[pypy-commit] pypy cpyext-gc-support-2: Add one missing 'result_borrowed' to weakrefobject.py. Add comments

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: cpyext-gc-support-2
Changeset: r82264:2f74cfc0598e
Date: 2016-02-15 15:03 +0100
http://bitbucket.org/pypy/pypy/changeset/2f74cfc0598e/

Log:	Add one missing 'result_borrowed' to weakrefobject.py. Add comments
	to various other similar places

diff --git a/pypy/module/cpyext/dictobject.py b/pypy/module/cpyext/dictobject.py
--- a/pypy/module/cpyext/dictobject.py
+++ b/pypy/module/cpyext/dictobject.py
@@ -14,7 +14,8 @@
 
 PyDict_Check, PyDict_CheckExact = build_type_checkers("Dict")
 
- at cpython_api([PyObject, PyObject], PyObject, error=CANNOT_FAIL, result_borrowed=True)
+ at cpython_api([PyObject, PyObject], PyObject, error=CANNOT_FAIL,
+             result_borrowed=True)
 def PyDict_GetItem(space, w_dict, w_key):
     try:
         w_res = space.getitem(w_dict, w_key)
@@ -22,7 +23,7 @@
         return None
     # NOTE: this works so far because all our dict strategies store
     # *values* as full objects, which stay alive as long as the dict is
-    # alive and not modified.
+    # alive and not modified.  So we can return a borrowed ref.
     return w_res
 
 @cpython_api([PyObject, PyObject, PyObject], rffi.INT_real, error=-1)
@@ -61,7 +62,7 @@
         w_res = None
     # NOTE: this works so far because all our dict strategies store
     # *values* as full objects, which stay alive as long as the dict is
-    # alive and not modified.
+    # alive and not modified.  So we can return a borrowed ref.
     return w_res
 
 @cpython_api([PyObject, CONST_STRING], rffi.INT_real, error=-1)
diff --git a/pypy/module/cpyext/import_.py b/pypy/module/cpyext/import_.py
--- a/pypy/module/cpyext/import_.py
+++ b/pypy/module/cpyext/import_.py
@@ -1,7 +1,6 @@
 from pypy.interpreter import module
 from pypy.module.cpyext.api import (
     generic_cpy_call, cpython_api, PyObject, CONST_STRING)
-from pypy.module.cpyext.pyobject import borrow_from
 from rpython.rtyper.lltypesystem import lltype, rffi
 from pypy.interpreter.error import OperationError
 from pypy.interpreter.module import Module
@@ -56,7 +55,7 @@
     from pypy.module.imp.importing import reload
     return reload(space, w_mod)
 
- at cpython_api([CONST_STRING], PyObject)
+ at cpython_api([CONST_STRING], PyObject, result_borrowed=True)
 def PyImport_AddModule(space, name):
     """Return the module object corresponding to a module name.  The name
     argument may be of the form package.module. First check the modules
@@ -74,14 +73,16 @@
     w_mod = check_sys_modules_w(space, modulename)
     if not w_mod or space.is_w(w_mod, space.w_None):
         w_mod = Module(space, space.wrap(modulename))
-    return borrow_from(None, w_mod)
+        space.setitem(space.sys.get('modules'), space.wrap(modulename), w_mod)
+    # return a borrowed ref --- assumes one copy in sys.modules
+    return w_mod
 
- at cpython_api([], PyObject)
+ at cpython_api([], PyObject, result_borrowed=True)
 def PyImport_GetModuleDict(space):
     """Return the dictionary used for the module administration (a.k.a.
     sys.modules).  Note that this is a per-interpreter variable."""
     w_modulesDict = space.sys.get('modules')
-    return borrow_from(None, w_modulesDict)
+    return w_modulesDict     # borrowed ref
 
 @cpython_api([rffi.CCHARP, PyObject], PyObject)
 def PyImport_ExecCodeModule(space, name, w_code):
diff --git a/pypy/module/cpyext/listobject.py b/pypy/module/cpyext/listobject.py
--- a/pypy/module/cpyext/listobject.py
+++ b/pypy/module/cpyext/listobject.py
@@ -51,7 +51,8 @@
             "list index out of range"))
     w_list.ensure_object_strategy()  # make sure we can return a borrowed obj
     # XXX ^^^ how does this interact with CPyListStrategy?
-    return w_list.getitem(index)
+    w_res = w_list.getitem(index)
+    return w_res     # borrowed ref
 
