Fix bug where generators got closed prematurely.

test/cctest/test-ast-expression-visitor.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 <stdlib.h>
 
 #include "src/v8.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/ast-expression-visitor.h"
@@ skipping 325 matching lines @@
     }
   }
   CHECK_TYPES_END
 }
 
 
 TEST(VisitThrow) {
   v8::V8::Initialize();
   HandleAndZoneScope handles;
   ZoneVector<ExpressionTypeEntry> types(handles.main_zone());
-  // Check that traversing an empty for statement works.
   const char test_function[] =
       "function foo() {\n"
       "  throw 123;\n"
       "}\n";
   CollectTypes(&handles, test_function, &types);
   CHECK_TYPES_BEGIN {
     CHECK_EXPR(FunctionLiteral, Bounds::Unbounded()) {
       CHECK_EXPR(Throw, Bounds::Unbounded()) {
         CHECK_EXPR(Literal, Bounds::Unbounded());
       }
     }
   }
   CHECK_TYPES_END
 }
 
 
 TEST(VisitYield) {
   v8::V8::Initialize();
   HandleAndZoneScope handles;
   ZoneVector<ExpressionTypeEntry> types(handles.main_zone());
-  // Check that traversing an empty for statement works.
   const char test_function[] =
       "function* foo() {\n"
       "  yield 123;\n"
       "}\n";
   CollectTypes(&handles, test_function, &types);
   CHECK_TYPES_BEGIN {
     CHECK_EXPR(FunctionLiteral, Bounds::Unbounded()) {
-      // Generator function yields generator on entry.
+      // Implicit initial yield
       CHECK_EXPR(Yield, Bounds::Unbounded()) {
         CHECK_VAR(.generator_object, Bounds::Unbounded());
         CHECK_EXPR(Assignment, Bounds::Unbounded()) {
           CHECK_VAR(.generator_object, Bounds::Unbounded());
           CHECK_EXPR(CallRuntime, Bounds::Unbounded());
         }
       }
-      // Then yields undefined.
+      // Explicit yield
       CHECK_EXPR(Yield, Bounds::Unbounded()) {
         CHECK_VAR(.generator_object, Bounds::Unbounded());
         CHECK_EXPR(Literal, Bounds::Unbounded());
       }
-      // Then yields 123.
+      // Implicit final yield
       CHECK_EXPR(Yield, Bounds::Unbounded()) {
         CHECK_VAR(.generator_object, Bounds::Unbounded());
         CHECK_EXPR(Literal, Bounds::Unbounded());
       }
+      // Implicit finally clause
+      CHECK_EXPR(CallRuntime, Bounds::Unbounded()) {
+        CHECK_VAR(.generator_object, Bounds::Unbounded());
+      }
     }
   }
   CHECK_TYPES_END
 }
 
 
 TEST(VisitSkipping) {
   v8::V8::Initialize();
   HandleAndZoneScope handles;
   ZoneVector<ExpressionTypeEntry> types(handles.main_zone());
-  // Check that traversing an empty for statement works.
   const char test_function[] =
       "function foo(x) {\n"
       "  return (x + x) + 1;\n"
       "}\n";
   CollectTypes(&handles, test_function, &types);
   CHECK_TYPES_BEGIN {
     CHECK_EXPR(FunctionLiteral, Bounds::Unbounded()) {
       CHECK_EXPR(BinaryOperation, Bounds::Unbounded()) {
         // Skip x + x
         CHECK_SKIP();
         CHECK_EXPR(Literal, Bounds::Unbounded());
       }
     }
   }
   CHECK_TYPES_END
 }