Re: A plan to remove CUMULATIVE_ARGS [was: Re: RFA: PR44566: accessor macros (1/3): CUMULATIVE_ARGS]

[Joern Rennecke <amylaar at spamcop dot net>]

Quoting Nathan Froyd <froydnj@codesourcery.com>:

> Yes, we agree here, but I must be dense, because I can't tell what
> changes that you think I would make that make it target-dependent.
> Could you please provide examples of such changes?  Just for
> clarification: I'm talking about making hooks that take/return pointers
> to CUMULATIVE_ARGS, *not* the actual CUMULATIVE_ARGS structure.

If you declare it as CUMULATIVE_ARGS *, then alias analysis is entitled to
think that this can't be anything but the CUMULATIVE_ARGS that it is
currently seeing.  A compiler is even entitled to have different kinds  
of pointers dependent on the data type pointed to - although gcc  
doesn't do
this (for now?).

If you declare it as void * - or something typedef'ed to void * - than this
problem does not arise.