On Tue, 2019-11-19 at 04:57:10 UTC, Nathan Chancellor wrote: > When building pseries_defconfig, building vdso32 errors out: > > error: unknown target ABI 'elfv1' > > This happens because -m32 in clang changes the target to 32-bit, > which does not allow the ABI to be changed, as the setABI virtual > function is not overridden: > > https://github.com/llvm/llvm-project/blob/llvmorg-9.0.0/clang/include/clang/Basic/TargetInfo.h#L1073-L1078 > > https://github.com/llvm/llvm-project/blob/llvmorg-9.0.0/clang/lib/Basic/Targets/PPC.h#L327-L365 > > Commit 4dc831aa8813 ("powerpc: Fix compiling a BE kernel with a > powerpc64le toolchain") added these flags to fix building big endian > kernels with a little endian GCC. > > Clang doesn't need -mabi because the target triple controls the default > value. -mlittle-endian and -mbig-endian manipulate the triple into > either powerpc64-* or powerpc64le-*, which properly sets the default > ABI: > > https://github.com/llvm/llvm-project/blob/llvmorg-9.0.0/clang/lib/Driver/Driver.cpp#L450-L463 > > https://github.com/llvm/llvm-project/blob/llvmorg-9.0.0/llvm/lib/Support/Triple.cpp#L1432-L1516 > > https://github.com/llvm/llvm-project/blob/llvmorg-9.0.0/clang/lib/Basic/Targets/PPC.h#L377-L383 > > Adding a debug print out in the PPC64TargetInfo constructor after line > 383 above shows this: > > $ echo | ./clang -E --target=powerpc64-linux -mbig-endian -o /dev/null - > Default ABI: elfv1 > > $ echo | ./clang -E --target=powerpc64-linux -mlittle-endian -o /dev/null - > Default ABI: elfv2 > > $ echo | ./clang -E --target=powerpc64le-linux -mbig-endian -o /dev/null - > Default ABI: elfv1 > > $ echo | ./clang -E --target=powerpc64le-linux -mlittle-endian -o /dev/null - > Default ABI: elfv2 > > Don't specify -mabi when building with clang to avoid the build error > with -m32 and not change any code generation. > > -mcall-aixdesc is not an implemented flag in clang so it can be > safely excluded as well, see commit 238abecde8ad ("powerpc: Don't > use gcc specific options on clang"). > > pseries_defconfig successfully builds after this patch and > powernv_defconfig and ppc44x_defconfig don't regress. > > Link: https://github.com/ClangBuiltLinux/linux/issues/240 > Reviewed-by: Daniel Axtens <d...@axtens.net> > Signed-off-by: Nathan Chancellor <natechancel...@gmail.com>
Series applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/465bfd9c44dea6b55962b5788a23ac87a467c923 cheers
