Re: [Qemu-devel] [PATCH v2] configure: use pkg-config for obtaining xen version

[Paul Durrant <Paul.Durrant@citrix.com>]

> -----Original Message-----
> From: Juergen Gross [mailto:jgross@suse.com]
> Sent: 27 March 2017 08:43
> To: qemu-devel@nongnu.org; xen-devel@lists.xenproject.org
> Cc: Anthony Perard <anthony.perard@citrix.com>; kraxel@redhat.com;
> sstabellini@kernel.org; Paul Durrant <Paul.Durrant@citrix.com>; Juergen
> Gross <jgross@suse.com>
> Subject: [PATCH v2] configure: use pkg-config for obtaining xen version
> 
> Instead of trying to guess the Xen version to use by compiling various
> test programs first just ask the system via pkg-config. Only if it
> can't return the version fall back to the test program scheme.
> 
> If configure is being called with dedicated flags for the Xen libraries
> use those instead of the pkg-config output. This will avoid breaking
> an in-tree Xen build of an old Xen version while a new Xen version is
> installed on the build machine: pkg-config would pick up the installed
> Xen config files as the Xen tree wouldn't contain any of them.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
> V2: - use pkg-config only if no Xen library paths have been specified via
>       --extra-ldflags
>     - keep test program for detecting Xen 4.9

This all looks plausible but it doesn't seem to be working for me when trying to build 4.8. I'm still getting a xen ctrl version of 40900... still trying to figure out why.

Also, the whitespace changes later on in the patch should probably be split out.

