[PATCH] D27603: Propagate -fdiagnostics-color to LLD.

[Rui Ueyama via Phabricator via cfe-commits]

ruiu added inline comments.


================
Comment at: lib/Driver/Tools.cpp:284
+  // propagate -fdiagnostics-color.
+  if (StringRef(TC.GetLinkerPath()).endswith("ld.lld") &&
+      D.getDiags().getShowColors())
----------------
rsmith wrote:
> I don't think this will work for `-fuse-ld=$BINDIR/lld` and the like. We also have code around Tools.cpp doing things like this:
> 
>     const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
>     if (llvm::sys::path::filename(Exec) == "lld") {
> 
> and
> 
>     const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
>     if (llvm::sys::path::stem(Exec).equals_lower("lld")) {
> 
> so detecting `ld.lld` here seems inconsistent. (Meanwhile, the above checks won't fire for `-fuse-ld=lld`, since that sets the linker path to .../ld.lld.)
> 
> I think it's time to factor out an `isLinkerLLD` function and use that to detect whether we're using lld.
What if a linker is just `/usr/bin/ld`? I want to detect if it's LLD or not, but it's not doable without running that command. (If we pass it via the environment, we can always set LLD_COLOR_DIAGNOSTICS=1 though.)


https://reviews.llvm.org/D27603