dnl -*- shell-script -*-
dnl
dnl Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
dnl                         University Research and Technology
dnl                         Corporation.  All rights reserved.
dnl Copyright (c) 2004-2005 The University of Tennessee and The University
dnl                         of Tennessee Research Foundation.  All rights
dnl                         reserved.
dnl Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
dnl                         University of Stuttgart.  All rights reserved.
dnl Copyright (c) 2004-2005 The Regents of the University of California.
dnl                         All rights reserved.
dnl Copyright (c) 2009      Oak Ridge National Labs.  All rights reserved.
dnl Copyright (c) 2009-2012 Cisco Systems, Inc.  All rights reserved.
dnl $COPYRIGHT$
dnl 
dnl Additional copyrights may follow
dnl 
dnl $HEADER$
dnl


AC_DEFUN([OMPI_FORTRAN_FIND_EXT_SYMBOL_CONVENTION], [
    AC_REQUIRE([AC_PROG_NM])
    AC_REQUIRE([AC_PROG_GREP])
    OPAL_VAR_SCOPE_PUSH([FCFLAGS_NEW LDFLAGS_NEW FLAG])

    # invalidate cache if result came from a run where FORTRAN was disabled
    if test "$ompi_cv_fortran_external_symbol" = "skipped" ; then
        unset ompi_cv_fortran_external_symbol
    fi

    AC_CACHE_CHECK([$FORTRAN external symbol convention],
        [ompi_cv_fortran_external_symbol],
        [if test "$FC" = "none" -o "$OMPI_WANT_FORTRAN_BINDINGS" = "0"; then
             ompi_cv_fortran_external_symbol="skipped"
         else
             cat >conftest.f <<EOF
       subroutine FOO_bar(a)
       integer a
       a = 1
       return
       end
EOF
             # Try without certain optimization flags, which produce object
             # files without the required external symbols;
             # e.g. option -fast turns on -ipo on Intel Compilers 11.0
             FCFLAGS_NEW=""
             LDFLAGS_NEW=""
             case $FC in
                 ifort)
                     for FLAG in $FCFLAGS ; do
                         case $FLAG in
                             -fast) ;;
                             -ipo*) ;;
                             *)     FCFLAGS_NEW="$FCFLAGS_NEW $FLAG" ;;
                         esac
                     done
                     for FLAG in $LDFLAGS ; do
                         case $FLAG in
                             -fast) ;;
                             -ipo*) ;;
                             *)     LDFLAGS_NEW="$LDFLAGS_NEW $FLAG" ;;
                         esac
                     done
                     OPAL_LOG_MSG([Try with new FCFLAGS: $FCFLAGS_NEW   and new LDFLAGS:$LDFLAGS_NEW])
                 ;;
                 *)
                     FCFLAGS_NEW="$FCFLAGS"
                     LDFLAGS_NEW="$LDFLAGS"
                 ;;
             esac

             happy=1
             OPAL_LOG_COMMAND([$FC $FCFLAGS_NEW -c conftest.f $LDFLAGS_NEW $LIBS],
                 [if $NM conftest.o | $GREP foo_bar__ >/dev/null 2>&1 ; then
                      ompi_cv_fortran_external_symbol="double underscore"
                  elif $NM conftest.o | $GREP foo_bar_ >/dev/null 2>&1 ; then
                      ompi_cv_fortran_external_symbol="single underscore"
                  elif $NM conftest.o | $GREP FOO_bar >/dev/null 2>&1 ; then
                      ompi_cv_fortran_external_symbol="mixed case"
                  elif $NM conftest.o | $GREP foo_bar >/dev/null 2>&1 ; then
                      ompi_cv_fortran_external_symbol="no underscore"
                  elif $NM conftest.o | $GREP FOO_BAR >/dev/null 2>&1 ; then
                      ompi_cv_fortran_external_symbol="upper case"
                  else
                      $NM conftest.o >conftest.out 2>&1
                      OPAL_LOG_MSG([Could not determine Fortran naming convention. Output from $NM:])
                      OPAL_LOG_FILE([conftest.out])
                      happy=0
                  fi],
                 [AC_MSG_ERROR([Fortran compiler did not produce object file])])
         fi])

    # These values were all already set to 0 back up in
    # ompi_setup_mpi_fortran.m4, because this whole macro is
    # conditionally executed (i.e., it is not executed in the
    # --disable-mpi-fortran case).
    if test "$ompi_cv_fortran_external_symbol" = "double underscore" ; then
        ompi_fortran_double_underscore=1
    elif test "$ompi_cv_fortran_external_symbol" = "single underscore" ; then
        ompi_fortran_single_underscore=1
    elif test "$ompi_cv_fortran_external_symbol" = "mixed case" ; then
        ompi_fortran_caps=1
    elif test "$ompi_cv_fortran_external_symbol" = "no underscore" ; then
        ompi_fortran_plain=1
    elif test "$ompi_cv_fortran_external_symbol" = "upper case" ; then
        ompi_fortran_caps=1
    elif test "$ompi_cv_fortran_external_symbol" != "skipped" ; then
        AC_MSG_ERROR([unknown naming convention: $ompi_cv_fortran_external_symbol])
    fi

    OPAL_VAR_SCOPE_POP
    rm -rf conftest.*
])dnl


AC_DEFUN([OMPI_FORTRAN_MAKE_C_FUNCTION], [
    if test "$ompi_cv_fortran_external_symbol" = "double underscore" ; then
        # so the general rule is that if there is an _ in the function
        # name, then there are two trailing underscores.  Otherwise,
        # there is only one trailing underscore.  Any idea how to do
        # that with m4_translit?
        if echo $2 | $GREP _ >/dev/null 2>&1 ; then
            $1[=]m4_translit([$2], [A-Z], [a-z])[__]
        else
            $1[=]m4_translit([$2], [A-Z], [a-z])[_]
        fi
    elif test "$ompi_cv_fortran_external_symbol" = "single underscore" ; then
        $1[=]m4_translit([$2], [A-Z], [a-z])[_]
    elif test "$ompi_cv_fortran_external_symbol" = "mixed case" ; then
        $1[=]$2
    elif test "$ompi_cv_fortran_external_symbol" = "no underscore" ; then
        $1[=]m4_translit([$2], [A-Z], [a-z])
    elif test "$ompi_cv_fortran_external_symbol" = "upper case" ; then
        $1[=]m4_translit([$2], [a-z], [A-Z])
    else
        AC_MSG_ERROR([unknown naming convention: $ompi_cv_fortran_external_symbol])
    fi
])