20011229: McIDAS7.8-04

>From: James Frysinger <address@hidden>
>Organization: College of Charleston
>Keywords: 200111061842.fA6Igt112242 LDM binary install

Jim,

re: look in makelog to see why convdlm did not get built

>I pulled makelog up into kedit and did a search on convdlm. Here's what I 
>got:
>
>.....at the very top of the file:
>./mccomp -vendor -I. -I../netcdf/libsrc -I../jpeg -I../zlib -c convdlmc.c
>rm -f convdlmc.o
>gcc -c -O -ansi -D_GNU_SOURCE -I/usr/X11R6/include -I. -I../netcdf/libsrc 
>-I../jpeg -I../zlib convdlmc.c
>compile        convdlmc.c:             done
>./mccomp -vendor -I. -I../netcdf/libsrc -I../jpeg -I../zlib -c convdlmf.f
>rm -f convdlmf.o
>mcfc -c -I. -I../netcdf/libsrc -I../jpeg -I../zlib convdlmf.f
>convdlmf.f:
>   convdlm:
>   nchars:
>   len_trim:
>compile        convdlmf.f:             done
>./mccomp -s -vendor -o convdlm convdlmc.o convdlmf.o
>mcfc -s -o convdlm convdlmc.o convdlmf.o -L/usr/local/lib -L/usr/X11R6/lib 
>-lf2c -ldl -lm
>/usr/lib/libf2c.so: undefined reference to `MAIN__'
>collect2: ld returned 1 exit status
>link   convdlm:                done

OK, so now we know why convdlm did not get linked: the linker was trying
to use the shared f2c library, libf2c.so.  This library does not contain
the MAIN__ entry point that is needed, so the link fails.  This is
addressed in the Notes and Warnings document of the online McIDAS
web pages:

http://www.unidata.ucar.edu/packages/mcidas/780/mcx/warnings_mcx.html

under the 'gcc/f2c Users' link which notes:

  use the static f2c library, libf2c.a, when linking
  
       You need to link against the static f2c library, libf2c.a, since
       the shared version does not contain the needed entry point
       MAIN__.
  
   ...
  
  Since one must link against the static f2c library, libf2c.a, one
  should be aware of the following procedure:
  
  As root: 
  
       Type: mkdir /usr/local/lib
       Type: ln -s /usr/lib/libf2c.a /usr/local/lib/libf2c.a
  
  As the user mcidas: 
  
  Define the environment variable LD_LIBRARY_PATH so that the
  /user/local/lib directory is searched before others when programs are
  linked. For C-shell users, LD_LIBRARY_PATH would be set in .cshrc as
  follows:
  
       Type: cd ~mcidas
  
       Edit .chsrc and add:
  
       setenv LD_LIBRARY_PATH /usr/local/lib:/lib:/usr/lib
  
  After modifying .cshrc, make sure to make the changes active in your
  session:
  
       Type: source .cshrc


Now, it may well be the case that the SuSE distribution comes with
the GNU Fortran compiler, g77.  If so, I would assume that it would get
installed in the same directory as gcc so that if:

which gcc

works then:

which g77

should also work.  If this is the case, I recommend that you switch to
use of the gcc/g77 combination for building McIDAS.  This capability,
after all, was one of the biggest reasons for the 7.804 addendum.

To use g77, you will need to:

1) edit makefile and change:

VENDOR            = -vendor
# VENDOR          = -gcc
# VENDOR          = -g77

to:

# VENDOR          = -vendor
# VENDOR          = -gcc
VENDOR            = -g77

2) edit .cshrc and modify the defines of CC, CPPFLAGS, etc. for use of
   gcc/g77.  The defines will end up looking like:

# -- GNU gcc and g77 --
setenv CC gcc
setenv CPPFLAGS "-DNDEBUG -Df2cFortran"
setenv CFLAGS -O
setenv FC g77
setenv FFLAGS "-O -Wuninitialized -fno-automatic"
setenv CXX

3) after making the changes in .cshrc, you must source it to make the
   changes active:

source .cshrc

4) finally, restart your build after clobbering all previous compile output:

cd mcidas7.8/src
make clobber
make all

Taking this route allows you to avoid having to setup the static libf2c.a
library as discussed in Notes and Warnings.  It should be a smoother ride
from here.

>By the way, I used the new distribution, SuSE 7.3, to rebuild my system>
>The kernel here is 2.4.10, but that should have no effect on the build. 
>Libraries, maybe?

The problem is, indeed, a library one, but it is a known problem and has
a well documented workaround.

Tom