Enable debug fission for thinLTO linked via gold-plugin
Summary: This enables debug fission on implicit ThinLTO when linked with gold. It will put the .dwo files in a directory specified by user.
Reviewers: tejohnson, pcc, dblaikie
Reviewed By: pcc
Subscribers: JDevlieghere, mehdi_amini, inglorion
Differential Revision: https://reviews.llvm.org/D44792
llvm-svn: 329988
diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
index e9ac314..e4dffbf 100644
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -136,6 +136,7 @@
AddString(Conf.AAPipeline);
AddString(Conf.OverrideTriple);
AddString(Conf.DefaultTriple);
+ AddString(Conf.DwoDir);
// Include the hash for the current module
auto ModHash = Index.getModuleHash(ModuleID);
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index 074a398..991e2f3 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -30,6 +30,10 @@
#include "llvm/Passes/PassBuilder.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Program.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/ThreadPool.h"
#include "llvm/Target/TargetMachine.h"
@@ -279,11 +283,74 @@
return !Conf.PostOptModuleHook || Conf.PostOptModuleHook(Task, Mod);
}
+void codegenWithSplitDwarf(Config &Conf, TargetMachine *TM,
+ AddStreamFn AddStream, unsigned Task, Module &Mod) {
+ SmallString<128> TempFile;
+ int FD = -1;
+ if (auto EC =
+ sys::fs::createTemporaryFile("lto-llvm-fission", "o", FD, TempFile))
+ report_fatal_error("Could not create temporary file " +
+ TempFile.str() + ": " + EC.message());
+ llvm::raw_fd_ostream OS(FD, true);
+ SmallString<1024> DwarfFile(Conf.DwoDir);
+ std::string DwoName = sys::path::filename(Mod.getModuleIdentifier()).str() +
+ "-" + std::to_string(Task) + "-";
+ size_t index = TempFile.str().rfind("lto-llvm-fission");
+ StringRef TempID = TempFile.str().substr(index + 17, 6);
+ DwoName += TempID.str() + ".dwo";
+ sys::path::append(DwarfFile, DwoName);
+ TM->Options.MCOptions.SplitDwarfFile = DwarfFile.str().str();
+
+ legacy::PassManager CodeGenPasses;
+ if (TM->addPassesToEmitFile(CodeGenPasses, OS, Conf.CGFileType))
+ report_fatal_error("Failed to setup codegen");
+ CodeGenPasses.run(Mod);
+
+ if (auto EC = llvm::sys::fs::create_directories(Conf.DwoDir))
+ report_fatal_error("Failed to create directory " +
+ Conf.DwoDir + ": " + EC.message());
+
+ SmallVector<const char*, 5> ExtractArgs, StripArgs;
+ ExtractArgs.push_back(Conf.Objcopy.c_str());
+ ExtractArgs.push_back("--extract-dwo");
+ ExtractArgs.push_back(TempFile.c_str());
+ ExtractArgs.push_back(TM->Options.MCOptions.SplitDwarfFile.c_str());
+ ExtractArgs.push_back(nullptr);
+ StripArgs.push_back(Conf.Objcopy.c_str());
+ StripArgs.push_back("--strip-dwo");
+ StripArgs.push_back(TempFile.c_str());
+ StripArgs.push_back(nullptr);
+
+ if (auto Ret = sys::ExecuteAndWait(Conf.Objcopy, ExtractArgs.data())) {
+ report_fatal_error("Failed to extract dwo from " + TempFile.str() +
+ ". Exit code " + std::to_string(Ret));
+ }
+ if (auto Ret = sys::ExecuteAndWait(Conf.Objcopy, StripArgs.data())) {
+ report_fatal_error("Failed to strip dwo from " + TempFile.str() +
+ ". Exit code " + std::to_string(Ret));
+ }
+
+ auto Stream = AddStream(Task);
+ auto Buffer = MemoryBuffer::getFile(TempFile);
+ if (auto EC = Buffer.getError())
+ report_fatal_error("Failed to load file " +
+ TempFile.str() + ": " + EC.message());
+ *Stream->OS << Buffer.get()->getBuffer();
+ if (auto EC = sys::fs::remove(TempFile))
+ report_fatal_error("Failed to delete file " +
+ TempFile.str() + ": " + EC.message());
+}
+
void codegen(Config &Conf, TargetMachine *TM, AddStreamFn AddStream,
unsigned Task, Module &Mod) {
if (Conf.PreCodeGenModuleHook && !Conf.PreCodeGenModuleHook(Task, Mod))
return;
+ if (!Conf.DwoDir.empty()) {
+ codegenWithSplitDwarf(Conf, TM, AddStream, Task, Mod);
+ return;
+ }
+
auto Stream = AddStream(Task);
legacy::PassManager CodeGenPasses;
if (TM->addPassesToEmitFile(CodeGenPasses, *Stream->OS, Conf.CGFileType))