# This file is part of Autoconf.                       -*- Autoconf -*-
# Fortran languages support.
# Copyright (C) 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free
# Software Foundation, Inc.

# This file is part of Autoconf.  This program is free
# software; you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the
# Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# Under Section 7 of GPL version 3, you are granted additional
# permissions described in the Autoconf Configure Script Exception,
# version 3.0, as published by the Free Software Foundation.
#
# You should have received a copy of the GNU General Public License
# and a copy of the Autoconf Configure Script Exception along with
# this program; see the files COPYINGv3 and COPYING.EXCEPTION
# respectively.  If not, see <http://www.gnu.org/licenses/>.

# Written by David MacKenzie, with help from
# Franc,ois Pinard, Karl Berry, Richard Pixley, Ian Lance Taylor,
# Roland McGrath, Noah Friedman, david d zuhn, and many others.


# Table of Contents:
#
# Preamble
#
# 0. Utility macros
#
# 1. Language selection
#    and routines to produce programs in a given language.
#
# 2. Producing programs in a given language.
#
# 3. Looking for a compiler
#    And possibly the associated preprocessor.
#
# 4. Compilers' characteristics.


## ---------- ##
## Preamble.  ##
## ---------- ##

# Fortran vs. Fortran 77:
#   This file contains macros for both "Fortran 77" and "Fortran", where
# the former is the "classic" autoconf Fortran interface and is intended
# for legacy F77 codes, while the latter is intended to support newer Fortran
# dialects.  Fortran 77 uses environment variables F77, FFLAGS, and FLIBS,
# while Fortran uses FC, FCFLAGS, and FCLIBS.  For each user-callable AC_*
# macro, there is generally both an F77 and an FC version, where both versions
# share the same _AC_*_FC_* backend.  This backend macro requires that
# the appropriate language be AC_LANG_PUSH'ed, and uses _AC_LANG_ABBREV and
# _AC_LANG_PREFIX in order to name cache and environment variables, etc.


## ------------------- ##
## 0. Utility macros.  ##
## ------------------- ##


# _AC_LIST_MEMBER_IF(ELEMENT, LIST, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
# ---------------------------------------------------------------------------
#
# Processing the elements of a list is tedious in shell programming,
# as lists tend to be implemented as space delimited strings.
#
# This macro searches LIST for ELEMENT, and executes ACTION-IF-FOUND
# if ELEMENT is a member of LIST, otherwise it executes
# ACTION-IF-NOT-FOUND.
AC_DEFUN([_AC_LIST_MEMBER_IF],
dnl Do some sanity checking of the arguments.
[m4_if([$1], , [m4_fatal([$0: missing argument 1])],
      [$2], , [m4_fatal([$0: missing argument 2])])]dnl
[  ac_exists=false
  for ac_i in $2; do
    if test x"$1" = x"$ac_i"; then
      ac_exists=true
      break
    fi
  done

  AS_IF([test x"$ac_exists" = xtrue], [$3], [$4])[]dnl
])# _AC_LIST_MEMBER_IF


# _AC_LINKER_OPTION(LINKER-OPTIONS, SHELL-VARIABLE)
# -------------------------------------------------
#
# Specifying options to the compiler (whether it be the C, C++ or
# Fortran 77 compiler) that are meant for the linker is compiler
# dependent.  This macro lets you give options to the compiler that
# are meant for the linker in a portable, compiler-independent way.
#
# This macro take two arguments, a list of linker options that the
# compiler should pass to the linker (LINKER-OPTIONS) and the name of
# a shell variable (SHELL-VARIABLE).  The list of linker options are
# appended to the shell variable in a compiler-dependent way.
#
# For example, if the selected language is C, then this:
#
#   _AC_LINKER_OPTION([-R /usr/local/lib/foo], foo_LDFLAGS)
#
# will expand into this if the selected C compiler is gcc:
#
#   foo_LDFLAGS="-Xlinker -R -Xlinker /usr/local/lib/foo"
#
# otherwise, it will expand into this:
#
#   foo_LDFLAGS"-R /usr/local/lib/foo"
#
# You are encouraged to add support for compilers that this macro
# doesn't currently support.
# FIXME: Get rid of this macro.
AC_DEFUN([_AC_LINKER_OPTION],
[if test "$ac_compiler_gnu" = yes; then
  for ac_link_opt in $1; do
    $2="[$]$2 -Xlinker $ac_link_opt"
  done
else
  $2="[$]$2 $1"
fi[]dnl
])# _AC_LINKER_OPTION


## ------------------------ ##
## 1a. Language selection.  ##
## ------------------------ ##


# AC_LANG(Fortran 77)
# -------------------
AC_LANG_DEFINE([Fortran 77], [f77], [F], [F77], [],
[ac_ext=f
ac_compile='$F77 -c $FFLAGS conftest.$ac_ext >&AS_MESSAGE_LOG_FD'
ac_link='$F77 -o conftest$ac_exeext $FFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&AS_MESSAGE_LOG_FD'
ac_compiler_gnu=$ac_cv_f77_compiler_gnu
])


# AC_LANG_FORTRAN77
# -----------------
AU_DEFUN([AC_LANG_FORTRAN77], [AC_LANG(Fortran 77)])


# _AC_FORTRAN_ASSERT
# ------------------
# Current language must be Fortran or Fortran 77.
m4_defun([_AC_FORTRAN_ASSERT],
[m4_if(_AC_LANG, [Fortran], [],
       [m4_if(_AC_LANG, [Fortran 77], [],
	      [m4_fatal([$0: current language is not Fortran: ] _AC_LANG)])])])


# _AC_FC
# ------
# Return F77 or FC, depending upon the language.
AC_DEFUN([_AC_FC],
[_AC_FORTRAN_ASSERT()dnl
AC_LANG_CASE([Fortran 77], [F77],
	     [Fortran],    [FC])])


## ----------------------- ##
## 2. Producing programs.  ##
## ----------------------- ##


# AC_LANG_PROGRAM(Fortran 77)([PROLOGUE], [BODY])
# -----------------------------------------------
# Yes, we discard the PROLOGUE.
m4_define([AC_LANG_PROGRAM(Fortran 77)],
[m4_ifval([$1],
       [m4_warn([syntax], [$0: ignoring PROLOGUE: $1])])dnl
      program main
$2
      end])


# _AC_LANG_IO_PROGRAM(Fortran 77)
# -------------------------------
# Produce source that performs I/O.
m4_define([_AC_LANG_IO_PROGRAM(Fortran 77)],
[AC_LANG_PROGRAM([],
[dnl
      open(unit=9,file='conftest.out')
      close(unit=9)
])])


# AC_LANG_CALL(Fortran 77)(PROLOGUE, FUNCTION)
# --------------------------------------------
# FIXME: This is a guess, help!
m4_define([AC_LANG_CALL(Fortran 77)],
[AC_LANG_PROGRAM([$1],
[      call $2])])


# AC_LANG_FUNC_LINK_TRY(Fortran 77)(FUNCTION)
# -------------------------------------------
m4_define([AC_LANG_FUNC_LINK_TRY(Fortran 77)],
[AC_LANG_PROGRAM([],
[      call $1])])

