cproto generates function prototypes for functions defined in the specified C source files to the standard output. The function definitions may be in K&R or ANSI C style, or in the lint library form. cproto can also convert function definitions in the specified files from the K&R style to the ANSI C style.
YYAST is a library which completes Lex and Yacc by adding an Abstract Syntax Tree (AST). It is designed so that you write as little as code as possible in the Lex and Yacc grammar files, so that it doesn't distract from the grammar of the language, and is intended to make it easier to use high level programming languages for compilers.