CODEWITHSUNDEEP
c
nineties
nineties

Reputation: 433

C function prototype, compile error

C newbie here. Trying to figure out the error in my program.

Function prototype:

float* convolve(int (*)[10], int (*)[3], int *, int);

actual function:

float* convolve(int* ImdataPtr, int* KernelPtr, int* size, int sizeKernel)

How it's called in main:

float* output;
output = convolve(input,kernel,sizeIm,3);

Compile Error:

program.c:55:8: error: conflicting types for ‘convolve’

Help, please...

Upvotes: 0

Views: 164

Answers (2)

Sagar
Sagar

Reputation: 9503

Your prototype specifies, for its first and second arguments, pointer to an array of integers , whereas in your function, you are specifying integer pointers alone.

You need to either correct your prototype, or your function definition.

Upvotes: 1

Brendan Long
Brendan Long

Reputation: 54242

The problem is that the prototype doesn't match. Make sure the types are exactly the same, since int(*)[10] and int(*)[3] are different types than int*:

float* convolve(int(*)[10], int(*)[3], int*, int);

float* convolve(int (*ImdataPtr)[10], int (*KernelPtr)[3], int* size, int sizeKernel) {
    // etc
}

You can (and probably should) even make them exactly the same, including argument names:

float* convolve(int (*ImdataPtr)[10], int (*KernelPtr)[3], int* size, int sizeKernel);

float* convolve(int (*ImdataPtr)[10], int (*KernelPtr)[3], int* size, int sizeKernel) {
    // etc
}

I had to look up how to declare these, so you might find the question on C pointer to array/array of pointers disambiguation useful too. int*[3] is an array of pointers to int (just read it backwards), but int(*)[3] is a pointer to an array of int.

Upvotes: 6

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