def cast_int_addr(n):
    """Cast an address to a Python int
    
    This could be a Python integer or a CFFI pointer
    """
    if isinstance(n, (int, long)):
        return n
    try:
        import cffi
    except ImportError:
        pass
    else:
        # from pyzmq, this is an FFI void *
        ffi = cffi.FFI()
        if isinstance(n, ffi.CData):
            return int(ffi.cast("size_t", n))
    
    raise ValueError("Cannot cast %r to int" % n) 

def __init__(self, on_device='cpu', blank_label=0):
        libpath = get_ctc_lib()
        self.ffi = FFI()
        self.ffi.cdef(ctc_header())
        self.ctclib = self.ffi.dlopen(libpath)

        supported_devices = ['cpu', 'gpu']
        if on_device not in supported_devices:
            print("the requested device {} is not supported".format(
                on_device), file=sys.stderr)
            sys.exit(1)
        assign_device = 0 if on_device is 'cpu' else 1

        self.options = self.ffi.new('ctcOptions*',
                                    {"loc": assign_device,
                                     "blank_label": blank_label})[0]
        self.size_in_bytes = self.ffi.new("size_t*")
        self.nout = None
        self.bsz = None 

def test_callback_onerror(self):
        ffi = FFI(backend=self.Backend())
        seen = []
        def oops(*args):
            seen.append(args)
        def otherfunc():
            raise LookupError
        def cb(n):
            otherfunc()
        a = ffi.callback("int(*)(int)", cb, error=42, onerror=oops)
        res = a(234)
        assert res == 42
        assert len(seen) == 1
        exc, val, tb = seen[0]
        assert exc is LookupError
        assert isinstance(val, LookupError)
        assert tb.tb_frame.f_code.co_name == 'cb'
        assert tb.tb_frame.f_locals['n'] == 234 

def test_ffi_new_allocator_4(self):
        ffi = FFI(backend=self.Backend())
        py.test.raises(TypeError, ffi.new_allocator, free=lambda x: None)
        #
        def myalloc2(size):
            raise LookupError
        alloc2 = ffi.new_allocator(myalloc2)
        py.test.raises(LookupError, alloc2, "int[5]")
        #
        def myalloc3(size):
            return 42
        alloc3 = ffi.new_allocator(myalloc3)
        e = py.test.raises(TypeError, alloc3, "int[5]")
        assert str(e.value) == "alloc() must return a cdata object (got int)"
        #
        def myalloc4(size):
            return ffi.cast("int", 42)
        alloc4 = ffi.new_allocator(myalloc4)
        e = py.test.raises(TypeError, alloc4, "int[5]")
        assert str(e.value) == "alloc() must return a cdata pointer, not 'int'"
        #
        def myalloc5(size):
            return ffi.NULL
        alloc5 = ffi.new_allocator(myalloc5)
        py.test.raises(MemoryError, alloc5, "int[5]") 

def test_callback_returning_void(self):
        ffi = FFI(backend=self.Backend())
        for returnvalue in [None, 42]:
            def cb():
                return returnvalue
            fptr = ffi.callback("void(*)(void)", cb)
            old_stderr = sys.stderr
            try:
                sys.stderr = StringIO()
                returned = fptr()
                printed = sys.stderr.getvalue()
            finally:
                sys.stderr = old_stderr
            assert returned is None
            if returnvalue is None:
                assert printed == ''
            else:
                assert "None" in printed 

def test_fputs_custom_FILE(self):
        if self.Backend is CTypesBackend:
            py.test.skip("FILE not supported with the ctypes backend")
        filename = str(udir.join('fputs_custom_FILE'))
        ffi = FFI(backend=self.Backend())
        ffi.cdef("int fputs(const char *, FILE *);")
        C = ffi.dlopen(None)
        with open(filename, 'wb') as f:
            f.write(b'[')
            C.fputs(b"hello from custom file", f)
            f.write(b'][')
            C.fputs(b"some more output", f)
            f.write(b']')
        with open(filename, 'rb') as f:
            res = f.read()
        assert res == b'[hello from custom file][some more output]' 

