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Re: [Chicken-users] Request for comments on the SQLite3 egg API
From: |
Peter Keller |
Subject: |
Re: [Chicken-users] Request for comments on the SQLite3 egg API |
Date: |
Tue, 3 Jul 2007 16:52:28 -0500 |
User-agent: |
Mutt/1.4.2.1i |
On Wed, Jul 04, 2007 at 12:42:18AM +0700, Ivan Shmakov wrote:
> Well, I program C since 1995 or so (started to study x86
> assembler about the same time.) In my programs, I tend to
> distinguish NULL (or 0) from false. E. g., I'd write:
ASIDE:
As a small note. 0 is not entirely equivalent to NULL in one technical case.
You may not pass 0 through a ... and then check it for NULL in the callee. Case
in point execve("something", "something", "args", 0).
This is because the C spec says that ... types are promoted to an int,
which on 64 bit architectures, doesn't have to be the same size as a
pointer, which NULL often is. In this case, ripping off 64 bits from
the stack will rip off 32 bits too many since the bare 0 is be nature
an int sized quantity.
While NULL is often (void*)0 or (char*)0, I've seen esoteric platforms in which
it is just plainly 0.
So, really, you should check pointers against NULL, especially if they
were gotten through a ... .
-pete
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, Ivan Shmakov, 2007/07/02
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, Thomas Christian Chust, 2007/07/02
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, Ivan Shmakov, 2007/07/03
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, John Cowan, 2007/07/03
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, Thomas Christian Chust, 2007/07/03
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, Ivan Shmakov, 2007/07/03
- Re: [Chicken-users] Request for comments on the SQLite3 egg API,
Peter Keller <=
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, Thomas Christian Chust, 2007/07/04
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, Ivan Shmakov, 2007/07/06
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, Thomas Christian Chust, 2007/07/06
- Re: [Chicken-users] Request for comments on the SQLite3 egg API, John Cowan, 2007/07/06