#!/bin/bash
# 
# Common functions to copy binaries and their dependancies.
#
############################################################
#
# Usage: get_dynamic_dependencies [-l <searchdir>] <binary_list>
# 	  * the list must be seperated by spaces
#	  * the search for lib needed by a binary can be done locally,
#	    using the -l <searchdir> option
#
# Ouput: 
#	 Will simply echo list of required libraries

# List of libraries to exclude from
BLACKLIST="ld-linux linux-gate linux-vdso libc.so"
LOCALSEARCH=0
LOCALSEARCHDIR=""

CURRENT_BLACKLIST=$(echo ${BLACKLIST} | sed 's/ /\\|/g')

get_dynamic_dependencies() {
	
	if [ "x$1" == "x-l" ]; then
		LOCALSEARCH=1
		shift
		[ ! -d $1 ] && perror "Directory given does not exist, exiting."
		LOCALSEARCHDIR=$1
		shift
	fi	

	while [ $# != 0 ]; do
		local BINARY=$1
		shift

		local LDD_OUT="ldd_output"
		if ldd $BINARY > $LDD_OUT; then
			# Case 1: dynamic
			for LIB in $(cat $LDD_OUT | grep -v "${CURRENT_BLACKLIST}" | awk '{print $1 $2 $3}'); do
				# split the entry into an array, ex:
				# libm.so.6 => /lib/libm.so.6 would be split into:
				# liblink[0]   liblink[1]
				local liblink=(${LIB//=>/ })
				lib_search
			done
		else
			# Case 2: not a dynamic
			pdebug "\t\t\t(Not a dynamic.)"
			rm -f $LDD_OUT
			continue
		fi	
		rm -f $LDD_OUT
	done

}

lib_search(){

	# if activated, start by searching the lib locally
	if [ "x$LOCALSEARCH" == "x1" ]; then
		cd $LOCALSEARCHDIR
        	local LOCAL_MATCHES=$(find . -name "${liblink[0]}") # | awk -F '.' '{print $1}')".so\*)
		cd - &>/dev/null
	        if [ "x${LOCAL_MATCHES}" != "x" ]; then
        		for llib in ${LOCAL_MATCHES}; do
				get_link_chain "${LOCALSEARCHDIR}"/"${llib}" "${LOCALSEARCHDIR}"
				get_dynamic_dependencies -l "${LOCALSEARCHDIR}" "${llib}"
				CURRENT_BLACKLIST+="\|${liblink[0]}"
	                done
			# found the libs, we are done
			return
	        fi
		# mark local search as done
	fi

	# search the lib on the system since it was not found earlier
	if [ ! -z ${liblink[1]} ] && [ "x${liblink[1]}" != "xnot" ]; then
		# get chain of symlink for that lib
                get_link_chain ${liblink[1]}
		CURRENT_BLACKLIST+="\|${liblink[1]}"
        else
                pwarning "\t\tLib '${liblink[0]}' from required dir '$ENTRY' neither found in build directory nor on this system."
                pwarning "\t\tIf this lib is not supplied by another module, this module will probably fail in your final system"
        fi
}
############################################################
#
# Usage: get_link_chain <link> [prefix] 
#
#	<link> must be in absolute form-
#	[prefix] is the prefix to strip from the ouput.
#
# Output:
#	 Lists the symlink chain until a hardlink is found.
get_link_chain() {

	# sanity checks
	if [[ "$1" == /* ]]; then
		[ -e $1 ] || perror "get_link_chain: no such file: $1"
	else
		perror "get_link_chain() requires absolute paths, given: $1"
	fi
	if [ $# == 2 ] ; then
		[ ! -d $2 ] && perror "get_link_chain: $2 is not a directory."
		# got a prefix
		local PREFIX=$(readlink -f $2)
	else
		# mark prefix as not set
		local PREFIX="notset"
	fi

	# canonalize
	local LINK=$(canonicalize $1)

	local CHAIN="$LINK"

	# write the first link in the chain
	if [ "x$PREFIX" != "x" -a "x$PREFIX" != "xnotset" ]; then
		if [ "x${LINK#$PREFIX}" == "x${LINK}" ]; then
			# prefix was not in the link
			echo "$LINK"
		else
			# prefix was in the link
			echo ./"${LINK#$PREFIX}"
		fi 
	else
		# no prefix, copy like it is
		echo "$LINK"
	fi

	# now we check for symlinks
	local TRY=0
	while [ -L $LINK ] && [ $TRY -lt 10 ]; do
		let TRY=TRY+1

		# save the directory prefix
		CURRENTDIR=$(dirname ${LINK})
		# first follow the link
		LINK=$(readlink $LINK)
		CHAIN+=" -> $LINK"
		# $LINK can be absolute or relative, check cases
		[[ "$LINK" == /* ]] || LINK=$(canonicalize "$CURRENTDIR"/"${LINK}")
		# write the first link in the chain
	        if [ "x$PREFIX" != "x" -a "x$PREFIX" != "xnotset" ]; then
	                if [ "x${LINK#$PREFIX}" == "x${LINK}" ]; then
        	        	# prefix was not in the link
                	        echo "$LINK"
	                else
        	                # prefix was in the link
                	        echo ./"${LINK#$PREFIX}"
	                fi
        	else
                	# no prefix, copy like it is
	                echo "$LINK"
        	fi
	done
	pdebug "\t\t$CHAIN"
}

# Function to get libc and ld-linux
list_basic_libs() {
        for i in $(ldd ${SHELL})
        do
                [ $(echo $i | grep '^/' | grep -c ld) -eq 1 -o  $(echo $i | grep '^/' | grep -c libc.so) -eq 1 ] && get_link_chain $i
        done
}