diff --git a/com.google.eclipse.protobuf/descriptor.proto b/com.google.eclipse.protobuf/descriptor.proto
new file mode 100644
index 0000000..4eeb43b
--- /dev/null
+++ b/com.google.eclipse.protobuf/descriptor.proto
@@ -0,0 +1,538 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+//
+// The messages in this file describe the definitions found in .proto files.
+// A valid .proto file can be translated directly to a FileDescriptorProto
+// without any other information (e.g. without reading its imports).
+
+
+
+package google.protobuf;
+option java_package = "com.google.protobuf";
+option java_outer_classname = "DescriptorProtos";
+
+// descriptor.proto must be optimized for speed because reflection-based
+// algorithms don't work during bootstrapping.
+option optimize_for = SPEED;
+
+// The protocol compiler can output a FileDescriptorSet containing the .proto
+// files it parses.
+message FileDescriptorSet {
+  repeated FileDescriptorProto file = 1;
+}
+
+// Describes a complete .proto file.
+message FileDescriptorProto {
+  optional string name = 1;       // file name, relative to root of source tree
+  optional string package = 2;    // e.g. "foo", "foo.bar", etc.
+
+  // Names of files imported by this file.
+  repeated string dependency = 3;
+
+  // All top-level definitions in this file.
+  repeated DescriptorProto message_type = 4;
+  repeated EnumDescriptorProto enum_type = 5;
+  repeated ServiceDescriptorProto service = 6;
+  repeated FieldDescriptorProto extension = 7;
+
+  optional FileOptions options = 8;
+
+  // This field contains optional information about the original source code.
+  // You may safely remove this entire field whithout harming runtime
+  // functionality of the descriptors -- the information is needed only by
+  // development tools.
+  optional SourceCodeInfo source_code_info = 9;
+}
+
+// Describes a message type.
+message DescriptorProto {
+  optional string name = 1;
+
+  repeated FieldDescriptorProto field = 2;
+  repeated FieldDescriptorProto extension = 6;
+
+  repeated DescriptorProto nested_type = 3;
+  repeated EnumDescriptorProto enum_type = 4;
+
+  message ExtensionRange {
+    optional int32 start = 1;
+    optional int32 end = 2;
+  }
+  repeated ExtensionRange extension_range = 5;
+
+  optional MessageOptions options = 7;
+}
+
+// Describes a field within a message.
+message FieldDescriptorProto {
+  enum Type {
+    // 0 is reserved for errors.
+    // Order is weird for historical reasons.
+    TYPE_DOUBLE         = 1;
+    TYPE_FLOAT          = 2;
+    TYPE_INT64          = 3;   // Not ZigZag encoded.  Negative numbers
+                               // take 10 bytes.  Use TYPE_SINT64 if negative
+                               // values are likely.
+    TYPE_UINT64         = 4;
+    TYPE_INT32          = 5;   // Not ZigZag encoded.  Negative numbers
+                               // take 10 bytes.  Use TYPE_SINT32 if negative
+                               // values are likely.
+    TYPE_FIXED64        = 6;
+    TYPE_FIXED32        = 7;
+    TYPE_BOOL           = 8;
+    TYPE_STRING         = 9;
+    TYPE_GROUP          = 10;  // Tag-delimited aggregate.
+    TYPE_MESSAGE        = 11;  // Length-delimited aggregate.
+
+    // New in version 2.
+    TYPE_BYTES          = 12;
+    TYPE_UINT32         = 13;
+    TYPE_ENUM           = 14;
+    TYPE_SFIXED32       = 15;
+    TYPE_SFIXED64       = 16;
+    TYPE_SINT32         = 17;  // Uses ZigZag encoding.
+    TYPE_SINT64         = 18;  // Uses ZigZag encoding.
+  };
+
+  enum Label {
+    // 0 is reserved for errors
+    LABEL_OPTIONAL      = 1;
+    LABEL_REQUIRED      = 2;
+    LABEL_REPEATED      = 3;
+    // TODO(sanjay): Should we add LABEL_MAP?
+  };
+
+  optional string name = 1;
+  optional int32 number = 3;
+  optional Label label = 4;
+
+  // If type_name is set, this need not be set.  If both this and type_name
+  // are set, this must be either TYPE_ENUM or TYPE_MESSAGE.
+  optional Type type = 5;
+
+  // For message and enum types, this is the name of the type.  If the name
+  // starts with a '.', it is fully-qualified.  Otherwise, C++-like scoping
+  // rules are used to find the type (i.e. first the nested types within this
+  // message are searched, then within the parent, on up to the root
+  // namespace).
+  optional string type_name = 6;
+
+  // For extensions, this is the name of the type being extended.  It is
+  // resolved in the same manner as type_name.
+  optional string extendee = 2;
+
+  // For numeric types, contains the original text representation of the value.
