[async-functions] support await expressions in finally statements

src/ast/ast.h

Index: src/ast/ast.h
diff --git a/src/ast/ast.h b/src/ast/ast.h
index e5c7646ef3a342794ad5db1ded50b13ecd425e73..a17f50a328d8b28d12e2bdde0d5025759aa0478f 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -102,6 +102,7 @@ namespace internal {
   V(SuperCallReference)         \
   V(CaseClause)                 \
   V(EmptyParentheses)           \
+  V(InternalVariable)           \
   V(GetIterator)                \
   V(DoExpression)               \
   V(RewritableExpression)
@@ -2514,7 +2515,8 @@ class Yield final : public Expression {
  public:
   enum OnException { kOnExceptionThrow, kOnExceptionRethrow };
 
-  Expression* generator_object() const { return generator_object_; }
+  enum YieldType { kNormal, kAwait };
+
   Expression* expression() const { return expression_; }
   OnException on_exception() const {
     return OnExceptionField::decode(bit_field_);
@@ -2523,29 +2525,28 @@ class Yield final : public Expression {
     return on_exception() == kOnExceptionRethrow;
   }
   int yield_id() const { return yield_id_; }
+  YieldType yield_type() const { return YieldTypeField::decode(bit_field_); }
 
-  void set_generator_object(Expression* e) { generator_object_ = e; }
   void set_expression(Expression* e) { expression_ = e; }
   void set_yield_id(int yield_id) { yield_id_ = yield_id; }
 
  private:
   friend class AstNodeFactory;
 
-  Yield(Expression* generator_object, Expression* expression, int pos,
-        OnException on_exception)
-      : Expression(pos, kYield),
-        yield_id_(-1),
-        generator_object_(generator_object),
-        expression_(expression) {
-    bit_field_ |= OnExceptionField::encode(on_exception);
+  Yield(Expression* expression, int pos, OnException on_exception,
+        YieldType yield_type)
+      : Expression(pos, kYield), yield_id_(-1), expression_(expression) {
+    bit_field_ |= OnExceptionField::encode(on_exception) |
+                  YieldTypeField::encode(yield_type);
   }
 
   int yield_id_;
-  Expression* generator_object_;
   Expression* expression_;
 
   class OnExceptionField
       : public BitField<OnException, Expression::kNextBitFieldIndex, 1> {};
+  class YieldTypeField
+      : public BitField<YieldType, OnExceptionField::kNext, 1> {};
 };
 
 
@@ -2583,6 +2584,12 @@ class FunctionLiteral final : public Expression {
   const AstString* raw_name() const { return raw_name_; }
   void set_raw_name(const AstString* name) { raw_name_ = name; }
   DeclarationScope* scope() const { return scope_; }
+
+  // AST desugaring of initialization of non-simple parameters. If non-null,
+  // forces Ignition/TF pipeline.
+  Block* parameter_init_block() const { return parameter_init_block_; }
+  void set_parameter_init_block(Block* block) { parameter_init_block_ = block; }
+
   ZoneList<Statement*>* body() const { return body_; }
   void set_function_token_position(int pos) { function_token_position_ = pos; }
   int function_token_position() const { return function_token_position_; }
@@ -2732,6 +2739,7 @@ class FunctionLiteral final : public Expression {
         has_braces_(has_braces),
         raw_name_(name),
         scope_(scope),
+        parameter_init_block_(nullptr),
         body_(body),
         raw_inferred_name_(ast_value_factory->empty_string()),
         ast_properties_(zone),
@@ -2765,6 +2773,7 @@ class FunctionLiteral final : public Expression {
 
   const AstString* raw_name_;
   DeclarationScope* scope_;
+  Block* parameter_init_block_;
   ZoneList<Statement*>* body_;
   const AstString* raw_inferred_name_;
   Handle<String> inferred_name_;
@@ -2956,6 +2965,23 @@ class EmptyParentheses final : public Expression {
   explicit EmptyParentheses(int pos) : Expression(pos, kEmptyParentheses) {}
 };
 
+class InternalVariable final : public Expression {
+ public:
+  enum Type { kGeneratorObject };
+
+  Type type() const { return type_; }
+
+  const char* name() const;
+
+ private:
+  friend class AstNodeFactory;
+
+  explicit InternalVariable(Type type)
+      : Expression(kNoSourcePosition, kInternalVariable), type_(type) {}
+
+  Type type_;
+};
+
 // Represents the spec operation `GetIterator()`
 // (defined at https://tc39.github.io/ecma262/#sec-getiterator). Ignition
 // desugars this into a LoadIC / JSLoadNamed, CallIC, and a type-check to
@@ -3475,10 +3501,10 @@ class AstNodeFactory final BASE_EMBEDDED {
     return assign;
   }
 
-  Yield* NewYield(Expression* generator_object, Expression* expression, int pos,
-                  Yield::OnException on_exception) {
+  Yield* NewYield(Expression* expression, int pos,
+                  Yield::OnException on_exception, Yield::YieldType type) {
     if (!expression) expression = NewUndefinedLiteral(pos);
-    return new (zone_) Yield(generator_object, expression, pos, on_exception);
+    return new (zone_) Yield(expression, pos, on_exception, type);
   }
 
   Throw* NewThrow(Expression* exception, int pos) {
@@ -3567,6 +3593,10 @@ class AstNodeFactory final BASE_EMBEDDED {
     return new (zone_) EmptyParentheses(pos);
   }
 
+  InternalVariable* NewInternalVariable(InternalVariable::Type type) {
+    return new (zone_) InternalVariable(type);
+  }
+
   GetIterator* NewGetIterator(Expression* iterable, int pos) {
     return new (zone_) GetIterator(iterable, pos);
   }