Re: suppressing byte-compiler warnings about undefined functions

[Richard Stallman]

      > But that is not different from plain defvar, it just seems to add
      > a layer of obfuscation...

    In fact most cc-bytecomp-defvars are not useful. I removed all of them
    and recompiled. Only filladapt-*, c-syntactic-* and
    c-preprocessor-face-name got warnings.

The point is that (defvar foo) does the same job.
It turns off warnings only in the file it appears in.