[PATCH] D47597: IRGen: Write .dwo files when -split-dwarf-file is used together with -fthinlto-index.

[David Blaikie via cfe-commits]

On Thu, May 31, 2018 at 11:20 AM Peter Collingbourne via Phabricator <
reviews at reviews.llvm.org> wrote:

> pcc created this revision.
> pcc added reviewers: tejohnson, dblaikie.
> Herald added subscribers: JDevlieghere, hiraditya, eraman, inglorion,
> mehdi_amini.
>
> https://reviews.llvm.org/D47597
>
> Files:
>   clang/lib/CodeGen/BackendUtil.cpp
>   clang/test/CodeGen/thinlto-split-dwarf.c
>   llvm/include/llvm/LTO/Config.h
>   llvm/lib/LTO/LTOBackend.cpp
>
>
> Index: llvm/lib/LTO/LTOBackend.cpp
> ===================================================================
> --- llvm/lib/LTO/LTOBackend.cpp
> +++ llvm/lib/LTO/LTOBackend.cpp
> @@ -291,14 +291,19 @@
>      return;
>
>    std::unique_ptr<ToolOutputFile> DwoOut;
> +  SmallString<1024> DwoFile(Conf.DwoPath);
>    if (!Conf.DwoDir.empty()) {
>      std::error_code EC;
>      if (auto EC = llvm::sys::fs::create_directories(Conf.DwoDir))
>        report_fatal_error("Failed to create directory " + Conf.DwoDir + ":
> " +
>                           EC.message());
>
> -    SmallString<1024> DwoFile(Conf.DwoDir);
> +    DwoFile = Conf.DwoDir;
>      sys::path::append(DwoFile, std::to_string(Task) + ".dwo");
> +  }
> +
> +  if (!DwoFile.empty()) {
> +    std::error_code EC;
>      TM->Options.MCOptions.SplitDwarfFile = DwoFile.str().str();
>      DwoOut = llvm::make_unique<ToolOutputFile>(DwoFile, EC,
> sys::fs::F_None);
>      if (EC)
> Index: llvm/include/llvm/LTO/Config.h
> ===================================================================
> --- llvm/include/llvm/LTO/Config.h
> +++ llvm/include/llvm/LTO/Config.h
> @@ -76,6 +76,11 @@
>    /// The directory to store .dwo files.
>    std::string DwoDir;
>
> +  /// The path to write a .dwo file to. This should generally only be
> used when
> +  /// running an individual backend directly via thinBackend(), as
> otherwise
> +  /// all .dwo files will be written to the same path.
> +  std::string DwoPath;
> +
>    /// Optimization remarks file path.
>    std::string RemarksFilename = "";
>
> Index: clang/test/CodeGen/thinlto-split-dwarf.c
> ===================================================================
> --- /dev/null
> +++ clang/test/CodeGen/thinlto-split-dwarf.c
> @@ -0,0 +1,21 @@
> +// REQUIRES: x86-registered-target
> +
> +// RUN: %clang_cc1 -debug-info-kind=limited -triple
> x86_64-unknown-linux-gnu \
> +// RUN:   -flto=thin -emit-llvm-bc \
> +// RUN:   -o %t.o %s
> +
> +// RUN: llvm-lto2 run -thinlto-distributed-indexes %t.o \
> +// RUN:   -o %t2.index \
> +// RUN:   -r=%t.o,main,px
> +
> +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu \
> +// RUN:   -emit-obj -fthinlto-index=%t.o.thinlto.bc \
> +// RUN:   -o %t.native.o -split-dwarf-file %t.native.dwo -x ir %t.o
>

Can this be written in a single IR file yet (rather than frontend
compiling, indexing, then backend compiling), now that Teresa's implemented
some of the summary IR syntax?


> +
> +// RUN: llvm-readobj -sections %t.native.o | FileCheck --check-prefix=O %s
> +// RUN: llvm-readobj -sections %t.native.dwo | FileCheck
> --check-prefix=DWO %s
> +
> +// O-NOT: .dwo
> +// DWO: .dwo
> +
> +int main() {}
> Index: clang/lib/CodeGen/BackendUtil.cpp
> ===================================================================
> --- clang/lib/CodeGen/BackendUtil.cpp
> +++ clang/lib/CodeGen/BackendUtil.cpp
> @@ -1161,6 +1161,7 @@
>    Conf.DebugPassManager = CGOpts.DebugPassManager;
>    Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
>    Conf.RemarksFilename = CGOpts.OptRecordFile;
> +  Conf.DwoPath = CGOpts.SplitDwarfFile;
>    switch (Action) {
>    case Backend_EmitNothing:
>      Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20180531/f9140330/attachment-0001.html>