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/intobject.c b/Objects/intobject.c
index 2e8939e..d182b30 100644
--- a/Objects/intobject.c
+++ b/Objects/intobject.c
@@ -957,8 +957,8 @@
i++, p++) {
if (PyInt_Check(p) && p->ob_refcnt != 0)
fprintf(stderr,
- "# <int at %lx, refcnt=%d, val=%ld>\n",
- (long)p, p->ob_refcnt, p->ob_ival);
+ "# <int at %p, refcnt=%d, val=%ld>\n",
+ p, p->ob_refcnt, p->ob_ival);
}
list = list->next;
}