C++: Lift getTypeOperand to a superclass

[MathiasVP]

Both sizeof(myType) and sizeof(myExpr) exists in C/C++, and we currently have a class for each case (SizeofTypeOperator and SizeofExprOperator, respectively) with a common superclass SizeofOperator.

This PR lifts the getTypeOperand member predicate from SizeofTypeOperator to the superclass with the intuitive implementation that, in the case of sizeof(myExpr) it should return the type of myExpr. This makes the superclass much more useful.

:til: there's also a __datasizeof in Clang so I made a similar transformation on that one.

[Copilot]

Pull Request Overview

This PR lifts the getTypeOperand() method from the SizeofTypeOperator subclass to the SizeofOperator superclass, making it available for both type and expression operands. For sizeof(myExpr), the method now returns the type of the expression. The same transformation is applied to the DatasizeofOperator hierarchy.

Key Changes:

• Added getTypeOperand() to SizeofOperator and DatasizeofOperator base classes with default implementation { none() }
• Implemented overrides in expression operator subclasses to return the type of the contained expression
• Updated test to call the method on the superclass, demonstrating it now works for all sizeof variants

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
cpp/ql/lib/semmle/code/cpp/exprs/Cast.qll	Added getTypeOperand() to superclasses SizeofOperator and DatasizeofOperator, with appropriate overrides in subclasses
cpp/ql/test/library-tests/types/sizeof/sizeof.ql	Updated test to call getTypeOperand() on SizeofOperator instead of SizeofTypeOperator
cpp/ql/test/library-tests/types/sizeof/sizeof.expected	Updated expected results to include type operands for expression-based sizeof operations

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[jketema]

:til: there's also a __datasizeof in Clang so I made a similar transformation on that one.

That's a pretty recent addition actually.

[jketema]

LGTM if CI and DCA are happy.

[MathiasVP]

DCA was uneventful. Merging!