configure, meson: convert libxml2 detection to meson

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -425,7 +425,7 @@ vdi=${default_feature:-yes}
 vvfat=${default_feature:-yes}
 qed=${default_feature:-yes}
 parallels=${default_feature:-yes}
-libxml2="$default_feature"
+libxml2="auto"
 debug_mutex="no"
 libpmem="auto"
 default_devices="true"
@@ -1419,9 +1419,9 @@ for opt do
   ;;
   --enable-numa) numa="yes"
   ;;
-  --disable-libxml2) libxml2="no"
+  --disable-libxml2) libxml2="disabled"
   ;;
-  --enable-libxml2) libxml2="yes"
+  --enable-libxml2) libxml2="enabled"
   ;;
   --disable-tcmalloc) tcmalloc="no"
   ;;
@@ -3409,21 +3409,6 @@ EOF
   fi
 fi
 
-##########################################
-# libxml2 probe
-if test "$libxml2" != "no" ; then
-    if $pkg_config --exists libxml-2.0; then
-        libxml2="yes"
-        libxml2_cflags=$($pkg_config --cflags libxml-2.0)
-        libxml2_libs=$($pkg_config --libs libxml-2.0)
-    else
-        if test "$libxml2" = "yes"; then
-            feature_not_found "libxml2" "Install libxml2 devel"
-        fi
-        libxml2="no"
-    fi
-fi
-
 # Check for inotify functions when we are building linux-user
 # emulator.  This is done because older glibc versions don't
 # have syscall stubs for these implemented.  In that case we
@@ -5636,12 +5621,6 @@ if test "$have_rtnetlink" = "yes" ; then
   echo "CONFIG_RTNETLINK=y" >> $config_host_mak
 fi
 
-if test "$libxml2" = "yes" ; then
-  echo "CONFIG_LIBXML2=y" >> $config_host_mak
-  echo "LIBXML2_CFLAGS=$libxml2_cflags" >> $config_host_mak
-  echo "LIBXML2_LIBS=$libxml2_libs" >> $config_host_mak
-fi
-
 if test "$replication" = "yes" ; then
   echo "CONFIG_REPLICATION=y" >> $config_host_mak
 fi
@@ -6050,7 +6029,7 @@ if test "$skip_meson" = no; then
         -Dcapstone=$capstone -Dslirp=$slirp -Dfdt=$fdt -Dbrlapi=$brlapi \
         -Dcurl=$curl -Dglusterfs=$glusterfs -Dbzip2=$bzip2 -Dlibiscsi=$libiscsi \
         -Dlibnfs=$libnfs -Diconv=$iconv -Dcurses=$curses -Dlibudev=$libudev\
-        -Drbd=$rbd -Dlzo=$lzo -Dsnappy=$snappy -Dlzfse=$lzfse \
+        -Drbd=$rbd -Dlzo=$lzo -Dsnappy=$snappy -Dlzfse=$lzfse -Dlibxml2=$libxml2 \
         -Dlibdaxctl=$libdaxctl -Dlibpmem=$libpmem -Dlinux_io_uring=$linux_io_uring \
         -Dgnutls=$gnutls -Dnettle=$nettle -Dgcrypt=$gcrypt -Dauth_pam=$auth_pam \
         -Dzstd=$zstd -Dseccomp=$seccomp -Dvirtfs=$virtfs -Dcap_ng=$cap_ng \

meson.build

@@ -334,9 +334,9 @@ if not get_option('linux_io_uring').auto() or have_block
                               method: 'pkg-config', kwargs: static_kwargs)
 endif
 libxml2 = not_found
-if 'CONFIG_LIBXML2' in config_host
-  libxml2 = declare_dependency(compile_args: config_host['LIBXML2_CFLAGS'].split(),
-                               link_args: config_host['LIBXML2_LIBS'].split())
+if not get_option('libxml2').auto() or have_block
+  libxml2 = dependency('libxml-2.0', required: get_option('libxml2'),
+                       method: 'pkg-config', kwargs: static_kwargs)
 endif
 libnfs = not_found
 if not get_option('libnfs').auto() or have_block
@@ -2821,7 +2821,7 @@ summary_info += {'bzip2 support':     libbzip2.found()}
 summary_info += {'lzfse support':     liblzfse.found()}
 summary_info += {'zstd support':      zstd.found()}
 summary_info += {'NUMA host support': config_host.has_key('CONFIG_NUMA')}
-summary_info += {'libxml2':           config_host.has_key('CONFIG_LIBXML2')}
+summary_info += {'libxml2':           libxml2.found()}
 summary_info += {'capstone':          capstone_opt == 'disabled' ? false : capstone_opt}
 summary_info += {'libpmem support':   libpmem.found()}
 summary_info += {'libdaxctl support': libdaxctl.found()}

meson_options.txt

@@ -92,6 +92,8 @@ option('libudev', type : 'feature', value : 'auto',
        description: 'Use libudev to enumerate host devices')
 option('libusb', type : 'feature', value : 'auto',
        description: 'libusb support for USB passthrough')
+option('libxml2', type : 'feature', value : 'auto',
+       description: 'libxml2 support for Parallels image format')
 option('linux_io_uring', type : 'feature', value : 'auto',
        description: 'Linux io_uring support')
 option('lzfse', type : 'feature', value : 'auto',