diff --git a/build/toolbase/label.go b/build/toolbase/label.go
new file mode 100644
index 0000000..b6e8fda
--- /dev/null
+++ b/build/toolbase/label.go
@@ -0,0 +1,87 @@
+package toolbase
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+// BazelLabel is a label, as defined by Bazel's documentation:
+//
+// https://docs.bazel.build/versions/main/skylark/lib/Label.html
+type BazelLabel struct {
+	WorkspaceName string
+	PackagePath   []string
+	Name          string
+}
+
+func (b BazelLabel) Package() string {
+	return strings.Join(b.PackagePath, "/")
+}
+
+func (b BazelLabel) String() string {
+	return fmt.Sprintf("@%s//%s:%s", b.WorkspaceName, b.Package(), b.Name)
+}
+
+var (
+	// reLabel splits a Bazel label into a workspace name (if set) and a
+	// workspace root relative package/name.
+	reLabel = regexp.MustCompile(`^(@[^:/]+)?//(.+)$`)
+	// rePathPart matches valid label path parts.
+	rePathPart = regexp.MustCompile(`^[^:/]+$`)
+)
+
+// ParseBazelLabel converts parses a string representation of a Bazel Label. If
+// the given representation is invalid or for some other reason unparseable,
+// nil is returned.
+func ParseBazelLabel(s string) *BazelLabel {
+	res := BazelLabel{
+		WorkspaceName: "dev_source_monogon",
+	}
+
+	// Split label into workspace name (if set) and a workspace root relative
+	// package/name.
+	m := reLabel.FindStringSubmatch(s)
+	if m == nil {
+		return nil
+	}
+	packageRel := m[2]
+	if m[1] != "" {
+		res.WorkspaceName = m[1][1:]
+	}
+
+	// Split path by ':', which is the target name delimiter. If it appears
+	// exactly once, interpret everything to its right as the target name.
+	targetSplit := strings.Split(packageRel, ":")
+	switch len(targetSplit) {
+	case 1:
+	case 2:
+		packageRel = targetSplit[0]
+		res.Name = targetSplit[1]
+		if !rePathPart.MatchString(res.Name) {
+			return nil
+		}
+	default:
+		return nil
+	}
+
+	// Split the package path by /, and if the name was not explicitly given,
+	// use the last element of the package path.
+	if packageRel == "" {
+		res.PackagePath = nil
+	} else {
+		res.PackagePath = strings.Split(packageRel, "/")
+	}
+	if res.Name == "" {
+		res.Name = res.PackagePath[len(res.PackagePath)-1]
+	}
+
+	// Ensure all parts of the package path are valid.
+	for _, p := range res.PackagePath {
+		if !rePathPart.MatchString(p) {
+			return nil
+		}
+	}
+
+	return &res
+}