clang requires libgcc from the gcc package to compile anything

[joakim-noah]

Consider packaging libgcc or llvm's replacement, compiler-rt, as a standalone package that clang could install as a dependency instead, spun off from #63.

[fornwall]

It seems that compiler-rt only supports i386 and x86_64 when cross compiling, from this section in make/platform/clang_linux.mk:

# We don't currently have any general purpose way to target architectures other
# than the compiler defaults (because there is no generalized way to invoke
# cross compilers). For now, we just find the target architecture of the
# compiler and only define configurations we know that compiler can generate.
CompilerTargetTriple := $(shell \
        LANG=C $(CC) -v 2>&1 | grep 'Target:' | cut -d' ' -f2)
ifeq ($(CompilerTargetTriple),)
$(error "unable to infer compiler target triple for $(CC)")
endif

# Only define configs if we detected a linux target.
ifneq ($(findstring -linux-,$(CompilerTargetTriple)),)

# Define configs only if arch in triple is i386 or x86_64
CompilerTargetArch := $(firstword $(subst -, ,$(CompilerTargetTriple)))
ifeq ($(call contains,i386 x86_64,$(CompilerTargetArch)),true)```

[joakim-noah]

OK, I never tried building compiler-rt, just knew it was the llvm equivalent. I see that there's one in the Android source tree, maybe that one can be used? Or maybe compiler-rt is already available on Android devices somewhere and can be linked against?

[fornwall]

This has now been fixed in the 3.8.0-1 version of the clang package, which depends on the new libgcc package which just contains $PREFIX/lib/libgcc.a taken from the NDK.

If I read the structure right the clang used in the NDK itself uses libgcc, so it's probably the best way forward for now.

[joakim-noah]

Thanks, verified that this works for a medium-size C++ codebase.