- The php_stdlib/ was generated by:

      $ pfff_test -generate_php_stdlib /path/to/hphp/src/idl/ /path/to/phpdoc/ data/php_stdlib
      $ cp /path/to/hphp/system/classes/*.php data/php_stdlib/

  All the builtins_xxx files were generated from .idl files coming
  from HPHP. See analyze_php/builtins_php.ml.
  update: some idl files are now under hphp/facebook/extensions/
  A few files were added manually for constants/functions/classes
  not specified in HPHP system files or special constants
  defined only in pfff.

  Don't forget to copy this directory in the project you want to analyze
  and update such a directory when you update the list of builtins.
  
  You can also manually patch things with:

      $ pfff_test -builtin_of_idl /path/to/one/idl/file.php
      
- The pleac_php/ was generated by:

   $ ./pfff_db_light -lang php -output_dir data/php_pleac -gen_pleac ~/software-src/pleac/

  See h_program-lang/pleac.ml