EPITA C/C++ Coding Style Checker

A fast C and C++ linter for EPITA coding style rules. Uses tree-sitter for robust AST-based parsing.

Features

• C (.c, .h) and C++ (.cc, .hh, .hxx) support
• 54 rules across file formatting, functions, exports, preprocessor, declarations, control flow, naming, and more
• AST-based checks via tree-sitter (no regex hacks for structure)
• clang-format integration with language-specific configs (C vs C++)
• Configurable via TOML, presets, or CLI flags
• Pre-commit hook support

Installation

pipx install epita-coding-style

Requires Python >= 3.10, and clang-format on PATH for the format check (skipped with a warning otherwise).

Quick Start

epita-coding-style src/           # Check files/directories
epita-coding-style --list-rules   # List all rules with descriptions
epita-coding-style --show-config  # Show current configuration
epita-coding-style --help         # Full usage info

Example Output

$ epita-coding-style src/
src/rbtree.c:1:1: error: No blank lines at start of file [epita-file.spurious]

src/rbtree.c:307:1: error: 'rb_delete_cases' has 5 args (max 4) [epita-fun.arg.count]
static void rb_delete_cases(struct rb_node **node, struct rb_node **tmp,
src/rbtree.c:12:1: error: 2 exported globals (max 1) [epita-export.other]
src/rbtree.c:1:1: error: 36 lines need formatting [epita-format]

Files: 1  Major: 4  Minor: 0

Fix formatting: clang-format -i src/rbtree.c

Supported File Extensions

C++ files using .cpp / .hpp will be checked but flagged with a file.ext violation.

Configuration

Configuration is auto-detected from (in order):

• .epita-style
• .epita-style.toml
• epita-style.toml
• [tool.epita-coding-style] in pyproject.toml

Priority: CLI flags > config file > preset > defaults

Generate a Config File

epita-coding-style --show-config --no-color > .epita-style.toml

This outputs a complete, commented TOML config you can customize.

Presets

epita-coding-style --preset 42sh src/      # 40 lines, goto/cast allowed
epita-coding-style --preset noformat src/  # Same + skip clang-format

Example Config

# .epita-style.toml
max_lines = 40

[rules]
"keyword.goto" = false  # Allow goto
"cast" = false          # Allow casts

Or in pyproject.toml:

[tool.epita-coding-style]
max_lines = 40

[tool.epita-coding-style.rules]
"keyword.goto" = false

Limits

Rules Overview

Use epita-coding-style --list-rules for the full list. Key categories:

C rules (enabled by default):

• File: line endings, trailing whitespace, blank lines at edges or consecutive, file termination
• Style: Allman brace style
• Functions: length, argument count, (void) for empty params
• Exports: max exported functions/globals per .c file
• Preprocessor: include guards, # column, #endif comments, digraphs, multi-line comment style
• Declarations: one per line, no VLAs, no inline assembly, no comma operator outside for
• Control: no empty loop bodies
• Strict: no goto, no explicit casts
• Formatting: clang-format compliance

C++ rules (auto-enabled for .cc/.hh/.hxx files):

• File: correct extensions (.cc/.hh/.hxx, not .cpp/.hpp)
• Preprocessor: #pragma once, include order, no source includes, constexpr
• Global: C++ casts, no malloc, nullptr, no extern "C", C++ headers, std:: functions
• Naming: CamelCase classes/structs, lowercase namespaces with closing comments
• Declarations: &/* next to type, explicit constructors, no VLAs
• Control: switch default case, label padding, no empty loops
• Writing: empty braces, single-expression braces, throw/catch rules, operator overloads, enum class, no (void) in empty param lists

clang-format

The format rule uses clang-format to check code formatting. Requires clang-format to be installed.

The checker uses language-specific configs:

• C: looks for .clang-format-c, then .clang-format
• C++: looks for .clang-format-cxx, then .clang-format

It searches from the file's directory up to root, falling back to the bundled EPITA configs.

To disable: set "format" = false in your config, or use --preset noformat.

Editor Integration

Neovim: epita-nvim-lint lints on save via nvim-lint.

Any editor that parses GCC-style diagnostics (file:line:col: error: ...) works out of the box, e.g. Vim's :make with makeprg=epita-coding-style\ %.

Pre-commit Hook

# .pre-commit-config.yaml
repos:
  - repo: https://github.com/KazeTachinuu/epita-coding-style
    rev: v3.3.1
    hooks:
      - id: epita-coding-style
        args: [--preset, 42sh]  # optional

Update the pinned rev with pre-commit autoupdate.

With the tool already installed, ./setup-hooks.sh sets up a local hook instead.

License

MIT