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authorS. Solomon Darnell2025-03-28 21:52:21 -0500
committerS. Solomon Darnell2025-03-28 21:52:21 -0500
commit4a52a71956a8d46fcb7294ac71734504bb09bcc2 (patch)
treeee3dc5af3b6313e921cd920906356f5d4febc4ed /.venv/lib/python3.12/site-packages/cffi/vengine_cpy.py
parentcc961e04ba734dd72309fb548a2f97d67d578813 (diff)
downloadgn-ai-4a52a71956a8d46fcb7294ac71734504bb09bcc2.tar.gz
two version of R2R are here HEAD master
Diffstat (limited to '.venv/lib/python3.12/site-packages/cffi/vengine_cpy.py')
-rw-r--r--.venv/lib/python3.12/site-packages/cffi/vengine_cpy.py1084
1 files changed, 1084 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/cffi/vengine_cpy.py b/.venv/lib/python3.12/site-packages/cffi/vengine_cpy.py
new file mode 100644
index 00000000..eb0b6f70
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/cffi/vengine_cpy.py
@@ -0,0 +1,1084 @@
+#
+# DEPRECATED: implementation for ffi.verify()
+#
+import sys
+from . import model
+from .error import VerificationError
+from . import _imp_emulation as imp
+
+
+class VCPythonEngine(object):
+    _class_key = 'x'
+    _gen_python_module = True
+
+    def __init__(self, verifier):
+        self.verifier = verifier
+        self.ffi = verifier.ffi
+        self._struct_pending_verification = {}
+        self._types_of_builtin_functions = {}
+
+    def patch_extension_kwds(self, kwds):
+        pass
+
+    def find_module(self, module_name, path, so_suffixes):
+        try:
+            f, filename, descr = imp.find_module(module_name, path)
+        except ImportError:
+            return None
+        if f is not None:
+            f.close()
+        # Note that after a setuptools installation, there are both .py
+        # and .so files with the same basename.  The code here relies on
+        # imp.find_module() locating the .so in priority.
+        if descr[0] not in so_suffixes:
+            return None
+        return filename
+
+    def collect_types(self):
+        self._typesdict = {}
+        self._generate("collecttype")
+
+    def _prnt(self, what=''):
+        self._f.write(what + '\n')
+
+    def _gettypenum(self, type):
+        # a KeyError here is a bug.  please report it! :-)
+        return self._typesdict[type]
+
+    def _do_collect_type(self, tp):
+        if ((not isinstance(tp, model.PrimitiveType)
+             or tp.name == 'long double')
+                and tp not in self._typesdict):
+            num = len(self._typesdict)
+            self._typesdict[tp] = num
+
+    def write_source_to_f(self):
+        self.collect_types()
+        #
+        # The new module will have a _cffi_setup() function that receives
+        # objects from the ffi world, and that calls some setup code in
+        # the module.  This setup code is split in several independent
+        # functions, e.g. one per constant.  The functions are "chained"
+        # by ending in a tail call to each other.
+        #
+        # This is further split in two chained lists, depending on if we
+        # can do it at import-time or if we must wait for _cffi_setup() to
+        # provide us with the <ctype> objects.  This is needed because we
+        # need the values of the enum constants in order to build the
+        # <ctype 'enum'> that we may have to pass to _cffi_setup().
+        #
+        # The following two 'chained_list_constants' items contains
+        # the head of these two chained lists, as a string that gives the
+        # call to do, if any.
+        self._chained_list_constants = ['((void)lib,0)', '((void)lib,0)']
+        #
+        prnt = self._prnt
+        # first paste some standard set of lines that are mostly '#define'
+        prnt(cffimod_header)
+        prnt()
+        # then paste the C source given by the user, verbatim.
+        prnt(self.verifier.preamble)
+        prnt()
+        #
+        # call generate_cpy_xxx_decl(), for every xxx found from
+        # ffi._parser._declarations.  This generates all the functions.
+        self._generate("decl")
+        #
+        # implement the function _cffi_setup_custom() as calling the
+        # head of the chained list.
+        self._generate_setup_custom()
+        prnt()
+        #
+        # produce the method table, including the entries for the
+        # generated Python->C function wrappers, which are done
+        # by generate_cpy_function_method().
+        prnt('static PyMethodDef _cffi_methods[] = {')
+        self._generate("method")
+        prnt('  {"_cffi_setup", _cffi_setup, METH_VARARGS, NULL},')
+        prnt('  {NULL, NULL, 0, NULL}    /* Sentinel */')
+        prnt('};')
+        prnt()
+        #
+        # standard init.
+        modname = self.verifier.get_module_name()
+        constants = self._chained_list_constants[False]
+        prnt('#if PY_MAJOR_VERSION >= 3')
+        prnt()
+        prnt('static struct PyModuleDef _cffi_module_def = {')
+        prnt('  PyModuleDef_HEAD_INIT,')
+        prnt('  "%s",' % modname)
+        prnt('  NULL,')
+        prnt('  -1,')
+        prnt('  _cffi_methods,')
+        prnt('  NULL, NULL, NULL, NULL')
+        prnt('};')
+        prnt()
+        prnt('PyMODINIT_FUNC')
+        prnt('PyInit_%s(void)' % modname)
+        prnt('{')
+        prnt('  PyObject *lib;')
+        prnt('  lib = PyModule_Create(&_cffi_module_def);')
+        prnt('  if (lib == NULL)')
+        prnt('    return NULL;')
+        prnt('  if (%s < 0 || _cffi_init() < 0) {' % (constants,))
+        prnt('    Py_DECREF(lib);')
+        prnt('    return NULL;')
+        prnt('  }')
+        prnt('  return lib;')
+        prnt('}')
+        prnt()
+        prnt('#else')
+        prnt()
+        prnt('PyMODINIT_FUNC')
+        prnt('init%s(void)' % modname)
+        prnt('{')
+        prnt('  PyObject *lib;')
+        prnt('  lib = Py_InitModule("%s", _cffi_methods);' % modname)
+        prnt('  if (lib == NULL)')
+        prnt('    return;')
+        prnt('  if (%s < 0 || _cffi_init() < 0)' % (constants,))
+        prnt('    return;')
+        prnt('  return;')
+        prnt('}')
+        prnt()
+        prnt('#endif')
+
+    def load_library(self, flags=None):
+        # XXX review all usages of 'self' here!
