[parser] Lift template literal invalid escape restriction

test/cctest/test-parsing.cc

Index: test/cctest/test-parsing.cc
diff --git a/test/cctest/test-parsing.cc b/test/cctest/test-parsing.cc
index a239dfa81bcd446aceda6a81e801df9c2c7d0530..f2e90ae259902619df96b46725597579bbd395c0 100644
--- a/test/cctest/test-parsing.cc
+++ b/test/cctest/test-parsing.cc
@@ -1263,6 +1263,7 @@ enum ParserFlag {
   kAllowHarmonyObjectRestSpread,
   kAllowHarmonyDynamicImport,
   kAllowHarmonyAsyncIteration,
+  kAllowHarmonyTemplateEscapes,
 };
 
 enum ParserSyncTestResult {
@@ -1282,6 +1283,8 @@ void SetGlobalFlags(i::EnumSet<ParserFlag> flags) {
       flags.Contains(kAllowHarmonyObjectRestSpread);
   i::FLAG_harmony_dynamic_import = flags.Contains(kAllowHarmonyDynamicImport);
   i::FLAG_harmony_async_iteration = flags.Contains(kAllowHarmonyAsyncIteration);
+  i::FLAG_harmony_template_escapes =
+      flags.Contains(kAllowHarmonyTemplateEscapes);
 }
 
 void SetParserFlags(i::PreParser* parser, i::EnumSet<ParserFlag> flags) {
@@ -1300,6 +1303,8 @@ void SetParserFlags(i::PreParser* parser, i::EnumSet<ParserFlag> flags) {
       flags.Contains(kAllowHarmonyDynamicImport));
   parser->set_allow_harmony_async_iteration(
       flags.Contains(kAllowHarmonyAsyncIteration));
+  parser->set_allow_harmony_template_escapes(
+      flags.Contains(kAllowHarmonyTemplateEscapes));
 }
 
 void TestParserSyncWithFlags(i::Handle<i::String> source,
@@ -7067,6 +7072,7 @@ TEST(ObjectSpreadPositiveTests) {
     "{ ...async () => { }}",
     "{ ...new Foo()}",
     NULL};
+  // clang-format on
 
   static const ParserFlag flags[] = {kAllowHarmonyObjectRestSpread};
   RunParserSyncTest(context_data, data, kSuccess, NULL, 0, flags,
@@ -7090,6 +7096,161 @@ TEST(ObjectSpreadNegativeTests) {
                     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
+
+  // No error with flag
+  static const ParserFlag flags[] = {kAllowHarmonyTemplateEscapes};
+  RunParserSyncTest(context_data, data, kSuccess, NULL, 0, flags,
+                    arraysize(flags));
+
+  // Still an error without flag
+  RunParserSyncTest(context_data, data, kError);
+}
+
+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`",
+    "`\\1``\\2`",
+    NULL};
+  // clang-format on
+
+  // Error with flag
+  static const ParserFlag flags[] = {kAllowHarmonyTemplateEscapes};
+  RunParserSyncTest(context_data, data, kError, NULL, 0, flags,
+                    arraysize(flags));
+
+  // Still an error without flag
+  RunParserSyncTest(context_data, data, kError);
+}
+
 TEST(DestructuringPositiveTests) {
   const char* context_data[][2] = {{"'use strict'; let ", " = {};"},
                                    {"var ", " = {};"},