Objective-C Language Guide¶

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

Supported File Extensions¶

.m
.mm
.h (auto-detected based on content)

Required Tools¶

Linter: cpplint¶

pip install cpplint

Formatter: clang-format¶

# macOS
brew install clang-format

# Or install LLVM
brew install llvm

Configuration¶

Basic Example¶

# .linthis/config.toml

[oc]
linelength = 120
excludes = ["Pods/**", "Carthage/**"]
cpplint_filter = "-build/header_guard,-runtime/int"

Alternative key name:

[objectivec]
linelength = 120

Clang-tidy Ignored Checks¶

[oc]
clang_tidy_ignored_checks = [
    "clang-analyzer-osx.cocoa.RetainCount",
    "clang-analyzer-osx.cocoa.SelfInit"
]

Custom Rules¶

[[rules.custom]]
code = "oc/no-nslog"
pattern = "NSLog\\s*\\("
message = "Remove NSLog before release"
severity = "warning"
languages = ["oc"]

[[rules.custom]]
code = "oc/arc-bridge"
pattern = "__bridge"
message = "Review ARC bridge usage"
severity = "info"
languages = ["oc"]

CLI Usage¶

# Check Objective-C files only
linthis -c --lang oc

# Format Objective-C files only
linthis -f --lang oc

Clang-Format Configuration¶

Create .clang-format:

BasedOnStyle: Google
Language: ObjC
ObjCSpaceAfterProperty: true
ObjCSpaceBeforeProtocolList: true
ColumnLimit: 120

Header File Detection¶

linthis automatically detects .h files as Objective-C when they contain: - #import or @import statements - @interface, @implementation, @protocol - NS types (NSString, NSArray, etc.) - Objective-C method syntax (+ (, - ()

Common Issues¶

.h files detected as C++¶

If .h files are incorrectly detected, ensure they contain Objective-C patterns or explicitly specify:

linthis -c --lang oc src/

Pods/Carthage being checked¶

Add to excludes:

[oc]
excludes = ["Pods/**", "Carthage/**", "Vendor/**"]

Best Practices¶

Use .clang-format: Consistent formatting for ObjC-specific style
Exclude dependencies: Add Pods/Carthage to excludes
ARC considerations: Review __bridge usage warnings
NSLog cleanup: Remove debug logging before release