[strong] Stricter check for referring to other classes inside methods.

src/variables.h

 // Copyright 2011 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.
 
 #ifndef V8_VARIABLES_H_
 #define V8_VARIABLES_H_
 
 #include "src/ast-value-factory.h"
 #include "src/zone.h"
 
 namespace v8 {
 namespace internal {
 
 // The AST refers to variables via VariableProxies - placeholders for the actual
 // variables. Variables themselves are never directly referred to from the AST,
 // they are maintained by scopes, and referred to from VariableProxies and Slots
 // after binding and variable allocation.
 
+class ClassVariable;
+
 class Variable: public ZoneObject {
  public:
   enum Kind { NORMAL, FUNCTION, CLASS, THIS, NEW_TARGET, ARGUMENTS };
 
   enum Location {
     // Before and during variable allocation, a variable whose location is
     // not yet determined.  After allocation, a variable looked up as a
     // property on the global object (and possibly absent).  name() is the
     // variable name, index() is invalid.
     UNALLOCATED,
@@ skipping 15 matching lines @@
     // A named slot in a heap context.  name() is the variable name in the
     // context object on the heap, with lookup starting at the current
     // context.  index() is invalid.
     LOOKUP
   };
 
   Variable(Scope* scope, const AstRawString* name, VariableMode mode, Kind kind,
            InitializationFlag initialization_flag,
            MaybeAssignedFlag maybe_assigned_flag = kNotAssigned);
 
+  virtual ~Variable() {}
+
   // Printing support
   static const char* Mode2String(VariableMode mode);
 
   // The source code for an eval() call may refer to a variable that is
   // in an outer scope about which we don't know anything (it may not
   // be the script scope). scope() is NULL in that case. Currently the
   // scope is only used to follow the context chain length.
   Scope* scope() const { return scope_; }
 
   Handle<String> name() const { return name_->string(); }
@@ skipping 31 matching lines @@
   bool binding_needs_init() const {
     return initialization_flag_ == kNeedsInitialization;
   }
 
   bool is_function() const { return kind_ == FUNCTION; }
   bool is_class() const { return kind_ == CLASS; }
   bool is_this() const { return kind_ == THIS; }
   bool is_new_target() const { return kind_ == NEW_TARGET; }
   bool is_arguments() const { return kind_ == ARGUMENTS; }
 
+  ClassVariable* AsClassVariable() {
+    DCHECK(is_class());
+    return reinterpret_cast<ClassVariable*>(this);
+  }
+
   // True if the variable is named eval and not known to be shadowed.
   bool is_possibly_eval(Isolate* isolate) const {
     return IsVariable(isolate->factory()->eval_string());
   }
 
   Variable* local_if_not_shadowed() const {
     DCHECK(mode_ == DYNAMIC_LOCAL && local_if_not_shadowed_ != NULL);
     return local_if_not_shadowed_;
   }
 
@@ skipping 53 matching lines @@
   // binding scope (exclusive).
   Variable* local_if_not_shadowed_;
 
   // Usage info.
   bool force_context_allocation_;  // set by variable resolver
   bool is_used_;
   InitializationFlag initialization_flag_;
   MaybeAssignedFlag maybe_assigned_;
 };
 
+class ClassVariable : public Variable {
+ public:
+  ClassVariable(Scope* scope, const AstRawString* name, VariableMode mode,
+                Kind kind, InitializationFlag initialization_flag,
+                MaybeAssignedFlag maybe_assigned_flag = kNotAssigned,
+                int declaration_group_start = -1)
+      : Variable(scope, name, mode, kind, initialization_flag,
+                 maybe_assigned_flag),
+        declaration_group_start_(declaration_group_start),
+        corresponding_outer_class_variable_(nullptr) {}
 
+  int declaration_group_start() const { return declaration_group_start_; }
+
+  ClassVariable* corresponding_outer_class_variable() const {
+    return corresponding_outer_class_variable_;
+  }
+  void set_corresponding_outer_class_variable(ClassVariable* var) {
+    corresponding_outer_class_variable_ = var;
+  }
+
+ private:
+  // For classes we keep track of consecutive groups of delcarations. They are
+  // needed for strong mode scoping checks. TODO(marja, rossberg): Implement
+  // checks for functions too.
+  int declaration_group_start_;
+  ClassVariable* corresponding_outer_class_variable_;
+};
 } }  // namespace v8::internal
 
 #endif  // V8_VARIABLES_H_