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Diffstat (limited to 'cffi/api.py')
| -rw-r--r-- | cffi/api.py | 961 |
1 files changed, 961 insertions, 0 deletions
diff --git a/cffi/api.py b/cffi/api.py new file mode 100644 index 0000000..32fe620 --- /dev/null +++ b/cffi/api.py @@ -0,0 +1,961 @@ +import sys, types +from .lock import allocate_lock +from .error import CDefError +from . import model + +try: + callable +except NameError: + # Python 3.1 + from collections import Callable + callable = lambda x: isinstance(x, Callable) + +try: + basestring +except NameError: + # Python 3.x + basestring = str + +_unspecified = object() + + + +class FFI(object): + r''' + The main top-level class that you instantiate once, or once per module. + + Example usage: + + ffi = FFI() + ffi.cdef(""" + int printf(const char *, ...); + """) + + C = ffi.dlopen(None) # standard library + -or- + C = ffi.verify() # use a C compiler: verify the decl above is right + + C.printf("hello, %s!\n", ffi.new("char[]", "world")) + ''' + + def __init__(self, backend=None): + """Create an FFI instance. The 'backend' argument is used to + select a non-default backend, mostly for tests. + """ + if backend is None: + # You need PyPy (>= 2.0 beta), or a CPython (>= 2.6) with + # _cffi_backend.so compiled. + import _cffi_backend as backend + from . import __version__ + if backend.__version__ != __version__: + # bad version! Try to be as explicit as possible. + if hasattr(backend, '__file__'): + # CPython + raise Exception("Version mismatch: this is the 'cffi' package version %s, located in %r. When we import the top-level '_cffi_backend' extension module, we get version %s, located in %r. The two versions should be equal; check your installation." % ( + __version__, __file__, + backend.__version__, backend.__file__)) + else: + # PyPy + raise Exception("Version mismatch: this is the 'cffi' package version %s, located in %r. This interpreter comes with a built-in '_cffi_backend' module, which is version %s. The two versions should be equal; check your installation." % ( + __version__, __file__, backend.__version__)) + # (If you insist you can also try to pass the option + # 'backend=backend_ctypes.CTypesBackend()', but don't + # rely on it! It's probably not going to work well.) + + from . import cparser + self._backend = backend + self._lock = allocate_lock() + self._parser = cparser.Parser() + self._cached_btypes = {} + self._parsed_types = types.ModuleType('parsed_types').__dict__ + self._new_types = types.ModuleType('new_types').__dict__ + self._function_caches = [] + self._libraries = [] + self._cdefsources = [] + self._included_ffis = [] + self._windows_unicode = None + self._init_once_cache = {} + self._cdef_version = None + self._embedding = None + self._typecache = model.get_typecache(backend) + if hasattr(backend, 'set_ffi'): + backend.set_ffi(self) + for name in list(backend.__dict__): + if name.startswith('RTLD_'): + setattr(self, name, getattr(backend, name)) + # + with self._lock: + self.BVoidP = self._get_cached_btype(model.voidp_type) + self.BCharA = self._get_cached_btype(model.char_array_type) + if isinstance(backend, types.ModuleType): + # _cffi_backend: attach these constants to the class + if not hasattr(FFI, 'NULL'): + FFI.NULL = self.cast(self.BVoidP, 0) + FFI.CData, FFI.CType = backend._get_types() + else: + # ctypes backend: attach these constants to the instance + self.NULL = self.cast(self.BVoidP, 0) + self.CData, self.CType = backend._get_types() + self.buffer = backend.buffer + + def cdef(self, csource, override=False, packed=False, pack=None): + """Parse the given C source. This registers all declared functions, + types, and global variables. The functions and global variables can + then be accessed via either 'ffi.dlopen()' or 'ffi.verify()'. + The types can be used in 'ffi.new()' and other functions. + If 'packed' is specified as True, all structs declared inside this + cdef are packed, i.e. laid out without any field alignment at all. + Alternatively, 'pack' can be a small integer, and requests for + alignment greater than that are ignored (pack=1 is equivalent to + packed=True). + """ + self._cdef(csource, override=override, packed=packed, pack=pack) + + def embedding_api(self, csource, packed=False, pack=None): + self._cdef(csource, packed=packed, pack=pack, dllexport=True) + if