[parser] Lift template literal invalid escape restriction

test/cctest/test-parsing.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1268 matching lines @@
 
 enum ParserFlag {
   kAllowLazy,
   kAllowNatives,
   kAllowHarmonyFunctionSent,
   kAllowHarmonyRestrictiveGenerators,
   kAllowHarmonyTrailingCommas,
   kAllowHarmonyClassFields,
   kAllowHarmonyObjectRestSpread,
   kAllowHarmonyDynamicImport,
+  kAllowHarmonyTemplateEscapes,
 };
 
 enum ParserSyncTestResult {
   kSuccessOrError,
   kSuccess,
   kError
 };
 
 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_restrictive_generators =
       flags.Contains(kAllowHarmonyRestrictiveGenerators);
   i::FLAG_harmony_trailing_commas = flags.Contains(kAllowHarmonyTrailingCommas);
   i::FLAG_harmony_class_fields = flags.Contains(kAllowHarmonyClassFields);
   i::FLAG_harmony_object_rest_spread =
       flags.Contains(kAllowHarmonyObjectRestSpread);
   i::FLAG_harmony_dynamic_import = flags.Contains(kAllowHarmonyDynamicImport);
+  i::FLAG_harmony_template_escapes =
+      flags.Contains(kAllowHarmonyTemplateEscapes);
 }
 
 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_restrictive_generators(
       flags.Contains(kAllowHarmonyRestrictiveGenerators));
   parser->set_allow_harmony_trailing_commas(
       flags.Contains(kAllowHarmonyTrailingCommas));
   parser->set_allow_harmony_class_fields(
       flags.Contains(kAllowHarmonyClassFields));
   parser->set_allow_harmony_object_rest_spread(
       flags.Contains(kAllowHarmonyObjectRestSpread));
   parser->set_allow_harmony_dynamic_import(
       flags.Contains(kAllowHarmonyDynamicImport));
+  parser->set_allow_harmony_template_escapes(
+      flags.Contains(kAllowHarmonyTemplateEscapes));
 }
 
 void TestParserSyncWithFlags(i::Handle<i::String> source,
                              i::EnumSet<ParserFlag> flags,
                              ParserSyncTestResult result,
                              bool is_module = false, bool test_preparser = true,
                              bool ignore_error_msg = false) {
   i::Isolate* isolate = CcTest::i_isolate();
   i::Factory* factory = isolate->factory();
 
@@ skipping 5407 matching lines @@
     "{ ...y, b: 1}",
     "{ ...1}",
     "{ ...null}",
     "{ ...undefined}",
     "{ ...1 in {}}",
     "{ ...[]}",
     "{ ...async function() { }}",
     "{ ...async () => { }}",
     "{ ...new Foo()}",
     NULL};
+  // clang-format on
 
   static const ParserFlag flags[] = {kAllowHarmonyObjectRestSpread};
   RunParserSyncTest(context_data, data, kSuccess, NULL, 0, flags,
                     arraysize(flags));
 }
 
 TEST(ObjectSpreadNegativeTests) {
   const char* context_data[][2] = {{"x = ", ""},
                                    {"'use strict'; x = ", ""},
                                    {NULL, NULL}};
 
   // clang-format off
   const char* data[] = {
     "{ ...var z = y}",
     "{ ...var}",
     "{ ...foo bar}",
     NULL};
 
   static const ParserFlag flags[] = {kAllowHarmonyObjectRestSpread};
   RunParserSyncTest(context_data, data, kError, NULL, 0, flags,
                     arraysize(flags));
 }
 
+TEST(TemplateEscapesPositiveTests) {
+  // clang-format off
+  const char* context_data[][2] = {
+    {"", ""},
+    {"'use strict';", ""},
+    {NULL, NULL}};
+
+  // clang-format off
+  const char* data[] = {
+    "tag`\\01`",
+    "tag`\\01${0}right`",
+    "tag`left${0}\\01`",
+    "tag`left${0}\\01${1}right`",
+    "tag`\\1`",
+    "tag`\\1${0}right`",
+    "tag`left${0}\\1`",
+    "tag`left${0}\\1${1}right`",
+    "tag`\\xg`",
+    "tag`\\xg${0}right`",
+    "tag`left${0}\\xg`",
+    "tag`left${0}\\xg${1}right`",
+    "tag`\\xAg`",
+    "tag`\\xAg${0}right`",
+    "tag`left${0}\\xAg`",
+    "tag`left${0}\\xAg${1}right`",
+    "tag`\\u0`",
+    "tag`\\u0${0}right`",
+    "tag`left${0}\\u0`",
+    "tag`left${0}\\u0${1}right`",
+    "tag`\\u0g`",
+    "tag`\\u0g${0}right`",
+    "tag`left${0}\\u0g`",
+    "tag`left${0}\\u0g${1}right`",
+    "tag`\\u00g`",
+    "tag`\\u00g${0}right`",
+    "tag`left${0}\\u00g`",
+    "tag`left${0}\\u00g${1}right`",
+    "tag`\\u000g`",
+    "tag`\\u000g${0}right`",
+    "tag`left${0}\\u000g`",
+    "tag`left${0}\\u000g${1}right`",
+    "tag`\\u{}`",
+    "tag`\\u{}${0}right`",
+    "tag`left${0}\\u{}`",
+    "tag`left${0}\\u{}${1}right`",
+    "tag`\\u{-0}`",
+    "tag`\\u{-0}${0}right`",
+    "tag`left${0}\\u{-0}`",
+    "tag`left${0}\\u{-0}${1}right`",
+    "tag`\\u{g}`",
+    "tag`\\u{g}${0}right`",
+    "tag`left${0}\\u{g}`",
+    "tag`left${0}\\u{g}${1}right`",
+    "tag`\\u{0`",
+    "tag`\\u{0${0}right`",
+    "tag`left${0}\\u{0`",
+    "tag`left${0}\\u{0${1}right`",
+    "tag`\\u{\\u{0}`",
+    "tag`\\u{\\u{0}${0}right`",
+    "tag`left${0}\\u{\\u{0}`",
+    "tag`left${0}\\u{\\u{0}${1}right`",
+    "tag`\\u{110000}`",
+    "tag`\\u{110000}${0}right`",
+    "tag`left${0}\\u{110000}`",
+    "tag`left${0}\\u{110000}${1}right`",
+    NULL};
+  // clang-format on
+
+  static const ParserFlag flags[] = {kAllowHarmonyTemplateEscapes};
+  RunParserSyncTest(context_data, data, kSuccess, NULL, 0, flags,