+        # import it as a new extension module
+        imp.acquire_lock()
+        try:
+            if hasattr(sys, "getdlopenflags"):
+                previous_flags = sys.getdlopenflags()
+            try:
+                if hasattr(sys, "setdlopenflags") and flags is not None:
+                    sys.setdlopenflags(flags)
+                module = imp.load_dynamic(self.verifier.get_module_name(),
+                                          self.verifier.modulefilename)
+            except ImportError as e:
+                error = "importing %r: %s" % (self.verifier.modulefilename, e)
+                raise VerificationError(error)
+            finally:
+                if hasattr(sys, "setdlopenflags"):
+                    sys.setdlopenflags(previous_flags)
+        finally:
+            imp.release_lock()
+        #
+        # call loading_cpy_struct() to get the struct layout inferred by
+        # the C compiler
+        self._load(module, 'loading')
+        #
+        # the C code will need the <ctype> objects.  Collect them in
+        # order in a list.
+        revmapping = dict([(value, key)
+                           for (key, value) in self._typesdict.items()])
+        lst = [revmapping[i] for i in range(len(revmapping))]
+        lst = list(map(self.ffi._get_cached_btype, lst))
+        #
+        # build the FFILibrary class and instance and call _cffi_setup().
+        # this will set up some fields like '_cffi_types', and only then
+        # it will invoke the chained list of functions that will really
+        # build (notably) the constant objects, as <cdata> if they are
+        # pointers, and store them as attributes on the 'library' object.
+        class FFILibrary(object):
+            _cffi_python_module = module
+            _cffi_ffi = self.ffi
+            _cffi_dir = []
+            def __dir__(self):
+                return FFILibrary._cffi_dir + list(self.__dict__)
+        library = FFILibrary()
+        if module._cffi_setup(lst, VerificationError, library):
+            import warnings
+            warnings.warn("reimporting %r might overwrite older definitions"
+                          % (self.verifier.get_module_name()))
+        #
+        # finally, call the loaded_cpy_xxx() functions.  This will perform
+        # the final adjustments, like copying the Python->C wrapper
+        # functions from the module to the 'library' object, and setting
+        # up the FFILibrary class with properties for the global C variables.
+        self._load(module, 'loaded', library=library)
+        module._cffi_original_ffi = self.ffi
+        module._cffi_types_of_builtin_funcs = self._types_of_builtin_functions
+        return library
+
+    def _get_declarations(self):
+        lst = [(key, tp) for (key, (tp, qual)) in
+                                self.ffi._parser._declarations.items()]
+        lst.sort()
+        return lst
+
+    def _generate(self, step_name):
+        for name, tp in self._get_declarations():
+            kind, realname = name.split(' ', 1)
+            try:
+                method = getattr(self, '_generate_cpy_%s_%s' % (kind,
+                                                                step_name))
+            except AttributeError:
+                raise VerificationError(
+                    "not implemented in verify(): %r" % name)
+            try:
+                method(tp, realname)
+            except Exception as e:
+                model.attach_exception_info(e, name)
+                raise
+
+    def _load(self, module, step_name, **kwds):
+        for name, tp in self._get_declarations():
+            kind, realname = name.split(' ', 1)
+            method = getattr(self, '_%s_cpy_%s' % (step_name, kind))
+            try:
+                method(tp, realname, module, **kwds)
+            except Exception as e:
+                model.attach_exception_info(e, name)
+                raise
+
+    def _generate_nothing(self, tp, name):
+        pass
+
+    def _loaded_noop(self, tp, name, module, **kwds):
+        pass
+
+    # ----------
+
+    def _convert_funcarg_to_c(self, tp, fromvar, tovar, errcode):
+        extraarg = ''
+        if isinstance(tp, model.PrimitiveType):
+            if tp.is_integer_type() and tp.name != '_Bool':
+                converter = '_cffi_to_c_int'
+                extraarg = ', %s' % tp.name
+            elif tp.is_complex_type():
+                raise VerificationError(
+                    "not implemented in verify(): complex types")
+            else:
+                converter = '(%s)_cffi_to_c_%s' % (tp.get_c_name(''),
+                                                   tp.name.replace(' ', '_'))
+            errvalue = '-1'
+        #
+        elif isinstance(tp, model.PointerType):
+            self._convert_funcarg_to_c_ptr_or_array(tp, fromvar,
+                                                    tovar, errcode)
+            return
+        #
+        elif isinstance(tp, (model.StructOrUnion, model.EnumType)):
+            # a struct (not a struct pointer) as a function argument
+            self._prnt('  if (_cffi_to_c((char *)&%s, _cffi_type(%d), %s) < 0)'
+                      % (tovar, self._gettypenum(tp), fromvar))
+            self._prnt('    %s;' % errcode)
+            return
+        #
+        elif isinstance(tp, model.FunctionPtrType):
+            converter = '(%s)_cffi_to_c_pointer' % tp.get_c_name('')
+            extraarg = ', _cffi_type(%d)' % self._gettypenum(tp)
+            errvalue = 'NULL'
+        #
+        else:
+            raise NotImplementedError(tp)