self._embedding is None: + self._embedding = '' + + def _cdef(self, csource, override=False, **options): + if not isinstance(csource, str): # unicode, on Python 2 + if not isinstance(csource, basestring): + raise TypeError("cdef() argument must be a string") + csource = csource.encode('ascii') + with self._lock: + self._cdef_version = object() + self._parser.parse(csource, override=override, **options) + self._cdefsources.append(csource) + if override: + for cache in self._function_caches: + cache.clear() + finishlist = self._parser._recomplete + if finishlist: + self._parser._recomplete = [] + for tp in finishlist: + tp.finish_backend_type(self, finishlist) + + def dlopen(self, name, flags=0): + """Load and return a dynamic library identified by 'name'. + The standard C library can be loaded by passing None. + Note that functions and types declared by 'ffi.cdef()' are not + linked to a particular library, just like C headers; in the + library we only look for the actual (untyped) symbols. + """ + assert isinstance(name, basestring) or name is None + with self._lock: + lib, function_cache = _make_ffi_library(self, name, flags) + self._function_caches.append(function_cache) + self._libraries.append(lib) + return lib + + def dlclose(self, lib): + """Close a library obtained with ffi.dlopen(). After this call, + access to functions or variables from the library will fail + (possibly with a segmentation fault). + """ + type(lib).__cffi_close__(lib) + + def _typeof_locked(self, cdecl): + # call me with the lock! + key = cdecl + if key in self._parsed_types: + return self._parsed_types[key] + # + if not isinstance(cdecl, str): # unicode, on Python 2 + cdecl = cdecl.encode('ascii') + # + type = self._parser.parse_type(cdecl) + really_a_function_type = type.is_raw_function + if really_a_function_type: + type = type.as_function_pointer() + btype = self._get_cached_btype(type) + result = btype, really_a_function_type + self._parsed_types[key] = result + return result + + def _typeof(self, cdecl, consider_function_as_funcptr=False): + # string -> ctype object + try: + result = self._parsed_types[cdecl] + except KeyError: + with self._lock: + result = self._typeof_locked(cdecl) + # + btype, really_a_function_type = result + if really_a_function_type and not consider_function_as_funcptr: + raise CDefError("the type %r is a function type, not a " + "pointer-to-function type" % (cdecl,)) + return btype + + def typeof(self, cdecl): + """Parse the C type given as a string and return the + corresponding <ctype> object. + It can also be used on 'cdata' instance to get its C type. + """ + if isinstance(cdecl, basestring): + return self._typeof(cdecl) + if isinstance(cdecl, self.CData): + return self._backend.typeof(cdecl) + if isinstance(cdecl, types.BuiltinFunctionType): + res = _builtin_function_type(cdecl) + if res is not None: + return res + if (isinstance(cdecl, types.FunctionType) + and hasattr(cdecl, '_cffi_base_type')): + with self._lock: + return self._get_cached_btype(cdecl._cffi_base_type) + raise TypeError(type(cdecl)) + + def sizeof(self, cdecl): + """Return the size in bytes of the argument. It can be a + string naming a C type, or a 'cdata' instance. + """ + if isinstance(cdecl, basestring): + BType = self._typeof(cdecl) + return self._backend.sizeof(BType) + else: + return self._backend.sizeof(cdecl) + + def alignof(self, cdecl): + """Return the natural alignment size in bytes of the C type + given as a string. + """ + if isinstance(cdecl, basestring): + cdecl = self._typeof(cdecl) + return self._backend.alignof(cdecl) + + def offsetof(self, cdecl, *fields_or_indexes): + """Return the offset of the named field inside the given + structure or array, which must be given as a C type name. + You can give several field names in case of nested structures. + You can also give numeric values which correspond to array + items, in case of an array type. + """ + if isinstance(cdecl, basestring): + cdecl = self._typeof(cdecl) + return self._typeoffsetof(cdecl, *fields_or_indexes)[1] + + def new(self, cdecl, init=None): + """Allocate an instance according to the specified C type and + return a pointer to it. The specified C type must be either a + pointer or an array: ``new('X *')`` allocates an X and returns + a pointer to it, whereas ``new('X[n]')`` allocates