(Buff[Task]));
}));
std::vector<StringRef> Ret;
for (unsigned I = 0; I != MaxTasks; ++I) {
if (Buff[I].empty())
continue;
if (Config->SaveTemps) {
if (I == 0)
saveBuffer(Buff[I], Config->OutputFile + ".lto.obj");
else
saveBuffer(Buff[I], Config->OutputFile + Twine(I) + ".lto.obj");
}
Ret.emplace_back(Buff[I].data(), Buff[I].size());
}
return Ret;
}