+  // For booleans, "true" or "false".
+  // For strings, contains the default text contents (not escaped in any way).
+  // For bytes, contains the C escaped value.  All bytes >= 128 are escaped.
+  // TODO(kenton):  Base-64 encode?
+  optional string default_value = 7;
+
+  optional FieldOptions options = 8;
+}
+
+// Describes an enum type.
+message EnumDescriptorProto {
+  optional string name = 1;
+
+  repeated EnumValueDescriptorProto value = 2;
+
+  optional EnumOptions options = 3;
+}
+
+// Describes a value within an enum.
+message EnumValueDescriptorProto {
+  optional string name = 1;
+  optional int32 number = 2;
+
+  optional EnumValueOptions options = 3;
+}
+
+// Describes a service.
+message ServiceDescriptorProto {
+  optional string name = 1;
+  repeated MethodDescriptorProto method = 2;
+
+  optional ServiceOptions options = 3;
+}
+
+// Describes a method of a service.
+message MethodDescriptorProto {
+  optional string name = 1;
+
+  // Input and output type names.  These are resolved in the same way as
+  // FieldDescriptorProto.type_name, but must refer to a message type.
+  optional string input_type = 2;
+  optional string output_type = 3;
+
+  optional MethodOptions options = 4;
+}
+
+// ===================================================================
+// Options
+
+// Each of the definitions above may have "options" attached.  These are
+// just annotations which may cause code to be generated slightly differently
+// or may contain hints for code that manipulates protocol messages.
+//
+// Clients may define custom options as extensions of the *Options messages.
+// These extensions may not yet be known at parsing time, so the parser cannot
+// store the values in them.  Instead it stores them in a field in the *Options
+// message called uninterpreted_option. This field must have the same name
+// across all *Options messages. We then use this field to populate the
+// extensions when we build a descriptor, at which point all protos have been
+// parsed and so all extensions are known.
+//
+// Extension numbers for custom options may be chosen as follows:
+// * For options which will only be used within a single application or
+//   organization, or for experimental options, use field numbers 50000
+//   through 99999.  It is up to you to ensure that you do not use the
+//   same number for multiple options.
+// * For options which will be published and used publicly by multiple
+//   independent entities, e-mail protobuf-global-extension-registry@google.com
+//   to reserve extension numbers. Simply provide your project name (e.g.
+//   Object-C plugin) and your porject website (if available) -- there's no need
+//   to explain how you intend to use them. Usually you only need one extension
+//   number. You can declare multiple options with only one extension number by
+//   putting them in a sub-message. See the Custom Options section of the docs
+//   for examples:
+//   http://code.google.com/apis/protocolbuffers/docs/proto.html#options
+//   If this turns out to be popular, a web service will be set up
+//   to automatically assign option numbers.
+
+
+message FileOptions {
+
+  // Sets the Java package where classes generated from this .proto will be
+  // placed.  By default, the proto package is used, but this is often
+  // inappropriate because proto packages do not normally start with backwards
+  // domain names.
+  optional string java_package = 1;
+
+
+  // If set, all the classes from the .proto file are wrapped in a single
+  // outer class with the given name.  This applies to both Proto1
+  // (equivalent to the old "--one_java_file" option) and Proto2 (where
+  // a .proto always translates to a single class, but you may want to
+  // explicitly choose the class name).
+  optional string java_outer_classname = 8;
+
+  // If set true, then the Java code generator will generate a separate .java
+  // file for each top-level message, enum, and service defined in the .proto
+  // file.  Thus, these types will *not* be nested inside the outer class
+  // named by java_outer_classname.  However, the outer class will still be
+  // generated to contain the file's getDescriptor() method as well as any
+  // top-level extensions defined in the file.
+  optional bool java_multiple_files = 10 [default=false];
+
+  // If set true, then the Java code generator will generate equals() and
+  // hashCode() methods for all messages defined in the .proto file. This is
+  // purely a speed optimization, as the AbstractMessage base class includes
+  // reflection-based implementations of these methods.
+  optional bool java_generate_equals_and_hash = 20 [default=false];
+
+  // Generated classes can be optimized for speed or code size.
+  enum OptimizeMode {
+    SPEED = 1;        // Generate complete code for parsing, serialization,
+                      // etc.
+    CODE_SIZE = 2;    // Use ReflectionOps to implement these methods.
+    LITE_RUNTIME = 3; // Generate code using MessageLite and the lite runtime.
+  }
+  optional OptimizeMode optimize_for = 9 [default=SPEED];
+
+
+
+
+  // Should generic services be generated in each language?  "Generic" services
+  // are not specific to any particular RPC system.  They are generated by the
+  // main code generators in each language (without additional plugins).
+  // Generic services were the only kind of service generation supported by
+  // early versions of proto2.