## ------------------------ ##
## 1b. Language selection.  ##
## ------------------------ ##


# AC_LANG(Fortran)
# ----------------
AC_LANG_DEFINE([Fortran], [fc], [FC], [FC], [Fortran 77],
[ac_ext=${ac_fc_srcext-f}
ac_compile='$FC -c $FCFLAGS $ac_fcflags_srcext conftest.$ac_ext >&AS_MESSAGE_LOG_FD'
ac_link='$FC -o conftest$ac_exeext $FCFLAGS $LDFLAGS $ac_fcflags_srcext conftest.$ac_ext $LIBS >&AS_MESSAGE_LOG_FD'
ac_compiler_gnu=$ac_cv_fc_compiler_gnu
])


## -------------------------------------------- ##
## 3. Looking for Compilers and Preprocessors.  ##
## -------------------------------------------- ##


# AC_LANG_PREPROC(Fortran 77)
# ---------------------------
# Find the Fortran 77 preprocessor.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
AC_DEFUN([AC_LANG_PREPROC(Fortran 77)],
[m4_warn([syntax],
	 [$0: No preprocessor defined for ]_AC_LANG)])

# AC_LANG_PREPROC(Fortran)
# ---------------------------
# Find the Fortran preprocessor.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
AC_DEFUN([AC_LANG_PREPROC(Fortran)],
[m4_warn([syntax],
	 [$0: No preprocessor defined for ]_AC_LANG)])


# AC_LANG_COMPILER(Fortran 77)
# ----------------------------
# Find the Fortran 77 compiler.  Must be AC_DEFUN'd to be
# AC_REQUIRE'able.
AC_DEFUN([AC_LANG_COMPILER(Fortran 77)],
[AC_REQUIRE([AC_PROG_F77])])

# AC_LANG_COMPILER(Fortran)
# ----------------------------
# Find the Fortran compiler.  Must be AC_DEFUN'd to be
# AC_REQUIRE'able.
AC_DEFUN([AC_LANG_COMPILER(Fortran)],
[AC_REQUIRE([AC_PROG_FC])])


# ac_cv_prog_g77
# --------------
# We used to name the cache variable this way.
AU_DEFUN([ac_cv_prog_g77],
[ac_cv_f77_compiler_gnu])


# _AC_FC_DIALECT_YEAR([DIALECT])
# ------------------------------
# Given a Fortran DIALECT, which is Fortran [YY]YY or simply [YY]YY,
# convert to a 4-digit year.  The dialect must be one of Fortran 77,
# 90, 95, or 2000, currently.  If DIALECT is simply Fortran or the
# empty string, returns the empty string.
AC_DEFUN([_AC_FC_DIALECT_YEAR],
[m4_case(m4_bpatsubsts(m4_tolower([$1]), [fortran],[], [ *],[]),
	 [77],[1977], [1977],[1977],
	 [90],[1990], [1990],[1990],
	 [95],[1995], [1995],[1995],
	 [2000],[2000],
	 [],[],
	 [m4_fatal([unknown Fortran dialect])])])


# _AC_PROG_FC([DIALECT], [COMPILERS...])
# --------------------------------------
# DIALECT is a Fortran dialect, given by Fortran [YY]YY or simply [YY]YY,
# and must be one of those supported by _AC_FC_DIALECT_YEAR
#
# If DIALECT is supplied, then we search for compilers of that dialect
# first, and then later dialects.  Otherwise, we search for compilers
# of the newest dialect first, and then earlier dialects in increasing age.
# This search order is necessarily imperfect because the dialect cannot
# always be inferred from the compiler name.
#
# Known compilers:
#  f77/f90/f95: generic compiler names
#  g77: GNU Fortran 77 compiler
#  gfortran: GNU Fortran 95+ compiler (released in gcc 4.0)
#  g95: original gcc-based f95 compiler (gfortran is a fork)
#  ftn: native Fortran 95 compiler on Cray X1
#  cf77: native F77 compiler under older Crays (prefer over fort77)
#  fort77: native F77 compiler under HP-UX (and some older Crays)
#  frt: Fujitsu F77 compiler
#  pgf77/pgf90/pghpf/pgf95: Portland Group F77/F90/F95 compilers
#  xlf/xlf90/xlf95: IBM (AIX) F77/F90/F95 compilers
#    Prefer xlf9x to the generic names because they do not reject file
#    with extension `.f'.
#  lf95: Lahey-Fujitsu F95 compiler
#  fl32: Microsoft Fortran 77 "PowerStation" compiler
#  af77: Apogee F77 compiler for Intergraph hardware running CLIX
#  epcf90: "Edinburgh Portable Compiler" F90
#  fort: Compaq (now HP) Fortran 90/95 compiler for Tru64 and Linux/Alpha
#  ifort, previously ifc: Intel Fortran 95 compiler for Linux/x86
#  efc: Intel Fortran 95 compiler for IA64
m4_define([_AC_F95_FC], [gfortran g95 xlf95 f95 fort ifort ifc efc pgf95 lf95 ftn])
m4_define([_AC_F90_FC], [xlf90 f90 pgf90 pghpf epcf90])
m4_define([_AC_F77_FC], [g77 xlf f77 frt pgf77 cf77 fort77 fl32 af77])
AC_DEFUN([_AC_PROG_FC],
[_AC_FORTRAN_ASSERT()dnl
AC_CHECK_TOOLS([]_AC_FC[],
      m4_default([$2],
	m4_case(_AC_FC_DIALECT_YEAR([$1]),
		[1995], [_AC_F95_FC],
		[1990], [_AC_F90_FC _AC_F95_FC],
		[1977], [_AC_F77_FC _AC_F90_FC _AC_F95_FC],
		[_AC_F95_FC _AC_F90_FC _AC_F77_FC])))

# Provide some information about the compiler.
_AS_ECHO_LOG([checking for _AC_LANG compiler version])
set X $ac_compile
ac_compiler=$[2]
for ac_option in --version -v -V -qversion; do
  _AC_DO_LIMIT([$ac_compiler $ac_option >&AS_MESSAGE_LOG_FD])
done
rm -f a.out

m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
m4_expand_once([_AC_COMPILER_OBJEXT])[]dnl
# If we don't use `.F' as extension, the preprocessor is not run on the
# input file.  (Note that this only needs to work for GNU compilers.)
ac_save_ext=$ac_ext
ac_ext=F
_AC_LANG_COMPILER_GNU
ac_ext=$ac_save_ext
_AC_PROG_FC_G
])# _AC_PROG_FC


# AC_PROG_F77([COMPILERS...])
# ---------------------------
# COMPILERS is a space separated list of Fortran 77 compilers to search
# for.  See also _AC_PROG_FC.
AC_DEFUN([AC_PROG_F77],
[AC_LANG_PUSH(Fortran 77)dnl
AC_ARG_VAR([F77],    [Fortran 77 compiler command])dnl
AC_ARG_VAR([FFLAGS], [Fortran 77 compiler flags])dnl
_AC_ARG_VAR_LDFLAGS()dnl
_AC_ARG_VAR_LIBS()dnl
_AC_PROG_FC([Fortran 77], [$1])
if test $ac_compiler_gnu = yes; then
  G77=yes
else
  G77=
fi
AC_LANG_POP(Fortran 77)dnl
])# AC_PROG_F77


