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-rw-r--r--COFF/LTO.cpp188
1 files changed, 121 insertions, 67 deletions
diff --git a/COFF/LTO.cpp b/COFF/LTO.cpp
index 92d9ff0937c0..eb3c60d66077 100644
--- a/COFF/LTO.cpp
+++ b/COFF/LTO.cpp
@@ -1,9 +1,8 @@
//===- LTO.cpp ------------------------------------------------------------===//
//
-// The LLVM Linker
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
@@ -11,6 +10,7 @@
#include "Config.h"
#include "InputFiles.h"
#include "Symbols.h"
+#include "lld/Common/Args.h"
#include "lld/Common/ErrorHandler.h"
#include "lld/Common/Strings.h"
#include "lld/Common/TargetOptionsCommandFlags.h"
@@ -18,6 +18,7 @@
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
#include "llvm/IR/DiagnosticPrinter.h"
#include "llvm/LTO/Caching.h"
#include "llvm/LTO/Config.h"
@@ -41,112 +42,165 @@ using namespace llvm::object;
using namespace lld;
using namespace lld::coff;
-static std::unique_ptr<lto::LTO> createLTO() {
- lto::Config C;
- C.Options = InitTargetOptionsFromCodeGenFlags();
+// Creates an empty file to and returns a raw_fd_ostream to write to it.
+static std::unique_ptr<raw_fd_ostream> openFile(StringRef file) {
+ std::error_code ec;
+ auto ret =
+ llvm::make_unique<raw_fd_ostream>(file, ec, sys::fs::OpenFlags::F_None);
+ if (ec) {
+ error("cannot open " + file + ": " + ec.message());
+ return nullptr;
+ }
+ return ret;
+}
+
+static std::string getThinLTOOutputFile(StringRef path) {
+ return lto::getThinLTOOutputFile(path,
+ config->thinLTOPrefixReplace.first,
+ config->thinLTOPrefixReplace.second);
+}
+
+static lto::Config createConfig() {
+ lto::Config c;
+ c.Options = initTargetOptionsFromCodeGenFlags();
// Always emit a section per function/datum with LTO. LLVM LTO should get most
// of the benefit of linker GC, but there are still opportunities for ICF.
- C.Options.FunctionSections = true;
- C.Options.DataSections = true;
+ c.Options.FunctionSections = true;
+ c.Options.DataSections = true;
// Use static reloc model on 32-bit x86 because it usually results in more
// compact code, and because there are also known code generation bugs when
// using the PIC model (see PR34306).
- if (Config->Machine == COFF::IMAGE_FILE_MACHINE_I386)
- C.RelocModel = Reloc::Static;
+ if (config->machine == COFF::IMAGE_FILE_MACHINE_I386)
+ c.RelocModel = Reloc::Static;
else
- C.RelocModel = Reloc::PIC_;
- C.DisableVerify = true;
- C.DiagHandler = diagnosticHandler;
- C.OptLevel = Config->LTOO;
- C.CPU = GetCPUStr();
- C.MAttrs = GetMAttrs();
-
- if (Config->SaveTemps)
- checkError(C.addSaveTemps(std::string(Config->OutputFile) + ".",
+ c.RelocModel = Reloc::PIC_;
+ c.DisableVerify = true;
+ c.DiagHandler = diagnosticHandler;
+ c.OptLevel = config->ltoo;
+ c.CPU = getCPUStr();
+ c.MAttrs = getMAttrs();
+ c.CGOptLevel = args::getCGOptLevel(config->ltoo);
+
+ if (config->saveTemps)
+ checkError(c.addSaveTemps(std::string(config->outputFile) + ".",
/*UseInputModulePath*/ true));
- lto::ThinBackend Backend;
- if (Config->ThinLTOJobs != 0)
- Backend = lto::createInProcessThinBackend(Config->ThinLTOJobs);
- return llvm::make_unique<lto::LTO>(std::move(C), Backend,
- Config->LTOPartitions);
+ return c;
}
-BitcodeCompiler::BitcodeCompiler() : LTOObj(createLTO()) {}
+BitcodeCompiler::BitcodeCompiler() {
+ // Initialize indexFile.
+ if (!config->thinLTOIndexOnlyArg.empty())
+ indexFile = openFile(config->thinLTOIndexOnlyArg);
+
+ // Initialize ltoObj.
