cd src/

# Use newer version of config.guess and config.sub (see Trac #19724)
cp "$SAGE_ROOT"/config/config.* .

###############################################################################
# Set up environment variables, depending on SAGE_* settings:
# Note that GMP-ECM is written in C (and assembler) - no C++ sources.
###############################################################################

# We eventually use / add these settings (or parts of them) to "our" CFLAGS,
# e.g. "-march=..." or "-mcpu=..." and "-mtune=..." to let gcc generate better,
# processor-specific code, since ECM doesn't use them if we set our own:
# (But currently MPIR doesn't provide optimized settings either if we pass
# non-empty CFLAGS; of course the user could set such manually though.)
gmp_cc_pat='/^[ 	]*#[ 	]*define[ 	]\{1,\}__GMP_CC[ 	]\{1,\}/s/.*"\([^"]*\)"/\1/p'
gmp_cflags_pat='/^[ 	]*#[ 	]*define[ 	]\{1,\}__GMP_CFLAGS[ 	]\{1,\}/s/.*"\([^"]*\)"/\1/p'
gmp_header_file="$SAGE_LOCAL"/include/gmp.h

gmp_cc=`sed -n -e "$gmp_cc_pat" "$gmp_header_file"`
gmp_cflags=`sed -n -e "$gmp_cflags_pat" "$gmp_header_file"`
# At least /some/ newer versions of MPIR define __GMP_CC and __GMP_CFLAGS
# (also in gmp.h! -- how compatible is that?) to (literally) __MPIR_CC and
# __MPIR_CFLAGS, respectively, i.e., to preprocessor variables, so we might
# have to get the real strings from their definitions:
# (Since we currently only match string literals above, both variables would
# be empty in that case, and not contain the names of preprocessor variables.
# We could change the patterns to actually match any definition / "value".)
case "$gmp_cc" in __MPIR_CC|"")
    gmp_cc=`sed -n -e "${gmp_cc_pat/GMP/MPIR}" "$gmp_header_file"`
esac
case "$gmp_cflags" in __MPIR_CFLAGS|"")
    gmp_cflags=`sed -n -e "${gmp_cflags_pat/GMP/MPIR}" "$gmp_header_file"`
esac

# Extract GMP's/MPIR's settings of CC and CFLAGS from a system-wide installation
# (if present); these are only printed, for informational purposes.
system_gmp_h=""
for incdir in /usr/include /usr/local/include; do
    if [ -f $incdir/gmp.h ]; then
        system_gmp_h=$incdir/gmp.h
    fi
done
if [ -n "$system_gmp_h" ]; then
    system_gmp_cc=`sed -n -e "$gmp_cc_pat" $system_gmp_h`
    system_gmp_cflags=`sed -n -e "$gmp_cflags_pat" $system_gmp_h`
    case "$system_gmp_cc" in __MPIR_CC|"")
        system_gmp_cc=`sed -n -e "${gmp_cc_pat/GMP/MPIR}" $system_gmp_h`
    esac
    case "$system_gmp_cflags" in __MPIR_CFLAGS|"")
        system_gmp_cflags=`sed -n -e "${gmp_cflags_pat/GMP/MPIR}" $system_gmp_h`
    esac
fi


# libtool should add the proper flags, but doesn't use "-fPIC"
# for the *static* library (which the Sage library links to unless
# we also build the shared one). The following only handles the
# most common cases, not all variations with '=yes' or '=no' etc.:
if ! (echo $ECM_CONFIGURE | egrep -- "--enable-shared|--with-pic" >/dev/null) ||
     (echo $ECM_CONFIGURE | egrep -- "--disable-shared" >/dev/null);
then
    echo "Adding '-fPIC' to CFLAGS since we don't (also) build a shared library."
    CFLAGS="$CFLAGS -fPIC" # alternatively add '--with-pic' to 'configure' options
else
    # PIC usually slows down the execution, so don't use it for the *static*
    # library (unless '--with-pic' was given). libtool does the right thing
    # for the shared one we also build, which then will be used by Sage.
    echo "Not adding '-fPIC' since we also build a shared library Sage will link"
    echo "to, or '--with-pic' was given in ECM_CONFIGURE."
fi