# AC_PROG_FC([COMPILERS...], [DIALECT])
# -------------------------------------
# COMPILERS is a space separated list of Fortran 77 compilers to search
# for, and [DIALECT] is an optional dialect.  See also _AC_PROG_FC.
AC_DEFUN([AC_PROG_FC],
[AC_LANG_PUSH(Fortran)dnl
AC_ARG_VAR([FC],    [Fortran compiler command])dnl
AC_ARG_VAR([FCFLAGS], [Fortran compiler flags])dnl
_AC_ARG_VAR_LDFLAGS()dnl
_AC_ARG_VAR_LIBS()dnl
_AC_PROG_FC([$2], [$1])
AC_LANG_POP(Fortran)dnl
])# AC_PROG_FC


# _AC_PROG_FC_G
# -------------
# Check whether -g works, even if F[C]FLAGS is set, in case the package
# plays around with F[C]FLAGS (such as to build both debugging and normal
# versions of a library), tasteless as that idea is.
m4_define([_AC_PROG_FC_G],
[_AC_FORTRAN_ASSERT()dnl
ac_test_[]_AC_LANG_PREFIX[]FLAGS=${[]_AC_LANG_PREFIX[]FLAGS+set}
ac_save_[]_AC_LANG_PREFIX[]FLAGS=$[]_AC_LANG_PREFIX[]FLAGS
_AC_LANG_PREFIX[]FLAGS=
AC_CACHE_CHECK(whether $[]_AC_FC[] accepts -g, ac_cv_prog_[]_AC_LANG_ABBREV[]_g,
[_AC_LANG_PREFIX[]FLAGS=-g
_AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
[ac_cv_prog_[]_AC_LANG_ABBREV[]_g=yes],
[ac_cv_prog_[]_AC_LANG_ABBREV[]_g=no])
])
if test "$ac_test_[]_AC_LANG_PREFIX[]FLAGS" = set; then
  _AC_LANG_PREFIX[]FLAGS=$ac_save_[]_AC_LANG_PREFIX[]FLAGS
elif test $ac_cv_prog_[]_AC_LANG_ABBREV[]_g = yes; then
  if test "x$ac_cv_[]_AC_LANG_ABBREV[]_compiler_gnu" = xyes; then
    _AC_LANG_PREFIX[]FLAGS="-g -O2"
  else
    _AC_LANG_PREFIX[]FLAGS="-g"
  fi
else
  if test "x$ac_cv_[]_AC_LANG_ABBREV[]_compiler_gnu" = xyes; then
    _AC_LANG_PREFIX[]FLAGS="-O2"
  else
    _AC_LANG_PREFIX[]FLAGS=
  fi
fi[]dnl
])# _AC_PROG_FC_G


# _AC_PROG_FC_C_O
# ---------------
# Test if the Fortran compiler accepts the options `-c' and `-o'
# simultaneously, and define `[F77/FC]_NO_MINUS_C_MINUS_O' if it does not.
#
# The usefulness of this macro is questionable, as I can't really see
# why anyone would use it.  The only reason I include it is for
# completeness, since a similar test exists for the C compiler.
#
# FIXME: it seems like we could merge the C/C++/Fortran versions of this.
AC_DEFUN([_AC_PROG_FC_C_O],
[_AC_FORTRAN_ASSERT()dnl
AC_CACHE_CHECK([whether $[]_AC_FC[] understands -c and -o together],
	       [ac_cv_prog_[]_AC_LANG_ABBREV[]_c_o],
[AC_LANG_CONFTEST([AC_LANG_PROGRAM([])])
# We test twice because some compilers refuse to overwrite an existing
# `.o' file with `-o', although they will create one.
ac_try='$[]_AC_FC[] $[]_AC_LANG_PREFIX[]FLAGS -c conftest.$ac_ext -o conftest2.$ac_objext >&AS_MESSAGE_LOG_FD'
rm -f conftest2.*
if _AC_DO_VAR(ac_try) &&
     test -f conftest2.$ac_objext &&
     _AC_DO_VAR(ac_try); then
  ac_cv_prog_[]_AC_LANG_ABBREV[]_c_o=yes
else
  ac_cv_prog_[]_AC_LANG_ABBREV[]_c_o=no
fi
rm -f conftest*])
if test $ac_cv_prog_[]_AC_LANG_ABBREV[]_c_o = no; then
  AC_DEFINE([]_AC_FC[]_NO_MINUS_C_MINUS_O, 1,
	    [Define to 1 if your Fortran compiler doesn't accept
	     -c and -o together.])
fi
])# _AC_PROG_FC_C_O


# AC_PROG_F77_C_O
# ---------------
AC_DEFUN([AC_PROG_F77_C_O],
[AC_REQUIRE([AC_PROG_F77])dnl
AC_LANG_PUSH(Fortran 77)dnl
_AC_PROG_FC_C_O
AC_LANG_POP(Fortran 77)dnl
])# AC_PROG_F77_C_O


# AC_PROG_FC_C_O
# ---------------
AC_DEFUN([AC_PROG_FC_C_O],
[AC_REQUIRE([AC_PROG_FC])dnl
AC_LANG_PUSH(Fortran)dnl
_AC_PROG_FC_C_O
AC_LANG_POP(Fortran)dnl
])# AC_PROG_FC_C_O


## ------------------------------- ##
## 4. Compilers' characteristics.  ##
## ------------------------------- ##


# _AC_PROG_FC_V_OUTPUT([FLAG = $ac_cv_prog_{f77/fc}_v])
# -------------------------------------------------
# Link a trivial Fortran program, compiling with a verbose output FLAG
# (whose default value, $ac_cv_prog_{f77/fc}_v, is computed by
# _AC_PROG_FC_V), and return the output in $ac_{f77/fc}_v_output.  This
# output is processed in the way expected by _AC_FC_LIBRARY_LDFLAGS,
# so that any link flags that are echoed by the compiler appear as
# space-separated items.
AC_DEFUN([_AC_PROG_FC_V_OUTPUT],
[_AC_FORTRAN_ASSERT()dnl
AC_LANG_CONFTEST([AC_LANG_PROGRAM([])])

