be-code-style

## What I do Fix C++ code formatting issues in the BE and Cloud modules using the project's clang-format configuration (v16). ## When to use me - Before committing BE/Cloud C++ code changes - When CI reports clang-format failures - When you need to check or fix C++ code style ## Prerequisites You need to confirm that the major version of the called clang-format is 16. If the current environment's default does not meet this requirement, try the following: 1. If `.vscode/settings.json` exists, use the clang-format.executable item in it. 2. If it is a worktree directory, use the `.vscode/settings.json` from the main directory. 3. Check the path to the compiler toolchain by trying to find it from the `PATH` environment variable, the current directory, and the main directory's `custom_env.sh`. Look for a clang-format with the major version number 16 in that path and its parent directory. ## Procedure ### Step 1: Auto-fix formatting Run the project's formatting script, which enforces clang-format v16: ```bash build-support/clang-format.sh ``` This formats all C++ files under `be/src`, `be/test`, `cloud/src`, `cloud/test` in-place, respecting `.clang-format` and `.clang-format-ignore`. **Important**: Always use this script instead of invoking `clang-format` directly. The script checks that clang-format version 16 is installed and exits with an error if the wrong version is found. Using a different version will produce inconsistent formatting. ### Step 2: Check-only (no modification) To verify formatting without modifying files: ```bash build-support/check-format.sh ``` This outputs a diff of any formatting violations and exits non-zero if there are any. ### Step 3: Review and commit After running `clang-format.sh`, review the changes with `git diff` to verify only formatting was changed, then stage and commit. ## Key Configuration | File | Purpose | |------|---------| | `.clang-format` | Main formatting rules (Google-based, 100 col, 4-space indent) | | `.clang-format-ignore` | Files excluded from formatting (third-party, generated) | | `build-support/run_clang_format.py` | Python wrapper for parallel execution | ## Excluded Directories The following are excluded from formatting (see `.clang-format-ignore`): - `be/src/apache-orc/*`, `be/src/clucene/*`, `be/src/gutil/*` - `be/src/glibc-compatibility/*` - Specific third-party vendored files (mustache, sse2neon, utf8_check) - `cloud/src/common/defer.h` ## Troubleshooting | Problem | Solution | |---------|----------| | `clang-format not found` | Install clang-format v16 or set `CLANG_FORMAT_BINARY` env var | | `version is not 16` | Install clang-format v16; on macOS: `brew install llvm@16` | | Files not being formatted | Check `.clang-format-ignore` for exclusions |