[cfe-dev] Changing the way Clang's driver computes the library search paths on Linux

[Miles Bader]

Chandler Carruth <chandlerc at google.com>
writes:
> Most of this is committed as of r141000. Both detection of GCC installations
> and the basic system library paths respect system roots, and the pattern
> matches that of GCC as closely as I could, and appears to be compatible with
> the layout of most of the distributions I tested it on.
>
> There is more work to be done to make the triple-detection and installation
> detection more sysroot aware, and more intelligent. There is also work to be
> done to remove several of the distribution-specific kludges that are no
> longer needed, and to properly support the new Debian multiarch structure.
> I'm also seeing oddities in Ubuntu multilib paths that I'm hoping to
> correct, but these were pre-existing.
>
> If folks see issues, please let me know and I'll try to respond promptly.

It certainly doesn't work on debian yet (sorry if you already knew
that; it's not so clear from what you wrote above what "properly
support" means).

   $ clang-trunk -o hw ~/src/hw.c
   /usr/bin/ld: error: cannot open crt1.o: No such file or directory
   /usr/bin/ld: error: cannot open crti.o: No such file or directory
   /usr/bin/ld: error: cannot open crtn.o: No such file or directory
   clang: error: linker command failed with exit code 1 (use -v to see invocation)

   $ clang-trunk --version
   clang version 3.0 (http://llvm.org/git/clang.git f4e541ccecfc06e9818fba83e7ac3a072b1d849e)
   Target: x86_64-unknown-linux-gnu
   Thread model: posix

The above "crt*.o" files seem to exist in two places on this system:

   /usr/lib/x86_64-linux-gnu/
   /usr/lib32/

[presumably for use with 64-bit or 32-bit compiles]

-Miles

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