[clang-tidy] `bugprone-exception-escape` didn't detech catching of an exception with pointer type by `void *` exception handler (#99773)

As in title, code which checks eligibility of exceptions with pointer
types to be handled by exception handler of type `void *` disallowed
this case. It was working like this:

```c++
if (isStandardPointerConvertible(ExceptionCanTy, HandlerCanTy) &&
          isUnambiguousPublicBaseClass(
              ExceptionCanTy->getTypePtr()->getPointeeType().getTypePtr(),
              HandlerCanTy->getTypePtr()->getPointeeType().getTypePtr())) {
```

but in `isUnambiguousPublicBaseClass` there was code which looked for
definitions:

```c++
bool isUnambiguousPublicBaseClass(const Type *DerivedType,
                                  const Type *BaseType) {
  const auto *DerivedClass =
      DerivedType->getCanonicalTypeUnqualified()->getAsCXXRecordDecl();
  const auto *BaseClass =
      BaseType->getCanonicalTypeUnqualified()->getAsCXXRecordDecl();
  if (!DerivedClass || !BaseClass)
    return false;
```

This code disallowed usage of `void *` type which was already correctly
detected in `isStandardPointerConvertible`.

AFAIK this seems like misinterpretation of specification:

> 14.4 Handling an exception
> a standard [pointer conversion](https://eel.is/c++draft/conv.ptr) not
involving conversions to pointers to private or protected or ambiguous
classes
(https://eel.is/c++draft/except.handle#3.3.1)

and 

> 7.3.12 Pointer conversions
> ... If B is an inaccessible
([[class.access]](https://eel.is/c++draft/class.access)) or ambiguous
([[class.member.lookup]](https://eel.is/c++draft/class.member.lookup))
base class of D, a program that necessitates this conversion is
ill-formed[.](https://eel.is/c++draft/conv.ptr#3.sentence-2) ...
(https://eel.is/c++draft/conv.ptr#3)

14.4 is carving out private, protected, and ambiguous base classes, but
they are already carved out in 7.3.12 and implemented in
`isStandardPointerConvertible`

---------

Co-authored-by: Piotr Zegar <me@piotrzegar.pl>

0 files changed, 0 insertions, 0 deletions