[cmake-developers] -isystem suppresses warnings from user header

[Brad King]

On 04/07/2016 10:03 AM, Tamás Kenéz wrote:
> CMake uses "-isystem" on the compiler command line for the
> INTERFACE_INCLUDE_DIRECTORIES of imported libraries.
> 
> Question: is this the intended behaviour?

Yes.  See discussion here:

* http://thread.gmane.org/gmane.comp.programming.tools.cmake.devel/7533

and implementation here:

* Always consider includes from IMPORTED targets to be SYSTEM.
  https://cmake.org/gitweb?p=cmake.git;a=commitdiff;h=a63fcbcb

> Can I force the -I flag somehow for my library?

Look at these:

* https://cmake.org/cmake/help/v3.5/variable/CMAKE_NO_SYSTEM_FROM_IMPORTED.html
* https://cmake.org/cmake/help/v3.5/prop_tgt/NO_SYSTEM_FROM_IMPORTED.html

-Brad