#! /bin/sh

# configuration script

# This file is part of the Zarith library 
# http://forge.ocamlcore.org/projects/zarith .
# It is distributed under LGPL 2 licensing, with static linking exception.
# See the LICENSE file included in the distribution.
#   
# Copyright (c) 2010-2011 Antoine Miné, Abstraction project.
# Abstraction is part of the LIENS (Laboratoire d'Informatique de l'ENS),
# a joint laboratory by:
# CNRS (Centre national de la recherche scientifique, France),
# ENS (École normale supérieure, Paris, France),
# INRIA Rocquencourt (Institut national de recherche en informatique, France).


# options
installdir='auto'
ocamllibdir='auto'
gmp='auto'
perf='no'

ocaml='ocaml'
ocamlc='ocamlc'
ocamlopt='ocamlopt'
ocamlmklib='ocamlmklib'
ocamldep='ocamldep'
ocamldoc='ocamldoc'
ccinc="$CPPFLAGS"
ldflags="$LDFLAGS"
cclib=''
ccdef=''
mlflags="$OCAMLFLAGS"
mloptflags="$OCAMLOPTFLAGS"
mlinc="$OCAMLINC"
objsuffix="o"
ocamlfind="auto"

# sanitize
LC_ALL=C
export LC_ALL
unset IFS


# help
help()
{
    cat <<EOF
usage: configure [options]

where options include:
  -installdir dir      installation directory
  -ocamllibdir dir     ocaml library directory
  -gmp                 use GMP library (default if found)
  -mpir                use MPIR library instead of GMP
  -perf                enable performance statistics
  -prefixnonocaml      add for non ocaml tool, e.g. -prefixnonocaml x86_64-w64-mingw32-

Environment variables that affect configuration:
  CFLAGS               extra flags to pass to the C compiler
  CPPFLAGS             extra includes, e.g. -I/path/to/gmp/include
  LDFLAGS              extra link flags, e.g. -L/path/to/gmp/lib
  OCAMLFLAGS           extra flags to pass to the ocamlc Caml compiler
  OCAMLOPTFLAGS        extra flags to pass to the ocamlopt Caml compiler
  OCAMLINC             extra includes to pass to the Caml compilers
EOF
    exit
}

# parse arguments
while : ; do
    case "$1" in
        "") 
            break;;
        -installdir|--installdir)
            installdir="$2"
            shift;;
        -ocamllibdir|--ocamllibdir)
            ocamllibdir="$2"
            shift;;
        -no-ocamlfind|--no-ocamlfind)
            ocamlfind="no"
            shift;;
        -help|--help)
            help;;
        -gmp|--gmp)
            gmp='gmp';;
        -mpir|--mpir)
            gmp='mpir';;
        -perf|--perf)
            perf='yes';;
        -prefixnonocaml|--prefixnonocaml)
            prefixnonocaml="$2"
            shift;;
        *)
            echo "unknown option $1, try -help"
            exit 2;;
    esac
    shift
done

if test "$perf" = "yes"; then ccdef="-DZ_PERF_COUNTER $ccdef"; fi

echo_n()
{
    echo "$1" | tr -d '\012'
}

# checking binaries in $PATH

searchbin()
{
    if test "x$1" = "x"; then return 0; fi
    echo_n "binary $1: "
    case "$1" in
      /*|./*|../*)
        if test -f "$1" && test -x "$1"
        then echo "found"; return 1
        else echo "not found"; return 0
        fi;;
    esac
    IFS=':'
    for i in $PATH
    do
        if test -z "$i"; then i='.'; fi
        if test -f $i/$1 && test -x $i/$1; then echo "found in $i"; unset IFS; return 1; fi
    done
    echo "not found"
    unset IFS
    return 0
}

searchbinreq()
{
    searchbin $1
    if test $? -eq 0; then echo "required program $1 not found"; exit 2; fi
}


# checking includes and libraries

checkinc()
{
    echo_n "include $1: "
    rm -f tmp.c tmp.o
    echo "#include <$1>" > tmp.c
    echo "int main() { return 1; }" >> tmp.c
    r=1
    $CC $ccopt $ccinc -c tmp.c -o tmp.o >/dev/null 2>/dev/null || r=0
    if test ! -f tmp.o; then r=0; fi
    rm -f tmp.c tmp.o
    if test $r -eq 0; then echo "not found"; else echo "found"; fi
    return $r
}

checklib()
{
    echo_n "library $1: "
    rm -f tmp.c tmp.out
    echo "int main() { return 1; }" > tmp.c
    r=1
    $CC $ccopt $ldflags $cclib tmp.c -l$1 -o tmp.out >/dev/null 2>/dev/null || r=0
    if test ! -x tmp.out; then r=0; fi
    rm -f tmp.c tmp.o tmp.out
    if test $r -eq 0; then echo "not found"; else echo "found"; fi
    return $r
}

checkcc()
{
    echo_n "checking compilation with $cc $ccopt: "
    rm -f tmp.c tmp.out
    echo "int main() { return 1; }" >> tmp.c
    r=1
    $CC $ccopt tmp.c -o tmp.out >/dev/null 2>/dev/null || r=0
    if test ! -x tmp.out; then r=0; fi
    rm -f tmp.c tmp.o tmp.out
    if test $r -eq 0; then echo "not working"; else echo "working"; fi
    return $r
}

checkcmxalib()
{
    echo_n "library $1: "
    $ocamlopt $mloptflags $1 -o tmp.out >/dev/null 2>/dev/null || r=0
    if test ! -x tmp.out; then r=0; fi
    rm -f tmp.out
    if test $r -eq 0; then echo "not found"; else echo "found"; fi
    return $r    
}


