cpp-linter-hooks

A powerful pre-commit hook for auto-formatting and linting C/C++ code with clang-format and clang-tidy.

Table of Contents

• Quick Start
  • Custom Configuration Files
  • Custom Clang Tool Version
• Output
  • clang-format Output
  • clang-tidy Output
• Troubleshooting
  • Performance Optimization
  • Verbose Output
• Contributing
• License

Quick Start

Add this configuration to your .pre-commit-config.yaml file:

repos:
  - repo: https://github.com/cpp-linter/cpp-linter-hooks
    rev: v0.8.3  # Use the tag or commit you want
    hooks:
      - id: clang-format
        args: [--style=Google] # Other coding style: LLVM, GNU, Chromium, Microsoft, Mozilla, WebKit.
      - id: clang-tidy
        args: [--checks='boost-*,bugprone-*,performance-*,readability-*,portability-*,modernize-*,clang-analyzer-*,cppcoreguidelines-*']

Custom Configuration Files

To use custom configurations like .clang-format and .clang-tidy:

repos:
  - repo: https://github.com/cpp-linter/cpp-linter-hooks
    rev: v0.8.3
    hooks:
      - id: clang-format
        args: [--style=file]  # Loads style from .clang-format file
      - id: clang-tidy
        args: [--checks=.clang-tidy] # Loads checks from .clang-tidy file

Custom Clang Tool Version

To use specific versions of clang-tools:

repos:
  - repo: https://github.com/cpp-linter/cpp-linter-hooks
    rev: v0.8.3
    hooks:
      - id: clang-format
        args: [--style=file, --version=18] # Specifies version
      - id: clang-tidy
        args: [--checks=.clang-tidy, --version=18] # Specifies version

Output

clang-format Output

clang-format.............................................................Failed
- hook id: clang-format
- files were modified by this hook

Here’s a sample diff showing the formatting applied:

--- a/testing/main.c
+++ b/testing/main.c
@@ -1,3 +1,6 @@
 #include <stdio.h>
-int main() {for (;;) break; printf("Hello world!\n");return 0;}
-
+int main() {
+  for (;;) break;
+  printf("Hello world!\n");
+  return 0;
+}

Note

Use --dry-run in args of clang-format to print instead of changing the format, e.g.:

clang-format.............................................................Failed
- hook id: clang-format
- exit code: 255

main.c:2:11: warning: code should be clang-formatted [-Wclang-format-violations]
int main() {for (;;) break; printf("Hello world!\n");return 0;}
          ^
main.c:2:13: warning: code should be clang-formatted [-Wclang-format-violations]
int main() {for (;;) break; printf("Hello world!\n");return 0;}
            ^
main.c:2:21: warning: code should be clang-formatted [-Wclang-format-violations]
int main() {for (;;) break; printf("Hello world!\n");return 0;}
                    ^
main.c:2:28: warning: code should be clang-formatted [-Wclang-format-violations]
int main() {for (;;) break; printf("Hello world!\n");return 0;}
                           ^
main.c:2:54: warning: code should be clang-formatted [-Wclang-format-violations]
int main() {for (;;) break; printf("Hello world!\n");return 0;}
                                                     ^
main.c:2:63: warning: code should be clang-formatted [-Wclang-format-violations]
int main() {for (;;) break; printf("Hello world!\n");return 0;}
                                                              ^

clang-tidy Output

clang-tidy...............................................................Failed
- hook id: clang-tidy
- exit code: 1

522 warnings generated.
Suppressed 521 warnings (521 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
/home/runner/work/cpp-linter-hooks/cpp-linter-hooks/testing/main.c:4:13: warning: statement should be inside braces [readability-braces-around-statements]
    for (;;)
            ^
             {

Troubleshooting

Performance Optimization

Warning

If your pre-commit runs longer than expected, it is highly recommended to add files in .pre-commit-config.yaml to limit the scope of the hook. This helps improve performance by reducing the number of files being checked and avoids unnecessary processing. Here's an example configuration:

- repo: https://github.com/cpp-linter/cpp-linter-hooks
  rev: v0.8.3
  hooks:
    - id: clang-format
      args: [--style=file, --version=18]
      files: ^(src|include)/.*\.(cpp|cc|cxx|h|hpp)$ # Limits to specific dirs and file types
    - id: clang-tidy
      args: [--checks=.clang-tidy, --version=18]
      files: ^(src|include)/.*\.(cpp|cc|cxx|h|hpp)$

Alternatively, if you want to run the hooks manually on only the changed files, you can use the following command:

pre-commit run --files $(git diff --name-only)

This approach ensures that only modified files are checked, further speeding up the linting process during development.

Verbose Output

Note

Use -v or --verbose in args of clang-format to show the list of processed files e.g.:

repos:
  - repo: https://github.com/cpp-linter/cpp-linter-hooks
    rev: v0.8.3
    hooks:
      - id: clang-format
        args: [--style=file, --version=18, --verbose]   # Add -v or --verbose for detailed output

Contributing

We welcome contributions! Whether it's fixing issues, suggesting improvements, or submitting pull requests, your support is greatly appreciated.

License

This project is licensed under the MIT License.