Backported PyCapsule from 3.1, and converted most uses of

CObject to PyCapsule.

15 files changed, 240 insertions, 46 deletions

diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index cf17e3a..8e0b6a0 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -83,6 +83,13 @@
 #define DONT_USE_SEH
 #endif
 
+
+#define CTYPES_CAPSULE_ERROROBJ "_ctypes/callproc.c error object"
+CTYPES_CAPSULE_INSTANTIATE_DESTRUCTOR(CTYPES_CAPSULE_ERROROBJ)
+
+#define CTYPES_CAPSULE_WCHAR_T "_ctypes/callproc.c wchar_t buffer from unicode"
+CTYPES_CAPSULE_INSTANTIATE_DESTRUCTOR(CTYPES_CAPSULE_WCHAR_T)
+
 /*
   ctypes maintains thread-local storage that has space for two error numbers:
   private copies of the system 'errno' value and, on Windows, the system error code
@@ -134,14 +141,22 @@ _ctypes_get_errobj(int **pspace)
 			return NULL;
 	}
 	errobj = PyDict_GetItem(dict, error_object_name);
-	if (errobj)
+	if (errobj) {
+#ifdef CTYPES_USING_CAPSULE
+		if (!PyCapsule_IsValid(errobj, CTYPES_CAPSULE_ERROROBJ)) {
+			PyErr_SetString(PyExc_RuntimeError,
+				"ctypes.error_object is an invalid capsule");
+			return NULL;
+		}
+#endif /* CTYPES_USING_CAPSULE */
 		Py_INCREF(errobj);
+	}
 	else {
 		void *space = PyMem_Malloc(sizeof(int) * 2);
 		if (space == NULL)
 			return NULL;
 		memset(space, 0, sizeof(int) * 2);
-		errobj = PyCObject_FromVoidPtr(space, PyMem_Free);
+		errobj = CAPSULE_NEW(space, CTYPES_CAPSULE_ERROROBJ);
 		if (errobj == NULL)
 			return NULL;
 		if (-1 == PyDict_SetItem(dict, error_object_name,
@@ -150,7 +165,7 @@ _ctypes_get_errobj(int **pspace)
 			return NULL;
 		}
 	}
-	*pspace = (int *)PyCObject_AsVoidPtr(errobj);
+	*pspace = (int *)CAPSULE_DEREFERENCE(errobj, CTYPES_CAPSULE_ERROROBJ);
 	return errobj;
 }
 
@@ -670,7 +685,7 @@ static int ConvParam(PyObject *obj, Py_ssize_t index, struct argument *pa)
 			return -1;
 		}
 		memset(pa->value.p, 0, size);
-		pa->keep = PyCObject_FromVoidPtr(pa->value.p, PyMem_Free);
+		pa->keep = CAPSULE_NEW(pa->value.p, CTYPES_CAPSULE_WCHAR_T);
 		if (!pa->keep) {
 			PyMem_Free(pa->value.p);
 			return -1;
diff --git a/Modules/_ctypes/cfield.c b/Modules/_ctypes/cfield.c
index bf247bc..d7fc5d2 100644
--- a/Modules/_ctypes/cfield.c
+++ b/Modules/_ctypes/cfield.c
@@ -10,6 +10,11 @@
 #endif
 #include "ctypes.h"
 
+
+#define CTYPES_CAPSULE_WCHAR_T "_ctypes/cfield.c wchar_t buffer from unicode"
+CTYPES_CAPSULE_INSTANTIATE_DESTRUCTOR(CTYPES_CAPSULE_WCHAR_T)
+
+
 /******************************************************************/
 /*
   PyCField_Type
@@ -1457,7 +1462,7 @@ Z_set(void *ptr, PyObject *value, Py_ssize_t size)
 			return PyErr_NoMemory();
 		}
 		memset(buffer, 0, size);
-		keep = PyCObject_FromVoidPtr(buffer, PyMem_Free);
+		keep = CAPSULE_NEW(buffer, CTYPES_CAPSULE_WCHAR_T);
 		if (!keep) {
 			Py_DECREF(value);
 			PyMem_Free(buffer);
diff --git a/Modules/_ctypes/ctypes.h b/Modules/_ctypes/ctypes.h
index 1003614..718ee52 100644
--- a/Modules/_ctypes/ctypes.h
+++ b/Modules/_ctypes/ctypes.h
@@ -445,6 +445,40 @@ PyObject *_ctypes_get_errobj(int **pspace);
 extern PyObject *ComError;
 #endif
 
