Commit b19461b1 authored Dec 01, 2022 by Leon Scroggins III

Prevent calling new ftl::Optional

This class inherits from std::optional, which does not have a virtual
destructor. As such, deleting an object of ftl::Optional using a pointer
to its base class has undefined behavior. Prevent this by removing new
from ftl::Optional. This is generally not the right way to use it
anyway, and in fact this builds as is.

Delete new[] while we're at it. This should be enough of a signal not to
try to heap allocate these. It's still possible for a programmer to
circumvent these deletions, but they prevent the straightforward
(broken) use case.

Bug: 261035092
Test: make
Change-Id: Iafdaf98ed88920162af2b445caf0e4a69be51ab5

parent 95538a1c

include/ftl/optional.h

+8 −0

Original line number	Diff line number	Diff line
		@@ -95,6 +95,14 @@ struct Optional final : std::optional<T> {
		if (has_value()) return std::invoke(std::forward<F>(f), std::move(value()));
		return R();
		}

		// Delete new for this class. Its base doesn't have a virtual destructor, and
		// if it got deleted via base class pointer, it would cause undefined
		// behavior. There's not a good reason to allocate this object on the heap
		// anyway.
		static void* operator new(size_t) = delete;
		static void* operator new[](size_t) = delete;

		};

		template <typename T, typename U>