[parser] Remove broken/half-implemented do-expressions

The current implementation isn't very helpful anyway if we ever really want
this.

Change-Id: Iad4132734980937aee462a1613d47887383585a0
Reviewed-on: https://chromium-review.googlesource.com/c/1328928Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57388}

src/ast/scopes.cc

@@ -150,23 +150,6 @@ Scope::Scope(Zone* zone, Scope* outer_scope, ScopeType scope_type)
   outer_scope_->AddInnerScope(this);
 }
 
-Scope::Snapshot::Snapshot(Scope* scope)
-    : outer_scope_and_calls_eval_(scope, scope->scope_calls_eval_),
-      top_inner_scope_(scope->inner_scope_),
-      top_unresolved_(scope->unresolved_list_.first()),
-      top_local_(scope->GetClosureScope()->locals_.end()),
-      top_decl_(scope->GetClosureScope()->decls_.end()) {
-  // Reset in order to record eval calls during this Snapshot's lifetime.
-  outer_scope_and_calls_eval_.GetPointer()->scope_calls_eval_ = false;
-}
-
-Scope::Snapshot::~Snapshot() {
-  // Restore previous calls_eval bit if needed.
-  if (outer_scope_and_calls_eval_.GetPayload()) {
-    outer_scope_and_calls_eval_->scope_calls_eval_ = true;
-  }
-}
-
 DeclarationScope::DeclarationScope(Zone* zone,
                                    AstValueFactory* ast_value_factory)
     : Scope(zone), function_kind_(kNormalFunction), params_(4, zone) {
@@ -897,27 +880,6 @@ void Scope::Snapshot::Reparent(DeclarationScope* new_parent) const {
     outer_scope_->unresolved_list_.ReinitializeHead(top_unresolved_);
   }
 
-  // TODO(verwaest): This currently only moves do-expression declared variables
-  // in default arguments that weren't already previously declared with the same
-  // name in the closure-scope. See
-  // test/mjsunit/harmony/default-parameter-do-expression.js.
-  DeclarationScope* outer_closure = outer_scope_->GetClosureScope();
-
-  new_parent->locals_.MoveTail(outer_closure->locals(), top_local_);
-  for (Variable* local : new_parent->locals_) {
-    DCHECK(local->mode() == VariableMode::kTemporary ||
-           local->mode() == VariableMode::kVar);
-    DCHECK_EQ(local->scope(), local->scope()->GetClosureScope());
-    DCHECK_NE(local->scope(), new_parent);
-    local->set_scope(new_parent);
-    if (local->mode() == VariableMode::kVar) {
-      outer_closure->variables_.Remove(local);
-      new_parent->variables_.Add(new_parent->zone(), local);
-    }
-  }
-  outer_closure->locals_.Rewind(top_local_);
-  outer_closure->decls_.Rewind(top_decl_);
-
   // Move eval calls since Snapshot's creation into new_parent.
   if (outer_scope_->scope_calls_eval_) {
     new_parent->scope_calls_eval_ = true;

src/ast/scopes.h

@@ -122,8 +122,19 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
 
   class Snapshot final {
    public:
-    explicit Snapshot(Scope* scope);
-    ~Snapshot();
+    explicit Snapshot(Scope* scope)
+        : outer_scope_and_calls_eval_(scope, scope->scope_calls_eval_),
+          top_inner_scope_(scope->inner_scope_),
+          top_unresolved_(scope->unresolved_list_.first()) {
+      // Reset in order to record eval calls during this Snapshot's lifetime.
+      outer_scope_and_calls_eval_.GetPointer()->scope_calls_eval_ = false;
+    }
+    ~Snapshot() {
+      // Restore previous calls_eval bit if needed.
+      if (outer_scope_and_calls_eval_.GetPayload()) {
+        outer_scope_and_calls_eval_->scope_calls_eval_ = true;
+      }
+    }
 
     void Reparent(DeclarationScope* new_parent) const;
 
@@ -131,8 +142,6 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
     PointerWithPayload<Scope, bool, 1> outer_scope_and_calls_eval_;
     Scope* top_inner_scope_;
     VariableProxy* top_unresolved_;
-    base::ThreadedList<Variable>::Iterator top_local_;
-    base::ThreadedList<Declaration>::Iterator top_decl_;
   };
 
   enum class DeserializationMode { kIncludingVariables, kScopesOnly };

src/bootstrapper.cc

@@ -4385,7 +4385,6 @@ void Bootstrapper::ExportFromRuntime(Isolate* isolate,
 #define EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(id) \
   void Genesis::InitializeGlobal_##id() {}
 
-EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_do_expressions)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_namespace_exports)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_public_fields)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_private_fields)

src/flag-definitions.h

@@ -193,7 +193,6 @@ DEFINE_IMPLICATION(harmony_class_fields, harmony_private_fields)
 
 // Features that are still work in progress (behind individual flags).
 #define HARMONY_INPROGRESS_BASE(V)                                 \
-  V(harmony_do_expressions, "harmony do-expressions")              \
   V(harmony_class_fields, "harmony fields in class literals")      \
   V(harmony_await_optimization, "harmony await taking 1 tick")     \
   V(harmony_regexp_sequence, "RegExp Unicode sequence properties") \

src/parsing/parser-base.h

@@ -241,7 +241,6 @@ class ParserBase {
         function_literal_id_(0),
         script_id_(script_id),
         allow_natives_(false),
-        allow_harmony_do_expressions_(false),
         allow_harmony_public_fields_(false),
         allow_harmony_static_fields_(false),
         allow_harmony_dynamic_import_(false),
@@ -256,7 +255,6 @@ class ParserBase {
   void set_allow_##name(bool allow) { allow_##name##_ = allow; }
 
