[debugger] expose side-effect free evaluate to inspector.

src/debug/debug-evaluate.cc

 // 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.
 
 #include "src/debug/debug-evaluate.h"
 
 #include "src/accessors.h"
 #include "src/compiler.h"
 #include "src/contexts.h"
 #include "src/debug/debug-frames.h"
@@ skipping 23 matching lines @@
   while (top != NULL && IsDebugContext(isolate, *top->context())) {
     top = top->prev();
   }
   if (top != NULL) isolate->set_context(*top->context());
 
   // Get the native context now set to the top context from before the
   // debugger was invoked.
   Handle<Context> context = isolate->native_context();
   Handle<JSObject> receiver(context->global_proxy());
   Handle<SharedFunctionInfo> outer_info(context->closure()->shared(), isolate);
-  return Evaluate(isolate, outer_info, context, receiver, source);
+  return Evaluate(isolate, outer_info, context, receiver, source, false);
 }
 
 MaybeHandle<Object> DebugEvaluate::Local(Isolate* isolate,
                                          StackFrame::Id frame_id,
                                          int inlined_jsframe_index,
-                                         Handle<String> source) {
+                                         Handle<String> source,
+                                         bool throw_on_side_effect) {
   // Handle the processing of break.
   DisableBreak disable_break_scope(isolate->debug());
 
   // Get the frame where the debugging is performed.
   StackTraceFrameIterator it(isolate, frame_id);
   if (!it.is_javascript()) return isolate->factory()->undefined_value();
   JavaScriptFrame* frame = it.javascript_frame();
 
   // Traverse the saved contexts chain to find the active context for the
   // selected frame.
   SaveContext* save =
       DebugFrameHelper::FindSavedContextForFrame(isolate, frame);
   SaveContext savex(isolate);
   isolate->set_context(*(save->context()));
 
   // This is not a lot different than DebugEvaluate::Global, except that
   // variables accessible by the function we are evaluating from are
   // materialized and included on top of the native context. Changes to
   // the materialized object are written back afterwards.
   // Note that the native context is taken from the original context chain,
   // which may not be the current native context of the isolate.
   ContextBuilder context_builder(isolate, frame, inlined_jsframe_index);
   if (isolate->has_pending_exception()) return MaybeHandle<Object>();
 
   Handle<Context> context = context_builder.evaluation_context();
   Handle<JSObject> receiver(context->global_proxy());
-  MaybeHandle<Object> maybe_result = Evaluate(
-      isolate, context_builder.outer_info(), context, receiver, source);
+  MaybeHandle<Object> maybe_result =
+      Evaluate(isolate, context_builder.outer_info(), context, receiver, source,
+               throw_on_side_effect);
   if (!maybe_result.is_null()) context_builder.UpdateValues();
   return maybe_result;
 }
 
 
 // Compile and evaluate source for the given context.
 MaybeHandle<Object> DebugEvaluate::Evaluate(
     Isolate* isolate, Handle<SharedFunctionInfo> outer_info,
-    Handle<Context> context, Handle<Object> receiver, Handle<String> source) {
+    Handle<Context> context, Handle<Object> receiver, Handle<String> source,
+    bool throw_on_side_effect) {
   Handle<JSFunction> eval_fun;
   ASSIGN_RETURN_ON_EXCEPTION(
       isolate, eval_fun,
       Compiler::GetFunctionFromEval(source, outer_info, context, SLOPPY,
                                     NO_PARSE_RESTRICTION, kNoSourcePosition,
                                     kNoSourcePosition),
       Object);
 
   Handle<Object> result;
   {
-    NoSideEffectScope no_side_effect(isolate,
-                                     FLAG_side_effect_free_debug_evaluate);
+    NoSideEffectScope no_side_effect(isolate, throw_on_side_effect);
     ASSIGN_RETURN_ON_EXCEPTION(
         isolate, result, Execution::Call(isolate, eval_fun, receiver, 0, NULL),
         Object);
   }
 
   // Skip the global proxy as it has no properties and always delegates to the
   // real global object.
   if (result->IsJSGlobalProxy()) {
     PrototypeIterator iter(isolate, Handle<JSGlobalProxy>::cast(result));
     // TODO(verwaest): This will crash when the global proxy is detached.
@@ skipping 427 matching lines @@
 
   if (FLAG_trace_side_effect_free_debug_evaluate) {
     PrintF("[debug-evaluate] API Callback at %p may cause side effect.\n",
            reinterpret_cast<void*>(function_addr));
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8