Disable allocation folding when allocations tracking is on

BUG=chromium:277984
R=hpayer@chromium.org, loislo@chromium.org, mvstanton@chromium.org, yurys@chromium.org

Review URL: https://codereview.chromium.org/32583002

Patch from Alexandra Mikhaylova <amikhaylova@google.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17337 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.cc

@@ -3308,7 +3308,10 @@ void HAllocate::HandleSideEffectDominator(GVNFlag side_effect,
                                           HValue* dominator) {
   ASSERT(side_effect == kChangesNewSpacePromotion);
   Zone* zone = block()->zone();
-  if (!FLAG_use_allocation_folding) return;
+  if (!FLAG_use_allocation_folding ||
+      isolate()->heap_profiler()->is_tracking_allocations()) {
+    return;
+  }
 
   // Try to fold allocations together with their dominating allocations.
   if (!dominator->IsAllocate()) {

src/hydrogen-instructions.h

@@ -5300,7 +5300,7 @@ class HAllocate V8_FINAL : public HTemplateInstruction<2> {
                         PretenureFlag pretenure_flag,
                         InstanceType instance_type) {
     return new(zone) HAllocate(context, size, type, pretenure_flag,
-        instance_type);
+        instance_type, zone);
   }
 
   // Maximum instance size for which allocations will be inlined.
@@ -5373,7 +5373,8 @@ class HAllocate V8_FINAL : public HTemplateInstruction<2> {
             HValue* size,
             HType type,
             PretenureFlag pretenure_flag,
-            InstanceType instance_type)
+            InstanceType instance_type,
+            Zone* zone)
       : HTemplateInstruction<2>(type),
         dominating_allocate_(NULL),
         filler_free_space_size_(NULL),
@@ -5396,7 +5397,8 @@ class HAllocate V8_FINAL : public HTemplateInstruction<2> {
     // other, i.e., have a pointer to each other. A GC in between these
     // allocations may leave such objects behind in a not completely initialized
     // state.
-    if (!FLAG_use_gvn || !FLAG_use_allocation_folding) {
+    if (!FLAG_use_gvn || !FLAG_use_allocation_folding ||
+        zone->isolate()->heap_profiler()->is_tracking_allocations()) {
       flags_ = static_cast<HAllocate::Flags>(flags_ | PREFILL_WITH_FILLER);
     }
     clear_next_map_word_ = pretenure_flag == NOT_TENURED &&

test/cctest/test-heap-profiler.cc

@@ -2072,3 +2072,23 @@ TEST(HeapObjectsTracker) {
     "    a.shift();\n"
     "findUntrackedObjects();\n");
 }
+
+
+// If we don't disable allocation folding when allocations tracking is on, we
+// may have untracked allocations.
+TEST(DisableAllocationFolding) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  HeapObjectsTracker tracker;
+  CompileRun(
+    "function literal() {"
+    "    return [1];"
+    "}"
+    "function modify_literal(literal, v) {"
+    "    literal[0] = v;"
+    "    return literal;"
+    "}"
+    "obj = modify_literal(literal(), 1);"
+    "obj = modify_literal(literal(), 1.5);"
+    "obj = modify_literal(literal(), 1);");
+}