C++ Language Guide¶

linthis uses cpplint and clang-tidy for linting, and clang-format for formatting C/C++ code.

Supported File Extensions¶

.c, .cc, .cpp, .cxx
.h, .hpp, .hxx

Required Tools¶

Linter: cpplint¶

# Install via pip
pip install cpplint

# Verify installation
cpplint --version

Linter: clang-tidy (optional, additional checks)¶

# macOS
brew install llvm

# Ubuntu/Debian
sudo apt install clang-tidy

# Windows
choco install llvm

# Verify installation
clang-tidy --version

Formatter: clang-format¶

# macOS
brew install clang-format

# Ubuntu/Debian
sudo apt install clang-format

# Windows
choco install llvm

# Verify installation
clang-format --version

Configuration¶

Basic Example¶

# .linthis/config.toml

[cpp]
max_complexity = 25
linelength = 120
excludes = ["build/**", "third_party/**"]

Cpplint Filter¶

Disable specific cpplint checks:

[cpp]
cpplint_filter = "-build/c++11,-whitespace/tab,-build/header_guard"

Clang-tidy Checks¶

Ignore specific clang-tidy checks:

[cpp]
clang_tidy_ignored_checks = [
    "modernize-use-trailing-return-type",
    "readability-magic-numbers"
]

Disable Specific Rules¶

[cpp.rules]
disable = [
    "build/include_order",
    "whitespace/braces"
]

Custom Rules¶

[[rules.custom]]
code = "cpp/no-raw-pointer-new"
pattern = "new\\s+\\w+"
message = "Consider using smart pointers instead of raw new"
severity = "warning"
suggestion = "Use std::make_unique or std::make_shared"
languages = ["cpp"]

[[rules.custom]]
code = "cpp/no-goto"
pattern = "\\bgoto\\b"
message = "Avoid using goto"
severity = "error"
languages = ["cpp"]

CLI Usage¶

# Check C++ files only
linthis -c --lang cpp

# Format C++ files only
linthis -f --lang cpp

Clang-Format Configuration¶

Create .clang-format:

BasedOnStyle: Google
IndentWidth: 4
ColumnLimit: 120
AllowShortFunctionsOnASingleLine: Inline
BreakBeforeBraces: Attach

Cpplint Configuration¶

Create CPPLINT.cfg in your project root:

linelength=120
filter=-build/c++11,-whitespace/tab

Common Issues¶

.h files detected as wrong language¶

linthis uses smart detection for .h files. If misdetected, you can force the language:

linthis -c --lang cpp src/

Cpplint not found¶

Warning: No cpp linter available for cpp files
  Install: pip install cpplint

Third-party code being checked¶

Add to excludes:

[cpp]
excludes = ["third_party/**", "external/**", "vendor/**"]

Best Practices¶

Use .clang-format: Consistent formatting across your project
Line length: 120 characters is common for modern displays
Header guards: Consider using #pragma once if cpplint complains
Smart pointers: Enable warnings for raw pointer usage