**Introduction** The topic has been discussed several times either directly (e.g. [cmake-api-for-warnings](https://cmake-developers.cmake.narkive.com/uBwDXnJN/cmake-api-for-warnings))[1] or indirectly (e.g. [reliably use target_compile_options()](https://gitlab.kitware.com/cmake/cmake/issues/19084)[2]) After some surveys. I found that [cmake-api-for-warnings](https://cmake-developers.cmake.narkive.com/uBwDXnJN/cmake-api-for-warnings)[1] seems to reach a conclusion while there has been no implementation since then. And [Add options to enable all compiler warnings and to treat compiler warnings as errors](https://gitlab.kitware.com/cmake/cmake/issues/17743)[3] followed up the topic and proposed some implementation thoughts. However the discussion did not end up with final conclusion nor working patches. **Proposed Feature and Design** The following only take clang and gcc into discussion. But the idea is meant to generalized to other compilers. Two target properties `COMPILE_WARNING_MODE` and `COMPILE_WARNING_AS_ERROR` are added. `COMPILE_WARNING_MODE` is initialized by `CMAKE_COMPILE_WARNING_MODE` global variable. It takes the following values: `DEFAULT` (expands to nothing), `DISABLED`(expands to "-w" for clang/gcc/msvc), `HIGH`(expands to "-Wall -Wextra" for clang/gcc and "-W4" for msvc). `COMPILE_WARNING_AS_ERROR` is initialized by `CMAKE_COMPILE_WARNING_AS_ERROR`. It is a boolean variable. If it is true, it expands to "-Werror" for clang/gcc and "-WX" for msvc. It expands to nothing otherwise. These two target properties do not have `INTERFACE_*` counterparts thus do not propagate to targets that depend on them. **Reference** * cmake-api-for-warnings [https://cmake-developers.cmake.narkive.com/uBwDXnJN/cmake-api-for-warnings](https://cmake-developers.cmake.narkive.com/uBwDXnJN/cmake-api-for-warnings)[1] * reliably use target_compile_options() [https://gitlab.kitware.com/cmake/cmake/issues/19084](https://gitlab.kitware.com/cmake/cmake/issues/19084)[2] * Add options to enable all compiler warnings and to treat compiler warnings as errors [https://gitlab.kitware.com/cmake/cmake/issues/17743](https://gitlab.kitware.com/cmake/cmake/issues/17743)[3]