#!/bin/sh

RE='[a-z]+\(\) {'
if grep -Eq "$RE" "$@"; then
	echo 'Functions with no argument without explicit "void" parameter:' >&2
	grep -En "$RE" "$@"
	exit 1
fi

awk '
/^[a-zA-Z0-9_]+.+{$/ && !/^static / {
	match($0, /[a-zA-Z0-9_]+\(/)
	fn_name = substr($0, RSTART, RLENGTH - 1)
	if (fn_name != "main") {
		header = substr(FILENAME, 0, length(FILENAME) - 1) "h"
		if (system("grep -qF \"" fn_name "(\" "  header)) {
			print "non-static function is not declared in a header:"
			printf "%s:%s:%s\n", FILENAME, FNR, $0
			exit 1
		}
	}
}
' "$@"