Re: [PATCH][RFC] -Wno-... option to suppress builtin macro redefined warnings

[Tom Tromey <tromey@redhat.com>]

>>>>> "Simon" == Simon Baldwin <simonb@google.com> writes:

Simon> This patch adds a warning suppression flag,
Simon> -Wno-builtin-macro-redefined, to silence gcc warnings where
Simon> builtin macros such as __TIME__ are undefined or redefined,
Simon> either on the command line or by directives.

This seems like a reasonable thing to want to do.

Simon> Thoughts, comments, suggestions?  Aimed at trunk.  Thanks.

The libcpp bits look generally ok.

However, it seems to me that we would want to allow redefinition of
some macros (__TIME__ et al) but not others (e.g., __LINE__).

So, how about splitting builtin_array into two pieces (and just FYI,
there's a comment above referring to "two tables" that should be
changed) and then unconditionally setting NODE_WARN for one table but
not the other?  Or, just adding a special case in the builtin
definition loop for the BT_* constants we care to allow?

Tom