GNM, Programming, Generate Messages and SDML documentation GNM V2.4-000 GNM is a compiler that permits you to generate both MESSAGE files (.MSG files) and DOCUMENT SDML files containing the error messages and recovery text. From the MESSAGE compiler, you can also get the SDL output (MESSAGE/SDL), and from that the language-specific include files containing the message definitions. GNM is built on lib$table_parse for its baseline operations, and for its grammar. Also included here are tsearch routines, C binary tree routines.