Path: utzoo!utgpu!water!watmath!clyde!rutgers!ukma!husc6!hao!noao!mcdsun!sunburn!gtx!al
From: al@gtx.com (0732)
Newsgroups: comp.lang.c
Subject: Re: Possible extension to C??
Message-ID: <525@gtx.com>
Date: 11 Jan 88 20:58:57 GMT
References: <3306@ihlpf.ATT.COM>
Reply-To: al@gtx.UUCP (Al Filipski 839-0732)
Organization: GTX Corporation, Phoenix
Lines: 35

In article <3306@ihlpf.ATT.COM> nevin1@ihlpf.UUCP (00704A-Liber,N.) writes:
>I have a proposal for a extension to C WHICH DOES NOT BREAK EXISTING CODE.
>
>I feel that *0 should be equal to 0 (at least for the data types char, short,
>int, long and 'pointer').
>

[I assume you really mean *x where x is a NULL pointer]

Run-time checking is contrary to the spirit and original design goals
of C (which were, if I recall some of the early scripture
correctly, that it be [1] not assembly language and [2] as fast as
possible.)

However, I think it would be great if more compilers offered a switch
to turn on as much run-time checking as possible.  Besides the null
pointer deref, one heuristic for catching some bad references
would be to look for (syntactic) occurrences of x[<exp>] where x is the
name of an array and insert code to check whether <exp> exceeds the
dimensioned bound.

This would help the re-tread Fortran programmers who write in the
traditional array[subscript] style, but would not help REAL C
programmers who write *(x + <exp>) or those who contrariwise prefer
(<exp>)[x] or those who just use pointers (not arrays) for everything.
It would just be a heuristic whose usefulness depends on your
programming style.

Doen anyone make a "run-time lint" compiler (short of an interpreter)
to put in checks for things like this?

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