tools/shld.sh: Add a basic RTLD

1 files changed, 39 insertions, 6 deletions

diff --git a/tools/shld.sh b/tools/shld.sh
index 41751d3..3117ccf 100755
--- a/tools/shld.sh
+++ b/tools/shld.sh
@@ -2,7 +2,7 @@
 #
 # Shell command language linker
 #
-# Copyright (C) 2015  Patrick "P. J." McDermott
+# Copyright (C) 2015, 2019  Patrick "P. J." McDermott
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -19,7 +19,7 @@
 
 set -u
 
-VERSION='0.2.0'
+VERSION='0.3.0'
 
 die()
 {
@@ -35,8 +35,9 @@ link()
 	local make_executable="${1}"
 	local interpreter="${2}"
 	local entry_point="${3}"
-	local output="${4}"
-	shift 4
+	local libs="${4}"
+	local output="${5}"
+	shift 5
 	local input=
 
 	# Open output file.
@@ -58,6 +59,33 @@ link()
 		}
 		EOF
 
+	# Write __DT_NEEDED list and basic RTLD.
+	printf "__DT_NEEDED='%s'\n" "${libs}" >&3
+	cat >&3 <<-'EOF'
+		: ${SHLD_LIBRARY_PATH:=${LIBDATADIR}}
+		for __lib in ${__DT_NEEDED}; do
+			__found=false
+			IFS=':'
+			for __el in ${SHLD_LIBRARY_PATH}; do
+				if __f="$(cat "${__el}/${__lib}" 2>/dev/null)"
+				then
+					eval "${__f}"
+					__found=true
+					break
+				fi
+			done
+			unset IFS
+			if ! ${__found}; then
+				printf "%s: error while loading shell $(: \
+					)shared libraries: %s: cannot open $(: \
+					)shell shared object file\n" \
+					"${0}" "${__lib}" >&2
+				exit 127
+			fi
+		done
+		unset __lib __el __found
+		EOF
+
 	# Read input files.
 	for input in "${@}"; do
 		if ! cat "${input}" >&3; then
@@ -101,6 +129,7 @@ help()
 Options:
   -h           Display this information
   -V           Display linker version information
+  -l <lib>     Add <lib> to the list of libraries to load at run time
   -I <interp>  Make an executable and use <interp> as the interpreter for your
                program, instead of the default of "/bin/sh"
   -e <entry>   Make an executable and use <entry> as the function for beginning
@@ -124,12 +153,13 @@ EOF
 main()
 {
 	local opt=
+	local libs=''
 	local make_executable=false
 	local interpreter='/bin/sh'
 	local entry_point='main'
 	local output='out.sh'
 
-	while getopts 'hVI:e:o:' opt; do
+	while getopts 'hVl:I:e:o:' opt; do
 		case "${opt}" in
 			'h')
 				help
@@ -139,6 +169,9 @@ main()
 				version
 				exit
 				;;
+			'l')
+				libs="${libs}${OPTARG} "
+				;;
 			'I')
 				interpreter="${OPTARG}"
 				make_executable=true
@@ -159,7 +192,7 @@ main()
 		exit 1
 	fi
 
-	link "${make_executable}" "${interpreter}" "${entry_point}" \
+	link "${make_executable}" "${interpreter}" "${entry_point}" "${libs}" \
 		"${output}" "${@}"
 }