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#
# DEPRECATED: implementation for ffi.verify()
#
import sys, os
import types
from . import model
from .error import VerificationError
class VGenericEngine(object):
_class_key = 'g'
_gen_python_module = False
def __init__(self, verifier):
self.verifier = verifier
self.ffi = verifier.ffi
self.export_symbols = []
self._struct_pending_verification = {}
def patch_extension_kwds(self, kwds):
# add 'export_symbols' to the dictionary. Note that we add the
# list before filling it. When we fill it, it will thus also show
# up in kwds['export_symbols'].
kwds.setdefault('export_symbols', self.export_symbols)
def find_module(self, module_name, path, so_suffixes):
for so_suffix in so_suffixes:
basename = module_name + so_suffix
if path is None:
path = sys.path
for dirname in path:
filename = os.path.join(dirname, basename)
if os.path.isfile(filename):
return filename
def collect_types(self):
pass # not needed in the generic engine
def _prnt(self, what=''):
self._f.write(what + '\n')
def write_source_to_f(self):
prnt = self._prnt
# first paste some standard set of lines that are mostly '#include'
prnt(cffimod_header)
# then paste the C source given by the user, verbatim.
prnt(self.verifier.preamble)
#
# call generate_gen_xxx_decl(), for every xxx found from
# ffi._parser._declarations. This generates all the functions.
self._generate('decl')
#
# on Windows, distutils insists on putting init_cffi_xyz in
# 'export_symbols', so instead of fighting it, just give up and
# give it one
if sys.platform == 'win32':
if sys.version_info >= (3,):
prefix = 'PyInit_'
else:
prefix = 'init'
modname = self.verifier.get_module_name()
prnt("void %s%s(void) { }\n" % (prefix, modname))
def load_library(self, flags=0):
# import it with the CFFI backend
backend = self.ffi._backend
# needs to make a path that contains '/', on Posix
filename = os.path.join(os.curdir, self.verifier.modulefilename)
module = backend.load_library(filename, flags)
#
# call loading_gen_struct() to get the struct layout inferred by
# the C compiler
self._load(module, 'loading')
# build the FFILibrary class and instance, this is a module subclass
# because modules are expected to have usually-constant-attributes and
# in PyPy this means the JIT is able to treat attributes as constant,
# which we want.
class FFILibrary(types.ModuleType):
_cffi_generic_module = module
_cffi_ffi = self.ffi
_cffi_dir = []
def __dir__(self):
return FFILibrary._cffi_dir
library = FFILibrary("")
#
# finally, call the loaded_gen_xxx() functions. This will set
# up the 'library' object.
self._load(module, 'loaded', library=library)
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_gen_%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_gen_%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
# ----------
# typedefs: generates no code so far
_generate_gen_typedef_decl = _generate_nothing
_loading_gen_typedef = _loaded_noop
_loaded_gen_typedef = _loaded_noop
# ----------
# function declarations
def _generate_gen_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 _cffi_f_%s wrapper)
self._generate_gen_const(False, name, tp)
return
prnt = self._prnt
numargs = len(tp.args)
argnames = []
for i, type in enumerate(tp.args):
indirection = ''
if isinstance(type, model.StructOrUnion):
indirection = '*'
argnames.append('%sx%d' % (indirection, i))
context = 'argument of %s' % name
arglist = [type.get_c_name(' %s' % arg, context)
for type, arg in zip(tp.args, argnames)]
tpresult = tp.result
if isinstance(tpresult, model.StructOrUnion):
arglist.insert(0, tpresult.get_c_name(' *r', context))
