Debugger: refactor ScopeIterator, FrameInspector and DebugEvaluate.

src/debug/debug-scopes.h

+// Copyright 2015 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_DEBUG_DEBUG_SCOPES_H_
+#define V8_DEBUG_DEBUG_SCOPES_H_
+
+#include "src/debug/debug-frames.h"
+#include "src/frames.h"
+
+namespace v8 {
+namespace internal {
+
+// Iterate over the actual scopes visible from a stack frame or from a closure.
+// The iteration proceeds from the innermost visible nested scope outwards.
+// All scopes are backed by an actual context except the local scope,
+// which is inserted "artificially" in the context chain.
+class ScopeIterator {
+ public:
+  enum ScopeType {
+    ScopeTypeGlobal = 0,
+    ScopeTypeLocal,
+    ScopeTypeWith,
+    ScopeTypeClosure,
+    ScopeTypeCatch,
+    ScopeTypeBlock,
+    ScopeTypeScript,
+    ScopeTypeModule
+  };
+
+  static const int kScopeDetailsTypeIndex = 0;
+  static const int kScopeDetailsObjectIndex = 1;
+  static const int kScopeDetailsSize = 2;
+
+  ScopeIterator(Isolate* isolate, FrameInspector* frame_inspector,
+                bool ignore_nested_scopes = false);
+
+  ScopeIterator(Isolate* isolate, Handle<JSFunction> function);
+
+  MUST_USE_RESULT MaybeHandle<JSObject> MaterializeScopeDetails();
+
+  // More scopes?
+  bool Done() {
+    DCHECK(!failed_);
+    return context_.is_null();
+  }
+
+  bool Failed() { return failed_; }
+
+  // Move to the next scope.
+  void Next();
+
+  // Return the type of the current scope.
+  ScopeType Type();
+
+  // Return the JavaScript object with the content of the current scope.
+  MaybeHandle<JSObject> ScopeObject();
+
+  bool HasContext();
+
+  // Set variable value and return true on success.
+  bool SetVariableValue(Handle<String> variable_name, Handle<Object> new_value);
+
+  Handle<ScopeInfo> CurrentScopeInfo();
+
+  // Return the context for this scope. For the local context there might not
+  // be an actual context.
+  Handle<Context> CurrentContext();
+
+#ifdef DEBUG
+  // Debug print of the content of the current scope.
+  void DebugPrint();
+#endif
+
+ private:
+  Isolate* isolate_;
+  FrameInspector* const frame_inspector_;
+  Handle<Context> context_;
+  List<Handle<ScopeInfo> > nested_scope_chain_;
+  bool seen_script_scope_;
+  bool failed_;
+
+  inline JavaScriptFrame* GetFrame() {
+    return frame_inspector_->GetArgumentsFrame();
+  }
+
+  inline Handle<JSFunction> GetFunction() {
+    return Handle<JSFunction>(
+        JSFunction::cast(frame_inspector_->GetFunction()));
+  }
+
+  void RetrieveScopeChain(Scope* scope, Handle<SharedFunctionInfo> shared_info);
+
+  MUST_USE_RESULT MaybeHandle<JSObject> MaterializeScriptScope();
+  MUST_USE_RESULT MaybeHandle<JSObject> MaterializeLocalScope();
+  MUST_USE_RESULT MaybeHandle<JSObject> MaterializeModuleScope();
+  Handle<JSObject> MaterializeClosure();
+  Handle<JSObject> MaterializeCatchScope();
+  Handle<JSObject> MaterializeBlockScope();
+
+  bool SetLocalVariableValue(Handle<String> variable_name,
+                             Handle<Object> new_value);
+  bool SetBlockVariableValue(Handle<String> variable_name,
+                             Handle<Object> new_value);
+  bool SetClosureVariableValue(Handle<String> variable_name,
+                               Handle<Object> new_value);
+  bool SetScriptVariableValue(Handle<String> variable_name,
+                              Handle<Object> new_value);
+  bool SetCatchVariableValue(Handle<String> variable_name,
+                             Handle<Object> new_value);
+  bool SetContextLocalValue(Handle<ScopeInfo> scope_info,
+                            Handle<Context> context,
+                            Handle<String> variable_name,
+                            Handle<Object> new_value);
+
+  void CopyContextLocalsToScopeObject(Handle<ScopeInfo> scope_info,
+                                      Handle<Context> context,
+                                      Handle<JSObject> scope_object);
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ScopeIterator);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_DEBUG_DEBUG_SCOPES_H_