[es8] Remove syntactic tail calls support.

BUG=v8:4915

Review-Url: https://codereview.chromium.org/2372513003
Cr-Commit-Position: refs/heads/master@{#39808}

src/bootstrapper.cc

@@ -2845,7 +2845,6 @@ EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_regexp_lookbehind)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_regexp_named_captures)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_regexp_property)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_function_sent)
-EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_explicit_tailcalls)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_tailcalls)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_restrictive_declarations)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_string_padding)
@@ -3428,7 +3427,6 @@ bool Genesis::InstallNatives(GlobalContextType context_type) {
 
 
 bool Genesis::InstallExperimentalNatives() {
-  static const char* harmony_explicit_tailcalls_natives[] = {nullptr};
   static const char* harmony_tailcalls_natives[] = {nullptr};
   static const char* harmony_sharedarraybuffer_natives[] = {
       "native harmony-atomics.js", NULL};

src/flag-definitions.h

@@ -198,7 +198,6 @@ DEFINE_IMPLICATION(es_staging, move_object_start)
   V(harmony_function_sent, "harmony function.sent")                     \
   V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")             \
   V(harmony_simd, "harmony simd")                                       \
-  V(harmony_explicit_tailcalls, "harmony explicit tail calls")          \
   V(harmony_do_expressions, "harmony do-expressions")                   \
   V(harmony_restrictive_generators,                                     \
     "harmony restrictions on generator declarations")                   \

src/messages.h

@@ -593,19 +593,10 @@ class ErrorUtils : public AllStatic {
   T(UnexpectedEOS, "Unexpected end of input")                                  \
   T(UnexpectedFunctionSent,                                                    \
     "function.sent expression is not allowed outside a generator")             \
-  T(UnexpectedInsideTailCall, "Unexpected expression inside tail call")        \
   T(UnexpectedReserved, "Unexpected reserved word")                            \
   T(UnexpectedStrictReserved, "Unexpected strict mode reserved word")          \
   T(UnexpectedSuper, "'super' keyword unexpected here")                        \
-  T(UnexpectedSloppyTailCall,                                                  \
-    "Tail call expressions are not allowed in non-strict mode")                \
   T(UnexpectedNewTarget, "new.target expression is not allowed here")          \
-  T(UnexpectedTailCall, "Tail call expression is not allowed here")            \
-  T(UnexpectedTailCallInCatchBlock,                                            \
-    "Tail call expression in catch block when finally block is also present")  \
-  T(UnexpectedTailCallInForInOf, "Tail call expression in for-in/of body")     \
-  T(UnexpectedTailCallInTryBlock, "Tail call expression in try block")         \
-  T(UnexpectedTailCallOfEval, "Tail call of a direct eval is not allowed")     \
   T(UnexpectedTemplateString, "Unexpected template string")                    \
   T(UnexpectedToken, "Unexpected token %")                                     \
   T(UnexpectedTokenIdentifier, "Unexpected identifier")                        \

src/parsing/parser.cc

@@ -3550,7 +3550,6 @@ Expression* Parser::ParseClassLiteral(const AstRawString* name,
     block_state.set_start_position(scanner()->location().end_pos);
     ExpressionClassifier extends_classifier(this);
     extends = ParseLeftHandSideExpression(CHECK_OK);
-    CheckNoTailCallExpressions(CHECK_OK);
     RewriteNonPattern(CHECK_OK);
     impl()->AccumulateFormalParameterContainmentErrors();
   } else {
@@ -4221,12 +4220,7 @@ void Parser::MarkCollectedTailCallExpressions() {
   const ZoneList<Expression*>& tail_call_expressions =
       function_state_->tail_call_expressions().expressions();
   for (int i = 0; i < tail_call_expressions.length(); ++i) {
-    Expression* expression = tail_call_expressions[i];
-    // If only FLAG_harmony_explicit_tailcalls is enabled then expression
-    // must be a Call expression.
-    DCHECK(FLAG_harmony_tailcalls || !FLAG_harmony_explicit_tailcalls ||
-           expression->IsCall());
-    MarkTailPosition(expression);
+    MarkTailPosition(tail_call_expressions[i]);
   }
 }
 

