Eagerly declare eval scopes, even for sloppy scopes

src/parser.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/api.h"
 #include "src/ast.h"
 #include "src/bailout-reason.h"
 #include "src/base/platform/platform.h"
@@ skipping 943 matching lines @@
 }
 
 
 FunctionLiteral* Parser::DoParseProgram(ParseInfo* info) {
   // Note that this function can be called from the main thread or from a
   // background thread. We should not access anything Isolate / heap dependent
   // via ParseInfo, and also not pass it forward.
   DCHECK(scope_ == NULL);
   DCHECK(target_stack_ == NULL);
 
+  Mode parsing_mode = FLAG_lazy && allow_lazy() ? PARSE_LAZILY : PARSE_EAGERLY;
+  if (allow_natives() || extension_ != NULL) parsing_mode = PARSE_EAGERLY;
+
   FunctionLiteral* result = NULL;
   {
     Scope* scope = NewScope(scope_, SCRIPT_SCOPE);
     info->set_script_scope(scope);
     if (!info->context().is_null() && !info->context()->IsNativeContext()) {
       scope = Scope::DeserializeScopeChain(info->isolate(), zone(),
                                            *info->context(), scope);
       // The Scope is backed up by ScopeInfo (which is in the V8 heap); this
       // means the Parser cannot operate independent of the V8 heap. Tell the
       // string table to internalize strings and values right after they're
       // created. This kind of parsing can only be done in the main thread.
       DCHECK(parsing_on_main_thread_);
       ast_value_factory()->Internalize(info->isolate());
     }
     original_scope_ = scope;
     if (info->is_eval()) {
       if (!scope->is_script_scope() || is_strict(info->language_mode())) {
-        scope = NewScope(scope, EVAL_SCOPE);
+        parsing_mode = PARSE_EAGERLY;
       }
+      scope = NewScope(scope, EVAL_SCOPE);
     } else if (info->is_module()) {
       scope = NewScope(scope, MODULE_SCOPE);
     }
 
     scope->set_start_position(0);
 
-    // Compute the parsing mode.
-    Mode mode = (FLAG_lazy && allow_lazy()) ? PARSE_LAZILY : PARSE_EAGERLY;
-    if (allow_natives() || extension_ != NULL || scope->is_eval_scope()) {
-      mode = PARSE_EAGERLY;
-    }
-    ParsingModeScope parsing_mode(this, mode);
-
-    // Enters 'scope'.
+    // Enter 'scope' with the given parsing mode.
+    ParsingModeScope parsing_mode_scope(this, parsing_mode);
     AstNodeFactory function_factory(ast_value_factory());
     FunctionState function_state(&function_state_, &scope_, scope,
                                  kNormalFunction, &function_factory);
 
     scope_->SetLanguageMode(info->language_mode());
     ZoneList<Statement*>* body = new(zone()) ZoneList<Statement*>(16, zone());
     bool ok = true;
     int beg_pos = scanner()->location().beg_pos;
     if (info->is_module()) {
       DCHECK(allow_harmony_modules());
       ParseModuleItemList(body, &ok);
     } else {
-      Scope* eval_scope = nullptr;
-      ParseStatementList(body, Token::EOS, info->is_eval(), &eval_scope, &ok);
-      if (eval_scope != nullptr)
-        eval_scope->set_end_position(scanner()->peek_location().beg_pos);
+      ParseStatementList(body, Token::EOS, &ok);
     }
 
     // The parser will peek but not consume EOS.  Our scope logically goes all
     // the way to the EOS, though.
     scope->set_end_position(scanner()->peek_location().beg_pos);
 
     if (ok && is_strict(language_mode())) {
       CheckStrictOctalLiteral(beg_pos, scanner()->location().end_pos, &ok);
       CheckConflictingVarDeclarations(scope_, &ok);
     }
@@ skipping 165 matching lines @@
 
   if (result != NULL) {
     Handle<String> inferred_name(shared_info->inferred_name());
     result->set_inferred_name(inferred_name);
   }
   return result;
 }
 
 
 void* Parser::ParseStatementList(ZoneList<Statement*>* body, int end_token,
-                                 bool is_eval, Scope** eval_scope, bool* ok) {
+                                 bool* ok) {
   // StatementList ::
   //   (StatementListItem)* <end_token>
 
   // Allocate a target stack to use for this set of source
   // elements. This way, all scripts and functions get their own
   // target stack thus avoiding illegal breaks and continues across
   // functions.
   TargetScope scope(&this->target_stack_);
 
