[parser] Provide better error when incorrectly using await

Before we try to do ASI and fail with a generic error, we special case
for the await token in the failure case.

Bug: v8:6572, v8:6513
Change-Id: Ia050c98b5a5b20bc326f429a367635b8553e4112
Reviewed-on: https://chromium-review.googlesource.com/582210Reviewed-by: Daniel Ehrenberg <littledan@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46885}

src/messages.h

@@ -270,6 +270,7 @@ class ErrorUtils : public AllStatic {
     "ArrayBuffer subclass returned this from species constructor")             \
   T(ArrayFunctionsOnFrozen, "Cannot modify frozen array elements")             \
   T(ArrayFunctionsOnSealed, "Cannot add/remove sealed array elements")         \
+  T(AwaitNotInAsyncFunction, "await is only valid in async function")          \
   T(AtomicsWaitNotAllowed, "Atomics.wait cannot be called in this context")    \
   T(CalledNonCallable, "% is not a function")                                  \
   T(CalledOnNonObject, "% called on non-object")                               \

src/parsing/parser-base.h

@@ -698,7 +698,24 @@ class ParserBase {
         tok == Token::EOS) {
       return;
     }
-    Expect(Token::SEMICOLON, ok);
+
+    Token::Value current = scanner()->current_token();
+    Scanner::Location current_location = scanner()->location();
+    Token::Value next = Next();
+
+    if (next == Token::SEMICOLON) {
+      return;
+    }
+
+    *ok = false;
+    if (current == Token::AWAIT) {
+      DCHECK(!is_async_function());
+      ReportMessageAt(current_location,
+                      MessageTemplate::kAwaitNotInAsyncFunction, kSyntaxError);
+      return;
+    }
+
+    ReportUnexpectedToken(next);
   }
 
   // Dummy functions, just useful as arguments to CHECK_OK_CUSTOM.

test/cctest/interpreter/bytecode_expectations/AsyncGenerators.golden

@@ -419,7 +419,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(19),
                 B(LdaConstant), U8(15),
                 B(Star), R(20),
@@ -720,7 +720,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(16),
                 B(LdaConstant), U8(21),
                 B(Star), R(17),
@@ -784,7 +784,7 @@ bytecodes: [
                 B(JumpIfToBooleanFalse), U8(4),
                 B(Jump), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(7), U8(1),
-                B(Wide), B(LdaSmi), I16(145),
+                B(Wide), B(LdaSmi), I16(146),
                 B(Star), R(16),
                 B(LdaConstant), U8(21),
                 B(Star), R(17),

test/cctest/interpreter/bytecode_expectations/ForAwaitOf.golden

@@ -152,7 +152,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(20),
                 B(LdaConstant), U8(13),
                 B(Star), R(21),
@@ -456,7 +456,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(20),
                 B(LdaConstant), U8(13),
                 B(Star), R(21),
@@ -784,7 +784,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(20),
                 B(LdaConstant), U8(13),
                 B(Star), R(21),
@@ -1039,7 +1039,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(16),
                 B(LdaConstant), U8(10),
                 B(Star), R(17),

test/cctest/interpreter/bytecode_expectations/ForOf.golden

@@ -85,7 +85,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(11),
                 B(LdaConstant), U8(8),
                 B(Star), R(12),
@@ -225,7 +225,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(12),
                 B(LdaConstant), U8(8),
                 B(Star), R(13),
@@ -377,7 +377,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(11),
                 B(LdaConstant), U8(8),
                 B(Star), R(12),
@@ -519,7 +519,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(10),
                 B(LdaConstant), U8(10),
                 B(Star), R(11),

test/cctest/interpreter/bytecode_expectations/ForOfLoop.golden

@@ -91,7 +91,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(13),
                 B(LdaConstant), U8(7),
                 B(Star), R(14),
@@ -268,7 +268,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(12),
                 B(LdaConstant), U8(11),
                 B(Star), R(13),
@@ -423,7 +423,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(11),
                 B(LdaConstant), U8(9),
                 B(Star), R(12),
@@ -529,7 +529,7 @@ bytecodes: [
                 B(JumpIfUndefined), U8(6),
                 B(Ldar), R(6),
                 B(JumpIfNotNull), U8(16),
-                B(LdaSmi), I8(62),
+                B(LdaSmi), I8(63),
                 B(Star), R(17),
                 B(LdaConstant), U8(4),
                 B(Star), R(18),
@@ -584,7 +584,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(16),
                 B(LdaConstant), U8(9),
                 B(Star), R(17),
@@ -763,7 +763,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(17),
                 B(LdaConstant), U8(10),
                 B(Star), R(18),
@@ -969,7 +969,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(16),
                 B(LdaConstant), U8(14),
                 B(Star), R(17),
@@ -1135,7 +1135,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(20),
                 B(LdaConstant), U8(7),
                 B(Star), R(21),
@@ -1392,7 +1392,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(21),
                 B(LdaConstant), U8(9),
                 B(Star), R(22),

test/cctest/interpreter/bytecode_expectations/Generators.golden

@@ -272,7 +272,7 @@ bytecodes: [
                 B(TestTypeOf), U8(5),
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(18),
-                B(Wide), B(LdaSmi), I16(131),
+                B(Wide), B(LdaSmi), I16(132),
                 B(Star), R(15),
                 B(LdaConstant), U8(15),
                 B(Star), R(16),

test/cctest/interpreter/bytecode_expectations/StandardForLoop.golden

@@ -231,7 +231,7 @@ bytecodes: [
                 B(JumpIfUndefined), U8(6),
                 B(Ldar), R(3),
                 B(JumpIfNotNull), U8(16),
-                B(LdaSmi), I8(62),
+                B(LdaSmi), I8(63),
                 B(Star), R(4),
                 B(LdaConstant), U8(1),
                 B(Star), R(5),

test/message/await-non-async.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.
+
+function f() { await Promise.resolve(); }

test/message/await-non-async.out

+*%(basename)s:5: SyntaxError: await is only valid in async function
+function f() { await Promise.resolve(); }
+               ^^^^^
+SyntaxError: await is only valid in async function

test/mjsunit/es8/async-await-basic.js

@@ -562,3 +562,42 @@ assertDoesNotThrow(gaga);
   %RunMicrotasks();
   assertEquals(["a", "b", "c"], log);
 }
+
+{
+  function f1() {
+    var x;
+    with ({get await() { return [42] }}) {
+      x = await
+      [0];
+    };
+    return x;
+  }
+
+  assertEquals(42, f1());
+  async function f2() {
+    var x;
+    with ({get await() { return [42] }}) {
+      x = await
+      [0];
+    };
+    return x;
+  }
+
+  var ans;
+  f2().then(x => ans = x).catch(e => ans = e);
+  %RunMicrotasks();
+  assertEquals([0], ans);
+}
+
+{
+  function f1() {
+    var x, y;
+    with ({get await() { return [42] }}) {
+      x = await
+      y = 1
+    };
+    return y;
+  }
+
+  assertEquals(1, f1());
+}