# Compile and link our simple test program by passing a flag (argument
# 1 to this macro) to the Fortran compiler in order to get
# "verbose" output that we can then parse for the Fortran linker
# flags.
ac_save_[]_AC_LANG_PREFIX[]FLAGS=$[]_AC_LANG_PREFIX[]FLAGS
_AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS m4_default([$1], [$ac_cv_prog_[]_AC_LANG_ABBREV[]_v])"
eval "set x $ac_link"
shift
_AS_ECHO_LOG([$[*]])
# gfortran 4.3 outputs lines setting COLLECT_GCC_OPTIONS, COMPILER_PATH,
# LIBRARY_PATH; skip all such settings.
ac_[]_AC_LANG_ABBREV[]_v_output=`eval $ac_link AS_MESSAGE_LOG_FD>&1 2>&1 |
  grep -v 'Driving:' | grep -v "^[[_$as_cr_Letters]][[_$as_cr_alnum]]*="`
AS_ECHO(["$ac_[]_AC_LANG_ABBREV[]_v_output"]) >&AS_MESSAGE_LOG_FD
_AC_LANG_PREFIX[]FLAGS=$ac_save_[]_AC_LANG_PREFIX[]FLAGS

rm -rf conftest*

# On HP/UX there is a line like: "LPATH is: /foo:/bar:/baz" where
# /foo, /bar, and /baz are search directories for the Fortran linker.
# Here, we change these into -L/foo -L/bar -L/baz (and put it first):
ac_[]_AC_LANG_ABBREV[]_v_output="`echo $ac_[]_AC_LANG_ABBREV[]_v_output |
	grep 'LPATH is:' |
	sed 's|.*LPATH is\(: *[[^ ]]*\).*|\1|;s|: */| -L/|g'` $ac_[]_AC_LANG_ABBREV[]_v_output"

# FIXME: we keep getting bitten by quoted arguments; a more general fix
#        that detects unbalanced quotes in FLIBS should be implemented
#        and (ugh) tested at some point.
case $ac_[]_AC_LANG_ABBREV[]_v_output in
  # If we are using xlf then replace all the commas with spaces.
  *xlfentry*)
    ac_[]_AC_LANG_ABBREV[]_v_output=`echo $ac_[]_AC_LANG_ABBREV[]_v_output | sed 's/,/ /g'` ;;

  # With Intel ifc, ignore the quoted -mGLOB_options_string stuff (quoted
  # $LIBS confuse us, and the libraries appear later in the output anyway).
  *mGLOB_options_string*)
    ac_[]_AC_LANG_ABBREV[]_v_output=`echo $ac_[]_AC_LANG_ABBREV[]_v_output | sed 's/"-mGLOB[[^"]]*"/ /g'` ;;

  # Portland Group compiler has singly- or doubly-quoted -cmdline argument
  # Singly-quoted arguments were reported for versions 5.2-4 and 6.0-4.
  # Doubly-quoted arguments were reported for "PGF90/x86 Linux/x86 5.0-2".
  *-cmdline\ * | *-ignore\ * | *-def\ *)
    ac_[]_AC_LANG_ABBREV[]_v_output=`echo $ac_[]_AC_LANG_ABBREV[]_v_output | sed "\
	s/-cmdline  *'[[^']]*'/ /g; s/-cmdline  *\"[[^\"]]*\"/ /g
	s/-ignore  *'[[^']]*'/ /g; s/-ignore  *\"[[^\"]]*\"/ /g
	s/-def  *'[[^']]*'/ /g; s/-def  *\"[[^\"]]*\"/ /g"` ;;

  # If we are using Cray Fortran then delete quotes.
  *cft90*)
    ac_[]_AC_LANG_ABBREV[]_v_output=`echo $ac_[]_AC_LANG_ABBREV[]_v_output | sed 's/"//g'` ;;
esac

])# _AC_PROG_FC_V_OUTPUT


# _AC_PROG_FC_V
# --------------
#
# Determine the flag that causes the Fortran compiler to print
# information of library and object files (normally -v)
# Needed for _AC_FC_LIBRARY_FLAGS
# Some compilers don't accept -v (Lahey: -verbose, xlf: -V, Fujitsu: -###)
AC_DEFUN([_AC_PROG_FC_V],
[_AC_FORTRAN_ASSERT()dnl
AC_CACHE_CHECK([how to get verbose linking output from $[]_AC_FC[]],
		[ac_cv_prog_[]_AC_LANG_ABBREV[]_v],
[AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
[ac_cv_prog_[]_AC_LANG_ABBREV[]_v=
# Try some options frequently used verbose output
for ac_verb in -v -verbose --verbose -V -\#\#\#; do
  _AC_PROG_FC_V_OUTPUT($ac_verb)
  # look for -l* and *.a constructs in the output
  for ac_arg in $ac_[]_AC_LANG_ABBREV[]_v_output; do
     case $ac_arg in
	[[\\/]]*.a | ?:[[\\/]]*.a | -[[lLRu]]*)
	  ac_cv_prog_[]_AC_LANG_ABBREV[]_v=$ac_verb
	  break 2 ;;
     esac
  done
done
if test -z "$ac_cv_prog_[]_AC_LANG_ABBREV[]_v"; then
   AC_MSG_WARN([cannot determine how to obtain linking information from $[]_AC_FC[]])
fi],
		  [AC_MSG_WARN([compilation failed])])
])])# _AC_PROG_FC_V


# _AC_FC_LIBRARY_LDFLAGS
# ----------------------
#
# Determine the linker flags (e.g. "-L" and "-l") for the Fortran
# intrinsic and runtime libraries that are required to successfully
# link a Fortran program or shared library.  The output variable
# FLIBS/FCLIBS is set to these flags.
#
# This macro is intended to be used in those situations when it is
# necessary to mix, e.g. C++ and Fortran, source code into a single
# program or shared library.
#
# For example, if object files from a C++ and Fortran compiler must
# be linked together, then the C++ compiler/linker must be used for
# linking (since special C++-ish things need to happen at link time
# like calling global constructors, instantiating templates, enabling
# exception support, etc.).
#
# However, the Fortran intrinsic and runtime libraries must be
# linked in as well, but the C++ compiler/linker doesn't know how to
# add these Fortran libraries.  Hence, the macro
# "AC_F77_LIBRARY_LDFLAGS" was created to determine these Fortran
# libraries.
#
# This macro was packaged in its current form by Matthew D. Langston.
# However, nearly all of this macro came from the "OCTAVE_FLIBS" macro
# in "octave-2.0.13/aclocal.m4", and full credit should go to John
# W. Eaton for writing this extremely useful macro.  Thank you John.
AC_DEFUN([_AC_FC_LIBRARY_LDFLAGS],
[_AC_FORTRAN_ASSERT()dnl
_AC_PROG_FC_V
AC_CACHE_CHECK([for _AC_LANG libraries of $[]_AC_FC[]], ac_cv_[]_AC_LANG_ABBREV[]_libs,
[if test "x$[]_AC_LANG_PREFIX[]LIBS" != "x"; then
  ac_cv_[]_AC_LANG_ABBREV[]_libs="$[]_AC_LANG_PREFIX[]LIBS" # Let the user override the test.
else