src/parsing/preparser.cc

@@ -278,7 +278,6 @@ PreParserExpression PreParser::ParseClassLiteral(
   if (has_extends) {
     ExpressionClassifier extends_classifier(this);
     ParseLeftHandSideExpression(CHECK_OK);
-    CheckNoTailCallExpressions(CHECK_OK);
     ValidateExpression(CHECK_OK);
     impl()->AccumulateFormalParameterContainmentErrors();
   }

test/message/syntactic-tail-call-generator.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-explicit-tailcalls
-
-function f() {
-  return 1;
-}
-
-function* g() {
-  'use strict';
-  return continue f();
-}

test/message/syntactic-tail-call-generator.out

-*%(basename)s:13: SyntaxError: Tail call expression is not allowed here
-  return continue f();
-                  ^^^
-SyntaxError: Tail call expression is not allowed here 

test/message/syntactic-tail-call-in-binop-lhs.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  return   continue f()   - a ;
-}

test/message/syntactic-tail-call-in-binop-lhs.out

-*%(basename)s:13: SyntaxError: Tail call expression is not allowed here
-  return   continue f()   - a ;
-           ^^^^^^^^^^^^
-SyntaxError: Tail call expression is not allowed here

test/message/syntactic-tail-call-in-binop-rhs.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  return b + continue f()  ;
-}

test/message/syntactic-tail-call-in-binop-rhs.out

-*%(basename)s:13: SyntaxError: Tail call expression is not allowed here
-  return b + continue f()  ;
-             ^^^^^^^^^^^^
-SyntaxError: Tail call expression is not allowed here

test/message/syntactic-tail-call-in-comma.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  return 1, 2, 3,   continue f() , 4  ;
-}

test/message/syntactic-tail-call-in-comma.out

-*%(basename)s:13: SyntaxError: Tail call expression is not allowed here
-  return 1, 2, 3,   continue f() , 4  ;
-                    ^^^^^^^^^^^^
-SyntaxError: Tail call expression is not allowed here

test/message/syntactic-tail-call-in-extends.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-explicit-tailcalls
-"use strict";
-
-function g() {
-  return class A extends continue f() {};
-}

test/message/syntactic-tail-call-in-extends.out

-*%(basename)s:9: SyntaxError: Tail call expression is not allowed here
-  return class A extends continue f() {};
-                         ^^^^^^^^^^^^
-SyntaxError: Tail call expression is not allowed here

test/message/syntactic-tail-call-in-for-in.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  for (var v in {a:0}) {
-    return continue f()  ;
-  }
-}

test/message/syntactic-tail-call-in-for-in.out

-*%(basename)s:14: SyntaxError: Tail call expression in for-in/of body
-    return continue f()  ;
-           ^^^^^^^^^^^^
-SyntaxError: Tail call expression in for-in/of body

test/message/syntactic-tail-call-in-for-of.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  for (var v of [1, 2, 3]) {
-    return continue f()  ;
-  }
-}

test/message/syntactic-tail-call-in-for-of.out

-*%(basename)s:14: SyntaxError: Tail call expression in for-in/of body
-    return continue f()  ;
-           ^^^^^^^^^^^^
-SyntaxError: Tail call expression in for-in/of body

test/message/syntactic-tail-call-in-logical-and.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  return   continue f()   && a ;
-}

test/message/syntactic-tail-call-in-logical-and.out

-*%(basename)s:13: SyntaxError: Tail call expression is not allowed here
-  return   continue f()   && a ;
-           ^^^^^^^^^^^^
-SyntaxError: Tail call expression is not allowed here

test/message/syntactic-tail-call-in-logical-or.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  return   continue f()   || a ;
-}

