Alis Byte Code (Binary)

This document describes how Alis stores bytecode in binary format. The version described in this document is the latest, see table below.

The binary file contains these sections of bytecode in the this order:

1. magic number
2. version bytes
3. magic number postfix
4. metadata
5. labels
6. instruction & data

Magic Bytes

This part is always 17 bytes.

The first 7 bytes are to be:

ASCII:

ALISBC-

hexadecimal:

41 4C 49 53 42 43 2D

These are followed by 2 bytes, which are used to identify version information.

8 bytes after these bytes are ignored, these are the magic number postfix.

Version Identifying Bytes

Since all integers are stored in little endian, 0x0001 will be stored as: 01 00

Byte combinations not present in table above are reserved for future versions.

Metadata

An 8 byte (64 bit) unsigned integer used to store number of bytes in metadata, followed by the metadata.

Labels

An 8 byte (64 bit) unsigned integer stores the number of labels. This is followed by the labels.

A label is stored as:

1. CodeIndex - fixed length, 8 bytes
2. Name - variable length (char array).

Instructions & Data

An 8 byte (64 bit) unsigned integer stores the number of bytes used for storing instruction codes and their data. Following bytes are the code part of the ByteCode.

All integers are stored in little endian encoding