Introduce first marker

Summary: @public Adds a marker section for a complete layout pass

Reviewed By: SidharthGuglani

Differential Revision: D13819447

fbshipit-source-id: 21a80f0fe3d325d804a968508761d115c50d3dc1

tests/InstrumentationTest.cpp

@@ -85,6 +85,16 @@ TEST_F(MarkerTest, marker_end_works) {
       << "pointer returned by `startMarker` was not passed to `endMarker`";
 }
 
+TEST_F(MarkerTest, layout_marker) {
+  auto config = makeConfig();
+  auto root = makeNode(config);
+
+  YGNodeCalculateLayout(root.get(), YGUndefined, YGUndefined, YGDirectionLTR);
+
+  ASSERT_EQ(markerCookie.start.marker, YGMarkerLayout);
+  ASSERT_EQ(markerCookie.start.node, root.get());
+}
+
 void* MarkerTest::startMarker(
     YGMarker marker,
     YGNodeRef node,

yoga/Yoga.cpp

@@ -12,6 +12,7 @@
 #include "YGNode.h"
 #include "YGNodePrint.h"
 #include "Yoga-internal.h"
+#include "instrumentation.h"
 #ifdef _MSC_VER
 #include <float.h>
 
@@ -4004,6 +4005,8 @@ void YGNodeCalculateLayout(
     const float ownerWidth,
     const float ownerHeight,
     const YGDirection ownerDirection) {
+  marker::MarkerSection<YGMarkerLayout> marker{node};
+
   // Increment the generation count. This will force the recursive routine to
   // visit all dirty nodes at least once. Subsequent visits will be skipped if
   // the input parameters don't change.
@@ -4118,8 +4121,9 @@ void YGNodeCalculateLayout(
           0.0f);
 
       // Set whether the two layouts are different or not.
-      node->setLayoutDoesLegacyFlagAffectsLayout(
+      auto neededLegacyStretchBehaviour =
-          !originalNode->isLayoutTreeEqualToNode(*node));
+          !originalNode->isLayoutTreeEqualToNode(*node);
+      node->setLayoutDoesLegacyFlagAffectsLayout(neededLegacyStretchBehaviour);
 
       if (originalNode->getConfig()->printTree) {
         YGNodePrint(