Oak JASM Parser

High-performance incremental JASM parser for the oak ecosystem with flexible configuration, optimized for assembly language analysis and JVM bytecode generation.

🎯 Overview

Oak JASM is a robust parser for Java ASseMbler (JASM), designed to handle complete JASM syntax including modern assembly features and JVM bytecode instructions. Built on the solid foundation of oak-core, it provides both high-level convenience and detailed AST generation for JASM analysis and tooling.

✨ Features

• Complete JASM Syntax: Supports all JASM features including class definitions, methods, and bytecode instructions
• JVM Bytecode Support: Handles all JVM bytecode instructions and type descriptors
• Full AST Generation: Generates comprehensive Abstract Syntax Trees
• Lexer Support: Built-in tokenization with proper span information
• Error Recovery: Graceful handling of syntax errors with detailed diagnostics

🚀 Quick Start

Basic example:

use oak_core::{Parser, SourceText, parser::session::ParseSession};
use oak_jasm::{JasmParser, JasmLanguage};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut session = ParseSession::<JasmLanguage>::default();
    let parser = JasmParser::new();
    let source = SourceText::new(r#"
.class public Hello
.super java/lang/Object

.method public <init>()V
    aload_0
    invokespecial java/lang/Object/<init>()V
    return
.end method

.method public static main([Ljava/lang/String;)V
    .limit stack 2
    getstatic java/lang/System/out Ljava/io/PrintStream;
    ldc "Hello, JASM!"
    invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V
    return
.end method
.end class
    "#);
    
    let result = parser.parse(&source, &[], &mut session);
    println!("Parsed JASM class successfully.");
    Ok(())
}

📋 Parsing Examples

Class Definition Parsing

use oak_core::{Parser, SourceText, parser::session::ParseSession};
use oak_jasm::{JasmParser, JasmLanguage};

let mut session = ParseSession::<JasmLanguage>::default();
let parser = JasmParser::new();
let source = SourceText::new(r#"
.class public Calculator
.super java/lang/Object

.field private result I

.method public <init>()V
    aload_0
    invokespecial java/lang/Object/<init>()V
    aload_0
    iconst_0
    putfield Calculator/result I
    return
.end method

.method public add(I)V
    aload_0
    dup
    getfield Calculator/result I
    iload_1
    iadd
    putfield Calculator/result I
    return
.end method
.end class
"#);

let result = parser.parse(&source, &[], &mut session);
println!("Parsed JASM class with fields and methods successfully.");

Method with Control Flow

use oak_core::{Parser, SourceText, parser::session::ParseSession};
use oak_jasm::{JasmParser, JasmLanguage};

let mut session = ParseSession::<JasmLanguage>::default();
let parser = JasmParser::new();
let source = SourceText::new(r#"
.class public LoopExample
.super java/lang/Object

.method public static count(I)V
    .limit locals 2
    iconst_0
    istore_1
Loop:
    iload_1
    iload_0
    if_icmpge End
    
    getstatic java/lang/System/out Ljava/io/PrintStream;
    iload_1
    invokevirtual java/io/PrintStream/println(I)V
    
    iinc 1 1
    goto Loop
End:
    return
.end method
.end class
"#);

let result = parser.parse(&source, &[], &mut session);
println!("Parsed JASM with control flow successfully.");

🔧 Advanced Features

Token-Level Parsing

use oak_core::{Parser, SourceText, parser::session::ParseSession};
use oak_jasm::{JasmParser, JasmLanguage};

let mut session = ParseSession::<JasmLanguage>::default();
let parser = JasmParser::new();
let source = SourceText::new(".class public MyClass");
let result = parser.parse(&source, &[], &mut session);
println!("Token parsing completed.");

Error Handling

use oak_core::{Parser, SourceText, parser::session::ParseSession};
use oak_jasm::{JasmParser, JasmLanguage};

let mut session = ParseSession::<JasmLanguage>::default();
let parser = JasmParser::new();
let source = SourceText::new(r#"
.class public Broken
# Missing super class or methods
"#);

let result = parser.parse(&source, &[], &mut session);
if let Some(errors) = result.result.err() {
    println!("Parse errors found: {:?}", errors);
} else {
    println!("Parsed successfully.");
}

🏗️ AST Structure

The parser generates a comprehensive AST with the following main structures:

• Class: JASM class definitions with access modifiers and inheritance
• Field: Field definitions with types and access modifiers
• Method: Method definitions with signatures and bytecode instructions
• Instruction: JVM bytecode instructions with operands
• Constant: Constant pool entries for strings, numbers, and references

📊 Performance

• Streaming: Parse large JASM files without loading entirely into memory
• Incremental: Re-parse only changed sections
• Memory Efficient: Smart AST node allocation
• Fast Recovery: Quick error recovery for better IDE integration

🔗 Integration

Oak-jasm integrates seamlessly with:

• Bytecode Analysis: Security analysis and optimization of JVM bytecode
• Code Generation: Generating bytecode from high-level languages
• IDE Support: Language server protocol compatibility for assembly languages
• Debugging Tools: Debuggers and profilers for JVM applications
• Documentation: Generating documentation from assembly code

📚 Examples

Check out the examples directory for comprehensive examples:

• Complete JASM class parsing
• Method and instruction analysis
• Control flow and exception handling
• Integration with development workflows

🤝 Contributing

Contributions are welcome!

Please feel free to submit pull requests at the project repository or open issues.