[ast] Annotate some nodes with number of yields.

src/ast/ast-numbering.cc

Index: src/ast/ast-numbering.cc
diff --git a/src/ast/ast-numbering.cc b/src/ast/ast-numbering.cc
index 1c345c2f4133d52cf805d3e53b3a84634add7ff3..b34da82f8d3788afbb315e6c9a24043130a0274e 100644
--- a/src/ast/ast-numbering.cc
+++ b/src/ast/ast-numbering.cc
@@ -17,6 +17,7 @@ class AstNumberingVisitor final : public AstVisitor {
         isolate_(isolate),
         zone_(zone),
         next_id_(BailoutId::FirstUsable().ToInt()),
+        yield_count_(0),
         properties_(zone),
         slot_cache_(zone),
         dont_optimize_reason_(kNoReason) {
@@ -31,8 +32,6 @@ class AstNumberingVisitor final : public AstVisitor {
   AST_NODE_LIST(DEFINE_VISIT)
 #undef DEFINE_VISIT
 
-  bool Finish(FunctionLiteral* node);
-
   void VisitVariableProxyReference(VariableProxy* node);
   void VisitPropertyReference(Property* node);
   void VisitReference(Expression* expr);
@@ -73,9 +72,21 @@ class AstNumberingVisitor final : public AstVisitor {
 
   BailoutReason dont_optimize_reason() const { return dont_optimize_reason_; }
 
+  int GetAndResetYieldCount() {
+    int old_yield_count = yield_count_;
+    yield_count_ = 0;
+    return old_yield_count;
+  }
+
+  void StoreAndUpdateYieldCount(IterationStatement* node, int old_yield_count) {
+    node->set_yield_count(yield_count_);
+    yield_count_ += old_yield_count;
+  }
+
   Isolate* isolate_;
   Zone* zone_;
   int next_id_;
+  int yield_count_;
   AstProperties properties_;
   // The slot cache allows us to reuse certain feedback vector slots.
   FeedbackVectorSlotCache slot_cache_;
@@ -217,6 +228,7 @@ void AstNumberingVisitor::VisitReturnStatement(ReturnStatement* node) {
 
 
 void AstNumberingVisitor::VisitYield(Yield* node) {
+  yield_count_++;
   IncrementNodeCount();
   DisableOptimization(kYield);
   ReserveFeedbackSlots(node);
@@ -284,8 +296,10 @@ void AstNumberingVisitor::VisitDoWhileStatement(DoWhileStatement* node) {
   IncrementNodeCount();
   DisableSelfOptimization();
   node->set_base_id(ReserveIdRange(DoWhileStatement::num_ids()));
+  int old_yield_count = GetAndResetYieldCount();
   Visit(node->body());
   Visit(node->cond());
+  StoreAndUpdateYieldCount(node, old_yield_count);
 }
 
 
@@ -293,8 +307,10 @@ void AstNumberingVisitor::VisitWhileStatement(WhileStatement* node) {
   IncrementNodeCount();
   DisableSelfOptimization();
   node->set_base_id(ReserveIdRange(WhileStatement::num_ids()));
+  int old_yield_count = GetAndResetYieldCount();
   Visit(node->cond());
   Visit(node->body());
+  StoreAndUpdateYieldCount(node, old_yield_count);
 }
 
 
@@ -377,9 +393,11 @@ void AstNumberingVisitor::VisitForInStatement(ForInStatement* node) {
   IncrementNodeCount();
   DisableSelfOptimization();
   node->set_base_id(ReserveIdRange(ForInStatement::num_ids()));
+  Visit(node->enumerable());  // Not part of loop.

[neis, 2016/04/13 09:54:27]

Here I'm changing the order of visits, for convenience.  I'm assuming this is
fine.

+  int old_yield_count = GetAndResetYieldCount();
   Visit(node->each());
-  Visit(node->enumerable());
   Visit(node->body());
+  StoreAndUpdateYieldCount(node, old_yield_count);
   ReserveFeedbackSlots(node);
 }
 
@@ -388,11 +406,13 @@ void AstNumberingVisitor::VisitForOfStatement(ForOfStatement* node) {
   IncrementNodeCount();
   DisableCrankshaft(kForOfStatement);
   node->set_base_id(ReserveIdRange(ForOfStatement::num_ids()));
-  Visit(node->assign_iterator());
+  Visit(node->assign_iterator());  // Not part of loop.
+  int old_yield_count = GetAndResetYieldCount();
   Visit(node->next_result());
   Visit(node->result_done());
   Visit(node->assign_each());
   Visit(node->body());
+  StoreAndUpdateYieldCount(node, old_yield_count);
   ReserveFeedbackSlots(node);
 }
 
@@ -440,10 +460,12 @@ void AstNumberingVisitor::VisitForStatement(ForStatement* node) {
   IncrementNodeCount();
   DisableSelfOptimization();
   node->set_base_id(ReserveIdRange(ForStatement::num_ids()));
-  if (node->init() != NULL) Visit(node->init());
+  if (node->init() != NULL) Visit(node->init());  // Not part of loop.
+  int old_yield_count = GetAndResetYieldCount();
   if (node->cond() != NULL) Visit(node->cond());
   if (node->next() != NULL) Visit(node->next());
   Visit(node->body());
+  StoreAndUpdateYieldCount(node, old_yield_count);
 }
 
 
@@ -554,13 +576,6 @@ void AstNumberingVisitor::VisitRewritableExpression(
 }
 
 
-bool AstNumberingVisitor::Finish(FunctionLiteral* node) {
-  node->set_ast_properties(&properties_);
-  node->set_dont_optimize_reason(dont_optimize_reason());
-  return !HasStackOverflow();
-}
-
-
 bool AstNumberingVisitor::Renumber(FunctionLiteral* node) {
   Scope* scope = node->scope();
   if (scope->new_target_var()) DisableCrankshaft(kSuperReference);
@@ -577,7 +592,10 @@ bool AstNumberingVisitor::Renumber(FunctionLiteral* node) {
   VisitDeclarations(scope->declarations());
   VisitStatements(node->body());
 
-  return Finish(node);
+  node->set_ast_properties(&properties_);
+  node->set_dont_optimize_reason(dont_optimize_reason());
+  node->set_yield_count(yield_count_);
+  return !HasStackOverflow();
 }