====================== What's New ====================== v1.12.2 ======= * Added temporary workaround to compile on CPython 3.8.0a2. v1.12.1 ======= * CPython 3 on Windows: we again no longer compile with ``Py_LIMITED_API`` by default because such modules *still* cannot be used with virtualenv. The problem is that it doesn't work in CPython <= 3.4, and for technical reason we can't enable this flag automatically based on the version of Python. Like before, `Issue #350`_ mentions a workaround if you still want the ``Py_LIMITED_API`` flag and *either* you are not concerned about virtualenv *or* you are sure your module will not be used on CPython <= 3.4: pass ``define_macros=[("Py_LIMITED_API", None)]`` to the ``ffibuilder.set_source()`` call. v1.12 ===== * `Direct support for pkg-config`__. * ``ffi.from_buffer()`` takes a new optional *first* argument that gives the array type of the result. It also takes an optional keyword argument ``require_writable`` to refuse read-only Python buffers. * ``ffi.new()``, ``ffi.gc()`` or ``ffi.from_buffer()`` cdata objects can now be released at known times, either by using the ``with`` keyword or by calling the new ``ffi.release()``. * Windows, CPython 3.x: cffi modules are linked with ``python3.dll`` again. This makes them independant on the exact CPython version, like they are on other platforms. **It requires virtualenv 16.0.0.** * Accept an expression like ``ffi.new("int[4]", p)`` if ``p`` is itself another cdata ``int[4]``. * CPython 2.x: ``ffi.dlopen()`` failed with non-ascii file names on Posix * CPython: if a thread is started from C and then runs Python code (with callbacks or with the embedding solution), then previous versions of cffi would contain possible crashes and/or memory leaks. Hopefully, this has been fixed (see `issue #362`_). * Support for ``ffi.cdef(..., pack=N)`` where N is a power of two. Means to emulate ``#pragma pack(N)`` on MSVC. Also, the default on Windows is now ``pack=8``, like on MSVC. This might make a difference in corner cases, although I can't think of one in the context of CFFI. The old way ``ffi.cdef(..., packed=True)`` remains and is equivalent to ``pack=1`` (saying e.g. that fields like ``int`` should be aligned to 1 byte instead of 4). .. __: cdef.html#pkgconfig .. _`issue #362`: https://bitbucket.org/cffi/cffi/issues/362/ Older Versions ============== v1.11.5 ------- * `Issue #357`_: fix ``ffi.emit_python_code()`` which generated a buggy Python file if you are using a ``struct`` with an anonymous ``union`` field or vice-versa. * Windows: ``ffi.dlopen()`` should now handle unicode filenames. * ABI mode: implemented ``ffi.dlclose()`` for the in-line case (it used to be present only in the out-of-line case). * Fixed a corner case for ``setup.py install --record=xx --root=yy`` with an out-of-line ABI module. Also fixed `Issue #345`_. * More hacks on Windows for running CFFI's own ``setup.py``. * `Issue #358`_: in embedding, to protect against (the rare case of) Python initialization from several threads in parallel, we have to use a spin-lock. On CPython 3 it is worse because it might spin-lock for a long time (execution of ``Py_InitializeEx()``). Sadly, recent changes to CPython make that solution needed on CPython 2 too. * CPython 3 on Windows: we no longer compile with ``Py_LIMITED_API`` by default because such modules cannot be used with virtualenv. `Issue #350`_ mentions a workaround if you still want that and are not concerned about virtualenv: pass a ``define_macros=[("Py_LIMITED_API", None)]`` to the ``ffibuilder.set_source()`` call. .. _`Issue #345`: https://bitbucket.org/cffi/cffi/issues/345/ .. _`Issue #350`: https://bitbucket.org/cffi/cffi/issues/350/ .. _`Issue #358`: https://bitbucket.org/cffi/cffi/issues/358/ .. _`Issue #357`: https://bitbucket.org/cffi/cffi/issues/357/ v1.11.4 ------- * Windows: reverted linking with ``python3.dll``, because virtualenv does not make this DLL available to virtual environments for now. See `Issue #355`_. On Windows only, the C extension modules created by cffi follow for now the standard naming scheme ``foo.cp36-win32.pyd``, to make it clear that they are regular CPython modules depending on ``python36.dll``. .. _`Issue #355`: https://bitbucket.org/cffi/cffi/issues/355/ v1.11.3 ------- * Fix on CPython 3.x: reading the attributes ``__loader__`` or ``__spec__`` from the cffi-generated lib modules gave a buggy