;; -*- Hen -*-

(define (dynld-name fn)		
  (make-pathname #f fn ##sys#load-dynamic-extension))	

(define (mpi-try-compile header ldflags cppflags)
  (and (try-compile 
	(string-append header "\n" 
			"int main(int argc, char **argv) { MPI_Init(&argc, &argv); return 0; }\n")
	ldflags: ldflags
	cflags: cppflags
	)
       (cons ldflags cppflags)))

(define-syntax mpi-test 
  (syntax-rules ()
    ((_ (flags ...))
     (condition-case (mpi-try-compile flags ...)
		     (t ()    #f)))))

(define mpi-dir (get-environment-variable "MPI_DIR"))

(define ld+cpp-options
  (or 
   (and mpi-dir (mpi-test ("#include <mpi.h>" 
			   (sprintf "-lmpi -L~S" (make-pathname mpi-dir "lib") )
			   (sprintf "-I~S -L~S" 
				    (make-pathname mpi-dir "include") 
				    (make-pathname mpi-dir "lib") ))
			  ))
   (mpi-test ("#include <mpi.h>" "-lmpi" ""))
   (mpi-test ("#include <mpi.h>" "-lmpi" "-I/usr/include/mpi"))
   (mpi-test ("#include <mpi.h>" "-lmpi" "-I/usr/lib/openmpi/include"))
   (error "unable to figure out location of MPI library; try setting environment variable MPI_DIR to the proper location")))

(compile -S -O2 -d0 -I. -s mpi.scm  -j mpi 
	 -L "\"" ,(car ld+cpp-options) "\"" 
	 -C "\"" ,(cdr ld+cpp-options) "\"")
(compile -O2 -d0 -s mpi.import.scm)

(install-extension

  ; Name of your extension:
  'mpi

  ; Files to install for your extension:
  `(,(dynld-name "mpi") ,(dynld-name "mpi.import") )
    
  ; Assoc list with properties for your extension:
  `((version 1.17)
    ))