diff --git a/cmd/tools/missdoc.v b/cmd/tools/missdoc.v
new file mode 100644
index 0000000000..20e34d4a6f
--- /dev/null
+++ b/cmd/tools/missdoc.v
@@ -0,0 +1,83 @@
+// Copyright (c) 2020 Lars Pontoppidan. All rights reserved.
+import os
+
+struct UndocumentedFN {
+	line      int
+	signature string
+}
+
+fn collect(path string, mut l []string, f fn (string, mut []string)) {
+	if !os.is_dir(path) {
+		return
+	}
+	mut files := os.ls(path) or { return }
+	for file in files {
+		p := path + os.path_separator + file
+		if os.is_dir(p) && !os.is_link(p) {
+			collect(p, mut l, f)
+		} else if os.exists(p) {
+			f(p, mut l)
+		}
+	}
+	return
+}
+
+fn report_undocumented_functions_in_path(path string) {
+	mut files := []string{}
+	collect_fn := fn (path string, mut l []string) {
+		if os.file_ext(path) == '.v' {
+			l << os.real_path(path)
+		}
+	}
+	collect(path, mut files, collect_fn)
+	for f in files {
+		contents := os.read_file(f) or { panic(err) }
+		lines := contents.split('\n')
+		if f.ends_with('_test.v') {
+			continue
+		}
+		mut info := []UndocumentedFN{}
+		for i, line in lines {
+			if line.starts_with('pub fn') ||
+				(line.starts_with('fn ') && !(line.starts_with('fn C.') || line.starts_with('fn main'))) {
+				// println('Match: $line')
+				if i > 0 && lines.len > 0 {
+					mut line_above := lines[i - 1]
+					if !line_above.starts_with('//') {
+						mut grab := true
+						for j := i - 2; j >= 0; j-- {
+							prev_line := lines[j]
+							if prev_line.contains('}') {
+								break
+							} else if prev_line.starts_with('[') {
+								continue
+							} else if prev_line.starts_with('//') {
+								grab = false
+								break
+							}
+						}
+						if grab {
+							clean_line := line.all_before_last(' {')
+							info << UndocumentedFN{i + 1, clean_line}
+						}
+					}
+				}
+			}
+		}
+		if info.len > 0 {
+			for undocumented_fn in info {
+				println('$f:$undocumented_fn.line:0:$undocumented_fn.signature')
+			}
+		}
+	}
+}
+
+fn main() {
+	if os.args.len == 1 {
+		println('Usage: missdoc PATH \nPrints all V functions in .v files under PATH/, that do not yet have documentation comments.')
+		exit(1)
+	}
+	for path in os.args[1..] {
+		report_undocumented_functions_in_path(path)
+	}
+}