On: GCC null pointer check removed

[mjevans]

Again: There really needs to be a warning (elevate-able to an error like usual) for all removed / "optimized out" code. A programmer added it for a reason, and either that reason is invalid and it can be removed OR the compiler's doing something the programmer did not intend and is thus exhibiting undesired behavior.

[ogoffart → mjevans]

This is not possible.

   void foo(int x) {
       if (x)  do_something();
       else do_something_else();
   }

   void fn1() { foo(0); }
   void fn2() { foo(1); }

When the code is inlined, the compiler can propagate constant and optimize the `if`. Do you really expect two warnings there?

These warning would happen all the time.

And anyway, this does not apply to this particular bug which is just a compiler bug (which has been fixed). The warning was there all along:

    This is free software; see the source for copying conditions.  There is NO
    warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[saagarjha → mjevans]

So you’re looking for a warning that will always show up in any non-trivial program?

[tinus_hn → mjevans]

This is a bug, not optimization.