'Rules/C.pm'
This is a PBS (Perl Build System) module.
When is 'Rules/C.pm' used?
Whenever we need to build object files from c, cpp or assembler source.
What 'Rules/C.pm' does.
Add a C depender Rule in your Pbsfile
define the variable C_DEFINES if not already defined and make all object file depend on it
define the variable CFLAGS_INCLUDE if not already defined
tag cpp, c, header, assembler , library, ... files as source only
Adds the rules for building objects files
Adds a meta rule to arbiter between different types of source code