2000-02-23 Fernando Nasser <fnasser@cygnus.com>

        * infcmd.c (run_stack_dummy): Do not pop frame on random signal.
        * valops.c (_initialize_valops): Add command "set unwindonsignal".
        (hand_function_call): Test for unwind_on_signal and act accordingly.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 81fdc39d893a9ad4dce2e0bf3546e7a53b052c6b..c861278f2016784348e1f589fe14235dbc1d246e 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2000-02-23  Fernando Nasser  <fnasser@cygnus.com>
+
+       * infcmd.c (run_stack_dummy): Do not pop frame on random signal.
+       * valops.c (_initialize_valops): Add command "set unwindonsignal".
+       (hand_function_call): Test for unwind_on_signal and act accordingly.
+
 Wed Feb 23 12:58:46 2000  Andrew Cagney  <cagney@b1.cygnus.com>
 
        * gdbarch.sh (dis_asm_read_memory): Change LEN to unsigned long.

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index fb439849ea6774d59bbfea061b2f7072e80e26e8..84bc9204bbf455e7e0abbc2da864e63a63f54ad0 100644 (file)
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -926,20 +926,12 @@ run_stack_dummy (addr, buffer)
 
   discard_cleanups (old_cleanups);
 
+  /* We can stop during an inferior call because a signal is received. */
   if (stopped_by_random_signal)
-    {
-      /* If the inferior execution fails we need to restore our
-         stack.  It is not done by proceed() in this case. */
-      /* Pop the empty frame that contains the stack dummy.
-         POP_FRAME ends with a setting of the current frame, so we
-         can use that next. */
-      POP_FRAME;
-      return 1;
-    }
+    return 1;
     
   /* We may also stop prematurely because we hit a breakpoint in the
-     called routine.  We do not pop the frame as the user may wish
-     to single step or continue from there. */
+     called routine. */
   if (!stop_stack_dummy)
     return 2;
 

diff --git a/gdb/valops.c b/gdb/valops.c
index 5fd0fd8c1edc62b57c1765fd44e62b5c37b6d7d2..5dc6b1e7fe7ef48834af70d95da64783cde7ad07 100644 (file)
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -75,6 +75,13 @@ static int auto_abandon = 0;
 #endif
 
 int overload_resolution = 0;
+
+/* This boolean tells what gdb should do if a signal is received while in
+   a function called from gdb (call dummy).  If set, gdb unwinds the stack
+   and restore the context to what as it was before the call.
+   The default is to stop in the frame where the signal was received. */
+
+int unwind_on_signal_p = 0;
 \f
 
 
@@ -1726,16 +1733,42 @@ You must use a pointer to function type variable. Command ignored.", arg_name);
        /* We stopped inside the FUNCTION because of a random signal.
           Further execution of the FUNCTION is not allowed. */
 
-       /* In this case, we must do the cleanups because we don't
-          want the dummy anymore (the dummy frame has been poped already. */
-       do_cleanups (old_chain);
+        if (unwind_on_signal_p)
+         {
+           /* The user wants the context restored. */
 
-       /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
-          a C++ name with arguments and stuff.  */
-       error ("\
-The program being debugged stopped while in a function called from GDB.\n\
+            /* We must get back to the frame we were before the dummy call. */
+            POP_FRAME;
+
+           /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
+              a C++ name with arguments and stuff.  */
+           error ("\
+The program being debugged was signaled while in a function called from GDB.\n\
+GDB has restored the context to what it was before the call.\n\
+To change this behavior use \"set unwindonsignal off\"\n\
 Evaluation of the expression containing the function (%s) will be abandoned.",
-              name);
+                  name);
+         }
+       else
+         {
+           /* The user wants to stay in the frame where we stopped (default).*/
+
+           /* If we did the cleanups, we would print a spurious error
+              message (Unable to restore previously selected frame),
+              would write the registers from the inf_status (which is
+              wrong), and would do other wrong things.  */
+           discard_cleanups (old_chain);
+           discard_inferior_status (inf_status);
+
+           /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
+              a C++ name with arguments and stuff.  */
+           error ("\
+The program being debugged was signaled while in a function called from GDB.\n\
+GDB remains in the frame where the signal was received.\n\
+To change this behavior use \"set unwindonsignal on\"\n\
+Evaluation of the expression containing the function (%s) will be abandoned.",
+                  name);
+         }
       }
 
     if (rc == 2)
@@ -3562,4 +3595,13 @@ _initialize_valops ()
      &showlist);
   overload_resolution = 1;
 
+  add_show_from_set (
+  add_set_cmd ("unwindonsignal", no_class, var_boolean,
+              (char *) &unwind_on_signal_p,
+"Set unwinding of stack if a signal is received while in a call dummy.\n\
+The unwindonsignal lets the user determine what gdb should do if a signal\n\
+is received while in a function called from gdb (call dummy).  If set, gdb\n\
+unwinds the stack and restore the context to what as it was before the call.\n\
+The default is to stop in the frame where the signal was received.", &setlist),
+                    &showlist);
 }