Re: autoconf: AC_SYS_LARGEFILE should output to CPPFLAGS

[Zack Weinberg]

On Wed, Jan 25, 2017 at 12:21 PM, Thorsten Glaser <address@hidden> wrote:
>
> Would you at least *consider* moving the definition back to some
> command line argument? (Changing severity to wishlist now; if not,
> we can likely close the bug, but I’d still like you to please at
> least consider doing the change.)

As far as I can tell from the Git history, AC_SYS_LARGEFILE has
*always* used AC_DEFINE_UNQUOTED to define the various preprocessor
macros that it can define (_FILE_OFFSET_BITS, _LARGE_FILES, and
_DARWIN_USE_64_BIT_INODE).  That part of the code has been unchanged
since AC_SYS_LARGEFILE was added to specific.m4.

I can see how you got the impression from the documentation that these
are added to CC instead, but that's actually talking about a different
thing that AC_SYS_LARGEFILE can do -- on *one* system, namely IRIX 6,
it may try adding "-n32" to CC.  As a general rule, whenever the
Autoconf manual says that something defines preprocessor macros, you
can assume that it does that with AC_DEFINE(_UNQUOTED).

You're talking about this like it's a regression.  Can you please
verify that it really was an Autoconf upgrade that broke the build of
whatever program you're having trouble with, and if so, report what
the older version was?

zw