Recent changes to tickets

#34 problems getting the clips iOS download to start the interpreter

Gary Riley — Fri, 21 Nov 2025 00:03:24 -0000

status: reopened --> closed
assigned_to: Gary Riley

#76 CLIPS crashes when global variable modified

Gary Riley — Thu, 20 Nov 2025 23:55:52 -0000

status: new --> closed
assigned_to: Gary Riley

#76 CLIPS crashes when global variable modified

xyando — Wed, 24 Jul 2024 14:49:32 -0000

It all works fine. Thanks.

#76 CLIPS crashes when global variable modified

Gary Riley — Mon, 22 Jul 2024 03:49:44 -0000

I checked in a fix. I forgot to test the original issue. There are multiple ways to generate a bug with this issue and just modifying QSetDefglobalValue won't fix all of them. Here's an example which globalbind-3.patch will still generate an error:

(defglobal ?*foo* = (create$ 0.0))

(deffunction test (?foo)
   (bind ?*foo* ?foo)
   (println ?foo)
   (bind ?*foo* (create$ 3.0))
   (println ?foo))
(test ?*foo*)

What I did to resolve the issue is modify the routines which return the value of the global variable to return a copy of the multifield value instead of the value stored directly in the global. This preserves the multifield until garbage collection kicks in at the appropriate time.

#76 CLIPS crashes when global variable modified

xyando — Sun, 21 Jul 2024 13:05:27 -0000

Thanks Gary,
The endless looping is resolved. But the globalbind.bat fails again.

I think the equality checking once you have added is still necessary
(but after NormalizeMultifield(), but before displaying watch info)
to avoid premature release.

#76 CLIPS crashes when global variable modified

Gary Riley — Wed, 17 Jul 2024 22:05:47 -0000

Nice catch. I checked in an update.

#76 CLIPS crashes when global variable modified

xyando — Wed, 17 Jul 2024 14:29:45 -0000

Thanks Gary,
but I think an additional modification is necessary(see attached patch)
because the following program results an endless looping.

(defglobal ?*x* = (create$ 1 2 3))
(deffunction test()
  (while TRUE do
    (bind ?*x* (rest$ ?*x*))
    (printout t ?*x* crlf)
    (if (= (length$ ?*x*) 0) then
      (break)
    )
  )
)

#76 CLIPS crashes when global variable modified

Gary Riley — Tue, 16 Jul 2024 17:27:26 -0000

A fix has been checked into the svn repository. The issue occurs when setting the current value of a defglobal to its current value. This can cause the value to be prematurely released. The bug can occur outside the body of a deffunction, so the proposed patch won't fix the issue for all cases.

         CLIPS (6.4.1 4/8/23)
CLIPS> (defglobal ?*foo*  = (create$  0.0))
CLIPS> 
(loop-for-count 1 do
   (bind ?*foo* ?*foo*))
[ARGACCES2] Function 'loop-for-count' expected argument #3 to be of type integer, float, symbol, string, instance name, instance address, fact address, external address, or multifield.
FALSE
CLIPS>

#76 CLIPS crashes when global variable modified

xyando — Sun, 14 Jul 2024 17:24:57 -0000

The revised patch is attached because the elder patch fails CLIPS test_suite.

#76 CLIPS crashes when global variable modified

xyando — Sat, 13 Jul 2024 14:14:45 -0000

The posted comment is erroneous because the asterisks are missing.
Please refer the attached file.