test/message/syntactic-tail-call-in-logical-or.out

-*%(basename)s:13: SyntaxError: Tail call expression is not allowed here
-  return   continue f()   || a ;
-           ^^^^^^^^^^^^
-SyntaxError: Tail call expression is not allowed here

test/message/syntactic-tail-call-in-subclass.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-explicit-tailcalls
-"use strict";
-
-function g() {
-  class A {};
-  class B extends A {
-    constructor() {
-      return continue f() ;
-    }
-  }
-}

test/message/syntactic-tail-call-in-subclass.out

-*%(basename)s:12: SyntaxError: Tail call expression is not allowed here
-      return continue f() ;
-             ^^^^^^^^^^^^
-SyntaxError: Tail call expression is not allowed here

test/message/syntactic-tail-call-in-try-catch-finally.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  try {
-    f();
-  } catch(e) {
-    return continue f()  ;
-  } finally {
-    f();
-  }
-}

test/message/syntactic-tail-call-in-try-catch-finally.out

-*%(basename)s:16: SyntaxError: Tail call expression in catch block when finally block is also present
-    return continue f()  ;
-           ^^^^^^^^^^^^
-SyntaxError: Tail call expression in catch block when finally block is also present

test/message/syntactic-tail-call-in-try-try-catch-finally.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  try {
-    try {
-      f();
-    } catch(e) {
-      return continue f()  ;
-    }
-  } finally {
-    f();
-  }
-}

test/message/syntactic-tail-call-in-try-try-catch-finally.out

-*%(basename)s:17: SyntaxError: Tail call expression in try block
-      return continue f()  ;
-             ^^^^^^^^^^^^
-SyntaxError: Tail call expression in try block

test/message/syntactic-tail-call-in-try.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  try {
-    return continue f()  ;
-  } catch(e) {
-  }
-}

test/message/syntactic-tail-call-in-try.out

-*%(basename)s:14: SyntaxError: Tail call expression in try block
-    return continue f()  ;
-           ^^^^^^^^^^^^
-SyntaxError: Tail call expression in try block

test/message/syntactic-tail-call-inside-member-expr.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  return (continue  f(1)) (2) ;
-}

test/message/syntactic-tail-call-inside-member-expr.out

-*%(basename)s:13: SyntaxError: Tail call expression is not allowed here
-  return (continue  f(1)) (2) ;
-          ^^^^^^^^^^^^^^
-SyntaxError: Tail call expression is not allowed here

test/message/syntactic-tail-call-of-eval.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-explicit-tailcalls
-
-function g() {
-  return  continue  eval  ("f()")  ;
-}

test/message/syntactic-tail-call-of-eval.out

-*%(basename)s:8: SyntaxError: Tail call of a direct eval is not allowed
-  return  continue  eval  ("f()")  ;
-                    ^^^^^^^^^^^^^
-SyntaxError: Tail call of a direct eval is not allowed

test/message/syntactic-tail-call-of-identifier.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-explicit-tailcalls
-"use strict";
-
-function g(x) {
-  return continue   x  ;
-}

test/message/syntactic-tail-call-of-identifier.out

-*%(basename)s:9: SyntaxError: Unexpected expression inside tail call
-  return continue   x  ;
-                    ^
-SyntaxError: Unexpected expression inside tail call

test/message/syntactic-tail-call-of-new.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-explicit-tailcalls
-
-function f() {
-  return 1;
-}
-
-function g() {
-  return continue new f()  ;
-}

test/message/syntactic-tail-call-of-new.out

-*%(basename)s:12: SyntaxError: Unexpected expression inside tail call
-  return continue new f()  ;
-                  ^^^^^^^
-SyntaxError: Unexpected expression inside tail call

test/message/syntactic-tail-call-sloppy.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-explicit-tailcalls
-
-function g() {
-  return  continue  f()  ;
-}

