Re: [Qemu-devel] [PATCH RESEND] xen: limit pkg-config to PKG_CONFIG_PATH for xen libraries

[Juergen Gross]

On 24/03/17 18:20, Paul Durrant wrote:
> The Xen tools Makefile has been modified to set PKG_CONFIG_PATH such that
> use of pkg-config in QEMU configure finds the newly built Xen libraries.
> However, because older versions of Xen do not set PKG_CONFIG_PATH in the
> Makefile, the QEMU configure script will pick up any Xen libraries that may
> be installed in the build system rather than the newly built ones. Thus,
> if Xen 4.9 is built and installed it becomes impossible to build tools for
> an older version of Xen on the same system (without manual de-installtion).
> 
> This patch modifies configure to set PKG_CONFIG_LIBDIR to empty when
> looking for Xen libraries to ensure the search is limited only to
> PKG_CONFIG_PATH. This makes sure that, for versions of Xen prior to 4.9,
> pkg-config fails to find the Xen libraries an approriately falls back to
> previous methods of probing.
> 
> Signed-off-by: Paul Durrant <address@hidden>

NAK. You are breaking normal qemu build with installed Xen pkg-config
files.


Juergen

> ---
> Cc: Anthony Perard <address@hidden>
> Cc: Stefano Stabellini <address@hidden>
> Cc: Juergen Gross <address@hidden>
> ---
>  configure | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/configure b/configure
> index fdf47e4..6ef5980 100755
> --- a/configure
> +++ b/configure
> @@ -1974,6 +1974,10 @@ fi
>  ##########################################
>  # xen probe
>  
> +xen_query_pkg_config() {
> +    PKG_CONFIG_LIBDIR= ${pkg_config_exe} "$@"
> +}
> +
>  if test "$xen" != "no" ; then
>    xen_libs="-lxenstore -lxenctrl -lxenguest"
>    xen_stable_libs="-lxenforeignmemory -lxengnttab -lxenevtchn"
> @@ -1997,9 +2001,9 @@ EOF
>      xen=no
>  
>    # Xen version via pkg-config (Xen 4.9.0 and newer)
> -  elif $pkg_config --exists xencontrol ; then
> +  elif xen_query_pkg_config --exists xencontrol; then
>      xen_ctrl_version="$(printf '%d%02d%02d' \
> -      $($pkg_config --modversion xencontrol | sed 's/\./ /g') )"
> +      $(xen_query_pkg_config --modversion xencontrol | sed 's/\./ /g') )"
>      xen=yes
>  
>    elif
> @@ -2216,8 +2220,8 @@ EOF
>      if test $xen_ctrl_version -ge 40900 ; then
>        xen_pc="xencontrol xenstore xenguest xenforeignmemory xengnttab 
> xenevtchn"
>        xen_pc="$xen_pc xendevicemodel"
> -      xen_libs="$($pkg_config --libs $xen_pc)"
> -      QEMU_CFLAGS="$QEMU_CFLAGS $($pkg_config --cflags $xen_pc)"
> +      xen_libs="$(xen_query_pkg_config --libs $xen_pc)"
> +      QEMU_CFLAGS="$QEMU_CFLAGS $(xen_query_pkg_config --cflags $xen_pc)"
>      elif test $xen_ctrl_version -ge 40701 ; then
>        libs_softmmu="$xen_stable_libs $libs_softmmu"
>      fi
>