Problems with GNAT

Problems with GNAT

[Tim]

I have been writing bits of Ada code on a UNIX system. 
I have developed a package of utilities for sound generation. 

Upon trying to run a driver program (packtest.adb) I had written to 
exercise this package of facilities I kept getting a constraint error. 

In attempting to locate this bug I used gdb. 
Which eventually came up with:-
(gdb) step
__gnat_raise_constraint_error () at a-raise.c:154
a-raise.c:154: No such file or directory.
Current language:  auto; currently c
(gdb) where
#0  __gnat_raise_constraint_error () at a-raise.c:154
#1  0x13bd8 in packtest () at packtest.adb:64
#2  0x236c in main (argc=1, argv=0xeffff97c) at b_packtest.c:35

Does anybody know what is going on here? 
I had gdb running fine with Ada as the language and 
then it hits this error and goes phut. 
Any suggestions?
Thanks in anticipation
Tim

Re: Problems with GNAT

[Kevin J. Weise]

Tim  <blandtg@dcs.gla.ac.uk> wrote (with deletions):
>I have been writing bits of Ada code on a UNIX system. 
>I have developed a package of utilities for sound generation. 
>
>Upon trying to run a driver program (packtest.adb) I had written to 
>exercise this package of facilities I kept getting a constraint error. 
>
>In attempting to locate this bug I used gdb. 
>Which eventually came up with:-
>(gdb) step
>__gnat_raise_constraint_error () at a-raise.c:154
>a-raise.c:154: No such file or directory.
>Current language:  auto; currently c
>(gdb) where
>#0  __gnat_raise_constraint_error () at a-raise.c:154
>#1  0x13bd8 in packtest () at packtest.adb:64
>#2  0x236c in main (argc=1, argv=0xeffff97c) at b_packtest.c:35
>
>Does anybody know what is going on here? 

I'm guessing here, since you didn't (maybe couldn't?) post your source 
code.  But it looks to me like something in line 64 of packtest.adb 
raised a Constraint_Error.

Perhaps if you put in breakpoints before line 64 and query for values 
of different variables you can find one out of range.  I would look for 
boundary condition problems (e.g., attempts to reference close to the 
beginning or end of an array, such that some index attempts to 
reference a non-existant array element.

Beyond this, without more information, I don't see that we can help you 
very much.

---------------------------------------------------------------
Kevin J. Weise            email:  kweise@sed.redstone.army.mil
COSLA Corporation         voice:  (205) 842-9083
Huntsville, AL

.. standard disclaimers apply

Re: Problems with GNAT

[Robert Dewar]

Tim  <blandtg@dcs.gla.ac.uk> wrote (with deletions):

   I have been writing bits of Ada code on a UNIX system.
   I have developed a package of utilities for sound generation.
   
   Upon trying to run a driver program (packtest.adb) I had written to
   exercise this package of facilities I kept getting a constraint error.
   
   In attempting to locate this bug I used gdb.
   Which eventually came up with:-
   (gdb) step
   __gnat_raise_constraint_error () at a-raise.c:154
   a-raise.c:154: No such file or directory.
   Current language:  auto; currently c
   (gdb) where
   #0  __gnat_raise_constraint_error () at a-raise.c:154
   #1  0x13bd8 in packtest () at packtest.adb:64
   #2  0x236c in main (argc=1, argv=0xeffff97c) at b_packtest.c:35
   
   Does anybody know what is going on here?

This clearly shows you are getting a constraint error at packtest.adb:64.

If you think this constraint error is not a legitimate consequence of
your program, then narrow down the example as much as possible, and
send it along to report@gnat.com.

Re: Problems with GNAT

[Robert Dewar]

Tim says

"then it hits this error and goes phut."

"goes phut" is not exactly a precise description of the behavior
you saw ...