[Confusion] about ${PROJECT_NAME}_BUILD_SHARED_LIBS

[Kiddinglife]

Describe the issue I am confused about the below cmake snippets in StandardSettings.cmake:

# Export all symbols when building a shared library
if(${PROJECT_NAME}_BUILD_SHARED_LIBS)
    set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS OFF)
    set(CMAKE_CXX_VISIBILITY_PRESET hidden)
    set(CMAKE_VISIBILITY_INLINES_HIDDEN 1)
endif()

As cmake tool will build all the libraries as shared library when BUILD_SHARED_LIBS is ON, my understnading is that we should overwrite the cmake built-in cache variable of BUILD_SHARED_LIBS when ${PROJECT_NAME}_BUILD_SHARED_LIBS is ON. Something looks like this:

# Export all symbols when building a shared library
if(${PROJECT_NAME}_BUILD_SHARED_LIBS)
    set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS OFF)
    set(CMAKE_CXX_VISIBILITY_PRESET hidden)
    set(CMAKE_VISIBILITY_INLINES_HIDDEN 1)
    set(BUILD_SHARED_LIBS ON CACHE BOOL "build shared libraries except when explicitely set to static" FORCE)
endif()

Let me know what you think it.

To Reproduce None

Expected behavior Overwrite the cmake built-in cache variable of BUILD_SHARED_LIBS when ${PROJECT_NAME}_BUILD_SHARED_LIBS is ON

Desktop (please complete the following information):

• OS: Windows
• Version 10
• Editor: vscode