| Re: Call_external and link libraries - SunOS [message #4022] |
Wed, 19 April 1995 00:00 |
afl
Messages: 51
Registered: December 1994
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Member |
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In article <1995Apr19.092214.22596@rahman.earth.ox.ac.uk>, keith@earth.ox.ac.uk
(Keith Refson) writes:
|> I wonder if anyone can offer any suggestions on the following problem. I
|> am attempting to use CALL_EXTERNAL to interface to a FORTRAN
|> subroutine, using IDL 3.5 and Sun Fortran 1.4 running under SunOS
|> 4.1.3_U1. I have a C wrapper to pass the arguments to the FORTRAN.
|>
|> The problem is that the FORTRAN code makes calls to the math library
|> - simply the cosine function _Fcos. However when I build the
|> shared-object file, viz
|>
|> % cc -c -pic idl-link.c
|> % f77 -pic -c -O approx.f
|> % ld -o approx.so -assert pure-text *.o /usr/lang/SC1.0/libF77.so.1.4.1
|>
|> and call "approx.so", IDL crashes because the binary makes an
|> unsatisfied reference to _Fcos.
|>
|> Allright, _Fcos is in the math library /usr/lang/SC1.0/libm.a so I
|> should link *that* into assert.so just like I did with the FORTRAN
|> support library above. BUT in SunOS, there is only a static version
|> of this library! (ie no libm.so).
Keith,
Maybe you can explain this to me someday, but what I have
done (successfully under SOLARIS) is to link the static
libraries into my shared object! Huh? Yeah, that's what I
thought (and still do), but it works, and that is the
name of the game. If you figure out how/why, please let
me know. Here is an example I posted awhile back.
The first program is an IDL procedure. Note the compilation
and link statements that are executed using spawn.
Note also that I am using Solaris, and my libraries are in /usr/lib.
The second program is a simple FORTRAN program which uses numerous
mathematical intrinsic functions.
Good luck and let me know how it goes!
Andy Loughe
;=========================================================== ============
; Originator: Andrew F. Loughe
;
; *** SUN SOLARIS TEST ***
; Procedure to call a FORTRAN program from within IDL.
; The first 100 primes are computed in the FORTRAN program and
; passed into an IDL vector called prime_nums.
; We pass into the subroutine the number of primes desired.
;
; NOTE: A large number of "nonsense" function calls are made
; from within the FORTRAN subroutine in order to test
; that the link is robust. It found a problem with
; atan2 and datan2.
; **** Set these for yourself ****
DIR = '/bjer3/afl/ensemble/weights/src/idl/'
LIB_DIR = '/usr/lib/'
; This doesn't quite look like a shared object library!!
; May not need all three libraries, but for other tests I did need them.
compile = 1
if (compile eq 1) then begin
SRC = DIR + 'primes.f '
OBJ = DIR + 'primes.o '
OUT = DIR + 'primes.so '
LIB = LIB_DIR + 'libV77.a ' + LIB_DIR + 'libF77.a ' + $
LIB_DIR + 'libsunmath.a '
spawn, 'f77 -c -Kpic ' + SRC
spawn, 'ld -G -o ' + OUT + OBJ + LIB
endif
num_primes = 100L ; Want 100 primes.
prime_nums = lonarr(num_primes) ; Initialize the prime_nums vector.
; Call a FORTRAN program to do the computation.
a = CALL_EXTERNAL(DIR + 'primes.so', 'primes_', num_primes, prime_nums)
print, prime_nums(*)
end
C This routine accepts input from IDL's CALL_EXTERNAL Function.
C argc = The number of paramters being passed in from call_external
C argv = The vector of paramters being passed in from call_external
Subroutine primes(argc, argv) ! Called by IDL
Real argc, argv(*) ! Argc and argv are reals
Integer num_expected
parameter (num_expected = 2) ! Number of parameters
! expected by programmer
C Obtain # of arguements passed-in and check that this is correct.
j = LOC(argc)
if (j .ne. num_expected) then
return
endif
C Call subroutine with two parameters passed in.
call primes1( %val(argv(1)), %val(argv(2)) )
return
end
C=========================================================== ===========
C Originator: Andrew F. Loughe
C
C *** SUN SOLARIS TEST ***
C A rather simple, inefficient, poorly nested, quickly written,
C subroutine (apology accepted?) to compute the first 100 primes.
C It is used to demonstrate the ability of IDL to call a FORTRAN
C subroutine to accomplish some task, accepting an input paramter,
C and returning some values.
C num_primes is passed into this subroutine from IDL.
C
C NOTE:
C Some nonsense function calls are added to see if our link is robust.
C From this test I learned that atan2 and datan2 are symbols which
C could not be found.
subroutine primes1(num_primes, prime)
implicit none
integer i, j, icount, num_primes
integer prime(num_primes)
real r, r2
double precision d, d2
prime(1) = 2 ! By definition 1 is not prime.
prime(2) = 3
prime(3) = 5 ! Simple method requires specification
prime(4) = 7 ! of primes under 10.
icount = 4
C Loop through a large number of integers.
C Return only "num_primes" primes.
do 100 i = prime(icount)+2, 1e8, 2
C Test for an even divisor.
do 200 j = 3, int( sqrt( float(i) ) ), 2
if ( mod(i,j) .eq. 0 ) goto 100 ! Number not prime.
200 continue
C A prime has been found!
icount = icount + 1
prime(icount) = i
if (icount .gt. num_primes-1) goto 300 ! Only want num_primes
100 continue
C SOME NONSENSE FUNCTION CALLS:
C Sometimes a particular symbol is not found, so the CALL_EXTERNAL
C routine fails. Let's do some nonsense function calls to see if
C our link is robust. Sorry, not all FORTRAN functions are tested.
300 i = 100
r = 100.
d = 100.
i = iabs(i)
r = abs(r)
d = dabs(d)
i = max0(i, 2)
r = amax1(r, 3.)
d = dmax1(d, d*d)
i = min0(i, 2)
r = amin1(r, 3.)
d = dmin1(d, d*d)
r = sqrt(r)
d = dsqrt(d)
r = exp(r)
d = dexp(d)
r = alog( abs(r) )
d = dlog( dabs(d) )
r = alog10( abs(r) )
d = dlog10( dabs(d) )
r = sin(r)
d = dsin(d)
r = cos(r)
d = dcos(d)
i = 100
r = 100.
d = 100.
r2= .5
d2= .5
r = tan(r)
d = dtan(d)
r = asin(r)
d = dasin(d)
r = acos(r)
d = dacos(d)
r = atan(r)
d = datan(d)
C COULD NOT FIND THESE SYMBOLS
C r = atan2(r, r2)
C d = datan2(d, d2)
r = sinh(r)
d = dsinh(d)
r = cosh(r)
d = dcosh(d)
r = tanh(r)
d = dtanh(d)
return
end
--
Andrew F. Loughe email: afl@cdc.noaa.gov
University of Colorado, CIRES voice: (303) 492-0707
Campus Box 449 fax: (303) 497-7013
Boulder, CO 80309-0449 USA
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