[Bug preprocessor/38161] [4.4 regression] #elif <non-const expression #defined in this #if> breaks

[h dot b dot furuseth at usit dot uio dot no]

------- Comment #2 from h dot b dot furuseth at usit dot uio dot no  2008-11-17 20:15 -------
Subject: Re:  [4.4 regression] #elif <non-const expression #defined in this
#if> breaks

Yes, I should have read the #36320 text more carefully.  I merely
noticed that its empty #elif cannot expand to anything correct, while
my example can (and does in the real-life case which produced it).

I thought C99 6.10p7 was what saved it:
  The preprocessing tokens within a preprocessing directive are
  not subject to macro expansion unless otherwise stated.
but maybe not.  6.10.1p3 doesn't say anything about some #elif branches
not being evaluated:-(  Hopefully that's just overly standard-lawerly
though.  Maybe comp.std.c would have been a better place to ask.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38161