# check required programs

searchbinreq $ocaml
searchbinreq $ocamlc
searchbinreq $ocamldep
searchbinreq $ocamlmklib
if searchbin $ocamldoc; then
  ocamldoc=''
fi

if test -n "$CC"; then
  searchbinreq "$CC"
  ccopt="$CFLAGS"
else
  ccopt="-O3 -Wall -Wextra $CFLAGS"
fi

# optional native-code generation

hasocamlopt='no'

searchbin $ocamlopt
if test $? -eq 1; then hasocamlopt='yes'; fi


# check C compiler

checkcc
if test $? -eq 0; then
    # try again with (almost) no options
    ccopt='-O'
    checkcc
    if test $? -eq 0; then echo "cannot compile and link program"; exit 2; fi
fi


# directories

if test "$ocamllibdir" = "auto"
then ocamllibdir=`ocamlc -where | sed 's/\r$//'`
fi

if test ! -f "$ocamllibdir/caml/mlvalues.h"
then echo "cannot find OCaml libraries in $ocamllibdir"; exit 2; fi
ccinc="-I$ocamllibdir $ccinc"
checkinc "caml/mlvalues.h"
if test $? -eq 0; then echo "cannot include caml/mlvalues.h"; exit 2; fi


# optional dynamic linking

hasdynlink='no'

if test $hasocamlopt = yes
then
    checkcmxalib dynlink.cmxa
    if test $? -eq 1; then hasdynlink='yes'; fi
fi


# installation method

searchbin ocamlfind
if test $? -eq 1 && test $ocamlfind != "no"; then 
    instmeth='findlib'
    if test "$installdir" = "auto"
    then installdir=`ocamlfind printconf destdir`; fi
else
    searchbin install
    if test $? -eq 1; then instmeth='install'
    else echo "no installation method found"; exit 2; fi
    if test "$installdir" = "auto"; then installdir="$ocamllibdir"; fi
fi


# detect OCaml's word-size

echo "print_int (Sys.word_size);;" > tmp.ml
wordsize=`ocaml tmp.ml`
echo "OCaml's word size is $wordsize"
rm -f tmp.ml


# check GMP, MPIR

if test "$gmp" = 'gmp' || test "$gmp" = 'auto'; then
    if pkg-config gmp 2>/dev/null; then
        echo 'package gmp: found'
        gmp='OK'
        cclib="$cclib $(pkg-config --libs gmp)"
        ccinc="$ccinc $(pkg-config --cflags gmp)"
        ccdef="-DHAS_GMP $ccdef"
    else
        checkinc gmp.h
        if test $? -eq 1; then
            checklib gmp
            if test $? -eq 1; then 
                gmp='OK'
                cclib="$cclib -lgmp"
                ccdef="-DHAS_GMP $ccdef"
            fi
        fi
    fi
fi
if test "$gmp" = 'mpir' || test "$gmp" = 'auto'; then
    checkinc mpir.h
    if test $? -eq 1; then
        checklib mpir
        if test $? -eq 1; then 
            gmp='OK'
            cclib="$cclib -lmpir"
            ccdef="-DHAS_MPIR $ccdef"
        fi
    fi
fi
if test "$gmp" != 'OK'; then echo "cannot find GMP nor MPIR"; exit 2; fi


# OCaml version

ocamlver=`ocamlc -version`

# OCaml version 4.04 or later is required

case "$ocamlver" in
    [123].* | 4.0[0123].*)
        echo "OCaml version $ocamlver is no longer supported."
        echo "OCaml version 4.04.0 or later is required."
        exit 2
        ;;
esac

# -bin-annot available since 4.00.0
echo "OCaml supports -bin-annot to produce documentation"
hasbinannot='yes'

# Changes to C API (the custom_operation struct) since 4.08.0
case "$ocamlver" in
    [123].* | 4.0[01234567].* )
        echo "Using OCaml legacy C API custom operations"
        ccdef="-DZ_OCAML_LEGACY_CUSTOM_OPERATIONS $ccdef"
    ;;
    *)
    ;;
esac

# dump Makefile

cat > Makefile <<EOF
# generated by ./configure

OCAMLC=$ocamlc
OCAMLOPT=$ocamlopt
OCAMLDEP=$ocamldep
OCAMLMKLIB=$ocamlmklib
OCAMLDOC=$ocamldoc
OCAMLFLAGS=$mlflags
OCAMLOPTFLAGS=$mloptflags
OCAMLINC=$mlinc
CFLAGS=$ccinc $ccdef $ccopt
LIBS=$cclib
LDFLAGS=$ldflags
INSTALLDIR=$installdir
INSTALL=install
OCAMLFIND=ocamlfind
INSTMETH=$instmeth
OBJSUFFIX=$objsuffix
HASOCAMLOPT=$hasocamlopt
HASDYNLINK=$hasdynlink
HASBINANNOT=$hasbinannot

include project.mak
EOF


# dump summary

cat <<EOF

detected configuration:

  native-code:          $hasocamlopt
  dynamic linking:      $hasdynlink
  defines:              $ccdef
  includes:             $ccinc
  libraries:            $cclib
  linker options:       $ldflags
  C options:            $ccopt
  installation path:    $installdir
  installation method   $instmeth

configuration successful!
now type "make" to build
then type "make install" or "sudo make install" to install
EOF