an array of + n X'es and returns an array referencing it (which works + mostly like a pointer, like in C). You can also use + ``new('X[]', n)`` to allocate an array of a non-constant + length n. + + The memory is initialized following the rules of declaring a + global variable in C: by default it is zero-initialized, but + an explicit initializer can be given which can be used to + fill all or part of the memory. + + When the returned <cdata> object goes out of scope, the memory + is freed. In other words the returned <cdata> object has + ownership of the value of type 'cdecl' that it points to. This + means that the raw data can be used as long as this object is + kept alive, but must not be used for a longer time. Be careful + about that when copying the pointer to the memory somewhere + else, e.g. into another structure. + """ + if isinstance(cdecl, basestring): + cdecl = self._typeof(cdecl) + return self._backend.newp(cdecl, init) + + def new_allocator(self, alloc=None, free=None, + should_clear_after_alloc=True): + """Return a new allocator, i.e. a function that behaves like ffi.new() + but uses the provided low-level 'alloc' and 'free' functions. + + 'alloc' is called with the size as argument. If it returns NULL, a + MemoryError is raised. 'free' is called with the result of 'alloc' + as argument. Both can be either Python function or directly C + functions. If 'free' is None, then no free function is called. + If both 'alloc' and 'free' are None, the default is used. + + If 'should_clear_after_alloc' is set to False, then the memory + returned by 'alloc' is assumed to be already cleared (or you are + fine with garbage); otherwise CFFI will clear it. + """ + compiled_ffi = self._backend.FFI() + allocator = compiled_ffi.new_allocator(alloc, free, + should_clear_after_alloc) + def allocate(cdecl, init=None): + if isinstance(cdecl, basestring): + cdecl = self._typeof(cdecl) + return allocator(cdecl, init) + return allocate + + def cast(self, cdecl, source): + """Similar to a C cast: returns an instance of the named C + type initialized with the given 'source'. The source is + casted between integers or pointers of any type. + """ + if isinstance(cdecl, basestring): + cdecl = self._typeof(cdecl) + return self._backend.cast(cdecl, source) + + def string(self, cdata, maxlen=-1): + """Return a Python string (or unicode string) from the 'cdata'. + If 'cdata' is a pointer or array of characters or bytes, returns + the null-terminated string. The returned string extends until + the first null character, or at most 'maxlen' characters. If + 'cdata' is an array then 'maxlen' defaults to its length. + + If 'cdata' is a pointer or array of wchar_t, returns a unicode + string following the same rules. + + If 'cdata' is a single character or byte or a wchar_t, returns + it as a string or unicode string. + + If 'cdata' is an enum, returns the value of the enumerator as a + string, or 'NUMBER' if the value is out of range. + """ + return self._backend.string(cdata, maxlen) + + def unpack(self, cdata, length): + """Unpack an array of C data of the given length, + returning a Python string/unicode/list. + + If 'cdata' is a pointer to 'char', returns a byte string. + It does not stop at the first null. This is equivalent to: + ffi.buffer(cdata, length)[:] + + If 'cdata' is a pointer to 'wchar_t', returns a unicode string. + 'length' is measured in wchar_t's; it is not the size in bytes. + + If 'cdata' is a pointer to anything else, returns a list of + 'length' items. This is a faster equivalent to: + [cdata[i] for i in range(length)] + """ + return self._backend.unpack(cdata, length) + + #def buffer(self, cdata, size=-1): + # """Return a read-write buffer object that references the raw C data + # pointed to by the given 'cdata'. The 'cdata' must be a pointer or + # an array. Can be passed to functions expecting a buffer, or directly + # manipulated with: + # + # buf[:] get a copy of it in a regular string, or + # buf[idx] as a single character + # buf[:] = ... + # buf[idx] = ... change the content + # """ + # note that 'buffer' is a type, set on this instance by __init__ + + def from_buffer(self, cdecl, python_buffer=_unspecified, + require_writable=False): + """Return a cdata of the given type pointing to the data of the + given Python object, which must support the buffer