- Implement a first cut for const String.env in the VM to allow

runtime/lib/integers.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/bootstrap_natives.h"
 
+#include "include/dart_api.h"
 #include "vm/bigint_operations.h"
 #include "vm/dart_entry.h"
+#include "vm/dart_api_impl.h"
 #include "vm/exceptions.h"
+#include "vm/isolate.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, trace_intrinsified_natives, false,
     "Report if any of the intrinsified natives are called");
 
@@ skipping 199 matching lines @@
     }
     String& temp = String::Handle();
     temp = String::Concat(Symbols::Dash(), *int_string);
     return Integer::New(temp);
   }
 
   return Object::null();
 }
 
 
+DEFINE_NATIVE_ENTRY(Integer_fromEnvironment, 3) {
+  GET_NON_NULL_NATIVE_ARGUMENT(String, name, arguments->NativeArgAt(1));
+  GET_NATIVE_ARGUMENT(Integer, default_value, arguments->NativeArgAt(2));
+  // Call the embedder to supply us with the environment.
+  Dart_EnvironmentCallback callback = isolate->environment_callback();
+  if (callback != NULL) {
+    Dart_Handle result = callback(kIntegerEnvironment,
+                                  Api::NewHandle(isolate, name.raw()));
+    if (!Dart_IsError(result)) {
+      const Object& value = Object::Handle(isolate, Api::UnwrapHandle(result));
+      if (value.IsString()) {
+        // TODO(iposva): Handle errors such as malformed integers.
+        return Integer::NewCanonical(String::Cast(value));
+      }
+    }
+  }
+  return default_value.raw();
+}
+
+
 // Passing true for 'silent' prevents throwing JavascriptIntegerOverflow.
 static RawInteger* ShiftOperationHelper(Token::Kind kind,
                                         const Integer& value,
                                         const Smi& amount,
                                         const bool silent = false) {
   if (amount.Value() < 0) {
     Exceptions::ThrowArgumentError(amount);
   }
   if (value.IsSmi()) {
     const Smi& smi_value = Smi::Cast(value);
@@ skipping 162 matching lines @@
   // Use the preallocated out of memory exception to avoid calling
   // into dart code or allocating any code.
   const Instance& exception =
       Instance::Handle(isolate->object_store()->out_of_memory());
   Exceptions::Throw(exception);
   UNREACHABLE();
   return 0;
 }
 
 }  // namespace dart