# New Ticket Created by Bruce Gray
# Please include the string: [perl #19232]
# in the subject line of all future correspondence about this issue.
# <URL: http://rt.perl.org/rt2/Ticket/Display.html?id=19232 >
In parrot.h (revision 1.45 2002-08-07), macros were defined
to eliminate warnings during pointer conversions. See:
http://rt.perl.org/rt2/Ticket/Display.html?id=16019
The definition of the macros is controlled by the first line of this block:
#if (INTVAL_SIZE == PTR_SIZE) && (UINTVAL_SIZE == PTR_SIZE)
# define INTVAL2PTR(any,d) (any)(d)
# define UINTVAL2PTR(any,d) (any)(d)
#else
# if PTR_SIZE == LONG_SIZE
# define INTVAL2PTR(any,d) (any)(unsigned long)(d)
# define UINTVAL2PTR(any,d) (any)(unsigned long)(d)
# else
# define INTVAL2PTR(any,d) (any)(unsigned int)(d)
# define UINTVAL2PTR(any,d) (any)(unsigned int)(d)
# endif
#endif
#define PTR2INTVAL(p) INTVAL2PTR(INTVAL,p)
#define PTR2UINTVAL(p) UINTVAL2PTR(UINTVAL,p)
--snip--
#define D2FPTR(x) UINTVAL2PTR(funcptr_t, PTR2UINTVAL(x))
#define F2DPTR(x) UINTVAL2PTR(void *, PTR2UINTVAL((funcptr_t) x))
I cannot find a definition for UINTVAL_SIZE anywhere. Being
undefined, it evaluates to 0, and so the #if always fails.
This means that some systems have been getting the wrong
macro definitions.
It would not be difficult to add Configure tests to define
UINTVAL_SIZE, but I think that it is not really needed.
Instead, the attached patch just changes the first line to:
#if PTR_SIZE == INTVAL_SIZE
( Is there any platform for which sizeof(signed foo) <>
sizeof(unsigned foo)? Would the C spec even allow it? If so,
I will be glad to write the Configure tests. )
I feel confident that this simpler change is the Right
Thing, but it could uncover other bugs, and I have no
esoteric platforms to test it on. Here is a summary of the
patch's effect on different platforms:
1) PTR_SIZE <> INTVAL_SIZE
No change.
2) PTR_SIZE == INTVAL_SIZE == LONG_SIZE (x86 Linux and Win32)
Intermediate casts to (unsigned long) removed, i.e.
(any)(unsigned long)(d)
becomes
(any)(d)
3) PTR_SIZE == INTVAL_SIZE <> LONG_SIZE
Intermediate casts to (unsigned int) removed, i.e.
(any)(unsigned int)(d)
becomes
(any)(d)
Under MS VC++ for .Net, this patch changes the results of
none of the tests; it only stops the "UINTVAL_SIZE is not
defined as a preprocessor macro" warnings that are given
with the -Wall option.
--
Hope this helps,
Bruce Gray
-- attachment 1 ------------------------------------------------------
url: http://rt.perl.org/rt2/attach/45713/35845/cf2db0/UINTVAL_SIZE.patch
Index: include/parrot/parrot.h
===================================================================
RCS file: /cvs/public/parrot/include/parrot/parrot.h,v
retrieving revision 1.58
diff -u -r1.58 parrot.h
--- include/parrot/parrot.h 12 Dec 2002 20:13:35 -0000 1.58
+++ include/parrot/parrot.h 17 Dec 2002 22:26:21 -0000
@@ -112,7 +112,7 @@
explicitly Configured in) which do limits checks?
A. D. Aug. 6, 2002.
*/
-#if (INTVAL_SIZE == PTR_SIZE) && (UINTVAL_SIZE == PTR_SIZE)
+#if PTR_SIZE == INTVAL_SIZE
# define INTVAL2PTR(any,d) (any)(d)
# define UINTVAL2PTR(any,d) (any)(d)
#else
