Re: [PATCH] testsuite: analyzer: expect alignment warning with -fshort-enums

[David Malcolm <dmalcolm@redhat.com>]

On Sun, 2023-11-19 at 08:13 -0700, Jeff Law wrote:
> 
> 
> On 11/19/23 00:36, Alexandre Oliva wrote:
> > 
> > On targets that have -fshort-enums enabled by default, the type
> > casts
> > in the pr108251 analyzer tests warn that the byte-aligned enums may
> > not be sufficiently aligned to be a struct connection *.  The
> > function
> > can't know better, the warning is reasonable, the code doesn't
> > expected enums to be shorter and less aligned than the struct.
> > 
> > Rather than use -fno-short-enums, I decided to embrace the warning
> > on
> > targets that have short_enums enabled by default.
> > 
> > However, C++ doesn't issue the warning, because even with
> > -fshort-enums, enumeration types are not TYPE_PACKED, and the
> > expression is not sufficiently simplified by the C++ front-end for
> > check_and_warn_address_or_pointer_of_packed_member to identify the
> > insufficiently aligned pointer.  So don't expect the warning there.
> > 
> > (I've got followup patches in testing to get the same warnings in
> > C++)
> > 
> > Regstrapped on x86_64-linux-gnu, also tested on arm-eabi with
> > default
> > cpu on trunk, and with tms570 on gcc-13.  Ok to install?
> > 
> > 
> > for  gcc/testsuite/ChangeLog
> > 
> >         * c-c++-common/analyzer/null-deref-pr108251-
> > smp_fetch_ssl_fc_has_early-O2.c:
> >         Expect "unaligned pointer value" warning on short_enums
> >         targets, but not in c++.
> >         * c-c++-common/analyzer/null-deref-pr108251-
> > smp_fetch_ssl_fc_has_early.c:
> >         Likewise.
> OK.  Hell of a filename for a single test :-)

Sorry about that, I have lots of test names of the form prNNNNNN and
wanted something more descriptive.  Clearly I overcorrected :)

Dave