Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!ttrdc!levy
From: levy@ttrdc.UUCP (Daniel R. Levy)
Newsgroups: comp.lang.fortran
Subject: Re: Semantics of local variables
Summary: use the SAVE statement
Message-ID: <2079@ttrdc.UUCP>
Date: 8 Jan 88 18:19:30 GMT
References: <2617@killer> <3669@aw>
Organization: AT&T, Skokie, IL
Lines: 30

In article <3669@aw>, firth@aw writes:
#> In article <2617@killer.UUCP> richardh@killer.UUCP (Richard Hargrove) writes:
#> >... [does] a DATA statement force ... [a] variable to have static 
#> >scope?
#> 
#> The quick answer: No.
#> 
#> You'll find it in ANSI X3.9-1978 para 17.3 (6)
#> 	"The execution of a RETURN statement or an END statement
#> 	 within a subprogram causes all entities within the subprogram
#> 	 to become undefined except for the following:
#> 	 ...
#> 	 (b) Initially defined entities that have neither been redefined
#> 	     nor become undefined
#> 	 ...
#> 	"
#> As you say, most compilers will let you get away with this, since they make
#> the variables static.  However, there are other legitimate implementations.
#> If you want to follow the standard, don't ever assume more than it guarantees.

This kind of behavior can also be assured by using the SAVE statement, e.g.,

       DATA FOO /1.0/
       ...
       SAVE FOO
-- 
|------------Dan Levy------------|  Path: ..!{akgua,homxb,ihnp4,ltuxa,mvuxa,
|         an Engihacker @        |  	<most AT&T machines>}!ttrdc!ttrda!levy
| AT&T Computer Systems Division |  Disclaimer?  Huh?  What disclaimer???
|--------Skokie, Illinois--------|