r365887 - [JSONCompilationDatabase] Strip distcc/ccache/gomacc wrappers from parsed commands.

Russell Gallop via cfe-commits cfe-commits at lists.llvm.org
Fri Jul 12 07:52:28 PDT 2019


Hi Sam,

This is hitting a test failure on a Windows bot:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/26916

Please could you take a look?

Thanks
Russ

On Fri, 12 Jul 2019 at 11:11, Sam McCall via cfe-commits <
cfe-commits at lists.llvm.org> wrote:

> Author: sammccall
> Date: Fri Jul 12 03:11:40 2019
> New Revision: 365887
>
> URL: http://llvm.org/viewvc/llvm-project?rev=365887&view=rev
> Log:
> [JSONCompilationDatabase] Strip distcc/ccache/gomacc wrappers from parsed
> commands.
>
> Summary:
> It's common to use compiler wrappers by setting CC="gomacc clang++".
> This results in both args appearing in compile_commands.json, and clang's
> driver
> can't handle this.
>
> This patch attempts to recognize this pattern (by looking for well-known
> wrappers) and dropping argv0 in this case.
>
> It conservatively ignores other cases for now:
>  - wrappers with unknown names
>  - wrappers that accept -flags
>  - wrappers where the compiler to use is implied (usually cc or gcc)
>
> This is done at the JSONCompilationDatabase level rather than somewhere
> more
> fundamental, as (hopefully) this isn't a general conceptual problem, but a
> messy
> aspect of the nature of the ecosystem around compile_commands.json.
> i.e. compilation databases more tightly tied to the build system should
> not have
> this problem.
>
> Reviewers: phosek, klimek
>
> Subscribers: llvm-commits
>
> Tags: #llvm
>
> Differential Revision: https://reviews.llvm.org/D64297
>
> Modified:
>     cfe/trunk/lib/Tooling/JSONCompilationDatabase.cpp
>     cfe/trunk/unittests/Tooling/CompilationDatabaseTest.cpp
>
> Modified: cfe/trunk/lib/Tooling/JSONCompilationDatabase.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Tooling/JSONCompilationDatabase.cpp?rev=365887&r1=365886&r2=365887&view=diff
>
> ==============================================================================
> --- cfe/trunk/lib/Tooling/JSONCompilationDatabase.cpp (original)
> +++ cfe/trunk/lib/Tooling/JSONCompilationDatabase.cpp Fri Jul 12 03:11:40
> 2019
> @@ -256,15 +256,57 @@ JSONCompilationDatabase::getAllCompileCo
>    return Commands;
>  }
>
> +static llvm::StringRef stripExecutableExtension(llvm::StringRef Name) {
> +  Name.consume_back(".exe");
> +  return Name;
> +}
> +
> +// There are compiler-wrappers (ccache, distcc, gomacc) that take the
> "real"
> +// compiler as an argument, e.g. distcc gcc -O3 foo.c.
> +// These end up in compile_commands.json when people set CC="distcc gcc".
> +// Clang's driver doesn't understand this, so we need to unwrap.
> +static bool unwrapCommand(std::vector<std::string> &Args) {
> +  if (Args.size() < 2)
> +    return false;
> +  StringRef Wrapper =
> +      stripExecutableExtension(llvm::sys::path::filename(Args.front()));
> +  if (Wrapper == "distcc" || Wrapper == "gomacc" || Wrapper == "ccache") {
> +    // Most of these wrappers support being invoked 3 ways:
> +    // `distcc g++ file.c` This is the mode we're trying to match.
> +    //                     We need to drop `distcc`.
> +    // `distcc file.c`     This acts like compiler is cc or similar.
> +    //                     Clang's driver can handle this, no change
> needed.
> +    // `g++ file.c`        g++ is a symlink to distcc.
> +    //                     We don't even notice this case, and all is
> well.
> +    //
> +    // We need to distinguish between the first and second case.
> +    // The wrappers themselves don't take flags, so Args[1] is a compiler
> flag,
> +    // an input file, or a compiler. Inputs have extensions, compilers
> don't.
> +    bool HasCompiler =
> +        (Args[1][0] != '-') &&
> +
> !llvm::sys::path::has_extension(stripExecutableExtension(Args[1]));
> +    if (HasCompiler) {
> +      Args.erase(Args.begin());
> +      return true;
> +    }
> +    // If !HasCompiler, wrappers act like GCC. Fine: so do we.
> +  }
> +  return false;
> +}
> +
>  static std::vector<std::string>
>  nodeToCommandLine(JSONCommandLineSyntax Syntax,
>                    const std::vector<llvm::yaml::ScalarNode *> &Nodes) {
>    SmallString<1024> Storage;
> -  if (Nodes.size() == 1)
> -    return unescapeCommandLine(Syntax, Nodes[0]->getValue(Storage));
>    std::vector<std::string> Arguments;
> -  for (const auto *Node : Nodes)
> -    Arguments.push_back(Node->getValue(Storage));
> +  if (Nodes.size() == 1)
> +    Arguments = unescapeCommandLine(Syntax, Nodes[0]->getValue(Storage));
> +  else
> +    for (const auto *Node : Nodes)
> +      Arguments.push_back(Node->getValue(Storage));
> +  // There may be multiple wrappers: using distcc and ccache together is
> common.
> +  while (unwrapCommand(Arguments))
> +    ;
>    return Arguments;
>  }
>
>
> Modified: cfe/trunk/unittests/Tooling/CompilationDatabaseTest.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Tooling/CompilationDatabaseTest.cpp?rev=365887&r1=365886&r2=365887&view=diff
>
> ==============================================================================
> --- cfe/trunk/unittests/Tooling/CompilationDatabaseTest.cpp (original)
> +++ cfe/trunk/unittests/Tooling/CompilationDatabaseTest.cpp Fri Jul 12
> 03:11:40 2019
> @@ -370,6 +370,30 @@ TEST(findCompileArgsInJsonDatabase, Find
>    EXPECT_EQ("command4", FoundCommand.CommandLine[0]) << ErrorMessage;
>  }
>
> +TEST(findCompileArgsInJsonDatabase, ParsesCompilerWrappers) {
> +  std::vector<std::pair<std::string, std::string>> Cases = {
> +      {"distcc gcc foo.c", "gcc foo.c"},
> +      {"gomacc clang++ foo.c", "clang++ foo.c"},
> +      {"ccache gcc foo.c", "gcc foo.c"},
> +      {"ccache.exe gcc foo.c", "gcc foo.c"},
> +      {"ccache g++.exe foo.c", "g++.exe foo.c"},
> +      {"ccache distcc gcc foo.c", "gcc foo.c"},
> +
> +      {"distcc foo.c", "distcc foo.c"},
> +      {"distcc -I/foo/bar foo.c", "distcc -I/foo/bar foo.c"},
> +  };
> +  std::string ErrorMessage;
> +
> +  for (const auto &Case : Cases) {
> +    std::string DB = R"([{"directory":".", "file":"/foo.c", "command":")"
> +
> +                     Case.first + "\"}]";
> +    CompileCommand FoundCommand =
> +        findCompileArgsInJsonDatabase("/foo.c", DB, ErrorMessage);
> +    EXPECT_EQ(Case.second, llvm::join(FoundCommand.CommandLine, " "))
> +        << Case.first;
> +  }
> +}
> +
>  static std::vector<std::string> unescapeJsonCommandLine(StringRef
> Command) {
>    std::string JsonDatabase =
>      ("[{\"directory\":\"//net/root\", \"file\":\"test\", \"command\": \""
> +
>
>
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