dnl/*D

dnl PAC_PROG_F77_CMDARGS - Determine how to access the command line from

dnl Fortran 77

dnl

dnl Output Effects:

dnl  The following variables are set:

dnl.vb

dnl    F77_GETARG         - Statement to get an argument i into string s

dnl    F77_IARGC          - Routine to return the number of arguments

dnl    FXX_MODULE         - Module command when using Fortran 90 compiler

dnl    F77_GETARGDECL     - Declaration of routine used for F77_GETARG

dnl    F77_GETARG_FFLAGS  - Flags needed when compiling/linking

dnl    F77_GETARG_LDFLAGS - Flags needed when linking

dnl.ve

dnl If 'F77_GETARG' has a value, then that value and the values for these

dnl other symbols will be used instead.  If no approach is found, all of these

dnl variables will have empty values.

dnl If no other approach works and a file 'f77argdef' is in the directory, 

dnl that file will be sourced for the values of the above four variables.

dnl

dnl In most cases, you should add F77_GETARG_FFLAGS to the FFLAGS variable

dnl and F77_GETARG_LDFLAGS to the LDFLAGS variable, to ensure that tests are

dnl performed on the compiler version that will be used.

dnl

dnl 'AC_SUBST' is called for all six variables.

dnl

dnl One complication is that on systems with multiple Fortran compilers, 

dnl some libraries used by one Fortran compiler may have been (mis)placed

dnl in a common location.  We have had trouble with libg2c in particular.

dnl To work around this, we test whether iargc etc. work first.  This

dnl will catch most systems and will speed up the tests.

dnl

dnl Next, the libraries are only added if they are needed to complete a 

dnl link; they aren''t added just because they exist.

dnl

dnl f77argdef

dnl D*/

dnl

dnl Random notes

dnl You can export the command line arguments from C to the g77 compiler

dnl using

dnl    extern char **__libc_argv;

dnl    extern int  __libc_argc;

dnl    f_setarg( __libc_argc, __libc_argv );

dnl

AC_DEFUN([PAC_PROG_F77_CMDARGS],[

found_cached="yes"

AC_MSG_CHECKING([for routines to access the command line from Fortran 77])

AC_CACHE_VAL(pac_cv_prog_f77_cmdarg,

[

    AC_MSG_RESULT([searching...])

    found_cached="no"

    # First, we perform a quick check.  Does iargc and getarg work?

    fxx_module="${FXX_MODULE:-}"

    f77_getargdecl="${F77_GETARGDECL:-external getarg}"

    f77_getarg="${F77_GETARG:-call GETARG(i,s)}"

    f77_iargc="${F77_IARGC:-IARGC()}"

    #    

    # Grumble.  The Absoft Fortran compiler computes i - i as 0 and then

    # 1.0 / 0 at compile time, even though the code may never be executed.

    # What we need is a way to generate an error, so the second usage of i

    # was replaced with f77_iargc.  

    cat > conftest.f <

        program main

$fxx_module

        integer i, j

        character*20 s

        $f77_getargdecl

        i = 0

        $f77_getarg

        i=$f77_iargc

        if (i .gt. 1) then

            j = i - $f77_iargc

            j = 1.0 / j

        endif

        end

EOF

    found_answer="no"

    if test -z "$ac_fcompilelink" ; then

        ac_fcompilelink="${F77-f77} -o conftest $FFLAGS $flags conftest.f $LDFLAGS $LIBS 1>&AC_FD_CC"

    fi

    AC_MSG_CHECKING([whether ${F77-f77} $flags $libs works with GETARG and IARGC])

    if AC_TRY_EVAL(ac_fcompilelink) && test -x conftest ; then

	# Check that cross != yes so that this works with autoconf 2.52

	# Check that cross_compiling != yes so that this works with 

	# autoconf 2.6x for some (but almost certainly not all)x

	# Question: why do we test that this runs?  It looks like we

	# needed this for some old Fortran compilers that produced

	# executable code that then did not run.

	if test "$ac_cv_prog_f77_cross" != "yes" -a \

	        "$cross_compiling" != "yes" ; then

	    if ./conftest >/dev/null 2>&1 ; then

		found_answer="yes"