interface. + Note that this is not meant to be used on the built-in types + str or unicode (you can build 'char[]' arrays explicitly) + but only on objects containing large quantities of raw data + in some other format, like 'array.array' or numpy arrays. + + The first argument is optional and default to 'char[]'. + """ + if python_buffer is _unspecified: + cdecl, python_buffer = self.BCharA, cdecl + elif isinstance(cdecl, basestring): + cdecl = self._typeof(cdecl) + return self._backend.from_buffer(cdecl, python_buffer, + require_writable) + + def memmove(self, dest, src, n): + """ffi.memmove(dest, src, n) copies n bytes of memory from src to dest. + + Like the C function memmove(), the memory areas may overlap; + apart from that it behaves like the C function memcpy(). + + 'src' can be any cdata ptr or array, or any Python buffer object. + 'dest' can be any cdata ptr or array, or a writable Python buffer + object. The size to copy, 'n', is always measured in bytes. + + Unlike other methods, this one supports all Python buffer including + byte strings and bytearrays---but it still does not support + non-contiguous buffers. + """ + return self._backend.memmove(dest, src, n) + + def callback(self, cdecl, python_callable=None, error=None, onerror=None): + """Return a callback object or a decorator making such a + callback object. 'cdecl' must name a C function pointer type. + The callback invokes the specified 'python_callable' (which may + be provided either directly or via a decorator). Important: the + callback object must be manually kept alive for as long as the + callback may be invoked from the C level. + """ + def callback_decorator_wrap(python_callable): + if not callable(python_callable): + raise TypeError("the 'python_callable' argument " + "is not callable") + return self._backend.callback(cdecl, python_callable, + error, onerror) + if isinstance(cdecl, basestring): + cdecl = self._typeof(cdecl, consider_function_as_funcptr=True) + if python_callable is None: + return callback_decorator_wrap # decorator mode + else: + return callback_decorator_wrap(python_callable) # direct mode + + def getctype(self, cdecl, replace_with=''): + """Return a string giving the C type 'cdecl', which may be itself + a string or a <ctype> object. If 'replace_with' is given, it gives + extra text to append (or insert for more complicated C types), like + a variable name, or '*' to get actually the C type 'pointer-to-cdecl'. + """ + if isinstance(cdecl, basestring): + cdecl = self._typeof(cdecl) + replace_with = replace_with.strip() + if (replace_with.startswith('*') + and '&[' in self._backend.getcname(cdecl, '&')): + replace_with = '(%s)' % replace_with + elif replace_with and not replace_with[0] in '[(': + replace_with = ' ' + replace_with + return self._backend.getcname(cdecl, replace_with) + + def gc(self, cdata, destructor, size=0): + """Return a new cdata object that points to the same + data. Later, when this new cdata object is garbage-collected, + 'destructor(old_cdata_object)' will be called. + + The optional 'size' gives an estimate of the size, used to + trigger the garbage collection more eagerly. So far only used + on PyPy. It tells the GC that the returned object keeps alive + roughly 'size' bytes of external memory. + """ + return self._backend.gcp(cdata, destructor, size) + + def _get_cached_btype(self, type): + assert self._lock.acquire(False) is False + # call me with the lock! + try: + BType = self._cached_btypes[type] + except KeyError: + finishlist = [] + BType = type.get_cached_btype(self, finishlist) + for type in finishlist: + type.finish_backend_type(self, finishlist) + return BType + + def verify(self, source='', tmpdir=None, **kwargs): + """Verify that the current ffi signatures compile on this + machine, and return a dynamic library object. The dynamic + library can be used to call functions and access global + variables declared in this 'ffi'. The library is compiled + by the C compiler: it gives you C-level API compatibility + (including calling macros). This is unlike 'ffi.dlopen()', + which requires binary compatibility in the signatures. + """ + from .verifier import Verifier, _caller_dir_pycache + # + # If set_unicode(True) was called, insert the UNICODE and + # _UNICODE macro declarations + if self._windows_unicode: + self._apply_windows_unicode(kwargs) + # + # Set the tmpdir here, and not in Verifier.