https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=140532

2007-01-01  Jan Kratochvil <jan.kratochvil@redhat.com>

	* rs6000-tdep.c (skip_prologue): Handle bl->brlr used by PIC code.

diff -u -rup gdb-6.5-orig/gdb/rs6000-tdep.c gdb-6.5/gdb/rs6000-tdep.c

--- gdb-6.5-orig/gdb/rs6000-tdep.c	2006-12-30 15:53:52.000000000 -0500

+++ gdb-6.5/gdb/rs6000-tdep.c	2006-12-31 19:06:28.000000000 -0500

@@ -1182,6 +1182,40 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l

       else if ((op & 0xfc000001) == 0x48000001)

 	{			/* bl foo, 

 				   to save fprs??? */

+	  CORE_ADDR bl_target;

+	  gdb_byte bl_target_op_buf[4];

+

+	  /* Safely skip:

+	     prologue: ...

+		       bl addr

+		       ...

+	     addr:     blrl

+	     as it could break the prologue by `prologue_sal.line'

+	     or `prologue_sal.line != this_sal.line' conditions below.  */

+	  /* Sign-extend it to the upper 6 bits.  */

+	  if (op & 0x02000000)

+	    bl_target = pc + -(long) (((~op) & 0x03fffffc) + 4);

+	  else

+	    bl_target = pc + (op & 0x03fffffc);

+	  if (target_read_memory (bl_target, bl_target_op_buf, 4) == 0)

+	    {

+	      unsigned long bl_target_op;

+

+	      bl_target_op = extract_signed_integer (bl_target_op_buf, 4);

+	      if (bl_target_op == 0x4e800021)	/* blrl  */

+		{

+		  /* If we did not yet retrieved LR into some GPR

+		     all our chances are lost.  On the other hand already

+		     stored LR is still kept intact in its GPR.  */

+		  if (lr_reg == -1)

+		    {

+		      /* Invalidate lr_reg, but don't set it to -1.

+			 That would mean that it had never been set.  */

+		      lr_reg = -2;

+		    }

+		  continue;

+		}

+	    }

 	  fdata->frameless = 0;

 	  /* Don't skip over the subroutine call if it is not within