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Module formats

jvm_assembler

Module formats 

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Support for various JVM class file formats (binary, etc.)

§Formats Module

The formats module handles the translation between external representations (binary .class files, text .jasm files) and the internal JvmProgram model.

§Overview

This module is the I/O hub of the library. It provides specialized sub-modules for different JVM-related formats:

  • Class: Binary Java Class file format (JVMS Chapter 4).
  • JASM: Human-readable assembly language for JVM bytecode.

§Core Capabilities

§1. Java Class File Support (class)

  • Reading: Parse complex binary structures into a high-level IR.
  • Writing: Serialize the IR back to binary, handling constant pool generation and instruction encoding.
  • Viewing: Fast metadata access without full bytecode parsing.

§2. JASM Assembly Support (jasm)

  • Parsing: Convert .jasm text files into JvmProgram.
  • Generation: Disassemble a JvmProgram or binary .class file into readable .jasm source code.

§Unified Workflow

The library is designed to allow seamless conversion between formats:

// .class -> JvmProgram -> .jasm
let program = ClassReader::new(class_file, &config).read().result?;
let jasm_code = JasmWriter::new().write(&program)?;

// .jasm -> JvmProgram -> .class
let program = JasmParser::new(jasm_source).parse()?;
ClassWriter::new(&mut output_buffer).write(&program).result?;

§Error Handling

All format operations return GaiaDiagnostics<T>, which includes:

  • result: The successfully parsed/written object or a GaiaError.
  • diagnostics: A list of warnings or non-fatal errors encountered during the process.

Modules§

class
Class File Format
jasm