__init__: it picks + # up the caller's directory, which we want to be the caller of + # ffi.verify(), as opposed to the caller of Veritier(). + tmpdir = tmpdir or _caller_dir_pycache() + # + # Make a Verifier() and use it to load the library. + self.verifier = Verifier(self, source, tmpdir, **kwargs) + lib = self.verifier.load_library() + # + # Save the loaded library for keep-alive purposes, even + # if the caller doesn't keep it alive itself (it should). + self._libraries.append(lib) + return lib + + def _get_errno(self): + return self._backend.get_errno() + def _set_errno(self, errno): + self._backend.set_errno(errno) + errno = property(_get_errno, _set_errno, None, + "the value of 'errno' from/to the C calls") + + def getwinerror(self, code=-1): + return self._backend.getwinerror(code) + + def _pointer_to(self, ctype): + with self._lock: + return model.pointer_cache(self, ctype) + + def addressof(self, cdata, *fields_or_indexes): + """Return the address of a <cdata 'struct-or-union'>. + If 'fields_or_indexes' are given, returns the address of that + field or array item in the structure or array, recursively in + case of nested structures. + """ + try: + ctype = self._backend.typeof(cdata) + except TypeError: + if '__addressof__' in type(cdata).__dict__: + return type(cdata).__addressof__(cdata, *fields_or_indexes) + raise + if fields_or_indexes: + ctype, offset = self._typeoffsetof(ctype, *fields_or_indexes) + else: + if ctype.kind == "pointer": + raise TypeError("addressof(pointer)") + offset = 0 + ctypeptr = self._pointer_to(ctype) + return self._backend.rawaddressof(ctypeptr, cdata, offset) + + def _typeoffsetof(self, ctype, field_or_index, *fields_or_indexes): + ctype, offset = self._backend.typeoffsetof(ctype, field_or_index) + for field1 in fields_or_indexes: + ctype, offset1 = self._backend.typeoffsetof(ctype, field1, 1) + offset += offset1 + return ctype, offset + + def include(self, ffi_to_include): + """Includes the typedefs, structs, unions and enums defined + in another FFI instance. Usage is similar to a #include in C, + where a part of the program might include types defined in + another part for its own usage. Note that the include() + method has no effect on functions, constants and global + variables, which must anyway be accessed directly from the + lib object returned by the original FFI instance. + """ + if not isinstance(ffi_to_include, FFI): + raise TypeError("ffi.include() expects an argument that is also of" + " type cffi.FFI, not %r" % ( + type(ffi_to_include).__name__,)) + if ffi_to_include is self: + raise ValueError("self.include(self)") + with ffi_to_include._lock: + with self._lock: + self._parser.include(ffi_to_include._parser) + self._cdefsources.append('[') + self._cdefsources.extend(ffi_to_include._cdefsources) + self._cdefsources.append(']') + self._included_ffis.append(ffi_to_include) + + def new_handle(self, x): + return self._backend.newp_handle(self.BVoidP, x) + + def from_handle(self, x): + return self._backend.from_handle(x) + + def release(self, x): + self._backend.release(x) + + def set_unicode(self, enabled_flag): + """Windows: if 'enabled_flag' is True, enable the UNICODE and + _UNICODE defines in C, and declare the types like TCHAR and LPTCSTR + to be (pointers to) wchar_t. If 'enabled_flag' is False, + declare these types to be (pointers to) plain 8-bit characters. + This is mostly for backward compatibility; you usually want True. + """ + if self._windows_unicode is not None: + raise ValueError("set_unicode() can only be called once") + enabled_flag = bool(enabled_flag) + if enabled_flag: + self.cdef("typedef wchar_t TBYTE;" + "typedef wchar_t TCHAR;" + "typedef const wchar_t *LPCTSTR;" + "typedef const wchar_t *PCTSTR;" + "typedef wchar_t *LPTSTR;" + "typedef wchar_t *PTSTR;" + "typedef TBYTE *PTBYTE;" + "typedef TCHAR *PTCHAR;") + else: + self.cdef("typedef char TBYTE;" + "typedef char TCHAR;" + "typedef const char *LPCTSTR;" + "typedef const char *PCTSTR;" + "typedef char *LPTSTR;" + "typedef char *PTSTR;" + "typedef TBYTE *PTBYTE;" + "typedef TCHAR *PTCHAR;") + self._windows_unicode = enabled_flag + + def _apply_windows_unicode(self, kwds): + defmacros = kwds.get('define_macros', ()) + if not isinstance(defmacros, (list, tuple)): + raise