if [ "$UNAME" == "CYGWIN" ]; then
    # Force shared library build only on Cygwin; it will not build otherwise
    ECM_CONFIGURE="$ECM_CONFIGURE --enable-shared --disable-static"
fi


if [ "$SAGE_DEBUG" = yes ]; then
    # Add debug symbols and disable optimization:
    echo >&2 "Warning: Setting SAGE_DEBUG=yes completely disables optimization."
    CFLAGS="-g -O0 $CFLAGS"
    echo "You may in addition (or instead) pass '--enable-assert' and/or"
    echo "'--enable-memory-debug' to GMP-ECM's 'configure' by setting (and"
    echo "of course exporting) ECM_CONFIGURE accordingly."
else
    # Enable optimization, may be overridden by user settings:
    case "`uname -srm | tr ' ' '-'`" in
        Darwin-9*-[Pp]ower*)
            # Don't add debug symbols because configure otherwise
            # fails due to a bus error in Apple's 'ld' when trying
            # to determine if global symbols are prefixed with an
            # underscore (cf. http://trac.sagemath.org/sage_trac/ticket/5847#comment:35 ff.):
            echo >&2 "Warning: Disabling debug symbols on MacOS X 10.5" \
                "PowerPC because of a linker (?) bug."
            echo >&2 "See http://trac.sagemath.org/sage_trac/ticket/5847#comment:35" \
                "ff. for details."
            echo >&2
            CFLAGS="-O3 $CFLAGS"
            ;;
        *)
            CFLAGS="-g -O3 $CFLAGS"
    esac
fi


if [ "$SAGE_FAT_BINARY" = yes ]; then
    # XXX Disable SSE2 on x86? (by passing '--enable-sse2=no' to 'configure')
    # XXX Disable asm-redc? Or pass some "generic" '--host=...' to 'configure'?
    echo >&2 "Warning: SAGE_FAT_BINARY is currently not really supported by this package."
    echo >&2 "         Add e.g. '--disable-asm-redc' and/or '--enable-sse2=no'"
    echo >&2 "         to ECM_CONFIGURE if you run into problems."
else
    # Tune the code generation to the machine we build on:
    cpu_params=""; other_gmp_cflags=""

    # Some gcc 4.0.x versions don't support '-march=native', and it's currently
    # not supported on all platforms supported by Sage:
    if touch foo.c && $CC -march=native -c foo.c &>/dev/null; then
        # The compiler supports '-march=native', but the assembler might not
        # support (some of) the instructions emitted with this (e.g. the
        # Apple assembler doesn't know AVX yet).
        cat >foo.c <<EOF
                double d;
                unsigned long fancy_insns() { return (unsigned long) d; }
                int main () { return 0; }
EOF
        if $CC -march=native -o foo foo.c &>/dev/null && ./foo >/dev/null; then
            cpu_params="-march=native"
        else
            echo >&2 "Warning: Your assembler apparently doesn't understand the instructions"
            echo >&2 "         your compiler ($CC) generates with '-march=native'."
            echo >&2 "         You might also try to compile GMP-ECM with (e.g.)"
            echo >&2 "             CFLAGS=\"-march=native -mno-avx\""
            echo >&2 "         to disable specific instruction set extension (in this case, AVX)."
        fi
    fi
    if [ -z "$cpu_params" ]; then
        # 'native' not supported, see if GMP / MPIR provides us some CPU type:
        for opt in $gmp_cflags; do
            case $opt in
                -march=*|-mcpu=*|-mtune=*|-mpower*|-mno-power*)
                    echo "Found CPU parameter in gmp.h: $opt"
                    cpu_params="$cpu_params $opt"
                    ;;
                 # perhaps add other options, too (e.g. for different compilers)
                 *) other_gmp_cflags="$other_gmp_cflags $opt"
            esac
        done
    fi
    rm -f foo.* foo
    # Only add them if CFLAGS do not already contain similar:
    if [ -n "$cpu_params" ] &&
        ! (echo "$CFLAGS" | egrep -- '-march=|-mcpu=|-mtune=|-mpower|-mno-power' >/dev/null);
    then
        echo "Using additional host-specific CFLAGS: $cpu_params"
        CFLAGS="$cpu_params $CFLAGS"
    fi
    if [ -n "$other_gmp_cflags" ]; then
        echo "Not using other CFLAGS provided by gmp.h: $other_gmp_cflags"
    fi
fi