   ALLOW_ACCESSORS(natives);
-  ALLOW_ACCESSORS(harmony_do_expressions);
   ALLOW_ACCESSORS(harmony_public_fields);
   ALLOW_ACCESSORS(harmony_static_fields);
   ALLOW_ACCESSORS(harmony_dynamic_import);
@@ -1146,8 +1144,6 @@ class ParserBase {
   // Magical syntax support.
   ExpressionT ParseV8Intrinsic();
 
-  ExpressionT ParseDoExpression();
-
   StatementT ParseDebuggerStatement();
 
   StatementT ParseExpressionOrLabelledStatement(
@@ -1446,7 +1442,6 @@ class ParserBase {
   int script_id_;
 
   bool allow_natives_;
-  bool allow_harmony_do_expressions_;
   bool allow_harmony_public_fields_;
   bool allow_harmony_static_fields_;
   bool allow_harmony_dynamic_import_;
@@ -1803,13 +1798,6 @@ ParserBase<Impl>::ParsePrimaryExpression() {
       }
       break;
 
-    case Token::DO:
-      if (allow_harmony_do_expressions()) {
-        BindingPatternUnexpectedToken();
-        return ParseDoExpression();
-      }
-      break;
-
     default:
       break;
   }
@@ -4515,17 +4503,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseV8Intrinsic() {
   return impl()->NewV8Intrinsic(name, args, pos);
 }
 
-template <typename Impl>
-typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseDoExpression() {
-  // AssignmentExpression ::
-  //     do '{' StatementList '}'
-
-  int pos = peek_position();
-  Consume(Token::DO);
-  BlockT block = ParseBlock(nullptr);
-  return impl()->RewriteDoExpression(block, pos);
-}
-
 template <typename Impl>
 typename ParserBase<Impl>::LazyParsingResult
 ParserBase<Impl>::ParseStatementList(StatementListT* body,

src/parsing/parser.cc

@@ -431,7 +431,6 @@ Parser::Parser(ParseInfo* info)
   allow_lazy_ = FLAG_lazy && info->allow_lazy_parsing() && !info->is_native() &&
                 info->extension() == nullptr && can_compile_lazily;
   set_allow_natives(FLAG_allow_natives_syntax || info->is_native());
-  set_allow_harmony_do_expressions(FLAG_harmony_do_expressions);
   set_allow_harmony_public_fields(FLAG_harmony_public_fields);
   set_allow_harmony_static_fields(FLAG_harmony_static_fields);
   set_allow_harmony_dynamic_import(FLAG_harmony_dynamic_import);
@@ -1549,16 +1548,6 @@ Expression* Parser::RewriteReturn(Expression* return_value, int pos) {
   return return_value;
 }
 
-Expression* Parser::RewriteDoExpression(Block* body, int pos) {
-  if (has_error()) return FailureExpression();
-  Variable* result = NewTemporary(ast_value_factory()->dot_result_string());
-  DoExpression* expr = factory()->NewDoExpression(body, result, pos);
-  if (!Rewriter::Rewrite(this, GetClosureScope(), expr, ast_value_factory())) {
-    return FailureExpression();
-  }
-  return expr;
-}
-
 Statement* Parser::RewriteSwitchStatement(SwitchStatement* switch_statement,
                                           Scope* scope) {
   // In order to get the CaseClauses to execute in their own lexical scope,

src/parsing/parser.h

@@ -257,7 +257,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
           parsing_module_, parsing_on_main_thread_);
 #define SET_ALLOW(name) reusable_preparser_->set_allow_##name(allow_##name());
       SET_ALLOW(natives);
-      SET_ALLOW(harmony_do_expressions);
       SET_ALLOW(harmony_public_fields);
       SET_ALLOW(harmony_static_fields);
       SET_ALLOW(harmony_dynamic_import);
@@ -387,8 +386,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
       ForStatement* loop, Statement* init, Expression* cond, Statement* next,
       Statement* body, Scope* inner_scope, const ForInfo& for_info);
 
-  Expression* RewriteDoExpression(Block* body, int pos);
-
   FunctionLiteral* ParseFunctionLiteral(
       const AstRawString* name, Scanner::Location function_name_location,
       FunctionNameValidity function_name_validity, FunctionKind kind,

src/parsing/preparser.h

@@ -1146,11 +1146,6 @@ class PreParser : public ParserBase<PreParser> {
                            function_scope);
   }
 
-  V8_INLINE PreParserExpression RewriteDoExpression(PreParserStatement body,
-                                                    int pos) {
-    return PreParserExpression::Default();
-  }
-
   // TODO(nikolaos): The preparser currently does not keep track of labels
   // and targets.
   V8_INLINE PreParserStatement

src/parsing/rewriter.cc

@@ -405,36 +405,5 @@ bool Rewriter::Rewrite(ParseInfo* info) {
   return true;
 }
 
-bool Rewriter::Rewrite(Parser* parser, DeclarationScope* closure_scope,
-                       DoExpression* expr, AstValueFactory* factory) {
-  DisallowHeapAllocation no_allocation;
-  DisallowHandleAllocation no_handles;
-  DisallowHandleDereference no_deref;
-
-  Block* block = expr->block();
-  DCHECK_EQ(closure_scope, closure_scope->GetClosureScope());
-  DCHECK(block->scope() == nullptr ||
-         block->scope()->GetClosureScope() == closure_scope);
-  ZonePtrList<Statement>* body = block->statements();
-  VariableProxy* result = expr->result();
-  Variable* result_var = result->var();
-
-  if (!body->is_empty()) {
-    Processor processor(parser, closure_scope, result_var, factory);
-    processor.Process(body);
-    if (processor.HasStackOverflow()) return false;
-
-    if (!processor.result_assigned()) {
-      AstNodeFactory* node_factory = processor.factory();
-      Expression* undef = node_factory->NewUndefinedLiteral(kNoSourcePosition);
-      Statement* completion = node_factory->NewExpressionStatement(
-          processor.SetResult(undef), expr->position());
-      body->Add(completion, factory->zone());
-    }
-  }
-  return true;
-}
-
-
 }  // namespace internal
 }  // namespace v8