+        #
+        self._prnt('  %s = %s(%s%s);' % (tovar, converter, fromvar, extraarg))
+        self._prnt('  if (%s == (%s)%s && PyErr_Occurred())' % (
+            tovar, tp.get_c_name(''), errvalue))
+        self._prnt('    %s;' % errcode)
+
+    def _extra_local_variables(self, tp, localvars, freelines):
+        if isinstance(tp, model.PointerType):
+            localvars.add('Py_ssize_t datasize')
+            localvars.add('struct _cffi_freeme_s *large_args_free = NULL')
+            freelines.add('if (large_args_free != NULL)'
+                          ' _cffi_free_array_arguments(large_args_free);')
+
+    def _convert_funcarg_to_c_ptr_or_array(self, tp, fromvar, tovar, errcode):
+        self._prnt('  datasize = _cffi_prepare_pointer_call_argument(')
+        self._prnt('      _cffi_type(%d), %s, (char **)&%s);' % (
+            self._gettypenum(tp), fromvar, tovar))
+        self._prnt('  if (datasize != 0) {')
+        self._prnt('    %s = ((size_t)datasize) <= 640 ? '
+                   'alloca((size_t)datasize) : NULL;' % (tovar,))
+        self._prnt('    if (_cffi_convert_array_argument(_cffi_type(%d), %s, '
+                   '(char **)&%s,' % (self._gettypenum(tp), fromvar, tovar))
+        self._prnt('            datasize, &large_args_free) < 0)')
+        self._prnt('      %s;' % errcode)
+        self._prnt('  }')
+
+    def _convert_expr_from_c(self, tp, var, context):
+        if isinstance(tp, model.PrimitiveType):
+            if tp.is_integer_type() and tp.name != '_Bool':
+                return '_cffi_from_c_int(%s, %s)' % (var, tp.name)
+            elif tp.name != 'long double':
+                return '_cffi_from_c_%s(%s)' % (tp.name.replace(' ', '_'), var)
+            else:
+                return '_cffi_from_c_deref((char *)&%s, _cffi_type(%d))' % (
+                    var, self._gettypenum(tp))
+        elif isinstance(tp, (model.PointerType, model.FunctionPtrType)):
+            return '_cffi_from_c_pointer((char *)%s, _cffi_type(%d))' % (
+                var, self._gettypenum(tp))
+        elif isinstance(tp, model.ArrayType):
+            return '_cffi_from_c_pointer((char *)%s, _cffi_type(%d))' % (
+                var, self._gettypenum(model.PointerType(tp.item)))
+        elif isinstance(tp, model.StructOrUnion):
+            if tp.fldnames is None:
+                raise TypeError("'%s' is used as %s, but is opaque" % (
+                    tp._get_c_name(), context))
+            return '_cffi_from_c_struct((char *)&%s, _cffi_type(%d))' % (
+                var, self._gettypenum(tp))
+        elif isinstance(tp, model.EnumType):
+            return '_cffi_from_c_deref((char *)&%s, _cffi_type(%d))' % (
+                var, self._gettypenum(tp))
+        else:
+            raise NotImplementedError(tp)
+
+    # ----------
+    # typedefs: generates no code so far
+
+    _generate_cpy_typedef_collecttype = _generate_nothing
+    _generate_cpy_typedef_decl   = _generate_nothing
+    _generate_cpy_typedef_method = _generate_nothing
+    _loading_cpy_typedef         = _loaded_noop
+    _loaded_cpy_typedef          = _loaded_noop
+
+    # ----------
+    # function declarations
+
+    def _generate_cpy_function_collecttype(self, tp, name):
+        assert isinstance(tp, model.FunctionPtrType)
+        if tp.ellipsis:
+            self._do_collect_type(tp)
+        else:
+            # don't call _do_collect_type(tp) in this common case,
+            # otherwise test_autofilled_struct_as_argument fails
+            for type in tp.args:
+                self._do_collect_type(type)
+            self._do_collect_type(tp.result)
+
+    def _generate_cpy_function_decl(self, tp, name):
+        assert isinstance(tp, model.FunctionPtrType)
+        if tp.ellipsis:
+            # cannot support vararg functions better than this: check for its
+            # exact type (including the fixed arguments), and build it as a
+            # constant function pointer (no CPython wrapper)
+            self._generate_cpy_const(False, name, tp)
+            return
+        prnt = self._prnt
+        numargs = len(tp.args)
+        if numargs == 0:
+            argname = 'noarg'
+        elif numargs == 1:
+            argname = 'arg0'
+        else:
+            argname = 'args'
+        prnt('static PyObject *')
+        prnt('_cffi_f_%s(PyObject *self, PyObject *%s)' % (name, argname))
+        prnt('{')
+        #
+        context = 'argument of %s' % name
+        for i, type in enumerate(tp.args):
+            prnt('  %s;' % type.get_c_name(' x%d' % i, context))
+        #
+        localvars = set()
+        freelines = set()
+        for type in tp.args:
+            self._extra_local_variables(type, localvars, freelines)
+        for decl in sorted(localvars):
+            prnt('  %s;' % (decl,))
+        #
+        if not isinstance(tp.result, model.VoidType):
+            result_code = 'result = '
+            context = 'result of %s' % name
+            prnt('  %s;' % tp.result.get_c_name(' result', context))
+            prnt('  PyObject *pyresult;')
+        else:
+            result_code = ''
+        #
+        if len(tp.args) > 1:
+            rng = range(len(tp.args))
+            for i in rng:
+                prnt('  PyObject *arg%d;' % i)
+            prnt()
+            prnt('  if (!PyArg_ParseTuple(args, "%s:%s", %s))' % (
+                'O' * numargs, name, ', '.join(['&arg%d' % i for i in rng])))
+            prnt('    return NULL;')
+        prnt()
+        #
+        for i, type in enumerate(tp.args):
