hlbc

Hashlink bytecode disassembler, analyzer, decompiler and assembler.

This crate is a library, see hlbc-cli for an actual program to use.

Features

• Parse the whole bytecode file or any bytecode element
• Display any bytecode element
• Restore all possible names
• Link elements between them (with manual references for flexibility)
• Link elements with their debug information
• Serialize bytecode back to bytes
• Decompiler to haxe source code for classes and functions
• Commandline interface to use the features of this library (hlbc-cli)

Planned features

• Integrate with the Haxe/Hashlink standard library to restore more names, exclude them from analysis and such
• Gui to render the callgraph in real time
• Gui to render instructions and decompiled code
• C API to integrate with other tools
• Text search engine to search for strings and names
• Assemble and inject bytecode or inject haxe source code directly

Changelog

See CHANGELOG.md.

Decompiler

The decompiler is currently incomplete (and will probably always be). See the wiki for examples of decompilation output.

Wiki

A wiki detailing the specifics of Hashlink bytecode is available here. The wiki also details the inner workings of haxe to hashlink compilation and decompilation.

Macros

There are 98 different bytecode instructions, there is no way I manually write code for it each time. Most of the code for these opcodes is generated through a proc macro (see hlbc-derive). The only time I needed to write 98 different branches was for the formatting used when displaying the instructions (src/fmt.rs).

Repository structure

• / : hlbc (lib)
• hlbc-derive/ : hlbc-derive, helper proc macros for hlbc
• hlbc-cli/ : CLI using hlbc
• data/ : Haxe source files to test the decompiler

Credits

Development of this crate wouldn't be possible without the hashlink source code. Some algorithms are directly derived from the original C code reading bytecode files.

Alternatives

This library is made in Rust, a C API is in the works which could permit using this lib in many other projects, but for now it is only Rust friendly.

Other alternatives include :

• Tinkering directly with the hashlink source code in C
• Using the in-progress dashlink made in Haxe but probably compilable to many other languages.

Notes about using Rust

Rust isn't a very good fit for this project, the whole bytecode is a large graph and self-references do not mix well with Rust. Further iterations of this crate could make use of an arena.