Add foundation tracing and platform build wrapper

tests/CMakeLists.txt

@@ -26,6 +26,16 @@ add_test(NAME pp_foundation_parse_tests COMMAND pp_foundation_parse_tests)
 set_tests_properties(pp_foundation_parse_tests PROPERTIES
     LABELS "foundation;desktop-fast")
 
+add_executable(pp_foundation_trace_tests
+    foundation/trace_tests.cpp)
+target_link_libraries(pp_foundation_trace_tests PRIVATE
+    pp_foundation
+    pp_test_harness)
+
+add_test(NAME pp_foundation_trace_tests COMMAND pp_foundation_trace_tests)
+set_tests_properties(pp_foundation_trace_tests PROPERTIES
+    LABELS "foundation;desktop-fast")
+
 if(TARGET pano_cli)
     add_test(NAME pano_cli_create_document_smoke
         COMMAND pano_cli create-document --width 64 --height 32 --layers 2)

tests/foundation/trace_tests.cpp

@@ -0,0 +1,109 @@
+#include "foundation/trace.h"
+#include "test_harness.h"
+
+using pp::foundation::StatusCode;
+using pp::foundation::TraceRecorder;
+using pp::foundation::TraceSpanDesc;
+
+namespace {
+
+void records_completed_spans_with_context(pp::tests::Harness& h)
+{
+    TraceRecorder recorder;
+
+    const auto id = recorder.begin_span(
+        TraceSpanDesc {
+            .component = "paint",
+            .name = "stroke_commit",
+            .thread_id = 7,
+            .frame_id = 11,
+            .stroke_id = 13,
+        },
+        100);
+
+    PP_EXPECT(h, id.ok());
+    PP_EXPECT(h, recorder.active_span_count() == 1U);
+    PP_EXPECT(h, recorder.end_span(id.value(), 145).ok());
+    PP_EXPECT(h, recorder.active_span_count() == 0U);
+    PP_EXPECT(h, recorder.events().size() == 1U);
+
+    const auto& event = recorder.events()[0];
+    PP_EXPECT(h, event.component == "paint");
+    PP_EXPECT(h, event.name == "stroke_commit");
+    PP_EXPECT(h, event.thread_id == 7U);
+    PP_EXPECT(h, event.frame_id == 11U);
+    PP_EXPECT(h, event.stroke_id == 13U);
+    PP_EXPECT(h, event.start_us == 100U);
+    PP_EXPECT(h, event.duration_us == 45U);
+}
+
+void rejects_invalid_span_descriptions(pp::tests::Harness& h)
+{
+    TraceRecorder recorder;
+
+    const auto no_component = recorder.begin_span(
+        TraceSpanDesc { .component = "", .name = "load" },
+        1);
+    const auto no_name = recorder.begin_span(
+        TraceSpanDesc { .component = "assets", .name = "" },
+        1);
+
+    PP_EXPECT(h, !no_component.ok());
+    PP_EXPECT(h, no_component.status().code == StatusCode::invalid_argument);
+    PP_EXPECT(h, !no_name.ok());
+    PP_EXPECT(h, no_name.status().code == StatusCode::invalid_argument);
+    PP_EXPECT(h, recorder.events().empty());
+}
+
+void rejects_bad_end_calls_without_recording_events(pp::tests::Harness& h)
+{
+    TraceRecorder recorder;
+    const auto id = recorder.begin_span(
+        TraceSpanDesc { .component = "renderer", .name = "readback" },
+        50);
+
+    PP_EXPECT(h, id.ok());
+
+    const auto backwards = recorder.end_span(id.value(), 49);
+    PP_EXPECT(h, !backwards.ok());
+    PP_EXPECT(h, backwards.code == StatusCode::invalid_argument);
+    PP_EXPECT(h, recorder.active_span_count() == 1U);
+    PP_EXPECT(h, recorder.events().empty());
+
+    PP_EXPECT(h, recorder.end_span(id.value(), 51).ok());
+    const auto duplicate = recorder.end_span(id.value(), 52);
+    PP_EXPECT(h, !duplicate.ok());
+    PP_EXPECT(h, duplicate.code == StatusCode::out_of_range);
+    PP_EXPECT(h, recorder.events().size() == 1U);
+}
+
+void clear_resets_events_and_span_ids(pp::tests::Harness& h)
+{
+    TraceRecorder recorder;
+    const auto first = recorder.begin_span(
+        TraceSpanDesc { .component = "ui", .name = "layout" },
+        10);
+    PP_EXPECT(h, first.ok());
+    PP_EXPECT(h, recorder.end_span(first.value(), 20).ok());
+    recorder.clear();
+
+    const auto second = recorder.begin_span(
+        TraceSpanDesc { .component = "ui", .name = "layout" },
+        30);
+    PP_EXPECT(h, second.ok());
+    PP_EXPECT(h, second.value() == first.value());
+    PP_EXPECT(h, recorder.events().empty());
+    PP_EXPECT(h, recorder.active_span_count() == 1U);
+}
+
+}
+
+int main()
+{
+    pp::tests::Harness harness;
+    harness.run("records_completed_spans_with_context", records_completed_spans_with_context);
+    harness.run("rejects_invalid_span_descriptions", rejects_invalid_span_descriptions);
+    harness.run("rejects_bad_end_calls_without_recording_events", rejects_bad_end_calls_without_recording_events);
+    harness.run("clear_resets_events_and_span_ids", clear_resets_events_and_span_ids);
+    return harness.finish();
+}