RFA: Fix a disassembly/line-number bug

RFA: Fix a disassembly/line-number bug

[Daniel Jacobowitz]

[Please CC me, I don't read insight@]

This code is duplicated in GDB (MI), and I just fixed a bug there.  What
Insight has appears to be support for the (now defunct, as far as I can
tell) stabs live range splitting markers that Cygnus wrote, once upon a
time.  These no longer crop up, and a 0 in the line table has gotten a new
meaning in GDB: End of function.  The best thing to do is probably to skip
them if we see them.

Is this patch OK?


-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

2002-04-04  Daniel Jacobowitz  <drow@mvista.com>

        * generic/gdbtk-cmds.c (gdb_disassemble_driver): Skip
        end-of-function markers in the line table.

Index: gdbtk-cmds.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbtk/generic/gdbtk-cmds.c,v
retrieving revision 1.55
diff -u -p -r1.55 gdbtk-cmds.c
--- gdbtk-cmds.c	2002/04/01 22:29:21	1.55
+++ gdbtk-cmds.c	2002/04/04 20:21:39
@@ -2128,24 +2128,11 @@ gdb_disassemble_driver (CORE_ADDR low, C
               && le[i].pc == le[i + 1].pc)
             continue;		/* Ignore duplicates */
 
-	  /* GCC sometimes emits line directives with a linenumber
-	     of 0.  It does this to handle live range splitting.
-	     This may be a bug, but we need to be able to handle it.
-	     For now, use the previous instructions line number.
-	     Since this is a bit of a hack anyway, we will just lose
-	     if the bogus sline is the first line of the range.  For
-	     functions, I have never seen this to be the case.  */
-	  
-	  if (le[i].line != 0)
-	    {
-	      mle[newlines].line = le[i].line;
-	    }
-	  else
-	    {
-	      if (newlines > 0)
-		mle[newlines].line = mle[newlines - 1].line;
-	    }
-	  
+	  /* Skip any end-of-function markers.  */
+	  if (le[i].line == 0)
+	    continue;
+
+	  mle[newlines].line = le[i].line;
           if (le[i].line > le[i + 1].line)
             out_of_order = 1;
           mle[newlines].start_pc = le[i].pc;

Re: RFA: Fix a disassembly/line-number bug

[Keith Seitz]

On Thu, 4 Apr 2002, Daniel Jacobowitz wrote:

> Is this patch OK?

Sure. Thanks for thinking of us (me?).

Keith

> 2002-04-04  Daniel Jacobowitz  <drow@mvista.com>
>
>         * generic/gdbtk-cmds.c (gdb_disassemble_driver): Skip
>         end-of-function markers in the line table.
>
> Index: gdbtk-cmds.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbtk/generic/gdbtk-cmds.c,v
> retrieving revision 1.55
> diff -u -p -r1.55 gdbtk-cmds.c
> --- gdbtk-cmds.c	2002/04/01 22:29:21	1.55
> +++ gdbtk-cmds.c	2002/04/04 20:21:39
> @@ -2128,24 +2128,11 @@ gdb_disassemble_driver (CORE_ADDR low, C
>                && le[i].pc == le[i + 1].pc)
>              continue;		/* Ignore duplicates */
>
> -	  /* GCC sometimes emits line directives with a linenumber
> -	     of 0.  It does this to handle live range splitting.
> -	     This may be a bug, but we need to be able to handle it.
> -	     For now, use the previous instructions line number.
> -	     Since this is a bit of a hack anyway, we will just lose
> -	     if the bogus sline is the first line of the range.  For
> -	     functions, I have never seen this to be the case.  */
> -
> -	  if (le[i].line != 0)
> -	    {
> -	      mle[newlines].line = le[i].line;
> -	    }
> -	  else
> -	    {
> -	      if (newlines > 0)
> -		mle[newlines].line = mle[newlines - 1].line;
> -	    }
> -
> +	  /* Skip any end-of-function markers.  */
> +	  if (le[i].line == 0)
> +	    continue;
> +
> +	  mle[newlines].line = le[i].line;
>            if (le[i].line > le[i + 1].line)
>              out_of_order = 1;
>            mle[newlines].start_pc = le[i].pc;
>