[esnext] Remove always-disabled support for function.sent

This proposal has not moved beyoned stage 2 in two years, and has never
moved past the HARMONY_INPROGRESS state in flag-definitions.h.

It was originally added to aide in desugaring yield*, but is no longer
used for that purpose.

Bug: v8:4700, v8:7310
Change-Id: Ieca40d8e4bf565516bbe71e47b996daa70d2e835
Reviewed-on: https://chromium-review.googlesource.com/935297
Commit-Queue: Adam Klein <adamk@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51582}

src/bootstrapper.cc

@@ -4204,7 +4204,6 @@ void Bootstrapper::ExportFromRuntime(Isolate* isolate,
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_do_expressions)
 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_function_tostring)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_public_fields)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_private_fields)

src/flag-definitions.h

@@ -210,7 +210,6 @@ DEFINE_IMPLICATION(harmony_class_fields, harmony_private_fields)
 // Features that are still work in progress (behind individual flags).
 #define HARMONY_INPROGRESS(V)                                         \
   V(harmony_array_prototype_values, "harmony Array.prototype.values") \
-  V(harmony_function_sent, "harmony function.sent")                   \
   V(harmony_do_expressions, "harmony do-expressions")                 \
   V(harmony_class_fields, "harmony fields in class literals")         \
   V(harmony_static_fields, "harmony static fields in class literals") \

src/messages.h

@@ -689,8 +689,6 @@ class ErrorUtils : public AllStatic {
   T(TypedArrayTooShort,                                                        \
     "Derived TypedArray constructor created an array which was too small")     \
   T(UnexpectedEOS, "Unexpected end of input")                                  \
-  T(UnexpectedFunctionSent,                                                    \
-    "function.sent expression is not allowed outside a generator")             \
   T(UnexpectedReserved, "Unexpected reserved word")                            \
   T(UnexpectedStrictReserved, "Unexpected strict mode reserved word")          \
   T(UnexpectedSuper, "'super' keyword unexpected here")                        \

src/parsing/parser-base.h

@@ -278,7 +278,6 @@ class ParserBase {
         script_id_(script_id),
         allow_natives_(false),
         allow_harmony_do_expressions_(false),
-        allow_harmony_function_sent_(false),
         allow_harmony_public_fields_(false),
         allow_harmony_static_fields_(false),
         allow_harmony_dynamic_import_(false),
@@ -293,7 +292,6 @@ class ParserBase {
 
   ALLOW_ACCESSORS(natives);
   ALLOW_ACCESSORS(harmony_do_expressions);
-  ALLOW_ACCESSORS(harmony_function_sent);
   ALLOW_ACCESSORS(harmony_public_fields);
   ALLOW_ACCESSORS(harmony_static_fields);
   ALLOW_ACCESSORS(harmony_dynamic_import);
@@ -1553,7 +1551,6 @@ class ParserBase {
 
   bool allow_natives_;
   bool allow_harmony_do_expressions_;
-  bool allow_harmony_function_sent_;
   bool allow_harmony_public_fields_;
   bool allow_harmony_static_fields_;
   bool allow_harmony_dynamic_import_;
@@ -3561,22 +3558,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseMemberExpression(
     Consume(Token::FUNCTION);
     int function_token_position = position();
 
-    if (allow_harmony_function_sent() && peek() == Token::PERIOD) {
-      // function.sent
-      int pos = position();
-      ExpectMetaProperty(Token::SENT, "function.sent", pos, CHECK_OK);
-
-      if (!is_generator()) {
-        // TODO(neis): allow escaping into closures?
-        impl()->ReportMessageAt(scanner()->location(),
-                                MessageTemplate::kUnexpectedFunctionSent);
-        *ok = false;
-        return impl()->NullExpression();
-      }
-
-      return impl()->FunctionSentExpression(pos);
-    }
-
     FunctionKind function_kind = Check(Token::MUL)
                                      ? FunctionKind::kGeneratorFunction
                                      : FunctionKind::kNormalFunction;

src/parsing/parser.cc

@@ -318,16 +318,6 @@ Expression* Parser::NewTargetExpression(int pos) {
   return proxy;
 }
 