SystemError. (These attributes are always None, and provided only to help compatibility with tools that expect them in all modules.) * More Windows fixes: workaround for MSVC not supporting large literal strings in C code (from ``ffi.embedding_init_code(large_string)``); and an issue with ``Py_LIMITED_API`` linking with ``python35.dll/python36.dll`` instead of ``python3.dll``. * Small documentation improvements. v1.11.2 ------- * Fix Windows issue with managing the thread-state on CPython 3.0 to 3.5 v1.11.1 ------- * Fix tests, remove deprecated C API usage * Fix (hack) for 3.6.0/3.6.1/3.6.2 giving incompatible binary extensions (cpython issue `#29943`_) * Fix for 3.7.0a1+ .. _`#29943`: https://bugs.python.org/issue29943 v1.11 ----- * Support the modern standard types ``char16_t`` and ``char32_t``. These work like ``wchar_t``: they represent one unicode character, or when used as ``charN_t *`` or ``charN_t[]`` they represent a unicode string. The difference with ``wchar_t`` is that they have a known, fixed size. They should work at all places that used to work with ``wchar_t`` (please report an issue if I missed something). Note that with ``set_source()``, you need to make sure that these types are actually defined by the C source you provide (if used in ``cdef()``). * Support the C99 types ``float _Complex`` and ``double _Complex``. Note that libffi doesn't support them, which means that in the ABI mode you still cannot call C functions that take complex numbers directly as arguments or return type. * Fixed a rare race condition when creating multiple ``FFI`` instances from multiple threads. (Note that you aren't meant to create many ``FFI`` instances: in inline mode, you should write ``ffi = cffi.FFI()`` at module level just after ``import cffi``; and in out-of-line mode you don't instantiate ``FFI`` explicitly at all.) * Windows: using callbacks can be messy because the CFFI internal error messages show up to stderr---but stderr goes nowhere in many applications. This makes it particularly hard to get started with the embedding mode. (Once you get started, you can at least use ``@ffi.def_extern(onerror=...)`` and send the error logs where it makes sense for your application, or record them in log files, and so on.) So what is new in CFFI is that now, on Windows CFFI will try to open a non-modal MessageBox (in addition to sending raw messages to stderr). The MessageBox is only visible if the process stays alive: typically, console applications that crash close immediately, but that is also the situation where stderr should be visible anyway. * Progress on support for `callbacks in NetBSD`__. * Functions returning booleans would in some case still return 0 or 1 instead of False or True. Fixed. * `ffi.gc()`__ now takes an optional third parameter, which gives an estimate of the size (in bytes) of the object. So far, this is only used by PyPy, to make the next GC occur more quickly (`issue #320`__). In the future, this might have an effect on CPython too (provided the CPython `issue 31105`__ is addressed). * Add a note to the documentation: the ABI mode gives function objects that are *slower* to call than the API mode does. For some reason it is often thought to be faster. It is not! .. __: https://bitbucket.org/cffi/cffi/issues/321/cffi-191-segmentation-fault-during-self .. __: ref.html#ffi-gc .. __: https://bitbucket.org/cffi/cffi/issues/320/improve-memory_pressure-management .. __: http://bugs.python.org/issue31105 v1.10.1 ------- (only released inside PyPy 5.8.0) * Fixed the line numbers reported in case of ``cdef()`` errors. Also, I just noticed, but pycparser always supported the preprocessor directive ``# 42 "foo.h"`` to mean "from the next line, we're in file foo.h starting from line 42", which it puts in the error messages. v1.10 ----- * Issue #295: use calloc() directly instead of PyObject_Malloc()+memset() to handle ffi.new() with a default allocator. Speeds up ``ffi.new(large-array)`` where most of the time you never touch most of the array. * Some OS/X build fixes ("only with Xcode but without CLT"). * Improve a couple of error messages: when getting mismatched versions of cffi and its backend; and when calling functions which cannot be called with libffi because an argument is a struct that is "too complicated" (and not a struct *pointer*, which always works). * Add support for some unusual compilers (non-msvc, non-gcc, non-icc, non-clang) * Implemented the remaining cases for ``ffi.from_buffer``. Now all buffer/memoryview objects can be passed. The one remaining check is against passing unicode strings in Python 2. (They support the buffer interface, but that gives the raw bytes behind the UTF16/UCS4 storage, which is most of the times not what you expect. In Python 3 this has been fixed and the unicode strings don't support the memoryview interface any more.) * The C type ``_Bool`` or ``bool`` now converts to a Python boolean when reading, instead of the content of the byte as an integer. The potential incompatibility here is what occurs if the byte contains a value different from 0 and 1. Previously, it would just return it; with this change, CFFI raises an exception in this case. But this case means "undefined behavior" in C; if you really have to interface with a library relying on this, don't use ``bool`` in the CFFI side. Also, it is still valid to use a byte string as initializer for a ``bool[]``, but now it must only contain ``\x00`` or ``\x01``. As an aside, ``ffi.string()`` no longer works on ``bool[]`` (but it never made much sense, as this function stops at the first zero). * ``ffi.buffer`` is now the name of cffi's buffer type, and ``ffi.buffer()`` works like before but is the constructor of that type. * ``ffi.addressof(lib, "name")`` now works also in in-line mode, not only in out-of-line mode. This is useful for taking the address of global variables. * Issue #255: ``cdata`` objects of a primitive type (integers, floats, char) are now compared and ordered by value. For example, ```` compares equal to ``42`` and ```` compares equal to ``b'A'``. Unlike C, ```` does not compare equal to ``ffi.cast("unsigned int", -1)``: it compares smaller, because ``-1 < 4294967295``. * PyPy: ``ffi.new()`` and ``ffi.new_allocator()()`` did not record "memory pressure", causing the GC to run too infrequently if you call ``ffi.new()`` very often and/or with large arrays. Fixed in PyPy 5.7. * Support in ``ffi.cdef()`` for numeric expressions with ``+`` or ``-``. Assumes that there is no overflow; it should be fixed first before we add more general support for arbitrary arithmetic on constants. v1.9 ---- * Structs with variable-sized arrays as their last field: now we track the length of the array after ``ffi.new()`` is called, just like we always tracked the length of ``ffi.new("int[]", 42)``. This lets us detect out-of-range accesses to array items. This also lets us display a better ``repr()``, and have the total size returned by ``ffi.sizeof()`` and ``ffi.buffer()``. Previously both functions would return a result based on the size of the declared structure type, with an assumed empty array. (Thanks andrew for starting this refactoring.) * Add support in ``cdef()/set_source()`` for unspecified-length arrays in typedefs: ``typedef int foo_t[...];``. It was already supported for global variables or structure fields. * I turned in v1.8 a warning from ``cffi/model.py`` into an error: ``'enum xxx' has no values explicitly defined: refusing to guess which integer type it is meant to be (unsigned/signed, int/long)``. Now I'm turning it back to a warning again; it seems that guessing that the enum has size ``int`` is a 99%-safe bet. (But not 100%, so it stays as a warning.) * Fix leaks in the code handling ``FILE *`` arguments. In CPython 3 there is a remaining issue that is hard to fix: if you pass a Python file object to a ``FILE *`` argument, then ``os.dup()`` is used and the new file descriptor is only closed when the GC reclaims the Python file object---and not at the earlier time when you call ``close()``, which only closes the original file descriptor. If this is an issue, you should avoid this automatic convertion of Python file objects: instead, explicitly manipulate file descriptors and call ``fdopen()`` from C (...via cffi). v1.8.3 ------ * When passing a ``void *`` argument to a function with a different pointer type, or vice-versa, the cast occurs automatically, like in C. The same occurs for initialization with ``ffi.new()`` and a few other places. However, I thought that ``char *`` had the same property---but I was mistaken. In C you get the usual warning if you try to give a ``char *`` to a ``char **`` argument, for example. Sorry about the confusion. This has been fixed in CFFI by giving for now a warning, too. It will turn into an error