Add read-only environment variable access.

runtime/bin/platform.cc

Index: runtime/bin/platform.cc
diff --git a/runtime/bin/platform.cc b/runtime/bin/platform.cc
index f8398f415174719fb6ffcb594c9d64983281b8b0..34c29100272deb6062fea5d42304670527491eff 100644
--- a/runtime/bin/platform.cc
+++ b/runtime/bin/platform.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
@@ -39,3 +39,34 @@ void FUNCTION_NAME(Platform_LocalHostname)(Dart_NativeArguments args) {
   }
   Dart_ExitScope();
 }
+
+
+void FUNCTION_NAME(Platform_Environment)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  intptr_t count = 0;
+  char** env = Platform::Environment(&count);
+  if (env == NULL) {
+    OSError error(-1,
+                  "Failed to retrieve environment variables.",
+                  OSError::kUnknown);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError(&error));
+  } else {
+    Dart_Handle result = Dart_NewList(count);
+    if (Dart_IsError(result)) {
+      Dart_PropagateError(result);
+    }
+    for (intptr_t i = 0; i < count; i++) {
+      Dart_Handle str = Dart_NewString(env[i]);
+      if (Dart_IsError(str)) {
+        Dart_PropagateError(str);
+      }
+      Dart_Handle error = Dart_ListSetAt(result, i, str);
+      if (Dart_IsError(error)) {
+        Dart_PropagateError(error);
+      }
+    }
+    delete[] env;
+    Dart_SetReturnValue(args, result);
+  }
+  Dart_ExitScope();
+}