Re: [RFA] stack.c: Always set current_source_{symtab,line}

[Keith Seitz <keiths at redhat dot com>]

On Thu, 29 Aug 2002, Elena Zannoni wrote:

> Ok, I am going to be a PITA: does this odd behavior occur with non-mi
> gdb?  I am not clear on why it is happening only with mi. Or at
> least I don't see it in regular gdb.

This happens because we suppress printing the listing when we stop 
(infrun.c/normal_stop):

      if (stop_print_frame && selected_frame)
	{
	  int bpstat_ret;
	  int source_flag;
	  int do_frame_printing = 1;

	  bpstat_ret = bpstat_print (stop_bpstat);
	  switch (bpstat_ret)
	    {
	    case PRINT_UNKNOWN:
	      if (stop_step
		  && step_frame_address == FRAME_FP (get_current_frame ())
		  && step_start_function == find_pc_function (stop_pc))
		source_flag = SRC_LINE;	/* finished step, just print source line */
	      else
		source_flag = SRC_AND_LOC;	/* print location and source line */
	      break;
	    case PRINT_SRC_AND_LOC:
	      source_flag = SRC_AND_LOC;	/* print location and source line */
	      break;
	    case PRINT_SRC_ONLY:
	      source_flag = SRC_LINE;
	      break;
	    case PRINT_NOTHING:
	      source_flag = SRC_LINE;	/* something bogus */
	      do_frame_printing = 0;
	      break;
	    default:
	      internal_error (__FILE__, __LINE__, "Unknown value.");
	    }
	  /* For mi, have the same behavior every time we stop:
	     print everything but the source line. */
	  if (ui_out_is_mi_like_p (uiout))
	    source_flag = LOC_AND_ADDRESS;

We use LOC_AND_ADDRESS to suppress source listings, but a side affect is 
that it doesn't set current_source_symtab, either, because 
current_source_symtab is set in print_source_lines_base, called from 
print_source_lines, from print_frame_info_base:

  source_print = (source == SRC_LINE || source == SRC_AND_LOC);

  if (source_print && sal.symtab)
    {
      int done = 0;
      int mid_statement = (source == SRC_LINE) && (fi->pc != sal.pc);

      if (annotation_level)
	done = identify_source_line (sal.symtab, sal.line, mid_statement,
				     fi->pc);
      if (!done)
	{
	  if (print_frame_info_listing_hook)
	    {
	      print_frame_info_listing_hook (sal.symtab, sal.line, sal.line + 1, 0);
	      current_source_symtab = sal.symtab;
	    }
	  else
	    {
	      /* We used to do this earlier, but that is clearly
		 wrong. This function is used by many different
		 parts of gdb, including normal_stop in infrun.c,
		 which uses this to print out the current PC
		 when we stepi/nexti into the middle of a source
		 line. Only the command line really wants this
		 behavior. Other UIs probably would like the
		 ability to decide for themselves if it is desired. */
	      if (addressprint && mid_statement)
		{
		  ui_out_field_core_addr (uiout, "addr", fi->pc);
		  ui_out_text (uiout, "\t");
		}

	      print_source_lines (sal.symtab, sal.line, sal.line + 1, 0);
	    }
	}
      current_source_line = max (sal.line - lines_to_list / 2, 1);
    }

Keith