[LLVMdev] clang 3.5 with "-flto" does not generate .bc files

[Gaoyao Xiao]

Hello,

I am trying to use clang to generate bitcode file. I read in
http://llvm.org/docs/GoldPlugin.html that clang with -flto option can
generate bitcode files. I have built LLVMgold.so and have gold with plugin
support. I tried "clang -c -flto toy.c -o toy.bc" and it does produce
bitcode. However, when I try it on lighttpd 1.4.35, then it only produce
the binary, but not produce bitcode of lighttpd. I also tried it on
apache2.0.56, and it create the errors like the following when linking.

/usr/bin/ld.gold.real: error: strings/.libs/apr_cpystrn.o:1:3: invalid
character
/usr/bin/ld.gold.real: error: strings/.libs/apr_cpystrn.o:1:3: syntax
error, unexpected $end
/usr/bin/ld.gold.real: error: strings/.libs/apr_cpystrn.o: not an object or
archive

I am using ubuntu 12.04. I have the following questions:
1) for lighttpd, why is it able to build but not produce bitcode?
2) for apache, does the error means that gold plugin is not found by clang
and make it fail to link? I read "-use-gold-plugin" can solve this problem
on clang 3.0. But this option is not recognized by clang 3.5. Will clang
3.0 solve this problem?

Many thanks!
Gaoyao
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