-Expression* Parser::FunctionSentExpression(int pos) {
-  // We desugar function.sent into %_GeneratorGetInputOrDebugPos(generator).
-  ZoneList<Expression*>* args = new (zone()) ZoneList<Expression*>(1, zone());
-  VariableProxy* generator = factory()->NewVariableProxy(
-      function_state_->scope()->generator_object_var());
-  args->Add(generator, zone());
-  return factory()->NewCallRuntime(Runtime::kInlineGeneratorGetInputOrDebugPos,
-                                   args, pos);
-}
-
 Expression* Parser::ImportMetaExpression(int pos) {
   return factory()->NewCallRuntime(
       Runtime::kInlineGetImportMetaObject,
@@ -453,7 +443,6 @@ Parser::Parser(ParseInfo* info)
                 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_function_sent(FLAG_harmony_function_sent);
   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);

src/parsing/parser.h

@@ -242,7 +242,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 #define SET_ALLOW(name) reusable_preparser_->set_allow_##name(allow_##name());
       SET_ALLOW(natives);
       SET_ALLOW(harmony_do_expressions);
-      SET_ALLOW(harmony_function_sent);
       SET_ALLOW(harmony_public_fields);
       SET_ALLOW(harmony_static_fields);
       SET_ALLOW(harmony_dynamic_import);
@@ -829,7 +828,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   Expression* NewSuperPropertyReference(int pos);
   Expression* NewSuperCallReference(int pos);
   Expression* NewTargetExpression(int pos);
-  Expression* FunctionSentExpression(int pos);
   Expression* ImportMetaExpression(int pos);
 
   Literal* ExpressionFromLiteral(Token::Value token, int pos);

src/parsing/preparser.h

@@ -1590,10 +1590,6 @@ class PreParser : public ParserBase<PreParser> {
     return PreParserExpression::NewTargetExpression();
   }
 
-  V8_INLINE PreParserExpression FunctionSentExpression(int pos) {
-    return PreParserExpression::Default();
-  }
-
   V8_INLINE PreParserExpression ImportMetaExpression(int pos) {
     return PreParserExpression::Default();
   }

src/parsing/scanner.cc

@@ -1508,7 +1508,6 @@ uc32 Scanner::ScanUnicodeEscape() {
   KEYWORD_GROUP('r')                                        \
   KEYWORD("return", Token::RETURN)                          \
   KEYWORD_GROUP('s')                                        \
-  KEYWORD("sent", Token::SENT)                              \
   KEYWORD("set", Token::SET)                                \
   KEYWORD("static", Token::STATIC)                          \
   KEYWORD("super", Token::SUPER)                            \

src/parsing/token.h

@@ -188,7 +188,6 @@ namespace internal {
   C(SET, "set", 0)                                                 \
   C(OF, "of", 0)                                                   \
   C(TARGET, "target", 0)                                           \
-  C(SENT, "sent", 0)                                               \
   C(META, "meta", 0)                                               \
   C(AS, "as", 0)                                                   \
   C(FROM, "from", 0)                                               \

test/cctest/test-parsing.cc

@@ -1115,7 +1115,6 @@ const char* ReadString(unsigned* start) {
 enum ParserFlag {
   kAllowLazy,
   kAllowNatives,
-  kAllowHarmonyFunctionSent,
   kAllowHarmonyPublicFields,
   kAllowHarmonyPrivateFields,
   kAllowHarmonyStaticFields,
@@ -1133,7 +1132,6 @@ enum ParserSyncTestResult {
 
 void SetGlobalFlags(i::EnumSet<ParserFlag> flags) {
   i::FLAG_allow_natives_syntax = flags.Contains(kAllowNatives);
-  i::FLAG_harmony_function_sent = flags.Contains(kAllowHarmonyFunctionSent);
   i::FLAG_harmony_public_fields = flags.Contains(kAllowHarmonyPublicFields);
   i::FLAG_harmony_private_fields = flags.Contains(kAllowHarmonyPrivateFields);
   i::FLAG_harmony_static_fields = flags.Contains(kAllowHarmonyStaticFields);
@@ -1146,8 +1144,6 @@ void SetGlobalFlags(i::EnumSet<ParserFlag> flags) {
 
 void SetParserFlags(i::PreParser* parser, i::EnumSet<ParserFlag> flags) {
   parser->set_allow_natives(flags.Contains(kAllowNatives));
-  parser->set_allow_harmony_function_sent(
-      flags.Contains(kAllowHarmonyFunctionSent));
   parser->set_allow_harmony_public_fields(
       flags.Contains(kAllowHarmonyPublicFields));
   parser->set_allow_harmony_private_fields(
@@ -8443,26 +8439,6 @@ TEST(EscapeSequenceErrors) {
   RunParserSyncTest(context_data, error_data, kError);
 }
 
