Objective-C Bindings

cjbind can parse Objective-C headers and generate Cangjie bindings with the --objc option.

Basic Usage

The simplest form looks like this:

$ cjbind --objc Foundation/NSString.h

If you also need to pass SDK paths, framework search paths, or other clang arguments, put them after --:

$ cjbind --objc UIKit/UIView.h -- -isysroot /path/to/SDK -F/path/to/Frameworks

Supported Declarations

Objective-C mode is primarily aimed at declarations found in headers, including:

• @interface
• @protocol
• categories
• instance methods and class methods
• properties
• block parameters
• nullability information
• lightweight generic names as comments

The generated output is mapped into classes, interfaces, extensions, and the corresponding methods and properties.

Code Generation Modes

--objc-codegen-mode provides two modes.

runtime

runtime is the default mode. It generates wrappers based on the Objective-C Runtime and dispatches calls through functions such as objc_msgSend, objc_getClass, and sel_registerName.

This mode is closer to direct runtime bridging and is suitable when the runtime environment is already in place and you want to use Objective-C APIs as regular Cangjie wrappers.

$ cjbind --objc --objc-codegen-mode runtime Foundation/NSString.h

compiler

compiler mode generates declarations with annotations such as @ObjCMirror, @ForeignName, @ObjCInit, and @ObjCOptional, which is better suited for Cangjie's Objective-C interop layer.

$ cjbind --objc --objc-codegen-mode compiler Foundation/NSString.h

If you want generated methods to include stub bodies with default return values so the code can compile earlier in the workflow, add --objc-generate-definitions:

$ cjbind --objc --objc-codegen-mode compiler --objc-generate-definitions Foundation/NSString.h

Usage Notes

• Pass complete system header and framework search paths to clang, or many Objective-C types will fail to resolve correctly.
• Prefer runtime mode when your goal is direct Runtime-based dispatch.
• Prefer compiler mode when your goal is declaration-oriented code for Cangjie interop.
• Review generated code manually for APIs that depend on ownership, lifetime, or unusual ABI behavior.

Related Limitations

Objective-C mode covers common declaration generation, but it does not infer higher-level framework semantics for you. For ownership, lifecycle, and unusual dispatch edge cases, also see Known Limitations.