calloc.c File Reference

#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

Include dependency graph for calloc.c:

Go to the source code of this file.

Macros
#define	MUL_NO_OVERFLOW   (1UL << (sizeof(size_t) * 4))

Functions
void *	calloc (size_t num, size_t size)
	Allocates memory for an array of given number objects of size and initializes all bytes in the allocated storage to zero. More...

Macro Definition Documentation

MUL_NO_OVERFLOW

#define MUL_NO_OVERFLOW   (1UL << (sizeof(size_t) * 4))

Definition at line 9 of file calloc.c.

Function Documentation

calloc()

void* calloc	(	size_t	num,
		size_t	size
	)

Allocates memory for an array of given number objects of size and initializes all bytes in the allocated storage to zero.

Allocates memory for an array of num objects of size size and initializes all bytes in the allocated storage to zero.

Parameters

num	number of objects
size	size of the array

Returns

(None)

Definition at line 11 of file calloc.c.

{
    /* num * size unsigned integer wrapping check */
    if((num >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && num > 0 && SIZE_MAX / num < size)
    {
        return NULL;
    }

    size_t total_size = num * size;
    void* ptr = malloc(total_size);

    if(ptr)
    {
        memset(ptr, 0, total_size);
    }

    return ptr;
}

References malloc(), memset(), MUL_NO_OVERFLOW, NULL, and SIZE_MAX.