-
-TEST(FunctionSentErrors) {
-  // clang-format off
-  const char* context_data[][2] = {
-    { "'use strict'", "" },
-    { "", "" },
-    { nullptr, nullptr }
-  };
-  const char* error_data[] = {
-    "var x = function.sent",
-    "function* g() { yield function.s\\u0065nt; }",
-    nullptr
-  };
-  // clang-format on
-
-  static const ParserFlag always_flags[] = {kAllowHarmonyFunctionSent};
-  RunParserSyncTest(context_data, error_data, kError, always_flags,
-                    arraysize(always_flags));
-}
-
 TEST(NewTargetErrors) {
   // clang-format off
   const char* context_data[][2] = {

test/js-perf-test/Generators/generators.js

@@ -67,7 +67,7 @@ function Loop() {
 // ----------------------------------------------------------------------------
 
 function* multiples(x) {
-  let skip = function.sent || 0;
+  let skip = 2;
   let next = 0;
   while (true) {
     if (skip === 0) {

test/js-perf-test/JSTests.json

@@ -56,7 +56,6 @@
       "path": ["Generators"],
       "main": "run.js",
       "resources": ["generators.js"],
-      "flags": ["--harmony-function-sent"],
       "results_regexp": "^Generators\\-Generators\\(Score\\): (.+)$"
     },
     {

test/message/fail/function-sent-escaped.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-function-sent
-
-function* f() {
-  return function.s\u0065nt;
-}
-for (var i of f()) print(i);

test/message/fail/function-sent-escaped.out

-*%(basename)s:8: SyntaxError: 'function.sent' must not contain escaped characters
-  return function.s\u0065nt;
-         ^^^^^^^^^^^^^^^^^^
-SyntaxError: 'function.sent' must not contain escaped characters

test/mjsunit/harmony/function-sent.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-function-sent
-
-
-{
-  function* g() { return function.sent }
-  assertEquals({value: 42, done: true}, g().next(42));
-}
-
-
-{
-  function* g() {
-    try {
-      yield function.sent;
-    } finally {
-      yield function.sent;
-      return function.sent;
-    }
-  }
-
-  {
-    let x = g();
-    assertEquals({value: 1, done: false}, x.next(1));
-    assertEquals({value: 2, done: false}, x.next(2));
-    assertEquals({value: 3, done: true}, x.next(3));
-  }
-
-  {
-    let x = g();
-    assertEquals({value: 1, done: false}, x.next(1));
-    assertEquals({value: 2, done: false}, x.throw(2));
-    assertEquals({value: 3, done: true}, x.next(3));
-  }
-
-  {
-    let x = g();
-    assertEquals({value: 1, done: false}, x.next(1));
-    assertEquals({value: 2, done: false}, x.return(2));
-    assertEquals({value: 3, done: true}, x.next(3));
-  }
-}
-
-
-{
-  function* inner() {
-    try {
-      yield function.sent;
-    } finally {
-      return 23;
-    }
-  }
-
-  function* g() {
-    yield function.sent;
-    yield* inner();
-    return function.sent;
-  }
-
-  {
-    let x = g();
-    assertEquals({value: 1, done: false}, x.next(1));
-    assertEquals({value: undefined, done: false}, x.next(2));
-    assertEquals({value: 3, done: true}, x.next(3));
-  }
-
-  {
-    let x = g();
-    assertEquals({value: 1, done: false}, x.next(1));
-    assertEquals({value: undefined, done: false}, x.next(2));
-    assertEquals({value: 42, done: true}, x.throw(42));
-  }
-
-  {
-    let x = g();
-    assertEquals({value: 1, done: false}, x.next(1));
-    assertEquals({value: undefined, done: false}, x.next(2));
-    assertEquals({value: 23, done: true}, x.return(42));
-  }
-}
-
-
-assertThrows("function f() { return function.sent }", SyntaxError);
-assertThrows("() => { return function.sent }", SyntaxError);
-assertThrows("() => { function.sent }", SyntaxError);
-assertThrows("() => function.sent", SyntaxError);
-assertThrows("({*f() { function.sent }})", SyntaxError);
-assertDoesNotThrow("({*f() { return function.sent }})");