+#if PY_VERSION_HEX >= 0x020700A4
+/* Use PyCapsule for 2.7 */
+
+#define CTYPES_USING_CAPSULE
+
+#define CTYPES_CAPSULE_INSTANTIATE_DESTRUCTOR(name) \
+static void capsule_destructor_ ## name(PyObject *ptr) \
+{ \
+	void *p = PyCapsule_GetPointer(ptr, name); \
+	if (p) { \
+		PyMem_Free(p); \
+	} \
+} \
+
+#define CAPSULE_NEW(pointer, name) \
+	(PyCapsule_New(pointer, name, capsule_destructor_ ## name))
+
+#define CAPSULE_DEREFERENCE(capsule, name) \
+  (PyCapsule_GetPointer(capsule, name))
+
+#else /* PY_VERSION_HEX >= 0x020700A4 */
+/* Use CObject for 2.6 and before */
+
+#define CTYPES_CAPSULE_INSTANTIATE_DESTRUCTOR(name)
+
+#define CAPSULE_NEW(pointer, name) \
+	(PyCObject_FromVoidPtr(pointer, PyMem_Free))
+
+#define CAPSULE_DEREFERENCE(capsule, name) \
+  (PyCObject_AsVoidPtr(capsule))
+
+#endif /* PY_VERSION_HEX >= 0x020700A4 */
+
+
 /*
  Local Variables:
  compile-command: "python setup.py -q build install --home ~"
diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
index 430ab17..3f95cef 100644
--- a/Modules/_cursesmodule.c
+++ b/Modules/_cursesmodule.c
@@ -172,7 +172,7 @@ static int initialisedcolors = FALSE;
 /*
  * Check the return code from a curses function and return None 
  * or raise an exception as appropriate.  These are exported using the
- * CObject API. 
+ * capsule API.
  */
 
 static PyObject *
@@ -2745,8 +2745,8 @@ init_curses(void)
 		return;
 	ModDict = d; /* For PyCurses_InitScr to use later */
 
-	/* Add a CObject for the C API */
-	c_api_object = PyCObject_FromVoidPtr((void *)PyCurses_API, NULL);
+	/* Add a capsule for the C API */
+	c_api_object = PyCapsule_New(PyCurses_API, PyCurses_CAPSULE_NAME, NULL);
 	PyDict_SetItemString(d, "_C_API", c_api_object);
 	Py_DECREF(c_api_object);
 
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index 0aa1ebb..4311ba2 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -3059,7 +3059,7 @@ init_elementtree(void)
 
 #if defined(USE_PYEXPAT_CAPI)
     /* link against pyexpat, if possible */
-    expat_capi = PyCObject_Import("pyexpat", "expat_CAPI");
+    expat_capi = PyCapsule_Import(PyExpat_CAPSULE_NAME, 0);
     if (expat_capi) {
         /* check that it's usable */
         if (strcmp(expat_capi->magic, PyExpat_CAPI_MAGIC) != 0 ||
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 6bc6da2..023e62e 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -1428,6 +1428,157 @@ test_string_from_format(PyObject *self, PyObject *args)
 #undef CHECK_1_FORMAT
 }
 
