Disallow eval on lists containing non-instances.

runtime/vm/service.cc

Index: runtime/vm/service.cc
===================================================================
--- runtime/vm/service.cc	(revision 36381)
+++ runtime/vm/service.cc	(working copy)
@@ -851,6 +851,23 @@
 }
 
 
+static bool IsInternal(const Object& obj) {

[turnidge, 2014/05/20 23:21:34]

The name is a bit vague.  Not sure what to suggest.  Maybe something like
"PointsToNonInstanceObjects"

[koda, 2014/05/21 15:49:23]

Done.

+  if (obj.IsArray()) {

[turnidge, 2014/05/20 23:21:34]

Do you need to add a case for obj.IsGrowableArray as well?  Not sure if we use
those internally or not.

[koda, 2014/05/21 15:49:23]

Good point. Done.

+    const Array& array = Array::Cast(obj);
+    Object& element = Object::Handle();
+    for (intptr_t i = 0; i < array.Length(); ++i) {
+      element = array.At(i);
+      if (!element.IsInstance()) {
+        return true;
+      }
+    }
+    return false;
+  } else {
+    return !obj.IsInstance();
+  }
+}
+
+
 static bool HandleInstanceCommands(Isolate* isolate,
                                    const Object& obj,
                                    JSONStream* js,
@@ -876,6 +893,10 @@
                          js->num_arguments());
       return true;
     }
+    if (IsInternal(obj)) {
+      PrintError(js, "attempt to evaluate against internal VM object\n");
+      return true;
+    }
     const char* expr = js->LookupOption("expr");
     if (expr == NULL) {
       PrintError(js, "eval expects an 'expr' option\n",