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* Re: c++/7354: NULL not defined correctly for g++ 64-bits
@ 2002-07-18 21:46 Gabriel Dos Reis
0 siblings, 0 replies; 3+ messages in thread
From: Gabriel Dos Reis @ 2002-07-18 21:46 UTC (permalink / raw)
To: nobody; +Cc: gcc-prs
The following reply was made to PR c++/7354; it has been noted by GNATS.
From: Gabriel Dos Reis <gdr@merlin.nerim.net>
To: craig_files@agilent.com
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: c++/7354: NULL not defined correctly for g++ 64-bits
Date: 19 Jul 2002 06:41:26 +0200
craig_files@agilent.com writes:
[...]
| NULL is defined (in stddef.h) for C++ as:
| #define NULL 0
| This is a problem in 64-bit world because the 0 is not a long int, but an int.
There is no requirement that NULL in C++ should be of type long int.
The only thing that is guaranteed is that it is an integral constant
expression, the exact type of which is unspecified -- it may
legitimately defined as '\0'. Programs depending on NULL being of a
particular value are broken. Furthermore, NULL is intended to be
used, suitably *converted*, to provide a null pointer. That means
that you'd better explicitly convert NULL to the appropriate target
(pointer) type when you use it.
[...]
| #define NULL ((void*)0)
This can't be.
-- Gaby
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: c++/7354: NULL not defined correctly for g++ 64-bits
@ 2002-07-20 9:08 lerdsuwa
0 siblings, 0 replies; 3+ messages in thread
From: lerdsuwa @ 2002-07-20 9:08 UTC (permalink / raw)
To: craig_files, gcc-bugs, gcc-prs, nobody
Synopsis: NULL not defined correctly for g++ 64-bits
State-Changed-From-To: open->closed
State-Changed-By: lerdsuwa
State-Changed-When: Sat Jul 20 09:08:34 2002
State-Changed-Why:
Not a bug.
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7354
^ permalink raw reply [flat|nested] 3+ messages in thread
* c++/7354: NULL not defined correctly for g++ 64-bits
@ 2002-07-18 15:16 craig_files
0 siblings, 0 replies; 3+ messages in thread
From: craig_files @ 2002-07-18 15:16 UTC (permalink / raw)
To: gcc-gnats
>Number: 7354
>Category: c++
>Synopsis: NULL not defined correctly for g++ 64-bits
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: unassigned
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Thu Jul 18 15:16:00 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:
>Release: 3.0.2
>Organization:
Agilent Technologies
>Environment:
System: HP-UX lathe B.11.00 A 9000/785 2000978003 two-user license
host: hppa64-hp-hpux11.00
build: hppa64-hp-hpux11.00
target: hppa64-hp-hpux11.00
configured with: ../gcc/configure --prefix=/usr/local/pa20_64 --enable-languages=c,c++ --host=hppa64-hp-hpux11.00 --target=hppa64-hp-hpux11.00 --with-ld=/usr/ccs/bin/ld --with-gnu-as --enable-libstdcxx-v3
>Description:
NULL is defined (in stddef.h) for C++ as:
#define NULL 0
This is a problem in 64-bit world because the 0 is not a long int, but an int.
Thus, NULL's most significant bits are not set to 0 on initialization and
comparing against NULL is not really 0x00000.
>How-To-Repeat:
>Fix:
#define NULL (long int)0 ?
or
#define NULL ((void*)0)
>Release-Note:
>Audit-Trail:
>Unformatted:
^ permalink raw reply [flat|nested] 3+ messages in thread
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2002-07-18 21:46 c++/7354: NULL not defined correctly for g++ 64-bits Gabriel Dos Reis
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2002-07-20 9:08 lerdsuwa
2002-07-18 15:16 craig_files
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