Add a runtime flag to control availability of dart:mirrors.

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 46 matching lines @@
     "with the type arguments of its super type.");
 DEFINE_FLAG(bool, show_internal_names, false,
     "Show names of internal classes (e.g. \"OneByteString\") in error messages "
     "instead of showing the corresponding interface names (e.g. \"String\")");
 DEFINE_FLAG(bool, throw_on_javascript_int_overflow, false,
     "Throw an exception when the result of an integer calculation will not "
     "fit into a javascript integer.");
 DEFINE_FLAG(bool, use_field_guards, true, "Guard field cids.");
 DEFINE_FLAG(bool, use_lib_cache, true, "Use library name cache");
 DEFINE_FLAG(bool, trace_field_guards, false, "Trace changes in field's cids.");
+DEFINE_FLAG(bool, use_mirrors, true, "Make dart:mirrors available.");
 
 DECLARE_FLAG(bool, error_on_bad_override);
 DECLARE_FLAG(bool, trace_compiler);
 DECLARE_FLAG(bool, trace_deoptimization);
 DECLARE_FLAG(bool, trace_deoptimization_verbose);
 DECLARE_FLAG(bool, show_invisible_frames);
 DECLARE_FLAG(charp, coverage_dir);
 DECLARE_FLAG(bool, write_protect_code);
 
 static const char* kGetterPrefix = "get:";
@@ skipping 1104 matching lines @@
   cls.set_is_prefinalized();
   RegisterPrivateClass(cls, Symbols::FunctionImpl(), core_lib);
   pending_classes.Add(cls);
   type = Type::NewNonParameterizedType(cls);
   object_store->set_function_impl_type(type);
 
   cls = Class::New<WeakProperty>();
   object_store->set_weak_property_class(cls);
   RegisterPrivateClass(cls, Symbols::_WeakProperty(), core_lib);
 
-  // Pre-register the mirrors library so we can place the vm class
-  // MirrorReference there rather than the core library.
-  lib = Library::LookupLibrary(Symbols::DartMirrors());
-  if (lib.IsNull()) {
-    lib = Library::NewLibraryHelper(Symbols::DartMirrors(), true);
-    lib.SetLoadRequested();
-    lib.Register();
-    object_store->set_bootstrap_library(ObjectStore::kMirrors, lib);
+  if (FLAG_use_mirrors) {
+    // Pre-register the mirrors library so we can place the vm class
+    // MirrorReference there rather than the core library.
+    lib = Library::LookupLibrary(Symbols::DartMirrors());
+    if (lib.IsNull()) {
+      lib = Library::NewLibraryHelper(Symbols::DartMirrors(), true);
+      lib.SetLoadRequested();
+      lib.Register();
+      object_store->set_bootstrap_library(ObjectStore::kMirrors, lib);
+    }
+    ASSERT(!lib.IsNull());
+    ASSERT(lib.raw() == Library::MirrorsLibrary());
+
+    cls = Class::New<MirrorReference>();
+    RegisterPrivateClass(cls, Symbols::_MirrorReference(), lib);
+  } else {
+    lib = Library::LookupLibrary(Symbols::DartMirrors());
+    ASSERT(lib.IsNull());
   }
-  ASSERT(!lib.IsNull());
-  ASSERT(lib.raw() == Library::MirrorsLibrary());
-
-  cls = Class::New<MirrorReference>();
-  RegisterPrivateClass(cls, Symbols::_MirrorReference(), lib);
 
   // Pre-register the collection library so we can place the vm class
   // LinkedHashMap there rather than the core library.
   lib = Library::LookupLibrary(Symbols::DartCollection());
   if (lib.IsNull()) {
     lib = Library::NewLibraryHelper(Symbols::DartCollection(), true);
     lib.SetLoadRequested();
     lib.Register();
     object_store->set_bootstrap_library(ObjectStore::kCollection, lib);
   }
@@ skipping 19575 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart