I have written a small structure (function_cfg_info) to hold CFG information (defined in new file tree-cfg.h) and wanted to add this to call graph node data structure (in cgraph.h).
This list isn't for people trying to learn how to write C code. It is for people trying to work on gcc development. There are better places to ask beginner questions, such as gcc-help.
You should also read the instructions on reporting bugs. You didn't include the error message you got. You also apparently didn't include a full example, as you claim that you included tree-cfg.h, but there is no #include in your example. It should work with the missing #include. See
http://gcc.gnu.org/bugs.html
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com