dylink.sh

########################################################################
#                                                                      #
#              This file is part of the ksh 93u+m package              #
#          Copyright (c) 2021-2026 Contributors to ksh 93u+m           #
#                      and is licensed under the                       #
#                 Eclipse Public License, Version 2.0                  #
#                                                                      #
#                A copy of the License is available at                 #
#      https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html      #
#         (with md5 checksum 84283fa8859daf213bdda5a9f8d1be1d)         #
#                                                                      #
#                  Martijn Dekker <martijn@inlv.org>                   #
#            Johnothan King <johnothanking@protonmail.com>             #
#                                                                      #
########################################################################

# Dynamic library linking tool for ksh 93u+m and supporting libraries.
# Called from **/Mamfile.

case ${ZSH_VERSION+z} in
z)	emulate ksh ;;
*)	(command set -o posix) 2>/dev/null && set -o posix ;;
esac
set -o noglob	# avoid pathname expansion interfering with field splitting
CCn='
'  # newline

case $(getopts '[-][123:xyz]' opt --xyz 2>/dev/null; echo 0$opt) in
0123)	optstring=$'
[-?
@(#)$Id: dylink (ksh 93u+m) 2026-09-14 $
]
[-author?Martijn Dekker <martijn@inlv.org>]
[-copyright?(c) 2021-2026 Contributors to ksh 93u+m]
[-license?https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html]
[+NAME?dylink - dynamic library linking tool for ksh 93u+m and supporting libraries]
[+DESCRIPTION?The \bdylink\b command is called from \b**/Mamfile\b to build
    dynamically linked shared libraries and executables that use them. It
    detects whether dynamic libraries are supported on the current system,
    and if so, invokes the C compiler and linker to produce a dynamic
    library or link an executable against one. Each non-option argument is
    a *.o object file built by the compiler.]
[+?With \b-Q\b, \bdylink\b only queries whether dynamic libraries are
    supported on the current system; no other options or arguments may be
    given.]
[+?Without \b-Q\b, either \b-e\b or \b-m\b must be given (but not both) to
    specify what should be built.]
[Q?Query support for dynamic libraries on this system. Exits 0 if supported,
    1 if not. Must be used alone.]
[e]:[exec-file?Link \aexec-file\a as an executable against the dynamic
    libraries specified by \b-l\b.]
[m]:[module-name?Build a dynamic library named \amodule-name\a. Requires
    \b-v\b, \b-p\b, and \b-s\b.]
[l]:[libname?Link against \blib\b\alibname\a. To link against multiple
    libraries, specify this option multiple times.]
[v]:[version?The dynamic library version for the file name, e.g. \b6.0\b.
    Used with \b-m\b.]
[p]:[prefix?The operating system'\'$'s dynamic library file name prefix.
    Must be \blib\b or empty. Used with \b-m\b.]
[s]:[suffix?The dynamic library file name suffix, e.g. \b.so\b or
    \b.dylib\b. Used with \b-m\b.]

[ objectfile ... ]

[+SEE ALSO?\bmamake\b(1), \bmkdeps\b(1)]\n'
	;;
*)	optstring='Qe:m:l:v:p:s:';
	;;
esac

note()
{
	printf "${0##*/}: %s\\n" "$@" >&2
}

err_out()
{
	note "$@"
	exit 3
}

do_link()
{
	target=$dest_dir/$1
	shift
	test -e "$target" && rm -f "$target"
	(
		PS4="[dylink] $PS4"
		set -o xtrace
		# why pass CCFLAGS here? because it *might* have a flag like -m64 that the linker also needs
		${CC:-cc} $CCFLAGS $LDFLAGS -o "$target" "$@"
	) || exit
}

# Basic sanity check.
case ${HOSTTYPE:+H}${INSTALLROOT:+I} in
HI)	;;
*)	err_out "Required environment missing"
	;;
esac

# Parse options.
unset opt_query exec_file module_name l_flags version prefix suffix
deproot=$INSTALLROOT/lib/lib
while getopts "$optstring" opt
do	case $opt in
	Q)	opt_query=y         # query support for dynamic libraries on this system
		;;
	e)	exec_file=$OPTARG
		;;
	m)	test -n "${module_name+m}" && err_out "-m cannot be used more than once"
		test -n "${l_flags+l}" && err_out "-m cannot be used after -l"
		test -f "$OPTARG.req" || err_out "$OPTARG.req not found -- generate it with mkreq(1)"
		l_flags=$(sed 1d "$OPTARG.req") || exit
		module_name=$OPTARG
		;;
	l)	if	test -f "$OPTARG.req"
		then	l_flags=${l_flags:+$l_flags$CCn}$(cat "$OPTARG.req") || exit
		elif	test -f "$deproot/$OPTARG"
		then	l_flags=${l_flags:+$l_flags$CCn}$(cat "$deproot/$OPTARG") || exit
		else	l_flags=${l_flags:+$l_flags$CCn}\ -l$OPTARG
		fi
		;;
	v)	version=$OPTARG     # this should be like 6.0
		;;
	p)	prefix=$OPTARG      # this should be 'lib' or empty
		;;
	s)	suffix=$OPTARG      # this should be like .dylib or .so
		;;
	'?')	exit 2
		;;
	*)	err_out "Internal error (getopts)"
		;;
	esac
done
shift $((OPTIND - 1))

