VERIFY_PRIVATE_HEADER_SETS

.. versionadded:: 4.3

.. versionchanged:: 4.4 OBJC and OBJCXX languages are now supported in addition to C and CXX.

Used to verify that all headers in a target's PUBLIC and PRIVATE header sets can be included on their own.

.. versionchanged:: 4.4 Previously, the verification target was only created when the target had at least one matching header. Now it is always created when the property is enabled.

When this property is set to true, and the target is an object library, static library, shared library, module library, interface library, or executable, an object library target named <target_name>_verify_private_header_sets is created. This verification target has one source file per header in the target's PUBLIC and PRIVATE header sets. Each source file only includes its associated header file. If the target has no matching header sets, a utility target is created instead so that the target name always exists for build system dependencies.

Properties affecting compilation are copied from the original target to the verification target so that the headers will be interpreted the same way by the compiler as when compiling the original target's sources. There are some caveats with this approach. It cannot replicate the same conditions if any of those properties or properties inherited through build requirements from transitive dependencies contain :ref:target-dependent generator expressions <Target-Dependent Expressions> that do not specify the target for the expansion. Such expressions can expand to different contents depending on the target they are being used on.