+            self._convert_funcarg_to_c(type, 'arg%d' % i, 'x%d' % i,
+                                       'return NULL')
+            prnt()
+        #
+        prnt('  Py_BEGIN_ALLOW_THREADS')
+        prnt('  _cffi_restore_errno();')
+        prnt('  { %s%s(%s); }' % (
+            result_code, name,
+            ', '.join(['x%d' % i for i in range(len(tp.args))])))
+        prnt('  _cffi_save_errno();')
+        prnt('  Py_END_ALLOW_THREADS')
+        prnt()
+        #
+        prnt('  (void)self; /* unused */')
+        if numargs == 0:
+            prnt('  (void)noarg; /* unused */')
+        if result_code:
+            prnt('  pyresult = %s;' %
+                 self._convert_expr_from_c(tp.result, 'result', 'result type'))
+            for freeline in freelines:
+                prnt('  ' + freeline)
+            prnt('  return pyresult;')
+        else:
+            for freeline in freelines:
+                prnt('  ' + freeline)
+            prnt('  Py_INCREF(Py_None);')
+            prnt('  return Py_None;')
+        prnt('}')
+        prnt()
+
+    def _generate_cpy_function_method(self, tp, name):
+        if tp.ellipsis:
+            return
+        numargs = len(tp.args)
+        if numargs == 0:
+            meth = 'METH_NOARGS'
+        elif numargs == 1:
+            meth = 'METH_O'
+        else:
+            meth = 'METH_VARARGS'
+        self._prnt('  {"%s", _cffi_f_%s, %s, NULL},' % (name, name, meth))
+
+    _loading_cpy_function = _loaded_noop
+
+    def _loaded_cpy_function(self, tp, name, module, library):
+        if tp.ellipsis:
+            return
+        func = getattr(module, name)
+        setattr(library, name, func)
+        self._types_of_builtin_functions[func] = tp
+
+    # ----------
+    # named structs
+
+    _generate_cpy_struct_collecttype = _generate_nothing
+    def _generate_cpy_struct_decl(self, tp, name):
+        assert name == tp.name
+        self._generate_struct_or_union_decl(tp, 'struct', name)
+    def _generate_cpy_struct_method(self, tp, name):
+        self._generate_struct_or_union_method(tp, 'struct', name)
+    def _loading_cpy_struct(self, tp, name, module):
+        self._loading_struct_or_union(tp, 'struct', name, module)
+    def _loaded_cpy_struct(self, tp, name, module, **kwds):
+        self._loaded_struct_or_union(tp)
+
+    _generate_cpy_union_collecttype = _generate_nothing
+    def _generate_cpy_union_decl(self, tp, name):
+        assert name == tp.name
+        self._generate_struct_or_union_decl(tp, 'union', name)
+    def _generate_cpy_union_method(self, tp, name):
+        self._generate_struct_or_union_method(tp, 'union', name)
+    def _loading_cpy_union(self, tp, name, module):
+        self._loading_struct_or_union(tp, 'union', name, module)
+    def _loaded_cpy_union(self, tp, name, module, **kwds):
+        self._loaded_struct_or_union(tp)
+
+    def _generate_struct_or_union_decl(self, tp, prefix, name):
+        if tp.fldnames is None:
+            return     # nothing to do with opaque structs
+        checkfuncname = '_cffi_check_%s_%s' % (prefix, name)
+        layoutfuncname = '_cffi_layout_%s_%s' % (prefix, name)
+        cname = ('%s %s' % (prefix, name)).strip()
+        #
+        prnt = self._prnt
+        prnt('static void %s(%s *p)' % (checkfuncname, cname))
+        prnt('{')
+        prnt('  /* only to generate compile-time warnings or errors */')
+        prnt('  (void)p;')
+        for fname, ftype, fbitsize, fqual in tp.enumfields():
+            if (isinstance(ftype, model.PrimitiveType)
+                and ftype.is_integer_type()) or fbitsize >= 0:
+                # accept all integers, but complain on float or double
+                prnt('  (void)((p->%s) << 1);' % fname)
+            else:
+                # only accept exactly the type declared.
+                try:
+                    prnt('  { %s = &p->%s; (void)tmp; }' % (
+                        ftype.get_c_name('*tmp', 'field %r'%fname, quals=fqual),
+                        fname))
+                except VerificationError as e:
+                    prnt('  /* %s */' % str(e))   # cannot verify it, ignore
+        prnt('}')
+        prnt('static PyObject *')
+        prnt('%s(PyObject *self, PyObject *noarg)' % (layoutfuncname,))
+        prnt('{')
+        prnt('  struct _cffi_aligncheck { char x; %s y; };' % cname)
+        prnt('  static Py_ssize_t nums[] = {')
+        prnt('    sizeof(%s),' % cname)
+        prnt('    offsetof(struct _cffi_aligncheck, y),')
+        for fname, ftype, fbitsize, fqual in tp.enumfields():
+            if fbitsize >= 0:
+                continue      # xxx ignore fbitsize for now
+            prnt('    offsetof(%s, %s),' % (cname, fname))
+            if isinstance(ftype, model.ArrayType) and ftype.length is None:
+                prnt('    0,  /* %s */' % ftype._get_c_name())
+            else:
+                prnt('    sizeof(((%s *)0)->%s),' % (cname, fname))
+        prnt('    -1')
+        prnt('  };')
+        prnt('  (void)self; /* unused */')
+        prnt('  (void)noarg; /* unused */')
+        prnt('  return _cffi_get_struct_layout(nums);')
+        prnt('  /* the next line is not executed, but compiled */')
+        prnt('  %s(0);' % (checkfuncname,))
+        prnt('}')
+        prnt()
+
+    def _generate_struct_or_union_method(self, tp, prefix, name):
+        if tp.fldnames is None:
+            return     # nothing to do with opaque structs
+        layoutfuncname = '_cffi_layout_%s_%s' % (prefix, name)
+        self._prnt('  {"%s", %s, METH_NOARGS, NULL},' % (layoutfuncname,