   DCHECK(body != NULL);
@@ skipping 51 matching lines @@
         bool use_strong_found =
             allow_strong_mode() &&
             literal->raw_value()->AsString() ==
                 ast_value_factory()->use_strong_string() &&
             token_loc.end_pos - token_loc.beg_pos ==
                 ast_value_factory()->use_strong_string()->length() + 2;
         if (use_strict_found || use_strong_found) {
           // Strong mode implies strict mode. If there are several "use strict"
           // / "use strong" directives, do the strict mode changes only once.
           if (is_sloppy(scope_->language_mode())) {
-            // TODO(mstarzinger): Global strict eval calls, need their own scope
-            // as specified in ES5 10.4.2(3). The correct fix would be to always
-            // add this scope in DoParseProgram(), but that requires adaptations
-            // all over the code base, so we go with a quick-fix for now.
-            // In the same manner, we have to patch the parsing mode.
-            if (is_eval && !scope_->is_eval_scope()) {
-              DCHECK(scope_->is_script_scope());
-              Scope* scope = NewScope(scope_, EVAL_SCOPE);
-              scope->set_start_position(scope_->start_position());
-              scope->set_end_position(scope_->end_position());
-              scope_ = scope;
-              if (eval_scope != NULL) {
-                // Caller will correct the positions of the ad hoc eval scope.
-                *eval_scope = scope;
-              }
-              mode_ = PARSE_EAGERLY;
-            }
             scope_->SetLanguageMode(static_cast<LanguageMode>(
                 scope_->language_mode() | STRICT_BIT));
           }
 
           if (use_strong_found) {
             scope_->SetLanguageMode(static_cast<LanguageMode>(
                 scope_->language_mode() | STRONG_BIT));
           }
+          // Because declarations in strict eval code don't leak into the scope
+          // of the eval call, it is likely that functions declared in strict
+          // eval code will be used within the eval code, so lazy parsing is
+          // probably not a win.  Also, resolution of "var" bindings defined in
+          // strict eval code from within nested functions is currently broken
+          // with the pre-parser; lazy parsing of strict eval code causes
+          // regress/regress-crbug-135066.js to fail.
+          if (scope_->is_eval_scope()) mode_ = PARSE_EAGERLY;
         } else if (literal->raw_value()->AsString() ==
                        ast_value_factory()->use_asm_string() &&
                    token_loc.end_pos - token_loc.beg_pos ==
                        ast_value_factory()->use_asm_string()->length() + 2) {
           // Store the usage count; The actual use counter on the isolate is
           // incremented after parsing is done.
           ++use_counts_[v8::Isolate::kUseAsm];
           scope_->SetAsmModule();
         }
       } else {
@@ skipping 2959 matching lines @@
     Assignment* assignment = factory()->NewAssignment(
         Token::INIT_VAR, init_proxy, allocation, RelocInfo::kNoPosition);
     VariableProxy* get_proxy = factory()->NewVariableProxy(
         function_state_->generator_object_variable());
     Yield* yield = factory()->NewYield(
         get_proxy, assignment, Yield::kInitial, RelocInfo::kNoPosition);
     body->Add(factory()->NewExpressionStatement(
         yield, RelocInfo::kNoPosition), zone());
   }
 
-  ParseStatementList(body, Token::RBRACE, false, NULL, CHECK_OK);
+  ParseStatementList(body, Token::RBRACE, CHECK_OK);
 
   if (IsGeneratorFunction(kind)) {
     VariableProxy* get_proxy = factory()->NewVariableProxy(
         function_state_->generator_object_variable());
     Expression* undefined =
         factory()->NewUndefinedLiteral(RelocInfo::kNoPosition);
     Yield* yield = factory()->NewYield(get_proxy, undefined, Yield::kFinal,
                                        RelocInfo::kNoPosition);
     body->Add(factory()->NewExpressionStatement(
         yield, RelocInfo::kNoPosition), zone());
@@ skipping 1546 matching lines @@
 
 Expression* Parser::SpreadCallNew(Expression* function,
                                   ZoneList<v8::internal::Expression*>* args,
                                   int pos) {
   args->InsertAt(0, function, zone());
 
   return factory()->NewCallRuntime(
       ast_value_factory()->reflect_construct_string(), NULL, args, pos);
 }
 } }  // namespace v8::internal