src/parsing/rewriter.h

@@ -9,7 +9,6 @@ namespace v8 {
 namespace internal {
 
 class AstValueFactory;
-class DoExpression;
 class Isolate;
 class ParseInfo;
 class Parser;
@@ -25,15 +24,6 @@ class Rewriter {
   // Assumes code has been parsed and scopes have been analyzed.  Mutates the
   // AST, so the AST should not continue to be used in the case of failure.
   static bool Rewrite(ParseInfo* info);
-
-  // Rewrite a list of statements, using the same rules as a top-level program,
-  // to ensure identical behaviour of completion result.  The temporary is added
-  // to the closure scope of the do-expression, which matches the closure scope
-  // of the outer scope (the do-expression itself runs in a block scope, not a
-  // closure scope). This closure scope needs to be passed in since the
-  // do-expression could have dropped its own block scope.
-  static bool Rewrite(Parser* parser, DeclarationScope* closure_scope,
-                      DoExpression* expr, AstValueFactory* factory);
 };
 
 

test/cctest/compiler/test-run-bytecode-graph-builder.cc

@@ -2703,37 +2703,6 @@ void TestJumpWithConstantsAndWideConstants(size_t shard) {
 
 SHARD_TEST_BY_4(JumpWithConstantsAndWideConstants)
 
-TEST(BytecodeGraphBuilderDoExpressions) {
-  bool old_flag = FLAG_harmony_do_expressions;
-  FLAG_harmony_do_expressions = true;
-  HandleAndZoneScope scope;
-  Isolate* isolate = scope.main_isolate();
-  Factory* factory = isolate->factory();
-  ExpectedSnippet<0> snippets[] = {
-      {"var a = do {}; return a;", {factory->undefined_value()}},
-      {"var a = do { var x = 100; }; return a;", {factory->undefined_value()}},
-      {"var a = do { var x = 100; }; return a;", {factory->undefined_value()}},
-      {"var a = do { var x = 100; x++; }; return a;",
-       {handle(Smi::FromInt(100), isolate)}},
-      {"var i = 0; for (; i < 5;) { i = do { if (i == 3) { break; }; i + 1; }};"
-       "return i;",
-       {handle(Smi::FromInt(3), isolate)}},
-  };
-
-  for (size_t i = 0; i < arraysize(snippets); i++) {
-    ScopedVector<char> script(1024);
-    SNPrintF(script, "function %s() { %s }\n%s();", kFunctionName,
-             snippets[i].code_snippet, kFunctionName);
-
-    BytecodeGraphTester tester(isolate, script.start());
-    auto callable = tester.GetCallable<>();
-    Handle<Object> return_value = callable().ToHandleChecked();
-    CHECK(return_value->SameValue(*snippets[i].return_value()));
-  }
-
-  FLAG_harmony_do_expressions = old_flag;
-}
-
 TEST(BytecodeGraphBuilderWithStatement) {
   HandleAndZoneScope scope;
   Isolate* isolate = scope.main_isolate();

test/cctest/interpreter/generate-bytecode-expectations.cc

@@ -446,7 +446,6 @@ void GenerateExpectationsFile(std::ostream& stream,  // NOLINT
     printer.set_test_function_name(options.test_function_name());
   }
 
-  if (options.do_expressions()) i::FLAG_harmony_do_expressions = true;
   if (options.public_fields()) i::FLAG_harmony_public_fields = true;
   if (options.private_fields()) i::FLAG_harmony_private_fields = true;
   if (options.static_fields()) i::FLAG_harmony_static_fields = true;
@@ -457,7 +456,6 @@ void GenerateExpectationsFile(std::ostream& stream,  // NOLINT
     printer.PrintExpectation(stream, snippet);
   }
 
-  i::FLAG_harmony_do_expressions = false;
   i::FLAG_harmony_public_fields = false;
   i::FLAG_harmony_private_fields = false;
   i::FLAG_harmony_static_fields = false;
@@ -509,7 +507,6 @@ void PrintUsage(const char* exec_path) {
          "  --test-function-name=foo  "
          "Specify the name of the test function.\n"
          "  --top-level   Process top level code, not the top-level function.\n"
-         "  --do-expressions  Enable harmony_do_expressions flag.\n"
          "  --public-fields  Enable harmony_public_fields flag.\n"
          "  --private-fields  Enable harmony_private_fields flag.\n"
          "  --static-fields  Enable harmony_static_fields flag.\n"

test/cctest/interpreter/test-bytecode-generator.cc

@@ -2504,26 +2504,6 @@ TEST(LetVariableContextSlot) {
                      LoadGolden("LetVariableContextSlot.golden")));
 }
 
-TEST(DoExpression) {
-  bool old_flag = FLAG_harmony_do_expressions;
-  FLAG_harmony_do_expressions = true;
-
-  InitializedIgnitionHandleScope scope;
-  BytecodeExpectationsPrinter printer(CcTest::isolate());
-  const char* snippets[] = {
-      "var a = do { }; return a;\n",
-
-      "var a = do { var x = 100; }; return a;\n",
-
-      "while(true) { var a = 10; a = do { ++a; break; }; a = 20; }\n",
-  };
-
-  CHECK(CompareTexts(BuildActual(printer, snippets),
-                     LoadGolden("DoExpression.golden")));
-
-  FLAG_harmony_do_expressions = old_flag;
-}
-
 TEST(WithStatement) {
   InitializedIgnitionHandleScope scope;
   BytecodeExpectationsPrinter printer(CcTest::isolate());

