Re: unoptimized autoconf generated code

[Eric Blake]

According to Ralf Wildenhues on 3/4/2010 1:23 PM:
> 
> Why not let AS_LITERAL_IF retain the semantics that you intend for
> AS_LITERAL_IF_W?  Would seem logical to me.  You can add a new macro
> AS_LITERAL_WORD_IF that has the semantics of your AS_LITERAL_IF and use
> that whereever appropriate in Autoconf macros.  Your call.

Definitely nicer names.  Yes, I'll respin along those lines, so that
AS_LITERAL_IF doesn't have quite the semantics churn.

> 
> I accidentally applied your AS_LITERAL_IF patch without the AS_BOX
> "optimization" and got lots of test failures that way.

Yes, the AS_BOX change is directly a result of AS_LITERAL_IF (as written
in patch 2/3) no longer accepting whitespace.  But I'm not sure why
changing AS_LITERAL_IF without changing AS_BOX would lead to testsuite
failures; I'll repeat your experiment, and make sure I'm not overlooking
something else important.

>  So the latter
> isn't only an optimization, and the former has the potential to break
> user code; as AS_BOX wasn't documented until now, users would have to
> reimplement it, possibly using the exact code that the old AS_BOX had.
> AS_BOX and m4_text_box are not tested in the testsuite BTW.

m4_text_box is tested if AS_BOX is tested.  And AS_BOX was indirectly
"tested" - since autotest/general.m4 uses AS_BOX, all testsuites end up
containing expansions of that macro; and the fact that we test autotest
means... well, you get it.

But yes, I need to add an explicit m4_text_box test to the testsuite.

-- 
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org

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