aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/python/cryptography/_cffi_src/utils.py
blob: 21ebf8a4675f58084bd2d408b69600c361a4b90c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
# This file is dual licensed under the terms of the Apache License, Version 
# 2.0, and the BSD License. See the LICENSE file in the root of this repository 
# for complete details. 
 
from __future__ import absolute_import, division, print_function 
 
import os
import sys 
from distutils.ccompiler import new_compiler 
from distutils.dist import Distribution 
 
from cffi import FFI 
 
 
# Load the cryptography __about__ to get the current package version
base_src = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
about = {}
with open(os.path.join(base_src, "cryptography", "__about__.py")) as f:
    exec (f.read(), about)


def build_ffi_for_binding(
    module_name,
    module_prefix,
    modules,
    libraries=[],
    extra_compile_args=[],
    extra_link_args=[],
):
    """ 
    Modules listed in ``modules`` should have the following attributes: 
 
    * ``INCLUDES``: A string containing C includes. 
    * ``TYPES``: A string containing C declarations for types. 
    * ``FUNCTIONS``: A string containing C declarations for functions & macros.
    * ``CUSTOMIZATIONS``: A string containing arbitrary top-level C code, this 
        can be used to do things like test for a define and provide an 
        alternate implementation based on that. 
    """ 
    types = [] 
    includes = [] 
    functions = [] 
    customizations = [] 
    for name in modules: 
        __import__(module_prefix + name) 
        module = sys.modules[module_prefix + name] 
 
        types.append(module.TYPES) 
        functions.append(module.FUNCTIONS) 
        includes.append(module.INCLUDES) 
        customizations.append(module.CUSTOMIZATIONS) 
 
    verify_source = "\n".join(includes + customizations)
    ffi = build_ffi( 
        module_name, 
        cdef_source="\n".join(types + functions),
        verify_source=verify_source, 
        libraries=libraries, 
        extra_compile_args=extra_compile_args, 
        extra_link_args=extra_link_args, 
    ) 
 
    return ffi 
 
 
def build_ffi(
    module_name,
    cdef_source,
    verify_source,
    libraries=[],
    extra_compile_args=[],
    extra_link_args=[],
):
    ffi = FFI() 
    # Always add the CRYPTOGRAPHY_PACKAGE_VERSION to the shared object
    cdef_source += "\nstatic const char *const CRYPTOGRAPHY_PACKAGE_VERSION;"
    verify_source += '\n#define CRYPTOGRAPHY_PACKAGE_VERSION "{}"'.format(
        about["__version__"]
    )
    ffi.cdef(cdef_source) 
    ffi.set_source( 
        module_name, 
        verify_source, 
        libraries=libraries, 
        extra_compile_args=extra_compile_args, 
        extra_link_args=extra_link_args, 
    ) 
    return ffi 
 
 
def extra_link_args(compiler_type): 
    if compiler_type == "msvc":
        # Enable NX and ASLR for Windows builds on MSVC. These are enabled by 
        # default on Python 3.3+ but not on 2.x. 
        return ["/NXCOMPAT", "/DYNAMICBASE"]
    else: 
        return [] 
 
 
def compiler_type(): 
    """ 
    Gets the compiler type from distutils. On Windows with MSVC it will be 
    "msvc". On macOS and linux it is "unix".
    """ 
    dist = Distribution() 
    dist.parse_config_files() 
    cmd = dist.get_command_obj("build")
    cmd.ensure_finalized() 
    compiler = new_compiler(compiler=cmd.compiler) 
    return compiler.compiler_type