def test_free_callback_cycle(self):
        if self.Backend is CTypesBackend:
            py.test.skip("seems to fail with the ctypes backend on windows")
        import weakref
        def make_callback(data):
            container = [data]
            callback = ffi.callback('int()', lambda: len(container))
            container.append(callback)
            # Ref cycle: callback -> lambda (closure) -> container -> callback
            return callback

        class Data(object):
            pass
        ffi = FFI(backend=self.Backend())
        data = Data()
        callback = make_callback(data)
        wr = weakref.ref(data)
        del callback, data
        for i in range(3):
            if wr() is not None:
                import gc; gc.collect()
        assert wr() is None    # 'data' does not leak 

def test_setting_errno(self):
        if self.module is None:
            py.test.skip("fix the auto-generation of the tiny test lib")
        if sys.platform == 'win32':
            py.test.skip("fails, errno at multiple addresses")
        if self.Backend is CTypesBackend and '__pypy__' in sys.modules:
            py.test.skip("XXX errno issue with ctypes on pypy?")
        ffi = FFI(backend=self.Backend())
        ffi.cdef("""
            int test_setting_errno(void);
        """)
        ownlib = ffi.dlopen(self.module)
        ffi.errno = 42
        res = ownlib.test_setting_errno()
        assert res == 42
        assert ffi.errno == 42 

def test_my_array_7(self):
        if self.module is None:
            py.test.skip("fix the auto-generation of the tiny test lib")
        ffi = FFI(backend=self.Backend())
        ffi.cdef("""
            int my_array[7];
        """)
        ownlib = ffi.dlopen(self.module)
        for i in range(7):
            assert ownlib.my_array[i] == i
        assert len(ownlib.my_array) == 7
        if self.Backend is CTypesBackend:
            py.test.skip("not supported by the ctypes backend")
        ownlib.my_array = list(range(10, 17))
        for i in range(7):
            assert ownlib.my_array[i] == 10 + i
        ownlib.my_array = list(range(7))
        for i in range(7):
            assert ownlib.my_array[i] == i 

def test_my_array_no_length(self):
        if self.module is None:
            py.test.skip("fix the auto-generation of the tiny test lib")
        if self.Backend is CTypesBackend:
            py.test.skip("not supported by the ctypes backend")
        ffi = FFI(backend=self.Backend())
        ffi.cdef("""
            int my_array[];
        """)
        ownlib = ffi.dlopen(self.module)
        for i in range(7):
            assert ownlib.my_array[i] == i
        py.test.raises(TypeError, len, ownlib.my_array)
        ownlib.my_array = list(range(10, 17))
        for i in range(7):
            assert ownlib.my_array[i] == 10 + i
        ownlib.my_array = list(range(7))
        for i in range(7):
            assert ownlib.my_array[i] == i 

def test_keepalive_lib(self):
        if self.module is None:
            py.test.skip("fix the auto-generation of the tiny test lib")
        ffi = FFI(backend=self.Backend())
        ffi.cdef("""
            int test_getting_errno(void);
        """)
        ownlib = ffi.dlopen(self.module)
        ffi_r = weakref.ref(ffi)
        ownlib_r = weakref.ref(ownlib)
        func = ownlib.test_getting_errno
        del ffi
        import gc; gc.collect()       # ownlib stays alive
        assert ownlib_r() is not None
        assert ffi_r() is not None    # kept alive by ownlib
        res = func()
        assert res == -1 

def test_remove_comments():
    ffi = FFI(backend=FakeBackend())
    ffi.cdef("""
        double /*comment here*/ sin   // blah blah
        /* multi-
           line-
           //comment */  (
        // foo
        double // bar      /* <- ignored, because it's in a comment itself
        x, double/*several*//*comment*/y) /*on the same line*/
        ;
    """)
    m = ffi.dlopen(lib_m)
    func = m.sin
    assert func.name == 'sin'
    assert func.BType == '<func (<double>, <double>), <double>, False>' 

def test_remove_line_continuation_comments():
    ffi = FFI(backend=FakeBackend())
    ffi.cdef("""
        double // blah \\
                  more comments
        x(void);
        double // blah\\\\
        y(void);
        double // blah\\ \
                  etc
        z(void);
    """)
    m = ffi.dlopen(lib_m)
    m.x
    m.y
    m.z 