+                                                         layoutfuncname))
+
+    def _loading_struct_or_union(self, tp, prefix, name, module):
+        if tp.fldnames is None:
+            return     # nothing to do with opaque structs
+        layoutfuncname = '_cffi_layout_%s_%s' % (prefix, name)
+        #
+        function = getattr(module, layoutfuncname)
+        layout = function()
+        if isinstance(tp, model.StructOrUnion) and tp.partial:
+            # use the function()'s sizes and offsets to guide the
+            # layout of the struct
+            totalsize = layout[0]
+            totalalignment = layout[1]
+            fieldofs = layout[2::2]
+            fieldsize = layout[3::2]
+            tp.force_flatten()
+            assert len(fieldofs) == len(fieldsize) == len(tp.fldnames)
+            tp.fixedlayout = fieldofs, fieldsize, totalsize, totalalignment
+        else:
+            cname = ('%s %s' % (prefix, name)).strip()
+            self._struct_pending_verification[tp] = layout, cname
+
+    def _loaded_struct_or_union(self, tp):
+        if tp.fldnames is None:
+            return     # nothing to do with opaque structs
+        self.ffi._get_cached_btype(tp)   # force 'fixedlayout' to be considered
+
+        if tp in self._struct_pending_verification:
+            # check that the layout sizes and offsets match the real ones
+            def check(realvalue, expectedvalue, msg):
+                if realvalue != expectedvalue:
+                    raise VerificationError(
+                        "%s (we have %d, but C compiler says %d)"
+                        % (msg, expectedvalue, realvalue))
+            ffi = self.ffi
+            BStruct = ffi._get_cached_btype(tp)
+            layout, cname = self._struct_pending_verification.pop(tp)
+            check(layout[0], ffi.sizeof(BStruct), "wrong total size")
+            check(layout[1], ffi.alignof(BStruct), "wrong total alignment")
+            i = 2
+            for fname, ftype, fbitsize, fqual in tp.enumfields():
+                if fbitsize >= 0:
+                    continue        # xxx ignore fbitsize for now
+                check(layout[i], ffi.offsetof(BStruct, fname),
+                      "wrong offset for field %r" % (fname,))
+                if layout[i+1] != 0:
+                    BField = ffi._get_cached_btype(ftype)
+                    check(layout[i+1], ffi.sizeof(BField),
+                          "wrong size for field %r" % (fname,))
+                i += 2
+            assert i == len(layout)
+
+    # ----------
+    # 'anonymous' declarations.  These are produced for anonymous structs
+    # or unions; the 'name' is obtained by a typedef.
+
+    _generate_cpy_anonymous_collecttype = _generate_nothing
+
+    def _generate_cpy_anonymous_decl(self, tp, name):
+        if isinstance(tp, model.EnumType):
+            self._generate_cpy_enum_decl(tp, name, '')
+        else:
+            self._generate_struct_or_union_decl(tp, '', name)
+
+    def _generate_cpy_anonymous_method(self, tp, name):
+        if not isinstance(tp, model.EnumType):
+            self._generate_struct_or_union_method(tp, '', name)
+
+    def _loading_cpy_anonymous(self, tp, name, module):
+        if isinstance(tp, model.EnumType):
+            self._loading_cpy_enum(tp, name, module)
+        else:
+            self._loading_struct_or_union(tp, '', name, module)
+
+    def _loaded_cpy_anonymous(self, tp, name, module, **kwds):
+        if isinstance(tp, model.EnumType):
+            self._loaded_cpy_enum(tp, name, module, **kwds)
+        else:
+            self._loaded_struct_or_union(tp)
+
+    # ----------
+    # constants, likely declared with '#define'
+
+    def _generate_cpy_const(self, is_int, name, tp=None, category='const',
+                            vartp=None, delayed=True, size_too=False,
+                            check_value=None):
+        prnt = self._prnt
+        funcname = '_cffi_%s_%s' % (category, name)
+        prnt('static int %s(PyObject *lib)' % funcname)
+        prnt('{')
+        prnt('  PyObject *o;')
+        prnt('  int res;')
+        if not is_int:
+            prnt('  %s;' % (vartp or tp).get_c_name(' i', name))
+        else:
+            assert category == 'const'
+        #
+        if check_value is not None:
+            self._check_int_constant_value(name, check_value)
+        #
+        if not is_int:
+            if category == 'var':
+                realexpr = '&' + name
+            else:
+                realexpr = name
+            prnt('  i = (%s);' % (realexpr,))
+            prnt('  o = %s;' % (self._convert_expr_from_c(tp, 'i',
+                                                          'variable type'),))
+            assert delayed
+        else:
+            prnt('  o = _cffi_from_c_int_const(%s);' % name)
+        prnt('  if (o == NULL)')
+        prnt('    return -1;')
+        if size_too:
+            prnt('  {')
+            prnt('    PyObject *o1 = o;')
+            prnt('    o = Py_BuildValue("On", o1, (Py_ssize_t)sizeof(%s));'
+                 % (name,))
+            prnt('    Py_DECREF(o1);')
+            prnt('    if (o == NULL)')
+            prnt('      return -1;')
+            prnt('  }')
+        prnt('  res = PyObject_SetAttrString(lib, "%s", o);' % name)
+        prnt('  Py_DECREF(o);')
+        prnt('  if (res < 0)')
+        prnt('    return -1;')
+        prnt('  return %s;' % self._chained_list_constants[delayed])
+        self._chained_list_constants[delayed] = funcname + '(lib)'
+        prnt('}')
+        prnt()
+
