diff options
Diffstat (limited to 'cffi/vengine_gen.py')
| -rw-r--r-- | cffi/vengine_gen.py | 675 |
1 files changed, 675 insertions, 0 deletions
diff --git a/cffi/vengine_gen.py b/cffi/vengine_gen.py new file mode 100644 index 0000000..a64ff64 --- /dev/null +++ b/cffi/vengine_gen.py @@ -0,0 +1,675 @@ +# +# 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 +''' |