It seems to me like the error message is correct. The first argument to
ccall must be constant, and it looks like you have a variable called `path`
in your ccall.
Can you try to declare path as const, or just put the library name/path as
a string/symbol in the ccall expression.
Ivar
kl. 20:10:32 UTC+1 mandag 10. mars 2014 skrev Patrick Foley følgende:
>
> I have changed the function to now be
> "extern double bessela1(double x) { "
>
> Everything still compiles nicely, but I get the same error.
>
> - Patrick
>
>
> On Monday, March 10, 2014 2:45:12 PM UTC-4, Patrick Foley wrote:
>>
>> Hi All,
>>
>> I wrote some C code to compute a ratio of bessel functions, and am now
>> trying to access it with Julia. I have compiled it into a shared library
>> with
>>
>> "gcc -std=c99 -fPIC -shared -lm bessela1.c -o bessela1.so".
>>
>> This compiles without any errors or warnings, and the code works.
>>
>>
>> I'm trying to use a function
>> '''
>>
>> double bessela1(double x) {
>>
>> // lots of code.
>>
>> return y;
>>
>> }
>> ''' defined within the bessela1.c file. All functions it needs are also
>> in the .c file, and I don't use any other files.
>>
>> So in my Julia code, I have
>>
>> s = ccall( (:bessela1, path), Float64, (Float64, ), 0.5)
>> and path is the path to the bessela1.so file.
>>
>> When I run this in julia, I get the following error:
>>
>> ERROR: type: anonymous: in ccall: first argument not a pointer or valid
>> constant expression, expected DataType, got Type{(Any...,)}
>>
>> in anonymous at no file
>>
>>
>> I believe that the C code is compiling correctly (I know it works in C),
>> and I can run dlopen() on the .so file and get a pointer back, but I'm not
>> sure what to do with that.
>>
>> Can anyone point out what I'm doing incorrectly? I've also tried using
>> "bessela1" rather than :bessela1, but get the same error.
>>
>> Thanks,
>> Patrick
>>
>
