Preparse inner functions (new try)

src/parsing/preparser.cc

Index: src/parsing/preparser.cc
diff --git a/src/parsing/preparser.cc b/src/parsing/preparser.cc
index 37beecf5a40aedfc577c3b2432a7085081e26f58..0eea0e66181149e75cae1c52cb3622ef1326ea03 100644
--- a/src/parsing/preparser.cc
+++ b/src/parsing/preparser.cc
@@ -38,8 +38,10 @@ namespace internal {
 #define CHECK_OK CHECK_OK_VALUE(Statement::Default())
 #define CHECK_OK_VOID CHECK_OK_VALUE(this->Void())
 
-PreParserIdentifier PreParser::GetSymbol() const {
-  switch (scanner()->current_token()) {
+namespace {
+
+PreParserIdentifier GetSymbolHelper(Scanner* scanner) {
+  switch (scanner->current_token()) {
     case Token::ENUM:
       return PreParserIdentifier::Enum();
     case Token::AWAIT:
@@ -55,34 +57,46 @@ PreParserIdentifier PreParser::GetSymbol() const {
     case Token::ASYNC:
       return PreParserIdentifier::Async();
     default:
-      if (scanner()->UnescapedLiteralMatches("eval", 4))
+      if (scanner->UnescapedLiteralMatches("eval", 4))
         return PreParserIdentifier::Eval();
-      if (scanner()->UnescapedLiteralMatches("arguments", 9))
+      if (scanner->UnescapedLiteralMatches("arguments", 9))
         return PreParserIdentifier::Arguments();
-      if (scanner()->UnescapedLiteralMatches("undefined", 9))
+      if (scanner->UnescapedLiteralMatches("undefined", 9))
         return PreParserIdentifier::Undefined();
-      if (scanner()->LiteralMatches("prototype", 9))
+      if (scanner->LiteralMatches("prototype", 9))
         return PreParserIdentifier::Prototype();
-      if (scanner()->LiteralMatches("constructor", 11))
+      if (scanner->LiteralMatches("constructor", 11))
         return PreParserIdentifier::Constructor();
       return PreParserIdentifier::Default();
   }
 }
 
+}  // unnamed namespace
+
+PreParserIdentifier PreParser::GetSymbol() const {
+  PreParserIdentifier symbol = GetSymbolHelper(scanner());
+  if (track_unresolved_variables_) {
+    const AstRawString* result = scanner()->CurrentSymbol(ast_value_factory());
+    DCHECK_NOT_NULL(result);
+    symbol.string_ = result;
+  }
+  return symbol;
+}
+
 PreParser::PreParseResult PreParser::PreParseLazyFunction(
-    LanguageMode language_mode, FunctionKind kind, bool has_simple_parameters,
-    bool parsing_module, ParserRecorder* log, bool may_abort, int* use_counts) {
+    FunctionKind kind, DeclarationScope* function_scope, bool parsing_module,
+    ParserRecorder* log, bool is_inner_function, bool may_abort,
+    int* use_counts) {
   parsing_module_ = parsing_module;
   log_ = log;
   use_counts_ = use_counts;
-  // Lazy functions always have trivial outer scopes (no with/catch scopes).
+  DCHECK(!track_unresolved_variables_);
+  track_unresolved_variables_ = is_inner_function;
+
+  // The caller passes the function_scope which is not yet inserted into the
+  // scope_state_. All scopes above the function_scope are ignored by the
+  // PreParser.
   DCHECK_NULL(scope_state_);
-  DeclarationScope* top_scope = NewScriptScope();
-  FunctionState top_state(&function_state_, &scope_state_, top_scope,
-                          kNormalFunction);
-  scope()->SetLanguageMode(language_mode);
-  DeclarationScope* function_scope = NewFunctionScope(kind);
-  if (!has_simple_parameters) function_scope->SetHasNonSimpleParameters();
   FunctionState function_state(&function_state_, &scope_state_, function_scope,
                                kind);
   DCHECK_EQ(Token::LBRACE, scanner()->current_token());
@@ -90,6 +104,7 @@ PreParser::PreParseResult PreParser::PreParseLazyFunction(
   int start_position = peek_position();
   LazyParsingResult result = ParseLazyFunctionLiteralBody(may_abort, &ok);
   use_counts_ = nullptr;
+  track_unresolved_variables_ = false;
   if (result == kLazyParsingAborted) {
     return kPreParseAbort;
   } else if (stack_overflow()) {
@@ -340,6 +355,21 @@ void PreParser::ParseAsyncArrowSingleExpressionBody(PreParserStatementList body,
   body->Add(PreParserStatement::ExpressionStatement(return_value), zone());
 }
 
+PreParserExpression PreParser::ExpressionFromIdentifier(
+    PreParserIdentifier name, int start_position, int end_position,
+    InferName infer) {
+  if (track_unresolved_variables_) {
+    AstNodeFactory factory(ast_value_factory());
+    // Setting the Zone is necessary because zone_ might be the temp Zone, and
+    // AstValueFactory doesn't know about it.
+    factory.set_zone(zone());
+    DCHECK_NOT_NULL(name.string_);
+    scope()->NewUnresolved(&factory, name.string_, start_position, end_position,
+                           NORMAL_VARIABLE);
+  }
+  return PreParserExpression::FromIdentifier(name);
+}
+
 #undef CHECK_OK
 #undef CHECK_OK_CUSTOM