test/cctest/interpreter/test-interpreter.cc

@@ -4630,37 +4630,6 @@ TEST(InterpreterWideParametersSummation) {
   }
 }
 
-TEST(InterpreterDoExpression) {
-  bool old_flag = FLAG_harmony_do_expressions;
-  FLAG_harmony_do_expressions = true;
-
-  HandleAndZoneScope handles;
-  Isolate* isolate = handles.main_isolate();
-  Factory* factory = isolate->factory();
-
-  std::pair<const char*, Handle<Object>> do_expr[] = {
-      {"var a = do {}; return a;", factory->undefined_value()},
-      {"var a = do { var x = 100; }; return a;", factory->undefined_value()},
-      {"var a = do { var x = 100; }; return a;", factory->undefined_value()},
-      {"var a = do { var x = 100; x++; }; return a;",
-       handle(Smi::FromInt(100), isolate)},
-      {"var i = 0; for (; i < 5;) { i = do { if (i == 3) { break; }; i + 1; }};"
-       "return i;",
-       handle(Smi::FromInt(3), isolate)},
-  };
-
-  for (size_t i = 0; i < arraysize(do_expr); i++) {
-    std::string source(InterpreterTester::SourceForBody(do_expr[i].first));
-    InterpreterTester tester(isolate, source.c_str());
-    auto callable = tester.GetCallable<>();
-
-    Handle<i::Object> return_value = callable().ToHandleChecked();
-    CHECK(return_value->SameValue(*do_expr[i].second));
-  }
-
-  FLAG_harmony_do_expressions = old_flag;
-}
-
 TEST(InterpreterWithStatement) {
   HandleAndZoneScope handles;
   Isolate* isolate = handles.main_isolate();

test/cctest/test-parsing.cc

@@ -1510,7 +1510,6 @@ enum ParserFlag {
   kAllowHarmonyStaticFields,
   kAllowHarmonyDynamicImport,
   kAllowHarmonyImportMeta,
-  kAllowHarmonyDoExpressions,
   kAllowHarmonyNumericSeparator
 };
 
@@ -1527,7 +1526,6 @@ void SetGlobalFlags(i::EnumSet<ParserFlag> flags) {
   i::FLAG_harmony_static_fields = flags.Contains(kAllowHarmonyStaticFields);
   i::FLAG_harmony_dynamic_import = flags.Contains(kAllowHarmonyDynamicImport);
   i::FLAG_harmony_import_meta = flags.Contains(kAllowHarmonyImportMeta);
-  i::FLAG_harmony_do_expressions = flags.Contains(kAllowHarmonyDoExpressions);
   i::FLAG_harmony_numeric_separator =
       flags.Contains(kAllowHarmonyNumericSeparator);
 }
@@ -1544,8 +1542,6 @@ void SetParserFlags(i::PreParser* parser, i::EnumSet<ParserFlag> flags) {
       flags.Contains(kAllowHarmonyDynamicImport));
   parser->set_allow_harmony_import_meta(
       flags.Contains(kAllowHarmonyImportMeta));
-  parser->set_allow_harmony_do_expressions(
-      flags.Contains(kAllowHarmonyDoExpressions));
   parser->set_allow_harmony_numeric_separator(
       flags.Contains(kAllowHarmonyNumericSeparator));
 }
@@ -2691,29 +2687,6 @@ TEST(OptionalCatchBinding) {
   RunParserSyncTest(context_data, statement_data, kSuccess);
 }
 
-TEST(OptionalCatchBindingInDoExpression) {
-  // This is an edge case no otherwise hit: a catch scope in a parameter
-  // expression which needs its own scope.
-  // clang-format off
-  const char* context_data[][2] = {
-    {"((x = (eval(''), do {", "}))=>{})()"},
-    { nullptr, nullptr }
-  };
-
-  const char* statement_data[] = {
-    "try { } catch { }",
-    "try { } catch { } finally { }",
-    "try { let e; } catch { let e; }",
-    "try { let e; } catch { let e; } finally { let e; }",
-    nullptr
-  };
-  // clang-format on
-
-  static const ParserFlag do_and_catch_flags[] = {kAllowHarmonyDoExpressions};
-  RunParserSyncTest(context_data, statement_data, kSuccess, nullptr, 0,
-                    do_and_catch_flags, arraysize(do_and_catch_flags));
-}
-
 TEST(ErrorsRegexpLiteral) {
   const char* context_data[][2] = {{"var r = ", ""}, {nullptr, nullptr}};
 

test/mjsunit/es6/classes.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --harmony-do-expressions
+// Flags: --allow-natives-syntax
 
 (function TestBasics() {
   var C = class C {}
@@ -1038,31 +1038,6 @@ function testClassRestrictedProperties(C) {
 
 (function testReturnFromClassLiteral() {
 
-  function usingDoExpressionInBody() {
-    let x = 42;
-    let dummy = function() {x};
-    try {
-      class C {
-        dummy() {C}
-        [do {return}]() {}
-      };
-    } finally {
-      return x;
-    }
-  }
-  assertEquals(42, usingDoExpressionInBody());
-
-  function usingDoExpressionInExtends() {
-    let x = 42;
-    let dummy = function() {x};
-    try {
-      class C extends (do {return}) { dummy() {C} };
-    } finally {
-      return x;
-    }
-  }
-  assertEquals(42, usingDoExpressionInExtends());
-
   function usingYieldInBody() {
     function* foo() {
       class C {

test/mjsunit/harmony/default-parameter-do-expression.js

-// Copyright 2016 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.
-
-// Flags: --harmony-do-expressions --nolazy
-
-function hoist_unique_do_var() {
-  var f = (y = do { var unique = 3 }) => unique;
-  assertEquals(3, f());
-  assertThrows(() => unique, ReferenceError);
-}
-hoist_unique_do_var();
-
-function hoist_duplicate_do_var() {
-  var duplicate = 100;
-  var f = (y = do { var duplicate = 3 }) => duplicate;
-  assertEquals(3, f());
-  // TODO(verwaest): The {duplicate} declarations were invalidly merged.
-  assertEquals(3, duplicate);
-}
-hoist_duplicate_do_var();

