Re: Ada's Assembly Language Comments

[fjh@murlibobo.cs.mu.OZ.AU (Fergus Henderson)]

Samuel Mize <smize@link.com> writes:

>>...The only justifications I have
>> heard seem rather spurious.  (For example: "a student once had
>> compilation problems when an open coment block went off the right hand
>> of the screen with an editor which had line wrapping turned off.")
>
>How about: Experienced professional programmers have accidentally
>commented out good code and accidentally left in bad code, causing
>system failures.  We're planning to build mission-critical and
>life-critical systems, so we want to eliminate that risk.

For further evidence that this happens even to experienced professional
programmers, here is an extract from /usr/include/sys/kern/queue.h
on the alpha-dec-osf3.2 system that I'm using.

	/*
	 *	Macro:		queue_init
	 *	Function:
	 *		Initialize the given queue.
	 *	Header:
	 *		void queue_init(q)
	 *			queue_t		q;	/* MODIFIED*/
	 */
	#define queue_init(q)	((q)->next = (q)->prev = q)

The only reason that this code compiles at all is that it is usually
#ifdef'd out.

--
Fergus Henderson <fjh@cs.mu.oz.au>   |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>   |  of excellence is a lethal habit"
PGP: finger fjh@128.250.37.3         |     -- the last words of T. S. Garp.