Hundreds of warnings while compiling AirSim for Unity on Linux

[rajat2004]

OS: Ubuntu 18.04
Unity 2019.f2

Reproduction -

cd Unity
./build.sh

And watch as hundreds of warnings(about 340) scroll by on your screen. Total output size after redirecting it to a file comes out to be 9 MB

I believe this is happening due to compiler warning flags used to compile RPC being applied to the entire source code. This is quite bothersome, especially when trying to setup Travis for testing where the max output size is 4 MB, and thus requires additional workarounds to reduce output

From my poking around and diving into the CMake files, the problem seems to occur due to -

1. Unity/AirlibWrapper has it's own CMakeLists.txt, where cmake/rpc-setup.cmake is included, which is modified from the original one used in RPC

2. CMake project() is used here, which is the first and the only instance of this being used in the Unity CMake setup, and hence defines the PROJECT_NAME in all the subsequent ones

rpc-setup.cmake sets the compiler flags for the project, and this causes them to be applied everywhere. Usage of PROJECT_NAME can be seen by searching for it in the file

Such a thing doesn't happen in Unreal because it uses a wrapper over RPC's CMakeList itself with a separate project which doesn't affect the other files

This is just my current understanding of trying to figure of why this is happening. I'm not experienced in using CMake, and would love to have others's input in trying to figure out this problem

[saihv]

Well, using -Weverything will do that I guess : https://github.com/microsoft/AirSim/blob/master/Unity/AirLibWrapper/AirsimWrapper/cmake/rpc-setup.cmake#L271

I don't think such heavy diagnostics are needed for us, especially when our code doesn't really adhere to any of those standards. I think we should relax the warning level by removing -Weverything and use -Wall and maybe -Wextra.

@madratman

[rajat2004]

Removing some of the warning flags might reduce the amount, but this doesn't address the core problem here as far as I understand currently

[rajat2004]

#2672 reduces the warnings, but I feel that the issue (if I'm correct in my understanding) is still applicable. Therefore keeping the issue open for now

[stale]

This issue has been automatically marked as stale because it has not had activity from the community in the last year. It will be closed if no further activity occurs within 20 days.