meson: Fix build with --disable-guest-agent-msi

The QGA MSI target requires several macros which are only available
without --disable-guest-agent-msi.

Don't define that target if configure was called with --disable-guest-agent-msi.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Message-Id: <20201117201834.408892-1-sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

qga/meson.build

@@ -61,23 +61,25 @@ if targetos == 'windows'
     if 'CONFIG_QGA_VSS' in config_host and 'QEMU_GA_MSI_WITH_VSS' in config_host
       deps += qga_vss
     endif
-    qga_msi = custom_target('QGA MSI',
-                            input: files('installer/qemu-ga.wxs'),
-                            output: 'qemu-ga-@0@.msi'.format(config_host['ARCH']),
-                            depends: deps,
-                            command: [
-                              find_program('env'),
-                              'QEMU_GA_VERSION=' + config_host['QEMU_GA_VERSION'],
-                              'QEMU_GA_MANUFACTURER=' + config_host['QEMU_GA_MANUFACTURER'],
-                              'QEMU_GA_DISTRO=' + config_host['QEMU_GA_DISTRO'],
-                              'BUILD_DIR=' + meson.build_root(),
-                              wixl, '-o', '@OUTPUT0@', '@INPUT0@',
-                              config_host['QEMU_GA_MSI_ARCH'].split(),
-                              config_host['QEMU_GA_MSI_WITH_VSS'].split(),
-                              config_host['QEMU_GA_MSI_MINGW_DLL_PATH'].split(),
-                            ])
-    all_qga += [qga_msi]
-    alias_target('msi', qga_msi)
+    if 'CONFIG_QGA_MSI' in config_host
+      qga_msi = custom_target('QGA MSI',
+                              input: files('installer/qemu-ga.wxs'),
+                              output: 'qemu-ga-@0@.msi'.format(config_host['ARCH']),
+                              depends: deps,
+                              command: [
+                                find_program('env'),
+                                'QEMU_GA_VERSION=' + config_host['QEMU_GA_VERSION'],
+                                'QEMU_GA_MANUFACTURER=' + config_host['QEMU_GA_MANUFACTURER'],
+                                'QEMU_GA_DISTRO=' + config_host['QEMU_GA_DISTRO'],
+                                'BUILD_DIR=' + meson.build_root(),
+                                wixl, '-o', '@OUTPUT0@', '@INPUT0@',
+                                config_host['QEMU_GA_MSI_ARCH'].split(),
+                                config_host['QEMU_GA_MSI_WITH_VSS'].split(),
+                                config_host['QEMU_GA_MSI_MINGW_DLL_PATH'].split(),
+                              ])
+      all_qga += [qga_msi]
+      alias_target('msi', qga_msi)
+    endif
   endif
 else
   install_subdir('run', install_dir: get_option('localstatedir'))