Added intern_ids.rb

Merged: https://github.com/ruby/ruby/pull/4684

defs/id.def

@@ -138,6 +138,21 @@ class KeywordError < RuntimeError
   end
 end
 
+def id2varname(token, prefix = nil)
+  if /#/ =~ token
+    token = "_#{token.gsub(/\W+/, '_')}"
+  else
+    token = token.sub(/\?/, 'P')
+    token = prefix + token if prefix
+    token.sub!(/\A[a-z]/) {$&.upcase}
+    token.sub!(/\A\$/, "_G_")
+    token.sub!(/\A@@/, "_C_")
+    token.sub!(/\A@/, "_I_")
+    token.gsub!(/\W+/, "")
+  end
+  token
+end
+
 predefined_ids = {}
 preserved_ids = []
 local_ids = []
@@ -153,16 +168,7 @@ predefined.split(/^/).each_with_index do |line, num|
   line.sub!(/\s+#.*/, '')
   name, token = line.split
   next unless name
-  token ||= name
+  token = id2varname(token || name)
-  if /#/ =~ token
-    token = "_#{token.gsub(/\W+/, '_')}"
-  else
-    token = token.sub(/\?/, 'P').sub(/\A[a-z]/) {$&.upcase}
-    token.sub!(/\A\$/, "_G_")
-    token.sub!(/\A@@/, "_C_")
-    token.sub!(/\A@/, "_I_")
-    token.gsub!(/\W+/, "")
-  end
   if name == '-'
     preserved_ids << token
     next

tool/intern_ids.rb

@@ -0,0 +1,35 @@
+#!/usr/bin/ruby -sp
+# $ ruby -i tool/intern_ids.rb -prefix=_ foo.c
+
+BEGIN {
+  $prefix ||= nil
+
+  defs = File.join(File.dirname(__dir__), "defs/id.def")
+  ids = eval(File.read(defs), binding, defs)
+  table = {}
+  ids[:predefined].each {|v, t| table[t] = "id#{v}"}
+  ids[:token_op].each {|v, t, *| table[t] = "id#{v}"}
+  predefined = table.keys
+}
+
+$_.gsub!(/rb_intern\("([^\"]+)"\)/) do
+  token = $1
+  table[token] ||= "id" + id2varname(token, $prefix)
+end
+
+END {
+  predefined.each {|t| table.delete(t)}
+  unless table.empty?
+    table = table.sort_by {|t, v| v}
+
+    # Append at the last, then edit and move appropriately.
+    puts
+    puts "==== defs"
+    table.each {|t, v| puts "static ID #{v};"}
+    puts ">>>>"
+    puts
+    puts "==== init"
+    table.each {|t, v|puts "#{v} = rb_intern_const(\"#{t}\");"}
+    puts ">>>>"
+  end
+}