Illegal execution error message

[Ed Holley]

What that message generally means is that your program has done a
call to address 0.  The debugger cannot figure out how you got
there, because the information about the stack frame is unavailable.

What you need to do is to find out where your program is making the jump
to address 0, either by hand stepping through your program,
or by turning the dbx trace command on.  The second method is less work
for you, but is very slow.

In article <1991Apr9.134802.26440 at eagle.lerc.nasa.gov>, fsfrick at bones
(David Fricker) writes:
> I'm porting a local graphics program which uses the GL calls, and I
> get the error message 'illegal execution' when it bombs.  The program
> is a scientific plotting/graphics package (3d, contours, etc.) which 
> compiles nicely (now), starts up okay, but bombs when asked to do
> graphics.
> 
> I tried running 'xde' to track down the offending call, but the following
> is all I get from the debugger:
> 
> 	Unreadable instruction at address 0x0
> 	warning: could not locate trace table from starting address 0x0
> 	Could not determine current function
> 

----------------------------------------------------------------
Ed Holley	IBM AWD
ibm net:	ed at bee.austin.ibm.com
vnet:		holley at austin
internet:	eholley at wombat.austin.ibm.com
uucp:		...!cs.utexas.edu!ibmchs!auschs!bee.austin.ibm.com!ed