# VERIFY_INTERFACE_HEADER_SETS

Added in version 3.24.

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

When this property is set to true, and the target is an object library, static library, shared library, interface library, or executable (subject to policy `CMP0209`) and the target has one or more `PUBLIC` or `INTERFACE` header sets, an object library target named `<target_name>_verify_interface_header_sets` is created. This verification target has one source file per header in the `PUBLIC` and `INTERFACE` header sets. Each source file only includes its associated header file. The verification target links against the original target to get all of its usage requirements.

The verification target has its `EXCLUDE_FROM_ALL` and `DISABLE_PRECOMPILE_HEADERS` properties set to true, and its `AUTOMOC`, `AUTORCC`, `AUTOUIC`, `UNITY_BUILD`, and `CXX_SCAN_FOR_MODULES` properties set to false.

If the header's `LANGUAGE` property is set, the value of that property is used to determine the language with which to compile the header file. Otherwise, if the target has any C++ sources, the header is compiled as C++. Otherwise, if the target has any C sources, the header is compiled as C. Otherwise, if C++ is enabled globally, the header is compiled as C++. Otherwise, if C is enabled globally, the header is compiled as C. Otherwise, the header file is not compiled.

If the header's `SKIP_LINTING` property is set to true, the file is not compiled.

If `VERIFY_INTERFACE_HEADER_SETS` and `VERIFY_PRIVATE_HEADER_SETS` are both set to true, headers belonging to `PUBLIC` file sets will be verified twice, but with different conditions. The compiler flags used for private and interface contexts can be different, leading to the compiler interpreting the contents of the header differently.

If any interface file set verification targets are created, a top-level target called `all_verify_interface_header_sets` is created which depends on all interface verification targets. Another target called `all_verify_header_sets` is also created which depends on `all_verify_interface_header_sets`, and on `all_verify_private_header_sets` if it exists (see `VERIFY_PRIVATE_HEADER_SETS`).

This property is initialized by the value of the `CMAKE_VERIFY_INTERFACE_HEADER_SETS` variable if it is set when a target is created.

If the project wishes to control which header sets are verified by this property, it can set `INTERFACE_HEADER_SETS_TO_VERIFY`.