+    def _generate_cpy_constant_collecttype(self, tp, name):
+        is_int = isinstance(tp, model.PrimitiveType) and tp.is_integer_type()
+        if not is_int:
+            self._do_collect_type(tp)
+
+    def _generate_cpy_constant_decl(self, tp, name):
+        is_int = isinstance(tp, model.PrimitiveType) and tp.is_integer_type()
+        self._generate_cpy_const(is_int, name, tp)
+
+    _generate_cpy_constant_method = _generate_nothing
+    _loading_cpy_constant = _loaded_noop
+    _loaded_cpy_constant  = _loaded_noop
+
+    # ----------
+    # enums
+
+    def _check_int_constant_value(self, name, value, err_prefix=''):
+        prnt = self._prnt
+        if value <= 0:
+            prnt('  if ((%s) > 0 || (long)(%s) != %dL) {' % (
+                name, name, value))
+        else:
+            prnt('  if ((%s) <= 0 || (unsigned long)(%s) != %dUL) {' % (
+                name, name, value))
+        prnt('    char buf[64];')
+        prnt('    if ((%s) <= 0)' % name)
+        prnt('        snprintf(buf, 63, "%%ld", (long)(%s));' % name)
+        prnt('    else')
+        prnt('        snprintf(buf, 63, "%%lu", (unsigned long)(%s));' %
+             name)
+        prnt('    PyErr_Format(_cffi_VerificationError,')
+        prnt('                 "%s%s has the real value %s, not %s",')
+        prnt('                 "%s", "%s", buf, "%d");' % (
+            err_prefix, name, value))
+        prnt('    return -1;')
+        prnt('  }')
+
+    def _enum_funcname(self, prefix, name):
+        # "$enum_$1" => "___D_enum____D_1"
+        name = name.replace('$', '___D_')
+        return '_cffi_e_%s_%s' % (prefix, name)
+
+    def _generate_cpy_enum_decl(self, tp, name, prefix='enum'):
+        if tp.partial:
+            for enumerator in tp.enumerators:
+                self._generate_cpy_const(True, enumerator, delayed=False)
+            return
+        #
+        funcname = self._enum_funcname(prefix, name)
+        prnt = self._prnt
+        prnt('static int %s(PyObject *lib)' % funcname)
+        prnt('{')
+        for enumerator, enumvalue in zip(tp.enumerators, tp.enumvalues):
+            self._check_int_constant_value(enumerator, enumvalue,
+                                           "enum %s: " % name)
+        prnt('  return %s;' % self._chained_list_constants[True])
+        self._chained_list_constants[True] = funcname + '(lib)'
+        prnt('}')
+        prnt()
+
+    _generate_cpy_enum_collecttype = _generate_nothing
+    _generate_cpy_enum_method = _generate_nothing
+
+    def _loading_cpy_enum(self, tp, name, module):
+        if tp.partial:
+            enumvalues = [getattr(module, enumerator)
+                          for enumerator in tp.enumerators]
+            tp.enumvalues = tuple(enumvalues)
+            tp.partial_resolved = True
+
+    def _loaded_cpy_enum(self, tp, name, module, library):
+        for enumerator, enumvalue in zip(tp.enumerators, tp.enumvalues):
+            setattr(library, enumerator, enumvalue)
+
+    # ----------
+    # macros: for now only for integers
+
+    def _generate_cpy_macro_decl(self, tp, name):
+        if tp == '...':
+            check_value = None
+        else:
+            check_value = tp     # an integer
+        self._generate_cpy_const(True, name, check_value=check_value)
+
+    _generate_cpy_macro_collecttype = _generate_nothing
+    _generate_cpy_macro_method = _generate_nothing
+    _loading_cpy_macro = _loaded_noop
+    _loaded_cpy_macro  = _loaded_noop
+
+    # ----------
+    # global variables
+
+    def _generate_cpy_variable_collecttype(self, tp, name):
+        if isinstance(tp, model.ArrayType):
+            tp_ptr = model.PointerType(tp.item)
+        else:
+            tp_ptr = model.PointerType(tp)
+        self._do_collect_type(tp_ptr)
+
+    def _generate_cpy_variable_decl(self, tp, name):
+        if isinstance(tp, model.ArrayType):
+            tp_ptr = model.PointerType(tp.item)
+            self._generate_cpy_const(False, name, tp, vartp=tp_ptr,
+                                     size_too = tp.length_is_unknown())
+        else:
+            tp_ptr = model.PointerType(tp)
+            self._generate_cpy_const(False, name, tp_ptr, category='var')
+
+    _generate_cpy_variable_method = _generate_nothing
+    _loading_cpy_variable = _loaded_noop
+
+    def _loaded_cpy_variable(self, tp, name, module, library):
+        value = getattr(library, name)
+        if isinstance(tp, model.ArrayType):   # int a[5] is "constant" in the
+                                              # sense that "a=..." is forbidden
+            if tp.length_is_unknown():
+                assert isinstance(value, tuple)
+                (value, size) = value
+                BItemType = self.ffi._get_cached_btype(tp.item)
+                length, rest = divmod(size, self.ffi.sizeof(BItemType))
+                if rest != 0:
+                    raise VerificationError(
+                        "bad size: %r does not seem to be an array of %s" %
+                        (name, tp.item))
+                tp = tp.resolve_length(length)
+            # 'value' is a <cdata 'type *'> which we have to replace with
+            # a <cdata 'type[N]'> if the N is actually known
+            if tp.length is not None:
+                BArray = self.ffi._get_cached_btype(tp)
+                value = self.ffi.cast(BArray, value)
+                setattr(library, name, value)
+            return
+        # remove ptr=<cdata 'int *'> from the library instance, and replace
+        # it by a property on the class, which reads/writes into ptr[0].
