SYSTEM-F-ACCVIO error during BASIC compile

[Brad Olson]

Help! I'm getting a SYSTEM-F-ACCVIO error when attempting to compile a Compaq BASIC program (BASIC v1.5, Alpha 4100, VMS v7.3-1) using the command $B/LIST/NOCROSS/OPTIMIZE=LEVEL=4/LINE. The same program successfully compiles on a MicroVAX 3100-40 (BASIC v3.9, VMS v6.2). Here are some abridged details:

%SYSTEM-F-ACCVIO, access violation, reason mask=00, virtual address=00000000020B

%TRACE-F-TRACEBACK, symbolic stack dump follows
image module routine
BASIC ALCGEM ALC_GEMUTL_NAME_CREATE
BASIC ALCGEM ALC_GEMUTL_GENERIC_ROUTINE
BASIC ALCGEM ALC_GEM_ROUTINE
BASIC ALCPRC ALC_PROCEDURE
BASIC ALCDRV ALLOC
BASIC CGNDRIVER CGNDRIVER
BASIC BASTARTUP ENV_ENTER_BASIC_COMPILER
BASIC GEM_CP_VMS GEM_CP_MAIN

Any help would be greatly appreciated. Thanks!

[Lokesh_2]

Hi,

I do not know if you have already check the online help. In not, then here it is:

Thanks & regards,
Lokesh

*********************************

ACCVIO, access violation, reason mask='xx', virtual
address='location', PC='location', PSL='xxxxxxxx'

Facility: SYSTEM, System Services

Explanation: An image attempted to read from or write to a memory location
that is protected from the current mode. This message
indicates an exception condition and is followed by a register
and stack dump to help locate the error. The reason mask is
a longword whose lowest 5 bits, if set, indicate that the
instruction caused a length violation (bit 0), referenced the
process page table (bit 1), attempted a read/modify operation
(bit 2), was a vector operation on an improperly aligned
vector element (bit 3), or was a vector instruction reference
to an I/O space address (bit 4).

This message is also displayed when an attempt has been made
to make the user stack larger than the user's virtual address
space permits. For example, the automatic user stack expansion
algorithm reports an access violation with the following
two conditions (which should serve as hints that automatic
expansion has failed):

o The reason mask has the low-order bit set. This indicates a
memory reference that is not described in any page table.

o The relatively small P1 address space virtual address is
referenced.


User Action: Examine the PC and virtual address displayed in the message.
The virtual address is often the address to which the access
attempt was made. However, in the case of vector-related
access violations and in some processor implementations, the
reported virtual address may be some other address in the same
page as that address to which the access was attempted. Check
the program listing to verify that instruction operands or
procedure call arguments are correct.

If this message is displayed because of insufficient virtual
memory for automatic user stack expansion, reduce the user
stack requirements of the image or increase the virtual
address space available to the process in which the image
is executed.

[Martin P.J. Zinser]

Hello,

first try would be to simplify the compile command (esp the /opt). If that helps you do have a workaround ;-)
Else try to cut down the code until you have localized the problem in a short example code. Then it is time to pick-up the phone and log a call with support.

Greetings, Martin

[Antoniov.]

Hi Brad,
follow hints of Martin: it's the best way.
Looking for BASIC in VMS ASK Wizard you can find a lot of ACCVIO related basic compiler.
Here there are a few:
http://h71000.www7.hp.com/wizard/wiz_9027.html
http://h71000.www7.hp.com/wizard/wiz_9028.html
http://h71000.www7.hp.com/wizard/wiz_6658.html
It seems basic compiler is unstable product.
Bye
Antoniov

[John Gillings · Accepted solution]

Brad,

An ACCVIO from any compiler, or other layered product is, by definition, a bug and should be fixed.

A quick search, based on the information you've posted does not reveal any matches with known issues, and there are no current publically released patches for your compiler.

To resolve this issue will require a report to engineering, containing a complete reproducer. Either your whole program, or a cut down version that demonstrates the problem.

Forums like this, and "Ask The Wizard" are not suitable for dealing with this type of problem. Please log a case against your support contract with your local CSC to have it dealt with properly.

[Willem Grooters]

Please log a case against your support contract with your local CSC to have it dealt with properly.


John, what if you don't have a support contract? The only source you have then are these forums.