meson: clean up build_by_default

Build all executables by default except for the known-broken ones.

This also allows running qemu-iotests without manually building
socket_scm_helper.

Reported-by: Max Reitz <mreitz@redhat.com>
Tested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

docs/devel/build-system.rst

@@ -193,6 +193,11 @@ compilation as possible. The Meson "sourceset" functionality is used
 to list the files and their dependency on various configuration  
 symbols.
 
+All executables are built by default, except for some `contrib/`
+binaries that are known to fail to build on some platforms (for example
+32-bit or big-endian platforms).  Tests are also built by default,
+though that might change in the future.
+
 Various subsystems that are common to both tools and emulators have
 their own sourceset, for example `block_ss` for the block device subsystem,
 `chardev_ss` for the character device subsystem, etc.  These sourcesets

tests/fp/meson.build

@@ -541,7 +541,6 @@ fpcflags += [
 fptest = executable(
   'fp-test',
   ['fp-test.c', tfdir / 'slowfloat.c', '../../fpu/softfloat.c'],
-  build_by_default: false,
   link_with: [libtestfloat, libsoftfloat],
   dependencies: [qemuutil],
   include_directories: [sfinc, include_directories(tfdir)],
@@ -628,7 +627,6 @@ test('fp-test:mulAdd', fptest,
 fpbench = executable(
   'fp-bench',
   ['fp-bench.c', '../../fpu/softfloat.c'],
-  build_by_default: false,
   link_with: [libtestfloat, libsoftfloat],
   dependencies: [qemuutil],
   include_directories: [sfinc, include_directories(tfdir)],

tests/meson.build

@@ -251,12 +251,11 @@ foreach bench_name, deps: benchs
             suite: ['speed'])
 endforeach
 
-if have_tools and 'CONFIG_VHOST_USER' in config_host
+if have_tools and 'CONFIG_VHOST_USER' in config_host and 'CONFIG_LINUX' in config_host
   executable('vhost-user-bridge',
              sources: files('vhost-user-bridge.c'),
              link_with: [libvhost_user],
-             dependencies: [qemuutil],
-             build_by_default: false)
+             dependencies: [qemuutil])
 endif
 
 if have_system and 'CONFIG_POSIX' in config_host

tests/qemu-iotests/meson.build

 if 'CONFIG_LINUX' in config_host
-    socket_scm_helper = executable('socket_scm_helper', 'socket_scm_helper.c',
-                                    build_by_default: false)
+    socket_scm_helper = executable('socket_scm_helper', 'socket_scm_helper.c')
 else
     socket_scm_helper = []
 endif

trace/meson.build

@@ -70,7 +70,6 @@ foreach d : [
                 output: d[0],
                 input: meson.source_root() / 'trace-events',
                 command: [ tracetool, '--group=root', '--format=@0@'.format(d[1]), '@INPUT@' ],
-                build_by_default: true, # to be removed when added to a target
                 capture: true)
   specific_ss.add(gen)
 endforeach

ui/shader/meson.build

@@ -9,7 +9,6 @@ foreach e : shaders
   genh += custom_target(output,
                 output: output,
                 capture: true,
-                build_by_default: true, # to be removed when added to a target
                 input: files('@0@.@1@'.format(e[0], e[1])),
                 command: [shaderinclude, '@INPUT0@'])
 endforeach