in a future version. v1.8.2 ------ * Issue #283: fixed ``ffi.new()`` on structures/unions with nested anonymous structures/unions, when there is at least one union in the mix. When initialized with a list or a dict, it should now behave more closely like the ``{ }`` syntax does in GCC. v1.8.1 ------ * CPython 3.x: experimental: the generated C extension modules now use the "limited API", which means that, as a compiled .so/.dll, it should work directly on any version of CPython >= 3.2. The name produced by distutils is still version-specific. To get the version-independent name, you can rename it manually to ``NAME.abi3.so``, or use the very recent setuptools 26. * Added ``ffi.compile(debug=...)``, similar to ``python setup.py build --debug`` but defaulting to True if we are running a debugging version of Python itself. v1.8 ---- * Removed the restriction that ``ffi.from_buffer()`` cannot be used on byte strings. Now you can get a ``char *`` out of a byte string, which is valid as long as the string object is kept alive. (But don't use it to *modify* the string object! If you need this, use ``bytearray`` or other official techniques.) * PyPy 5.4 can now pass a byte string directly to a ``char *`` argument (in older versions, a copy would be made). This used to be a CPython-only optimization. v1.7 ---- * ``ffi.gc(p, None)`` removes the destructor on an object previously created by another call to ``ffi.gc()`` * ``bool(ffi.cast("primitive type", x))`` now returns False if the value is zero (including ``-0.0``), and True otherwise. Previously this would only return False for cdata objects of a pointer type when the pointer is NULL. * bytearrays: ``ffi.from_buffer(bytearray-object)`` is now supported. (The reason it was not supported was that it was hard to do in PyPy, but it works since PyPy 5.3.) To call a C function with a ``char *`` argument from a buffer object---now including bytearrays---you write ``lib.foo(ffi.from_buffer(x))``. Additionally, this is now supported: ``p[0:length] = bytearray-object``. The problem with this was that a iterating over bytearrays gives *numbers* instead of *characters*. (Now it is implemented with just a memcpy, of course, not actually iterating over the characters.) * C++: compiling the generated C code with C++ was supposed to work, but failed if you make use the ``bool`` type (because that is rendered as the C ``_Bool`` type, which doesn't exist in C++). * ``help(lib)`` and ``help(lib.myfunc)`` now give useful information, as well as ``dir(p)`` where ``p`` is a struct or pointer-to-struct. v1.6 ---- * `ffi.list_types()`_ * `ffi.unpack()`_ * `extern "Python+C"`_ * in API mode, ``lib.foo.__doc__`` contains the C signature now. On CPython you can say ``help(lib.foo)``, but for some reason ``help(lib)`` (or ``help(lib.foo)`` on PyPy) is still useless; I haven't yet figured out the hacks needed to convince ``pydoc`` to show more. (You can use ``dir(lib)`` but it is not most helpful.) * Yet another attempt at robustness of ``ffi.def_extern()`` against CPython's interpreter shutdown logic. .. _`ffi.list_types()`: ref.html#ffi-list-types .. _`ffi.unpack()`: ref.html#ffi-unpack .. _`extern "Python+C"`: using.html#extern-python-c v1.5.2 ------ * Fix 1.5.1 for Python 2.6. v1.5.1 ------ * A few installation-time tweaks (thanks Stefano!) * Issue #245: Win32: ``__stdcall`` was never generated for ``extern "Python"`` functions * Issue #246: trying to be more robust against CPython's fragile interpreter shutdown logic v1.5.0 ------ * Support for `using CFFI for embedding`__. .. __: embedding.html v1.4.2 ------ Nothing changed from v1.4.1. v1.4.1 ------ * Fix the compilation failure of cffi on CPython 3.5.0. (3.5.1 works; some detail changed that makes some underscore-starting macros disappear from view of extension modules, and I worked around it, thinking it changed in all 3.5 versions---but no: it was only in 3.5.1.) v1.4.0 ------ * A `better way to do callbacks`__ has been added (faster and more portable, and usually cleaner). It is a mechanism for the out-of-line API mode that replaces the dynamic creation of callback objects (i.e. C functions that invoke Python) with the static declaration in ``cdef()`` of which callbacks are needed. This is more C-like, in that you have to structure your code around the idea that you get a fixed number of function pointers, instead of creating them on-the-fly. * ``ffi.compile()`` now takes an optional ``verbose`` argument. When ``True``, distutils prints the calls to the compiler. * ``ffi.compile()`` used to fail if given ``sources`` with a path that includes ``".."