[openmp] Test tasking/omp50_taskdep_depobj.c fails w/ standalone build unless openmp is installed first

[mgorny]

CC @jpeyton52

Looks to be a case of a missing -I flag:

FAIL: libomp :: tasking/omp50_taskdep_depobj.c (209 of 299)
******************** TEST 'libomp :: tasking/omp50_taskdep_depobj.c' FAILED ********************
Script:
--
: 'RUN: at line 1';   /usr/lib/ccache/bin/x86_64-pc-linux-gnu-clang -fno-experimental-isel -fopenmp   -I /tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp/runtime/test -L /tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp_build-abi_x86_64.amd64/runtime/src  -fno-omit-frame-pointer /tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp/runtime/test/tasking/omp50_taskdep_depobj.c -o /tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp_build-abi_x86_64.amd64/runtime/test/tasking/Output/omp50_taskdep_depobj.c.tmp && /tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp_build-abi_x86_64.amd64/runtime/test/tasking/Output/omp50_taskdep_depobj.c.tmp
--
Exit Code: 1

Command Output (stdout):
--
$ ":" "RUN: at line 1"
$ "/usr/lib/ccache/bin/x86_64-pc-linux-gnu-clang" "-fno-experimental-isel" "-fopenmp" "-I" "/tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp/runtime/test" "-L" "/tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp_build-abi_x86_64.amd64/runtime/src" "-fno-omit-frame-pointer" "/tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp/runtime/test/tasking/omp50_taskdep_depobj.c" "-o" "/tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp_build-abi_x86_64.amd64/runtime/test/tasking/Output/omp50_taskdep_depobj.c.tmp"
# command stderr:
/tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp/runtime/test/tasking/omp50_taskdep_depobj.c:8:10: fatal error: 'omp.h' file not found
#include <omp.h>
         ^~~~~~~
1 error generated.

error: command failed with exit status: 1

--

********************

FWICS the file is in:

/tmp/portage/sys-libs/libomp-15.0.0.9999/work/openmp_build-abi_x86_64.amd64/runtime/src/omp.h

[llvmbot]

@llvm/issue-subscribers-openmp

[jpeyton52]

@mgorny , It's peculiar that a compiler would support the -fopenmp flag but not have its own omp.h to use. Does the test compiler /usr/lib/ccache/bin/x86_64-pc-linux-gnu-clang actually support OpenMP or is it ignoring all the OpenMP pragmas?

[mgorny]

It's a fresh build of clang (wrapped through ccache), it doesn't have libomp installed yet as we're testing prior to installing it.

[jpeyton52]

@mgorny

Thanks for the explanation. I've posted https://reviews.llvm.org/D130926 to fix. Can you test it out and make sure it solves this issue?

[jpeyton52]

I've posted the same patch at https://reviews.llvm.org/D131000 to fix this issue.

[mgorny]

@jpeyton52, could you confirm backporting to 15.x?