[CMake] Policy CMP0063 is not set: Honor visibility properties for all target

[Alexander Shukaev]

On 06/18/2016 12:18 PM, Nils Gladitz wrote:
> On 18.06.2016 11:38, Alexander Shukaev wrote:
>>
>> I did try both variants, after and before
>>
>> cmake_minimum_required(VERSION)
>>
>> but the result is the same.  The scope is for sure parent to targets.
>
> I don't know what else it could be but this works fine for me:
>
>    cmake_minimum_required(VERSION 2.8.12)
>
>    if(POLICY CMP0063)
>         cmake_policy(SET CMP0063 NEW)
>    endif()
>
>    file(WRITE foo.cpp "int main() {}")
>
>    set(CMAKE_CXX_VISIBILITY_PRESET hidden)
>
>    add_executable(foo foo.cpp)
>
>
> Is it possible that the scope where the policy warning comes from has
> its own cmake_minimum_required(VERSION) call? (e.g. is there more than
> one?)
>
> Nils
>

You were right, Nils.  I have a CMake library that is pretty huge.  When 
one does `find_package' for it, then it will `include' all its modules 
into the client code.  Back when I started it, I didn't know that 
`cmake_minimum_required' can reset policies.  So there were a couple of 
modules that were still calling `cmake_minimum_required' which is 
clearly a bad practice.  I cleaned it up and it works now.

However, now the sequence is like this

xxx.cmake:

if(POLICY CMP0011)
   cmake_policy(SET CMP0011 NEW)
endif()
if(POLICY CMP0063)
   cmake_policy(SET CMP0063 NEW)
endif()

CMakeLists.txt:

include(xxx)
cmake_minimum_required(VERSION 3.1.0)

and it still works.  Is it because the version is high enough so it does 
not reset policies?

Alexander