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/object.c b/Objects/object.c
index 6eaff67..694aade 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -229,12 +229,12 @@
}
else {
if (op->ob_refcnt <= 0)
- fprintf(fp, "<refcnt %u at %lx>",
- op->ob_refcnt, (long)op);
+ fprintf(fp, "<refcnt %u at %p>",
+ op->ob_refcnt, op);
else if (op->ob_type->tp_print == NULL) {
if (op->ob_type->tp_repr == NULL) {
- fprintf(fp, "<%s object at %lx>",
- op->ob_type->tp_name, (long)op);
+ fprintf(fp, "<%s object at %p>",
+ op->ob_type->tp_name, op);
}
else {
PyObject *s;
@@ -280,8 +280,8 @@
return PyString_FromString("<NULL>");
else if (v->ob_type->tp_repr == NULL) {
char buf[120];
- sprintf(buf, "<%.80s object at %lx>",
- v->ob_type->tp_name, (long)v);
+ sprintf(buf, "<%.80s object at %p>",
+ v->ob_type->tp_name, v);
return PyString_FromString(buf);
}
else {