Add read-only environment variable access.

runtime/bin/platform.cc

-// 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.
 
 #include "bin/file.h"
 #include "bin/platform.h"
 #include "include/dart_api.h"
 
 
 void FUNCTION_NAME(Platform_NumberOfProcessors)(Dart_NativeArguments args) {
   Dart_EnterScope();
@@ skipping 20 matching lines @@
   Dart_EnterScope();
   const intptr_t HOSTNAME_LENGTH = 256;
   char hostname[HOSTNAME_LENGTH];
   if (Platform::LocalHostname(hostname, HOSTNAME_LENGTH)) {
     Dart_SetReturnValue(args, Dart_NewString(hostname));
   } else {
     Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
   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();
+}