tpresult = model.void_type
arglist = ', '.join(arglist) or 'void'
wrappername = '_cffi_f_%s' % name
self.export_symbols.append(wrappername)
if tp.abi:
abi = tp.abi + ' '
else:
abi = ''
funcdecl = ' %s%s(%s)' % (abi, wrappername, arglist)
context = 'result of %s' % name
prnt(tpresult.get_c_name(funcdecl, context))
prnt('{')
#
if isinstance(tp.result, model.StructOrUnion):
result_code = '*r = '
elif not isinstance(tp.result, model.VoidType):
result_code = 'return '
else:
result_code = ''
prnt(' %s%s(%s);' % (result_code, name, ', '.join(argnames)))
prnt('}')
prnt()
_loading_gen_function = _loaded_noop
def _loaded_gen_function(self, tp, name, module, library):
assert isinstance(tp, model.FunctionPtrType)
if tp.ellipsis:
newfunction = self._load_constant(False, tp, name, module)
else:
indirections = []
base_tp = tp
if (any(isinstance(typ, model.StructOrUnion) for typ in tp.args)
or isinstance(tp.result, model.StructOrUnion)):
indirect_args = []
for i, typ in enumerate(tp.args):
if isinstance(typ, model.StructOrUnion):
typ = model.PointerType(typ)
indirections.append((i, typ))
indirect_args.append(typ)
indirect_result = tp.result
if isinstance(indirect_result, model.StructOrUnion):
if indirect_result.fldtypes is None:
raise TypeError("'%s' is used as result type, "
"but is opaque" % (
indirect_result._get_c_name(),))
indirect_result = model.PointerType(indirect_result)
indirect_args.insert(0, indirect_result)
indirections.insert(0, ("result", indirect_result))
indirect_result = model.void_type
tp = model.FunctionPtrType(tuple(indirect_args),
indirect_result, tp.ellipsis)
BFunc = self.ffi._get_cached_btype(tp)
wrappername = '_cffi_f_%s' % name
newfunction = module.load_function(BFunc, wrappername)
for i, typ in indirections:
newfunction = self._make_struct_wrapper(newfunction, i, typ,
base_tp)
setattr(library, name, newfunction)
type(library)._cffi_dir.append(name)
def _make_struct_wrapper(self, oldfunc, i, tp, base_tp):
backend = self.ffi._backend
BType = self.ffi._get_cached_btype(tp)
if i == "result":
ffi = self.ffi
def newfunc(*args):
res = ffi.new(BType)
oldfunc(res, *args)
return res[0]
else:
def newfunc(*args):
args = args[:i] + (backend.newp(BType, args[i]),) + args[i+1:]
return oldfunc(*args)
newfunc._cffi_base_type = base_tp
return newfunc
# ----------
# named structs
def _generate_gen_struct_decl(self, tp, name):
assert name == tp.name
self._generate_struct_or_union_decl(tp, 'struct', name)
def _loading_gen_struct(self, tp, name, module):
self._loading_struct_or_union(tp, 'struct', name, module)
def _loaded_gen_struct(self, tp, name, module, **kwds):
self._loaded_struct_or_union(tp)
def _generate_gen_union_decl(self, tp, name):
assert name == tp.name
self._generate_struct_or_union_decl(tp, 'union', name)
def _loading_gen_union(self, tp, name, module):
self._loading_struct_or_union(tp, 'union', name, module)
def _loaded_gen_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('}')
self.export_symbols.append(layoutfuncname)
prnt('intptr_t %s(intptr_t i)' % (layoutfuncname,))
prnt('{')
prnt(' struct _cffi_aligncheck { char x; %s y; };' % cname)
prnt(' static intptr_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(' return nums[i];')
prnt(' /* the next line is not executed, but compiled */')
prnt(' %s(0);' % (checkfuncname,))
prnt('}')
prnt()
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)
#
BFunc = self.ffi._typeof_locked("intptr_t(*)(intptr_t)")[0]
function = module.load_function(BFunc, layoutfuncname)
layout = []
num = 0
while True:
x = function(num)
if x < 0: break
layout.append(x)
num += 1
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.