	        FXX_MODULE="$fxx_module"

		F77_GETARGDECL="$f77_getargdecl"

		F77_GETARG="$f77_getarg"

		F77_IARGC="$f77_iargc"

		AC_MSG_RESULT(yes)

     	    fi

        fi

    fi    

    if test $found_answer = "no" ; then

	AC_MSG_RESULT(no)

    # Grumph.  Here are a bunch of different approaches

    # We have several axes the check:

    # Library to link with (none, -lU77 (HPUX), -lg2c (LINUX f77))

    # PEPCF90 (Intel ifc)

    # The first line is a dummy

    # (we experimented with using a <space>, but this caused other 

    # problems because we need <space> in the IFS)

    trial_LIBS="0 -lU77 -lPEPCF90"

    if test "$NOG2C" != "1" ; then

        trial_LIBS="$trial_LIBS -lg2c"

    fi

    # Discard libs that are not availble:

    save_IFS="$IFS"

    # Make sure that IFS includes a space, or the tests that run programs

    # may fail

    IFS=" ""

"

    save_trial_LIBS="$trial_LIBS"

    trial_LIBS=""

    cat > conftest.f <

        program main

        end

EOF

    ac_fcompilelink_test='${F77-f77} -o conftest $FFLAGS conftest.f $LDFLAGS $libs $LIBS 1>&AC_FD_CC'

    for libs in $save_trial_LIBS ; do

	if test "$libs" = "0" ; then

	    lib_ok="yes"

        else

	    AC_MSG_CHECKING([whether Fortran 77 links with $libs])

	    if AC_TRY_EVAL(ac_fcompilelink_test) && test -x conftest ; then

		AC_MSG_RESULT([yes])

	        lib_ok="yes"

	    else

		AC_MSG_RESULT([no])

	        lib_ok="no"

	    fi

	fi

	if test "$lib_ok" = "yes" ; then

	    trial_LIBS="$trial_LIBS

$libs"

        fi

    done

    # Options to use when compiling and linking

    # +U77 is needed by HP Fortran to access getarg etc.

    # The -N109 was used for getarg before we realized that GETARG

    # was necessary with the (non standard conforming) Absoft compiler

    # (Fortran is monocase; Absoft uses mixedcase by default)

    # The -f is used by Absoft and is the compiler switch that folds 

    # symbolic names to lower case.  Without this option, the compiler

    # considers upper- and lower-case letters to be unique.

    # The -YEXT_NAMES=LCS will cause external names to be output as lower

    # case letter for Absoft F90 compilers (default is upper case)

    # The first line is "<space><newline>, the space is important

    # To make the Absoft f77 and f90 work together, we need to prefer the

    # upper case versions of the arguments.  They also require libU77.

    # -YCFRL=1 causes Absoft f90 to work with g77 and similar (f2c-based) 

    # Fortran compilers

    #

    # Problem:  The Intel efc compiler hangs when presented with -N109 .

    # The only real fix for this is to detect this compiler and exclude

    # the test.  We may want to reorganize these tests so that if we

    # can compile code without special options, we never look for them.

    # 

    using_intel_efc="no"

    pac_test_msg=`$F77 -V 2>&1 | grep 'Intel(R) Fortran Itanium'`

    if test "$pac_test_msg" != "" ; then

	using_intel_efc="yes"

    fi

    if test "$using_intel_efc" = "yes" ; then

        trial_FLAGS="000"

    else

        trial_FLAGS="000

-N109

-f

-YEXT_NAMES=UCS

-YEXT_NAMES=LCS

-YCFRL=1

+U77"

    fi

    # Discard options that are not available:

    # (IFS already saved above)

    IFS=" ""

