[coverage] Block coverage with support for IfStatements

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index 1eb4fdc147ab735034968799b0b32029ec5e89cf..eb43915761cb94f569e06165620b48df9e9c97aa 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -646,6 +646,7 @@ BytecodeGenerator::BytecodeGenerator(CompilationInfo* info)
       native_function_literals_(0, info->zone()),
       object_literals_(0, info->zone()),
       array_literals_(0, info->zone()),
+      block_coverage_slots_(0, info->zone()),
       execution_control_(nullptr),
       execution_context_(nullptr),
       execution_result_(nullptr),
@@ -657,6 +658,13 @@ BytecodeGenerator::BytecodeGenerator(CompilationInfo* info)
 
 Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(Isolate* isolate) {
   AllocateDeferredConstants(isolate);
+
+  if (is_block_coverage()) {
+    Handle<CoverageInfo> coverage_info =
+        isolate->factory()->NewCoverageInfo(block_coverage_slots_);
+    info()->shared_info()->set_coverage_info(*coverage_info);

[rmcilroy, 2017/05/18 14:17:59]

We don't set things in the shared_info in the bytecode generator and I would
rather we didn't do this here. Can we instead set something on the CompileInfo
(maybe even just the slot count for allocation at a later point).

[jgruber, 2017/05/22 09:43:32]

I changed this to store the CoverageInfo on CompilationInfo, and move it to the
SFI in FinalizeUnoptimizedCompilationJob.

(The mapping between coverage slot and source range needs to happen before
bytecode generation so we can't pass only the slot count.)

+  }
+
   if (HasStackOverflow()) return Handle<BytecodeArray>();
   return builder()->ToBytecodeArray(isolate);
 }
@@ -1056,12 +1064,15 @@ void BytecodeGenerator::VisitEmptyStatement(EmptyStatement* stmt) {
 
 void BytecodeGenerator::VisitIfStatement(IfStatement* stmt) {
   builder()->SetStatementPosition(stmt);
+
   if (stmt->condition()->ToBooleanIsTrue()) {
     // Generate then block unconditionally as always true.
+    IncBlockCounter(stmt->then_range());
     Visit(stmt->then_statement());
   } else if (stmt->condition()->ToBooleanIsFalse()) {
     // Generate else block unconditionally if it exists.
     if (stmt->HasElseStatement()) {
+      IncBlockCounter(stmt->else_range());
       Visit(stmt->else_statement());
     }
   } else {
@@ -1074,11 +1085,13 @@ void BytecodeGenerator::VisitIfStatement(IfStatement* stmt) {
                  TestFallthrough::kThen);
 
     then_labels.Bind(builder());
+    IncBlockCounter(stmt->then_range());
     Visit(stmt->then_statement());
 
     if (stmt->HasElseStatement()) {
       builder()->Jump(&end_label);
       else_labels.Bind(builder());
+      IncBlockCounter(stmt->else_range());
       Visit(stmt->else_statement());
     } else {
       else_labels.Bind(builder());
@@ -3681,6 +3694,11 @@ int BytecodeGenerator::feedback_index(FeedbackSlot slot) const {
   return FeedbackVector::GetIndex(slot);
 }
 
+bool BytecodeGenerator::is_block_coverage() const {
+  return FLAG_block_coverage &&
+         info()->parse_info()->script()->IsUserJavaScript();
+}
+
 Runtime::FunctionId BytecodeGenerator::StoreToSuperRuntimeId() {
   return is_strict(language_mode()) ? Runtime::kStoreToSuper_Strict
                                     : Runtime::kStoreToSuper_Sloppy;