configure: compute derivatives of target name in meson

Several CONFIG_* symbols in config-target.mak are easily computed from just
the target name.  We do not need them in config-target.mak, and can instead
place them in the config_target dictionary only.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -7599,7 +7599,6 @@ upper() {
 
 target_arch_name="$(upper $TARGET_ARCH)"
 echo "TARGET_$target_arch_name=y" >> $config_target_mak
-echo "TARGET_NAME=$target_name" >> $config_target_mak
 echo "TARGET_BASE_ARCH=$TARGET_BASE_ARCH" >> $config_target_mak
 if [ "$TARGET_ABI_DIR" = "" ]; then
   TARGET_ABI_DIR=$TARGET_ARCH
@@ -7617,21 +7616,15 @@ if test "$target_bigendian" = "yes" ; then
   echo "TARGET_WORDS_BIGENDIAN=y" >> $config_target_mak
 fi
 if test "$target_softmmu" = "yes" ; then
-  echo "CONFIG_SOFTMMU=y" >> $config_target_mak
   if test "$mttcg" = "yes" ; then
     echo "TARGET_SUPPORTS_MTTCG=y" >> $config_target_mak
   fi
 fi
 if test "$target_user_only" = "yes" ; then
-  echo "CONFIG_USER_ONLY=y" >> $config_target_mak
-  echo "CONFIG_QEMU_INTERP_PREFIX=\"$interp_prefix1\"" >> $config_target_mak
   symlink "../qemu-$target_name" "$target_dir/qemu-$target_name"
 else
   symlink "../qemu-system-$target_name" "$target_dir/qemu-system-$target_name"
 fi
-if test "$target_linux_user" = "yes" ; then
-  echo "CONFIG_LINUX_USER=y" >> $config_target_mak
-fi
 list=""
 if test ! -z "$gdb_xml_files" ; then
   for x in $gdb_xml_files; do
@@ -7643,9 +7636,6 @@ fi
 if test "$target_user_only" = "yes" && test "$bflt" = "yes"; then
   echo "TARGET_HAS_BFLT=y" >> $config_target_mak
 fi
-if test "$target_bsd_user" = "yes" ; then
-  echo "CONFIG_BSD_USER=y" >> $config_target_mak
-fi
 
 done # for target in $targets
 
@@ -7655,6 +7645,7 @@ fi
 if [ "$capstone" = "git" -o "$capstone" = "internal" ]; then
   subdirs="$subdirs capstone"
 fi
+echo "CONFIG_QEMU_INTERP_PREFIX=$interp_prefix" | sed 's/%M/@0@/' >> $config_host_mak
 echo "SUBDIRS=$subdirs" >> $config_host_mak
 if test -n "$LIBCAPSTONE"; then
   echo "LIBCAPSTONE=$LIBCAPSTONE" >> $config_host_mak

meson.build

@@ -639,12 +639,15 @@ config_host_data.set('QEMU_VERSION_MAJOR', meson.project_version().split('.')[0]
 config_host_data.set('QEMU_VERSION_MINOR', meson.project_version().split('.')[1])
 config_host_data.set('QEMU_VERSION_MICRO', meson.project_version().split('.')[2])
 
+ignored = ['CONFIG_QEMU_INTERP_PREFIX'] # actually per-target
 arrays = ['CONFIG_AUDIO_DRIVERS', 'CONFIG_BDRV_RW_WHITELIST', 'CONFIG_BDRV_RO_WHITELIST']
 strings = ['HOST_DSOSUF', 'CONFIG_IASL', 'bindir', 'prefix', 'qemu_confdir', 'qemu_datadir',
            'qemu_moddir', 'qemu_localstatedir', 'qemu_helperdir', 'qemu_localedir',
            'qemu_icondir', 'qemu_desktopdir', 'qemu_firmwarepath', 'sysconfdir']
 foreach k, v: config_host
-  if arrays.contains(k)
+  if ignored.contains(k)
+    # do nothing
+  elif arrays.contains(k)
     if v != ''
       v = '"' + '", "'.join(v.split()) + '", '
     endif
@@ -721,7 +724,23 @@ kconfig_external_symbols = [
 ignored = ['TARGET_XML_FILES', 'TARGET_ABI_DIR', 'TARGET_DIRS']
 
 foreach target : target_dirs
-  config_target = keyval.load(meson.current_build_dir() / target / 'config-target.mak')
+  config_target = { 'TARGET_NAME': target.split('-')[0] }
+  if target.endswith('linux-user')
+    assert(targetos == 'linux')
+    config_target += { 'CONFIG_LINUX_USER': 'y' }
+  elif target.endswith('bsd-user')
+    assert('CONFIG_BSD' in config_host)
+    config_target += { 'CONFIG_BSD_USER': 'y' }
+  elif target.endswith('softmmu')
+    config_target += { 'CONFIG_SOFTMMU': 'y' }
+  endif
+  if target.endswith('-user')
+    config_target += {
+      'CONFIG_USER_ONLY': 'y',
+      'CONFIG_QEMU_INTERP_PREFIX':
+        config_host['CONFIG_QEMU_INTERP_PREFIX'].format(config_target['TARGET_NAME'])
+    }
+  endif
 
   have_accel = false
   foreach sym: accelerators
@@ -736,6 +755,8 @@ foreach target : target_dirs
   endforeach
   assert(have_accel)
 
+  config_target += keyval.load('default-configs/targets' / target + '.mak')
+
   foreach k, v: disassemblers
     if config_host['ARCH'].startswith(k) or config_target['TARGET_BASE_ARCH'].startswith(k)
       foreach sym: v
@@ -753,7 +774,7 @@ foreach target : target_dirs
       # do nothing
     elif k == 'TARGET_BASE_ARCH'
       config_target_data.set('TARGET_' + v.to_upper(), 1)
-    elif k == 'TARGET_NAME'
+    elif k == 'TARGET_NAME' or k == 'CONFIG_QEMU_INTERP_PREFIX'
       config_target_data.set_quoted(k, v)
     elif v == 'y'
       config_target_data.set(k, 1)