def _generate_gen_anonymous_decl(self, tp, name):
if isinstance(tp, model.EnumType):
self._generate_gen_enum_decl(tp, name, '')
else:
self._generate_struct_or_union_decl(tp, '', name)
def _loading_gen_anonymous(self, tp, name, module):
if isinstance(tp, model.EnumType):
self._loading_gen_enum(tp, name, module, '')
else:
self._loading_struct_or_union(tp, '', name, module)
def _loaded_gen_anonymous(self, tp, name, module, **kwds):
if isinstance(tp, model.EnumType):
self._loaded_gen_enum(tp, name, module, **kwds)
else:
self._loaded_struct_or_union(tp)
# ----------
# constants, likely declared with '#define'
def _generate_gen_const(self, is_int, name, tp=None, category='const',
check_value=None):
prnt = self._prnt
funcname = '_cffi_%s_%s' % (category, name)
self.export_symbols.append(funcname)
if check_value is not None:
assert is_int
assert category == 'const'
prnt('int %s(char *out_error)' % funcname)
prnt('{')
self._check_int_constant_value(name, check_value)
prnt(' return 0;')
prnt('}')
elif is_int:
assert category == 'const'
prnt('int %s(long long *out_value)' % funcname)
prnt('{')
prnt(' *out_value = (long long)(%s);' % (name,))
prnt(' return (%s) <= 0;' % (name,))
prnt('}')
else:
assert tp is not None
assert check_value is None
if category == 'var':
ampersand = '&'
else:
ampersand = ''
extra = ''
if category == 'const' and isinstance(tp, model.StructOrUnion):
extra = 'const *'
ampersand = '&'
prnt(tp.get_c_name(' %s%s(void)' % (extra, funcname), name))
prnt('{')
prnt(' return (%s%s);' % (ampersand, name))
prnt('}')
prnt()
def _generate_gen_constant_decl(self, tp, name):
is_int = isinstance(tp, model.PrimitiveType) and tp.is_integer_type()
self._generate_gen_const(is_int, name, tp)
_loading_gen_constant = _loaded_noop
def _load_constant(self, is_int, tp, name, module, check_value=None):
funcname = '_cffi_const_%s' % name
if check_value is not None:
assert is_int
self._load_known_int_constant(module, funcname)
value = check_value
elif is_int:
BType = self.ffi._typeof_locked("long long*")[0]
BFunc = self.ffi._typeof_locked("int(*)(long long*)")[0]
function = module.load_function(BFunc, funcname)
p = self.ffi.new(BType)
negative = function(p)
value = int(p[0])
if value < 0 and not negative:
BLongLong = self.ffi._typeof_locked("long long")[0]
value += (1 << (8*self.ffi.sizeof(BLongLong)))
else:
assert check_value is None
fntypeextra = '(*)(void)'
if isinstance(tp, model.StructOrUnion):
fntypeextra = '*' + fntypeextra
BFunc = self.ffi._typeof_locked(tp.get_c_name(fntypeextra, name))[0]
function = module.load_function(BFunc, funcname)
value = function()
if isinstance(tp, model.StructOrUnion):
value = value[0]
return value
def _loaded_gen_constant(self, tp, name, module, library):
is_int = isinstance(tp, model.PrimitiveType) and tp.is_integer_type()
value = self._load_constant(is_int, tp, name, module)
setattr(library, name, value)
type(library)._cffi_dir.append(name)
# ----------
# enums
def _check_int_constant_value(self, name, value):
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(' sprintf(buf, "%%ld", (long)(%s));' % name)
prnt(' else')
prnt(' sprintf(buf, "%%lu", (unsigned long)(%s));' %
name)
prnt(' sprintf(out_error, "%s has the real value %s, not %s",')
prnt(' "%s", buf, "%d");' % (name[:100], value))
prnt(' return -1;')
prnt(' }')
def _load_known_int_constant(self, module, funcname):
BType = self.ffi._typeof_locked("char[]")[0]
BFunc = self.ffi._typeof_locked("int(*)(char*)")[0]
function = module.load_function(BFunc, funcname)
p = self.ffi.new(BType, 256)
if function(p) < 0:
