Provide __module__ attributes for functions defined in C and Python.

__module__ is the string name of the module the function was defined
in, just like __module__ of classes.  In some cases, particularly for
C functions, the __module__ may be None.

Change PyCFunction_New() from a function to a macro, but keep an
unused copy of the function around so that we don't change the binary
API.

Change pickle's save_global() to use whichmodule() if __module__ is
None, but add the __module__ logic to whichmodule() since it might be
used outside of pickle.

8 files changed, 114 insertions, 18 deletions

diff --git a/Include/funcobject.h b/Include/funcobject.h
index 7fee800..758c76d 100644
--- a/Include/funcobject.h
+++ b/Include/funcobject.h
@@ -17,6 +17,7 @@ typedef struct {
     PyObject *func_name;
     PyObject *func_dict;
     PyObject *func_weakreflist;
+    PyObject *func_module;
 } PyFunctionObject;
 
 PyAPI_DATA(PyTypeObject) PyFunction_Type;
@@ -26,6 +27,7 @@ PyAPI_DATA(PyTypeObject) PyFunction_Type;
 PyAPI_FUNC(PyObject *) PyFunction_New(PyObject *, PyObject *);
 PyAPI_FUNC(PyObject *) PyFunction_GetCode(PyObject *);
 PyAPI_FUNC(PyObject *) PyFunction_GetGlobals(PyObject *);
+PyAPI_FUNC(PyObject *) PyFunction_GetModule(PyObject *);
 PyAPI_FUNC(PyObject *) PyFunction_GetDefaults(PyObject *);
 PyAPI_FUNC(int) PyFunction_SetDefaults(PyObject *, PyObject *);
 PyAPI_FUNC(PyObject *) PyFunction_GetClosure(PyObject *);
@@ -37,6 +39,8 @@ PyAPI_FUNC(int) PyFunction_SetClosure(PyObject *, PyObject *);
         (((PyFunctionObject *)func) -> func_code)
 #define PyFunction_GET_GLOBALS(func) \
 	(((PyFunctionObject *)func) -> func_globals)
+#define PyFunction_GET_MODULE(func) \
+	(((PyFunctionObject *)func) -> func_module)
 #define PyFunction_GET_DEFAULTS(func) \
 	(((PyFunctionObject *)func) -> func_defaults)
 #define PyFunction_GET_CLOSURE(func) \
diff --git a/Include/methodobject.h b/Include/methodobject.h
index 993bdae..887385d 100644
--- a/Include/methodobject.h
+++ b/Include/methodobject.h
@@ -40,7 +40,9 @@ typedef struct PyMethodDef PyMethodDef;
 
 PyAPI_FUNC(PyObject *) Py_FindMethod(PyMethodDef[], PyObject *, char *);
 
-PyAPI_FUNC(PyObject *) PyCFunction_New(PyMethodDef *, PyObject *);
+#define PyCFunction_New(ML, SELF) PyCFunction_NewEx((ML), (SELF), NULL)
+PyAPI_FUNC(PyObject *) PyCFunction_NewEx(PyMethodDef *, PyObject *, 
+					 PyObject *);
 
 /* Flag passed to newmethodobject */
 #define METH_OLDARGS  0x0000
@@ -68,6 +70,7 @@ typedef struct {
     PyObject_HEAD
     PyMethodDef *m_ml;
     PyObject    *m_self;
+    PyObject    *m_module;
 } PyCFunctionObject;
 
 #ifdef __cplusplus
diff --git a/Lib/pickle.py b/Lib/pickle.py
index ec19e24..e365bd1 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -787,9 +787,8 @@ class Pickler:
         if name is None:
             name = obj.__name__
 
-        try:
-            module = obj.__module__
-        except AttributeError:
+        module = getattr(obj, "__module__", None)
+        if module is None:
             module = whichmodule(obj, name)
 
         try:
@@ -876,6 +875,10 @@ def whichmodule(func, funcname):
     Return a module name.
     If the function cannot be found, return "__main__".
     """
+    # Python functions should always get an __module__ from their globals.
+    mod = getattr(func, "__module__", None)
+    if mod is not None:
+        return mod
     if func in classmap:
         return classmap[func]
 
diff --git a/Lib/test/test_funcattrs.py b/Lib/test/test_funcattrs.py
index 3dc888c..2c31d36 100644
--- a/Lib/test/test_funcattrs.py
+++ b/Lib/test/test_funcattrs.py
@@ -9,6 +9,10 @@ def b():
     'my docstring'
     pass
 
