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From: aslam@m.cs.uiuc.edu
Newsgroups: comp.sys.encore
Subject: Re: Has NCAR package been ported?
Message-ID: <37500003@m.cs.uiuc.edu>
Date: 4 Aug 88 07:06:00 GMT
References: <37500002@m.cs.uiuc.edu>
Lines: 62
Nf-ID: #R:m.cs.uiuc.edu:37500002:m.cs.uiuc.edu:37500003:000:1969
Nf-From: m.cs.uiuc.edu!aslam    Aug  4 02:06:00 1988



Well, I decided to dig in and find out what is causing problem with the
NCAR graphics package. A number of routines take their default values
from fortran blockdata. The files containing blockdata are compiled
as other .f files and archived in .a libraries. For some reason, 
Fortran Blockdata doesn't work if loaded from a library. Could someone 
tell me if I need to do anything special? 

Here is an example of what I mean. Consider the following two tiny files:
% 
% cat bd.f
        blockdata dummy
        common / A / ncp, mio
        data ncp, mio /10, 11/
        end
% 
% cat test.f
c test whether block data works
        common/A/ ncp, mio
        print *, 'ncp =', ncp, ' mio = ', mio
        stop
        end

First try compiling the files directly:

% f77 -v test.f bd.f
F77 release: 02.00.r051
test.f:
/usr/lib/fcom test.f -X110 -X154 -X85 -X22 -X64 -X74 -X151 -X88 -X100 -X9 -X39 -X230 -X211 -Z54 -X183 -X80 -ga -X71 -X102 -X50 -X193 -X75
Fortran-32000 1.8.4 Copyright (C) 1983,1984,1985,1986,1987 Green Hills Software, Inc. All rights reserved.
Release 2.0.r051
bd.f:
/usr/lib/fcom bd.f -X110 -X154 -X85 -X22 -X64 -X74 -X151 -X88 -X100 -X9 -X39 -X230 -X211 -Z54 -X183 -X80 -ga -X71 -X102 -X50 -X193 -X75
Fortran-32000 1.8.4 Copyright (C) 1983,1984,1985,1986,1987 Green Hills Software, Inc. All rights reserved.
Release 2.0.r051
/bin/ld /lib/crt0.o test.o bd.o -lF77 -lI77 -lU77 -ltermcap -lm -lc
% 
% a.out
  ncp =  10   mio =   11    *** This is correct ***


Put the blockdata containing file into a library and then use it.

% ar rv bdlib.a bd.o
a - bd.o
ar: creating bdlib.a
% ranlib bdlib.a
% f77 test.o bdlib.a
% a.out
  ncp =  0   mio =   0   *** What!!! ***
%  

Is there something I need to specifiy on the f77 or the `ar' command to get
to the block data and have it initialize the common area?

Sohail Aslam
Department of Computer Science
University of Illinois
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