Python bindings for GNU Lightning JIT
Project description
Lyn provides Python bindings for GNU Lightning, the light-weight just-in-time (JIT) compiler that translates to native machine code.
The code is hosted on https://github.com/cslarsen/lyn/ and is installable from https://pypi.python.org/pypi/lyn/ (although I currently don’t update PyPi quite often).
“Lyn” is the Norwegian word for “lightning”.
NOTE: This project is currently in extremely early stages!
Status
As mentioned above, Lyn is fledgling: I’ve just spent a few hours on it, so almost nothing is supported and — in particular — I’ve only targeted x86-64 opcodes just yet. Some tests are also failing: Min and max 64-bit numbers don’t seem to pass through correctly, so I’m currently working on fixing that issue first.
In spite of this, I’ve managed to create a really simple program in Python that is JIT-compiled to native x86-64 machine code: A glorious function that returns the value of 123! Here’s the code:
from lyn import Lightning, Register with Lightning().state() as jit: jit.prolog() # Actual code jit.movi(Register.v0, 123) jit.retr(Register.v0) # Compile to native code and wrap in a Python-callable function func = jit.emit_function(Lightning.word_t) print("Function returned %s and that is %s!" % ( func(), "correct" if func() == 123 else "incorrect"))
Also, I’ve not been able to compile GNU Lightning with disassembly support, so I just used Capstone instead (install with pip install capstone):
from lyn import * import capstone import ctypes lib = Lightning() jit = lib.new_state() # A function that returns one more than its integer input start = jit.note() jit.prolog() arg = jit.arg() jit.getarg(Register.r0, arg) jit.addi(Register.r0, Register.r0, 1) jit.retr(Register.r0) jit.epilog() end = jit.note() # Bind function to Python: returns a word (native integer), takes a word. incr = jit.emit_function(lib.word_t, [lib.word_t]) # Sanity check assert(incr(1234) == 1235) # This part should be obvious to C programmers: We need to read data from raw # memory in to a Python iterable. length = (jit.address(end) - jit.address(start)).value codebuf = ctypes.create_string_buffer(length) ctypes.memmove(codebuf, ctypes.c_char_p(incr.address.value), length) print("Compiled %d bytes starting at 0x%x" % (length, incr.address)) def hexbytes(b): return "".join(map(lambda x: hex(x)[2:] + " ", b)) # Capstone is smart enough to stop at the first RET-like instruction. md = capstone.Cs(capstone.CS_ARCH_X86, capstone.CS_MODE_64) md.syntax = capstone.CS_OPT_SYNTAX_ATT # Change to Intel syntax if you want for i in md.disasm(codebuf, incr.address.value): print("0x%x %-15s%s %s" % (i.address, hexbytes(i.bytes), i.mnemonic, i.op_str)) raw = "".join(map(lambda x: "\\x%02x" % x, map(ord, codebuf))) print("\nRaw bytes: %s" % raw)
This outputs:
Compiled 34 bytes starting at 0x10acf4000 0x10acf4000 48 83 ec 30 subq $0x30, %rsp 0x10acf4004 48 89 2c 24 movq %rbp, (%rsp) 0x10acf4008 48 89 e5 movq %rsp, %rbp 0x10acf400b 48 83 ec 18 subq $0x18, %rsp 0x10acf400f 48 89 f8 movq %rdi, %rax 0x10acf4012 48 83 c0 1 addq $1, %rax 0x10acf4016 48 89 ec movq %rbp, %rsp 0x10acf4019 48 8b 2c 24 movq (%rsp), %rbp 0x10acf401d 48 83 c4 30 addq $0x30, %rsp 0x10acf4021 c3 retq Raw bytes: \x48\x83\xec\x30\x48\x89\x2c\x24[...]
I’m using ctypes for creating the bindings, which comes with some challenges: GNU Lightning is written in C, and relies heavily on compile-time macros that define machine specific opcodes, register values and so on.
Because of this, it would be more natural to simply create bindings through a C extension. On the other hand, though, ctypes makes it possible to ship Lyn as a platform independent, pure Python source. I’ll chew on this for a while, and we’ll see what happens.
Installation
Either:
$ pip install lyn
or:
$ python setup.py install
Requirements
You need GNU Lightning version 2.1.0, built as a shared library.
Remember to configure GNU Lightning with the option --enable-shared. To use the disassembler, you should also add --enable-disassembler.
Project details
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
Source Distribution
Built Distribution
File details
Details for the file lyn-0.0.4.tar.gz
.
File metadata
- Download URL: lyn-0.0.4.tar.gz
- Upload date:
- Size: 18.6 kB
- Tags: Source
- Uploaded using Trusted Publishing? No
File hashes
Algorithm | Hash digest | |
---|---|---|
SHA256 |
d41fd68150c4c68ee54c51ecce7c5d62f96a65a4d98180da50e0c56fc970a89a
|
|
MD5 |
7264be668fb372875e5ccf6710d1e657
|
|
BLAKE2b-256 |
c765dc6b5efb99272b297f81bdb086c44d3f259f063ab55bbc60e137a238082d
|
File details
Details for the file lyn-0.0.4-py2.py3-none-any.whl
.
File metadata
- Download URL: lyn-0.0.4-py2.py3-none-any.whl
- Upload date:
- Size: 12.2 kB
- Tags: Python 2, Python 3
- Uploaded using Trusted Publishing? No
File hashes
Algorithm | Hash digest | |
---|---|---|
SHA256 |
accb6407a6ce3b5147f93b2cd29afebca262931f767578ba9abd253c7e44a8d8
|
|
MD5 |
3ebaff71d994e27740dfddb3c688a402
|
|
BLAKE2b-256 |
9ada6b89623375ae52d8c692891ebe73738e14a417bc9d40ce03e2063cae9860
|