+# __module__ is a special attribute
+verify(b.__module__ == __name__)
+verify(verify.__module__ == "test.test_support")
+
 # setting attributes on functions
 try:
     b.publish
diff --git a/Objects/funcobject.c b/Objects/funcobject.c
index 6154d99..b162fdf 100644
--- a/Objects/funcobject.c
+++ b/Objects/funcobject.c
@@ -14,6 +14,7 @@ PyFunction_New(PyObject *code, PyObject *globals)
 	if (op != NULL) {
 		PyObject *doc;
 		PyObject *consts;
+		PyObject *module;
 		op->func_weakreflist = NULL;
 		Py_INCREF(code);
 		op->func_code = code;
@@ -34,6 +35,16 @@ PyFunction_New(PyObject *code, PyObject *globals)
 		Py_INCREF(doc);
 		op->func_doc = doc;
 		op->func_dict = NULL;
+		op->func_module = NULL;
+
+		/* __module__: If module name is in globals, use it.
+		   Otherwise, use None.
+		*/
+		module = PyDict_GetItemString(globals, "__name__");
+		if (module) {
+		    Py_INCREF(module);
+		    op->func_module = module;
+		}
 	}
 	else
 		return NULL;
@@ -62,6 +73,16 @@ PyFunction_GetGlobals(PyObject *op)
 }
 
 PyObject *
+PyFunction_GetModule(PyObject *op)
+{
+	if (!PyFunction_Check(op)) {
+		PyErr_BadInternalCall();
+		return NULL;
+	}
+	return ((PyFunctionObject *) op) -> func_module;
+}
+
+PyObject *
 PyFunction_GetDefaults(PyObject *op)
 {
 	if (!PyFunction_Check(op)) {
@@ -138,6 +159,7 @@ static PyMemberDef func_memberlist[] = {
 	 RESTRICTED|READONLY},
         {"func_name",     T_OBJECT,     OFF(func_name),         READONLY},
         {"__name__",      T_OBJECT,     OFF(func_name),         READONLY},
+	{"__module__",    T_OBJECT,     OFF(func_module),       READONLY},
         {NULL}  /* Sentinel */
 };
 
@@ -373,6 +395,7 @@ func_dealloc(PyFunctionObject *op)
 		PyObject_ClearWeakRefs((PyObject *) op);
 	Py_DECREF(op->func_code);
 	Py_DECREF(op->func_globals);
+	Py_XDECREF(op->func_module);
 	Py_DECREF(op->func_name);
 	Py_XDECREF(op->func_defaults);
 	Py_XDECREF(op->func_doc);
@@ -405,6 +428,11 @@ func_traverse(PyFunctionObject *f, visitproc visit, void *arg)
 		if (err)
 			return err;
 	}
+	if (f->func_module) {
+		err = visit(f->func_module, arg);
+		if (err)
+			return err;
+	}
 	if (f->func_defaults) {
 		err = visit(f->func_defaults, arg);
 		if (err)
diff --git a/Objects/methodobject.c b/Objects/methodobject.c
index a1f325d..aa64ff1 100644
--- a/Objects/methodobject.c
+++ b/Objects/methodobject.c
@@ -2,11 +2,12 @@
 /* Method object implementation */
 
 #include "Python.h"
+#include "structmember.h"
 
 static PyCFunctionObject *free_list = NULL;
 
 PyObject *
-PyCFunction_New(PyMethodDef *ml, PyObject *self)
+PyCFunction_NewEx(PyMethodDef *ml, PyObject *self, PyObject *module)
 {
 	PyCFunctionObject *op;
 	op = free_list;
@@ -22,6 +23,8 @@ PyCFunction_New(PyMethodDef *ml, PyObject *self)
 	op->m_ml = ml;
 	Py_XINCREF(self);
 	op->m_self = self;
+	Py_XINCREF(module);
+	op->m_module = module;
 	_PyObject_GC_TRACK(op);
 	return (PyObject *)op;
 }
@@ -121,6 +124,7 @@ meth_dealloc(PyCFunctionObject *m)
 {
 	_PyObject_GC_UNTRACK(m);
 	Py_XDECREF(m->m_self);
+	Py_XDECREF(m->m_module);
 	m->m_self = (PyObject *)free_list;
 	free_list = m;
 }
@@ -145,10 +149,18 @@ meth_get__name__(PyCFunctionObject *m, void *closure)
 static int
 meth_traverse(PyCFunctionObject *m, visitproc visit, void *arg)
 {
-	if (m->m_self != NULL)
-		return visit(m->m_self, arg);
-	else
-		return 0;
+	int err;
+	if (m->m_self != NULL) {
+		err = visit(m->m_self, arg);
+		if (err)
+			return err;
+	}
+	if (m->m_module != NULL) {
+		err = visit(m->m_module, arg);
+		if (err)
+			return err;
+	}
+	return 0;
 }
 
 static PyObject *
@@ -174,6 +186,13 @@ static PyGetSetDef meth_getsets [] = {
 	{0}
 };
 