"

    save_trial_FLAGS="$trial_FLAGS"

    trial_FLAGS=""

    for flag in $save_trial_FLAGS ; do

	if test "$flag" = " " -o "$flag" = "000" ; then

	    opt_ok="yes"

        else

            PAC_F77_CHECK_COMPILER_OPTION($flag,opt_ok=yes,opt_ok=no)

        fi

	if test "$opt_ok" = "yes" ; then

	    if test "$flag" = " " -o "$flag" = "000" ; then 

		fflag="" 

	    else 

		fflag="$flag" 

	    fi

	    # discard options that don't allow mixed-case name matching

	    cat > conftest.f <

        program main

        call aB()

        end

        subroutine Ab()

        end

EOF

	    if test -n "$fflag" ; then flagval="with $fflag" ; else flagval="" ; fi

	    AC_MSG_CHECKING([whether Fortran 77 routine names are case-insensitive $flagval])

	    dnl we can use double quotes here because all is already

            dnl evaluated

            ac_fcompilelink_test="${F77-f77} -o conftest $fflag $FFLAGS conftest.f $LDFLAGS $LIBS 1>&AC_FD_CC"

	    if AC_TRY_EVAL(ac_fcompilelink_test) && test -x conftest ; then

	        AC_MSG_RESULT(yes)

	    else

	        AC_MSG_RESULT(no)

	        opt_ok="no"

            fi

        fi

        if test "$opt_ok" = "yes" ; then

	    trial_FLAGS="$trial_FLAGS

$flag"

        fi

    done

    IFS="$save_IFS"

    # Name of routines.  Since these are in groups, we use a case statement

    # and loop until the end (accomplished by reaching the end of the

    # case statement

    # For one version of Nag F90, the names are 

    # call f90_unix_MP_getarg(i,s) and f90_unix_MP_iargc().

    trial=0

    while test -z "$pac_cv_prog_f77_cmdarg" ; do

        case $trial in 

	0) # User-specified values, if any

	   if test -z "$F77_GETARG" -o -z "$F77_IARGC" ; then 

	       trial=`expr $trial + 1`

	       continue 

           fi

           MSG="Using environment values of F77_GETARG etc."

	   ;;

	1) # Standard practice, uppercase (some compilers are case-sensitive)

	   FXX_MODULE=""

	   F77_GETARGDECL="external GETARG"

	   F77_GETARG="call GETARG(i,s)"

	   F77_IARGC="IARGC()"

	   MSG="GETARG and IARGC"

	   ;;

	2) # Standard practice, lowercase

	   FXX_MODULE=""

           F77_GETARGDECL="external getarg"

	   F77_GETARG="call getarg(i,s)"

	   F77_IARGC="iargc()"

	   MSG="getarg and iargc"

	   ;;

	3) # Posix alternative

	   FXX_MODULE=""

	   F77_GETARGDECL="external pxfgetarg"

	   F77_GETARG="call pxfgetarg(i,s,l,ier)"

	   F77_IARGC="ipxfargc()"

	   MSG="pxfgetarg and ipxfargc"

	   ;;

	4) # Nag f90_unix_env module

	   FXX_MODULE="        use f90_unix_env"

	   F77_GETARGDECL=""

	   F77_GETARG="call getarg(i,s)"

	   F77_IARGC="iargc()"

	   MSG="f90_unix_env module"

	   ;;

        5) # Nag f90_unix module

	   FXX_MODULE="        use f90_unix"

	   F77_GETARGDECL=""

	   F77_GETARG="call getarg(i,s)"

	   F77_IARGC="iargc()"

	   MSG="f90_unix module"

	   ;;

	6) # user spec in a file

	   if test -s f77argdef ; then

		. ./f77argdef

	       MSG="Using definitions in the file f77argdef"

	   else

	        trial=`expr $trial + 1`

		continue

	   fi

	   ;;

	7) # gfortran won't find getarg if it is marked as external 

	   FXX_MODULE=""

	   F77_GETARGDECL="intrinsic GETARG"

	   F77_GETARG="call GETARG(i,s)"

	   F77_IARGC="IARGC()"

	   MSG="intrinsic GETARG and IARGC"

	   ;;

