Clang Tidy & Format Integration

[bcaddy]

Clang-Format

Clang-format can be run in a variety of ways.

• Running the tools/clang-format_runner.sh script
• Running make format
• Integrating into your IDE/editor
• Integrating into git hook

Tested with clang-format 15

Added the following

• .clang-format file with the formatting we decided on based off of Google's format
• .git-blame-ignore-revs file to help us ignore formatting changes, see that file for how to implement it for you
• whitespace removal commit added to .git-blame-ignore-revs
• tools/clang-format_runner.sh script to run clang-format on all the C++ source files in Cholla
• code_formatting.yml GitHub Actions workflow automatically check formatting on each push and PR
  • I suggest you enable GitHub Actions in your fork of Cholla so that this action will run on each push and warn you if you code isn't formatted.
  • This could be extended to include formatting for our Python code in the future

Clang-Tidy

clang-tidy can be run by running make tidy. Tested with clang-tidy 15.

• Add .clang-tidy file
  • Disables checks we probably don't want to run
  • Set naming convention based on our current discussion
  • Disables all checks that we do want to run but that aren't passing yet
• Integrate clang-tidy into build system
• Add clang-tidy run to build workflow and rename it "Build & Lint"
  • Since it shares most of the setup with the build and there's no point in linting if it doesn't even compile I added the clang-tidy run to the end of the build
• Add a new tools/analyze_tidy_checks.py script that prints a summary of the failed clang-tidy checks and how many times each check failed
• Tweak hydro_cuda_tests to work with clang-tidy on ROCm

Docker

• Add docker files to Cholla repo
• Point GHA at new images that contain clang tools and are owned by the new "chollahydro" user on DockerHub. I'm sure we can get everyone access to this but I don't know how right now. For now both Evan and I have the login info.

Other

• Remove -foffload=disable as it's no longer used
• Rename cpp-lint action to code_formatting
• Add readme badges for new workflow
• Remove extraneous googletest build from GHA builds

Standing Issues

Here's some outstanding issues we need to address before this can be merged. I've tagged the people I think are most relevant for each issue, if I get anything wrong please let me know and I will correct it.

• The code isn't actually formatted yet. Once we decide it's time for that I can run the formatting and add the formatting commit to .git-blame-ignore-revs (@bcaddy)
• We haven't officially nailed down our naming convention. I set it up with what I think we've decided on but we should discuss that for sure. (@helenarichie )
• clang-tidy currently doesn't pass on all builds as it throws several clang-diagnostic-error errors. These are errors from the clang compiler, not clang-tidy and so cannot be turned off. I believe all the errors will be easy to fix, and I already fixed one, but some of them are in areas of the code I haven't touched and so I'd appreciate it if others looked into it. Here's a list of the current errors, all are on ROCm builds:
  • /cholla/cholla/src/gravity/paris/HenryPeriodic.cu:85:42: error: use of undeclared identifier 'cudaHostAllocDefault' [clang-diagnostic-error] - Either helping it find the macro or replace with a standard allocation (or std::vector)
  • /cholla/cholla/src/particles/feedback_CIC_gpu.cu:382:32: error: no matching function for call to 'atomicMax' [clang-diagnostic-error] - (@ojwg)
  • /opt/rocm-5.2.3/include/hiprand/hiprand_kernel_nvcc.h:43:1: error: typedef redefinition with different types ('struct hiprandStateMRG32k3a' vs 'struct curandStateMRG32k3a') [clang-diagnostic-error] - I'm not sure how to deal with this one since it's not in our code. Maybe @twhite-cray or Damon have some ideas.

[bcaddy]

This PR is pretty much done. I've added clang-tidy documentation to the Making a Pull Request section of the wiki. All that's left is:

• [x] Rebase once the MHD stuff is merged in
• [x] Format the code
• [x] Add format SHA to .git-blame-rev-ignore-revs

[bcaddy]

@ojwg, I had to make some minor tweaks to feedback_CIC_gpu.cu to get it to pass clang-tidy. Could you review them to make sure they're ok?

@evaneschneider, Once @ojwg's review is done this is ready to merge