Re: [PATCH] Remove zero PC check from blockframe.c:inside_main_func()

[Mark Kettenis <kettenis at chello dot nl>]

   Date: Sat, 13 Dec 2003 19:22:47 -0500
   From: Andrew Cagney <cagney@gnu.org>

   > RCS file: /cvs/src/src/gdb/frame.c,v
   > retrieving revision 1.153
   > diff -u -p -r1.153 frame.c
   > --- frame.c 10 Dec 2003 17:40:42 -0000 1.153
   > +++ frame.c 13 Dec 2003 21:47:43 -0000
   > @@ -1732,6 +1732,7 @@ struct frame_info *
   >  get_prev_frame (struct frame_info *this_frame)
   >  {
   >    struct frame_info *prev_frame;
   > +  CORE_ADDR pc;
   >  
   >    if (frame_debug)
   >      {
   > @@ -1961,7 +1962,8 @@ get_prev_frame (struct frame_info *this_
   >       because (well ignoring the PPC) a dummy frame can be located
   >       using THIS_FRAME's frame ID.  */
   >  
   > -  if (frame_pc_unwind (this_frame) == 0)
   > +  pc = frame_pc_unwind (this_frame);
   > +  if (this_frame->level >= 0 && pc == 0)
   >      {
   >        /* The allocated PREV_FRAME will be reclaimed when the frame
   >  	 obstack is next purged.

   Can it be deleted?

I think so.  I tested i386-unknown-freebsd4.7, i386-pc-solaris2.9,
x86_64-unknown-freebsd5.2 and alpha-unknown-freenbsd5.2, and things
didn't change.

   This would likely affect the initial call sequence made to the unwinder 
   - frame_pc_unwind may not be called first (?).  But I also think that 
   the reason for insisting on an explicit pc unwind may have also been 
   removed - the new code is written more robustly anyway.

I think I agree.  So shall I remove the code?

Mark