From 4fb5119215f897b5f3503d38e35f8529f18eb19e Mon Sep 17 00:00:00 2001 From: Rumeet Dhindsa Date: Mon, 7 May 2018 23:14:12 +0000 Subject: [PATCH] Add support for thinlto option ( thinlto-emit-imports-files) to emit import files for thinlink. Differential Revision: https://reviews.llvm.org/D46400 llvm-svn: 331696 --- lld/ELF/Config.h | 1 + lld/ELF/Driver.cpp | 2 + lld/ELF/LTO.cpp | 21 ++++++--- lld/test/ELF/lto/thinlto_emit_imports.ll | 55 ++++++++++++++++++++++++ 4 files changed, 72 insertions(+), 7 deletions(-) create mode 100644 lld/test/ELF/lto/thinlto_emit_imports.ll diff --git a/lld/ELF/Config.h b/lld/ELF/Config.h index bba29250a3ca..5df879e21c42 100644 --- a/lld/ELF/Config.h +++ b/lld/ELF/Config.h @@ -158,6 +158,7 @@ struct Configuration { bool SysvHash = false; bool Target1Rel; bool Trace; + bool ThinLTOEmitImportsFiles; bool ThinLTOIndexOnly; bool UndefinedVersion; bool WarnBackrefs; diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp index 7d9f8397bf44..d22373a5ded5 100644 --- a/lld/ELF/Driver.cpp +++ b/lld/ELF/Driver.cpp @@ -801,6 +801,8 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) { } else if (S.startswith("thinlto-index-only=")) { Config->ThinLTOIndexOnly = true; Config->ThinLTOIndexOnlyObjectsFile = S.substr(19); + } else if (S == "thinlto-emit-imports-files") { + Config->ThinLTOEmitImportsFiles = true; } else if (S.startswith("thinlto-prefix-replace=")) { std::tie(Config->ThinLTOPrefixReplace.first, Config->ThinLTOPrefixReplace.second) = S.substr(23).split(';'); diff --git a/lld/ELF/LTO.cpp b/lld/ELF/LTO.cpp index 0cce9a1ddd2b..bd963a7f3c6f 100644 --- a/lld/ELF/LTO.cpp +++ b/lld/ELF/LTO.cpp @@ -86,8 +86,7 @@ static std::unique_ptr openFile(StringRef File) { static std::string getThinLTOOutputFile(StringRef ModulePath) { return lto::getThinLTOOutputFile(ModulePath, Config->ThinLTOPrefixReplace.first, - Config->ThinLTOPrefixReplace.second) + - ".thinlto.bc"; + Config->ThinLTOPrefixReplace.second); } // Initializes IndexFile, Backend and LTOObj members. @@ -134,7 +133,7 @@ void BitcodeCompiler::init() { IndexFile = openFile(Config->ThinLTOIndexOnlyObjectsFile); Backend = lto::createWriteIndexesThinBackend( Config->ThinLTOPrefixReplace.first, Config->ThinLTOPrefixReplace.second, - true, IndexFile.get(), nullptr); + Config->ThinLTOEmitImportsFiles, IndexFile.get(), nullptr); } Conf.SampleProfile = Config->LTOSampleProfile; @@ -167,8 +166,13 @@ void BitcodeCompiler::add(BitcodeFile &F) { lto::InputFile &Obj = *F.Obj; // Create the empty files which, if indexed, will be overwritten later. - if (Config->ThinLTOIndexOnly) - openFile(getThinLTOOutputFile(Obj.getName())); + if (Config->ThinLTOIndexOnly) { + std::string Path = getThinLTOOutputFile(Obj.getName()); + openFile(Path + ".thinlto.bc"); + + if (Config->ThinLTOEmitImportsFiles) + openFile(Path + ".imports"); + } unsigned SymNum = 0; std::vector Syms = F.getSymbols(); @@ -269,14 +273,17 @@ std::vector BitcodeCompiler::compile() { if (F->AddedToLink || !isBitcode(F->MB)) continue; - std::unique_ptr OS = - openFile(getThinLTOOutputFile(F->getName())); + std::string Path = getThinLTOOutputFile(F->getName()); + std::unique_ptr OS = openFile(Path + ".thinlto.bc"); if (!OS) continue; ModuleSummaryIndex M(false); M.setSkipModuleByDistributedBackend(); WriteIndexToFile(M, *OS); + + if (Config->ThinLTOEmitImportsFiles) + openFile(Path + ".imports"); } // ThinLTO with index only option is required to generate only the index diff --git a/lld/test/ELF/lto/thinlto_emit_imports.ll b/lld/test/ELF/lto/thinlto_emit_imports.ll new file mode 100644 index 000000000000..465e0b686c97 --- /dev/null +++ b/lld/test/ELF/lto/thinlto_emit_imports.ll @@ -0,0 +1,55 @@ +; REQUIRES: x86 + +; Generate summary sections and test lld handling. +; RUN: opt -module-summary %s -o %t.o +; RUN: opt -module-summary %p/Inputs/thinlto.ll -o %t2.o + +; Include a file with an empty module summary index, to ensure that the expected +; output files are created regardless, for a distributed build system. +; RUN: opt -module-summary %p/Inputs/thinlto_empty.ll -o %t3.o + +; Ensure lld generates imports files if requested for distributed backends. +; RUN: rm -f %t3.o.imports %t3.o.thinlto.bc +; RUN: ld.lld --plugin-opt=thinlto-index-only --plugin-opt=thinlto-emit-imports-files -shared %t.o %t2.o %t3.o -o %t4 + +; The imports file for this module contains the bitcode file for +; Inputs/thinlto.ll +; RUN: cat %t.o.imports | count 1 +; RUN: cat %t.o.imports | FileCheck %s --check-prefix=IMPORTS1 +; IMPORTS1: thinlto_emit_imports.ll.tmp2.o + +; The imports file for Input/thinlto.ll is empty as it does not import anything. +; RUN: cat %t2.o.imports | count 0 + +; The imports file for Input/thinlto_empty.ll is empty but should exist. +; RUN: cat %t3.o.imports | count 0 + +; The index file should be created even for the input with an empty summary. +; RUN: ls %t3.o.thinlto.bc + +; Ensure lld generates error if unable to write to imports file. +; RUN: rm -f %t3.o.imports +; RUN: touch %t3.o.imports +; RUN: chmod 400 %t3.o.imports +; RUN: not ld.lld -m elf_x86_64 --plugin-opt=thinlto-index-only --plugin-opt=thinlto-emit-imports-files -shared %t.o %t2.o %t3.o -o %t4 2>&1 | FileCheck %s --check-prefix=ERR +; ERR: cannot open {{.*}}3.o.imports: {{P|p}}ermission denied + +; Ensure lld doesn't generate import files when thinlto-index-only is not enabled +; RUN: rm -f %t.o.imports +; RUN: rm -f %t2.o.imports +; RUN: rm -f %t3.o.imports +; RUN: ld.lld -m elf_x86_64 --plugin-opt=thinlto-emit-imports-files -shared %t.o %t2.o %t3.o -o %t4 +; RUN: not ls %t.o.imports +; RUN: not ls %t2.o.imports +; RUN: not ls %t4.o.imports + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +declare void @g(...) + +define void @f() { +entry: + call void (...) @g() + ret void +}