_AC_PROG_FC_V_OUTPUT

ac_cv_[]_AC_LANG_ABBREV[]_libs=

# Save positional arguments (if any)
ac_save_positional="$[@]"

set X $ac_[]_AC_LANG_ABBREV[]_v_output
while test $[@%:@] != 1; do
  shift
  ac_arg=$[1]
  case $ac_arg in
	[[\\/]]*.a | ?:[[\\/]]*.a)
	  _AC_LIST_MEMBER_IF($ac_arg, $ac_cv_[]_AC_LANG_ABBREV[]_libs, ,
	      ac_cv_[]_AC_LANG_ABBREV[]_libs="$ac_cv_[]_AC_LANG_ABBREV[]_libs $ac_arg")
	  ;;
	-bI:*)
	  _AC_LIST_MEMBER_IF($ac_arg, $ac_cv_[]_AC_LANG_ABBREV[]_libs, ,
	     [_AC_LINKER_OPTION([$ac_arg], ac_cv_[]_AC_LANG_ABBREV[]_libs)])
	  ;;
	  # Ignore these flags.
	-lang* | -lcrt*.o | -lc | -lgcc* | -lSystem | -libmil | -little \
	  |-LANG:=* | -LIST:* | -LNO:*)
	  ;;
	-lkernel32)
	  test x"$CYGWIN" != xyes && ac_cv_[]_AC_LANG_ABBREV[]_libs="$ac_cv_[]_AC_LANG_ABBREV[]_libs $ac_arg"
	  ;;
	-[[LRuYz]])
	  # These flags, when seen by themselves, take an argument.
	  # We remove the space between option and argument and re-iterate
	  # unless we find an empty arg or a new option (starting with -)
	  case $[2] in
	     "" | -*);;
	     *)
		ac_arg="$ac_arg$[2]"
		shift; shift
		set X $ac_arg "$[@]"
		;;
	  esac
	  ;;
	-YP,*)
	  for ac_j in `AS_ECHO(["$ac_arg"]) | sed -e 's/-YP,/-L/;s/:/ -L/g'`; do
	    _AC_LIST_MEMBER_IF($ac_j, $ac_cv_[]_AC_LANG_ABBREV[]_libs, ,
			       [ac_arg="$ac_arg $ac_j"
			       ac_cv_[]_AC_LANG_ABBREV[]_libs="$ac_cv_[]_AC_LANG_ABBREV[]_libs $ac_j"])
	  done
	  ;;
	-[[lLR]]*)
	  _AC_LIST_MEMBER_IF($ac_arg, $ac_cv_[]_AC_LANG_ABBREV[]_libs, ,
			     ac_cv_[]_AC_LANG_ABBREV[]_libs="$ac_cv_[]_AC_LANG_ABBREV[]_libs $ac_arg")
	  ;;
	-zallextract*| -zdefaultextract)
	  ac_cv_[]_AC_LANG_ABBREV[]_libs="$ac_cv_[]_AC_LANG_ABBREV[]_libs $ac_arg"
	  ;;
	  # Ignore everything else.
  esac
done
# restore positional arguments
set X $ac_save_positional; shift

# We only consider "LD_RUN_PATH" on Solaris systems.  If this is seen,
# then we insist that the "run path" must be an absolute path (i.e. it
# must begin with a "/").
case `(uname -sr) 2>/dev/null` in
   "SunOS 5"*)
      ac_ld_run_path=`AS_ECHO(["$ac_[]_AC_LANG_ABBREV[]_v_output"]) |
			sed -n 's,^.*LD_RUN_PATH *= *\(/[[^ ]]*\).*$,-R\1,p'`
      test "x$ac_ld_run_path" != x &&
	_AC_LINKER_OPTION([$ac_ld_run_path], ac_cv_[]_AC_LANG_ABBREV[]_libs)
      ;;
esac
fi # test "x$[]_AC_LANG_PREFIX[]LIBS" = "x"
])
[]_AC_LANG_PREFIX[]LIBS="$ac_cv_[]_AC_LANG_ABBREV[]_libs"
AC_SUBST([]_AC_LANG_PREFIX[]LIBS)
])# _AC_FC_LIBRARY_LDFLAGS


# AC_F77_LIBRARY_LDFLAGS
# ----------------------
AC_DEFUN([AC_F77_LIBRARY_LDFLAGS],
[AC_REQUIRE([AC_PROG_F77])dnl
AC_LANG_PUSH(Fortran 77)dnl
_AC_FC_LIBRARY_LDFLAGS
AC_LANG_POP(Fortran 77)dnl
])# AC_F77_LIBRARY_LDFLAGS


# AC_FC_LIBRARY_LDFLAGS
# ----------------------
AC_DEFUN([AC_FC_LIBRARY_LDFLAGS],
[AC_REQUIRE([AC_PROG_FC])dnl
AC_LANG_PUSH(Fortran)dnl
_AC_FC_LIBRARY_LDFLAGS
AC_LANG_POP(Fortran)dnl
])# AC_FC_LIBRARY_LDFLAGS


# _AC_FC_DUMMY_MAIN([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
# -----------------------------------------------------------
#
# Detect name of dummy main routine required by the Fortran libraries,
# (if any) and define {F77,FC}_DUMMY_MAIN to this name (which should be
# used for a dummy declaration, if it is defined).  On some systems,
# linking a C program to the Fortran library does not work unless you
# supply a dummy function called something like MAIN__.
#
# Execute ACTION-IF-NOT-FOUND if no way of successfully linking a C
# program with the {F77,FC} libs is found; default to exiting with an error
# message.  Execute ACTION-IF-FOUND if a dummy routine name is needed
# and found or if it is not needed (default to defining {F77,FC}_DUMMY_MAIN
# when needed).
#
# What is technically happening is that the Fortran libraries provide
# their own main() function, which usually initializes Fortran I/O and
# similar stuff, and then calls MAIN__, which is the entry point of
# your program.  Usually, a C program will override this with its own
# main() routine, but the linker sometimes complain if you don't
# provide a dummy (never-called) MAIN__ routine anyway.
#
# Of course, programs that want to allow Fortran subroutines to do
# I/O, etcetera, should call their main routine MAIN__() (or whatever)
# instead of main().  A separate autoconf test (_AC_FC_MAIN) checks
# for the routine to use in this case (since the semantics of the test
# are slightly different).  To link to e.g. purely numerical
# libraries, this is normally not necessary, however, and most C/C++
# programs are reluctant to turn over so much control to Fortran.  =)
#
# The name variants we check for are (in order):
#   MAIN__ (g77, MAIN__ required on some systems; IRIX, MAIN__ optional)
#   MAIN_, __main (SunOS)
#   MAIN _MAIN __MAIN main_ main__ _main (we follow DDD and try these too)
AC_DEFUN([_AC_FC_DUMMY_MAIN],
[_AC_FORTRAN_ASSERT()dnl
m4_define(_AC_LANG_PROGRAM_C_[]_AC_FC[]_HOOKS,
[#ifdef ]_AC_FC[_DUMMY_MAIN
]AC_LANG_CASE([Fortran], [#ifndef FC_DUMMY_MAIN_EQ_F77])
[#  ifdef __cplusplus
     extern "C"
#  endif
   int ]_AC_FC[_DUMMY_MAIN() { return 1; }
]AC_LANG_CASE([Fortran], [#endif])
[#endif
])
AC_CACHE_CHECK([for dummy main to link with _AC_LANG libraries],
	       ac_cv_[]_AC_LANG_ABBREV[]_dummy_main,
[ac_[]_AC_LANG_ABBREV[]_dm_save_LIBS=$LIBS
 LIBS="$LIBS $[]_AC_LANG_PREFIX[]LIBS"
 ac_fortran_dm_var=[]_AC_FC[]_DUMMY_MAIN
 AC_LANG_PUSH(C)dnl

