Re: rationale for eliding modifications to string constants

[Uday P. Khedker]

You got me there :-)

Yes you are right. The reason I gave for dead code elimination is not
sound! Should have thought a bit before writing :-(

Uday.

Axel Freyn wrote, On Wednesday 15 September 2010 12:05 AM:

Hello Uday,
On Tue, Sep 14, 2010 at 11:50:11PM +0530, Uday P. Khedker wrote:

[..]
The point is: in your program is is only a pointer. When you pass s
as a parameter to printf, the compiler assumes that only s is being
used so the (effective) assignment

    *s = 'H'

is deleted as dead code when optimization is enabled.

I can't believe your argumentation is correct. Wouldn't that mean:
When I have a code, where I only pass the pointer to a function like:

void f(int *);
int main(){
   int *s = (int *)malloc(100,sizeof(int));
   for(int i = 0; i<  100; ++i)
     s[i] = 0;
   f(s);
   free(s);
}

The compiler would be allowed to erase the complete for-loop? And thus
the initialization of the array?

Or I did misunderstand your argumentation...

Axel