error = self.ffi.string(p)
if sys.version_info >= (3,):
error = str(error, 'utf-8')
raise VerificationError(error)
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_gen_enum_decl(self, tp, name, prefix='enum'):
if tp.partial:
for enumerator in tp.enumerators:
self._generate_gen_const(True, enumerator)
return
#
funcname = self._enum_funcname(prefix, name)
self.export_symbols.append(funcname)
prnt = self._prnt
prnt('int %s(char *out_error)' % funcname)
prnt('{')
for enumerator, enumvalue in zip(tp.enumerators, tp.enumvalues):
self._check_int_constant_value(enumerator, enumvalue)
prnt(' return 0;')
prnt('}')
prnt()
def _loading_gen_enum(self, tp, name, module, prefix='enum'):
if tp.partial:
enumvalues = [self._load_constant(True, tp, enumerator, module)
for enumerator in tp.enumerators]
tp.enumvalues = tuple(enumvalues)
tp.partial_resolved = True
else:
funcname = self._enum_funcname(prefix, name)
self._load_known_int_constant(module, funcname)
def _loaded_gen_enum(self, tp, name, module, library):
for enumerator, enumvalue in zip(tp.enumerators, tp.enumvalues):
setattr(library, enumerator, enumvalue)
type(library)._cffi_dir.append(enumerator)
# ----------
# macros: for now only for integers
def _generate_gen_macro_decl(self, tp, name):
if tp == '...':
check_value = None
else:
check_value = tp # an integer
self._generate_gen_const(True, name, check_value=check_value)
_loading_gen_macro = _loaded_noop
def _loaded_gen_macro(self, tp, name, module, library):
if tp == '...':
check_value = None
else:
check_value = tp # an integer
value = self._load_constant(True, tp, name, module,
check_value=check_value)
setattr(library, name, value)
type(library)._cffi_dir.append(name)
# ----------
# global variables
def _generate_gen_variable_decl(self, tp, name):
if isinstance(tp, model.ArrayType):
if tp.length == '...':
prnt = self._prnt
funcname = '_cffi_sizeof_%s' % (name,)
self.export_symbols.append(funcname)
prnt("size_t %s(void)" % funcname)
prnt("{")
prnt(" return sizeof(%s);" % (name,))
prnt("}")
tp_ptr = model.PointerType(tp.item)
self._generate_gen_const(False, name, tp_ptr)
else:
tp_ptr = model.PointerType(tp)
self._generate_gen_const(False, name, tp_ptr, category='var')
_loading_gen_variable = _loaded_noop
def _loaded_gen_variable(self, tp, name, module, library):
if isinstance(tp, model.ArrayType): # int a[5] is "constant" in the
# sense that "a=..." is forbidden
if tp.length == '...':
funcname = '_cffi_sizeof_%s' % (name,)
BFunc = self.ffi._typeof_locked('size_t(*)(void)')[0]
function = module.load_function(BFunc, funcname)
size = function()
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)
tp_ptr = model.PointerType(tp.item)
value = self._load_constant(False, tp_ptr, name, module)
# '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)
type(library)._cffi_dir.append(name)
return
# remove ptr=<cdata 'int *'> from the library instance, and replace
# it by a property on the class, which reads/writes into ptr[0].
funcname = '_cffi_var_%s' % name
BFunc = self.ffi._typeof_locked(tp.get_c_name('*(*)(void)', name))[0]
function = module.load_function(BFunc, funcname)
ptr = function()
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)
cffimod_header = r'''
#include <stdio.h>
#include <stddef.h>
#include <stdarg.h>
#include <errno.h>
#include <sys/types.h> /* XXX for ssize_t on some platforms */
/* 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
#else
# include <stdint.h>
# if (defined (__SVR4) && defined (__sun)) || defined(_AIX) || defined(__hpux)
# include <alloca.h>
# endif
#endif
'''