[coverage] Block coverage with support for IfStatements

src/interpreter/bytecode-generator.h

Index: src/interpreter/bytecode-generator.h
diff --git a/src/interpreter/bytecode-generator.h b/src/interpreter/bytecode-generator.h
index 579365952b9fae9bd4fc51e4c902c0b8bd0c4133..55c6fc1342da0d82ce0c2545880077aacbfb71a4 100644
--- a/src/interpreter/bytecode-generator.h
+++ b/src/interpreter/bytecode-generator.h
@@ -236,6 +236,19 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
   inline LanguageMode language_mode() const;
   int feedback_index(FeedbackSlot slot) const;
 
+  bool is_block_coverage() const;
+  int AllocateBlockCoverageSlot(SourceRange range) {
+    if (!is_block_coverage() || range.IsEmpty()) return -1;
+    const int slot = static_cast<int>(block_coverage_slots_.size());
+    block_coverage_slots_.emplace_back(range);
+    return slot;
+  }
+  void IncBlockCounter(SourceRange range) {
+    if (is_block_coverage() && !range.IsEmpty()) {
+      builder()->IncBlockCounter(AllocateBlockCoverageSlot(range));
+    }
+  }
+
   Zone* zone_;
   BytecodeArrayBuilder* builder_;
   CompilationInfo* info_;
@@ -251,6 +264,10 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
   ZoneVector<std::pair<ObjectLiteral*, size_t>> object_literals_;
   ZoneVector<std::pair<ArrayLiteral*, size_t>> array_literals_;
 
+  // Contains source range information for allocated block coverage counter
+  // slots. Slot i covers range block_coverage_slots_[i].
+  ZoneVector<SourceRange> block_coverage_slots_;
+
   ControlScope* execution_control_;
   ContextScope* execution_context_;
   ExpressionResultScope* execution_result_;