[Cython] Proposal: extern implementations of functions
Hello Cython developers,
I would like to propose a new mechanism to implement functions in an
external .c file. The goal is to solve the problem I was having in
https://groups.google.com/forum/#!topic/cython-users/TsbBNyvwZn4
With the attached patch, you can do the following:
* in foo.pxd, declare the function as usual:
cdef void myfunc()
* in foo.c, actually implement the function:
static void myfunc()
{
/* ... */
}
* in foo.pyx, declare the function extern:
cdef extern from "foo.c":
void myfunc()
With my patch, the extern declaration in foo.pyx will be interpreted as
implementing the function. Therefore, myfunc() is now available in the
module foo, and it can also be cimported by other modules.
What do you think of this proposed feature?
Jeroen.
diff --git a/Cython/Compiler/Symtab.py b/Cython/Compiler/Symtab.py
index 339b509..1437f83 100644
--- a/Cython/Compiler/Symtab.py
+++ b/Cython/Compiler/Symtab.py
@@ -698,8 +698,15 @@ class Scope(object):
cname = self.mangle(Naming.func_prefix, name)
entry = self.lookup_here(name)
if entry:
+if not in_pxd and visibility != entry.visibility and visibility == 'extern':
+# Previously declared, but now extern => treat this
+# as implementing the function, using the new cname
+defining = True
+visibility = entry.visibility
+entry.cname = cname
+entry.func_cname = cname
if visibility != 'private' and visibility != entry.visibility:
-warning(pos, "Function '%s' previously declared as '%s'" % (name, entry.visibility), 1)
+warning(pos, "Function '%s' previously declared as '%s', now as '%s'" % (name, entry.visibility, visibility), 1)
if overridable != entry.is_overridable:
warning(pos, "Function '%s' previously declared as '%s'" % (
name, 'cpdef' if overridable else 'cdef'), 1)
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[Cython] Cython magic annotate option is broken under IPython 3.0
Hi all, To reproduce this issue, be on cython 0.22 and IPython 3.0 and run the following notebook: http://nbviewer.ipython.org/gist/ngoldbaum/855a629d997aa7959254 Googling the error returns some several year old discussions in IPython related to the autoreload magic and I'm not sure if that is a red herring here: http://mail.scipy.org/pipermail/ipython-dev/2012-May/009288.html For how I'm working around this by calling cython at the command line in my notebook and then loading the annotated HTML with an IFrame. Thanks for your help! ___ cython-devel mailing list cython-devel@python.org https://mail.python.org/mailman/listinfo/cython-devel
[Cython] Generated function has invalid name when converting from python object to C struct defined in C++ namespace
Hello,
I have Cython code like this:
cdef extern from "cpp_library.h" namespace "CppLibrary":
struct SomeStruct:
int i
void do_with_struct(SomeStruct s)
def run():
do_with_struct(object())
With cython 0.21.1, invalid C++ code is generated:
struct CppLibrary::SomeStruct;
static struct CppLibrary::SomeStruct
__pyx_convert__from_py_CppLibrary::SomeStruct(PyObject *);
With cython master, a compiler error occurs:
@cname("__pyx_convert__from_py_CppLibrary::SomeStruct")
cdef SomeStruct __pyx_convert__from_py_CppLibrary::SomeStruct(obj)
except *:
^
FromPyStructUtility:11:50: Expected an identifier or literal
Cython should mangle the struct name to ensure the helper function has a
valid name.
Regards,
--
Daniel Grunwald
Axivion GmbH
Nobelstr. 15
70569 Stuttgart
Deutschland
Tel: +49 711 6204378-33
Fax: +49 711 6204378-99
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Registergericht: Amtsgericht Stuttgart, HRB 720590
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Re: [Cython] PyPy3 fixes
Lisandro Dalcin schrieb am 08.03.2015 um 20:25: > 1) Stefan, I had to push this fix, just to be sure, please double check. > > https://github.com/cython/cython/commit/6bd3f7b9e494d1259082aecfc0366da15fc105ec Thanks - sorry for the bug. > 2) PyPy3 defines some legacy (Py2) Py_TPFLAGS_XXX values. Do you like > the following fix? IOW, I check if the value is #define'd, if not I > #define it to 0 (zero): > > diff --git a/Cython/Utility/ModuleSetupCode.c > b/Cython/Utility/ModuleSetupCode.c > index 6477fb2..3ae8a0c 100644 > --- a/Cython/Utility/ModuleSetupCode.c > +++ b/Cython/Utility/ModuleSetupCode.c > @@ -59,13 +59,16 @@ >#define __Pyx_DefaultClassType PyType_Type > #endif > > -#if PY_MAJOR_VERSION >= 3 > +#if !defined(Py_TPFLAGS_CHECKTYPES) >#define Py_TPFLAGS_CHECKTYPES 0 > +#endif > +#if !defined(Py_TPFLAGS_HAVE_INDEX) >#define Py_TPFLAGS_HAVE_INDEX 0 > +#endif > +#if !defined(Py_TPFLAGS_HAVE_NEWBUFFER) >#define Py_TPFLAGS_HAVE_NEWBUFFER 0 > #endif > - > -#if PY_VERSION_HEX < 0x030400a1 && !defined(Py_TPFLAGS_HAVE_FINALIZE) > +#if !defined(Py_TPFLAGS_HAVE_FINALIZE) >#define Py_TPFLAGS_HAVE_FINALIZE 0 > #endif LGTM. I tend to use the shorter "#ifndef" instead of "#if !defined()", though. Stefan ___ cython-devel mailing list cython-devel@python.org https://mail.python.org/mailman/listinfo/cython-devel