 # First, try linking without a dummy main:
 AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
		[ac_cv_fortran_dummy_main=none],
		[ac_cv_fortran_dummy_main=unknown])

 if test $ac_cv_fortran_dummy_main = unknown; then
   for ac_func in MAIN__ MAIN_ __main MAIN _MAIN __MAIN main_ main__ _main; do
     AC_LINK_IFELSE([AC_LANG_PROGRAM([[@%:@define $ac_fortran_dm_var $ac_func]])],
		    [ac_cv_fortran_dummy_main=$ac_func; break])
   done
 fi
 AC_LANG_POP(C)dnl
 ac_cv_[]_AC_LANG_ABBREV[]_dummy_main=$ac_cv_fortran_dummy_main
 rm -rf conftest*
 LIBS=$ac_[]_AC_LANG_ABBREV[]_dm_save_LIBS
])
[]_AC_FC[]_DUMMY_MAIN=$ac_cv_[]_AC_LANG_ABBREV[]_dummy_main
AS_IF([test "$[]_AC_FC[]_DUMMY_MAIN" != unknown],
      [m4_default([$1],
[if test $[]_AC_FC[]_DUMMY_MAIN != none; then
  AC_DEFINE_UNQUOTED([]_AC_FC[]_DUMMY_MAIN, $[]_AC_FC[]_DUMMY_MAIN,
		     [Define to dummy `main' function (if any) required to
		      link to the Fortran libraries.])
  if test "x$ac_cv_fc_dummy_main" = "x$ac_cv_f77_dummy_main"; then
	AC_DEFINE([FC_DUMMY_MAIN_EQ_F77], 1,
		  [Define if F77 and FC dummy `main' functions are identical.])
  fi
fi])],
      [m4_default([$2],
	    [AC_MSG_FAILURE([linking to Fortran libraries from C fails])])])
])# _AC_FC_DUMMY_MAIN


# AC_F77_DUMMY_MAIN
# ----------------------
AC_DEFUN([AC_F77_DUMMY_MAIN],
[AC_REQUIRE([AC_F77_LIBRARY_LDFLAGS])dnl
AC_LANG_PUSH(Fortran 77)dnl
_AC_FC_DUMMY_MAIN($@)
AC_LANG_POP(Fortran 77)dnl
])# AC_F77_DUMMY_MAIN


# AC_FC_DUMMY_MAIN
# ----------------------
AC_DEFUN([AC_FC_DUMMY_MAIN],
[AC_REQUIRE([AC_FC_LIBRARY_LDFLAGS])dnl
AC_LANG_PUSH(Fortran)dnl
_AC_FC_DUMMY_MAIN($@)
AC_LANG_POP(Fortran)dnl
])# AC_FC_DUMMY_MAIN


# _AC_FC_MAIN
# -----------
# Define {F77,FC}_MAIN to name of alternate main() function for use with
# the Fortran libraries.  (Typically, the libraries may define their
# own main() to initialize I/O, etcetera, that then call your own
# routine called MAIN__ or whatever.)  See _AC_FC_DUMMY_MAIN, above.
# If no such alternate name is found, just define {F77,FC}_MAIN to main.
#
AC_DEFUN([_AC_FC_MAIN],
[_AC_FORTRAN_ASSERT()dnl
AC_CACHE_CHECK([for alternate main to link with _AC_LANG libraries],
	       ac_cv_[]_AC_LANG_ABBREV[]_main,
[ac_[]_AC_LANG_ABBREV[]_m_save_LIBS=$LIBS
 LIBS="$LIBS $[]_AC_LANG_PREFIX[]LIBS"
 ac_fortran_dm_var=[]_AC_FC[]_DUMMY_MAIN
 AC_LANG_PUSH(C)dnl
 ac_cv_fortran_main="main" # default entry point name
 for ac_func in MAIN__ MAIN_ __main MAIN _MAIN __MAIN main_ main__ _main; do
   AC_LINK_IFELSE([AC_LANG_PROGRAM([@%:@ifdef FC_DUMMY_MAIN_EQ_F77
@%:@  undef F77_DUMMY_MAIN
@%:@  undef FC_DUMMY_MAIN
@%:@else
@%:@  undef $ac_fortran_dm_var
@%:@endif
@%:@define main $ac_func])],
		  [ac_cv_fortran_main=$ac_func; break])
 done
 AC_LANG_POP(C)dnl
 ac_cv_[]_AC_LANG_ABBREV[]_main=$ac_cv_fortran_main
 rm -rf conftest*
 LIBS=$ac_[]_AC_LANG_ABBREV[]_m_save_LIBS
])
AC_DEFINE_UNQUOTED([]_AC_FC[]_MAIN, $ac_cv_[]_AC_LANG_ABBREV[]_main,
		   [Define to alternate name for `main' routine that is
		    called from a `main' in the Fortran libraries.])
])# _AC_FC_MAIN


# AC_F77_MAIN
# -----------
AC_DEFUN([AC_F77_MAIN],
[AC_REQUIRE([AC_F77_LIBRARY_LDFLAGS])dnl
AC_LANG_PUSH(Fortran 77)dnl
_AC_FC_MAIN
AC_LANG_POP(Fortran 77)dnl
])# AC_F77_MAIN


# AC_FC_MAIN
# ----------
AC_DEFUN([AC_FC_MAIN],
[AC_REQUIRE([AC_FC_LIBRARY_LDFLAGS])dnl
AC_LANG_PUSH(Fortran)dnl
_AC_FC_MAIN
AC_LANG_POP(Fortran)dnl
])# AC_FC_MAIN


# __AC_FC_NAME_MANGLING
# ---------------------
# Test for the name mangling scheme used by the Fortran compiler.
#
# Sets ac_cv_{f77,fc}_mangling. The value contains three fields, separated
# by commas:
#
# lower case / upper case:
#    case translation of the Fortran symbols
# underscore / no underscore:
#    whether the compiler appends "_" to symbol names
# extra underscore / no extra underscore:
#    whether the compiler appends an extra "_" to symbol names already
#    containing at least one underscore
#
AC_DEFUN([__AC_FC_NAME_MANGLING],
[_AC_FORTRAN_ASSERT()dnl
AC_CACHE_CHECK([for _AC_LANG name-mangling scheme],
	       ac_cv_[]_AC_LANG_ABBREV[]_mangling,
[AC_COMPILE_IFELSE(
[      subroutine foobar()
      return
      end
      subroutine foo_bar()
      return
      end],
[mv conftest.$ac_objext cfortran_test.$ac_objext

  ac_save_LIBS=$LIBS
  LIBS="cfortran_test.$ac_objext $LIBS $[]_AC_LANG_PREFIX[]LIBS"