+        ptr = value
+        delattr(library, name)
+        def getter(library):
+            return ptr[0]
+        def setter(library, value):
+            ptr[0] = value
+        setattr(type(library), name, property(getter, setter))
+        type(library)._cffi_dir.append(name)
+
+    # ----------
+
+    def _generate_setup_custom(self):
+        prnt = self._prnt
+        prnt('static int _cffi_setup_custom(PyObject *lib)')
+        prnt('{')
+        prnt('  return %s;' % self._chained_list_constants[True])
+        prnt('}')
+
+cffimod_header = r'''
+#include <Python.h>
+#include <stddef.h>
+
+/* this block of #ifs should be kept exactly identical between
+   c/_cffi_backend.c, cffi/vengine_cpy.py, cffi/vengine_gen.py
+   and cffi/_cffi_include.h */
+#if defined(_MSC_VER)
+# include <malloc.h>   /* for alloca() */
+# if _MSC_VER < 1600   /* MSVC < 2010 */
+   typedef __int8 int8_t;
+   typedef __int16 int16_t;
+   typedef __int32 int32_t;
+   typedef __int64 int64_t;
+   typedef unsigned __int8 uint8_t;
+   typedef unsigned __int16 uint16_t;
+   typedef unsigned __int32 uint32_t;
+   typedef unsigned __int64 uint64_t;
+   typedef __int8 int_least8_t;
+   typedef __int16 int_least16_t;
+   typedef __int32 int_least32_t;
+   typedef __int64 int_least64_t;
+   typedef unsigned __int8 uint_least8_t;
+   typedef unsigned __int16 uint_least16_t;
+   typedef unsigned __int32 uint_least32_t;
+   typedef unsigned __int64 uint_least64_t;
+   typedef __int8 int_fast8_t;
+   typedef __int16 int_fast16_t;
+   typedef __int32 int_fast32_t;
+   typedef __int64 int_fast64_t;
+   typedef unsigned __int8 uint_fast8_t;
+   typedef unsigned __int16 uint_fast16_t;
+   typedef unsigned __int32 uint_fast32_t;
+   typedef unsigned __int64 uint_fast64_t;
+   typedef __int64 intmax_t;
+   typedef unsigned __int64 uintmax_t;
+# else
+#  include <stdint.h>
+# endif
+# if _MSC_VER < 1800   /* MSVC < 2013 */
+#  ifndef __cplusplus
+    typedef unsigned char _Bool;
+#  endif
+# endif
+# define _cffi_float_complex_t   _Fcomplex    /* include <complex.h> for it */
+# define _cffi_double_complex_t  _Dcomplex    /* include <complex.h> for it */
+#else
+# include <stdint.h>
+# if (defined (__SVR4) && defined (__sun)) || defined(_AIX) || defined(__hpux)
+#  include <alloca.h>
+# endif
+# define _cffi_float_complex_t   float _Complex
+# define _cffi_double_complex_t  double _Complex
+#endif
+
+#if PY_MAJOR_VERSION < 3
+# undef PyCapsule_CheckExact
+# undef PyCapsule_GetPointer
+# define PyCapsule_CheckExact(capsule) (PyCObject_Check(capsule))
+# define PyCapsule_GetPointer(capsule, name) \
+    (PyCObject_AsVoidPtr(capsule))
+#endif
+
+#if PY_MAJOR_VERSION >= 3
+# define PyInt_FromLong PyLong_FromLong
+#endif
+
+#define _cffi_from_c_double PyFloat_FromDouble
+#define _cffi_from_c_float PyFloat_FromDouble
+#define _cffi_from_c_long PyInt_FromLong
+#define _cffi_from_c_ulong PyLong_FromUnsignedLong
+#define _cffi_from_c_longlong PyLong_FromLongLong
+#define _cffi_from_c_ulonglong PyLong_FromUnsignedLongLong
+#define _cffi_from_c__Bool PyBool_FromLong
+
+#define _cffi_to_c_double PyFloat_AsDouble
+#define _cffi_to_c_float PyFloat_AsDouble
+
+#define _cffi_from_c_int_const(x)                                        \
+    (((x) > 0) ?                                                         \
+        ((unsigned long long)(x) <= (unsigned long long)LONG_MAX) ?      \
+            PyInt_FromLong((long)(x)) :                                  \
+            PyLong_FromUnsignedLongLong((unsigned long long)(x)) :       \
+        ((long long)(x) >= (long long)LONG_MIN) ?                        \
+            PyInt_FromLong((long)(x)) :                                  \
+            PyLong_FromLongLong((long long)(x)))
+
+#define _cffi_from_c_int(x, type)                                        \
+    (((type)-1) > 0 ? /* unsigned */                                     \
+        (sizeof(type) < sizeof(long) ?                                   \
+            PyInt_FromLong((long)x) :                                    \
+         sizeof(type) == sizeof(long) ?                                  \
+            PyLong_FromUnsignedLong((unsigned long)x) :                  \
+            PyLong_FromUnsignedLongLong((unsigned long long)x)) :        \
+        (sizeof(type) <= sizeof(long) ?                                  \
+            PyInt_FromLong((long)x) :                                    \
+            PyLong_FromLongLong((long long)x)))
+
+#define _cffi_to_c_int(o, type)                                          \
+    ((type)(                                                             \
+     sizeof(type) == 1 ? (((type)-1) > 0 ? (type)_cffi_to_c_u8(o)        \
+                                         : (type)_cffi_to_c_i8(o)) :     \
+     sizeof(type) == 2 ? (((type)-1) > 0 ? (type)_cffi_to_c_u16(o)       \
+                                         : (type)_cffi_to_c_i16(o)) :    \
+     sizeof(type) == 4 ? (((type)-1) > 0 ? (type)_cffi_to_c_u32(o)       \
+                                         : (type)_cffi_to_c_i32(o)) :    \
+     sizeof(type) == 8 ? (((type)-1) > 0 ? (type)_cffi_to_c_u64(o)       \
+                                         : (type)_cffi_to_c_i64(o)) :    \
+     (Py_FatalError("unsupported size for type " #type), (type)0)))
+
+#define _cffi_to_c_i8                                                    \
+                 ((int(*)(PyObject *))_cffi_exports[1])
+#define _cffi_to_c_u8                                                    \
+                 ((int(*)(PyObject *))_cffi_exports[2])
+#define _cffi_to_c_i16                                                   \
+                 ((int(*)(PyObject *))_cffi_exports[3])
+#define _cffi_to_c_u16                                                   \