        *) # exit from while loop

	   FXX_MODULE=""

	   F77_GETARGDECL=""

	   F77_GETARG=""

	   F77_IARGC=""

           break

	   ;;

	esac

	# Create the program.  Make sure that we can run it.

	# Force a divide-by-zero if there is a problem (but only at runtime!

        # (the Absoft compiler does divide-by-zero at compile time)

        cat > conftest.f <

        program main

$FXX_MODULE

        integer i, j

        character*20 s

        $F77_GETARGDECL

        i = 0

        $F77_GETARG

        i=$F77_IARGC

        if (i .gt. 1) then

            j = i - $F77_IARGC

            j = 1.0 / j

        endif

        end

EOF

    #

    # Now, try to find some way to compile and link that program, looping 

    # over the possibilities of options and libraries

        save_IFS="$IFS"

        IFS=" ""

"

        for libs in $trial_LIBS ; do

            if test -n "$pac_cv_prog_f77_cmdarg" ; then break ; fi

	    if test "$libs" = " " -o "$libs" = "0" ; then libs="" ; fi

            for flags in $trial_FLAGS ; do

	        if test "$flags" = " " -o "$flags" = "000"; then flags="" ; fi

                AC_MSG_CHECKING([whether ${F77-f77} $flags $libs works with $MSG])

		IFS="$save_IFS"

		dnl We need this here because we've fiddled with IFS

	        ac_fcompilelink_test="${F77-f77} -o conftest $FFLAGS $flags conftest.f $LDFLAGS $libs $LIBS 1>&AC_FD_CC"

		found_answer="no"

                if AC_TRY_EVAL(ac_fcompilelink_test) && test -x conftest ; then

		    if test "$ac_cv_prog_f77_cross" != "yes" -a \	 

		            "$cross_compiling" != "yes" ; then

			if ./conftest >/dev/null 2>&1 ; then

			    found_answer="yes"

			fi

		    else 

			found_answer="yes"

		    fi

                fi

	        IFS=" ""

"

		if test "$found_answer" = "yes" ; then

	            AC_MSG_RESULT([yes])

		    pac_cv_prog_f77_cmdarg="$MSG"

		    pac_cv_prog_f77_cmdarg_fflags="$flags"

		    pac_cv_prog_f77_cmdarg_ldflags="$libs"

		    break

	        else

                    AC_MSG_RESULT([no])

		    echo "configure: failed program was:" >&AC_FD_CC

                    cat conftest.f >&AC_FD_CC

	        fi

            done

        done

        IFS="$save_IFS"   

	rm -f conftest.*

        trial=`expr $trial + 1`   

    done

fi

pac_cv_F77_GETARGDECL="$F77_GETARGDECL"

pac_cv_F77_IARGC="$F77_IARGC"

pac_cv_F77_GETARG="$F77_GETARG"

pac_cv_FXX_MODULE="$FXX_MODULE"

])

if test "$found_cached" = "yes" ; then 

    AC_MSG_RESULT([$pac_cv_prog_f77_cmdarg])

elif test -z "$pac_cv_F77_IARGC" ; then

    AC_MSG_WARN([Could not find a way to access the command line from Fortran 77])

fi

# Set the variable values based on pac_cv_prog_xxx

F77_GETARGDECL="$pac_cv_F77_GETARGDECL"

F77_IARGC="$pac_cv_F77_IARGC"

F77_GETARG="$pac_cv_F77_GETARG"

FXX_MODULE="$pac_cv_FXX_MODULE"

F77_GETARG_FFLAGS="$pac_cv_prog_f77_cmdarg_fflags"

F77_GETARG_LDFLAGS="$pac_cv_prog_f77_cmdarg_ldflags"

AC_SUBST(F77_GETARGDECL)

AC_SUBST(F77_IARGC)

AC_SUBST(F77_GETARG)

AC_SUBST(FXX_MODULE)

AC_SUBST(F77_GETARG_FFLAGS)

AC_SUBST(F77_GETARG_LDFLAGS)

])