#!/bin/sh

#this script is brutal and verbose, has no tricks and is quite linear, then
#quite easy to deal with
#for the moment, it's hardcoded for a gcc toolchain... BAD! Since now
#gcc is a c++ piece of shit

# stolen from ffmpeg configure like a pig
set -e

# prevent locale nonsense from breaking basic text processing
LC_ALL=C
export LC_ALL

# libtool versioning?? Is age ok??
libkmod_api=2
libkmod_rev=3
libkmod_age=2
libkmod_so_version=${libkmod_api}.${libkmod_rev}.${libkmod_age}
fake_root=fake_root
#-------------------------------------------------------------------------------

# it's benign here, but keep in mind it does define the order of static linking
# which is important for proper symbol selection
libkmod_src_files='
src/libkmod.c
src/libkmod-list.c
src/libkmod-config.c
src/libkmod-index.c
src/libkmod-module.c
src/libkmod-file.c
src/libkmod-elf.c
src/libkmod-signature.c
src/shared/util.c
src/shared/strbuf.c
src/shared/hash.c
'

# it's benign here, but keep in mind it does define the order of static linking
# which is important for proper symbol selection
kmod_src_files='
src/tools/kmod.c
src/tools/lsmod.c
src/tools/rmmod.c
src/tools/insmod.c
src/tools/modinfo.c
src/tools/modprobe.c
src/tools/depmod.c
src/tools/static-nodes.c
src/tools/log.c
src/shared/util.c
src/shared/strbuf.c
src/shared/hash.c
src/shared/array.c
src/shared/scratchbuf.c
'
#-------------------------------------------------------------------------------

sep_start()
{
printf '###############################################################################\n'
}

sep_end()
{
printf '###############################################################################\n\n'
}

subsep_start()
{
printf '*******************************************************************************\n'
}

subsep_end()
{
printf '*******************************************************************************\n'
}

################################################################################

if test -f make; then
	src_path=.
else
	src_path=$(cd $(dirname "$0"); pwd)
	echo "$src_path" | grep -q '[[:blank:]]' &&
		die "out of tree builds are impossible with whitespace in source path."
fi

################################################################################

is_in()
{
value=$1
shift
for var in $*; do
	[ $var = $value ] && return 0
done
return 1
}

die_unknown()
{
echo "Unknown option \"$1\"."
echo "See $0 --help for available options."
exit 1
}

set_default()
{
for opt; do
    eval : \${$opt:=\$${opt}_default}
done
}

spaces_concat()
{
printf "$1" | tr -s '[:space:]' ' '
}

CMDLINE_SET='
bin_cc
bin_ccld
libkmod_cc
libkmod_ar
dbin_cc
dbin_ccld
slibkmod_cc
slibkmod_ccld
prefix
bindir
libdir
includedir
sysconfdir
version
'

################################################################################

#command line set defaults
#-------------------------------------------------------------------------------
bin_cc_default="gcc		-Wall -Wextra -Wno-unused-parameter		\
				-Wno-format-truncation				\
				-std=gnu99 -O2 -c"

bin_ccld_default="gcc		-static"

libkmod_cc_default="gcc		-Wall -Wextra -Wno-unused-parameter		\
				-std=gnu99 -O2 -fPIC -c"

libkmod_ar_default="ar 		rcs"

dbin_cc_default="gcc		-Wall -Wextra -Wno-unused-parameter		\
				-Wno-format-truncation				\
				-std=c99 -O2 -c"

dbin_ccld_default="gcc		-Wl,--as-needed"

slibkmod_cc_default="gcc	-Wall -Wextra -Wno-unused-parameter		\
				-std=c99 -O2 -fPIC -c"

slibkmod_ccld_default="gcc	-shared						\
				-Wl,--version-script=$src_path/libkmod.sym	\
				-Wl,-soname,libkmod.so.$libkmod_api		\
				-Wl,--as-needed"
#-------------------------------------------------------------------------------

prefix_default=/usr/local
bindir_default='$prefix/bin'
libdir_default='$prefix/lib'
includedir_default='$prefix/include'
sysconfdir_default='$prefix/etc'
version_default=24
set_default $CMDLINE_SET

libkmod_only=no
disable_static=no
disable_dynamic=no

################################################################################


################################################################################

show_help(){
    cat <<EOF
Usage: make [options]

default to build libkmod and kmod

Options: [defaults in brackets after descriptions]

