[PATCH] meson: move pixman detection to meson

[Paolo Bonzini]

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 skip the build of vhost-user-gpu when pixman is not installed or
too old.  Instead of adding CONFIG_PIXMAN, it is simpler to move the
detection to pixman.

Based on a patch by Thomas Huth. <thuth@redhat.com>

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: Paolo Bonzini <pbonzini@redhat.com>
---
 configure                          | 21 ++-------------------
 contrib/vhost-user-gpu/meson.build |  3 ++-
 meson.build                        | 12 +++++++-----
 3 files changed, 11 insertions(+), 25 deletions(-)

diff --git a/configure b/configure
index a5fa472c64..51b6164f69 100755
--- a/configure
+++ b/configure
@@ -3923,20 +3923,6 @@ if test "$modules" = yes; then
     fi
 fi
 
-##########################################
-# pixman support probe
-
-if test "$softmmu" = "no"; then
-  pixman_cflags=
-  pixman_libs=
-elif $pkg_config --atleast-version=0.21.8 pixman-1 > /dev/null 2>&1; then
-  pixman_cflags=$($pkg_config --cflags pixman-1)
-  pixman_libs=$($pkg_config --libs pixman-1)
-else
-  error_exit "pixman >= 0.21.8 not present." \
-      "Please install the pixman devel package."
-fi
-
 ##########################################
 # libmpathpersist probe
 
@@ -6649,8 +6635,8 @@ echo_version() {
     fi
 }
 
-# prepend pixman and ftd flags after all config tests are done
-QEMU_CFLAGS="$pixman_cflags $fdt_cflags $QEMU_CFLAGS"
+# prepend ftd flags after all config tests are done
+QEMU_CFLAGS="$fdt_cflags $QEMU_CFLAGS"
 QEMU_LDFLAGS="$fdt_ldflags $QEMU_LDFLAGS"
 
 config_host_mak="config-host.mak"
@@ -8053,9 +8039,6 @@ fi
 
 done # for target in $targets
 
-echo "PIXMAN_CFLAGS=$pixman_cflags" >> $config_host_mak
-echo "PIXMAN_LIBS=$pixman_libs" >> $config_host_mak
-
 if [ "$fdt" = "git" ]; then
   subdirs="$subdirs dtc"
 fi
diff --git a/contrib/vhost-user-gpu/meson.build 
b/contrib/vhost-user-gpu/meson.build
index 8df4c13bc5..7d9b29da8b 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 pixman.found()
   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 bcd39b39da..57c2fe2b65 100644
--- a/meson.build
+++ b/meson.build
@@ -114,8 +114,11 @@ 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 have_system or have_tools
+  pixman = dependency('pixman', required: have_system, version:'>=0.21.8',
+                      static: enable_static)
+endif
 pam = not_found
 if 'CONFIG_AUTH_PAM' in config_host
   pam = cc.find_library('pam')
@@ -1094,9 +1097,7 @@ 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
@@ -1303,6 +1304,7 @@ 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':            pixman.found()}
 # TODO: add back version
 summary_info += {'VTE support':       config_host.has_key('CONFIG_VTE')}
 summary_info += {'TLS priority':      config_host['CONFIG_TLS_PRIORITY']}
-- 
2.26.2