+  //
+  // Generic services are now considered deprecated in favor of using plugins
+  // that generate code specific to your particular RPC system.  Therefore,
+  // these default to false.  Old code which depends on generic services should
+  // explicitly set them to true.
+  optional bool cc_generic_services = 16 [default=false];
+  optional bool java_generic_services = 17 [default=false];
+  optional bool py_generic_services = 18 [default=false];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message MessageOptions {
+  // Set true to use the old proto1 MessageSet wire format for extensions.
+  // This is provided for backwards-compatibility with the MessageSet wire
+  // format.  You should not use this for any other reason:  It's less
+  // efficient, has fewer features, and is more complicated.
+  //
+  // The message must be defined exactly as follows:
+  //   message Foo {
+  //     option message_set_wire_format = true;
+  //     extensions 4 to max;
+  //   }
+  // Note that the message cannot have any defined fields; MessageSets only
+  // have extensions.
+  //
+  // All extensions of your type must be singular messages; e.g. they cannot
+  // be int32s, enums, or repeated messages.
+  //
+  // Because this is an option, the above two restrictions are not enforced by
+  // the protocol compiler.
+  optional bool message_set_wire_format = 1 [default=false];
+
+  // Disables the generation of the standard "descriptor()" accessor, which can
+  // conflict with a field of the same name.  This is meant to make migration
+  // from proto1 easier; new code should avoid fields named "descriptor".
+  optional bool no_standard_descriptor_accessor = 2 [default=false];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message FieldOptions {
+  // The ctype option instructs the C++ code generator to use a different
+  // representation of the field than it normally would.  See the specific
+  // options below.  This option is not yet implemented in the open source
+  // release -- sorry, we'll try to include it in a future version!
+  optional CType ctype = 1 [default = STRING];
+  enum CType {
+    // Default mode.
+    STRING = 0;
+
+    CORD = 1;
+
+    STRING_PIECE = 2;
+  }
+  // The packed option can be enabled for repeated primitive fields to enable
+  // a more efficient representation on the wire. Rather than repeatedly
+  // writing the tag and type for each element, the entire array is encoded as
+  // a single length-delimited blob.
+  optional bool packed = 2;
+
+
+  // Is this field deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for accessors, or it will be completely ignored; in the very least, this
+  // is a formalization for deprecating fields.
+  optional bool deprecated = 3 [default=false];
+
+  // EXPERIMENTAL.  DO NOT USE.
+  // For "map" fields, the name of the field in the enclosed type that
+  // is the key for this map.  For example, suppose we have:
+  //   message Item {
+  //     required string name = 1;
+  //     required string value = 2;
+  //   }
+  //   message Config {
+  //     repeated Item items = 1 [experimental_map_key="name"];
+  //   }
+  // In this situation, the map key for Item will be set to "name".
+  // TODO: Fully-implement this, then remove the "experimental_" prefix.
+  optional string experimental_map_key = 9;
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message EnumOptions {
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message EnumValueOptions {
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message ServiceOptions {
+
+  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
+  //   framework.  We apologize for hoarding these numbers to ourselves, but
+  //   we were already using them long before we decided to release Protocol
+  //   Buffers.
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message MethodOptions {
+
+  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
+  //   framework.  We apologize for hoarding these numbers to ourselves, but
+  //   we were already using them long before we decided to release Protocol
+  //   Buffers.
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+// A message representing a option the parser does not recognize. This only
+// appears in options protos created by the compiler::Parser class.
+// DescriptorPool resolves these when building Descriptor objects. Therefore,
+// options protos in descriptor objects (e.g. returned by Descriptor::options(),
+// or produced by Descriptor::CopyTo()) will never have UninterpretedOptions
+// in them.
+message UninterpretedOption {
+  // The name of the uninterpreted option.  Each string represents a segment in
+  // a dot-separated name.  is_extension is true iff a segment represents an
+  // extension (denoted with parentheses in options specs in .proto files).
+  // E.g.,{ ["foo", false], ["bar.baz", true], ["qux", false] } represents
+  // "foo.(bar.baz).qux".
+  message NamePart {
+    required string name_part = 1;
+    required bool is_extension = 2;
+  }
+  repeated NamePart name = 2;
+
+  // The value of the uninterpreted option, in whatever type the tokenizer
+  // identified it as during parsing. Exactly one of these should be set.
+  optional string identifier_value = 3;
+  optional uint64 positive_int_value = 4;
+  optional int64 negative_int_value = 5;
+  optional double double_value = 6;
+  optional bytes string_value = 7;
+  optional string aggregate_value = 8;
+}
+
+// ===================================================================
+// Optional source code info
+
+// Encapsulates information about the original source file from which a
+// FileDescriptorProto was generated.
+message SourceCodeInfo {
+  // A Location identifies a piece of source code in a .proto file which
+  // corresponds to a particular definition.  This information is intended
+  // to be useful to IDEs, code indexers, documentation generators, and similar
+  // tools.
