[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 5a7809c5862a0aefde1ab7ae76360306b63fc550..312268f6a85168c96eb97ae1ef009f4f9eeb9085 100644
--- a/test/cctest/test-parsing.cc
+++ b/test/cctest/test-parsing.cc
@@ -1286,6 +1286,7 @@ enum ParserFlag {
   kAllowHarmonyClassFields,
   kAllowHarmonyObjectRestSpread,
   kAllowHarmonyDynamicImport,
+  kAllowHarmonyTemplateEscapes,
 };
 
 enum ParserSyncTestResult {
@@ -1304,6 +1305,8 @@ void SetGlobalFlags(i::EnumSet<ParserFlag> flags) {
   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) {
@@ -1320,6 +1323,8 @@ void SetParserFlags(i::PreParser* parser, i::EnumSet<ParserFlag> flags) {
       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,
@@ -6747,6 +6752,7 @@ TEST(ObjectSpreadPositiveTests) {
     "{ ...async () => { }}",
     "{ ...new Foo()}",
     NULL};
+  // clang-format on
 
   static const ParserFlag flags[] = {kAllowHarmonyObjectRestSpread};
   RunParserSyncTest(context_data, data, kSuccess, NULL, 0, flags,
@@ -6770,6 +6776,152 @@ 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
+
+  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 ", " = {};"},