#!/bin/sh

#
#  My mini-configure, used only for:
#
#	(1)  Setting compiler tool names
#	(2)  Determining assembly-level munging of C symbols
#	(3)  Setting defines for the makefiles in a simple manner
#
#  Tried to be somewhat compatible with the autoconf configure.
#    I hope this doesn't confuse people.
#
#  In a subsequent release, I'll probably integrate these tests into
#    autoconf and just use that.
#

#
# Starting definitions for variables
target=
silent=no
tool_vars="CC LD OBJCOPY"
tool_names="gcc ld objcopy"
tool_targeted="yes yes yes"
link_addrs="8000 2000 7C00"
path_parts=`echo ${PATH} | sed -e s/:/\ /g`

#
#  This part is very much taken from autoconf-2.10
#
#     Checking for options
#

ac_prev=
for ac_option
do

  # If the previous option needs an argument, assign it.
  if test -n "$ac_prev"; then
    eval "$ac_prev=\$ac_option"
    ac_prev=
    continue
  fi

  case "$ac_option" in
  -*=*) ac_optarg=`echo "$ac_option" | sed 's/[-_a-zA-Z0-9]*=//'` ;;
  *) ac_optarg= ;;
  esac

  # Accept the important Cygnus configure options, so we can diagnose typos.

  case "$ac_option" in

  -help | --help | --hel | --he)
    cat << EOF
Usage: configure [options] [target]
General Options:
  --help                  print this message
  --quiet, --silent       do not print \`checking...' messages
  --version               print the fact that this isn't autoconf ;-)
Target Options:
  --host=TARGET           synonym for \`--target'
  --target=TARGET         use \`TARGET' as a prefix to all of the tool names
EOF
    exit 0 ;;

  -q | -quiet | --quiet | --quie | --qui | --qu | --q \
  | -silent | --silent | --silen | --sile | --sil)
    silent=yes ;;

  -host | --host | --hos | --ho | --h \
  | -target | --target | --targe | --targ | --tar | --ta | --t)
    ac_prev=target ;;
  -host=* | --host=* | --hos=* | --ho=* | --h=* \
  | -target=* | --target=* | --targe=* | --targ=* | --tar=* | --ta=* | --t=*)
    target="$ac_optarg" ;;

  -version | --version | --versio | --versi | --vers)
    echo "mini-configure written by Erich Boleyn with parts from autoconf-2.10"
    exit 0 ;;

  -*)
    echo "Warning: unrecognized configure option: \"$ac_option\"" ;;

  *)
    target="$ac_option"
    ;;
  esac
done

#
#  Utility functions
#

get_substr()
{
	local get_local
	get_local=$(($2+2))
	eval $1=\$$get_local
}

count_substrs()
{
	local count_local
	eval $1=-1
	for count_local in $@ ; do
		eval $1=\$\(\(\$$1+1\)\)
	done
}

tool_failed()
{
	cat << EOF >> ../config.log

Tool \`$@' either failed tests or cannot be found.
EOF
	cat << EOF


FATAL ERROR in configuration !!

Tool \`$@' either failed tests or cannot be found.  Please make sure
that some standard local compiler, \`grep', \`sed', GNU \`gcc', and
the complete GNU binutils version 2.8.1 or beyond are installed.  The first
2 are used for automatic configuration, and the rest are required for
building GRUB.  The file \`config.log' contains the debugging output of
this run, and the subdirectory \`conftestdir' contains the files and
programs produced.
EOF
	exit 0
}

check_exit_status()
{
	exit_status=$?
	if [ $exit_status -ne 0 ]; then
		echo "Command failed with exit status $exit_status" >> ../config.log
		tool_failed $@
	fi
}

findtool()
{
	local tool pathstr fail
	echo -n "Looking for tool \`$1' ... " >> ../config.log
	tool=
	case "$1" in
	/*)
		if [ ! -e "$1" ]; then
			tool_failed $1
		fi
		tool=$1
		;;
	*)
		for pathstr in $path_parts ; do
			if [ -e "$pathstr/$1" ]; then
				tool="$pathstr/$1"
			fi
		done
		if [ "$tool" = "" ]; then
			tool_failed $1
		fi
		;;
	esac
	echo "found as \`$tool'" >> ../config.log
}

find_symbol_munge()
{
	local munge_local i tmpvar

	munge_local=`grep \.globl $2 | grep $1`
	count_substrs i $munge_local

	if [ $i -ne 2 ]; then
		tool_failed ${CC}
	fi

	munge_local=`echo $munge_local | sed -e s/\\.globl// | sed -e s/$1/\ x\ /`
	count_substrs i $munge_local

	get_substr tmpvar 1 $munge_local
	eval munge_$1=$tmpvar

	if [ $i -eq 2 ]; then
		get_substr tmpvar 2 $munge_local
		eval munge_$1="\"\$munge_$1 \\#\\# $tmpvar\""
	fi

	if [ $i -eq 3 ]; then
		get_substr tmpvar 3 $munge_local
		eval munge_$1="\"\$munge_$1 \\#\\# $tmpvar\""
	fi
}


