hramrach

Has anybody actually read the article?

Meta is not arguing against adding the leap second, they just argue that skewing the clock slightly over some hours avoids the 'invalid' time with 61 seconds in a minute and the resulting software problems while keeping the time reasonably accurate for for the general public and computer systems.

Isn't it the same in the countries that are looked down at because they have the 'overt' type of corruption?

It's just the way things are done there, and it's so entrenched that people cannot step back and see it rationally. Unless they are, say, from a country where the corruption has taken on a different form, or from Mars.

I believe it completely solves the question

? May we remove '*p = 0;', whether we remove the malloc+free or not?

Sure, it does not solve the question when arbitrarily removing NULL pointer checks is OK.

It is true that when the compiler is inlining code or expanding a macro it may have a NULL check that is spurious in environments that do not map page 0 based on the observation that the pointer was dereferenced previously.

And this assumption is incorrect in environments that do map page 0 causing wrong code generation.

I don't understand.

If you can turn the loop from upward to downward then you do have a bound for it, and then you can tell if it overflows or not.

Also why is signed overflow a problem and not unsigned?

Surely you want unsigned loop optimized also?

Don't compilers already have ways to mark variables and dereferences in a way to say 'I really want access to this value happen'?

They are free to optimize away access to any result that is not used based on code elimination, and these annotations limit what can be eliminated.

However, basing code elimination on UB, as pointed out earlier, would basically eliminate all code if you were rigorous enough because you basically cannot eliminate UB in C code, which is not in any way useful.