On Wed, Jul 22, 2009 at 6:38 AM, Robert
Bradshaw<[email protected]> wrote:
> On Jul 21, 2009, at 10:47 PM, Peter Alexander wrote:
>
>> Hi all,
>>
>> I'm getting a cython build[1] error[2] from the following code
>> snippet[3].
>> A test file[4] using a similar implementation (stack memory only)
>> built fine.
>> Could you help me see what I'm doing wrong here.
>
> Cython variable semantics are just like they are in Python,
> specifically, note that you are assigning to mp_head in that function.
>
> mp_head = mp_cur
>
> This makes mp_head into a local variable (and, since you haven't
> specified a type, of type object). Just like Python, if you want to
> assign to a global variable, you need to put "global mp_head" in your
> function body.
>
> To make this error more clear, it would be a good idea to emit a
> warning that mp_head is being used before it is defined.
>
> - Robert
>
>> I'm using repo: cython-devel changeset: 2094:bcc850a1253a date: Mon
>> Jul 20 15:40:26 2009 -0700
>> Thanks ~Pete
>>
>> [1] ####### build.sh script ##########
>>
>> cython -a -I/home/travlr/src/numpy.gitsvn/doc/cython/ "$1"
>>
>> gcc -shared -pthread -fPIC -fwrapv -O2 -Wall -fno-strict-aliasing -
>> std=c99\
>> -I/usr/include/python2.6 -o ${1%\.*}.so ${1%\.*}.c
>>
>> ######## end build.sh script ########
>>
>> [2] ######## build error message ########
>>
>> $ ./build utils.pyx
>>
>> Error converting Pyrex file to C:
>> ------------------------------------------------------------
>> void* mmalloc(size_t size, size_t n_items):
>> cdef:
>> MemPoolItem* mp_cur = <MemPoolItem*>malloc(sizeof
>> (MemPoolItem))
>> mp_cur.memory = malloc(size * n_items)
>> mp_cur.next = mp_head
>> ^
>> ------------------------------------------------------------
>> /home/travlr/py/cy/utils.pyx:14:29: Cannot convert Python object to
>> 'MemPoolItem *'
>>
>> [...]
>>
>> ######## end build error message ###########
>>
>> [3] ######## code snippet #########
>>
>> from defs cimport *
>>
>> cdef:
>> struct MemPoolItem:
>> void* memory
>> MemPoolItem* next
>>
>> MemPoolItem* mp_head=NULL
>>
>> void* mmalloc(size_t size, size_t n_items):
>> cdef:
>> MemPoolItem* mp_cur = <MemPoolItem*>malloc(sizeof
>> (MemPoolItem))
>> mp_cur.memory = malloc(size * n_items)
>> mp_cur.next = mp_head
>> mp_head = mp_cur
>> return mp_cur.memory
>>
>> mfree():
>> cdef:
>> MemPoolItem* mp_cur = mpi_head
>> MemPoolItem* mp_tmp = NULL
>> while mp_cur:
>> free(mp_cur.memory)
>> mp_cur.memory = NULL
>> mp_tmp = mpi_cur.next
>> free(mpi_cur)
>> mp_cur = mpi_tmp
>> mp_head = NULL
>>
>> ######## end code snippet #########
>>
>> [4] ######## test file #########
>>
>> cdef:
>> struct S_t:
>> int val
>> S_t* next
>>
>> S_t s
>>
>> _run():
>> s.val = 345
>> print s.val
>>
>> def run():
>> _run()
>>
>> ########### end test file ############
>> _______________________________________________
>> Cython-dev mailing list
>> [email protected]
>> http://codespeak.net/mailman/listinfo/cython-dev
>
> _______________________________________________
> Cython-dev mailing list
> [email protected]
> http://codespeak.net/mailman/listinfo/cython-dev
>
Hi Robert,
I'm certainly confused by the semantics. Also, I can't find the use of
'global' documented anywhere yet.
1) I'm not sure why the "test" file built ok while referencing the
varible w/ out declaring it to be "global".
2) Placing "global mp_head" as the first line of the function body in
both functions gives a different error(s):
Thank you,
################################
$ ./build utils.pyx
Error converting Pyrex file to C:
------------------------------------------------------------
return mp_cur.memory
mfree():
global mp_head
cdef:
MemPoolItem* mp_cur = mpi_head
^
------------------------------------------------------------
/home/travlr/py/cy/utils.pyx:22:42: undeclared name not builtin: mpi_head
Error converting Pyrex file to C:
------------------------------------------------------------
MemPoolItem* mp_cur = mpi_head
MemPoolItem* mp_tmp = NULL
while mp_cur:
free(mp_cur.memory)
mp_cur.memory = NULL
mp_tmp = mpi_cur.next
^
------------------------------------------------------------
/home/travlr/py/cy/utils.pyx:27:28: undeclared name not builtin: mpi_cur
Error converting Pyrex file to C:
------------------------------------------------------------
MemPoolItem* mp_tmp = NULL
while mp_cur:
free(mp_cur.memory)
mp_cur.memory = NULL
mp_tmp = mpi_cur.next
free(mpi_cur)
^
------------------------------------------------------------
/home/travlr/py/cy/utils.pyx:28:24: undeclared name not builtin: mpi_cur
Error converting Pyrex file to C:
------------------------------------------------------------
while mp_cur:
free(mp_cur.memory)
mp_cur.memory = NULL
mp_tmp = mpi_cur.next
free(mpi_cur)
mp_cur = mpi_tmp
^
------------------------------------------------------------
_______________________________________________
Cython-dev mailing list
[email protected]
http://codespeak.net/mailman/listinfo/cython-dev