TypeError("'define_macros' must be a list or tuple") + defmacros = list(defmacros) + [('UNICODE', '1'), + ('_UNICODE', '1')] + kwds['define_macros'] = defmacros + + def _apply_embedding_fix(self, kwds): + # must include an argument like "-lpython2.7" for the compiler + def ensure(key, value): + lst = kwds.setdefault(key, []) + if value not in lst: + lst.append(value) + # + if '__pypy__' in sys.builtin_module_names: + import os + if sys.platform == "win32": + # we need 'libpypy-c.lib'. Current distributions of + # pypy (>= 4.1) contain it as 'libs/python27.lib'. + pythonlib = "python{0[0]}{0[1]}".format(sys.version_info) + if hasattr(sys, 'prefix'): + ensure('library_dirs', os.path.join(sys.prefix, 'libs')) + else: + # we need 'libpypy-c.{so,dylib}', which should be by + # default located in 'sys.prefix/bin' for installed + # systems. + if sys.version_info < (3,): + pythonlib = "pypy-c" + else: + pythonlib = "pypy3-c" + if hasattr(sys, 'prefix'): + ensure('library_dirs', os.path.join(sys.prefix, 'bin')) + # On uninstalled pypy's, the libpypy-c is typically found in + # .../pypy/goal/. + if hasattr(sys, 'prefix'): + ensure('library_dirs', os.path.join(sys.prefix, 'pypy', 'goal')) + else: + if sys.platform == "win32": + template = "python%d%d" + if hasattr(sys, 'gettotalrefcount'): + template += '_d' + else: + try: + import sysconfig + except ImportError: # 2.6 + from distutils import sysconfig + template = "python%d.%d" + if sysconfig.get_config_var('DEBUG_EXT'): + template += sysconfig.get_config_var('DEBUG_EXT') + pythonlib = (template % + (sys.hexversion >> 24, (sys.hexversion >> 16) & 0xff)) + if hasattr(sys, 'abiflags'): + pythonlib += sys.abiflags + ensure('libraries', pythonlib) + if sys.platform == "win32": + ensure('extra_link_args', '/MANIFEST') + + def set_source(self, module_name, source, source_extension='.c', **kwds): + import os + if hasattr(self, '_assigned_source'): + raise ValueError("set_source() cannot be called several times " + "per ffi object") + if not isinstance(module_name, basestring): + raise TypeError("'module_name' must be a string") + if os.sep in module_name or (os.altsep and os.altsep in module_name): + raise ValueError("'module_name' must not contain '/': use a dotted " + "name to make a 'package.module' location") + self._assigned_source = (str(module_name), source, + source_extension, kwds) + + def set_source_pkgconfig(self, module_name, pkgconfig_libs, source, + source_extension='.c', **kwds): + from . import pkgconfig + if not isinstance(pkgconfig_libs, list): + raise TypeError("the pkgconfig_libs argument must be a list " + "of package names") + kwds2 = pkgconfig.flags_from_pkgconfig(pkgconfig_libs) + pkgconfig.merge_flags(kwds, kwds2) + self.set_source(module_name, source, source_extension, **kwds) + + def distutils_extension(self, tmpdir='build', verbose=True): + from distutils.dir_util import mkpath + from .recompiler import recompile + # + if not hasattr(self, '_assigned_source'): + if hasattr(self, 'verifier'): # fallback, 'tmpdir' ignored + return self.verifier.get_extension() + raise ValueError("set_source() must be called before" + " distutils_extension()") + module_name, source, source_extension, kwds = self._assigned_source + if source is None: + raise TypeError("distutils_extension() is only for C extension " + "modules, not for dlopen()-style pure Python " + "modules") + mkpath(tmpdir) + ext, updated = recompile(self, module_name, + source, tmpdir=tmpdir, extradir=tmpdir, + source_extension=source_extension, + call_c_compiler=False, **kwds) + if verbose: + if updated: + sys.stderr.write("regenerated: %r\n" % (ext.sources[0],)) + else: + sys.stderr.write("not modified: %r\n" % (ext.sources[0],)) + return ext + + def emit_c_code(self, filename): + from .recompiler import recompile + # + if not hasattr(self, '_assigned_source'): + raise ValueError("set_source() must be called before emit_c_code()") + module_name, source, source_extension, kwds = self._assigned_source + if source is None: + raise TypeError("emit_c_code() is only for C extension modules, " + "not for dlopen()-style pure Python modules") + recompile(self, module_name, source, + c_file=filename, call_c_compiler=False, **kwds) + + def emit_python_code(self, filename): + from .recompiler import recompile + # + if not hasattr(self, '_assigned_source'): + raise ValueError("set_source() must be called before emit_c_code()") + module_name, source, source_extension, kwds = self._assigned_source + if source is not None: + raise TypeError("emit_python_code() is only for dlopen()-style " + "pure Python modules, not for C extension modules") + recompile(self, module_name, source, + c_file=filename, call_c_compiler=False, **kwds) + + def compile(self, tmpdir='.', verbose=0, target=None, debug=None): + """The 'target' argument gives the final file name of the + compiled DLL. Use '*' to force distutils' choice, suitable for + regular CPython C API modules. Use a file name ending in '.