new bridgetest failures in 7.6 on ppc64le

[Dan Horák]

On Thu, 5 Oct 2023 17:46:13 +0200
Dan Horák <dan at danny.cz> wrote:

> On Thu, 5 Oct 2023 17:11:55 +0200
> Stephan Bergmann <sbergman at redhat.com> wrote:
> 
> > On 10/5/23 10:38, Dan Horák wrote:
> > > I would appreciate any tips and tricks how to attack this problem with
> > > gdb, because I wasn't successful in getting into the right place or
> > > process and relied mainly on the old school "printf" method :-)
> > 
> > The call
> > 
> > >             TwoFloats aOut = xLBT->echoTwoFloats(aIn);
> > 
> > at testtools/source/bridgetest/bridgetest.cxx:474 goes to a dynamically 
> > created stub, generated at runtime by codeSnippet in 
> > bridges/source/cpp_uno/gcc3_linux_powerpc64/cpp2uno.cxx, which calls 
> > privateSnippetExecutor, which calls cpp_mediate, which (in its case 
> > typelib_TypeClass_INTERFACE_METHOD case's default case) calls 
> > cpp2uno_call, which at
> > 
> > >     // invoke uno dispatch call
> > >     (*pThis->getUnoI()->pDispatcher)( pThis->getUnoI(), pMemberTypeDescr, pUnoReturn, pUnoArgs, &pUnoExc );
> > 
> > calls into the binary UNO to Java bridge.  So if you assume that things 
> > are fine between binary UNO and Java (which is a reasonable assumption, 
> > as that part should be mostly architecture-agnostic), I'd start to debug 
> > at the return of that pDispatcher call, and see how its return value 
> > (i.e., the return value from
> > 
> > >         public TwoFloats echoTwoFloats( TwoFloats i_Struct) throws com.sun.star.uno.RuntimeException {
> > >             return i_Struct;
> > >         }
> > 
> > in testtools/com/sun/star/comp/bridge/TestComponent.java) propagates 
> > back down to the original C++ call at 
> > testtools/source/bridgetest/bridgetest.cxx:474.
> > 
> 
> thanks and for the record, with https://fedora.danny.cz/ppc/bridge-debug.patch
> I am getting https://fedora.danny.cz/ppc/bridge-debug.log after "make unitcheck"
> under testtools/
> 
> You can see both the C++ and Java test running (IMO good for comparison)
> and when the struct is translated from Java to UNO, it still looks good
> (IMHO), search for "STRUCT top-level". Then the "f1" and "f2" prints from
> right after https://git.libreoffice.org/core/+/refs/heads/master/bridges/source/cpp_uno/gcc3_linux_powerpc64/uno2cpp.cxx#218
> they are bad.
> 
> I will look further especially at the dynamically generated stubs,
> which is new to me. Apply those stubs to the C++ bridge as well?

rough guess, but we might be missing something like
https://git.libreoffice.org/core/+/refs/heads/master/bridges/source/cpp_uno/gcc3_linux_aarch64/cpp2uno.cxx#352


		Dan