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Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!wanginst!apollo!alan
From: alan@apollo.uucp (Alan Lehotsky)
Newsgroups: net.arch
Subject: Re: pointers to freshly minted func
Message-ID: <2c962626.7011@apollo.uucp>
Date: Wed, 19-Mar-86 09:27:33 EST
Article-I.D.: apollo.2c962626.7011
Posted: Wed Mar 19 09:27:33 1986
Date-Received: Sat, 22-Mar-86 03:19:08 EST
References: <2277@phri.UUCP> <5600043@uiucdcsb> <798@ttrdc.UUCP>
Reply-To: alan@apollo.UUCP (Alan Lehotsky)
Organization: Apollo Computer Inc., Chelmsford MA
Lines: 25
Summary: 

Regarding how SPICE on CDC would dynamically create procedures
and then execute them.  This is a classic FORTRAN trick and is
handled by the fact that syntactically, the only difference
between an array-reference and a subroutine or function call
is that the array must have been dimensioned in a DIMENSION
statement or a type-statement(among other places).

So, if your compiler handles "named-common" by giving it a "global"
name you can do:

    SUBROUTINE dummy
    COMMON  /dynamic/ I(1000)
C
C   "Compile" code into the array "I" (including correct entry-exit
C   sequences and parameter-passing conventions
C
    ......
    END

    SUBROUTINE hacker
    CALL dynamic(1,2,3)
    END

This used to work on IBM-360s.  This trick won't work on APOLLO-DOMAIN,
VAX/VMS or (I think) most UNIX systems.