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/Python/compile.c b/Python/compile.c
index 4373422f3140dbaa65ca0086eb0dab465017fc02..c69a95f389774c1cd6881758207219f647ddfea8 100644 (file)
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -130,8 +130,8 @@ code_repr(co)
                filename = PyString_AsString(co->co_filename);
        if (co->co_name && PyString_Check(co->co_name))
                name = PyString_AsString(co->co_name);
-       sprintf(buf, "<code object %.100s at %lx, file \"%.300s\", line %d>",
-               name, (long)co, filename, lineno);
+       sprintf(buf, "<code object %.100s at %p, file \"%.300s\", line %d>",
+               name, co, filename, lineno);
        return PyString_FromString(buf);
 }