``. Fixed. * ``ffi.init_once()`` added. See docs__. * ``dir(lib)`` now works on libs returned by ``ffi.dlopen()`` too. * Cleaned up and modernized the content of the ``demo`` subdirectory in the sources (thanks matti!). * ``ffi.new_handle()`` is now guaranteed to return unique ``void *`` values, even if called twice on the same object. Previously, in that case, CPython would return two ``cdata`` objects with the same ``void *`` value. This change is useful to add and remove handles from a global dict (or set) without worrying about duplicates. It already used to work like that on PyPy. *This change can break code that used to work on CPython by relying on the object to be kept alive by other means than keeping the result of ffi.new_handle() alive.* (The corresponding `warning in the docs`__ of ``ffi.new_handle()`` has been here since v0.8!) .. __: using.html#extern-python .. __: ref.html#ffi-init-once .. __: ref.html#ffi-new-handle v1.3.1 ------ * The optional typedefs (``bool``, ``FILE`` and all Windows types) were not always available from out-of-line FFI objects. * Opaque enums are phased out from the cdefs: they now give a warning, instead of (possibly wrongly) being assumed equal to ``unsigned int``. Please report if you get a reasonable use case for them. * Some parsing details, notably ``volatile`` is passed along like ``const`` and ``restrict``. Also, older versions of pycparser mis-parse some pointer-to-pointer types like ``char * const *``: the "const" ends up at the wrong place. Added a workaround. v1.3.0 ------ * Added `ffi.memmove()`_. * Pull request #64: out-of-line API mode: we can now declare floating-point types with ``typedef float... foo_t;``. This only works if ``foo_t`` is a float or a double, not ``long double``. * Issue #217: fix possible unaligned pointer manipulation, which crashes on some architectures (64-bit, non-x86). * Issues #64 and #126: when using ``set_source()`` or ``verify()``, the ``const`` and ``restrict`` keywords are copied from the cdef to the generated C code; this fixes warnings by the C compiler. It also fixes corner cases like ``typedef const int T; T a;`` which would previously not consider ``a`` as a constant. (The cdata objects themselves are never ``const``.) * Win32: support for ``__stdcall``. For callbacks and function pointers; regular C functions still don't need to have their `calling convention`_ declared. * Windows: CPython 2.7 distutils doesn't work with Microsoft's official Visual Studio for Python, and I'm told this is `not a bug`__. For ffi.compile(), we `removed a workaround`__ that was inside cffi but which had unwanted side-effects. Try saying ``import setuptools`` first, which patches distutils... .. _`ffi.memmove()`: ref.html#ffi-memmove .. __: https://bugs.python.org/issue23246 .. __: https://bitbucket.org/cffi/cffi/pull-requests/65/remove-_hack_at_distutils-which-imports/diff .. _`calling convention`: using.html#windows-calling-conventions v1.2.1 ------ Nothing changed from v1.2.0. v1.2.0 ------ * Out-of-line mode: ``int a[][...];`` can be used to declare a structure field or global variable which is, simultaneously, of total length unknown to the C compiler (the ``a[]`` part) and each element is itself an array of N integers, where the value of N *is* known to the C compiler (the ``int`` and ``[...]`` parts around it). Similarly, ``int a[5][...];`` is supported (but probably less useful: remember that in C it means ``int (a[5])[...];``). * PyPy: the ``lib.some_function`` objects were missing the attributes ``__name__``, ``__module__`` and ``__doc__`` that are expected e.g. by some decorators-management functions from ``functools``. * Out-of-line API mode: you can now do ``from _example.lib import x`` to import the name ``x`` from ``_example.lib``, even though the ``lib`` object is not a standard module object. (Also works in ``from _example.lib import *``, but this is even more of a hack and will fail if ``lib`` happens to declare a name called ``__all__``. Note that ``*`` excludes the global variables; only the functions and constants make sense to import like this.) * ``lib.