echo
echo "Settings from SAGE_LOCAL/include/gmp.h:"
echo "  CC=$gmp_cc"
echo "  CFLAGS=$gmp_cflags"
if [ -n "$system_gmp_h" ]; then
    echo "Settings found in $system_gmp_h (currently not used):"
    echo "  CC=$system_gmp_cc"
    echo "  CFLAGS=$system_gmp_cflags"
fi

echo "Finally using:"
echo "  CC=$CC"
echo "  CFLAGS=$CFLAGS"
echo "  CPP=$CPP"
echo "  CPPFLAGS=$CPPFLAGS"
test -n "$CCAS" && echo "  CCAS=$CCAS"
test -n "$CCASFLAGS" && echo "  CCASFLAGS=$CCASFLAGS"
echo "  LDFLAGS=$LDFLAGS"
test -n "$LIBS" && echo "  LIBS=$LIBS"
echo "  ABI=$ABI"
echo "  M4=$M4"
echo "(These settings may still get overridden by 'configure' or Makefiles.)"

export CFLAGS # Not exported by 'sage-env'.  LDFLAGS are exported above if
              # necessary.  We currently don't set (or modify) any other
              # environment variables, so don't have to export them here.


###############################################################################
# Now configure ECM:
# (Note: Building (also) a *shared* library is disabled by default.
#        Add "--enable-shared" below if you want it, though one can
#        now pass extra 'configure' options through ECM_CONFIGURE.)
#        If you do so, i.e. add '--enable-shared' by default, also
#        adapt the logic regarding '-fPIC' above.
###############################################################################

echo
if [ -z "$ECM_CONFIGURE" ]; then
    echo "Now configuring GMP-ECM with the following options:"
else
    echo "Now configuring GMP-ECM with additional options as specified by" \
        "ECM_CONFIGURE:"
    echo "  $ECM_CONFIGURE"
    echo "Finally configuring GMP-ECM with the following options:"
fi
echo "  --prefix=\"$SAGE_LOCAL\""
echo "  --libdir=\"$SAGE_LOCAL/lib\""
echo "  --with-gmp=\"$SAGE_LOCAL\""
for opt in $ECM_CONFIGURE; do
    echo "  $opt"
done
if [ -z "$ECM_CONFIGURE" ]; then
    echo "You can set ECM_CONFIGURE to pass additional parameters,"
    echo "e.g. \"--enable-shared\" to also build a *shared* library,"
    echo "or \"--disable-sse2\" if you encounter problems on a Pentium III system."
fi
echo

sdh_configure --with-gmp="$SAGE_LOCAL" $ECM_CONFIGURE

###############################################################################
# Now build ECM:
###############################################################################

sdh_make

###############################################################################
# Remove old executable/header/libraries/manpage:
###############################################################################

echo
echo "Build succeeded.  Now removing old binary, header file, manual page and libraries..."
rm -f "$SAGE_LOCAL"/bin/ecm
rm -f "$SAGE_LOCAL"/lib/libecm.*
rm -f "$SAGE_LOCAL"/include/ecm.h
rm -f "$SAGE_LOCAL"/share/man/man1/ecm.1

###############################################################################
# Now install ECM:
###############################################################################

sdh_make_install
