The old code for member method calls did the following:
- Find the member method calls.
- Look at their "this" expression.
- If the "this" is an operator call, check for any of the arguments of the
operator call being invalid.
- Otherwise (if not an operator call) check for the "this" value being
This wasn't right, because the "is invalid" check checks the type and only
considers refcounted things. So if the code looked something like
"foo[i]->call_method()", we would look at the types of "foo" and "i" and
determine that none of those are refcounted types so there is nothing invalid
here (since "foo" is some sort of array type and "i" is an integer). The new
setup just checks whether the "this" value is invalid, which does the type
check on the "this" value itself; in the "foo[i]->call_method()" case on
"foo[i]". We then adjust the exclusions in InvalidArg to consider operator->
on known-live things valid, to allow the thing that we were really trying to
accomplish with the "check for an operator call" bits:
The test coverage being added for the made-up TArray type is meant to catch
things like the geolocation issue that was being hidden by the buggy behavior.
I'm not using nsTArray itself because some header included by nsTArray.h
tries to define operator new/delete bits inline and that triggers warnings that
then cause a clang-plugin test failure, because they're unexpected.