Bug 1204169 - Push SPS pseudo frame entries when GCing; r=terrence

js/src/gc/GCInternals.h

@@ -56,6 +56,7 @@ class MOZ_RAII AutoTraceSession
     void operator=(const AutoTraceSession&) = delete;
 
     JS::HeapState prevState;
+    AutoSPSEntry pseudoFrame;
 };
 
 struct MOZ_RAII AutoPrepareForTracing

js/src/jsgc.cpp

@@ -5580,11 +5580,29 @@ GCRuntime::finishCollection(JS::gcreason::Reason reason)
     }
 }
 
+static const char*
+HeapStateToLabel(JS::HeapState heapState)
+{
+    switch (heapState) {
+      case JS::HeapState::MinorCollecting:
+        return "js::Nursery::collect";
+      case JS::HeapState::MajorCollecting:
+        return "js::GCRuntime::collect";
+      case JS::HeapState::Tracing:
+        return "JS_IterateCompartments";
+      case JS::HeapState::Idle:
+        MOZ_CRASH("Should never have an Idle heap state when pushing GC pseudo frames!");
+    }
+    MOZ_ASSERT_UNREACHABLE("Should have exhausted every JS::HeapState variant!");
+    return nullptr;
+}
+
 /* Start a new heap session. */
 AutoTraceSession::AutoTraceSession(JSRuntime* rt, JS::HeapState heapState)
   : lock(rt),
     runtime(rt),
-    prevState(rt->heapState_)
+    prevState(rt->heapState_),
+    pseudoFrame(rt, HeapStateToLabel(heapState), ProfileEntry::Category::GC)
 {
     MOZ_ASSERT(rt->heapState_ == JS::HeapState::Idle);
     MOZ_ASSERT(heapState != JS::HeapState::Idle);