[coverage] Block coverage with support for IfStatements

src/interpreter/bytecode-generator.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/interpreter/bytecode-generator.h"
 
 #include "src/ast/compile-time-value.h"
 #include "src/ast/scopes.h"
 #include "src/builtins/builtins-constructor.h"
 #include "src/code-stubs.h"
@@ skipping 628 matching lines @@
       info_(info),
       ast_string_constants_(info->isolate()->ast_string_constants()),
       closure_scope_(info->scope()),
       current_scope_(info->scope()),
       globals_builder_(new (zone()) GlobalDeclarationsBuilder(info->zone())),
       global_declarations_(0, info->zone()),
       function_literals_(0, info->zone()),
       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),
       generator_jump_table_(nullptr),
       generator_state_(),
       loop_depth_(0) {
   DCHECK_EQ(closure_scope(), closure_scope()->GetClosureScope());
 }
 
 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);
 }
 
 void BytecodeGenerator::AllocateDeferredConstants(Isolate* isolate) {
   // Build global declaration pair arrays.
   for (GlobalDeclarationsBuilder* globals_builder : global_declarations_) {
     Handle<FixedArray> declarations =
         globals_builder->AllocateDeclarations(info());
     if (declarations.is_null()) return SetStackOverflow();
@@ skipping 379 matching lines @@
 void BytecodeGenerator::VisitExpressionStatement(ExpressionStatement* stmt) {
   builder()->SetStatementPosition(stmt);
   VisitForEffect(stmt->expression());
 }
 
 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 {
     // TODO(oth): If then statement is BreakStatement or
     // ContinueStatement we can reduce number of generated
     // jump/jump_ifs here. See BasicLoops test.
     BytecodeLabel end_label;
     BytecodeLabels then_labels(zone()), else_labels(zone());
     VisitForTest(stmt->condition(), &then_labels, &else_labels,
                  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());
     }
     builder()->Bind(&end_label);
   }
 }
 
 void BytecodeGenerator::VisitSloppyBlockFunctionStatement(
     SloppyBlockFunctionStatement* stmt) {
@@ skipping 2582 matching lines @@
 }
 
 LanguageMode BytecodeGenerator::language_mode() const {
   return current_scope()->language_mode();
 }
 
 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;
 }
 
 Runtime::FunctionId BytecodeGenerator::StoreKeyedToSuperRuntimeId() {
   return is_strict(language_mode()) ? Runtime::kStoreKeyedToSuper_Strict
                                     : Runtime::kStoreKeyedToSuper_Sloppy;
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8