 
 @cpython_api([PyObject, PyObject], rffi.INT_real, error=-1)
diff --git a/pypy/module/cpyext/pyerrors.py b/pypy/module/cpyext/pyerrors.py
--- a/pypy/module/cpyext/pyerrors.py
+++ b/pypy/module/cpyext/pyerrors.py
@@ -6,7 +6,7 @@
 from pypy.module.cpyext.api import cpython_api, CANNOT_FAIL, CONST_STRING
 from pypy.module.exceptions.interp_exceptions import W_RuntimeWarning
 from pypy.module.cpyext.pyobject import (
-    PyObject, PyObjectP, make_ref, from_ref, Py_DecRef, borrow_from)
+    PyObject, PyObjectP, make_ref, from_ref, Py_DecRef)
 from pypy.module.cpyext.state import State
 from pypy.module.cpyext.import_ import PyImport_Import
 from rpython.rlib import rposix, jit
@@ -33,7 +33,7 @@
     state = space.fromcache(State)
     if state.operror is None:
         return None
-    return state.operror.w_type
+    return state.operror.w_type     # borrowed ref
 
 @cpython_api([], lltype.Void)
 def PyErr_Clear(space):
diff --git a/pypy/module/cpyext/sequence.py b/pypy/module/cpyext/sequence.py
--- a/pypy/module/cpyext/sequence.py
+++ b/pypy/module/cpyext/sequence.py
@@ -64,7 +64,7 @@
     else:
         assert isinstance(w_obj, tupleobject.W_TupleObject)
         w_res = w_obj.wrappeditems[index]
-    return w_res
+    return w_res     # borrowed ref
 
 @cpython_api([PyObject], Py_ssize_t, error=CANNOT_FAIL)
 def PySequence_Fast_GET_SIZE(space, w_obj):
diff --git a/pypy/module/cpyext/tupleobject.py b/pypy/module/cpyext/tupleobject.py
--- a/pypy/module/cpyext/tupleobject.py
+++ b/pypy/module/cpyext/tupleobject.py
@@ -4,7 +4,7 @@
                                     build_type_checkers, PyObjectFields,
                                     cpython_struct, bootstrap_function)
 from pypy.module.cpyext.pyobject import (PyObject, PyObjectP, Py_DecRef,
-    borrow_from, make_ref, from_ref, decref,
+    make_ref, from_ref, decref,
     track_reference, make_typedescr, get_typedescr)
 from pypy.module.cpyext.pyerrors import PyErr_BadInternalCall
 from pypy.objspace.std.tupleobject import W_TupleObject
@@ -148,7 +148,7 @@
     if index < 0 or index >= size:
         raise OperationError(space.w_IndexError,
                              space.wrap("tuple index out of range"))
-    return ref.c_ob_item[index]
+    return ref.c_ob_item[index]     # borrowed ref
 
 @cpython_api([PyObject], Py_ssize_t, error=-1)
 def PyTuple_Size(space, ref):
diff --git a/pypy/module/cpyext/typeobject.py b/pypy/module/cpyext/typeobject.py
--- a/pypy/module/cpyext/typeobject.py
+++ b/pypy/module/cpyext/typeobject.py
@@ -646,7 +646,7 @@
     name = space.str_w(w_name)
     w_obj = w_type.lookup(name)
     # this assumes that w_obj is not dynamically created, but will stay alive
-    # until w_type is modified or dies
+    # until w_type is modified or dies.  Assuming this, we return a borrowed ref
     return w_obj
 
 @cpython_api([PyTypeObjectPtr], lltype.Void)
diff --git a/pypy/module/cpyext/weakrefobject.py b/pypy/module/cpyext/weakrefobject.py
--- a/pypy/module/cpyext/weakrefobject.py
+++ b/pypy/module/cpyext/weakrefobject.py
@@ -1,5 +1,5 @@
 from pypy.module.cpyext.api import cpython_api
-from pypy.module.cpyext.pyobject import PyObject, borrow_from
+from pypy.module.cpyext.pyobject import PyObject
 from pypy.module._weakref.interp__weakref import W_Weakref, proxy
 
 @cpython_api([PyObject, PyObject], PyObject)
@@ -30,19 +30,19 @@
     """
     return proxy(space, w_obj, w_callback)
 
- at cpython_api([PyObject], PyObject)
+ at cpython_api([PyObject], PyObject, result_borrowed=True)
 def PyWeakref_GetObject(space, w_ref):
     """Return the referenced object from a weak reference.  If the referent is
     no longer live, returns None. This function returns a borrowed reference.
     """
-    return PyWeakref_GET_OBJECT(space, w_ref)
+    return space.call_function(w_ref)     # borrowed ref
 
 @cpython_api([PyObject], PyObject, result_borrowed=True)
 def PyWeakref_GET_OBJECT(space, w_ref):
     """Similar to PyWeakref_GetObject(), but implemented as a macro that does no
     error checking.
     """
-    return space.call_function(w_ref)
+    return space.call_function(w_ref)     # borrowed ref
 
 @cpython_api([PyObject], PyObject)
 def PyWeakref_LockObject(space, w_ref):