Introduction

AftonJIT - is a jit compiler for afton bytecode designed simple and flexibility. The current AftonJIT version is 0.1 ,the current format version is 1 and its magic number is 0xFFF. Afton V1 supports 5 instructions:

• push
• rem
• ret
• invoke(without arguments)
• dup

Also it supports functions, without arguments and variables

Now,AftonJIT as target supports only x86_64.

How to build

AftonJIT has some ways to built it. Here's they:

1. build production version by gcc or tcc:

make gcc

Or

make tcc

2. build debug version by gcc or tcc:

make gcc_debug

Or

make tcc_debug

3. Also you may to clean aftonjit binary by:

make clean

Opcodes

The next map displays mnemonic and its correspond opcode for writing real afton proggrams:

• push [ANY_NUMBER] : 0x00
• rem : 0x01
• ret [RET_VOID or RET_STACK or ANY_NUMBER] : 0x07
• invoke [FUNCTION_NAME_LEN] [FUNCTION_NAME] : 0x0B
• dup : 0x02
• fn [FUNCTION_NAME_LEN] [FUNCTION_NAME] [LOCALS_COUNT] [ARGUMENTS_COUNT] : 0x1F
• end : 0x5F
• end_prg : 0xFE

Here's:

1. RET_VOID is magic number notificates AftonJIT not return something from function
2. RET_STACK is magic number notificates AftonJIT return the latest value from stack
3. end is marker notificates AftonJIT scope of the current function is ended
4. end_prg is marker notificates AftonJIT the proggram code is ended

Tests

For testing something proggrams,you can execute like this:

make test

That command generates 4 test files and their names you may execute with ./aftonjit command

Dumping AftonJIT binary code

If you're in the debug mode,you may see the title like "Dumped XX bytes to jit_dump.bin". For seeing what AftonJIT generates based on your proggram,use the command below:

objdump -D -b binary -m i386:x86-64 jit_dump.bin   

You're seeing like this:

jit_dump.bin:     file format binary


Disassembly of section .data:

0000000000000000 <.data>:
   0:	55                   	push   %rbp
   1:	48 89 e5             	mov    %rsp,%rbp
   4:	58                   	pop    %rax
   5:	c9                   	leave
   6:	c3                   	ret