Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!ulysses!allegra!princeton!udel!gatech!hao!ames!necntc!linus!philabs!spectrum!mrs
From: mrs@spectrum.UUCP
Newsgroups: comp.lang.fortran
Subject: Re: bug fix for f77 (4,3 bsd) entry statement ?
Keywords: f77, entry, bug
Message-ID: <3164@briar.Philips.Com>
Date: 17 Jan 88 01:45:58 GMT
References: <3124@briar.Philips.Com> <1290@vu-vlsi.UUCP>
Sender: news@philabs.Philips.Com
Reply-To: mrs@spectrum.UUCP (Mark R. Simpson)
Organization: Philips Laboratories, Briarcliff Manor, NY
Lines: 54
Posted: Sat Jan 16 20:45:58 1988

In my original article, I noted a bug in the UNIX 4.3 f77 compilier
with the entry statement.  A number of people replied with suggestions
on how to circumvent the difficulty, but they all involved either
1) changing the calling sequence, or 2)  not using the entry 
statement.  The simplist modification (of cousre I maybe biased since it
is the one I used) is to make use of fortran's
"call by location" argument passing. Specifically, the declaration 

	character chas*(*) 

is "equivalent" (and I use the form loosely) to

	character chas*1

since in both instances the location of chas is passed to the calling
routine.  Consequently, I neither have to change the calling sequence
or remove the entry statement and the code is compatible
across machines/operating systems. I agree, nevertheless, that the use
of the entry statement goes against the grain of structured programming. 

Here is the revised subroutine which now compilies.

      subroutine getc(char)
c old statement
c     character        char,chas*(*)
c new statement
      character        char,chas*1
      integer          n
c
      return
      entry      gets(chas,n)
      return
      end


Mark R. Simpson

Philips Laboratories                                    uunet!philabs!mrs
North American Philips Corporation                             or
Briarcliff Manor, NY 10510                          mrs@philabs.philips.com
(914) 945-6163







Mark R. Simpson

Philips Laboratories					uunet!philabs!mrs
North American Philips Corporation			       or
Briarcliff Manor, NY 10510			    mrs@philabs.philips.com
(914) 945-6163