1 files changed, 20 insertions(+), 7 deletions(-)

M build_util.sh

@@ 24,12 24,6 @@ pecho()
 	printf '%s\n' "$*"
 }
 
-# Return the value of variable named $1
-value()
-{
-	eval pecho "\"\$$1\""
-}
-
 # Print all arguments to stderr and exits with status 1
 die()
 {


@@ 37,6 31,22 @@ die()
 	exit 1
 }
 
+# Check if the variable named $1 exists
+isset()
+{
+	eval "[ \"\${$1+x}\" ]"
+}
+
+# Return the value of variable named $1, fails if no such variable exists
+value()
+{
+	match "$1" '[0-9]+' &&
+		{ pecho "positional parameters can't be used with value()" >&2; return 1; }
+	isset "$1" ||
+		{ pecho "$var: variable not set" >&2; return 1; }
+	eval pecho "\"\$$1\""
+}
+
 # Append to variable $1, which need not exists
 append()
 {


@@ 68,7 78,7 @@ typecheck()
 	for var
 	do
 		match "$var" '[0-9]+' && die "positional parameters can't be used with typecheck"
-		val=$(value "$var")
+		val=$(value "$var") || exit 1
 		case "$type" in
 			bool)
 				[ "$val" != true ] && [ "$val" != false ] && {


@@ 94,6 104,9 @@ typecheck()
 					success=false
 				}
 				;;
+			*)
+				die "$type: unknown type"
+				;;
 		esac
 	done
 	$success