Re: [Qemu-devel] [PATCH] configure: Use strings command from cross development tools

[Eric Blake <eblake@redhat.com>]

On 05/13/2018 03:50 AM, Stefan Weil wrote:
> This fixes cross builds for the (rare) case where cross binutils
> but no native binutils are installed.
> 
> Signed-off-by: Stefan Weil <sw@weilnetz.de>
> ---
>   configure | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 

> +strings="${STRINGS-${cross_prefix}strings}"
>   strip="${STRIP-${cross_prefix}strip}"

Hmm - we have pre-existing problems in our configure file.  More on that 
below...

>   windres="${WINDRES-${cross_prefix}windres}"
>   pkg_config_exe="${PKG_CONFIG-${cross_prefix}pkg-config}"
> @@ -1956,9 +1957,9 @@ int main(int argc, char *argv[]) {
>   EOF
>   
>   if compile_object ; then
> -    if strings -a $TMPO | grep -q BiGeNdIaN ; then
> +    if "$strings" -a $TMPO | grep -q BiGeNdIaN ; then

I'd much prefer this to be:

if $strings -a $TMPO | grep...

That's because if I have something like this in my environment:

STRINGS='/path/to/strings -a'

it will only work if you allow word splitting on my variable.

...having said that, here's the pre-existing problem with user 
replacement tools that contain whitespace:

if test "$strip_opt" = "yes" ; then
   echo "STRIP=${strip}" >> $config_host_mak
fi

we are improperly quoting the whitespace when populating 
$config_host_mak, and therefore could end up attempting to execute the 
user's first argument as a standalone command, rather than the intended 
result of assigning a two-word command to a single variable.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org