malloc : cast to pointer from integer of different size [
I have this piece of code:
...
#include <stdlib.h>
...
typedef struct tToken
{
tState state; //stav lexemu
char *data; //hodnota lexemu
int row; //radek lexemu
int column; //sloupec lexemu
}tToken;
tToken token;
...
void *gcMalloc(int dataSize){
...
void *AllocatedData = (void*)malloc(dataSize);
return AllocatedData;
}
...
if(token.data == NULL)
token.data = (char *) gcMalloc( sizeof(char) ); //there is the problem
But the error
warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
is still there... Can someone please explain me why ? And how to change it ?
My guess is that the code you posted does not accurately represent the true structure of your translation unit (or units). Apparently, in reality your gcMalloc function is either defined after you make a call to it or even defined in a different translation unit.
Meanwhile, at the point of the call
token.data = (char *) gcMalloc( sizeof(char) );
the gcMalloc function is completely unknown (not declared, not defined), which makes the compiler assume that it returns int . Hence the warning about trying to cast a 32-bit int value to a 64-bit pointer of char * type.
You have to make sure your gcMalloc function is declared before you make any attempts to call it. This is what a declaration of your gcMalloc might look like
void *gcMalloc(int dataSize);
If your program consists of multiple translation units, such declarations are typically placed in header files and included at the very top of each translation units that needs them.
And get rid of the casts. None of the casts you used in your code are necessary. It looks like you added these casts in a futile attempt to suppress diagnostic messages pointing out serious problems in your code.
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