cap_ng: convert to meson

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -330,7 +330,7 @@ xen_ctrl_version="$default_feature"
 xen_pci_passthrough="auto"
 linux_aio="$default_feature"
 linux_io_uring="$default_feature"
-cap_ng="$default_feature"
+cap_ng="auto"
 attr="$default_feature"
 libattr="$default_feature"
 xfs="$default_feature"
@@ -1122,9 +1122,9 @@ for opt do
   ;;
   --enable-tcg-interpreter) tcg_interpreter="yes"
   ;;
-  --disable-cap-ng)  cap_ng="no"
+  --disable-cap-ng)  cap_ng="disabled"
   ;;
-  --enable-cap-ng) cap_ng="yes"
+  --enable-cap-ng) cap_ng="enabled"
   ;;
   --disable-tcg) tcg="disabled"
   ;;
@@ -3192,28 +3192,6 @@ EOF
   fi
 fi
 
-##########################################
-# libcap-ng library probe
-if test "$cap_ng" != "no" ; then
-  cap_libs="-lcap-ng"
-  cat > $TMPC << EOF
-#include <cap-ng.h>
-int main(void)
-{
-    capng_capability_to_name(CAPNG_EFFECTIVE);
-    return 0;
-}
-EOF
-  if compile_prog "" "$cap_libs" ; then
-    cap_ng=yes
-  else
-    if test "$cap_ng" = "yes" ; then
-      feature_not_found "cap_ng" "Install libcap-ng devel"
-    fi
-    cap_ng=no
-  fi
-fi
-
 ##########################################
 # Sound support libraries probe
 
@@ -5702,10 +5680,6 @@ fi
 if test "$gprof" = "yes" ; then
   echo "CONFIG_GPROF=y" >> $config_host_mak
 fi
-if test "$cap_ng" = "yes" ; then
-  echo "CONFIG_LIBCAP_NG=y" >> $config_host_mak
-  echo "LIBCAP_NG_LIBS=$cap_libs" >> $config_host_mak
-fi
 echo "CONFIG_AUDIO_DRIVERS=$audio_drv_list" >> $config_host_mak
 for drv in $audio_drv_list; do
     def=CONFIG_AUDIO_$(echo $drv | LC_ALL=C tr '[a-z]' '[A-Z]')
@@ -6603,7 +6577,7 @@ NINJA=$ninja $meson setup \
         -Dcurl=$curl -Dglusterfs=$glusterfs -Dbzip2=$bzip2 -Dlibiscsi=$libiscsi \
         -Dlibnfs=$libnfs -Diconv=$iconv -Dcurses=$curses -Dlibudev=$libudev\
         -Drbd=$rbd -Dlzo=$lzo -Dsnappy=$snappy -Dlzfse=$lzfse \
-        -Dzstd=$zstd -Dseccomp=$seccomp -Dvirtfs=$virtfs \
+        -Dzstd=$zstd -Dseccomp=$seccomp -Dvirtfs=$virtfs -Dcap_ng=$cap_ng \
         -Ddocs=$docs -Dsphinx_build=$sphinx_build -Dinstall_blobs=$blobs \
         -Dvhost_user_blk_server=$vhost_user_blk_server \
         -Dfuse=$fuse -Dfuse_lseek=$fuse_lseek \

meson.build

@@ -338,10 +338,28 @@ if not get_option('seccomp').auto() or have_system or have_tools
                        required: get_option('seccomp'),
                        method: 'pkg-config', static: enable_static)
 endif
+
 libcap_ng = not_found
-if 'CONFIG_LIBCAP_NG' in config_host
-  libcap_ng = declare_dependency(link_args: config_host['LIBCAP_NG_LIBS'].split())
+if not get_option('cap_ng').auto() or have_system or have_tools
+  libcap_ng = cc.find_library('cap-ng', has_headers: ['cap-ng.h'],
+                              required: get_option('cap_ng'),
+                              static: enable_static)
 endif
+if libcap_ng.found() and not cc.links('''
+   #include <cap-ng.h>
+   int main(void)
+   {
+     capng_capability_to_name(CAPNG_EFFECTIVE);
+     return 0;
+   }''', dependencies: libcap_ng)
+  libcap_ng = not_found
+  if get_option('cap_ng').enabled()
+    error('could not link libcap-ng')
+  else
+    warning('could not link libcap-ng, disabling')
+  endif
+endif
+
 if get_option('xkbcommon').auto() and not have_system and not have_tools
   xkbcommon = not_found
 else
@@ -1013,6 +1031,7 @@ if glusterfs.found()
   config_host_data.set('CONFIG_GLUSTERFS_FTRUNCATE_HAS_STAT', glusterfs_ftruncate_has_stat)
   config_host_data.set('CONFIG_GLUSTERFS_IOCB_HAS_STAT', glusterfs_iocb_has_stat)
 endif
+config_host_data.set('CONFIG_LIBCAP_NG', libcap_ng.found())
 config_host_data.set('CONFIG_LIBISCSI', libiscsi.found())
 config_host_data.set('CONFIG_LIBNFS', libnfs.found())
 config_host_data.set('CONFIG_RBD', rbd.found())
@@ -2354,7 +2373,7 @@ summary_info += {'fdatasync':         config_host.has_key('CONFIG_FDATASYNC')}
 summary_info += {'madvise':           config_host.has_key('CONFIG_MADVISE')}
 summary_info += {'posix_madvise':     config_host.has_key('CONFIG_POSIX_MADVISE')}
 summary_info += {'posix_memalign':    config_host.has_key('CONFIG_POSIX_MEMALIGN')}
-summary_info += {'libcap-ng support': config_host.has_key('CONFIG_LIBCAP_NG')}
+summary_info += {'libcap-ng support': libcap_ng.found()}
 summary_info += {'vhost-kernel support': config_host.has_key('CONFIG_VHOST_KERNEL')}
 summary_info += {'vhost-net support': config_host.has_key('CONFIG_VHOST_NET')}
 summary_info += {'vhost-crypto support': config_host.has_key('CONFIG_VHOST_CRYPTO')}

meson_options.txt

@@ -44,6 +44,8 @@ option('brlapi', type : 'feature', value : 'auto',
        description: 'brlapi character device driver')
 option('bzip2', type : 'feature', value : 'auto',
        description: 'bzip2 support for DMG images')
+option('cap_ng', type : 'feature', value : 'auto',
+       description: 'cap_ng support')
 option('cocoa', type : 'feature', value : 'auto',
        description: 'Cocoa user interface (macOS only)')
 option('curl', type : 'feature', value : 'auto',

tools/meson.build

@@ -1,14 +1,14 @@
 have_virtiofsd = (targetos == 'linux' and
     have_tools and
     seccomp.found() and
-    'CONFIG_LIBCAP_NG' in config_host and
+    libcap_ng.found() and
     'CONFIG_VHOST_USER' in config_host)
 
 if get_option('virtiofsd').enabled()
   if not have_virtiofsd
     if targetos != 'linux'
       error('virtiofsd requires Linux')
-    elif not seccomp.found() or 'CONFIG_LIBCAP_NG' not in config_host
+    elif not seccomp.found() or not libcap_ng.found()
       error('virtiofsd requires libcap-ng-devel and seccomp-devel')
     elif not have_tools or 'CONFIG_VHOST_USER' not in config_host
       error('virtiofsd needs tools and vhost-user support')