+ lto::ThinBackend backend;
+ if (config->thinLTOIndexOnly) {
+ auto OnIndexWrite = [&](StringRef S) { thinIndices.erase(S); };
+ backend = lto::createWriteIndexesThinBackend(
+ config->thinLTOPrefixReplace.first, config->thinLTOPrefixReplace.second,
+ config->thinLTOEmitImportsFiles, indexFile.get(), OnIndexWrite);
+ } else if (config->thinLTOJobs != 0) {
+ backend = lto::createInProcessThinBackend(config->thinLTOJobs);
+ }
+
+ ltoObj = llvm::make_unique<lto::LTO>(createConfig(), backend,
+ config->ltoPartitions);
+}
BitcodeCompiler::~BitcodeCompiler() = default;
-static void undefine(Symbol *S) { replaceSymbol<Undefined>(S, S->getName()); }
+static void undefine(Symbol *s) { replaceSymbol<Undefined>(s, s->getName()); }
+
+void BitcodeCompiler::add(BitcodeFile &f) {
+ lto::InputFile &obj = *f.obj;
+ unsigned symNum = 0;
+ std::vector<Symbol *> symBodies = f.getSymbols();
+ std::vector<lto::SymbolResolution> resols(symBodies.size());
-void BitcodeCompiler::add(BitcodeFile &F) {
- lto::InputFile &Obj = *F.Obj;
- unsigned SymNum = 0;
- std::vector<Symbol *> SymBodies = F.getSymbols();
- std::vector<lto::SymbolResolution> Resols(SymBodies.size());
+ if (config->thinLTOIndexOnly)
+ thinIndices.insert(obj.getName());
// Provide a resolution to the LTO API for each symbol.
- for (const lto::InputFile::Symbol &ObjSym : Obj.symbols()) {
- Symbol *Sym = SymBodies[SymNum];
- lto::SymbolResolution &R = Resols[SymNum];
- ++SymNum;
+ for (const lto::InputFile::Symbol &objSym : obj.symbols()) {
+ Symbol *sym = symBodies[symNum];
+ 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() && Sym->getFile() == &F;
- R.VisibleToRegularObj = Sym->IsUsedInRegularObj;
- if (R.Prevailing)
- undefine(Sym);
+ r.Prevailing = !objSym.isUndefined() && sym->getFile() == &f;
+ r.VisibleToRegularObj = sym->isUsedInRegularObj;
+ if (r.Prevailing)
+ undefine(sym);
}
- checkError(LTOObj->add(std::move(F.Obj), Resols));
+ 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();
- Buf.resize(MaxTasks);
- Files.resize(MaxTasks);
+ unsigned maxTasks = ltoObj->getMaxTasks();
+ buf.resize(maxTasks);
+ files.resize(maxTasks);
// The /lldltocache option specifies the path to a directory in which to cache
// native object files for ThinLTO incremental builds. If a path was
// specified, configure LTO to use it as the cache directory.
- lto::NativeObjectCache Cache;
- if (!Config->LTOCache.empty())
- Cache = check(lto::localCache(
- Config->LTOCache, [&](size_t Task, std::unique_ptr<MemoryBuffer> MB) {
- Files[Task] = std::move(MB);
+ lto::NativeObjectCache cache;
+ if (!config->ltoCache.empty())
+ cache = check(lto::localCache(
+ config->ltoCache, [&](size_t task, std::unique_ptr<MemoryBuffer> mb) {
+ files[task] = std::move(mb);
}));
- checkError(LTOObj->run(
- [&](size_t Task) {
+ checkError(ltoObj->run(
+ [&](size_t task) {
return llvm::make_unique<lto::NativeObjectStream>(
- llvm::make_unique<raw_svector_ostream>(Buf[Task]));
+ llvm::make_unique<raw_svector_ostream>(buf[task]));
},
- Cache));
+ cache));
+
+ // Emit empty index files for non-indexed files
+ for (StringRef s : thinIndices) {
+ std::string path = getThinLTOOutputFile(s);
+ openFile(path + ".thinlto.bc");
+ if (config->thinLTOEmitImportsFiles)
+ openFile(path + ".imports");
+ }
+
+ // ThinLTO with index only option is required to generate only the index
+ // files. After that, we exit from linker and ThinLTO backend runs in a
+ // distributed environment.
+ if (config->thinLTOIndexOnly) {
+ if (indexFile)
+ indexFile->close();
+ return {};
+ }
- if (!Config->LTOCache.empty())
- pruneCache(Config->LTOCache, Config->LTOCachePolicy);
+ if (!config->ltoCache.empty())
+ pruneCache(config->ltoCache, config->ltoCachePolicy);
- std::vector<StringRef> Ret;
- for (unsigned I = 0; I != MaxTasks; ++I) {
- if (Buf[I].empty())
+ std::vector<StringRef> ret;
+ for (unsigned i = 0; i != maxTasks; ++i) {
+ if (buf[i].empty())
continue;
- if (Config->SaveTemps) {
- if (I == 0)
- saveBuffer(Buf[I], Config->OutputFile + ".lto.obj");
+ if (config->saveTemps) {
+ if (i == 0)
+ saveBuffer(buf[i], config->outputFile + ".lto.obj");
else
- saveBuffer(Buf[I], Config->OutputFile + Twine(I) + ".lto.obj");
+ saveBuffer(buf[i], config->outputFile + Twine(i) + ".lto.obj");
}
- Ret.emplace_back(Buf[I].data(), Buf[I].size());
+ ret.emplace_back(buf[i].data(), buf[i].size());
}
- for (std::unique_ptr<MemoryBuffer> &File : Files)
- if (File)
- Ret.push_back(File->getBuffer());
+ for (std::unique_ptr<MemoryBuffer> &file : files)
+ if (file)
+ ret.push_back(file->getBuffer());
- return Ret;
+ return ret;
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-08 09:38:26 +0000