[vogelheim, 2017/02/13 17:36:06]

If I read this correctly, this tests the behaviour with the new flag.

Obviously, we'd also want to test whether these changes might have disturbed the
current implementation, and make sure the current behaviour is unchanged.

[bakkot1, 2017/02/13 20:22:24]

I was figuring the existing tests would suffice for that, but I'm happy to add
more if you think it's warranted.

[vogelheim, 2017/02/17 16:33:53]

Well, I was thinking more about also running the new test cases when the new
flag is off, making sure they still through the same error as today.

[bakkot1, 2017/02/17 20:42:18]

Done.

+                    arraysize(flags));
+}
+
+TEST(TemplateEscapesNegativeTests) {
+  // clang-format off
+  const char* context_data[][2] = {
+    {"", ""},
+    {"'use strict';", ""},
+    {NULL, NULL}};
+
+  // clang-format off
+  const char* data[] = {
+    "`\\01`",
+    "`\\01${0}right`",
+    "`left${0}\\01`",
+    "`left${0}\\01${1}right`",
+    "`\\1`",
+    "`\\1${0}right`",
+    "`left${0}\\1`",
+    "`left${0}\\1${1}right`",
+    "`\\xg`",
+    "`\\xg${0}right`",
+    "`left${0}\\xg`",
+    "`left${0}\\xg${1}right`",
+    "`\\xAg`",
+    "`\\xAg${0}right`",
+    "`left${0}\\xAg`",
+    "`left${0}\\xAg${1}right`",
+    "`\\u0`",
+    "`\\u0${0}right`",
+    "`left${0}\\u0`",
+    "`left${0}\\u0${1}right`",
+    "`\\u0g`",
+    "`\\u0g${0}right`",
+    "`left${0}\\u0g`",
+    "`left${0}\\u0g${1}right`",
+    "`\\u00g`",
+    "`\\u00g${0}right`",
+    "`left${0}\\u00g`",
+    "`left${0}\\u00g${1}right`",
+    "`\\u000g`",
+    "`\\u000g${0}right`",
+    "`left${0}\\u000g`",
+    "`left${0}\\u000g${1}right`",
+    "`\\u{}`",
+    "`\\u{}${0}right`",
+    "`left${0}\\u{}`",
+    "`left${0}\\u{}${1}right`",
+    "`\\u{-0}`",
+    "`\\u{-0}${0}right`",
+    "`left${0}\\u{-0}`",
+    "`left${0}\\u{-0}${1}right`",
+    "`\\u{g}`",
+    "`\\u{g}${0}right`",
+    "`left${0}\\u{g}`",
+    "`left${0}\\u{g}${1}right`",
+    "`\\u{0`",
+    "`\\u{0${0}right`",
+    "`left${0}\\u{0`",
+    "`left${0}\\u{0${1}right`",
+    "`\\u{\\u{0}`",
+    "`\\u{\\u{0}${0}right`",
+    "`left${0}\\u{\\u{0}`",
+    "`left${0}\\u{\\u{0}${1}right`",
+    "`\\u{110000}`",
+    "`\\u{110000}${0}right`",
+    "`left${0}\\u{110000}`",
+    "`left${0}\\u{110000}${1}right`",
+    NULL};
+  // clang-format on
+
+  static const ParserFlag flags[] = {kAllowHarmonyTemplateEscapes};
+  RunParserSyncTest(context_data, data, kError, NULL, 0, flags,
+                    arraysize(flags));
+}
+
 TEST(DestructuringPositiveTests) {
   const char* context_data[][2] = {{"'use strict'; let ", " = {};"},
                                    {"var ", " = {};"},
                                    {"'use strict'; const ", " = {};"},
                                    {"function f(", ") {}"},
                                    {"function f(argument1, ", ") {}"},
                                    {"var f = (", ") => {};"},
                                    {"var f = (argument1,", ") => {};"},
                                    {"try {} catch(", ") {}"},
                                    {NULL, NULL}};
@@ skipping 2745 matching lines @@
         eager_info.literal()->scope()->inner_scope()->inner_scope();
     DCHECK_NOT_NULL(scope);
     DCHECK_NULL(scope->sibling());
     DCHECK(scope->is_function_scope());
 
     size_t index = 0;
     i::ScopeTestHelper::CompareScopeToData(
         scope, lazy_info.preparsed_scope_data(), index);
   }
 }