test/message/syntactic-tail-call-sloppy.out

-*%(basename)s:8: SyntaxError: Tail call expressions are not allowed in non-strict mode
-  return  continue  f()  ;
-          ^^^^^^^^^^^^^
-SyntaxError: Tail call expressions are not allowed in non-strict mode

test/message/syntactic-tail-call-without-return.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-explicit-tailcalls
-"use strict";
-
-function f() {
-  return 1;
-}
-
-function g() {
-  var x =  continue  f()  ;
-}

test/message/syntactic-tail-call-without-return.out

-*%(basename)s:13: SyntaxError: Tail call expression is not allowed here
-  var x =  continue  f()  ;
-           ^^^^^^^^^^^^^
-SyntaxError: Tail call expression is not allowed here

test/mjsunit/es8/syntactic-tail-call-simple.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-explicit-tailcalls --stack-size=100
-
-//
-// Tail calls work only in strict mode.
-//
-(function() {
-  function f(n) {
-    if (n <= 0) {
-      return "foo";
-    }
-    return f(n - 1);
-  }
-  assertThrows(()=>{ f(1e5) });
-  %OptimizeFunctionOnNextCall(f);
-  assertThrows(()=>{ f(1e5) });
-})();
-
-
-//
-// Tail call normal functions.
-//
-(function() {
-  "use strict";
-  function f(n) {
-    if (n <= 0) {
-      return "foo";
-    }
-    return continue f(n - 1);
-  }
-  assertEquals("foo", f(1e5));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals("foo", f(1e5));
-})();
-
-
-(function() {
-  "use strict";
-  function f(n) {
-    if (n <= 0) {
-      return  "foo";
-    }
-    return continue f(n - 1, 42);  // Call with arguments adaptor.
-  }
-  assertEquals("foo", f(1e5));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals("foo", f(1e5));
-})();
-
-
-(function() {
-  "use strict";
-  function f(n){
-    if (n <= 0) {
-      return "foo";
-    }
-    return continue g(n - 1);
-  }
-  function g(n){
-    if (n <= 0) {
-      return "bar";
-    }
-    return continue f(n - 1);
-  }
-  assertEquals("foo", f(1e5));
-  assertEquals("bar", f(1e5 + 1));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals("foo", f(1e5));
-  assertEquals("bar", f(1e5 + 1));
-})();
-
-
-(function() {
-  "use strict";
-  function f(n){
-    if (n <= 0) {
-      return "foo";
-    }
-    return continue g(n - 1, 42);  // Call with arguments adaptor.
-  }
-  function g(n){
-    if (n <= 0) {
-      return "bar";
-    }
-    return continue f(n - 1, 42);  // Call with arguments adaptor.
-  }
-  assertEquals("foo", f(1e5));
-  assertEquals("bar", f(1e5 + 1));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals("foo", f(1e5));
-  assertEquals("bar", f(1e5 + 1));
-})();
-
-
-//
-// Tail call bound functions.
-//
-(function() {
-  "use strict";
-  function f0(n) {
-    if (n <= 0) {
-      return "foo";
-    }
-    return continue f_bound(n - 1);
-  }
-  var f_bound = f0.bind({});
-  function f(n) {
-    return continue f_bound(n);
-  }
-  assertEquals("foo", f(1e5));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals("foo", f(1e5));
-})();
-
-
-(function() {
-  "use strict";
-  function f0(n){
-    if (n <= 0) {
-      return "foo";
-    }
-    return continue g_bound(n - 1);
-  }
-  function g0(n){
-    if (n <= 0) {
-      return "bar";
-    }
-    return continue f_bound(n - 1);
-  }
-  var f_bound = f0.bind({});
-  var g_bound = g0.bind({});
-  function f(n) {
-    return continue f_bound(n);
-  }
-  assertEquals("foo", f(1e5));
-  assertEquals("bar", f(1e5 + 1));
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals("foo", f(1e5));
-  assertEquals("bar", f(1e5 + 1));
-})();