Create ScopeInfos while analyzing the Scope chain

src/ast/scopes.h

 // 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.
 
 #ifndef V8_AST_SCOPES_H_
 #define V8_AST_SCOPES_H_
 
 #include "src/ast/ast.h"
 #include "src/base/hashmap.h"
 #include "src/globals.h"
@@ skipping 72 matching lines @@
     void Reparent(DeclarationScope* new_parent) const;
 
    private:
     Scope* outer_scope_;
     Scope* top_inner_scope_;
     VariableProxy* top_unresolved_;
     int top_local_;
     int top_decl_;
   };
 
-  // Compute top scope and allocate variables. For lazy compilation the top
-  // scope only contains the single lazily compiled function, so this
-  // doesn't re-allocate variables repeatedly.
-  static void Analyze(ParseInfo* info);
-
   enum class DeserializationMode { kDeserializeOffHeap, kKeepScopeInfo };
 
   static Scope* DeserializeScopeChain(Isolate* isolate, Zone* zone,
                                       Context* context,
                                       DeclarationScope* script_scope,
                                       AstValueFactory* ast_value_factory,
                                       DeserializationMode deserialization_mode);
 
   // Checks if the block scope is redundant, i.e. it does not contain any
   // block scoped declarations. In that case it is removed from the scope
@@ skipping 264 matching lines @@
   // function, or eval scope. Same as DeclarationScope(), but skips declaration
   // "block" scopes. Used for differentiating associated function objects (i.e.,
   // the scope for which a function prologue allocates a context) or declaring
   // temporaries.
   DeclarationScope* GetClosureScope();
 
   // Find the first (non-arrow) function or script scope.  This is where
   // 'this' is bound, and what determines the function kind.
   DeclarationScope* GetReceiverScope();
 
-  // Creates a scope info if it doesn't already exist.
-  Handle<ScopeInfo> GetScopeInfo(Isolate* isolate);
-
-  // GetScopeInfo() must have been called once to create the ScopeInfo.
+  // Analyze() must have been called once to create the ScopeInfo.
   Handle<ScopeInfo> scope_info() {
     DCHECK(!scope_info_.is_null());
     return scope_info_;
   }
 
   // ---------------------------------------------------------------------------
   // Strict mode support.
   bool IsDeclared(const AstRawString* name) {
     // During formal parameter list parsing the scope only contains
     // two variables inserted at initialization: "this" and "arguments".
@@ skipping 34 matching lines @@
                     VariableMode mode, Variable::Kind kind,
                     InitializationFlag initialization_flag,
                     MaybeAssignedFlag maybe_assigned_flag = kNotAssigned) {
     bool added;
     Variable* var =
         variables_.Declare(zone, scope, name, mode, kind, initialization_flag,
                            maybe_assigned_flag, &added);
     if (added) locals_.Add(var, zone);
     return var;
   }
+
+  // This method should only be invoked on scopes created during parsing (i.e.,
+  // not deserialized from a context). Also, since NeedsContext() is only
+  // returning a valid result after variables are resolved, NeedsScopeInfo()
+  // should also be invoked after resolution.
+  bool NeedsScopeInfo() const {
+    DCHECK(!already_resolved_);
+    return NeedsContext() || is_script_scope() || is_function_scope() ||
+           is_eval_scope() || is_module_scope();
+  }
+
   Zone* zone_;
 
   // Scope tree.
   Scope* outer_scope_;  // the immediately enclosing outer scope, or NULL
   Scope* inner_scope_;  // an inner scope of this scope
   Scope* sibling_;  // a sibling inner scope of the outer scope of this scope.
 
   // The variables declared in this scope:
   //
   // All user-declared variables (incl. parameters).  For script scopes
@@ skipping 85 matching lines @@
   bool MustAllocateInContext(Variable* var);
 
   // Variable allocation.
   void AllocateStackSlot(Variable* var);
   void AllocateHeapSlot(Variable* var);
   void AllocateNonParameterLocal(Variable* var);
   void AllocateDeclaredGlobal(Variable* var);
   void AllocateNonParameterLocalsAndDeclaredGlobals();
   void AllocateVariablesRecursively();
 
+  void AllocateScopeInfosRecursively(Isolate* isolate, bool for_debugger);
+
   // Construct a scope based on the scope info.
   Scope(Zone* zone, ScopeType type, Handle<ScopeInfo> scope_info);
 
   // Construct a catch scope with a binding for the name.
   Scope(Zone* zone, const AstRawString* catch_variable_name);
 
   void AddInnerScope(Scope* inner_scope) {
     inner_scope->sibling_ = inner_scope_;
     inner_scope_ = inner_scope;
     inner_scope->outer_scope_ = this;
@@ skipping 182 matching lines @@
 
   void DeclareSloppyBlockFunction(const AstRawString* name,
                                   SloppyBlockFunctionStatement* statement) {
     sloppy_block_function_map_.Declare(zone(), name, statement);
   }
 
   SloppyBlockFunctionMap* sloppy_block_function_map() {
     return &sloppy_block_function_map_;
   }
 
-  // Resolve and fill in the allocation information for all variables
-  // in this scopes. Must be called *after* all scopes have been
-  // processed (parsed) to ensure that unresolved variables can be
-  // resolved properly.
-  //
-  // In the case of code compiled and run using 'eval', the context
-  // parameter is the context in which eval was called.  In all other
-  // cases the context parameter is an empty handle.
-  void AllocateVariables(ParseInfo* info);
+  // Compute top scope and allocate variables. For lazy compilation the top
+  // scope only contains the single lazily compiled function, so this
+  // doesn't re-allocate variables repeatedly.
+  static void Analyze(ParseInfo* info);
+
+  // Version used by the debugger that creates extra ScopeInfos.
+  static void AnalyzeForDebugger(ParseInfo* info);
 
   // To be called during parsing. Do just enough scope analysis that we can
   // discard the Scope for lazily compiled functions. In particular, this
   // records variables which cannot be resolved inside the Scope (we don't yet
   // know what they will resolve to since the outer Scopes are incomplete) and
   // migrates them into migrate_to.
   void AnalyzePartially(DeclarationScope* migrate_to,
                         AstNodeFactory* ast_node_factory);
 
   Handle<StringSet> CollectNonLocals(ParseInfo* info,
@@ skipping 18 matching lines @@
   void PrintParameters();
 #endif
 
   void AllocateLocals();
   void AllocateParameterLocals();
   void AllocateReceiver();
 
  private:
   void AllocateParameter(Variable* var, int index);
 
+  // Resolve and fill in the allocation information for all variables
+  // in this scopes. Must be called *after* all scopes have been
+  // processed (parsed) to ensure that unresolved variables can be
+  // resolved properly.
+  //
+  // In the case of code compiled and run using 'eval', the context
+  // parameter is the context in which eval was called.  In all other
+  // cases the context parameter is an empty handle.
+  void AllocateVariables(ParseInfo* info, bool for_debugger);
+
   void SetDefaults();
 
   // If the scope is a function scope, this is the function kind.
   const FunctionKind function_kind_;
 
   bool has_simple_parameters_ : 1;
   // This scope contains an "use asm" annotation.
   bool asm_module_ : 1;
   // This scope's outer context is an asm module.
   bool asm_function_ : 1;
@@ skipping 38 matching lines @@
   void AllocateModuleVariables();
 
  private:
   ModuleDescriptor* module_descriptor_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_SCOPES_H_