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#===- disassembler.py - Python LLVM Bindings -----------------*- python -*--===#
#
# The LLVM Compiler Infrastructure
#
# This file is distributed under the University of Illinois Open Source
# License. See LICENSE.TXT for details.
#
#===------------------------------------------------------------------------===#
from ctypes import CFUNCTYPE
from ctypes import POINTER
from ctypes import addressof
from ctypes import byref
from ctypes import c_byte
from ctypes import c_char_p
from ctypes import c_int
from ctypes import c_size_t
from ctypes import c_ubyte
from ctypes import c_uint64
from ctypes import c_void_p
from ctypes import cast
from .common import LLVMObject
from .common import c_object_p
from .common import get_library
__all__ = [
'Disassembler',
]
lib = get_library()
callbacks = {}
class Disassembler(LLVMObject):
"""Represents a disassembler instance.
Disassembler instances are tied to specific "triple," which must be defined
at creation time.
Disassembler instances can disassemble instructions from multiple sources.
"""
def __init__(self, triple):
"""Create a new disassembler instance.
The triple argument is the triple to create the disassembler for. This
is something like 'i386-apple-darwin9'.
"""
ptr = lib.LLVMCreateDisasm(c_char_p(triple), c_void_p(None), c_int(0),
callbacks['op_info'](0), callbacks['symbol_lookup'](0))
if not ptr.contents:
raise Exception('Could not obtain disassembler for triple: %s' %
triple)
LLVMObject.__init__(self, ptr, disposer=lib.LLVMDisasmDispose)
def get_instruction(self, source, pc=0):
"""Obtain the next instruction from an input source.
The input source should be a str or bytearray or something that
represents a sequence of bytes.
This function will start reading bytes from the beginning of the
source.
The pc argument specifies the address that the first byte is at.
This returns a 2-tuple of:
long number of bytes read. 0 if no instruction was read.
str representation of instruction. This will be the assembly that
represents the instruction.
"""
buf = cast(c_char_p(source), POINTER(c_ubyte))
out_str = cast((c_byte * 255)(), c_char_p)
result = lib.LLVMDisasmInstruction(self, buf, c_uint64(len(source)),
c_uint64(pc), out_str, 255)
return (result, out_str.value)
def get_instructions(self, source, pc=0):
"""Obtain multiple instructions from an input source.
This is like get_instruction() except it is a generator for all
instructions within the source. It starts at the beginning of the
source and reads instructions until no more can be read.
This generator returns 3-tuple of:
long address of instruction.
long size of instruction, in bytes.
str representation of instruction.
"""
source_bytes = c_char_p(source)
out_str = cast((c_byte * 255)(), c_char_p)
# This could probably be written cleaner. But, it does work.
buf = cast(source_bytes, POINTER(c_ubyte * len(source))).contents
offset = 0
address = pc
end_address = pc + len(source)
while address < end_address:
b = cast(addressof(buf) + offset, POINTER(c_ubyte))
result = lib.LLVMDisasmInstruction(self, b,
c_uint64(len(source) - offset), c_uint64(address),
out_str, 255)
if result == 0:
break
yield (address, result, out_str.value)
address += result
offset += result
def register_library(library):
library.LLVMCreateDisasm.argtypes = [c_char_p, c_void_p, c_int,
callbacks['op_info'], callbacks['symbol_lookup']]
library.LLVMCreateDisasm.restype = c_object_p
library.LLVMDisasmDispose.argtypes = [Disassembler]
library.LLVMDisasmInstruction.argtypes = [Disassembler, POINTER(c_ubyte),
c_uint64, c_uint64, c_char_p, c_size_t]
library.LLVMDisasmInstruction.restype = c_size_t
callbacks['op_info'] = CFUNCTYPE(c_int, c_void_p, c_uint64, c_uint64, c_uint64,
c_int, c_void_p)
callbacks['symbol_lookup'] = CFUNCTYPE(c_char_p, c_void_p, c_uint64,
POINTER(c_uint64), c_uint64,
POINTER(c_char_p))
register_library(lib)
|
