[pypy-commit] pypy default: Give up and return a regular int from compute_unique_id(), with an explanation.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r69834:3a69dad4faf9
Date: 2014-03-10 08:06 +0100
http://bitbucket.org/pypy/pypy/changeset/3a69dad4faf9/

Log:	Give up and return a regular int from compute_unique_id(), with an
	explanation.

diff --git a/rpython/rlib/objectmodel.py b/rpython/rlib/objectmodel.py
--- a/rpython/rlib/objectmodel.py
+++ b/rpython/rlib/objectmodel.py
@@ -432,7 +432,11 @@
     costly depending on the garbage collector.  To remind you of this
     fact, we don't support id(x) directly.
     """
-    return id(x)      # XXX need to return r_longlong on some platforms
+    # The assumption with RPython is that a regular integer is wide enough
+    # to store a pointer.  The following intmask() should not loose any
+    # information.
+    from rpython.rlib.rarithmetic import intmask
+    return intmask(id(x))
 
 def current_object_addr_as_int(x):
     """A cheap version of id(x).
diff --git a/rpython/rlib/test/test_objectmodel.py b/rpython/rlib/test/test_objectmodel.py
--- a/rpython/rlib/test/test_objectmodel.py
+++ b/rpython/rlib/test/test_objectmodel.py
@@ -177,10 +177,13 @@
     assert h == getattr(foo, '__precomputed_identity_hash')
 
 def test_compute_unique_id():
+    from rpython.rlib.rarithmetic import intmask
     class Foo(object):
         pass
     foo = Foo()
-    assert compute_unique_id(foo) == id(foo)
+    x = compute_unique_id(foo)
+    assert type(x) is int
+    assert x == intmask(id(foo))
 
 def test_current_object_addr_as_int():
     from rpython.rlib.rarithmetic import intmask