Re: Portability of preprocessor directives

[Paul Eggert]

Thomas Dickey <address@hidden> writes:

> HPUX 9.x's C compiler trashed files starting with an #elif
> (that's in the early 90's - within the scope of his request).

Thanks for mentioning that; I hadn't heard that one.  I found a
7-year-old bug report for CVS that mentions the same issue, for HP-UX
9.01, in <http://www.geocrawler.com/archives/3/383/1996/5/0/2114760/>.

It might be reasonable to suggest to the few remaining HP-UX 9 users
that they install a patch, assuming one is available.  Many
relatively-common applications assume #elif (e.g., coreutils, CVS,
OpenSSH/OpenSSL, Python) so this shouldn't be a new issue for the
remaining HP-UX 9 users.

As it happens, GNU make 3.80's main.c has an #elif in it, so if nobody
has complained about #elif for that version of GNU "make", it's an
indication that we don't need to worry about #elif in later versions.