← Back
Editing: vengine_gen.py
# # 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_is_unknown(): 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_is_unknown(): 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 '''
Save File
Cancel