From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stan Shebs To: Kevin Buettner Cc: David Edelsohn , Elena Zannoni , Zack Weinberg , Matthew Conway , Mark Mitchell , gcc-patches@gcc.gnu.org, gdb@sources.redhat.com Subject: Re: Limited success with 3.0 branch on AIX Date: Wed, 16 May 2001 14:06:00 -0000 Message-id: <3B02EB6E.F4F74251@apple.com> References: <200105162006.QAA25648@makai.watson.ibm.com> <1010516205027.ZM11789@ocotillo.lan> X-SW-Source: 2001-05/msg00282.html Kevin Buettner wrote: > > /* Version of GCC used to compile the function corresponding > to this block, or 0 if not compiled with GCC. When possible, > GCC should be compatible with the native compiler, or if that > is not feasible, the differences should be fixed during symbol > reading. As of 16 Apr 93, this flag is never used to distinguish > between gcc2 and the native compiler. (page page page...) My creaky and failing memory recalls configs where GCC did not produce code that was 100% compatible with the vendor compiler, for instance in the area of struct returns. So GDB needed to know which convention was in use, and in the absence of better hints (such as when -g wasn't specified), the gcc2_compiled symbol would get the info through. (It matters for the non-debug case because we may need to walk through non-debug frames to get to the frames of interest.) I think it's still possible to use GCC in a way that makes the label necessary, for instance by using some of the more dubious flags in some of the more obscure configs, but I doubt that PowerPC is one of them. I'd suggest blasting this old stuff anyway, adding a cautionary note to the internals manual ("don't let the compiler do this, ever" and reopening the issue afresh should it come up again. Stan