def test__is_constant_globalvar():
    for input, expected_output in [
        ("int a;",          False),
        ("const int a;",    True),
        ("int *a;",         False),
        ("const int *a;",   False),
        ("int const *a;",   False),
        ("int *const a;",   True),
        ("int a[5];",       False),
        ("const int a[5];", False),
        ("int *a[5];",      False),
        ("const int *a[5];", False),
        ("int const *a[5];", False),
        ("int *const a[5];", False),
        ("int a[5][6];",       False),
        ("const int a[5][6];", False),
        ]:
        ffi = FFI()
        ffi.cdef(input)
        declarations = ffi._parser._declarations
        assert ('constant a' in declarations) == expected_output
        assert ('variable a' in declarations) == (not expected_output) 

def _import_cffi():
    global ffi, CData

    if ffi is not None:
        return

    try:
        import cffi
        ffi = cffi.FFI()
        CData = ffi.CData
    except ImportError:
        ffi = False 

def _getffi():
  string = pkgutil.get_data(__name__, 'libmyo.h').decode('utf8')
  string = string.replace('\r\n', '\n')
  # Remove stuff that cffi can not parse.
  string = re.sub('^\s*#.*$', '', string, flags=re.M)
  string = string.replace('LIBMYO_EXPORT', '')
  string = string.replace('extern "C" {', '')
  string = string.replace('} // extern "C"', '')

  ffi = cffi.FFI()
  ffi.cdef(string)
  return ffi 

def zmq_version_info():
    ffi_check = FFI()
    ffi_check.cdef('void zmq_version(int *major, int *minor, int *patch);')
    C_check_version = ffi_check.verify('#include <zmq.h>',
                                            libraries=['c', 'zmq'])
    major = ffi.new('int*')
    minor = ffi.new('int*')
    patch = ffi.new('int*')

    C_check_version.zmq_version(major, minor, patch)

    return (int(major[0]), int(minor[0]), int(patch[0])) 

def __init__(self, stride, padding, dilation, bias=True):
        super(DepthconvFunction, self).__init__()
        self.stride = stride
        self.padding = padding
        self.dilation = dilation
        ffi_=cffi.FFI()
        self.null = ffi_.NULL
        self.bias = bias 

def check_lib_python_found(tmpdir):
    global _link_error
    if _link_error == '?':
        ffi = cffi.FFI()
        kwds = {}
        ffi._apply_embedding_fix(kwds)
        ffi.set_source("_test_lib_python_found", "", **kwds)
        try:
            ffi.compile(tmpdir=tmpdir, verbose=True)
        except cffi.VerificationError as e:
            _link_error = e
        else:
            _link_error = None
    if _link_error:
        py.test.skip(str(_link_error)) 

def test_not_supported_bitfield_in_result(self):
        ffi = FFI(backend=self.Backend())
        ffi.cdef("struct foo_s { int a,b,c,d,e; int x:1; };")
        e = py.test.raises(NotImplementedError, ffi.callback,
                           "struct foo_s foo(void)", lambda: 42)
        assert str(e.value) == ("struct foo_s(*)(): "
            "callback with unsupported argument or return type or with '...'") 

def test_inspecttype(self):
        ffi = FFI(backend=self.Backend())
        assert ffi.typeof("long").kind == "primitive"
        assert ffi.typeof("long(*)(long, long**, ...)").cname == (
            "long(*)(long, long * *, ...)")
        assert ffi.typeof("long(*)(long, long**, ...)").ellipsis is True 

def test_new_handle(self):
        ffi = FFI(backend=self.Backend())
        o = [2, 3, 4]
        p = ffi.new_handle(o)
        assert ffi.typeof(p) == ffi.typeof("void *")
        assert ffi.from_handle(p) is o
        assert ffi.from_handle(ffi.cast("char *", p)) is o
        py.test.raises(RuntimeError, ffi.from_handle, ffi.NULL) 