*' + to ask for the system's default extension for dynamic libraries + (.so/.dll/.dylib). + + The default is '*' when building a non-embedded C API extension, + and (module_name + '.*') when building an embedded library. + """ + from .recompiler import recompile + # + if not hasattr(self, '_assigned_source'): + raise ValueError("set_source() must be called before compile()") + module_name, source, source_extension, kwds = self._assigned_source + return recompile(self, module_name, source, tmpdir=tmpdir, + target=target, source_extension=source_extension, + compiler_verbose=verbose, debug=debug, **kwds) + + def init_once(self, func, tag): + # Read _init_once_cache[tag], which is either (False, lock) if + # we're calling the function now in some thread, or (True, result). + # Don't call setdefault() in most cases, to avoid allocating and + # immediately freeing a lock; but still use setdefaut() to avoid + # races. + try: + x = self._init_once_cache[tag] + except KeyError: + x = self._init_once_cache.setdefault(tag, (False, allocate_lock())) + # Common case: we got (True, result), so we return the result. + if x[0]: + return x[1] + # Else, it's a lock. Acquire it to serialize the following tests. + with x[1]: + # Read again from _init_once_cache the current status. + x = self._init_once_cache[tag] + if x[0]: + return x[1] + # Call the function and store the result back. + result = func() + self._init_once_cache[tag] = (True, result) + return result + + def embedding_init_code(self, pysource): + if self._embedding: + raise ValueError("embedding_init_code() can only be called once") + # fix 'pysource' before it gets dumped into the C file: + # - remove empty lines at the beginning, so it starts at "line 1" + # - dedent, if all non-empty lines are indented + # - check for SyntaxErrors + import re + match = re.match(r'\s*\n', pysource) + if match: + pysource = pysource[match.end():] + lines = pysource.splitlines() or [''] + prefix = re.match(r'\s*', lines[0]).group() + for i in range(1, len(lines)): + line = lines[i] + if line.rstrip(): + while not line.startswith(prefix): + prefix = prefix[:-1] + i = len(prefix) + lines = [line[i:]+'\n' for line in lines] + pysource = ''.join(lines) + # + compile(pysource, "cffi_init", "exec") + # + self._embedding = pysource + + def def_extern(self, *args, **kwds): + raise ValueError("ffi.def_extern() is only available on API-mode FFI " + "objects") + + def list_types(self): + """Returns the user type names known to this FFI instance. + This returns a tuple containing three lists of names: + (typedef_names, names_of_structs, names_of_unions) + """ + typedefs = [] + structs = [] + unions = [] + for key in self._parser._declarations: + if key.startswith('typedef '): + typedefs.append(key[8:]) + elif key.startswith('struct '): + structs.append(key[7:]) + elif key.startswith('union '): + unions.append(key[6:]) + typedefs.sort() + structs.sort() + unions.sort() + return (typedefs, structs, unions) + + +def _load_backend_lib(backend, name, flags): + import os + if name is None: + if sys.platform != "win32": + return backend.load_library(None, flags) + name = "c" # Windows: load_library(None) fails, but this works + # on Python 2 (backward compatibility hack only) + first_error = None + if '.' in name or '/' in name or os.sep in name: + try: + return backend.load_library(name, flags) + except OSError as e: + first_error = e + import ctypes.util + path = ctypes.util.find_library(name) + if path is None: + if name == "c" and sys.platform == "win32" and sys.version_info >= (3,): + raise OSError("dlopen(None) cannot work on Windows for Python 3 " + "(see http://bugs.python.org/issue23606)") + msg = ("ctypes.util.find_library() did not manage " + "to locate a library called %r" % (name,)) + if first_error is not None: + msg = "%s. Additionally, %s" % (first_error, msg) + raise OSError(msg) + return backend.load_library(path, flags) + +def _make_ffi_library(ffi, libname, flags): + backend = ffi._backend + backendlib = _load_backend_lib(backend, libname, flags) + # + def accessor_function(name): + key = 'function ' + name + tp, _ = ffi._parser._declarations[key] + BType = ffi._get_cached_btype(tp) + value = backendlib.load_function(BType, name) + library.