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cfreecalloc

Abort (core dumped) when freeing array created with calloc

This

#include <stdlib.h> // test.c

int main()
{
    double *arr = (double*) calloc(1000, sizeof(arr));
    for (int i = 0; i < 1000; i++)
        arr[i] = 1; 
    free(arr);
    return 0;
}

compiled as

gcc test.c -std=c99 -o test

produces the output Aborted (core dumped) when run on Cygwin as ./test.exe.

The program exits fine when I declare int *arr (even while keeping the (double *) cast), or when I update arr[0] instead of arr[i]. What gives?

Solution

  • Change

    double *arr = (double*) calloc(1000, sizeof(arr));

    to

    double *arr = (double*) calloc(1000, sizeof(double));

    UPDATE:

    sizeof(double) and sizeof(pointer) depends on architecture. In your case they are different.