# Cleanup from previous incomplete tests
if [ -d conftestdir ]; then
	rm -rf conftestdir
fi

# Clear configuration log
if [ -e config.log ]; then
	rm -rf config.log
fi

mkdir conftestdir
cd conftestdir

#
#  Find tools
#

if [ "$silent" != "yes" ]; then
	echo -n "checking for build tools... "
fi

# Initialize numbering
i=0

for tool_var in $tool_vars ; do
	i=$(($i+1))
	get_substr tool_name $i ${tool_names}
	eval tmpvar=\$\{$tool_var\}
	if [ "$tmpvar" = "" ]; then
		get_substr tmpvar $i ${tool_targeted}
		if [ "$target" != "" -a "$tmpvar" = "yes" ]; then
			tool_name=$target-$tool_name
		fi
		eval export $tool_var=$tool_name
	fi

	eval findtool \$\{$tool_var\}

	if [ "$silent" != "yes" ]; then
		echo -n "$tool_var "
	fi
done

if [ "$silent" != "yes" ]; then
	echo
fi

#
#  Create test C source file to determine how symbols are munged
#

if [ "$silent" != "yes" ]; then
	echo -n "checking C symbol munging in output of ${CC} ... "
fi

cat << EOF > test_sym.c

int
func1(int *list)
{
	list[1] = 0;

	return list[0];
}

double
func2(double a, int *list)
{
	list[0] = ((int) a) + list[1];

	return a;
}

EOF

echo "Compiling test_sym.c to assembly with ${CC}" >> ../config.log
${CC} -S test_sym.c >> ../config.log 2>&1
check_exit_status ${CC}

# Perform actual test(s) here

find_symbol_munge func1 test_sym.s
find_symbol_munge func2 test_sym.s

# if they are not equal, this simple compiling scheme will fail!

echo "C symbol amalgam macros (using \"x\" as base, and must match):" >> ../config.log
echo "        \"$munge_func1\" and \"$munge_func2\"" >> ../config.log

if [ "$munge_func1" != "$munge_func2" ]; then
	tool_failed ${CC}
	test $silent = yes || echo yes
else
	test $silent = yes || echo no
fi

#
#  Create test C source file to determine if our version of objcopy
#  is buggy
#

if [ "$silent" != "yes" ]; then
	echo -n "checking whether ${OBJCOPY} works... "
fi

cat << EOF > test_objcopy.c

void
blah(void)
{
	*((int *) 1000) = 2;
}

EOF

echo "Compiling test_objcopy.c with ${CC}" >> ../config.log
${CC} -nostdinc -c test_objcopy.c >> ../config.log 2>&1
check_exit_status ${CC}

# Perform actual test(s) here

for link_addr in $link_addrs ; do
	echo "Linking test_objcopy.o with ${LD} at $link_addr" >> ../config.log
	${LD} -N -Ttext $link_addr test_objcopy.o -o test_objcopy >> ../config.log 2>&1
	check_exit_status ${LD}
	${OBJCOPY} -O binary test_objcopy testout >> ../config.log 2>&1
	check_exit_status ${OBJCOPY}

	if [ -r testout.old ]; then
		cmp testout testout.old >> ../config.log 2>&1
		check_exit_status ${OBJCOPY}
	fi
	mv testout testout.old
done

if [ "$silent" != "yes" ]; then
	echo yes
fi

# Mass confusion!
# Older versions of GAS interpret `.code16' to mean ``generate 32-bit
# instructions, but implicitly insert addr32 and data32 bytes so
# that the code works in real mode''.
#
# Newer versions of GAS interpret `.code16' to mean ``generate 16-bit
# instructions,'' which seems right.  This requires the programmer
# to explicitly insert addr32 and data32 instructions when they want
# them.
#
# We only support the newer versions, because the old versions cause
# major pain, by requiring manual assembly to get 16-bit instructions into
# stage1/stage1.S.
if [ "$silent" != "yes" ]; then
	echo -n "checking whether GAS understands addr32... "
fi

cat > test_addr32.S <<EOF
	.code16
l1:	addr32
	movb	%al, l1
EOF

echo "Compiling test_addr32.S with ${CC}" >> ../config.log
${CC} -nostdinc -c test_addr32.S >> ../config.log 2>&1
check_exit_status GAS

test $silent != yes && echo yes

#
#  Write out results
#

cd ..

if [ ! -d bin ]; then
	mkdir bin
fi

#
#  Write config file
#

if [ "$silent" != "yes" ]; then
	echo -n "creating \`Makefile'... "
fi

cat << EOF > Makefile
#
#  This stub \`Makefile' was created automatically by configure.
#  (BEGINNING OF AUTOMATICALLY GENERATED PORTION)

EOF

for tool_var in $tool_vars ; do
	eval echo \"export $tool_var = \$\{$tool_var\}\" >> Makefile
done

cat << EOF >> Makefile
export SHARED_FLAGS = -pipe -fno-builtin -nostdinc -O2 -DEXT_C\(x\)="$munge_func1"

#  (END OF AUTOMATICALLY GENERATED PORTION)
#

EOF

cat Makefile.end >> Makefile

if [ "$silent" != "yes" ]; then
	echo done
fi

#
#  Delete test directory
#

rm -rf conftestdir