Mach-O Assembler

A robust library for building and manipulating Mach-O (Mach Object) files, the standard executable format for macOS, iOS, and other Apple platforms.

🏛️ Architecture

graph TB
    subgraph "Mach-O Generation Pipeline"
        A[Mach-O Program Model] --> B[Load Command Builder]
        B --> C[Segment/Section Allocator]
        C --> D[Symbol Table Generator]
        D --> E[Mach-O Binary]
        
        subgraph "Format Variants"
            F[Object File .o]
            G[Executable]
            H[Dynamic Library .dylib]
        end
        
        E --> F
        E --> G
        E --> H
    end

🚀 Features

Core Capabilities

• Multi-Type Support: Generates Mach-O Object files, Executables, and Dynamic Libraries (.dylib).
• Load Command Management: Automatically constructs essential load commands like LC_SEGMENT_64, LC_SYMTAB, LC_DYSYMTAB, and LC_MAIN.
• Architecture Support: Full support for x86_64 and arm64 (Apple Silicon) binary layouts.

Advanced Features

• Fat Binary Support: Capability to bundle multiple architecture-specific Mach-O files into a single Universal Binary (🚧).
• Symbolic Linkage: Manages external symbols and dynamic library dependencies through LC_LOAD_DYLIB commands.
• Section Alignment: Precise control over memory alignment for text, data, and __objc sections.

💻 Usage

Creating a Mach-O Dynamic Library

The following example demonstrates how to write a Mach-O program model to a .dylib file.

use macho_assembler::{types::MachoProgram, dylib_write_path};
use std::path::Path;

fn main() {
    // 1. Create a Mach-O program model
    let mut macho = MachoProgram::default();
    macho.header.cputype = 0x01000007; // CPU_TYPE_X86_64
    
    // 2. Define segments and symbols (omitted for brevity)
    // ...

    // 3. Write to a .dylib file using the high-level API
    let output_path = Path::new("libexample.dylib");
    dylib_write_path(&macho, output_path).expect("Failed to write dylib");
    
    println!("Successfully generated libexample.dylib");
}

🛠️ Support Status

Legend: ✅ Supported, 🚧 In Progress, ❌ Not Supported

🔗 Relations

• gaia-types: Utilizes the BinaryWriter for precise byte-level construction of Mach-O headers and load commands.
• gaia-assembler: Acts as the primary Mach-O encapsulation backend for the assembler when targeting Apple platforms.