+/* Coverage testing of capsule objects. */
+
+static const char *capsule_name = "capsule name";
+static       char *capsule_pointer = "capsule pointer";
+static       char *capsule_context = "capsule context";
+static const char *capsule_error = NULL;
+static int
+capsule_destructor_call_count = 0;
+
+static void
+capsule_destructor(PyObject *o) {
+	capsule_destructor_call_count++;
+	if (PyCapsule_GetContext(o) != capsule_context) {
+		capsule_error = "context did not match in destructor!";
+	} else if (PyCapsule_GetDestructor(o) != capsule_destructor) {
+		capsule_error = "destructor did not match in destructor!  (woah!)";
+	} else if (PyCapsule_GetName(o) != capsule_name) {
+		capsule_error = "name did not match in destructor!";
+	} else if (PyCapsule_GetPointer(o, capsule_name) != capsule_pointer) {
+		capsule_error = "pointer did not match in destructor!";
+	}
+}
+
+typedef struct {
+	char *name;
+	char *module;
+	char *attribute;
+} known_capsule;
+
+static PyObject *
+test_capsule(PyObject *self, PyObject *args)
+{
+	PyObject *object;
+	const char *error = NULL;
+	void *pointer;
+	void *pointer2;
+	known_capsule known_capsules[] = {
+		#define KNOWN_CAPSULE(module, name)	{ module "." name, module, name }
+		KNOWN_CAPSULE("_socket", "CAPI"),
+		KNOWN_CAPSULE("_curses", "_C_API"),
+		KNOWN_CAPSULE("datetime", "datetime_CAPI"),
+		{ NULL, NULL },
+	};
+	known_capsule *known = &known_capsules[0];
+
+#define FAIL(x) { error = (x); goto exit; }
+
+#define CHECK_DESTRUCTOR \
+	if (capsule_error) { \
+		FAIL(capsule_error); \
+	} \
+	else if (!capsule_destructor_call_count) {	\
+		FAIL("destructor not called!"); \
+	} \
+	capsule_destructor_call_count = 0; \
+
+	object = PyCapsule_New(capsule_pointer, capsule_name, capsule_destructor);
+	PyCapsule_SetContext(object, capsule_context);
+	capsule_destructor(object);
+	CHECK_DESTRUCTOR;
+	Py_DECREF(object);
+	CHECK_DESTRUCTOR;
+
+	object = PyCapsule_New(known, "ignored", NULL);
+	PyCapsule_SetPointer(object, capsule_pointer);
+	PyCapsule_SetName(object, capsule_name);
+	PyCapsule_SetDestructor(object, capsule_destructor);
+	PyCapsule_SetContext(object, capsule_context);
+	capsule_destructor(object);
+	CHECK_DESTRUCTOR;
+	/* intentionally access using the wrong name */
+	pointer2 = PyCapsule_GetPointer(object, "the wrong name");
+	if (!PyErr_Occurred()) {
+		FAIL("PyCapsule_GetPointer should have failed but did not!");
+	}
+	PyErr_Clear();
+	if (pointer2) {
+		if (pointer2 == capsule_pointer) {
+			FAIL("PyCapsule_GetPointer should not have"
+				 " returned the internal pointer!");
+		} else {
+			FAIL("PyCapsule_GetPointer should have "
+				 "returned NULL pointer but did not!");
+		}
+	}
+	PyCapsule_SetDestructor(object, NULL);
