Why autoware don't support building with clang

[zulfaqar-azmi-t4]

I experimented with using Clang for Autoware and encountered several package failures. I suspect these issues are primarily due to the stringent error handling enforced in autoware_package.cmake for clang compiler.

Despite these challenges, I've identified notable advantages of employing Clang:

1. It offers a range of advanced compiler flags. For instance, -ftime-trace proves particularly beneficial, especially given the increasing build times for Autoware.
2. Clang excels in detecting potential vulnerabilities that g++ doesn't, such as uninitialized variables, enhancing code safety and robustness.

Regarding the error handling concerns, a practical approach could be to initially lower the error handling level and gradually raise it. This suggestion comes from my relatively limited experience, but I believe that while GCC is widely supported across various architectures, there should be no fundamental impediments to compiling the code with Clang.

[felixf4xu]

I have never tried but I'm interested to see if there is any benefit from building with clang. Maybe I will try with my current working packages.

My suggestion would be to raise some specific issues or PRs at a package-by-package step. If the change is beneficial when building with clang and does no harm when building with gcc, I would see a high possibility to get the PR merged.

[felixf4xu]

autowarefoundation/autoware.universe#2773 (comment)

it's mentioned that some branch can be built with clang.