Re: [RFC] "single step" atomic instruction sequences as a whole on PPC

["Ulrich Weigand" <uweigand@de.ibm.com>]

Daniel Jacobowitz wrote:
> On Thu, May 10, 2007 at 11:30:53PM +0200, Ulrich Weigand wrote:
> > This looks just like a problem we fixed for the combined debugger;
> > cancel_breakpoints_callback should cancel SIGTRAP events caused by
> > software single-step breakpoints just the same as those caused by
> > other breakpoints.
> 
> Maybe it would be more elegant to anticipate the day that single step
> breakpoints are completely normal: make breakpoint_inserted_here_p
> check them?  This is already the only caller.

Good point.  Something like the patch below?  I've also added the
check to software_breakpoint_inserted_here_p; that seemed to make
more sense that not.

(I'm suspicious about adjust_pc_after_break, the only caller of
software_breakpoint_inserted_here_p anyway; I think this may no 
longer be correct after the software single-step changes ...)

Bye,
Ulrich


ChangeLog:

	* breakpoint.c (single_step_breakpoint_inserted_here_p): New function.
	(breakpoint_inserted_here_p): Call it.
	(software_breakpoint_inserted_here_p): Likewise.


diff -urNp gdb-orig/gdb/breakpoint.c gdb-head/gdb/breakpoint.c
--- gdb-orig/gdb/breakpoint.c	2007-05-11 00:15:25.160082872 +0200
+++ gdb-head/gdb/breakpoint.c	2007-05-11 00:22:39.846579732 +0200
@@ -202,6 +202,8 @@ static void tcatch_command (char *arg, i
 
 static void ep_skip_leading_whitespace (char **s);
 
+static int single_step_breakpoint_inserted_here_p (CORE_ADDR pc);
+
 /* Prototypes for exported functions. */
 
 /* If FALSE, gdb will not use hardware support for watchpoints, even
@@ -1841,6 +1843,10 @@ breakpoint_inserted_here_p (CORE_ADDR pc
 	}
     }
 
+  /* Also check for software single-step breakpoints.  */
+  if (single_step_breakpoint_inserted_here_p (pc))
+    return 1;
+
   return 0;
 }
 
@@ -1872,6 +1878,10 @@ software_breakpoint_inserted_here_p (COR
 	}
     }
 
+  /* Also check for software single-step breakpoints.  */
+  if (single_step_breakpoint_inserted_here_p (pc))
+    return 1;
+
   return 0;
 }
 
@@ -7951,6 +7961,23 @@ remove_single_step_breakpoints (void)
     }
 }
 
+/* Check whether a software single-step breakpoint is inserted at PC.  */
+
+static int
+single_step_breakpoint_inserted_here_p (CORE_ADDR pc)
+{
+  int i;
+
+  for (i = 0; i < 2; i++)
+    {
+      struct bp_target_info *bp_tgt = single_step_breakpoints[i];
+      if (bp_tgt && bp_tgt->placed_address == pc)
+	return 1;
+    }
+
+  return 0;
+}
+
 \f
 /* This help string is used for the break, hbreak, tbreak and thbreak commands.
    It is defined as a macro to prevent duplication.

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com