qapi: generate trace events by default

We don't generate trace events for tests/ and qga/ because that it is
not simple and not necessary. We have corresponding comments in both
tests/meson.build and qga/meson.build.

Still to not miss possible future qapi code generation call, and not to
forget to enable trace events generation, let's enable it by default.
So, turn option --gen-trace into opposite --no-trace-events and use new
option only in tests/ and qga/ where we already have good comments why
we don't generate trace events code.

Note that this commit enables trace-events generation for qapi-gen.py
call from tests/qapi-schema/meson.build and storage-daemon/meson.build.
Still, both are kind of noop: tests/qapi-schema/ doesn't seem to
generate any QMP command code and no .trace-events files anyway,
storage-daemon/ uses common QMP command implementations and just
generate empty .trace-events

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220126161130.3240892-8-vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/meson.build

@@ -127,7 +127,7 @@ endforeach
 qapi_files = custom_target('shared QAPI source files',
   output: qapi_util_outputs + qapi_specific_outputs + qapi_nonmodule_outputs,
   input: [ files('qapi-schema.json') ],
-  command: [ qapi_gen, '-o', 'qapi', '-b', '@INPUT0@', '--gen-trace' ],
+  command: [ qapi_gen, '-o', 'qapi', '-b', '@INPUT0@' ],
   depend_files: [ qapi_inputs, qapi_gen_depends ])
 
 # Now go through all the outputs and add them to the right sourceset.

qga/meson.build

@@ -25,7 +25,8 @@ qga_qapi_outputs = [
 qga_qapi_files = custom_target('QGA QAPI files',
                                output: qga_qapi_outputs,
                                input: 'qapi-schema.json',
-                               command: [ qapi_gen, '-o', 'qga', '-p', 'qga-', '@INPUT0@' ],
+                               command: [ qapi_gen, '-o', 'qga', '-p', 'qga-', '@INPUT0@',
+                                          '--suppress-tracing' ],
                                depend_files: qapi_gen_depends)
 
 qga_ss = ss.source_set()

scripts/qapi/main.py

@@ -76,10 +76,10 @@ def main() -> int:
                         dest='unmask',
                         help="expose non-ABI names in introspection")
 
-    # Option --gen-trace exists so we can avoid solving build system
+    # Option --suppress-tracing exists so we can avoid solving build system
     # problems.  TODO Drop it when we no longer need it.
-    parser.add_argument('--gen-trace', action='store_true',
-                        help="add trace events to qmp marshals")
+    parser.add_argument('--suppress-tracing', action='store_true',
+                        help="suppress adding trace events to qmp marshals")
 
     parser.add_argument('schema', action='store')
     args = parser.parse_args()
@@ -96,7 +96,7 @@ def main() -> int:
                  prefix=args.prefix,
                  unmask=args.unmask,
                  builtins=args.builtins,
-                 gen_tracing=args.gen_trace)
+                 gen_tracing=not args.suppress_tracing)
     except QAPIError as err:
         print(f"{sys.argv[0]}: {str(err)}", file=sys.stderr)
         return 1

tests/meson.build

@@ -44,7 +44,8 @@ test_qapi_files = custom_target('Test QAPI files',
                                              'qapi-schema/include/sub-module.json',
                                              'qapi-schema/sub-sub-module.json'),
                                 command: [ qapi_gen, '-o', meson.current_build_dir(),
-                                           '-b', '-p', 'test-', '@INPUT0@' ],
+                                           '-b', '-p', 'test-', '@INPUT0@',
+                                           '--suppress-tracing' ],
                                 depend_files: qapi_gen_depends)
 
 # meson doesn't like generated output in other directories