bad_alloc & unreachable code

Answered

Permanently deleted user

Created February 06, 2018 15:32

Greetings:

In the following code:

try {
    auto ptr = new MyClass();
    // ...
} catch (std::bad_alloc &) {
    // ...
}

The 'catch' block is marked as unreachable code in Clion. Without disabling the code inspection rule, is there a way for Clion to recognized that 'new' operator may throw a std::bad_alloc and thus, the catch block is potentially reachable?

Thanks,

J-F

7 comments

Anna Falevskaya

Created February 07, 2018 10:43

Hi! Unfortunately, I can't reproduce the issue on my side:

What OS, CLion version and compiler do you use?

Permanently deleted user

Created February 07, 2018 11:23

Hey Anna,

Thanks for replying. I noticed that the warning only shows up if there's a return statement in the try block. For example:

Omitting the return statement does not issue the unreachable code warning.

So it turns out that Clion is assuming that the return will always execute, even if a std::bad_alloc exception may be thrown.

J-F

Anna Falevskaya

Created February 07, 2018 11:45

Thanks a lot for the details! We have a related issue in our tracker: https://youtrack.jetbrains.com/issue/CPP-3094. And it was fixed in the CLion 2018.1 EAP, please try it. On my side the issue from your code was reproduced with CLion 2017.3.3 and wasn't reproduced with 2018.1 EAP.