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[Bug c/22485] pointer +- integer is never NULL
- From: "gdr at integrable-solutions dot net" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 15 Jul 2005 10:26:52 -0000
- Subject: [Bug c/22485] pointer +- integer is never NULL
- References: <20050714131031.22485.mattias@virtutech.se>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From gdr at integrable-solutions dot net 2005-07-15 10:26 -------
Subject: Re: pointer +- integer is never NULL
"mattias at virtutech dot se" <gcc-bugzilla@gcc.gnu.org> writes:
| ------- Additional Comments From mattias at virtutech dot se 2005-07-15 09:12 -------
| It could be made an option so the user can tell GCC whether to make
| standard-conforming code go as fast as possible or if arithmetic on null
| pointers (as a gcc extension, say) is needed. -fnull-pointer-arith?
|
| (In reply to comment #13)
| > Scanning a region of memory starting from zero, is not
| > exactly the kind of thing never done in practice.
|
| True, but that sort of code is already in danger, since GCC assumes that in
|
| x = *p;
| if (!p) shout();
|
| the condition is never true (even if it is possible to read from location 0).
True but that is not the kind of codes I'm talking about.
-- Gaby
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22485