def test_ffi_new_allocator_3(self):
        ffi = FFI(backend=self.Backend())
        seen = []
        def myalloc(size):
            seen.append(size)
            return ffi.new("char[]", b"X" * size)
        alloc1 = ffi.new_allocator(myalloc)    # no 'free'
        p1 = alloc1("int[10]")
        assert seen == [40]
        assert ffi.typeof(p1) == ffi.typeof("int[10]")
        assert ffi.sizeof(p1) == 40
        assert p1[5] == 0 

def test_bitfield_anonymous_no_align(self):
        L = FFI().alignof("long long")
        self.check("char y; int :1;", 0, 1, 2)
        self.check("char x; int z:1; char y;", 2, 4, 4)
        self.check("char x; int  :1; char y;", 2, 1, 3)
        self.check("char x; long long z:48; char y;", 7, L, 8)
        self.check("char x; long long  :48; char y;", 7, 1, 8)
        self.check("char x; long long z:56; char y;", 8, L, 8 + L)
        self.check("char x; long long  :56; char y;", 8, 1, 9)
        self.check("char x; long long z:57; char y;", L + 8, L, L + 8 + L)
        self.check("char x; long long  :57; char y;", L + 8, 1, L + 9) 

def test_bitfield_anonymous_align_arm(self):
        L = FFI().alignof("long long")
        self.check("char y; int :1;", 0, 4, 4)
        self.check("char x; int z:1; char y;", 2, 4, 4)
        self.check("char x; int  :1; char y;", 2, 4, 4)
        self.check("char x; long long z:48; char y;", 7, L, 8)
        self.check("char x; long long  :48; char y;", 7, 8, 8)
        self.check("char x; long long z:56; char y;", 8, L, 8 + L)
        self.check("char x; long long  :56; char y;", 8, L, 8 + L)
        self.check("char x; long long z:57; char y;", L + 8, L, L + 8 + L)
        self.check("char x; long long  :57; char y;", L + 8, L, L + 8 + L) 

def test_bitfield_zero_arm(self):
        L = FFI().alignof("long long")
        self.check("char y; int :0;", 0, 4, 4)
        self.check("char x; int :0; char y;", 4, 4, 8)
        self.check("char x; int :0; int :0; char y;", 4, 4, 8)
        self.check("char x; long long :0; char y;", L, 8, L + 8)
        self.check("short x, y; int :0; int :0;", 2, 4, 4)
        self.check("char x; int :0; short b:1; char y;", 5, 4, 8)
        self.check("int a:1; int :0; int b:1; char y;", 5, 4, 8) 

def test_error_cases(self):
        ffi = FFI()
        py.test.raises(TypeError,
            'ffi.cdef("struct s1 { float x:1; };"); ffi.new("struct s1 *")')
        py.test.raises(TypeError,
            'ffi.cdef("struct s2 { char x:0; };"); ffi.new("struct s2 *")')
        py.test.raises(TypeError,
            'ffi.cdef("struct s3 { char x:9; };"); ffi.new("struct s3 *")') 

def test_struct_with_typedef(self):
        ffi = FFI()
        ffi.cdef("typedef struct { float x; } foo_t;")
        p = ffi.new("foo_t *", [5.2])
        assert repr(p).startswith("<cdata 'foo_t *' ") 

def test_struct_array_no_length(self):
        ffi = FFI()
        ffi.cdef("struct foo_s { int x; int a[]; };")
        p = ffi.new("struct foo_s *", [100, [200, 300, 400]])
        assert p.x == 100
        assert ffi.typeof(p.a) is ffi.typeof("int *")   # no length available
        assert p.a[0] == 200
        assert p.a[1] == 300
        assert p.a[2] == 400 

def test_getwinerror(self):
        ffi = FFI()
        code, message = ffi.getwinerror(1155)
        assert code == 1155
        assert message == ("No application is associated with the "
                           "specified file for this operation")
        ffi.cdef("void SetLastError(int);")
        lib = ffi.dlopen("Kernel32.dll")
        lib.SetLastError(2)
        code, message = ffi.getwinerror()
        assert code == 2
        assert message == "The system cannot find the file specified"
        code, message = ffi.getwinerror(-1)
        assert code == 2
        assert message == "The system cannot find the file specified"