+	Py_DECREF(object);
+	if (capsule_destructor_call_count) {
+		FAIL("destructor called when it should not have been!");
+	}
+
+	for (known = &known_capsules[0]; known->module != NULL; known++) {
+		/* yeah, ordinarily I wouldn't do this either,
+		   but it's fine for this test harness.
+		*/
+		static char buffer[256];
+#undef FAIL
+#define FAIL(x) \
+		{ \
+		sprintf(buffer, "%s module: \"%s\" attribute: \"%s\"", \
+			x, known->module, known->attribute); \
+		error = buffer; \
+		goto exit; \
+		} \
+
+		PyObject *module = PyImport_ImportModule(known->module);
+		if (module) {
+			pointer = PyCapsule_Import(known->name, 0);
+			if (!pointer) {
+				Py_DECREF(module);
+				FAIL("PyCapsule_GetPointer returned NULL unexpectedly!");
+			}
+			object = PyObject_GetAttrString(module, known->attribute);
+			if (!object) {
+				Py_DECREF(module);
+				return NULL;
+			}
+			pointer2 = PyCapsule_GetPointer(object,
+						"weebles wobble but they don't fall down");
+			if (!PyErr_Occurred()) {
+				Py_DECREF(object);
+				Py_DECREF(module);
+				FAIL("PyCapsule_GetPointer should have failed but did not!");
+			}
+			PyErr_Clear();
+			if (pointer2) {
+				Py_DECREF(module);
+				Py_DECREF(object);
+				if (pointer2 == pointer) {
+					FAIL("PyCapsule_GetPointer should not have"
+						 " returned its internal pointer!");
+				} else {
+					FAIL("PyCapsule_GetPointer should have"
+						 " returned NULL pointer but did not!");
+				}
+			}
+			Py_DECREF(object);
+			Py_DECREF(module);
+		}
+		else
+			PyErr_Clear();
+	}
+
+  exit:
+	if (error) {
+		return raiseTestError("test_capsule", error);
+	}
+	Py_RETURN_NONE;
+#undef FAIL
+}
+
 /* This is here to provide a docstring for test_descr. */
 static PyObject *
 test_with_docstring(PyObject *self)
@@ -1539,6 +1690,7 @@ static PyMethodDef TestMethods[] = {
 	{"_test_thread_state",  test_thread_state, 		 METH_VARARGS},
 	{"_pending_threadfunc",	pending_threadfunc,		 METH_VARARGS},
 #endif
+	{"test_capsule", (PyCFunction)test_capsule, METH_NOARGS},
 	{"traceback_print", traceback_print, 	         METH_VARARGS},
 	{"code_newempty", code_newempty, 	         METH_VARARGS},
 	{"make_exception_with_doc", (PyCFunction)make_exception_with_doc,
diff --git a/Modules/cStringIO.c b/Modules/cStringIO.c
index 237d8c2..80588bf 100644
--- a/Modules/cStringIO.c
+++ b/Modules/cStringIO.c
@@ -761,8 +761,8 @@ initcStringIO(void) {
   Py_TYPE(&Otype)=&PyType_Type;
   if (PyType_Ready(&Otype) < 0) return;
   if (PyType_Ready(&Itype) < 0) return;
-  PyDict_SetItemString(d,"cStringIO_CAPI",
-		       v = PyCObject_FromVoidPtr(&CAPI,NULL));
+  v = PyCapsule_New(&CAPI, PycStringIO_CAPSULE_NAME, NULL);
+  PyDict_SetItemString(d,"cStringIO_CAPI", v);
   Py_XDECREF(v);
 