test/mjsunit/harmony/do-expressions-arrow-param-scope.js

-// Copyright 2017 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.
-
-// Flags: --harmony-do-expressions
-
-(function testBasic() {
-  let f = (x = eval("var z = 42; z"), y = do { 43 }) => x + y;
-  assertEquals(85, f());
-})();
-
-(function testReturnParam() {
-  let f = (x = eval("var z = 42; z"), y = do { x }) => x + y;
-  assertEquals(84, f());
-})();
-
-(function testCaptureParam() {
-  let f = (x = eval("var z = 42; z"), y = do { () => x }) => x + y();
-  assertEquals(84, f());
-})();
-
-(function testScoped() {
-  let f = (x = eval("var z = 42; z"), y = do { let z; x }) => x + y;
-  assertEquals(84, f());
-})();
-
-(function testCaptureScoped() {
-  let f = (x = eval("var z = 42; z"), y = do { let z; () => x }) => x + y();
-  assertEquals(84, f());
-})();
-
-(function testCaptureOuter() {
-  let z = 44;
-  let f = (x = eval("var z = 42; z"), y = do { () => z }) => x + y();
-  assertEquals(86, f())
-})();
-
-(function testCaptureOuterScoped() {
-  let z = 44;
-  let f = (x = eval("var z = 42; z"), y = do { let q; () => z }) => x + y();
-  assertEquals(86, f())
-})();
-
-(function testWith() {
-  let f = (x = eval("var z = 42; z"),
-           y = do {
-             with ({foo: "bar"}) {
-               () => x }
-           }) => x + y();
-  assertEquals(84, f())
-})();
-
-(function testTry() {
-  let f = (x = eval("var z = 42; z"),
-           y = do {
-             try { () => x }
-             catch (e) { }
-           }) => x + y();
-  assertEquals(84, f())
-})();
-
-(function testCatch() {
-  let f = (x = eval("var z = 42; z"),
-           y = do {
-             try { throw 42 }
-             catch (e) { () => x }
-           }) => x + y();
-  assertEquals(84, f())
-})();
-
-(function testFinally() {
-  let z = 44;
-  let q;
-  let f = (x = eval("var z = 42; z"),
-           y = do {
-             try { }
-             catch (e) { }
-             finally { q = () => z }
-             q;
-           }) => x + y();
-  assertEquals(86, f())
-})();
-
-(function testFinallyThrow() {
-  let z = 44;
-  let q;
-  let f = (x = eval("var z = 42; z"),
-           y = do {
-             try { throw 42; }
-             catch (e) { }
-             finally { q = () => z }
-             q;
-           }) => x + y();
-  assertEquals(86, f())
-})();

test/mjsunit/harmony/do-expressions-control.js

-// Copyright 2016 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.
-
-// Flags: --allow-natives-syntax --harmony-do-expressions
-
-(function TestDoForInDoBreak() {
-  function f(o, i) {
-    var a = "result@" + do {
-      var r = "(";
-      for (var x in o) {
-        var b = "end@" + do {
-          if (x == i) { break } else { r += o[x]; x }
-        }
-      }
-      r + ")";
-    }
-    return a + "," + b;
-  }
-  assertEquals("result@(3),end@0", f([3], 2));
-  assertEquals("result@(35),end@1", f([3,5], 2));
-  assertEquals("result@(35),end@1", f([3,5,7], 2));
-  assertEquals("result@(35),end@1", f([3,5,7,9], 2));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals("result@(3),end@0", f([3], 2));
-  assertEquals("result@(35),end@1", f([3,5], 2));
-  assertEquals("result@(35),end@1", f([3,5,7], 2));
-  assertEquals("result@(35),end@1", f([3,5,7,9], 2));
-})();
-
-(function TestDoForInDoContinue() {
-  function f(o, i) {
-    var a = "result@" + do {
-      var r = "("
-      for (var x in o) {
-        var b = "end@" + do {
-          if (x == i) { continue } else { r += o[x]; x }
-        }
-      }
-      r + ")"
-    }
-    return a + "," + b
-  }
-  assertEquals("result@(3),end@0", f([3], 2));
-  assertEquals("result@(35),end@1", f([3,5], 2));
-  assertEquals("result@(35),end@1", f([3,5,7], 2));
-  assertEquals("result@(359),end@3", f([3,5,7,9], 2));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals("result@(3),end@0", f([3], 2));
-  assertEquals("result@(35),end@1", f([3,5], 2));
-  assertEquals("result@(35),end@1", f([3,5,7], 2));
-  assertEquals("result@(359),end@3", f([3,5,7,9], 2));
-})();
-
-(function TestDoForNestedWithTargetLabels() {
-  function f(mode) {
-    var loop = true;
-    var head = "<";
-    var tail = ">";
-    var middle =
-    "1" + do { loop1: for(; loop; head += "A") {
-      "2" + do { loop2: for(; loop; head += "B") {
-        "3" + do { loop3: for(; loop; head += "C") {
-          "4" + do { loop4: for(; loop; head += "D") {
-            "5" + do { loop5: for(; loop; head += "E") {
-              "6" + do { loop6: for(; loop; head += "F") {
-                loop = false;
-                switch (mode) {
-                  case "b1": break loop1;
-                  case "b2": break loop2;
-                  case "b3": break loop3;
-                  case "b4": break loop4;
-                  case "b5": break loop5;
-                  case "b6": break loop6;
-                  case "c1": continue loop1;
-                  case "c2": continue loop2;
-                  case "c3": continue loop3;
-                  case "c4": continue loop4;
-                  case "c5": continue loop5;
-                  case "c6": continue loop6;
-                  default: "7";
-                }
-              }}
-            }}
-          }}
-        }}
-      }}
-    }}
-    return head + middle + tail;
-  }
-  function test() {
-    assertEquals(      "<1undefined>",      f("b1"));
-    assertEquals(     "<A1undefined>",      f("c1"));
-    assertEquals(     "<A12undefined>",     f("b2"));
-    assertEquals(    "<BA12undefined>",     f("c2"));
-    assertEquals(    "<BA123undefined>",    f("b3"));
-    assertEquals(   "<CBA123undefined>",    f("c3"));
-    assertEquals(   "<CBA1234undefined>",   f("b4"));
-    assertEquals(  "<DCBA1234undefined>",   f("c4"));
-    assertEquals(  "<DCBA12345undefined>",  f("b5"));
-    assertEquals( "<EDCBA12345undefined>",  f("c5"));
-    assertEquals( "<EDCBA123456undefined>", f("b6"));
-    assertEquals("<FEDCBA123456undefined>", f("c6"));
-    assertEquals("<FEDCBA1234567>",         f("xx"));
-  }
-  test();
-  %OptimizeFunctionOnNextCall(f);
-  test();
-})();

