126 lines
3.8 KiB
Python
126 lines
3.8 KiB
Python
#===- common.py - Python LLVM Bindings -----------------------*- python -*--===#
|
|
#
|
|
# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
# See https://llvm.org/LICENSE.txt for license information.
|
|
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
#
|
|
#===------------------------------------------------------------------------===#
|
|
|
|
from ctypes import POINTER
|
|
from ctypes import c_void_p
|
|
from ctypes import cdll
|
|
|
|
import ctypes.util
|
|
import platform
|
|
|
|
# LLVM_VERSION: sync with PACKAGE_VERSION in CMakeLists.txt
|
|
# but leave out the 'svn' suffix.
|
|
LLVM_VERSION = '10.0.0'
|
|
|
|
__all__ = [
|
|
'c_object_p',
|
|
'get_library',
|
|
]
|
|
|
|
c_object_p = POINTER(c_void_p)
|
|
|
|
class LLVMObject(object):
|
|
"""Base class for objects that are backed by an LLVM data structure.
|
|
|
|
This class should never be instantiated outside of this package.
|
|
"""
|
|
def __init__(self, ptr, ownable=True, disposer=None):
|
|
assert isinstance(ptr, c_object_p)
|
|
|
|
self._ptr = self._as_parameter_ = ptr
|
|
|
|
self._self_owned = True
|
|
self._ownable = ownable
|
|
self._disposer = disposer
|
|
|
|
self._owned_objects = []
|
|
|
|
def take_ownership(self, obj):
|
|
"""Take ownership of another object.
|
|
|
|
When you take ownership of another object, you are responsible for
|
|
destroying that object. In addition, a reference to that object is
|
|
placed inside this object so the Python garbage collector will not
|
|
collect the object while it is still alive in libLLVM.
|
|
|
|
This method should likely only be called from within modules inside
|
|
this package.
|
|
"""
|
|
assert isinstance(obj, LLVMObject)
|
|
|
|
self._owned_objects.append(obj)
|
|
obj._self_owned = False
|
|
|
|
def from_param(self):
|
|
"""ctypes function that converts this object to a function parameter."""
|
|
return self._as_parameter_
|
|
|
|
def __del__(self):
|
|
if not hasattr(self, '_self_owned') or not hasattr(self, '_disposer'):
|
|
return
|
|
|
|
if self._self_owned and self._disposer:
|
|
self._disposer(self)
|
|
|
|
class CachedProperty(object):
|
|
"""Decorator that caches the result of a property lookup.
|
|
|
|
This is a useful replacement for @property. It is recommended to use this
|
|
decorator on properties that invoke C API calls for which the result of the
|
|
call will be idempotent.
|
|
"""
|
|
def __init__(self, wrapped):
|
|
self.wrapped = wrapped
|
|
try:
|
|
self.__doc__ = wrapped.__doc__
|
|
except: # pragma: no cover
|
|
pass
|
|
|
|
def __get__(self, instance, instance_type=None):
|
|
if instance is None:
|
|
return self
|
|
|
|
value = self.wrapped(instance)
|
|
setattr(instance, self.wrapped.__name__, value)
|
|
|
|
return value
|
|
|
|
def get_library():
|
|
"""Obtain a reference to the llvm library."""
|
|
|
|
# On Linux, ctypes.cdll.LoadLibrary() respects LD_LIBRARY_PATH
|
|
# while ctypes.util.find_library() doesn't.
|
|
# See http://docs.python.org/2/library/ctypes.html#finding-shared-libraries
|
|
#
|
|
# To make it possible to run the unit tests without installing the LLVM shared
|
|
# library into a default linker search path. Always Try ctypes.cdll.LoadLibrary()
|
|
# with all possible library names first, then try ctypes.util.find_library().
|
|
|
|
names = ['LLVM-' + LLVM_VERSION, 'LLVM-' + LLVM_VERSION + 'svn']
|
|
t = platform.system()
|
|
if t == 'Darwin':
|
|
pfx, ext = 'lib', '.dylib'
|
|
elif t == 'Windows':
|
|
pfx, ext = '', '.dll'
|
|
else:
|
|
pfx, ext = 'lib', '.so'
|
|
|
|
for i in names:
|
|
try:
|
|
lib = cdll.LoadLibrary(pfx + i + ext)
|
|
except OSError:
|
|
pass
|
|
else:
|
|
return lib
|
|
|
|
for i in names:
|
|
t = ctypes.util.find_library(i)
|
|
if t:
|
|
return cdll.LoadLibrary(t)
|
|
raise Exception('LLVM shared library not found!')
|