   /* Export Types */
diff --git a/Modules/cjkcodecs/cjkcodecs.h b/Modules/cjkcodecs/cjkcodecs.h
index 4005bcf..236c3fe 100644
--- a/Modules/cjkcodecs/cjkcodecs.h
+++ b/Modules/cjkcodecs/cjkcodecs.h
@@ -282,7 +282,7 @@ getcodec(PyObject *self, PyObject *encoding)
 		return NULL;
 	}
 
-	codecobj = PyCObject_FromVoidPtr((void *)codec, NULL);
+	codecobj = PyCapsule_New((void *)codec, PyMultibyteCodec_CAPSULE_NAME, NULL);
 	if (codecobj == NULL)
 		return NULL;
 
@@ -307,7 +307,7 @@ register_maps(PyObject *module)
 		int r;
 		strcpy(mhname + sizeof("__map_") - 1, h->charset);
 		r = PyModule_AddObject(module, mhname,
-				PyCObject_FromVoidPtr((void *)h, NULL));
+				PyCapsule_New((void *)h, PyMultibyteCodec_CAPSULE_NAME, NULL));
 		if (r == -1)
 			return -1;
 	}
@@ -362,14 +362,14 @@ importmap(const char *modname, const char *symbol,
 	o = PyObject_GetAttrString(mod, (char*)symbol);
 	if (o == NULL)
 		goto errorexit;
-	else if (!PyCObject_Check(o)) {
+	else if (!PyCapsule_IsValid(o, PyMultibyteCodec_CAPSULE_NAME)) {
 		PyErr_SetString(PyExc_ValueError,
-				"map data must be a CObject.");
+				"map data must be a Capsule.");
 		goto errorexit;
 	}
 	else {
 		struct dbcs_map *map;
-		map = PyCObject_AsVoidPtr(o);
+		map = PyCapsule_GetPointer(o, PyMultibyteCodec_CAPSULE_NAME);
 		if (encmap != NULL)
 			*encmap = map->encmap;
 		if (decmap != NULL)
diff --git a/Modules/cjkcodecs/multibytecodec.c b/Modules/cjkcodecs/multibytecodec.c
index 5fb5ec0..794774b 100644
--- a/Modules/cjkcodecs/multibytecodec.c
+++ b/Modules/cjkcodecs/multibytecodec.c
@@ -1774,12 +1774,12 @@ __create_codec(PyObject *ignore, PyObject *arg)
 	MultibyteCodecObject *self;
 	MultibyteCodec *codec;
 
-	if (!PyCObject_Check(arg)) {
+	if (!PyCapsule_IsValid(arg, PyMultibyteCodec_CAPSULE_NAME)) {
 		PyErr_SetString(PyExc_ValueError, "argument type invalid");
 		return NULL;
 	}
 
-	codec = PyCObject_AsVoidPtr(arg);
+	codec = PyCapsule_GetPointer(arg, PyMultibyteCodec_CAPSULE_NAME);
 	if (codec->codecinit != NULL && codec->codecinit(codec->config) != 0)
 		return NULL;
 
diff --git a/Modules/cjkcodecs/multibytecodec.h b/Modules/cjkcodecs/multibytecodec.h
index 22ea5d4..71c02cc 100644
--- a/Modules/cjkcodecs/multibytecodec.h
+++ b/Modules/cjkcodecs/multibytecodec.h
@@ -132,6 +132,9 @@ typedef struct {
 #define MBENC_FLUSH		0x0001 /* encode all characters encodable */
 #define MBENC_MAX		MBENC_FLUSH
 
+#define PyMultibyteCodec_CAPSULE_NAME "multibytecodec.__map_*"
+
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Modules/datetimemodule.c b/Modules/datetimemodule.c
index 7b9e271..3f1eb57 100644
--- a/Modules/datetimemodule.c
+++ b/Modules/datetimemodule.c
@@ -4856,11 +4856,10 @@ initdatetime(void)
 	Py_INCREF(&PyDateTime_TZInfoType);
 	PyModule_AddObject(m, "tzinfo", (PyObject *) &PyDateTime_TZInfoType);
 
-        x = PyCObject_FromVoidPtrAndDesc(&CAPI, (void*) DATETIME_API_MAGIC,
-                NULL);
-        if (x == NULL)
-            return;
-        PyModule_AddObject(m, "datetime_CAPI", x);
+	x = PyCapsule_New(&CAPI, PyDateTime_CAPSULE_NAME, NULL);
+	if (x == NULL)
+		return NULL;
+	PyModule_AddObject(m, "datetime_CAPI", x);
 
 	/* A 4-year cycle has an extra leap day over what we'd get from
 	 * pasting together 4 single years.
diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index 47ef186..d428c66 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -2053,8 +2053,8 @@ MODULE_INITFUNC(void)
     capi.SetUnknownEncodingHandler = XML_SetUnknownEncodingHandler;
     capi.SetUserData = XML_SetUserData;
     