test/mjsunit/harmony/do-expressions.js

-// 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.
-
-// Flags: --harmony-do-expressions --allow-natives-syntax --no-always-opt --opt
-
-function returnValue(v) { return v; }
-function MyError() {}
-var global = this;
-
-function TestBasic() {
-  // Looping and lexical declarations
-  assertEquals(512, returnValue(do {
-    let n = 2;
-    for (let i = 0; i < 4; i++) n <<= 2;
-  }));
-
-  // Strings do the right thing
-  assertEquals("spooky halloween", returnValue(do {
-    "happy halloween".replace('happy', 'spooky');
-  }));
-
-  // Do expressions with no completion produce an undefined value
-  assertEquals(undefined, returnValue(do {}));
-  assertEquals(undefined, returnValue(do { var x = 99; }));
-  assertEquals(undefined, returnValue(do { function f() {}; }));
-  assertEquals(undefined, returnValue(do { let z = 33; }));
-
-  // Propagation of exception
-  assertThrows(function() {
-    (do {
-      throw new MyError();
-      "potatoes";
-    });
-  }, MyError);
-
-  assertThrows(function() {
-    return do {
-      throw new MyError();
-      "potatoes";
-    };
-  }, MyError);
-
-  // Return value within do-block overrides `return |do-expression|`
-  assertEquals("inner-return", (function() {
-    return "outer-return" + do {
-      return "inner-return";
-      "";
-    };
-  })());
-
-  var count = 0, n = 1;
-  // Breaking out |do-expression|
-  assertEquals(3, (function() {
-    for (var i = 0; i < 10; ++i) (count += 2 * do { if (i === 3) break; ++n });
-    return i;
-  })());
-  // (2 * 2) + (2 * 3) + (2 * 4)
-  assertEquals(18, count);
-
-  // Continue in |do-expression|
-  count = 0, n = 1;
-  assertEquals([1, 3, 5, 7, 9], (function() {
-    var values = [];
-    for (var i = 0; i < 10; ++i) {
-      count += 2 * (do {
-        if ((i & 1) === 0) continue;
-        values.push(i);
-        ++n;
-      }) + 1;
-    }
-    // (2*2) + 1 + (2*3) + 1 + (2*4) + 1 + (2*5) + 1 + (2*6) + 1
-    return values;
-  })());
-  assertEquals(count, 45);
-
-  assertThrows("(do { break; });", SyntaxError);
-  assertThrows("(do { continue; });", SyntaxError);
-
-  // Real-world use case for desugaring
-  var array = [1, 2, 3, 4, 5], iterable = [6, 7, 8,9];
-  assertEquals([1, 2, 3, 4, 5, 6, 7, 8, 9], do {
-    for (var element of iterable) array.push(element);
-    array;
-  });
-
-  // Nested do-expressions
-  assertEquals(125, do { (do { (do { 5 * 5 * 5 }) }) });
-
-  // Directives are not honoured
-  (do {
-    "use strict";
-    foo = 80;
-    assertEquals(foo, 80);
-  });
-
-  // Non-empty operand stack testing
-  var O = {
-    method1() {
-      let x = 256;
-      return x + do {
-        for (var i = 0; i < 4; ++i) x += i;
-      } + 17;
-    },
-    method2() {
-      let x = 256;
-      this.reset();
-      return x + do {
-        for (var i = 0; i < this.length(); ++i) x += this.index() * 2;
-      };
-    },
-    _index: 0,
-    index() {
-      return ++this._index;
-    },
-    _length: 4,
-    length() { return this._length; },
-    reset() { this._index = 0; }
-  };
-  assertEquals(535, O["method" + do { 1 } + ""]());
-  assertEquals(532, O["method" + do { ({ valueOf() { return "2"; } }); }]());
-  assertEquals(532, O[
-      do { let s = ""; for (let c of "method") s += c; } + "2"]());
-}
-TestBasic();
-
-
-function TestDeoptimization1() {
-  function f(v) {
-    return 88 + do {
-      v.a * v.b + v.c;
-    };
-  }
-
-  var o1 = {};
-  o1.a = 10;
-  o1.b = 5;
-  o1.c = 50;
-
-  var o2 = {};
-  o2.c = 100;
-  o2.a = 10;
-  o2.b = 10;
-
-  assertEquals(188, f(o1));
-  assertEquals(188, f(o1));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals(188, f(o1));
-  assertOptimized(f);
-  assertEquals(288, f(o2));
-  assertUnoptimized(f);
-  assertEquals(288, f(o2));
-}
-TestDeoptimization1();
-
-
-function TestInParameterInitializers() {
-  var first_name = "George";
-  var last_name = "Jetson";
-  function fn1(name = do { first_name + " " + last_name }) {
-    return name;
-  }
-  assertEquals("George Jetson", fn1());
-
-  var _items = [1, 2, 3, NaN, 4, 5];
-  function fn2(items = do {
-    let items = [];
-    for (var el of _items) {
-      if (el !== el) {
-        items;
-        break;
-      }
-      items.push(el), items;
-    }
-  }) {
-    return items;
-  }
-  assertEquals([1, 2, 3], fn2());
-
-  function thrower() { throw new MyError(); }
-  function fn3(exception = do {  try { thrower(); } catch (e) { e } }) {
-    return exception;
-  }
-  assertDoesNotThrow(fn3);
-  assertInstanceof(fn3(), MyError);
-
-  function fn4(exception = do { throw new MyError() }) {}
-  function catcher(fn) {
-    try {
-      fn();
-      assertUnreachable("fn() initializer should throw");
-    } catch (e) {
-      assertInstanceof(e, MyError);
-    }
-  }
-  catcher(fn4);
-}
-TestInParameterInitializers();
-
-
-function TestWithEval() {
-  (function sloppy1() {
-    assertEquals(do { eval("var x = 5"), x }, 5);
-    assertEquals(x, 5);
-  })();
-
-  assertThrows(function strict1() {
-    "use strict";
-    (do { eval("var x = 5"), x }, 5);
-  }, ReferenceError);
-
-  assertThrows(function strict2() {
-    (do { eval("'use strict'; var x = 5"), x }, 5);
-  }, ReferenceError);
-}
-TestWithEval();
-
-
-function TestHoisting() {
-  (do { var a = 1; });
-  assertEquals(a, 1);
-  assertEquals(global.a, undefined);
-
-  (do {
-    for (let it of [1, 2, 3, 4, 5]) {
-      var b = it;
-    }
-  });
-  assertEquals(b, 5);
-  assertEquals(global.b, undefined);
-
-  {
-    let x = 1
-
-    // TODO(caitp): ensure VariableStatements in |do-expressions| in parameter
-    // initializers, are evaluated in the same VariableEnvironment as they would
-    // be for eval().
-    // function f1(a = do { var x = 2 }, b = x) { return b }
-    // assertEquals(1, f1())
-
-    // function f2(a = x, b = do { var x = 2 }) { return a }
-    // assertEquals(1, f2())
-
-    function f3({a = do { var x = 2 }, b = x}) { return b }
-    assertEquals(2, f3({}))
-
-    function f4({a = x, b = do { var x = 2 }}) { return b }
-    assertEquals(undefined, f4({}))
-
-    function f5(a = do { var y = 0 }) {}
-    assertThrows(() => y, ReferenceError)
-  }
-
-  // TODO(caitp): Always block-scope function declarations in |do| expressions
-  //(do {
-  //  assertEquals(true, inner_func());
-  //  function inner_func() { return true; }
-  //});
-  //assertThrows(function() { return innerFunc(); }, ReferenceError);
-}
-TestHoisting();
-
-
-// v8:4661
-
-function tryFinallySimple() { (do { try {} finally {} }); }
-tryFinallySimple();
-tryFinallySimple();
-tryFinallySimple();
-tryFinallySimple();
-
-var finallyRanCount = 0;
-function tryFinallyDoExpr() {
-  return (do {
-    try {
-      throw "BOO";
-    } catch (e) {
-      "Caught: " + e + " (" + finallyRanCount + ")"
-    } finally {
-      ++finallyRanCount;
-    }
-  });
-}
-assertEquals("Caught: BOO (0)", tryFinallyDoExpr());
-assertEquals(1, finallyRanCount);
-assertEquals("Caught: BOO (1)", tryFinallyDoExpr());
-assertEquals(2, finallyRanCount);
-assertEquals("Caught: BOO (2)", tryFinallyDoExpr());
-assertEquals(3, finallyRanCount);
-assertEquals("Caught: BOO (3)", tryFinallyDoExpr());
-assertEquals(4, finallyRanCount);
-
-
-function TestOSR() {
-  var numbers = do {
-    let nums = [];
-    for (let i = 0; i < 1000; ++i) {
-      let value = (Math.random() * 100) | 0;
-      nums.push(value === 0 ? 1 : value), nums;
-    }
-  };
-  assertEquals(numbers.length, 1000);
-}
-
-for (var i = 0; i < 64; ++i) TestOSR();

