How to use maloc with strcut

[Mateusz_madi]

I have program:
--------------
#include<stdio.h>
struct s{
int x;
struct s* nxt;
};

void f(struct s* pt)
{
malloc(sizeof(struct s));
}
.....
Why i get warrning when i'am trying to compile it sth like:
Incompatible implicit declaration of build-in function 'malloc'
??

 

[Seebs]

I have program:
--------------
#include<stdio.h>
struct s{
int x;
struct s* nxt;
};

void f(struct s* pt)
{
malloc(sizeof(struct s));
}
....
Why i get warrning when i'am trying to compile it sth like:
Incompatible implicit declaration of build-in function 'malloc'
??

This has nothing to do with the struct, and everything to do with the fact
that you called malloc(), but you never included <stdlib.h>, so it hasn't
been declared. The compiler knows about malloc, though.

In C89, if you used a function without a declaration, it was assumed to return
int. malloc() doesn't return int, and the compiler is warning you that
this probably means something has gone wrong. Which it has.

-s

 

[Mateusz_madi]

This has nothing to do with the struct, and everything to do with the fact
that you called malloc(), but you never included <stdlib.h>, so it hasn't
been declared.  The compiler knows about malloc, though.

In C89, if you used a function without a declaration, it was assumed to return
int.  malloc() doesn't return int, and the compiler is warning you that
this probably means something has gone wrong.  Which it has.

-s

Thank's seebs