CMake warnings under macOS

[claudiofantacci]

While configuring CMake, I get the following warning:

CMake Warning (dev) at src/rtf/CMakeLists.txt:8 (project):
   Policy CMP0048 is not set: project() command manages VERSION variables.
   Run "cmake --help-policy CMP0048" for policy details.  Use the cmake_policy
   command to set the policy and suppress this warning.

   The following variable(s) would be set to empty:

     RTF_VERSION
     RTF_VERSION_MAJOR
     RTF_VERSION_MINOR
     RTF_VERSION_PATCH
     RTF_VERSION_TWEAK
 This warning is for project developers.  Use -Wno-dev to suppress it.

During generation I get:

Policy CMP0042 is not set: MACOSX_RPATH is enabled by default.  Run "cmake
   --help-policy CMP0042" for policy details.  Use the cmake_policy command to
   set the policy and suppress this warning.

   MACOSX_RPATH is not specified for the following targets:

    RTF
    RTF_dll

 This warning is for project developers.  Use -Wno-dev to suppress it.

System: macOS 10.11.6 (El Capitan), CMake 3.7.0.

[claudiofantacci]

Project version shall be set in the project() command as reported here.

In the CMakeLists.txt the include(RTFVersion) should export a variable to be used in `project()', e.g.:

inlcude(RTFVersion)
project(RTF LANGUAGE CXX VERSION ${RTFVersionNumber})
...

This should be compliant with CMP0048 cc: @apaikan @traversaro @drdanz

[traversaro]

I am quite confused. If we use the new signature of project we break compatibility with CMake < 3.0 (not a big problem, considering https://github.com/robotology/QA/issues/173 and given that RTF is mostly a developer tool). However I wonder why we don't get this warning in the other libraries.

For the RPATH warning, the logic to set it properly can be found in https://github.com/robotology/ycm/blob/master/modules/AddInstallRPATHSupport.cmake .

[claudiofantacci]

As far as VERSION issue is concerned, @apaikan is also experiencing this warning on Windows. What I would guess about it, is that with the latest version of CMake (I have 3.7.1), developers are pushing to move users toward 3.0>. I have no problem with supporting older version (say 2.8>), but we may want to consider enforcing the policies and moving toward CMake 3.0.

As far as RPATH issue is concerned, I think we can use AddInstallRPATHSupport.cmake directly copying it into the config folder (and modifying CMakeLists accordingly). Am I right?

[drdanz]

I think this is the problem:

CMakeLists.txt:9

project(RTF)

# ...

# include version number
include(RTFVersion)

RTFVersion.cmake

set(RTF_VERSION_MAJOR "1")
set(RTF_VERSION_MINOR "0")
set(RTF_VERSION_PATCH "1")
set(RTF_VERSION_TWEAK "0")

# Generate RTF_VERSION
if(RTF_VERSION_TWEAK)
    set(RTF_VERSION "${RTF_VERSION_MAJOR}.${RTF_VERSION_MINOR}.${RTF_VERSION_PATCH}.${RTF_VERSION_TWEAK}")
else()
    set(RTF_VERSION "${RTF_VERSION_MAJOR}.${RTF_VERSION_MINOR}.${RTF_VERSION_PATCH}")
endif()

robot-testing/src/rtf/CMakeLists.txt:8

project(RTF)

The second project(RTF) is overriding the values set by RTFVersion. CMake checks if the variables set are empty and warns the uses. Just removing the second call (that is actually useless and confusing since it will overwrite several variables) should fix this warning. @claudiofantacci Can you please try?

[claudiofantacci]

I'm on it 👍