Re: Invalid optimisation in _AS_PATH_WALK

[Andreas Schwab]

Akim Demaille <address@hidden> writes:

|> >>>>> "Andreas" == Andreas Schwab <address@hidden> writes:
|> 
|> Andreas> _AS_PATH_WALK always optimizes away $as_dummy if $1 contains
|> Andreas> variable references.  This is wrong.  Only the _result_ of an
|> Andreas> expansion is subject to field splitting.  Literal text is
|> Andreas> never split, even if it is part of the same word with
|> Andreas> expansions.
|> 
|> Thanks, I understand your point, but I'm unable to write an example
|> where it makes a difference.

This is from the standard Qt macros:

AC_PATH_PROG(MOC, moc moc2, /usr/bin/moc,
 
$ac_qt_bindir:$QTDIR/bin:$PATH:/usr/bin:/usr/X11R6/bin:/usr/lib/qt/bin:/usr/local/qt/bin)

Without the path it expands to this:

as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
for as_dir in 
$ac_qt_bindir:$QTDIR/bin:$PATH:/usr/bin:/usr/X11R6/bin:/usr/lib/qt/bin:/usr/local/qt/bin
....

and no field splitting is done on the literal colons.

Andreas.

-- 
Andreas Schwab, SuSE Labs, address@hidden
SuSE GmbH, Deutschherrnstr. 15-19, D-90429 Nürnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."