Re: Sequent Dynix 4.4.2 problems with g++ compiler (w/fix suggested)

["Ronald F. Guilmette" <rfg at monkeys dot com>]

In message <200001252004.MAA07068@kankakee.wrs.com>, you wrote:

>> To: bug-gnu-gcc@gnu.org, Jay Vosburgh <fubar@sequent.com>
>> Date: Mon, 24 Jan 2000 19:19:19 -0800
>> From: "Ronald F. Guilmette" <rfg@monkeys.com>
>
>> Unfortunately, whoever implemented the C library bcopy() function
>> for Dynix 4.4.2 didn't look closely enough at the original bcopy()
>> man page from BSD UNIX, and it appears the Dynix 4.4.2 bcopy() _does
>> not_ properly handle the case where the input and output regions
>> overlap.
>
>In that case, I would say arrange for libiberty to include bcopy
>through the normal magic, and then gcc will just use it.  Maybe an
>autoconf test that checks bcopy on the system to see if it `really'
>does work, and it it doesn't, pull it in.


Adding a configure-time test to see if bcopy ``really works'', even with
overlapping input and output regions, is probably a Good Idea.

However if it doesn't work, then there is no need for a replacement in
any GNU-specific file.  Rather, the existing #define:

   #  define bcopy(src,dst,len) memmove((dst),(src),(len))

in the system.h file should simply be activated.

Ideally, of course, all of these non-standard calls to the non-standard
bcopy() function should be ripped out of the compilers and replaced by
_standard_ calls to the _standard_ functions memcpy() and/or memmove()
buy hey!  That's likely to happen just about the time hell freezes over.
(I think that I suggested this change to Stallman about 10 years ago and
got nowhere.  Well, at least I tried.)

-- rfg

P.S.  Another simple solution:  Just have the system.h file _always_ provide
the #define shown above... except for those systems that DO NOT provide a
standard-conforming memmove() function.

My estimate of the number of such systems now in active use: 0

The original ANSI C standard (requiring memmove) came out in 1988.  It
seems that 12 years has been more than ample time for people to adapt
their libraries to its requirements.