Re: AC_INIT seems to be setting CXXFLAGS

[Paolo Bonzini]

> Actually, it's that I can't override these in a default build by any
> mechanism other than editing CXXFLAGS, which is listed as something that
> autoconf scripts are not to do.

The intended meaning of "are not to do" is that the user should always 
be able to override CFLAGS and CXXFLAGS.  In other words, autoconf 
scripts should never place in CFLAGS and CXXFLAGS any option that, if 
removed, will cause the build to fail.  The typical example are -D and 
-I options, or in the case of GCC options like -fpermissive (which would 
presumably cause parse errors if eliminated) or -msse (without which SSE 
builtins won't work).

> So I'm left doing what I posted earlier and setting CXXFLAGS to "" if
> the user hasn't set it at ./configure time, since there is no other
> option to say "hey, um, thanks! but I don't really want you to add -g
> -O2 to my flags"

That's okay.  Doing simply

: ${CXXFLAGS=""}

right after AC_INIT is fine.  So is setting CXXFLAGS to "-O1 -g" if your 
program doesn't like being compiled at -O2.

I'm not a native speaker (and the only native-speaking Autoconf 
developer is gone for two weeks), so suggestions on how to phrase this 
in the documentation are very welcome.

Paolo