Trent Mick <trentm@activestate.com>:
The common technique for printing out a pointer has been to cast to a long
and use the "%lx" printf modifier. This is incorrect on Win64 where casting
to a long truncates the pointer. The "%p" formatter should be used instead.
The problem as stated by Tim:
> Unfortunately, the C committee refused to define what %p conversion "looks
> like" -- they explicitly allowed it to be implementation-defined. Older
> versions of Microsoft C even stuck a colon in the middle of the address (in
> the days of segment+offset addressing)!
The result is that the hex value of a pointer will maybe/maybe not have a 0x
prepended to it.
Notes on the patch:
There are two main classes of changes:
- in the various repr() functions that print out pointers
- debugging printf's in the various thread_*.h files (these are why the
patch is large)
Closes SourceForge patch #100505.
diff --git a/Objects/classobject.c b/Objects/classobject.c
index 4653d27..17b7bf4 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -353,11 +353,11 @@
else
name = PyString_AsString(op->cl_name);
if (mod == NULL || !PyString_Check(mod))
- sprintf(buf, "<class ?.%.100s at %lx>", name, (long)op);
+ sprintf(buf, "<class ?.%.100s at %p>", name, op);
else
- sprintf(buf, "<class %.50s.%.50s at %lx>",
+ sprintf(buf, "<class %.50s.%.50s at %p>",
PyString_AsString(mod),
- name, (long)op);
+ name, op);
return PyString_FromString(buf);
}
@@ -805,12 +805,12 @@
cname = "?";
PyErr_Clear();
if (mod == NULL || !PyString_Check(mod))
- sprintf(buf, "<?.%.100s instance at %lx>",
- cname, (long)inst);
+ sprintf(buf, "<?.%.100s instance at %p>",
+ cname, inst);
else
- sprintf(buf, "<%.50s.%.50s instance at %lx>",
+ sprintf(buf, "<%.50s.%.50s instance at %p>",
PyString_AsString(mod),
- cname, (long)inst);
+ cname, inst);
return PyString_FromString(buf);
}
res = PyEval_CallObject(func, (PyObject *)NULL);
@@ -1704,8 +1704,8 @@
icname = PyString_AsString(iclassname);
else
icname = "?";
- sprintf(buf, "<method %.60s.%.60s of %.60s instance at %lx>",
- fcname, fname, icname, (long)self);
+ sprintf(buf, "<method %.60s.%.60s of %.60s instance at %p>",
+ fcname, fname, icname, self);
}
Py_XDECREF(funcname);
return PyString_FromString(buf);