Re: [XEN PATCH 1/2] tools/python: Fix install-wrap

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

On Tue, May 19, 2020 at 09:58:15AM +0100, Wei Liu wrote:
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> On Wed, Mar 11, 2020 at 05:59:32PM +0000, Anthony PERARD wrote:
> > This allows to use install-wrap when the source scripts is in a
> > subdirectory.
> > 
> > Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
> > ---
> >  tools/python/install-wrap | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/tools/python/install-wrap b/tools/python/install-wrap
> > index 00e2014016f9..fef24e01708d 100755
> > --- a/tools/python/install-wrap
> > +++ b/tools/python/install-wrap
> > @@ -44,7 +44,7 @@ shift
> >  destf="$dest"
> >  for srcf in ${srcs}; do
> >     if test -d "$dest"; then
> > -           destf="$dest/${srcf%%*/}"
> > +           destf="$dest/${srcf##*/}"
> 
> This seems to have changed the pattern from "Remove Largest Suffix" to
> "Remove Largest Prefix".
> 
> What does it do in practice?
> 
> For POSIX sh
> 
> x=posix/src/std
> echo ${x%%*/} -> posix/src/std
> echo ${x##*/} -> std
> 
> I would think the former is what you want. But I could be missing
> something obvious.

The former is a noop. It's the same as not doing anything.

Unless x="dir/dir/" and in that case, the %% would remove everything,
resulting in an empty string.

$srcf contains the path to where the script which we want to install is,
which is a relative path from where the ./install-wrap is executed from.
$destf is the final destination of the script, but if $dest is a
directory, then ./install-wrap wants to install the script in $dest, not
in some sub-directory of it. ./install-wrap doesn't handle this
sub-directory it fails to execute when there is one. (It's probably the
$install that failed to copy $srcf in a non-existing directory.)

This from the next patch is probably where things fails
    $(INSTALL_PYTHON_PROG) scripts/convert-legacy-stream 
$(DESTDIR)$(LIBEXEC_BIN)

-- 
Anthony PERARD