Re: RFA: Check for corruption of cv_type chain

[Jim Blandy <jimb@redhat.com>]

Daniel Jacobowitz <drow@mvista.com> writes:
> On Fri, May 03, 2002 at 07:10:21PM -0500, Jim Blandy wrote:
> > 
> > Daniel Jacobowitz <drow@mvista.com> writes:
> > > On Fri, May 03, 2002 at 04:54:23PM -0500, Jim Blandy wrote:
> > > 
> > > > ! # These tests are intended to catch problems in the STABS reader, so I
> > > > ! # think it's okay to override the preference the user expressed in
> > > > ! # their $DEJAGNU file or whatever, and explicitly request extended
> > > > ! # stabs debugging information.  But, if we don't know how to do that,
> > > > ! # these tests still should pass just fine if the executable uses some
> > > > ! # other format.
> > > > ! #
> > > > ! # Plain old -gstabs isn't enough, by the way.  See the notes for
> > > > ! # "doesn't corrupt cv_type chain", below.
> > > > ! if {$gcc_compiled} {
> > > > !     set debug_option additional_flags=-gstabs+
> > > > ! } else {
> > > > !     set debug_option debug
> > > > ! }
> > > > ! set options [list c++ $debug_option]
> > > 
> > > Please don't... -gstabs+ is a configuration; if we test that
> > > configuration, which is the default pre-3.1, then we will see the bug. 
> > > If I run a DWARF-2 testsuite explicitly I don't really want to look at
> > > bugs in the stabs reader.
> > 
> > It doesn't seem to the default pre-3.1.  -gstabs is.  (I think.)
> 
> No, -gstabs+ is definitely the default.  Our C++ debugging with -gstabs
> is practically nil, so we'd notice :)

[goes and checks his compilers] I see what's going on now.  In GCC
2.96, -g doesn't get you `const' and `volatile' qualifiers in stabs
--- that's why I thought -gstabs was the default.  But in fact, GCC
2.96 won't give you those qualifiers no matter how nicely you ask.

The current GCC sources default to Dwarf 2.  So except for the
window between the point where we taught dbxout.c to emit the
qualifiers, and the point where we made Dwarf 2 the default (a pretty
narrow window, in terms of installed base, no?), it doesn't matter
whether -gstabs+ is the default or not; this test won't do its job
with the default flags.

Oh well.  If someone is explicitly interested in -gstabs+, they should
run the test suite with that flag, and then the test will do its job.
I guess I shouldn't worry about it any more.