Re: GDB's OpenCL Tests

[Luis Machado <luis.machado@linaro.org>]

Since Ulrich Weigand (cc-ed) introduced this testcase, maybe he has some 
input on how it is supposed to work, or how the whole infrastructure is 
supposed to be configured.

I don't run those myself. We should probably fix this and make them easy 
to run, with clear instructions on what is needed to get them going.

On 6/2/20 8:06 AM, Andrew Burgess wrote:
> I wonder if anyone is regularly running the OpenCL tests for GDB?
> 
> I'm running Fedora 31.  Initially None of the OpenCL tests would run
> due to the libOpenCL library being missing, so I installed the
> packages `ocl-icd', `ocl-icd-devel', and `opencl-headers'.  After this
> I did have libOpenCL.so, but things were still not working.
> 
> I was mostly looking at the gdb.opencl/callfuncs.exp test, just
> because it was the first test file, but I don't believe it is anything
> special, in fact, the failures I was seeing came from the file
> gdb/testsuite/lib/opencl.exp function skip_opencl_tests, when we're
> just checking if opencl is supported or not.
> 
> The compile was failing with this message:
> 
>    /usr/include/CL/cl_version.h:34:9: note: #pragma message: cl_version.h: CL_TARGET_OPENCL_VERSION is not defined. Defaulting to 220 (OpenCL 2.2)
>     34 | #pragma message("cl_version.h: CL_TARGET_OPENCL_VERSION is not defined. Defaulting to 220 (OpenCL 2.2)")
>        |         ^~~~~~~
> 
> This is actually just a warning, but this is still enough to cause
> GDB's testsuite to abandon the build.
> 
> A quick google, and "random internet stranger" recommended adding
> something like:
> 
>     #define CL_TARGET_OPENCL_VERSION 120
> 
> to the offending source files, so I added this to:
> 
>    gdb/testsuite/lib/cl_util.c
>    gdb/testsuite/lib/opencl_hostapp.c
> 
> I'm aware that at this point I'm just making random changes, so it's
> not really surprising that nothing after this works, but lets push
> on...
> 
> .... success, things now compile, but, almost all the tests are still
> failing.
> 
> What I see is this pattern in basically every test:
> 
>    (gdb) tbreak testkernel
>    Function "testkernel" not defined.
>    Make breakpoint pending on future shared library load? (y or [n]) y
>    Temporary breakpoint 1 (testkernel) pending.
>    (gdb) PASS: gdb.opencl/datatypes.exp: Set pending breakpoint
>    run
>    ....
>    [Inferior 1 (process 2840279) exited normally]
>    (gdb) FAIL: gdb.opencl/datatypes.exp: run (the program exited)
> 
> The 'testkernel' seems to be the core entry point function within the
> actual opencl program, so we never hit that symbol.
> 
> It was at this point that I started to grow suspicious that nobody is
> running these tests much (or at all?), the gdb.opencl/callfuncs.exp
> test contains this gem:
> 
>    gdb_load ${objdir}/${subdir}/${testfile}
> 
> Which doesn't take account of the /output/ directory that was added
> into the directory structure ages ago.  I applied patch #1 (below) to
> fix this.
> 
> Still not hitting the testkernel symbol...
> 
> So now I ran the test manually under GDB, break at 'exit' and then
> 'rbreak testkernel', this sets 3 breakpoints for me.  Start the test
> up again with 'run', and I hit one of the breakpoints, here's what I
> see:
> 
>    Thread 25 "callfuncs" hit Breakpoint 3, 0x00007ffff7fc9354 in _pocl_kernel_testkernel_workgroup ()
>       from /home/andrew/.cache/pocl/kcache/BA/OLMGEJJKCCPFCOMNNHDOJKFDNOKMKEPPCEIPJ/testkernel/16-1-1-goffs0-smallgrid/testkernel.so
>    (gdb) bt
>    #0  0x00007ffff7fc9354 in _pocl_kernel_testkernel_workgroup ()
>       from /home/andrew/.cache/pocl/kcache/BA/OLMGEJJKCCPFCOMNNHDOJKFDNOKMKEPPCEIPJ/testkernel/16-1-1-goffs0-smallgrid/testkernel.so
>    #1  0x00007ffff070fe6d in pocl_pthread_driver_thread () from /lib64/libpocl.so.2.5.0
>    #2  0x00007ffff1d324e2 in start_thread () from /lib64/libpthread.so.0
>    #3  0x00007ffff7d7a6a3 in clone () from /lib64/libc.so.6
> 
> I then use 'objdump -W' to look at the debug information in
> testkernel.so, and it has no extra debug at all.
> 
> So, my questions:
> 
>   - Can anyone successfully run some or all of the OpenCL tests?
> 
>   - And can anyone give me any hints on what I might need to do to get
>     the tests running?
> 
> Thanks,
> Andrew
> 
> ---
> 
> ## START - Patch 1 ##
> 
> diff --git a/gdb/testsuite/gdb.opencl/callfuncs.exp b/gdb/testsuite/gdb.opencl/callfuncs.exp
> index cf418d16582..1452c403c90 100644
> --- a/gdb/testsuite/gdb.opencl/callfuncs.exp
> +++ b/gdb/testsuite/gdb.opencl/callfuncs.exp
> @@ -33,12 +33,7 @@ if { [gdb_compile_opencl_hostapp "${clprogram}" "${testfile}" "" ] != "" } {
>       return -1
>   }
>   
> -gdb_exit
> -gdb_start
> -
> -# Load the OpenCL app
> -gdb_reinitialize_dir $srcdir/$subdir
> -gdb_load ${objdir}/${subdir}/${testfile}
> +clean_restart ${testfile}
>   
>   # Set breakpoint at the OpenCL kernel
>   gdb_test "tbreak testkernel" \
> 
> ## END - Patch 1 ##
>