[parser] Skipping inner funcs: Fix variable name debug mode check.

Apparently it can happen that the variable to which we're restoring to has a
two-byte name corresponding to the one-byte name we expect. Modify the debug-mode
name check to allow this.

BUG=v8:7428

Change-Id: I94c56a4b2de3c58b50246fecaead332b0f9679b4
Reviewed-on: https://chromium-review.googlesource.com/911801Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51304}

src/parsing/preparse-data-format.h

@@ -14,7 +14,7 @@ struct PreparseDataConstants {
  public:
   // Layout and constants of the preparse data exchange format.
   static const unsigned kMagicNumber = 0xBadDead;
-  static const unsigned kCurrentVersion = 17;
+  static const unsigned kCurrentVersion = 18;
 
   static const int kMagicOffset = 0;
   static const int kVersionOffset = 1;

src/parsing/preparsed-scope-data.cc

@@ -396,6 +396,7 @@ void ProducedPreParsedScopeData::SaveDataForVariable(Variable* var) {
   // Store the variable name in debug mode; this way we can check that we
   // restore data to the correct variable.
   const AstRawString* name = var->raw_name();
+  byte_data_->WriteUint8(name->is_one_byte());
   byte_data_->WriteUint32(name->length());
   for (int i = 0; i < name->length(); ++i) {
     byte_data_->WriteUint8(name->raw_data()[i]);
@@ -605,9 +606,20 @@ void ConsumedPreParsedScopeData::RestoreData(Scope* scope) {
 void ConsumedPreParsedScopeData::RestoreDataForVariable(Variable* var) {
 #ifdef DEBUG
   const AstRawString* name = var->raw_name();
+  bool data_one_byte = scope_data_->ReadUint8();
+  DCHECK_IMPLIES(name->is_one_byte(), data_one_byte);
   DCHECK_EQ(scope_data_->ReadUint32(), static_cast<uint32_t>(name->length()));
-  for (int i = 0; i < name->length(); ++i) {
-    DCHECK_EQ(scope_data_->ReadUint8(), name->raw_data()[i]);
+  if (!name->is_one_byte() && data_one_byte) {
+    // It's possible that "name" is a two-byte representation of the string
+    // stored in the data.
+    for (int i = 0; i < 2 * name->length(); i += 2) {
+      DCHECK_EQ(scope_data_->ReadUint8(), name->raw_data()[i]);
+      DCHECK_EQ(0, name->raw_data()[i + 1]);
+    }
+  } else {
+    for (int i = 0; i < name->length(); ++i) {
+      DCHECK_EQ(scope_data_->ReadUint8(), name->raw_data()[i]);
+    }
   }
 #endif
   uint8_t variable_data = scope_data_->ReadQuarter();

test/mjsunit/skipping-inner-functions.js

@@ -365,3 +365,15 @@ TestSkippableFunctionInForOfHeaderAndBody();
   function lazy(p = (function() {}, class {}, function() {}, class { method1() { } })) { }
   lazy();
 })();
+
+(function TestOneByteTwoByteMismatch() {
+  // Regression test for
+  // https://bugs.chromium.org/p/v8/issues/detail?id=7428
+
+  let name = 'weird_string\u2653'.slice(0, 12);
+  let o = {};
+  o[name] = null;
+  var x;
+  eval('x = function weird_string() { function skip() {} };');
+  x();
+})();