Help options:
  --help               print this message

Standard options:
  --libkmod-only       build only libkmod
  --disable-static     disable the build of static lib and static binary
  --disable-dynamic    disable the build of shared lib and dynamic binary

  --prefix=PREFIX      architecture independent prefix [$prefix_default]
  --eprefix=EPREFIX    architecture dependent exec prefix [$eprefix_default]
  --libdir=DIR         object code libraries [$libdir_default]
  --includedir=DIR     C header files [$includedir_default]
  --sysconfdir=DIR     read-only single-machine data [$sysconfdir_default]

  --version=VERSION    override the version number [$version_default]

Advanced options:
  --bin-cc=CC          use C compiler command line CC for static target kmod [$(spaces_concat "$bin_cc_default")]
  --bin-ccld=CCLD      use linker command line CCLD for static target kmod [$(spaces_concat "$bin_ccld_default")]

  --dbin-cc=CC         use C compiler command line CC for dynamic target kmod [$(spaces_concat "$dbin_cc_default")]
  --dbin-ccld=CCLD     use linker command line CCLD for dynamic target kmod [$(spaces_concat "$dbin_ccld_default")]

  --libkmod-cc=CC      use C compiler command line CC for static target libkmod [$(spaces_concat "$libkmod_cc_default")]
  --libkmod-ar=AR      use archive command line AR for static target libkmod [$(spaces_concat "$libkmod_ar_default")]

  --slibkmod-cc=CC     use C compiler command line CC for shared target libkmod [$(spaces_concat "$slibkmod_cc_default")]
  --slibkmod-ccld=CCLD use linker command line CCLD for shared target libkmod [$(spaces_concat "$slibkmod_ccld_default")]
EOF
  exit 0
}

################################################################################

for opt do
	optval="${opt#*=}"
	case "$opt" in
		--help|-h) show_help
		;;
		--libkmod-only)
			libkmod_only=yes
		;;
		--disable-static)
			disable_static=yes
		;;
		--disable-dynamic)
			disable_dynamic=yes
		;;
		*)
			optname=${opt%%=*}
			optname=${optname#--}
			optname=$(echo "$optname" | sed 's/-/_/g')
			if is_in $optname $CMDLINE_SET; then
				eval $optname='$optval'
			else
				die_unknown $opt
			fi
		;;
	esac
done

################################################################################

sep_start;echo "source path is $src_path";sep_end

path_expand()
{
	e_v=$1
	#we set a maximum expansion depth of 3
	for d in 1 2 3
	do
	    e_v=$(eval echo "$e_v")
	done
	#get rid of ugly double // in path
	echo "$e_v" | sed -e 's%//%/%g'
}

sep_start;echo 'expanding final paths:'
e_prefix=$(path_expand "$prefix")
e_bindir=$(path_expand "$bindir")
e_libdir=$(path_expand "$libdir")
e_includedir=$(path_expand "$includedir")
e_sysconfdir=$(path_expand "$sysconfdir")
echo "prefix=$e_prefix"
echo "bin=$e_bindir"
echo "libdir=$e_libdir"
echo "includedir=$e_includedir"
echo "sysconfdir=$e_sysconfdir"
sep_end

################################################################################

mkdir -p -- ./src
printf "#ifndef LIBKMOD_PATHS_H\n#define LIBKMOD_PATHS_H\n#define SYSCONFDIR \"%b\"\n#endif" "$e_sysconfdir" >./src/libkmod-paths.h

################################################################################

. $src_path/make.libkmod.sh
if test x$libkmod_only != xyes; then
	. $src_path/make.kmod.sh
fi

################################################################################

sep_start;echo 'generating pkg-config file for libkmod'
mkdir -p -- $fake_root$e_libdir/pkgconfig
cp -f $src_path/libkmod.pc.in $fake_root$e_libdir/pkgconfig/libkmod.pc
sed -i "s%@VERSION@%$version%" $fake_root$e_libdir/pkgconfig/libkmod.pc
sed -i "s%@libdir@%$e_libdir%" $fake_root$e_libdir/pkgconfig/libkmod.pc
sed -i "s%@includedir@%$e_includedir%" $fake_root$e_libdir/pkgconfig/libkmod.pc
sep_end