Bug#892428: pocl: FTBFS on x32: tries to build kernel/host/ for amd64

[Andreas Beckmann]

On 2018-03-09 17:11, Aaron M. Ucko wrote:
> Good question.  Copying the LLVM maintainers accordingly.

The problems started with 0.13-12 where we switched the buildsystem from autotools to cmake.

>From the 0.13-11 buildlog:
...
checking build system type... x86_64-pc-linux-gnux32
checking host system type... x86_64-pc-linux-gnux32
checking target system type... x86_64-pc-linux-gnux32
...
/usr/lib/llvm-3.8/bin/clang -I/usr/include/x86_64-linux-gnux32 --target=x86_64-pc-linux-gnux32 -march=westmere -D_CL_DISABLE_HALF ...
...

>From the 0.13-12 buildlog:
...
-- llvm-config's LLVM_HOST_TARGET is: x86_64-pc-linux-gnu
...
/usr/bin/clang-3.8 --target=x86_64-pc-linux-gnu -D_CL_DISABLE_HALF -march= ...
...


>From the 1.1~rc2-1 buildlog:
...
-- llvm-config's LLVM_HOST_TARGET is: x86_64-pc-linux-gnu
...
/usr/bin/clang-4.0 --target=x86_64-pc-linux-gnu -D_CL_DISABLE_HALF -march=x86-64 ...
...

The LLVM_HOST_TARGET setting comes from llvm-config-4.0 --host-target:

cmake/LLVM.cmake:
  run_llvm_config(LLVM_HOST_TARGET --host-target)

which seems to return a wrong value on x32.
Due to lack of a x32 porterbox I cannot test this myself.

at least on an amd64 host --target=x86_64-pc-linux-gnux32 seems to do the right thing:

$ clang-4.0 --target=x86_64-pc-linux-gnux32 -march=x86-64 -c -x c /dev/null -o o.o
$ file o.o
o.o: ELF 32-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped


Andreas