  AC_LANG_PUSH(C)dnl
  ac_success=no
  for ac_foobar in foobar FOOBAR; do
    for ac_underscore in "" "_"; do
      ac_func="$ac_foobar$ac_underscore"
      AC_LINK_IFELSE([AC_LANG_CALL([], [$ac_func])],
		     [ac_success=yes; break 2])
    done
  done
  AC_LANG_POP(C)dnl

  if test "$ac_success" = "yes"; then
     case $ac_foobar in
	foobar)
	   ac_case=lower
	   ac_foo_bar=foo_bar
	   ;;
	FOOBAR)
	   ac_case=upper
	   ac_foo_bar=FOO_BAR
	   ;;
     esac

     AC_LANG_PUSH(C)dnl
     ac_success_extra=no
     for ac_extra in "" "_"; do
	ac_func="$ac_foo_bar$ac_underscore$ac_extra"
	AC_LINK_IFELSE([AC_LANG_CALL([], [$ac_func])],
		       [ac_success_extra=yes; break])
     done
     AC_LANG_POP(C)dnl

     if test "$ac_success_extra" = "yes"; then
	ac_cv_[]_AC_LANG_ABBREV[]_mangling="$ac_case case"
	if test -z "$ac_underscore"; then
	   ac_cv_[]_AC_LANG_ABBREV[]_mangling="$ac_cv_[]_AC_LANG_ABBREV[]_mangling, no underscore"
	else
	   ac_cv_[]_AC_LANG_ABBREV[]_mangling="$ac_cv_[]_AC_LANG_ABBREV[]_mangling, underscore"
	fi
	if test -z "$ac_extra"; then
	   ac_cv_[]_AC_LANG_ABBREV[]_mangling="$ac_cv_[]_AC_LANG_ABBREV[]_mangling, no extra underscore"
	else
	   ac_cv_[]_AC_LANG_ABBREV[]_mangling="$ac_cv_[]_AC_LANG_ABBREV[]_mangling, extra underscore"
	fi
      else
	ac_cv_[]_AC_LANG_ABBREV[]_mangling="unknown"
      fi
  else
     ac_cv_[]_AC_LANG_ABBREV[]_mangling="unknown"
  fi

  LIBS=$ac_save_LIBS
  rm -rf conftest*
  rm -f cfortran_test*],
  [AC_MSG_FAILURE([cannot compile a simple Fortran program])])
])
])# __AC_FC_NAME_MANGLING

# The replacement is empty.
AU_DEFUN([AC_F77_NAME_MANGLING], [])


# _AC_F77_NAME_MANGLING
# ----------------------
AC_DEFUN([_AC_F77_NAME_MANGLING],
[AC_REQUIRE([AC_F77_LIBRARY_LDFLAGS])dnl
AC_REQUIRE([AC_F77_DUMMY_MAIN])dnl
AC_LANG_PUSH(Fortran 77)dnl
__AC_FC_NAME_MANGLING
AC_LANG_POP(Fortran 77)dnl
])# _AC_F77_NAME_MANGLING


# _AC_FC_NAME_MANGLING
# ----------------------
AC_DEFUN([_AC_FC_NAME_MANGLING],
[AC_REQUIRE([AC_FC_LIBRARY_LDFLAGS])dnl
AC_REQUIRE([AC_FC_DUMMY_MAIN])dnl
AC_LANG_PUSH(Fortran)dnl
__AC_FC_NAME_MANGLING
AC_LANG_POP(Fortran)dnl
])# _AC_FC_NAME_MANGLING


# _AC_FC_WRAPPERS
# ---------------
# Defines C macros {F77,FC}_FUNC(name,NAME) and {F77,FC}_FUNC_(name,NAME) to
# properly mangle the names of C identifiers, and C identifiers with
# underscores, respectively, so that they match the name mangling
# scheme used by the Fortran compiler.
AC_DEFUN([_AC_FC_WRAPPERS],
[_AC_FORTRAN_ASSERT()dnl
AH_TEMPLATE(_AC_FC[_FUNC],
    [Define to a macro mangling the given C identifier (in lower and upper
     case), which must not contain underscores, for linking with Fortran.])dnl
AH_TEMPLATE(_AC_FC[_FUNC_],
    [As ]_AC_FC[_FUNC, but for C identifiers containing underscores.])dnl
case $ac_cv_[]_AC_LANG_ABBREV[]_mangling in
  "lower case, no underscore, no extra underscore")
	  AC_DEFINE(_AC_FC[_FUNC(name,NAME)],  [name])
	  AC_DEFINE(_AC_FC[_FUNC_(name,NAME)], [name]) ;;
  "lower case, no underscore, extra underscore")
	  AC_DEFINE(_AC_FC[_FUNC(name,NAME)],  [name])
	  AC_DEFINE(_AC_FC[_FUNC_(name,NAME)], [name [##] _]) ;;
  "lower case, underscore, no extra underscore")
	  AC_DEFINE(_AC_FC[_FUNC(name,NAME)],  [name [##] _])
	  AC_DEFINE(_AC_FC[_FUNC_(name,NAME)], [name [##] _]) ;;
  "lower case, underscore, extra underscore")
	  AC_DEFINE(_AC_FC[_FUNC(name,NAME)],  [name [##] _])
	  AC_DEFINE(_AC_FC[_FUNC_(name,NAME)], [name [##] __]) ;;
  "upper case, no underscore, no extra underscore")
	  AC_DEFINE(_AC_FC[_FUNC(name,NAME)],  [NAME])
	  AC_DEFINE(_AC_FC[_FUNC_(name,NAME)], [NAME]) ;;
  "upper case, no underscore, extra underscore")
	  AC_DEFINE(_AC_FC[_FUNC(name,NAME)],  [NAME])
	  AC_DEFINE(_AC_FC[_FUNC_(name,NAME)], [NAME [##] _]) ;;
  "upper case, underscore, no extra underscore")
	  AC_DEFINE(_AC_FC[_FUNC(name,NAME)],  [NAME [##] _])
	  AC_DEFINE(_AC_FC[_FUNC_(name,NAME)], [NAME [##] _]) ;;
  "upper case, underscore, extra underscore")
	  AC_DEFINE(_AC_FC[_FUNC(name,NAME)],  [NAME [##] _])
	  AC_DEFINE(_AC_FC[_FUNC_(name,NAME)], [NAME [##] __]) ;;
  *)
	  AC_MSG_WARN([unknown Fortran name-mangling scheme])
	  ;;
esac
])# _AC_FC_WRAPPERS


# AC_F77_WRAPPERS
# ---------------
AC_DEFUN([AC_F77_WRAPPERS],
[AC_REQUIRE([_AC_F77_NAME_MANGLING])dnl
AC_LANG_PUSH(Fortran 77)dnl
_AC_FC_WRAPPERS
AC_LANG_POP(Fortran 77)dnl
])# AC_F77_WRAPPERS


# AC_FC_WRAPPERS
# --------------
AC_DEFUN([AC_FC_WRAPPERS],
[AC_REQUIRE([_AC_FC_NAME_MANGLING])dnl
AC_LANG_PUSH(Fortran)dnl
_AC_FC_WRAPPERS
AC_LANG_POP(Fortran)dnl
])# AC_FC_WRAPPERS


