[PATCH] configure / meson: Fix building with --disable-system and virglrenderer

[Thomas Huth]

When pixman is not installed (or too old), but virglrenderer is available
and "configure" has been run with "--disable-system", the build currently
aborts when trying to compile vhost-user-gpu (since it requires pixman).
Let's add a proper CONFIG_PIXMAN switch so we can skip the build of
vhost-user-gpu when pixman is not installed or too old.

Fixes: 9b52b17ba5 ("configure: Allow to build tools without pixman")
Reported-by: Rafael Kitover <rkitover@gmail.com>
Reported-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 configure                          | 20 +++++++++++++-------
 contrib/vhost-user-gpu/meson.build |  3 ++-
 meson.build                        | 12 +++++++-----
 3 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/configure b/configure
index b1e11397a8..bddda91477 100755
--- a/configure
+++ b/configure
@@ -3925,15 +3925,18 @@ fi
 ##########################################
 # pixman support probe
 
-if test "$softmmu" = "no"; then
-  pixman_cflags=
-  pixman_libs=
-elif $pkg_config --atleast-version=0.21.8 pixman-1 > /dev/null 2>&1; then
+if $pkg_config --atleast-version=0.21.8 pixman-1 > /dev/null 2>&1; then
+  pixman="yes"
   pixman_cflags=$($pkg_config --cflags pixman-1)
   pixman_libs=$($pkg_config --libs pixman-1)
 else
+  pixman="no"
+  pixman_cflags=
+  pixman_libs=
+fi
+if test "$softmmu" = "yes" && test "$pixman" = "no"; then
   error_exit "pixman >= 0.21.8 not present." \
-      "Please install the pixman devel package."
+      "Please install the pixman devel package or use --disable-system."
 fi
 
 ##########################################
@@ -8054,8 +8057,11 @@ fi
 
 done # for target in $targets
 
-echo "PIXMAN_CFLAGS=$pixman_cflags" >> $config_host_mak
-echo "PIXMAN_LIBS=$pixman_libs" >> $config_host_mak
+if test "$pixman" = "yes"; then
+  echo "CONFIG_PIXMAN=y" >> $config_host_mak
+  echo "PIXMAN_CFLAGS=$pixman_cflags" >> $config_host_mak
+  echo "PIXMAN_LIBS=$pixman_libs" >> $config_host_mak
+fi
 
 if [ "$fdt" = "git" ]; then
   subdirs="$subdirs dtc"
diff --git a/contrib/vhost-user-gpu/meson.build 
b/contrib/vhost-user-gpu/meson.build
index 6c1459f54a..142daebfd7 100644
--- a/contrib/vhost-user-gpu/meson.build
+++ b/contrib/vhost-user-gpu/meson.build
@@ -1,5 +1,6 @@
 if 'CONFIG_TOOLS' in config_host and 'CONFIG_VIRGL' in config_host \
-    and 'CONFIG_GBM' in config_host and 'CONFIG_LINUX' in config_host
+    and 'CONFIG_GBM' in config_host and 'CONFIG_LINUX' in config_host \
+    and 'CONFIG_PIXMAN' in config_host
   executable('vhost-user-gpu', files('vhost-user-gpu.c', 'virgl.c', 'vugbm.c'),
              link_with: libvhost_user,
              dependencies: [qemuutil, pixman, gbm, virgl],
diff --git a/meson.build b/meson.build
index 7fbb7ab2fb..9eecea549c 100644
--- a/meson.build
+++ b/meson.build
@@ -113,8 +113,11 @@ if 'CONFIG_GNUTLS' in config_host
   gnutls = declare_dependency(compile_args: 
config_host['GNUTLS_CFLAGS'].split(),
                               link_args: config_host['GNUTLS_LIBS'].split())
 endif
-pixman = declare_dependency(compile_args: config_host['PIXMAN_CFLAGS'].split(),
-                            link_args: config_host['PIXMAN_LIBS'].split())
+pixman = not_found
+if 'CONFIG_PIXMAN' in config_host
+  pixman = declare_dependency(compile_args: 
config_host['PIXMAN_CFLAGS'].split(),
+                              link_args: config_host['PIXMAN_LIBS'].split())
+endif
 pam = not_found
 if 'CONFIG_AUTH_PAM' in config_host
   pam = cc.find_library('pam')
@@ -1095,9 +1098,7 @@ if have_tools
   if 'CONFIG_VHOST_USER' in config_host
     subdir('contrib/libvhost-user')
     subdir('contrib/vhost-user-blk')
-    if 'CONFIG_LINUX' in config_host
-      subdir('contrib/vhost-user-gpu')
-    endif
+    subdir('contrib/vhost-user-gpu')
     subdir('contrib/vhost-user-input')
     subdir('contrib/vhost-user-scsi')
   endif
@@ -1278,6 +1279,7 @@ summary_info += {'SDL image support': sdl_image.found()}
 # TODO: add back version
 summary_info += {'GTK support':       config_host.has_key('CONFIG_GTK')}
 summary_info += {'GTK GL support':    config_host.has_key('CONFIG_GTK_GL')}
+summary_info += {'pixman support':    config_host.has_key('CONFIG_PIXMAN')}
 # TODO: add back version
 summary_info += {'VTE support':       config_host.has_key('CONFIG_VTE')}
 summary_info += {'TLS priority':      config_host['CONFIG_TLS_PRIORITY']}
-- 
2.18.2