Foo::MozCanRunScript() {
  mBar->MaybeCanRunScript(this);
}

is considered as not safe. I.e., it seems that the following two code blocks might be considered as different:

Foo::MozCanRunScript() {
  AnotherCanRunScript();
}

Foo::MozCanRunScript() {
  this->AnotherCanRunScript();
}

When MozCanRunScript() is called, the instance of Foo should be grabbed with local RefPtr or something. Therefore, this in MOZ_CAN_RUN_SCRIPT methods should be safe.

>Foo::MozCanRunScript() {
>  mBar->MaybeCanRunScript(this);
>}

This would be considered unsafe because it's using mBar, which might get nulled out by the script running.

We don't seem to have explicit tests for the "this->AnotherCanRunScript()" case, but I just added one and it passes. I'll attach that here, but could you please double-check whether the problem you're actually running into is with "this" or with mBar?

I'm going to sneak this testcase into some other changes I'm making to the static analysis anyway.

(In reply to Boris Zbarsky [:bzbarsky, bz on IRC] from comment #1)

We don't seem to have explicit tests for the "this->AnotherCanRunScript()" case, but I just added one and it passes. I'll attach that here, but could you please double-check whether the problem you're actually running into is with "this" or with mBar?

Oh, right. I confirmed that ^ is under the "m" of "mBar". Sorry for taking your time.