Does also-emit-llvm plugin option in gold plugin still work?

I installed LLVM gold plugin and can ran the example in http://llvm.org/docs/GoldPlugin.html#example1.

Then I tried to use it to build a big project. I set the environment variables like:
export CC="/usr/local/bin/clang -use-gold-plugin -Wl, -plugin-opt=also-emit-llvm"
export CXX="/usr/local/bin/clang++ -use-gold-plugin -Wl, -plugin-opt=also-emit-llvm"
export AR="/usr/bin/ar"
export NM="/usr/bin/nm"
export RANLIB=/bin/true #ranlib is not needed, and doesn’t support .bc files in .a
export CFLAGS="-O4"

==========================
Then I ran configure and make but got the following errors:
clang: warning: -Wl,: 'linker' input unused when '-c' is present
clang: warning: argument unused during compilation:
'-plugin-opt=also-emit-llvm'
CXX(target) llvm/Debug/obj.target/base/base/base64.o
clang: warning: -Wl,: 'linker' input unused when '-c' is present
clang: warning: argument unused during compilation:
'-plugin-opt=also-emit-llvm'
CXX(target) llvm/Debug/obj.target/base/base/event_recorder_stubs.o
clang: warning: -Wl,: 'linker' input unused when '-c' is present
clang: warning: argument unused during compilation:
'-plugin-opt=also-emit-llvm'
CXX(target) llvm/Debug/obj.target/base/base/file_descriptor_shuffle.o

Do you know how I can solve this problem? Thanks in advance.

Those are warnings. You can put the -Wl,-plugin-opt in LDFLAGS.

Open a bug if you think that we shouldn't warn for

clang -c -Wl,foo bar.c

Cheers,
Rafael