unified checks for variable initialisation

new function chkvars() does the job

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/git.sh

@@ -52,8 +52,7 @@ fetch_project_repo()
 	eval "$(setvars "" xtree tree_depend)"
 
 	scan_config "$project" "config/git"
-	[ -z "${loc+x}" ] && $err "fetch_project_repo $project: loc not set"
-	[ -z "${url+x}" ] && $err "fetch_project_repo $project: url not set"
+	chkvars loc url
 
 	[ -n "$xtree" ] && [ ! -d "src/coreboot/$xtree" ] && \
 		x_ ./update trees -f coreboot "$xtree"
@@ -87,7 +86,7 @@ git_prep()
 	_patchdir="$3" # $1 and $2 are gitrepo and gitrepo_backup
 	_loc="$4"
 
-	[ -z "${rev+x}" ] && $err "git_prep $_loc: rev not set"
+	chkvars rev
 
 	tmpclone "$1" "$2" "$tmpgit" "$rev" "$_patchdir"
 	if singletree "$project" || [ $# -gt 4 ]; then
@@ -130,9 +129,7 @@ fetch_submodule()
 
 	[ -z "$st" ] && return 0 # subrepo/subfile not defined
 
-	for mvar in "sub${st}" "sub${st}_bkup" "subhash"; do
-		eval "[ -n \"\$$mvar\" ] || $err \"$1, $mdir: $mvar unset\""
-	done
+	chkvars "sub${st}" "sub${st}_bkup" "subhash"
 
 	if [ "$st" = "repo" ]; then
 		rm -Rf "$tmpgit/$1" || $err "!rm '$mdir' '$1'"

include/lib.sh

@@ -41,6 +41,12 @@ setvars()
 	done
 	printf "%s\n" "${_setvars% }"
 }
+chkvars()
+{
+	for var in $@; do
+		eval "[ -n "\${$var+x}" ] || \$err \"$var unset\""
+	done
+}
 
 eval "$(setvars "" xbmk_release tmpdir _nogit version board boarddir relname \
     versiondate threads projectname projectsite aur_notice cfgsdir datadir)"
@@ -112,7 +118,7 @@ versiondate_="$versiondate"
 [ ! -e ".git" ] || versiondate="$(git show --no-patch --no-notes \
     --pretty='%ct' HEAD)" || versiondate="$versiondate_"
 for p in projectname version versiondate projectsite; do
-	eval "[ -n \"\$$p\" ] || $err \"$p unset\""
+	chkvars "$p"
 	eval "x_ printf \"%s\\n\" \"\$$p\" > $p"
 done
 relname="$projectname-$version"

include/mrc.sh

@@ -8,9 +8,7 @@ eval "$(setvars "" MRC_url MRC_url_bkup MRC_hash MRC_board SHELLBALL)"
 
 extract_mrc()
 {
-	[ -z "$MRC_board" ] && $err "extract_mrc $MRC_hash: MRC_board not set"
-	[ -z "$CONFIG_MRC_FILE" ] && $err "$MRC_hash: CONFIG_MRC_FILE unset"
-
+	chkvars "MRC_board" "CONFIG_MRC_FILE"
 	SHELLBALL="chromeos-firmwareupdate-$MRC_board"
 
 	(
@@ -49,7 +47,7 @@ extract_refcode()
 	# cbfstool changed the attributes scheme for stage files,
 	# incompatible with older versions before coreboot 4.14,
 	# so we need coreboot 4.13 cbfstool for certain refcode files
-	[ -n "$cbfstoolref" ] || $err "$board: MRC_refcode_cbtree not set"
+	chkvars cbfstoolref
 	mkdir -p "${_refdest%/*}" || $err "ref: !mkdir -p ${_refdest%/*}"
 
 	"$cbfstoolref" "$appdir/bios.bin" extract \