test/mjsunit/harmony/generators.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-do-expressions --allow-natives-syntax
+// Flags: --allow-natives-syntax
 
 
 function MaybeOptimizeOrDeoptimize(f) {
@@ -428,14 +428,6 @@ function Throw(generator, ...args) {
   assertEquals({value: 4, done: false}, Next(g));
 }
 
-{
-  function* foo() { yield 2; (do {yield 3}) + 42; yield 4 }
-  g = foo();
-  assertEquals({value: 2, done: false}, Next(g));
-  assertEquals({value: 3, done: false}, Next(g));
-  assertEquals({value: 4, done: false}, Next(g));
-}
-
 {
   function* foo() { yield 2; return (yield 3) + 42; yield 4 }
   g = foo();

test/mjsunit/harmony/regress/regress-4658.js

-// 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.
-
-// Flags: --harmony-do-expressions
-
-(function testWithSimpleLoopVariable() {
-  var f = (x, y = (do { var s=0; for (var e of x) s += e; s; })) => y*(y+1);
-  var result = f([1,2,3]);  // core dump here, if not fixed.
-  assertEquals(result, 42);
-})();
-
-(function testWithComplexLoopVariable() {
-  var f = (x, i=x[0]-1, a=[],
-           y = (do { var s=0;
-                     for (a[i] of x) s += a[i++];
-                     s;
-                   })) => y*(a[0]+a[1]*a[2]);
-  var result = f([1,2,3]);  // core dump here, if not fixed.
-  assertEquals(result, 42);
-})();