+                 ((int(*)(PyObject *))_cffi_exports[4])
+#define _cffi_to_c_i32                                                   \
+                 ((int(*)(PyObject *))_cffi_exports[5])
+#define _cffi_to_c_u32                                                   \
+                 ((unsigned int(*)(PyObject *))_cffi_exports[6])
+#define _cffi_to_c_i64                                                   \
+                 ((long long(*)(PyObject *))_cffi_exports[7])
+#define _cffi_to_c_u64                                                   \
+                 ((unsigned long long(*)(PyObject *))_cffi_exports[8])
+#define _cffi_to_c_char                                                  \
+                 ((int(*)(PyObject *))_cffi_exports[9])
+#define _cffi_from_c_pointer                                             \
+    ((PyObject *(*)(char *, CTypeDescrObject *))_cffi_exports[10])
+#define _cffi_to_c_pointer                                               \
+    ((char *(*)(PyObject *, CTypeDescrObject *))_cffi_exports[11])
+#define _cffi_get_struct_layout                                          \
+    ((PyObject *(*)(Py_ssize_t[]))_cffi_exports[12])
+#define _cffi_restore_errno                                              \
+    ((void(*)(void))_cffi_exports[13])
+#define _cffi_save_errno                                                 \
+    ((void(*)(void))_cffi_exports[14])
+#define _cffi_from_c_char                                                \
+    ((PyObject *(*)(char))_cffi_exports[15])
+#define _cffi_from_c_deref                                               \
+    ((PyObject *(*)(char *, CTypeDescrObject *))_cffi_exports[16])
+#define _cffi_to_c                                                       \
+    ((int(*)(char *, CTypeDescrObject *, PyObject *))_cffi_exports[17])
+#define _cffi_from_c_struct                                              \
+    ((PyObject *(*)(char *, CTypeDescrObject *))_cffi_exports[18])
+#define _cffi_to_c_wchar_t                                               \
+    ((wchar_t(*)(PyObject *))_cffi_exports[19])
+#define _cffi_from_c_wchar_t                                             \
+    ((PyObject *(*)(wchar_t))_cffi_exports[20])
+#define _cffi_to_c_long_double                                           \
+    ((long double(*)(PyObject *))_cffi_exports[21])
+#define _cffi_to_c__Bool                                                 \
+    ((_Bool(*)(PyObject *))_cffi_exports[22])
+#define _cffi_prepare_pointer_call_argument                              \
+    ((Py_ssize_t(*)(CTypeDescrObject *, PyObject *, char **))_cffi_exports[23])
+#define _cffi_convert_array_from_object                                  \
+    ((int(*)(char *, CTypeDescrObject *, PyObject *))_cffi_exports[24])
+#define _CFFI_NUM_EXPORTS 25
+
+typedef struct _ctypedescr CTypeDescrObject;
+
+static void *_cffi_exports[_CFFI_NUM_EXPORTS];
+static PyObject *_cffi_types, *_cffi_VerificationError;
+
+static int _cffi_setup_custom(PyObject *lib);   /* forward */
+
+static PyObject *_cffi_setup(PyObject *self, PyObject *args)
+{
+    PyObject *library;
+    int was_alive = (_cffi_types != NULL);
+    (void)self; /* unused */
+    if (!PyArg_ParseTuple(args, "OOO", &_cffi_types, &_cffi_VerificationError,
+                                       &library))
+        return NULL;
+    Py_INCREF(_cffi_types);
+    Py_INCREF(_cffi_VerificationError);
+    if (_cffi_setup_custom(library) < 0)
+        return NULL;
+    return PyBool_FromLong(was_alive);
+}
+
+union _cffi_union_alignment_u {
+    unsigned char m_char;
+    unsigned short m_short;
+    unsigned int m_int;
+    unsigned long m_long;
+    unsigned long long m_longlong;
+    float m_float;
+    double m_double;
+    long double m_longdouble;
+};
+
+struct _cffi_freeme_s {
+    struct _cffi_freeme_s *next;
+    union _cffi_union_alignment_u alignment;
+};
+
+#ifdef __GNUC__
+  __attribute__((unused))
+#endif
+static int _cffi_convert_array_argument(CTypeDescrObject *ctptr, PyObject *arg,
+                                        char **output_data, Py_ssize_t datasize,
+                                        struct _cffi_freeme_s **freeme)
+{
+    char *p;
+    if (datasize < 0)
+        return -1;
+
+    p = *output_data;
+    if (p == NULL) {
+        struct _cffi_freeme_s *fp = (struct _cffi_freeme_s *)PyObject_Malloc(
+            offsetof(struct _cffi_freeme_s, alignment) + (size_t)datasize);
+        if (fp == NULL)
+            return -1;
+        fp->next = *freeme;
+        *freeme = fp;
+        p = *output_data = (char *)&fp->alignment;
+    }
+    memset((void *)p, 0, (size_t)datasize);
+    return _cffi_convert_array_from_object(p, ctptr, arg);
+}
+
+#ifdef __GNUC__
+  __attribute__((unused))
+#endif
+static void _cffi_free_array_arguments(struct _cffi_freeme_s *freeme)
+{
+    do {
+        void *p = (void *)freeme;
+        freeme = freeme->next;
+        PyObject_Free(p);
+    } while (freeme != NULL);
+}
+
+static int _cffi_init(void)
+{
+    PyObject *module, *c_api_object = NULL;
+
+    module = PyImport_ImportModule("_cffi_backend");
+    if (module == NULL)
+        goto failure;
+
+    c_api_object = PyObject_GetAttrString(module, "_C_API");
+    if (c_api_object == NULL)
+        goto failure;
+    if (!PyCapsule_CheckExact(c_api_object)) {
+        PyErr_SetNone(PyExc_ImportError);
+        goto failure;
+    }
+    memcpy(_cffi_exports, PyCapsule_GetPointer(c_api_object, "cffi"),
+           _CFFI_NUM_EXPORTS * sizeof(void *));
+
+    Py_DECREF(module);
+    Py_DECREF(c_api_object);
+    return 0;
+
+  failure:
+    Py_XDECREF(module);
+    Py_XDECREF(c_api_object);
+    return -1;
+}
+
+#define _cffi_type(num) ((CTypeDescrObject *)PyList_GET_ITEM(_cffi_types, num))
+
+/**********/
+'''