-    /* export as cobject */
-    capi_object = PyCObject_FromVoidPtr(&capi, NULL);
+    /* export using capsule */
+    capi_object = PyCapsule_New(&capi, PyExpat_CAPSULE_NAME, NULL);
     if (capi_object)
         PyModule_AddObject(m, "expat_CAPI", capi_object);
 }
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index fbd0239..d44a691 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -4496,7 +4496,7 @@ init_socket(void)
 
 	/* Export C API */
 	if (PyModule_AddObject(m, PySocket_CAPI_NAME,
-	       PyCObject_FromVoidPtr((void *)&PySocketModuleAPI, NULL)
+	       PyCapsule_New(&PySocketModuleAPI, PySocket_CAPSULE_NAME, NULL)
 				 ) != 0)
 		return;
 
diff --git a/Modules/socketmodule.h b/Modules/socketmodule.h
index ef8d0fc..48f230e 100644
--- a/Modules/socketmodule.h
+++ b/Modules/socketmodule.h
@@ -78,6 +78,7 @@ extern "C" {
 /* Python module and C API name */
 #define PySocket_MODULE_NAME	"_socket"
 #define PySocket_CAPI_NAME	"CAPI"
+#define PySocket_CAPSULE_NAME  (PySocket_MODULE_NAME "." PySocket_CAPI_NAME)
 
 /* Abstract the socket file descriptor type */
 #ifdef MS_WINDOWS
@@ -142,12 +143,12 @@ typedef struct {
     the _socket module. Since cross-DLL linking introduces a lot of
     problems on many platforms, the "trick" is to wrap the
     C API of a module in a struct which then gets exported to
-    other modules via a PyCObject.
+    other modules via a PyCapsule.
 
     The code in socketmodule.c defines this struct (which currently
     only contains the type object reference, but could very
     well also include other C APIs needed by other modules)
-    and exports it as PyCObject via the module dictionary
+    and exports it as PyCapsule via the module dictionary
     under the name "CAPI".
 
     Other modules can now include the socketmodule.h file
@@ -226,33 +227,18 @@ PySocketModule_APIObject PySocketModule;
 static
 int PySocketModule_ImportModuleAndAPI(void)
 {
-	PyObject *mod = 0, *v = 0;
-	char *apimodule = PySocket_MODULE_NAME;
-	char *apiname = PySocket_CAPI_NAME;
 	void *api;
 
-	DPRINTF("Importing the %s C API...\n", apimodule);
-	mod = PyImport_ImportModuleNoBlock(apimodule);
-	if (mod == NULL)
-		goto onError;
-	DPRINTF(" %s package found\n", apimodule);
-	v = PyObject_GetAttrString(mod, apiname);
-	if (v == NULL)
-		goto onError;
-	Py_DECREF(mod);
-	DPRINTF(" API object %s found\n", apiname);
-	api = PyCObject_AsVoidPtr(v);
+  DPRINTF(" Loading capsule %s\n", PySocket_CAPSULE_NAME);
+  api = PyCapsule_Import(PySocket_CAPSULE_NAME, 1);
 	if (api == NULL)
 		goto onError;
-	Py_DECREF(v);
 	memcpy(&PySocketModule, api, sizeof(PySocketModule));
 	DPRINTF(" API object loaded and initialized.\n");
 	return 0;
 
  onError:
 	DPRINTF(" not found.\n");
-	Py_XDECREF(mod);
-	Py_XDECREF(v);
 	return -1;
 }
 
diff --git a/Modules/unicodedata.c b/Modules/unicodedata.c
index 552dae5..ede57cb 100644
--- a/Modules/unicodedata.c
+++ b/Modules/unicodedata.c
@@ -1261,7 +1261,7 @@ initunicodedata(void)
         PyModule_AddObject(m, "ucd_3_2_0", v);
 
     /* Export C API */
-    v = PyCObject_FromVoidPtr((void *) &hashAPI, NULL);
+    v = PyCapsule_New((void *)&hashAPI, PyUnicodeData_CAPSULE_NAME, NULL);
     if (v != NULL)
         PyModule_AddObject(m, "ucnhash_CAPI", v);
 }