New file.

diff --git a/etc/check-subrs.rb b/etc/check-subrs.rb
new file mode 100755 (executable)
index 0000000..a477792
--- /dev/null
+++ b/etc/check-subrs.rb
@@ -0,0 +1,60 @@
+#! /usr/bin/env ruby
+
+# This script loosely checks:
+# - Macros used before they are defined
+# - Non-command functions which may never be used
+
+# To run,
+# $ for i in liece-[a-z]*.el; ../etc/check-subrs.rb $i *.el~$i
+
+def scan_inlines(data)
+  result = []
+  data.scan(/^\((?:defmacro|defsubst)\s+(\S+)/) {|name,|
+    pos = Regexp.last_match.begin(1)
+    result << [pos, name]
+  }
+  result
+end
+
+def scan_subrs(data)
+  result = []
+  data.scan(/^\(defun\s+(\S+)\s*\([^\)]*\)\s*\
+((?:"[^"]*")?\s*\(interactive\b)?/) {|name, i|
+    pos = Regexp.last_match.begin(1)
+    result << [pos, name] unless i
+  }
+  result
+end
+
+def count_call(name, data)
+  count = 0
+  data.scan(/\b#{name}\b/) {
+    count += 1
+  }
+  count
+end
+
+symbols = []
+File.open(ARGV[0]) {|file|
+  data = file.read
+  symbols = scan_inlines(data)
+  symbols.each {|pos, name|
+    if /\b#{name}\b/ && Regexp.last_match.begin(0) < pos
+      puts("#{name} is called before its definition")
+    end
+  }
+  symbols |= scan_subrs(data)
+}
+
+symbols.each {|pos, name|
+  count = 0
+  ARGV.each {|source|
+    File.open(source) {|file|
+      data = file.read
+      count += count_call(name, data)
+    }
+  }
+  if count < 2
+    puts("#{name} may not be called")
+  end
+}