From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tom Tromey <tromey@cygnus.com>
To: spolk@redhat.com
Cc: Insight List <insight@sourceware.cygnus.com>
Subject: Re: Patch: fixlet in gdbtk-cmds.c
Date: Wed, 29 Nov 2000 13:48:00 -0000
Message-id: <87k89mzbix.fsf@creche.cygnus.com>
References: <4.2.0.58.20001128125809.01a7f100@pop.cygnus.com> <87wvdn4krn.fsf@creche.cygnus.com> <3A245282.C01BFEE6@redhat.com>
X-SW-Source: 2000-q4/msg00324.html

Syd> I would rather have a global variable for whether a gdbtk command
Syd> generated the error as opposed to Tcl itself rather than messing
Syd> with interp result flags. This is just asking to break when the
Syd> interp data structure is changed.

I looked at this a bit more.

In the code I quoted `result_ptr' is a global variable like that.
This isn't the intepreter or the result.

I think this patch does what I want:

2000-11-29  Tom Tromey  <tromey@cygnus.com>

	* gdbtk-cmds.c (call_wrapper): Don't reset result if wrapped
	command returned error.

Unfortunately, it is unclear what negative ramifications, if any, this
patch might have.  I'd have to consider it "dangerous".

Syd> I will examine this more in a couple of weeks.

I won't be working on Insight at that point.

Tom

Index: gdbtk-cmds.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbtk/generic/gdbtk-cmds.c,v
retrieving revision 1.12
diff -u -r1.12 gdbtk-cmds.c
--- gdbtk-cmds.c	2000/07/25 20:41:07	1.12
+++ gdbtk-cmds.c	2000/11/29 21:46:36
@@ -459,6 +485,7 @@
 {
   struct wrapped_call_args wrapped_args;
   gdbtk_result new_result, *old_result_ptr;
+  int wrapped_returned_error = 0;
 
   old_result_ptr = result_ptr;
   result_ptr = &new_result;
@@ -497,16 +524,24 @@
       Tcl_Eval (interp, "gdbtk_tcl_idle");
 
     }
+  else
+    {
+      /* If the wrapped call returned an error directly, then we don't
+	 want to reset the result.  */
+      wrapped_returned_error = wrapped_args.val == TCL_ERROR;
+    }
 
   /* do not suppress any errors -- a remote target could have errored */
   load_in_progress = 0;
 
   /*
-   * Now copy the result over to the true Tcl result.  If GDBTK_TO_RESULT flag
-   * bit is set , this just copies a null object over to the Tcl result, 
-   * which is fine because we should reset the result in this case anyway.
+   * Now copy the result over to the true Tcl result.  If
+   * GDBTK_TO_RESULT flag bit is set, this just copies a null object
+   * over to the Tcl result, which is fine because we should reset the
+   * result in this case anyway.  If the wrapped command returned an
+   * error, then we assume that the result is already set correctly.
    */
-  if (result_ptr->flags & GDBTK_IN_TCL_RESULT)
+  if ((result_ptr->flags & GDBTK_IN_TCL_RESULT) || wrapped_returned_error)
     {
       Tcl_DecrRefCount (result_ptr->obj_ptr);
     }
@@ -580,8 +615,10 @@
      Tcl_Obj *CONST objv[];
 {
   if (objc != 1)
-    Tcl_SetStringObj (result_ptr->obj_ptr,
-		      "Wrong number of args, none are allowed.", -1);
+    {
+      Tcl_WrongNumArgs (interp, 1, objv, NULL);
+      return TCL_ERROR;
+    }
 
   if (inferior_pid != 0 && target_has_execution)
     {