Re: crash in guile-sqlite3

[Daniel Krueger]

Oh, I'm sorry, I missed the fact that all bits in the pointer would be
set. Correct would be this:

(make-pointer (bit-extract (lognot 0) 0 (* 8 (sizeof '*))))

So, okay, this may not be a better solution :D

- Daniel

On Tue, May 1, 2012 at 5:05 PM, Daniel Krueger <address@hidden> wrote:
> Hi,
>
> I just wanted to note that it should work just to use (make-pointer #xff).
>
> - Daniel
>
> On Tue, May 1, 2012 at 5:01 PM, Joonas Sarajärvi <address@hidden> wrote:
>> 2012/5/1 Joonas Sarajärvi <address@hidden>:
>>
>>> However, thank you for taking a look at the problem. The change you
>>> placed at 
>>> git://gitorious.org/~sunjoong/guile-sqlite3/sunjoongs-guile-sqlite3.git
>>> seems to completely resolve the crash for me.
>>>
>>> -Joonas
>>
>> Replying to myself, I now noticed that the change will not work in a
>> 64-bit computer. My impression is that this is due to the fact that
>> the 5th parameter taken by sqlite3_bind_text function is really a
>> pointer and not an int. On amd64 computers, int are 4 bytes wide while
>> pointers are 8 bytes.
>>
>> I also think that the older way of passing SQLITE_TRANSIENT as a
>> pointer should work. However, there was a small bug in the code that
>> constructed the pointer. I made a yet-another clone of the main
>> guile-sqlite3 repository and pushed a change that I think fixes this.
>> The change I did is also here:
>>
>> diff --git a/sqlite3.scm b/sqlite3.scm
>> index fcc1fdf..5047e71 100644
>> --- a/sqlite3.scm
>> +++ b/sqlite3.scm
>> @@ -301,8 +301,9 @@
>>                     int
>>                     (dynamic-func "sqlite3_bind_null" libsqlite3)
>>                     (list '* int)))
>> -        (sqlite-transient (bytevector->pointer
>> -                           (make-bytevector (sizeof '*) #xff))))
>> +        (sqlite-transient (dereference-pointer
>> +                           (bytevector->pointer
>> +                            (make-bytevector (sizeof '*) #xff)))))
>>     (lambda (stmt key val)
>>       (assert-live-stmt! stmt)
>>       (let ((idx (key->index stmt key))
>>
>>
>> The test case by Sunjoong Lee is also cherry-picked to the git branch
>> I placed on gitorious. Hopefully it was acceptable to include it.
>> Should I make a merge request of this?
>>
>> -Joonas
>>