>> if it was smart it would have figured out that the value never was initialized
> But that's false
Are you reading the same code the rest of us are? NeverCalled is never called. So Do is not explicitly initialized and therefore contains a null pointer because it's a static variable.
Now compiler writers wanted their benchmark scores better so instead of crashing the program when Do is called, which happens in the unoptimized version, they decided to play fast and loose with UB. They just made code vanish.
What I'm saying is that if the compiler can figure out that NeverCalled is actually called from somewhere then it's free to make these optimizations. But if it knows it's not called then it should either disable the optimization for that statement or better yet give a warning.
> There's nothing stopping this from being linked into a binary which doesn't even call main, or which calls NeverCalled, etc.
Which is why I called for Whole Program Optimization to solve that issue. Since it looks like you did not bother to find out what that is and how it would solve that issue I'll explain it here. In Whole Program Optimization the compile is pushed down to the link phase. This lets the compiler see the who program and apply optimizations globally instead of at a file by file bases. So it can tell if main is never called or if NeverCalled is called or not.
> And I bet you will also insist stamping your feet
Now you're attacking me instead of my arguments. Do you wish to have a civilized discussion or just resort to insults? Because if it's the latter I will just ignore you in the future.
> which just goes to show that the compiler writers know way more about this than you do
> You know nothing, but you're convinced you know so much more than those stupid compiler writers.
I am a compiler writer so I do know what I'm talking about. It's a small personal project but it means I've been doing a lot of thinking and research about compilers. And eliminating UB is my current design focus.
And if you reread what I wrote you can see I never called them stupid. They are quite smart and know what they are doing. But even a smart person can make bad decisions depending on their motivations. What I'm saying is that they are putting their skill towards exploiting UB instead of protecting programmers from it.
Just wanted to say, I think your comments here are useful. Given some of the replies, I guess the person who said that this is "literally a religious issue" is right. Sigh!
Thanks. I'm glad some people are getting some use from my posts.
I'm used to the "religious" attacks against me as this isn't the first time it's happened. You need to have a thick skin to post the non-mainstream ideas here. It doesn't matter if you are correct or that your idea is technically accurate, it's all about the how popular the other view is.
The funny thing is how consistent the pattern is. First you see the downvotes and upvotes come in. This is the first sign you're on a hot button topic. Then people will simply tell you that you're wrong without any counter argument. Once you respond back with further facts to back up your argument the attacks on your education/skill/knowledge come in. You misused some cargo cult terminology and that's proof you don't know what you're talking about. Usually it ends there but once in a while someone starts up with the personal insults.
It's funny and sad watching the same thing happen over and over. Sigh.
> But that's false
Are you reading the same code the rest of us are? NeverCalled is never called. So Do is not explicitly initialized and therefore contains a null pointer because it's a static variable.
Now compiler writers wanted their benchmark scores better so instead of crashing the program when Do is called, which happens in the unoptimized version, they decided to play fast and loose with UB. They just made code vanish.
What I'm saying is that if the compiler can figure out that NeverCalled is actually called from somewhere then it's free to make these optimizations. But if it knows it's not called then it should either disable the optimization for that statement or better yet give a warning.
> There's nothing stopping this from being linked into a binary which doesn't even call main, or which calls NeverCalled, etc.
Which is why I called for Whole Program Optimization to solve that issue. Since it looks like you did not bother to find out what that is and how it would solve that issue I'll explain it here. In Whole Program Optimization the compile is pushed down to the link phase. This lets the compiler see the who program and apply optimizations globally instead of at a file by file bases. So it can tell if main is never called or if NeverCalled is called or not.
> And I bet you will also insist stamping your feet
Now you're attacking me instead of my arguments. Do you wish to have a civilized discussion or just resort to insults? Because if it's the latter I will just ignore you in the future.
> which just goes to show that the compiler writers know way more about this than you do
> You know nothing, but you're convinced you know so much more than those stupid compiler writers.
I am a compiler writer so I do know what I'm talking about. It's a small personal project but it means I've been doing a lot of thinking and research about compilers. And eliminating UB is my current design focus.
And if you reread what I wrote you can see I never called them stupid. They are quite smart and know what they are doing. But even a smart person can make bad decisions depending on their motivations. What I'm saying is that they are putting their skill towards exploiting UB instead of protecting programmers from it.