# _AC_FC_FUNC(NAME, [SHELLVAR = NAME])
# ------------------------------------
# For a Fortran subroutine of given NAME, define a shell variable
# $SHELLVAR to the Fortran-mangled name.  If the SHELLVAR
# argument is not supplied, it defaults to NAME.
AC_DEFUN([_AC_FC_FUNC],
[_AC_FORTRAN_ASSERT()dnl
case $ac_cv_[]_AC_LANG_ABBREV[]_mangling in
  upper*) ac_val="m4_toupper([$1])" ;;
  lower*) ac_val="m4_tolower([$1])" ;;
  *)      ac_val="unknown" ;;
esac
case $ac_cv_[]_AC_LANG_ABBREV[]_mangling in *," underscore"*) ac_val="$ac_val"_ ;; esac
m4_if(m4_index([$1],[_]),-1,[],
[case $ac_cv_[]_AC_LANG_ABBREV[]_mangling in *," extra underscore"*) ac_val="$ac_val"_ ;; esac
])
m4_default([$2],[$1])="$ac_val"
])# _AC_FC_FUNC


# AC_F77_FUNC(NAME, [SHELLVAR = NAME])
# ------------------------------------
AC_DEFUN([AC_F77_FUNC],
[AC_REQUIRE([_AC_F77_NAME_MANGLING])dnl
AC_LANG_PUSH(Fortran 77)dnl
_AC_FC_FUNC([$1],[$2])
AC_LANG_POP(Fortran 77)dnl
])# AC_F77_FUNC


# AC_FC_FUNC(NAME, [SHELLVAR = NAME])
# -----------------------------------
AC_DEFUN([AC_FC_FUNC],
[AC_REQUIRE([_AC_FC_NAME_MANGLING])dnl
AC_LANG_PUSH(Fortran)dnl
_AC_FC_FUNC([$1],[$2])
AC_LANG_POP(Fortran)dnl
])# AC_FC_FUNC


# AC_FC_SRCEXT(EXT, [ACTION-IF-SUCCESS], [ACTION-IF-FAILURE])
# -----------------------------------------------------------
# Set the source-code extension used in Fortran (FC) tests to EXT (which
# defaults to f).  Also, look for any necessary additional FCFLAGS needed
# to allow this extension, and store them in the output variable
# FCFLAGS_<EXT> (e.g. FCFLAGS_f90 for EXT=f90).  If successful,
# call ACTION-IF-SUCCESS.  If unable to compile source code with EXT,
# call ACTION-IF-FAILURE, which defaults to failing with an error
# message.
#
# (The flags for the current source-code extension, if any, are stored in
# $ac_fcflags_srcext and used automatically in subsequent autoconf tests.)
#
# For ordinary extensions like f90, etcetera, the modified FCFLAGS
# are currently needed for IBM's xlf* and Intel's ifc (grrr).  Unfortunately,
# xlf* will only take flags to recognize one extension at a time, so if the
# user wants to compile multiple extensions (.f90 and .f95, say), she
# will need to use the FCFLAGS_F90 and FCFLAGS_F95 individually rather
# than just adding them all to FCFLAGS, for example.
#
# Also, for Intel's ifc compiler (which does not accept .f95 by default in
# some versions), the $FCFLAGS_<EXT> variable *must* go immediately before
# the source file on the command line, unlike other $FCFLAGS.  Ugh.
AC_DEFUN([AC_FC_SRCEXT],
[AC_LANG_PUSH(Fortran)dnl
AC_CACHE_CHECK([for Fortran flag to compile .$1 files],
		ac_cv_fc_srcext_$1,
[ac_ext=$1
ac_fcflags_srcext_save=$ac_fcflags_srcext
ac_fcflags_srcext=
ac_cv_fc_srcext_$1=unknown
for ac_flag in none -qsuffix=f=$1 -Tf; do
  test "x$ac_flag" != xnone && ac_fcflags_srcext="$ac_flag"
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM()], [ac_cv_fc_srcext_$1=$ac_flag; break])
done
rm -f conftest.$ac_objext conftest.$1
ac_fcflags_srcext=$ac_fcflags_srcext_save
])
if test "x$ac_cv_fc_srcext_$1" = xunknown; then
  m4_default([$3],[AC_MSG_ERROR([Fortran could not compile .$1 files])])
else
  ac_fc_srcext=$1
  if test "x$ac_cv_fc_srcext_$1" = xnone; then
    ac_fcflags_srcext=""
    FCFLAGS_[]$1[]=""
  else
    ac_fcflags_srcext=$ac_cv_fc_srcext_$1
    FCFLAGS_[]$1[]=$ac_cv_fc_srcext_$1
  fi
  AC_SUBST(FCFLAGS_[]$1)
  $2
fi
AC_LANG_POP(Fortran)dnl
])# AC_FC_SRCEXT


# AC_FC_FREEFORM([ACTION-IF-SUCCESS], [ACTION-IF-FAILURE = FAILURE])
# ------------------------------------------------------------------
# Look for a compiler flag to make the Fortran (FC) compiler accept
# free-format source code, and adds it to FCFLAGS.  Call
# ACTION-IF-SUCCESS (defaults to nothing) if successful (i.e. can
# compile code using new extension) and ACTION-IF-FAILURE (defaults to
# failing with an error message) if not.  (Defined via DEFUN_ONCE to
# prevent flag from being added to FCFLAGS multiple times.)
#
# The known flags are:
#        -ffree-form: GNU g77
#                -FR: Intel compiler (icc, ecc)
#              -free: Compaq compiler (fort)
#             -qfree: IBM compiler (xlf)
# -Mfree, -Mfreeform: Portland Group compiler
#          -freeform: SGI compiler
#            -f free: Absoft Fortran
# We try to test the "more popular" flags first, by some prejudiced
# notion of popularity.
AC_DEFUN_ONCE([AC_FC_FREEFORM],
[AC_LANG_PUSH(Fortran)dnl
AC_CACHE_CHECK([for Fortran flag needed to allow free-form source],
		ac_cv_fc_freeform,
[ac_cv_fc_freeform=unknown
ac_fc_freeform_FCFLAGS_save=$FCFLAGS
for ac_flag in none -ffree-form -FR -free -qfree -Mfree -Mfreeform \
	       -freeform "-f free"
do
  test "x$ac_flag" != xnone && FCFLAGS="$ac_fc_freeform_FCFLAGS_save $ac_flag"
dnl Use @&t@ below to ensure that editors don't turn 8+ spaces into tab.
  AC_COMPILE_IFELSE([
  program freeform
       ! FIXME: how to best confuse non-freeform compilers?
       print *, 'Hello ', &
     @&t@     'world.'
       end],
		    [ac_cv_fc_freeform=$ac_flag; break])
done
rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
FCFLAGS=$ac_fc_freeform_FCFLAGS_save
])
if test "x$ac_cv_fc_freeform" = xunknown; then
  m4_default([$2],
	     [AC_MSG_ERROR([Fortran does not accept free-form source], 77)])
else
  if test "x$ac_cv_fc_freeform" != xnone; then
    FCFLAGS="$FCFLAGS $ac_cv_fc_freeform"
  fi
  $1
fi
AC_LANG_POP(Fortran)dnl
])# AC_FC_FREEFORM