Hi Jeroen,
On Fri, 30 May 2014 15:45:27 +0200 Jeroen Hofstee jeroen@myspectrum.nl wrote:
Building u-boot tools with clang as a host compiler e.g. on FreeBSD with `gmake HOSTCC=clang CONFIG_USE_PRIVATE_LIBGCC=y tools` leads to many warnings [1] for every compiler invocation since commit 598e2d33. Part of mentioned commit imports linux patches:
- kbuild: LLVMLinux: Adapt warnings for compilation with clang
- kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
No version of clang supports the gcc fno-delete-null-pointer-checks though, but it is only passed to clang. Gcc does not have the clang specific Qunused-arguments for the target. Furthermore several warnings are disabled which aren't encountered in u-boot. Since such a build has worked for quite some time and works after removing these changes, just remove the clang specific handling to restore normal building with clang as hostcc.
I have to admit I just copied these line from Kernel without testing it, just for syncing with Kernel makefiles.
As far as I tested, Clang did not recognize -fno-delete-null-pointer-checks.
It is OK with me if you rip Clang stuff off the top Makefile.
Sorry, honestly I am not familiar enough with Clang to make deeper review.
This might be useful information for you. some discussion why Linux folks added those lines: https://patchwork.kernel.org/patch/3719881/
Do you also need this to use Clang? https://patchwork.kernel.org/patch/3720041/
Best Regards Masahiro Yamada