[debugger] infrastructure for side-effect-free debug-evaluate.

src/debug/debug-evaluate.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_EVALUATE_H_
 #define V8_DEBUG_DEBUG_EVALUATE_H_
 
 #include "src/frames.h"
 #include "src/objects.h"
 
 namespace v8 {
 namespace internal {
 
 class DebugEvaluate : public AllStatic {
  public:
   static MaybeHandle<Object> Global(Isolate* isolate, Handle<String> source);
 
   // Evaluate a piece of JavaScript in the context of a stack frame for
   // debugging.  Things that need special attention are:
   // - Parameters and stack-allocated locals need to be materialized.  Altered
   //   values need to be written back to the stack afterwards.
   // - The arguments object needs to materialized.
   static MaybeHandle<Object> Local(Isolate* isolate, StackFrame::Id frame_id,
                                    int inlined_jsframe_index,
                                    Handle<String> source);
 
+  static bool HasNoSideEffect(Handle<BytecodeArray> bytecode_array);
+
  private:
   // This class builds a context chain for evaluation of expressions
   // in debugger.
   // The scope chain leading up to a breakpoint where evaluation occurs
   // looks like:
   // - [a mix of with, catch and block scopes]
   //    - [function stack + context]
   //      - [outer context]
   // The builder materializes all stack variables into properties of objects;
   // the expression is then evaluated as if it is inside a series of 'with'
@@ skipping 47 matching lines @@
                                       Handle<Context> context,
                                       Handle<Object> receiver,
                                       Handle<String> source);
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_DEBUG_DEBUG_EVALUATE_H_