Re: [PATCH v2 2/2] perf clang: Fixes for more recent LLVM/clang

["Fāng-ruì Sòng" <maskray@google.com>]

On Mon, Oct 11, 2021 at 7:13 PM Ian Rogers <irogers@google.com> wrote:
>
> The parameters to two functions and the location of a variable have
> changed in more recent LLVM/clang releases.
>
> Remove the unneecessary -fmessage-length and -ferror-limit flags, the
> former causes failures like:
>
> 58: builtin clang support                                           :
> 58.1: builtin clang compile C source to IR                          :
> --- start ---
> test child forked, pid 279307
> error: unknown argument: '-fmessage-length'
> 1 error generated.
> test child finished with -1
>
> Tested with LLVM 6, 8, 9, 10 and 11.
>
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/c++/clang.cpp | 21 +++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
> index c8885dfa3667..df7b18fb6b6e 100644
> --- a/tools/perf/util/c++/clang.cpp
> +++ b/tools/perf/util/c++/clang.cpp
> @@ -43,8 +43,6 @@ createCompilerInvocation(llvm::opt::ArgStringList CFlags, StringRef& Path,
>                 "-cc1",
>                 "-triple", "bpf-pc-linux",
>                 "-fsyntax-only",
> -               "-ferror-limit", "19",
> -               "-fmessage-length", "127",
>                 "-O2",
>                 "-nostdsysteminc",
>                 "-nobuiltininc",
> @@ -55,7 +53,11 @@ createCompilerInvocation(llvm::opt::ArgStringList CFlags, StringRef& Path,
>                 "-x", "c"};
>
>         CCArgs.append(CFlags.begin(), CFlags.end());
> -       CompilerInvocation *CI = tooling::newInvocation(&Diags, CCArgs);
> +       CompilerInvocation *CI = tooling::newInvocation(&Diags, CCArgs
> +#if CLANG_VERSION_MAJOR >= 11
> +                                                        ,/*BinaryName=*/nullptr
> +#endif
> +                                                        );
>
>         FrontendOptions& Opts = CI->getFrontendOpts();
>         Opts.Inputs.clear();
> @@ -151,13 +153,16 @@ getBPFObjectFromModule(llvm::Module *Module)
>
>         legacy::PassManager PM;
>         bool NotAdded;
> -#if CLANG_VERSION_MAJOR < 7
> -       NotAdded = TargetMachine->addPassesToEmitFile(PM, ostream,
> -                                                     TargetMachine::CGFT_ObjectFile);
> +       NotAdded = TargetMachine->addPassesToEmitFile(PM, ostream
> +#if CLANG_VERSION_MAJOR >= 7
> +                                                      , /*DwoOut=*/nullptr
> +#endif
> +#if CLANG_VERSION_MAJOR < 10
> +                                                      , TargetMachine::CGFT_ObjectFile
>  #else
> -       NotAdded = TargetMachine->addPassesToEmitFile(PM, ostream, nullptr,
> -                                                     TargetMachine::CGFT_ObjectFile);
> +                                                      , llvm::CGFT_ObjectFile
>  #endif
> +                                                      );
>         if (NotAdded) {
>                 llvm::errs() << "TargetMachine can't emit a file of this type\n";
>                 return std::unique_ptr<llvm::SmallVectorImpl<char>>(nullptr);
> --
> 2.33.0.882.g93a45727a2-goog
>

Thanks for the change:)

Reviewed-by: Fangrui Song <maskray@google.com>