__dict__`` works again and gives you a copy of the dict---assuming that ``lib`` has got no symbol called precisely ``__dict__``. (In general, it is safer to use ``dir(lib)``.) * Out-of-line API mode: global variables are now fetched on demand at every access. It fixes issue #212 (Windows DLL variables), and also allows variables that are defined as dynamic macros (like ``errno``) or ``__thread`` -local variables. (This change might also tighten the C compiler's check on the variables' type.) * Issue #209: dereferencing NULL pointers now raises RuntimeError instead of segfaulting. Meant as a debugging aid. The check is only for NULL: if you dereference random or dead pointers you might still get segfaults. * Issue #152: callbacks__: added an argument ``ffi.callback(..., onerror=...)``. If the main callback function raises an exception and ``onerror`` is provided, then ``onerror(exception, exc_value, traceback)`` is called. This is similar to writing a ``try: except:`` in the main callback function, but in some cases (e.g. a signal) an exception can occur at the very start of the callback function---before it had time to enter the ``try: except:`` block. * Issue #115: added ``ffi.new_allocator()``, which officializes support for `alternative allocators`__. .. __: using.html#callbacks .. __: ref.html#ffi-new-allocator v1.1.2 ------ * ``ffi.gc()``: fixed a race condition in multithreaded programs introduced in 1.1.1 v1.1.1 ------ * Out-of-line mode: ``ffi.string()``, ``ffi.buffer()`` and ``ffi.getwinerror()`` didn't accept their arguments as keyword arguments, unlike their in-line mode equivalent. (It worked in PyPy.) * Out-of-line ABI mode: documented a restriction__ of ``ffi.dlopen()`` when compared to the in-line mode. * ``ffi.gc()``: when called several times with equal pointers, it was accidentally registering only the last destructor, or even none at all depending on details. (It was correctly registering all of them only in PyPy, and only with the out-of-line FFIs.) .. __: cdef.html#dlopen-note v1.1.0 ------ * Out-of-line API mode: we can now declare integer types with ``typedef int... foo_t;``. The exact size and signedness of ``foo_t`` is figured out by the compiler. * Out-of-line API mode: we can now declare multidimensional arrays (as fields or as globals) with ``int n[...][...]``. Before, only the outermost dimension would support the ``...`` syntax. * Out-of-line ABI mode: we now support any constant declaration, instead of only integers whose value is given in the cdef. Such "new" constants, i.e. either non-integers or without a value given in the cdef, must correspond to actual symbols in the lib. At runtime they are looked up the first time we access them. This is useful if the library defines ``extern const sometype somename;``. * ``ffi.addressof(lib, "func_name")`` now returns a regular cdata object of type "pointer to function". You can use it on any function from a library in API mode (in ABI mode, all functions are already regular cdata objects). To support this, you need to recompile your cffi modules. * Issue #198: in API mode, if you declare constants of a ``struct`` type, what you saw from lib.CONSTANT was corrupted. * Issue #196: ``ffi.set_source("package._ffi", None)`` would incorrectly generate the Python source to ``package._ffi.py`` instead of ``package/_ffi.py``. Also fixed: in some cases, if the C file was in ``build/foo.c``, the .o file would be put in ``build/build/foo.o``. v1.0.3 ------ * Same as 1.0.2, apart from doc and test fixes on some platforms. v1.0.2 ------ * Variadic C functions (ending in a "..." argument) were not supported in the out-of-line ABI mode. This was a bug---there was even a (non-working) example__ doing exactly that! .. __: overview.html#out-of-line-abi-level v1.0.1 ------ * ``ffi.set_source()`` crashed if passed a ``sources=[..]`` argument. Fixed by chrippa on pull request #60. * Issue #193: if we use a struct between the first cdef() where it is declared and another cdef() where its fields are defined, then this definition was ignored. * Enums were buggy if you used too many "..." in their definition. v1.0.0 ------ * The main news item is out-of-line module generation: * `for ABI level`_, with ``ffi.dlopen()`` * `for API level`_, which used to be with ``ffi.verify()``, now deprecated * (this page will list what is new from all versions from 1.0.0 forward.) .. _`for ABI level`: overview.html#out-of-line-abi-level .. _`for API level`: overview.html#out-of-line-api-level