  Paul

> ---
>  configure | 155 ++++++++++++++++++++++++++++++++++--------------------
> --------
>  1 file changed, 86 insertions(+), 69 deletions(-)
> 
> diff --git a/configure b/configure
> index aabf098..c34b025 100755
> --- a/configure
> +++ b/configure
> @@ -1962,30 +1962,46 @@ fi
>  # xen probe
> 
>  if test "$xen" != "no" ; then
> -  xen_libs="-lxenstore -lxenctrl -lxenguest"
> -  xen_stable_libs="-lxenforeignmemory -lxengnttab -lxenevtchn"
> +  # Check whether Xen library path is specified via --extra-ldflags to avoid
> +  # overriding this setting with pkg-config output. If not, try pkg-config
> +  # to obtain all needed flags.
> 
> -  # First we test whether Xen headers and libraries are available.
> -  # If no, we are done and there is no Xen support.
> -  # If yes, more tests are run to detect the Xen version.
> +  if ! echo $EXTRA_LDFLAGS | grep tools/libxc > /dev/null && \
> +     $pkg_config --exists xencontrol ; then
> +    xen_ctrl_version="$(printf '%d%02d%02d' \
> +      $($pkg_config --modversion xencontrol | sed 's/\./ /g') )"
> +    xen=yes
> +    xen_pc="xencontrol xenstore xenguest xenforeignmemory xengnttab"
> +    xen_pc="$xen_pc xenevtchn xendevicemodel"
> +    QEMU_CFLAGS="$QEMU_CFLAGS $($pkg_config --cflags $xen_pc)"
> +    libs_softmmu="$($pkg_config --libs $xen_pc) $libs_softmmu"
> +    LDFLAGS="$($pkg_config --libs $xen_pc) $LDFLAGS"
> +  else
> 
> -  # Xen (any)
> -  cat > $TMPC <<EOF
> +    xen_libs="-lxenstore -lxenctrl -lxenguest"
> +    xen_stable_libs="-lxenforeignmemory -lxengnttab -lxenevtchn"
> +
> +    # First we test whether Xen headers and libraries are available.
> +    # If no, we are done and there is no Xen support.
> +    # If yes, more tests are run to detect the Xen version.
> +
> +    # Xen (any)
> +    cat > $TMPC <<EOF
>  #include <xenctrl.h>
>  int main(void) {
>    return 0;
>  }
>  EOF
> -  if ! compile_prog "" "$xen_libs" ; then
> -    # Xen not found
> -    if test "$xen" = "yes" ; then
> -      feature_not_found "xen" "Install xen devel"
> -    fi
> -    xen=no
> +    if ! compile_prog "" "$xen_libs" ; then
> +      # Xen not found
> +      if test "$xen" = "yes" ; then
> +        feature_not_found "xen" "Install xen devel"
> +      fi
> +      xen=no
> 
> -  # Xen unstable
> -  elif
> -      cat > $TMPC <<EOF &&
> +    # Xen unstable
> +    elif
> +        cat > $TMPC <<EOF &&
>  #undef XC_WANT_COMPAT_DEVICEMODEL_API
>  #define __XEN_TOOLS__
>  #include <xendevicemodel.h>
> @@ -1998,13 +2014,13 @@ int main(void) {
>    return 0;
>  }
>  EOF
> -      compile_prog "" "$xen_libs $xen_stable_libs -lxendevicemodel"
> -    then
> -    xen_stable_libs="$xen_stable_libs -lxendevicemodel"
> -    xen_ctrl_version=40900
> -    xen=yes
> -  elif
> -      cat > $TMPC <<EOF &&
> +        compile_prog "" "$xen_libs $xen_stable_libs -lxendevicemodel"
> +      then
> +      xen_stable_libs="$xen_stable_libs -lxendevicemodel"
> +      xen_ctrl_version=40900
> +      xen=yes
> +    elif
> +        cat > $TMPC <<EOF &&
>  /*
>   * If we have stable libs the we don't want the libxc compat
>   * layers, regardless of what CFLAGS we may have been given.
> @@ -2054,12 +2070,12 @@ int main(void) {
>    return 0;
>  }
>  EOF
> -      compile_prog "" "$xen_libs $xen_stable_libs"
> -    then
> -    xen_ctrl_version=40800
> -    xen=yes
> -  elif
> -      cat > $TMPC <<EOF &&
> +        compile_prog "" "$xen_libs $xen_stable_libs"
> +      then
> +      xen_ctrl_version=40800
> +      xen=yes
> +    elif
> +        cat > $TMPC <<EOF &&
>  /*
>   * If we have stable libs the we don't want the libxc compat
>   * layers, regardless of what CFLAGS we may have been given.
> @@ -2105,12 +2121,12 @@ int main(void) {
>    return 0;
>  }
>  EOF
> -      compile_prog "" "$xen_libs $xen_stable_libs"
> -    then
> -    xen_ctrl_version=40701
> -    xen=yes
> -  elif
> -      cat > $TMPC <<EOF &&
> +        compile_prog "" "$xen_libs $xen_stable_libs"
> +      then
> +      xen_ctrl_version=40701
> +      xen=yes
> +    elif
> +        cat > $TMPC <<EOF &&
>  #include <xenctrl.h>
>  #include <stdint.h>
>  int main(void) {
> @@ -2120,14 +2136,14 @@ int main(void) {
>    return 0;
>  }
>  EOF
> -      compile_prog "" "$xen_libs"
> -    then
> -    xen_ctrl_version=40700
> -    xen=yes
> +        compile_prog "" "$xen_libs"
> +      then
> +      xen_ctrl_version=40700
> +      xen=yes
> 
> -  # Xen 4.6
> -  elif
> -      cat > $TMPC <<EOF &&
> +    # Xen 4.6
> +    elif
> +        cat > $TMPC <<EOF &&
>  #include <xenctrl.h>
>  #include <xenstore.h>
>  #include <stdint.h>
> @@ -2148,14 +2164,14 @@ int main(void) {
>    return 0;
>  }
>  EOF
> -      compile_prog "" "$xen_libs"
> -    then
> -    xen_ctrl_version=40600
> -    xen=yes
> +        compile_prog "" "$xen_libs"
> +      then
> +      xen_ctrl_version=40600
> +      xen=yes
> 
> -  # Xen 4.5
> -  elif
> -      cat > $TMPC <<EOF &&
> +    # Xen 4.5
> +    elif
> +        cat > $TMPC <<EOF &&
>  #include <xenctrl.h>
>  #include <xenstore.h>
>  #include <stdint.h>
> @@ -2175,13 +2191,13 @@ int main(void) {
>    return 0;
>  }
>  EOF
> -      compile_prog "" "$xen_libs"
> -    then
> -    xen_ctrl_version=40500
> -    xen=yes
> +        compile_prog "" "$xen_libs"
> +      then
> +      xen_ctrl_version=40500
> +      xen=yes
> 
> -  elif
> -      cat > $TMPC <<EOF &&
> +    elif
> +        cat > $TMPC <<EOF &&
>  #include <xenctrl.h>
>  #include <xenstore.h>
>  #include <stdint.h>
> @@ -2200,24 +2216,25 @@ int main(void) {
>    return 0;
>  }
>  EOF
> -      compile_prog "" "$xen_libs"
> -    then
> -    xen_ctrl_version=40200
> -    xen=yes
> +        compile_prog "" "$xen_libs"
> +      then
> +      xen_ctrl_version=40200
> +      xen=yes
> 
> -  else
> -    if test "$xen" = "yes" ; then
> -      feature_not_found "xen (unsupported version)" \
> -                        "Install a supported xen (xen 4.2 or newer)"
> +    else
> +      if test "$xen" = "yes" ; then
> +        feature_not_found "xen (unsupported version)" \
> +                          "Install a supported xen (xen 4.2 or newer)"
> +      fi
> +      xen=no
>      fi
> -    xen=no
> -  fi
> 
> -  if test "$xen" = yes; then
> -    if test $xen_ctrl_version -ge 40701  ; then
> -      libs_softmmu="$xen_stable_libs $libs_softmmu"
> +    if test "$xen" = yes; then
> +      if test $xen_ctrl_version -ge 40701  ; then
> +        libs_softmmu="$xen_stable_libs $libs_softmmu"
> +      fi
> +      libs_softmmu="$xen_libs $libs_softmmu"
>      fi
> -    libs_softmmu="$xen_libs $libs_softmmu"
>    fi
>  fi
> 
> --
> 2.10.2