# Validate options.
case ${opt_query+Q}${exec_file:+e}${module_name:+m}${l_flags+l}${version+v}${prefix+p}${suffix+s} in
Q?*)	err_out "-Q cannot be used with other options" ;;
Q)	test "$#" -gt 0 && err_out "-Q cannot be used with arguments" ;;
e | e[!m]* | m*)
	;;
*)	err_out "Either -e or -m should be specified" ;;
esac
case ${module_name:+m}${prefix+p}${suffix+s}${version:+v} in
'' | mpsv )
	case $prefix in
	'' | lib)
		;;
	*)	err_out "the -p option value must be 'lib' or ''"
	;;
	esac
	;;
msv)	note "warning: -p not given; assuming -p lib for backward compat"
	prefix=lib
	;;
*)	err_out "-m requires -v/-p/-s and vice versa"
	;;
esac

# Check if building dynamic libraries was disabled.
case ${AST_NO_DYLIB+N}${opt_query+Q} in
NQ)	exit 1
	;;
N)	note "Building dynamic libraries was disabled; skipping"
	exit 0  # continue build
	;;
esac

# Check for supported system.
case $HOSTTYPE in
android.* | darwin.* | dragonflybsd.* | freebsd* | haiku.* | linux.* | netbsd.* | openbsd.* | qnx.* | sol??.* )
	# supported
	test -n "$opt_query" && exit 0
	;;
cygwin.*)
	test -n "$opt_query" && exit 1
	note "Dynamic libraries are not supported on Cygwin."
	exit 0  # continue build
	;;
*)	case ${AST_DYLIB_TEST:+y} in
	y)	test -n "$opt_query" && exit 0
		;;
	*)	test -n "$opt_query" && exit 1
		note "The system $HOSTTYPE is currently untested for dynamic libraries" \
			"so dynamic libraries are disabled by default. To test them," \
			"export AST_DYLIB_TEST to try to build a dynamically linked ksh."
		exit 0  # continue build
		;;
	esac
	;;
esac

# Set destination directory.
dest_dir=$INSTALLROOT/dyn
mkdir -p "$dest_dir/bin" "$dest_dir/lib" || err_out "could not mkdir"

# Deduplicate -l flags and convert them to static linkage where necessary.
# Keep the last-mentioned of each item that occurs multiple times (this is
# required for passing libraries to the linker in the correct order; that
# is, each dependency must come after all the libraries that depend on it).
dupes=$l_flags
l_flags=
while	test -n "$dupes"
do	# Grab first item from dupes
	item=${dupes%%"$CCn"*}
	# Remove that item from dupes
	dupes=${dupes#"$item"}
	dupes=${dupes#"$CCn"} # remove $CCn separately as last item won't end in it
	# Skip the item if another identical item is still in dupes
	case "$CCn$dupes$CCn" in
	*"$CCn$item$CCn"*)
		continue ;;
	esac
	# If item was locally compiled but only as a static library, convert it to static linkage (path to lib${name}.a)
	name=${item# -l}
	case $(set +o noglob; set -- $dest_dir/lib/lib$name.* $dest_dir/lib/$name.*; printf '%s' "$#,$1,$2") in
	"2,$dest_dir/lib/lib$name.*,$dest_dir/lib/$name.*")
		# Unchanged glob patterns = the dynamic library does not exist in our local build tree.
		# If there is no local static library either, leave it alone; it's probably an OS library.
		if	test -f $INSTALLROOT/lib/lib${name}.a
		then	item=" $INSTALLROOT/lib/lib${name}.a"
		fi ;;
	esac
	# Add item to new space-separated l_flags
	l_flags="$l_flags$item"
done

# Do the dynamic linking.
case ${exec_file} in
'')	# ... figure out library file name(s) and internal name for linking purposes
	#     on macOS we have version before extension (libast.6.0.dylib), on other systems, after (libast.so.6.0)
	case $suffix in
	.dylib)	lib_file=$prefix$module_name.$version$suffix
		lib_linkname=$prefix$module_name.${version%%.*}$suffix
		;;
	*)	lib_file=$prefix$module_name$suffix.$version
		lib_linkname=$prefix$module_name$suffix.${version%%.*}
		;;
	esac
	sym_links="$lib_linkname $prefix$module_name$suffix"
	# ... remove possible old versions
	(set +o noglob; exec rm -f "$dest_dir/lib/$prefix$module_name".*)
	# ... execute linker command
	case $HOSTTYPE in
	darwin.*)
		do_link "lib/$lib_file" -dynamiclib \
			-Wl,-dylib_install_name -Wl,"@rpath/$lib_linkname" \
			"$@" -L"$dest_dir/lib" $l_flags
		;;
	*)	do_link "lib/$lib_file" -shared -Wl,-soname -Wl,"$lib_linkname" \
			"$@" -L"$dest_dir/lib" $l_flags
		;;
	esac
	for f in $sym_links
	do	ln -sf "$lib_file" "$dest_dir/lib/$f"
	done
	;;
*)	# Link an executable.
	case $HOSTTYPE in
	darwin.*)
		# since macOS SIP broke DYLD_LIBRARY_PATH, add a temporary @rpath
		do_link "bin/$exec_file" "$@" -headerpad_max_install_names -L"$dest_dir/lib" $l_flags
		install_name_tool -add_rpath "$dest_dir/lib" "$dest_dir/bin/$exec_file"
		;;
	*)
		do_link "bin/$exec_file" "$@" -L"$dest_dir/lib" $l_flags
		;;
	esac
	;;
esac