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

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 3ea5b19c0743a3b700350233b7e4712b33ccd711..3f7cf5723b6233076b5a62c49f716a2eecf6ced5 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -28,6 +28,7 @@
 #include "src/counters-inl.h"
 #include "src/counters.h"
 #include "src/date.h"
+#include "src/debug/debug-evaluate.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/elements.h"
@@ -13940,6 +13941,21 @@ String* SharedFunctionInfo::DebugName() {
   return String::cast(n);
 }
 
+bool SharedFunctionInfo::IsReadOnly() {
+  if (!is_readonly_computed()) {
+    Isolate* isolate = GetIsolate();
+    if (HasBytecodeArray()) {
+      DisallowHeapAllocation not_handlified;
+      Handle<BytecodeArray> array(bytecode_array(), isolate);

[jgruber, 2017/01/10 12:46:38]

Do we need to create this handle?

And what about adding IsReadOnly to BytecodeArray instead of DebugEvaluate?
Seems more natural and we could avoid additional includes here and in
debug-evaluate.

[Yang, 2017/01/10 14:14:07]

We need to create the handle for the BytecodeArrayIterator.

I'd like to keep it this way. In fact, I should move the whitelist to src/debug.

+      set_is_readonly(DebugEvaluate::IsReadOnly(array));
+    } else {
+      set_is_readonly(false);
+    }
+    set_is_readonly_computed(true);
+  }
+  return is_readonly();
+}
+
 // The filter is a pattern that matches function names in this way:
 //   "*"      all; the default
 //   "-"      all but the top-level function