[PATCH v5 6/7] meson: document, why we don't generate trace events for tests/ and qga/

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Making trace generation work for tests/ and qga/ would involve some
Meson hackery to ensure we generate the trace-events files before
trace-tool uses them. Since we don't actually support tracing there
anyway, we bypass that problem.

Let's add corresponding comments.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 qga/meson.build   | 8 ++++++++
 tests/meson.build | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/qga/meson.build b/qga/meson.build
index cfb1fbc085..79fcf91751 100644
--- a/qga/meson.build
+++ b/qga/meson.build
@@ -15,6 +15,14 @@ qga_qapi_outputs = [
   'qga-qapi-visit.h',
 ]
 
+# We don't generate trace-events, just because it's not simple. For do it,
+# we also should add .trace-events file into qga_qapi_outputs, and than
+# add corresponding element of qga_qapi_files into qapi_trace_events
+# global list, which is processed than in trace/meson.build.
+# This means, that we'll have to move subdir('qga') above subdir('trace')
+# in root meson.build. But that in turn will break the dependency of
+# qga on qemuutil (which depends on trace_ss).
+# So, resolving these dependencies and drop --no-trace-events is a TODO.
 qga_qapi_files = custom_target('QGA QAPI files',
                                output: qga_qapi_outputs,
                                input: 'qapi-schema.json',
diff --git a/tests/meson.build b/tests/meson.build
index 3f3882748a..21857d8b01 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -31,6 +31,14 @@ test_qapi_outputs = [
   'test-qapi-visit.h',
 ]
 
+# We don't generate trace-events, just because it's not simple. For do it,
+# we also should add .trace-events file into test_qapi_outputs, and than
+# add corresponding element of test_qapi_files into qapi_trace_events
+# global list, which is processed than in trace/meson.build.
+# This means, that we'll have to move subdir('tests') above subdir('trace')
+# in root meson.build. But that in turn will break the dependency of
+# tests on qemuutil (which depends on trace_ss).
+# So, resolving these dependencies and drop --no-trace-events is a TODO.
 test_qapi_files = custom_target('Test QAPI files',
                                 output: test_qapi_outputs,
                                 input: files('qapi-schema/qapi-schema-test.json',
-- 
2.31.1