+#define OFF(x) offsetof(PyCFunctionObject, x)
+
+static PyMemberDef meth_members[] = {
+	{"__module__",    T_OBJECT,     OFF(m_module),       READONLY},
+	{NULL}
+};
+
 static PyObject *
 meth_repr(PyCFunctionObject *m)
 {
@@ -250,7 +269,7 @@ PyTypeObject PyCFunction_Type = {
 	0,					/* tp_iter */
 	0,					/* tp_iternext */
 	0,					/* tp_methods */
-	0,					/* tp_members */
+	meth_members,				/* tp_members */
 	meth_getsets,				/* tp_getset */
 	0,					/* tp_base */
 	0,					/* tp_dict */
@@ -308,6 +327,7 @@ Py_FindMethodInChain(PyMethodChain *chain, PyObject *self, char *name)
 		for (; ml->ml_name != NULL; ml++) {
 			if (name[0] == ml->ml_name[0] &&
 			    strcmp(name+1, ml->ml_name+1) == 0)
+				/* XXX */
 				return PyCFunction_New(ml, self);
 		}
 		chain = chain->link;
@@ -338,3 +358,17 @@ PyCFunction_Fini(void)
 		PyObject_GC_Del(v);
 	}
 }
+
+/* PyCFunction_New() is now just a macro that calls PyCFunction_NewEx(),
+   but it's part of the API so we need to keep a function around that
+   existing C extensions can call.
+*/
+   
+#undef PyCFunction_New
+PyAPI_FUNC(PyObject *) PyCFunction_New(PyMethodDef *, PyObject *);
+
+PyObject *
+PyCFunction_New(PyMethodDef *ml, PyObject *self)
+{
+	return PyCFunction_NewEx(ml, self, NULL);
+}
diff --git a/Python/exceptions.c b/Python/exceptions.c
index 16b6738..0080694 100644
--- a/Python/exceptions.c
+++ b/Python/exceptions.c
@@ -126,22 +126,27 @@ Exception\n\
 static int
 populate_methods(PyObject *klass, PyObject *dict, PyMethodDef *methods)
 {
+    PyObject *module;
+    int status = -1;
+
     if (!methods)
 	return 0;
 
+    module = PyString_FromString("exceptions");
+    if (!module)
+	return 0;
     while (methods->ml_name) {
 	/* get a wrapper for the built-in function */
-	PyObject *func = PyCFunction_New(methods, NULL);
+	PyObject *func = PyCFunction_NewEx(methods, NULL, module);
 	PyObject *meth;
-	int status;
 
 	if (!func)
-	    return -1;
+	    goto status;
 
 	/* turn the function into an unbound method */
 	if (!(meth = PyMethod_New(func, NULL, klass))) {
 	    Py_DECREF(func);
-	    return -1;
+	    goto status;
 	}
 
 	/* add method to dictionary */
@@ -151,11 +156,14 @@ populate_methods(PyObject *klass, PyObject *dict, PyMethodDef *methods)
 
 	/* stop now if an error occurred, otherwise do the next method */
 	if (status)
-	    return status;
+	    goto status;
 
 	methods++;
     }
-    return 0;
+    status = 0;
+ status:
+    Py_DECREF(module);
+    return status;
 }
 
 
diff --git a/Python/modsupport.c b/Python/modsupport.c
index bca3d6f..41e0c82 100644
--- a/Python/modsupport.c
+++ b/Python/modsupport.c
@@ -33,7 +33,7 @@ PyObject *
 Py_InitModule4(char *name, PyMethodDef *methods, char *doc,
 	       PyObject *passthrough, int module_api_version)
 {
-	PyObject *m, *d, *v;
+	PyObject *m, *d, *v, *n;
 	PyMethodDef *ml;
 	if (!Py_IsInitialized())
 	    Py_FatalError("Interpreter not initialized (version mismatch?)");
@@ -46,6 +46,15 @@ Py_InitModule4(char *name, PyMethodDef *methods, char *doc,
 		if (PyErr_Warn(PyExc_RuntimeWarning, message)) 
 			return NULL;
 	}
+	/* Make sure name is fully qualified.
+
+	   This is a bit of a hack: when the shared library is loaded,
+	   the module name is "package.module", but the module calls
+	   Py_InitModule*() with just "module" for the name.  The shared
+	   library loader squirrels away the true name of the module in
+	   _Py_PackageContext, and Py_InitModule*() will substitute this
+	   (if the name actually matches).
+	*/
 	if (_Py_PackageContext != NULL) {
 		char *p = strrchr(_Py_PackageContext, '.');
 		if (p != NULL && strcmp(name, p+1) == 0) {
@@ -57,6 +66,9 @@ Py_InitModule4(char *name, PyMethodDef *methods, char *doc,
 		return NULL;
 	d = PyModule_GetDict(m);
 	if (methods != NULL) {
+		n = PyString_FromString(name);
+		if (n == NULL)
+			return NULL;
 		for (ml = methods; ml->ml_name != NULL; ml++) {
 			if ((ml->ml_flags & METH_CLASS) ||
 			    (ml->ml_flags & METH_STATIC)) {
@@ -65,7 +77,7 @@ Py_InitModule4(char *name, PyMethodDef *methods, char *doc,
 						" METH_CLASS or METH_STATIC");
 				return NULL;
 			}
-			v = PyCFunction_New(ml, passthrough);
+			v = PyCFunction_NewEx(ml, passthrough, n);
 			if (v == NULL)
 				return NULL;
 			if (PyDict_SetItemString(d, ml->ml_name, v) != 0) {