test/mjsunit/harmony/regress/regress-4755.js

-// Copyright 2016 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.
-
-// Flags: --allow-natives-syntax --harmony-do-expressions
-
-(function DoTryCatchInsideBinop() {
-  function f(a, b) {
-    return a + do { try { throw "boom" } catch(e) { b } }
-  }
-  assertEquals(3, f(1, 2));
-  assertEquals(3, f(1, 2));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals(3, f(1, 2));
-})();
-
-(function DoTryCatchInsideCall() {
-  function f(a, b) {
-    return Math.max(a, do { try { throw a } catch(e) { e + b } })
-  }
-  assertEquals(3, f(1, 2));
-  assertEquals(3, f(1, 2));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals(3, f(1, 2));
-})();
-
-(function DoTryCatchInsideTry() {
-  function f(a, b) {
-    try { return do { try { throw a } catch(e) { e + b } } } catch(e) {}
-  }
-  assertEquals(3, f(1, 2));
-  assertEquals(3, f(1, 2));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals(3, f(1, 2));
-})();
-
-(function DoTryCatchInsideFinally() {
-  function f(a, b) {
-    try {} finally { return do { try { throw a } catch(e) { e + b } } }
-  }
-  assertEquals(3, f(1, 2));
-  assertEquals(3, f(1, 2));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals(3, f(1, 2));
-})();

test/mjsunit/harmony/regress/regress-4904.js

-// 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.
-
-// Flags: --harmony-do-expressions
-
-(function testCatchScopeInDoExpression() {
-  var f = (s = 17, y = do { try { throw 25; } catch(e) { s += e; }; }) => s;
-  var result = f();
-  assertEquals(result, 42);
-})();
-
-(function testCatchScopeInDoExpression() {
-  var f = (s = 17, y = do { let t; try { throw 25; } catch(e) { s += e; }; }) => s;
-  var result = f();
-  assertEquals(result, 42);
-})();
-
-(function testCatchScopeInDoExpression() {
-  let t1;
-  var f = (s = 17, y = do { let t2; try { throw 25; } catch(e) { s += e; }; }) => s;
-  var result = f();
-  assertEquals(result, 42);
-})();

test/mjsunit/harmony/regress/regress-546967.js

-// 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.
-//
-// Flags: --harmony-do-expressions --allow-natives-syntax
-
-function func1() {
-  for (var i = 0; i < 64; ++i) func2();
-}
-
-%OptimizeFunctionOnNextCall(func1);
-func1();
-
-function func2() {
-  var v = do {};
-}

test/mjsunit/harmony/regress/regress-crbug-578038.js

-// 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.
-
-// Flags: --harmony-do-expressions
-
-(function testWithoutOtherLiteral() {
-  var result = ((x = [...[42]]) => x)();
-  assertEquals(result, [42]);
-})();
-
-(function testWithSomeOtherLiteral() {
-  []; // important: an array literal before the arrow function
-  var result = ((x = [...[42]]) => x)();  // will core dump, if not fixed.
-  assertEquals(result, [42]);
-})();

test/mjsunit/regress/regress-crbug-546968.js

-// 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.
-
-// Flags: --allow-natives-syntax --harmony-do-expressions
-
-function f() {
-  print(
-    do {
-      for (var i = 0; i < 10; i++) { if (i == 5) %OptimizeOsr(); }
-    }
-  );
-}
-f();

test/mjsunit/regress/regress-osr-in-case-label.js

-// 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.
-
-// Flags: --allow-natives-syntax --harmony-do-expressions
-
-function f(x) {
-  switch (x) {
-    case 1: return "one";
-    case 2: return "two";
-    case do { for (var i = 0; i < 10; i++) { if (i == 5) %OptimizeOsr(); } }:
-    case 3: return "WAT";
-  }
-}
-
-assertEquals("one", f(1));
-assertEquals("two", f(2));
-assertEquals("WAT", f(3));

test/mjsunit/regress/regress-osr-in-literal.js

-// 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.
-
-// Flags: --allow-natives-syntax --harmony-do-expressions
-
-"use strict";
-
-var p = {};
-var testCases = [
-  { s:"[1, do { _OSR_ 2 }, 3]",                      r:[1, 2, 3] },
-  { s:"[1, ...[2], do { _OSR_ 3 }, 4]",              r:[1, 2, 3, 4] },
-  { s:"[1, ...do { _OSR_ [2,3] }, 4]",               r:[1, 2, 3, 4] },
-  { s:"{ a:do { _OSR_ 1 } }",                        r:{ a:1 } },
-  { s:"{ a:do { _OSR_ 2 }, __proto__:p }",           r:{ a:2, __proto__:p } },
-  { s:"{ a:do { _OSR_ 3 }, get b() { return 4; } }", r:{ a:3, b:4 } },
-  { s:"{ [do { _OSR_ 'b' }]: 3 }",                   r:{ b:3 } },
-  { s:"{ [do { _OSR_ 'b' }]: 3, c: 4 }",             r:{ b:3, c:4 } },
-  { s:"{ [do { _OSR_ 'b' }]: 3, __proto__:p }",      r:{ b:3, __proto__:p } },
-  { s:"{ get [do { _OSR_ 'c' }]() { return 4; } }",  r:{ c:4 } },
-  { s:"class { [do { _OSR_ 'f' }]() {} }" },
-  { s:"class { [do { _OSR_ 'f' }]() {}; g() {} }" },
-];
-
-for (var i = 0; i < testCases.length; ++i) {
-  var source = "(function f" + i + "(x) { return " + testCases[i].s + "})";
-  var osr = "for (var i = 0; i < 10; i++) { if (i == 5) %OptimizeOsr(); }";
-  var result = eval(source.replace("_OSR_", osr))();
-  if (testCases[i].r) assertEquals(testCases[i].r, result);
-}