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

runtime/lib/integers.cc

Index: runtime/lib/integers.cc
===================================================================
--- runtime/lib/integers.cc	(revision 28841)
+++ runtime/lib/integers.cc	(working copy)
@@ -4,9 +4,12 @@
 
 #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"
@@ -226,6 +229,26 @@
 }
 
 
+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,