RE: [PATCH V3] PowerPC: fix for gdb.base/eh_return.exp

[Carl Love via Gdb-patches <gdb-patches@sourceware.org>]

On Wed, 2022-06-08 at 19:32 +0100, Pedro Alves wrote:
> On 2022-06-02 17:52, Carl Love wrote:
> > Kevin:
> > 
> > On Wed, 2022-05-11 at 15:48 -0700, Kevin Buettner wrote:
> > > On Wed, 11 May 2022 14:52:32 -0700
> > > Carl Love <cel@us.ibm.com> wrote:
> > > 
> > > > +    # Disable the Traceback Table generation, using the
> > > > PowerPC
> > > > specific
> > > > +    # gcc option, so the test gdb_test_multiple "disassemble
> > > > eh2"
> > > > will match
> > > 
> > > What happens when some compiler other than gcc is used to run the
> > > test?
> > 
> > I updated the patch to set the compiler options for gcc and
> > XLC.  The
> > test was run on AIX and passes with the patch.  Note that AIX
> > actually
> > uses gcc to compile gdb.  We tried compiling gdb with the xlc
> > compiler.
> > We ran into other gdb compilation errors that we were not able to
> > resolve.  We were able to verify that the xlc options to disable
> > the
> > Traceback Buffer were right but that was it.  
> 
> The compiler used to build gdb does not have to be the same used to
> run tests.  You can build gdb with gcc as usual, and then run tests
> with some other compiler, like:
> 
>  $ make check RUNTESTFLAGS="CC_FOR_TARGET=foo CXX_FOR_TARGET=foo++"

I asked the AIX person about using gdb compiled with gdb but compiling
the test case with xlc.  Here is his reply:

   I used gcc to compile gdb as it’s not easy to compile gdb with xlc.
   To use the xlc for compiling test programs I have modified the site.exp 
   file with the Option “CC_FOR_TARGET” & “CXX_FOR_TARGET” to point to xlc 
   binary path along with proper CFLAGS & CXXFLAGS.
    
   I confirmed that for compiling the eh_return.c xlc compiler is being used.
    
   Here is the compilation output.
    
   builtin_spawn -ignore SIGHUP /opt/IBM/xlc/16.1.0/bin/xlc -q64 -g -O0 -w  
   -qdbgfmt=dwarf -c -g -o /.../gdb/testsuite/outputs/gdb.base/eh_return/eh_return0.o 
   /.../gdb/testsuite/gdb.base/eh_return.c

   But since test program eh_return.c was written with gcc in mind it wasn’t able
   to compile and giving the undefined error.  gdb compile failed, 
    ld: 0711-317 ERROR: Undefined symbol: .__builtin_eh_return.

So unfortunately, he wasn't able to actually run the gdb test but was
able to verify the compilation of the test.  

                  Carl Love