__dict__[name] = value + # + def accessor_variable(name): + key = 'variable ' + name + tp, _ = ffi._parser._declarations[key] + BType = ffi._get_cached_btype(tp) + read_variable = backendlib.read_variable + write_variable = backendlib.write_variable + setattr(FFILibrary, name, property( + lambda self: read_variable(BType, name), + lambda self, value: write_variable(BType, name, value))) + # + def addressof_var(name): + try: + return addr_variables[name] + except KeyError: + with ffi._lock: + if name not in addr_variables: + key = 'variable ' + name + tp, _ = ffi._parser._declarations[key] + BType = ffi._get_cached_btype(tp) + if BType.kind != 'array': + BType = model.pointer_cache(ffi, BType) + p = backendlib.load_function(BType, name) + addr_variables[name] = p + return addr_variables[name] + # + def accessor_constant(name): + raise NotImplementedError("non-integer constant '%s' cannot be " + "accessed from a dlopen() library" % (name,)) + # + def accessor_int_constant(name): + library.__dict__[name] = ffi._parser._int_constants[name] + # + accessors = {} + accessors_version = [False] + addr_variables = {} + # + def update_accessors(): + if accessors_version[0] is ffi._cdef_version: + return + # + for key, (tp, _) in ffi._parser._declarations.items(): + if not isinstance(tp, model.EnumType): + tag, name = key.split(' ', 1) + if tag == 'function': + accessors[name] = accessor_function + elif tag == 'variable': + accessors[name] = accessor_variable + elif tag == 'constant': + accessors[name] = accessor_constant + else: + for i, enumname in enumerate(tp.enumerators): + def accessor_enum(name, tp=tp, i=i): + tp.check_not_partial() + library.__dict__[name] = tp.enumvalues[i] + accessors[enumname] = accessor_enum + for name in ffi._parser._int_constants: + accessors.setdefault(name, accessor_int_constant) + accessors_version[0] = ffi._cdef_version + # + def make_accessor(name): + with ffi._lock: + if name in library.__dict__ or name in FFILibrary.__dict__: + return # added by another thread while waiting for the lock + if name not in accessors: + update_accessors() + if name not in accessors: + raise AttributeError(name) + accessors[name](name) + # + class FFILibrary(object): + def __getattr__(self, name): + make_accessor(name) + return getattr(self, name) + def __setattr__(self, name, value): + try: + property = getattr(self.__class__, name) + except AttributeError: + make_accessor(name) + setattr(self, name, value) + else: + property.__set__(self, value) + def __dir__(self): + with ffi._lock: + update_accessors() + return accessors.keys() + def __addressof__(self, name): + if name in library.__dict__: + return library.__dict__[name] + if name in FFILibrary.__dict__: + return addressof_var(name) + make_accessor(name) + if name in library.__dict__: + return library.__dict__[name] + if name in FFILibrary.__dict__: + return addressof_var(name) + raise AttributeError("cffi library has no function or " + "global variable named '%s'" % (name,)) + def __cffi_close__(self): + backendlib.close_lib() + self.__dict__.clear() + # + if libname is not None: + try: + if not isinstance(libname, str): # unicode, on Python 2 + libname = libname.encode('utf-8') + FFILibrary.__name__ = 'FFILibrary_%s' % libname + except UnicodeError: + pass + library = FFILibrary() + return library, library.__dict__ + +def _builtin_function_type(func): + # a hack to make at least ffi.typeof(builtin_function) work, + # if the builtin function was obtained by 'vengine_cpy'. + import sys + try: + module = sys.modules[func.__module__] + ffi = module._cffi_original_ffi + types_of_builtin_funcs = module._cffi_types_of_builtin_funcs + tp = types_of_builtin_funcs[func] + except (KeyError, AttributeError, TypeError): + return None + else: + with ffi._lock: + return ffi._get_cached_btype(tp) |