Disable a Windows platform warning.

[clalancette]

Signed-off-by: Chris Lalancette clalancette@openrobotics.org

This should get rid of most of the warnings we are currently getting from the Windows CI jobs, as seen in https://ci.ros2.org/view/nightly/job/nightly_win_deb/1804/msbuild . See the diff for a better explanation of why we have to do this.

[clalancette]

CI:

• Linux
• Linux-aarch64
• macOS
• Windows

[clalancette]

Looks like I missed one in time_win32.c; that should now be fixed. Otherwise, initial CI looks pretty good. I'm going to run a full CI just to make sure that everything still works for all downstreams as well. I expect that to still have one warning on Windows, which needs a separate patch for RViz.

CI:

• Linux
• Linux-aarch64
• macOS
• Windows

[ivanpauno]

LGTM!

I'm surprised I couldn't find any issue saying this can happen without using /experimental:preprocessor, but maybe Windows introduced a bug in MSVC yesterday (?).

The other option is that we're enabling that compiler flag accidentally.
It would be good to double check that.

[clalancette]

I'm surprised I couldn't find any issue saying this can happen without using /experimental:preprocessor, but maybe Windows introduced a bug in MSVC yesterday (?).

So we don't have /experimental:preprocessor on, as far as I can tell. We do turn on /Zc:preprocessor (the successor to /experimental:preprocessor) in one place: https://github.com/ros2/rosidl/blob/e22083c970f6235ef4266bab80947f9dbc316c37/rosidl_generator_cpp/CMakeLists.txt#L108 . But as far as I can tell, that should only be for that particular test, so it wouldn't be a global thing.

I'm going to go ahead and merge this as-is to reduce our warnings for now. If Windows/MSVC gets fixed, or we figure out that we are accidentally turning on flags, we can always revert this.

[clalancette]

(oh, and all of the failures on Windows are there on the nightlies as well)

[ivanpauno]

/Zc:preprocessor (the successor to /experimental:preprocessor) in one place: https://github.com/ros2/rosidl/blob/e22083c970f6235ef4266bab80947f9dbc316c37/rosidl_generator_cpp/CMakeLists.txt#L108 .

Yeah, I saw that one.

But as far as I can tell, that should only be for that particular test, so it wouldn't be a global thing.

Agreed, I don't think that will affect other places.