[coverage] Block coverage with support for IfStatements

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 549137a08e710dbfa38f7d8e98647eadb45a11d5..0d756c9a681fb7856c9d162d58d6097508acc701 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -13657,6 +13657,7 @@ void SharedFunctionInfo::InitFromFunctionLiteral(
   shared_info->set_needs_home_object(lit->scope()->NeedsHomeObject());
   shared_info->set_asm_function(lit->scope()->asm_function());
   shared_info->set_function_literal_id(lit->function_literal_id());
+  shared_info->set_coverage_info(Smi::kZero);  // Set later on bytecode-gen.
 
   // For lazy parsed functions, the following flags will be inaccurate since we
   // don't have the information yet. They're set later in
@@ -19284,6 +19285,43 @@ int BreakPointInfo::GetBreakPointCount() {
   return FixedArray::cast(break_point_objects())->length();
 }
 
+int CoverageInfo::SlotCount() const {
+  DCHECK_EQ(kFirstSlotIndex, length() % kSlotIndexCount);
+  return (length() - kFirstSlotIndex) / kSlotIndexCount;
+}
+
+int CoverageInfo::FromSourcePosition(int slot_index) const {
+  DCHECK_LT(slot_index, SlotCount());
+  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
+  return Smi::ToInt(get(slot_start + kSlotFromSourcePositionIndex));
+}
+
+int CoverageInfo::ToSourcePosition(int slot_index) const {
+  DCHECK_LT(slot_index, SlotCount());
+  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
+  return Smi::ToInt(get(slot_start + kSlotToSourcePositionIndex));
+}
+
+int CoverageInfo::BlockCount(int slot_index) const {
+  DCHECK_LT(slot_index, SlotCount());
+  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
+  return Smi::ToInt(get(slot_start + kSlotBlockCountIndex));
+}
+
+void CoverageInfo::InitializeSlot(int slot_index, int from_pos, int to_pos) {
+  DCHECK_LT(slot_index, SlotCount());
+  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
+  set(slot_start + kSlotFromSourcePositionIndex, Smi::FromInt(from_pos));
+  set(slot_start + kSlotToSourcePositionIndex, Smi::FromInt(to_pos));
+  set(slot_start + kSlotBlockCountIndex, Smi::kZero);
+}
+
+void CoverageInfo::IncrementBlockCount(int slot_index) {
+  DCHECK_LT(slot_index, SlotCount());
+  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
+  const int old_count = BlockCount(slot_index);
+  set(slot_start + kSlotBlockCountIndex, Smi::FromInt(old_count + 1));
+}
 
 // static
 MaybeHandle<JSDate> JSDate::New(Handle<JSFunction> constructor,