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/floatobject.c b/Objects/floatobject.c
index 29ade28..f455ef5 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -806,8 +806,8 @@
char buf[100];
PyFloat_AsString(buf, p);
fprintf(stderr,
- "# <float at %lx, refcnt=%d, val=%s>\n",
- (long)p, p->ob_refcnt, buf);
+ "# <float at %p, refcnt=%d, val=%s>\n",
+ p, p->ob_refcnt, buf);
}
}
list = list->next;