[splint-discuss] How to check Uninitialized variable

[Ian Moor]

Vijayendra Suman wrote:
> Hello All,
> 
> Thanks for the prompt response,
> 
> Here is the small piece of code this is compilable
> 
>   1 #include <stdio.h>
>   2 void Call(int *a)
>   3 {
>   4         int StatusUpdate;
>   5         int MyOne()
>   6         {
>   7                 printf("One \n");
>   8                 return 1;
>   9         }
>  10         int MyTwo()
>  11         {
>  12                 printf("Two \n");
>  13                 return 2;
>  14         }
>  15         if (a==NULL) return;
>  16         if (*a == 1 )
>  17                 StatusUpdate = MyOne();
>  18         else
>  19                 StatusUpdate = MyTwo();
>  20 }
>  21
>  22 int main(int argc, char * argv[])
>  23 {
>  24  int call; /* call is not initialized */
>  25   Call(&call);
>  26    return 0;
>  27 }
> 
> I compiled using
> gcc -o my my.c -Wall
> 
> Problem definition:
> int call; /* call is not initialized */
> The call variable is not initialized, Even with -Wall i do not get any 
> warnings.
> 
In the gcc manual the section about the -Wuninitialized option
it says:
These warnings are possible only in optimizing compilation, because they 
require data flow information that is computed only when optimizing. If 
you do not specify -O, you will not get these warnings.

So gcc can be made to report uninitialized variables.