[commit] Check undebuggable after sigtramp; Was: [patch/rfc] Useinsert_step_resume_breakpoint everywhere

[Andrew Cagney <cagney at gnu dot org>]

> If you stepi into the trampoline, does gdb know that its got a signal trampoline?  When stepping, this code:
>
>   if (step_range_end != 1
>       && (step_over_calls == STEP_OVER_UNDEBUGGABLE
>           || step_over_calls == STEP_OVER_ALL)
>       && get_frame_type (get_current_frame ()) == SIGTRAMP_FRAME)
>     {
>       /* The inferior, while doing a "step" or "next", has ended up in
>          a signal trampoline (either by a signal being delivered or by
>          the signal handler returning).  Just single-step until the
>          inferior leaves the trampoline (either by calling the handler
>          or returning).  */
>       keep_going (ecs);
>       return;
>     }
>
> should be triggering causing the inferior to single step which makes it setting a breakpoint in main most puzzling.
>
> Try moving the above to before:
>
>   if (step_over_calls == STEP_OVER_UNDEBUGGABLE
>       && ecs->stop_func_name == NULL)
>     {
>       /* There is no symbol, not even a minimal symbol, corresponding
>          to the address where we just stopped.  So we just stepped
>          inside undebuggable code.  Since we want to step over this
>          kind of code, we keep going until the inferior returns from
>          the current function.  */
>       handle_step_into_function (ecs);
>       return;
>     }

Per the attached I've done this, I'm no longer seeing the panic.

committed,
Andrew

2004-05-13  Andrew Cagney  <cagney@redhat.com>

	* infrun.c (handle_inferior_event): Check for
	STEP_OVER_UNDEBUGGABLE after signal trampolines and function
	calls.

Index: infrun.c
===================================================================
RCS file: /cvs/src/src/gdb/infrun.c,v
retrieving revision 1.160
diff -p -u -r1.160 infrun.c
--- infrun.c	13 May 2004 18:42:29 -0000	1.160
+++ infrun.c	13 May 2004 19:25:13 -0000
@@ -2411,18 +2411,6 @@ process_event_stop_test:
       return;
     }
 
-  if (step_over_calls == STEP_OVER_UNDEBUGGABLE
-      && ecs->stop_func_name == NULL)
-    {
-      /* There is no symbol, not even a minimal symbol, corresponding
-         to the address where we just stopped.  So we just stepped
-         inside undebuggable code.  Since we want to step over this
-         kind of code, we keep going until the inferior returns from
-         the current function.  */
-      handle_step_into_function (ecs);
-      return;
-    }
-
   if (step_range_end != 1
       && (step_over_calls == STEP_OVER_UNDEBUGGABLE
 	  || step_over_calls == STEP_OVER_ALL)
@@ -2434,6 +2422,22 @@ process_event_stop_test:
 	 inferior leaves the trampoline (either by calling the handler
 	 or returning).  */
       keep_going (ecs);
+      return;
+    }
+
+  if (step_over_calls == STEP_OVER_UNDEBUGGABLE
+      && ecs->stop_func_name == NULL)
+    {
+      /* The inferior just stepped into, or returned to, an
+         undebuggable function (where there is no symbol, not even a
+         minimal symbol, corresponding to the address where the
+         inferior stopped).  Since we want to skip this kind of code,
+         we keep going until the inferior returns from this
+         function.  */
+      /* NOTE: cagney/2004-05-12: This test is performed after the
+	 sigtramp test as often sigtramps, while recognized by GDB,
+	 have no symbol information.  */
+      handle_step_into_function (ecs);
       return;
     }