Re: [PATCH] Don't drop DECL_INITIAL if -g for DWARF2+ (PR fortran/55395)

[Richard Biener <rguenther at suse dot de>]

On Fri, 7 Dec 2012, Jakub Jelinek wrote:

> On Fri, Dec 07, 2012 at 12:23:03PM +0100, Richard Biener wrote:
> > > That would still mean we can fail bootstrap with -O2 -g1, if there is a
> > > DEBUG_IMPLICIT_PTR created during RTL expansion to some unused var, then
> > > that var's varpool node is varpool_remove_node removed and initializer
> > > cleared, and dwarf2out_finish would want to make_decl_rtl_for_debug again.
> > 
> > "fail"?  Well, dwarf2out_finish definitely has to care for no initializer
> > being in-place.  Does it somehow record that it was present somewhen
> > early and is confused later when it got dropped?  If so, why not always
> > decide late if there is an initializer?
> 
> How?  During expansion to create DEBUG_IMPLICIT_PTR argument, we need some
> RTL for the vars (and can't make it using make_decl_rtl, as that would
> affect code generation).  So, we use make_decl_rtl_for_debug that doesn't
> remember the RTL, but still it does all the processing make_decl_rtl
> normally does.  bss_initializer_p is called deeply from that somewhere.
> As I said in the PR/initial mail, the other option would be to come up with
> some other special value for this DECL_INITIAL has been forgotten, but
> it wasn't bss_initializer_p.  But that seems to be lots of work for very
> little gain (rarely used -g1).

Hmm.  Then make it DINFO_LEVEL_NONE and put in a fixme comment refering
to the bugreport.

Richard.