+  //
+  // For example, say we have a file like:
+  //   message Foo {
+  //     optional string foo = 1;
+  //   }
+  // Let's look at just the field definition:
+  //   optional string foo = 1;
+  //   ^       ^^     ^^  ^  ^^^
+  //   a       bc     de  f  ghi
+  // We have the following locations:
+  //   span   path               represents
+  //   [a,i)  [ 4, 0, 2, 0 ]     The whole field definition.
+  //   [a,b)  [ 4, 0, 2, 0, 4 ]  The label (optional).
+  //   [c,d)  [ 4, 0, 2, 0, 5 ]  The type (string).
+  //   [e,f)  [ 4, 0, 2, 0, 1 ]  The name (foo).
+  //   [g,h)  [ 4, 0, 2, 0, 3 ]  The number (1).
+  //
+  // Notes:
+  // - A location may refer to a repeated field itself (i.e. not to any
+  //   particular index within it).  This is used whenever a set of elements are
+  //   logically enclosed in a single code segment.  For example, an entire
+  //   extend block (possibly containing multiple extension definitions) will
+  //   have an outer location whose path refers to the "extensions" repeated
+  //   field without an index.
+  // - Multiple locations may have the same path.  This happens when a single
+  //   logical declaration is spread out across multiple places.  The most
+  //   obvious example is the "extend" block again -- there may be multiple
+  //   extend blocks in the same scope, each of which will have the same path.
+  // - A location's span is not always a subset of its parent's span.  For
+  //   example, the "extendee" of an extension declaration appears at the
+  //   beginning of the "extend" block and is shared by all extensions within
+  //   the block.
+  // - Just because a location's span is a subset of some other location's span
+  //   does not mean that it is a descendent.  For example, a "group" defines
+  //   both a type and a field in a single declaration.  Thus, the locations
+  //   corresponding to the type and field and their components will overlap.
+  // - Code which tries to interpret locations should probably be designed to
+  //   ignore those that it doesn't understand, as more types of locations could
+  //   be recorded in the future.
+  repeated Location location = 1;
+  message Location {
+    // Identifies which part of the FileDescriptorProto was defined at this
+    // location.
+    //
+    // Each element is a field number or an index.  They form a path from
+    // the root FileDescriptorProto to the place where the definition.  For
+    // example, this path:
+    //   [ 4, 3, 2, 7, 1 ]
+    // refers to:
+    //   file.message_type(3)  // 4, 3
+    //       .field(7)         // 2, 7
+    //       .name()           // 1
+    // This is because FileDescriptorProto.message_type has field number 4:
+    //   repeated DescriptorProto message_type = 4;
+    // and DescriptorProto.field has field number 2:
+    //   repeated FieldDescriptorProto field = 2;
+    // and FieldDescriptorProto.name has field number 1:
+    //   optional string name = 1;
+    //
+    // Thus, the above path gives the location of a field name.  If we removed
+    // the last element:
+    //   [ 4, 3, 2, 7 ]
+    // this path refers to the whole field declaration (from the beginning
+    // of the label to the terminating semicolon).
+    repeated int32 path = 1 [packed=true];
+
+    // Always has exactly three or four elements: start line, start column,
+    // end line (optional, otherwise assumed same as start line), end column.
+    // These are packed into a single field for efficiency.  Note that line
+    // and column numbers are zero-based -- typically you will want to add
+    // 1 to each before displaying to a user.
+    repeated int32 span = 2 [packed=true];
+
+    // TODO(kenton):  Record comments appearing before and after the
+    // declaration.
+  }
+}
diff --git a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/Descriptor.java b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/Descriptor.java
index 50d770c..059ebb2 100644
--- a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/Descriptor.java
+++ b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/Descriptor.java
@@ -9,23 +9,23 @@
 package com.google.eclipse.protobuf.scoping;
 
 import static com.google.eclipse.protobuf.scoping.OptionType.*;
+import static com.google.eclipse.protobuf.util.Closeables.close;
 import static java.util.Collections.unmodifiableCollection;
 import static org.eclipse.emf.common.util.URI.createURI;
 import static org.eclipse.xtext.EcoreUtil2.*;
 import static org.eclipse.xtext.util.CancelIndicator.NullImpl;
 
-import java.io.*;
-import java.util.*;
-
-import org.eclipse.xtext.parser.IParseResult;
-import org.eclipse.xtext.parser.IParser;
-import org.eclipse.xtext.resource.XtextResource;
-import org.eclipse.xtext.util.StringInputStream;
-
 import com.google.eclipse.protobuf.protobuf.*;
 import com.google.eclipse.protobuf.protobuf.Enum;
 import com.google.inject.Inject;
 
+import org.eclipse.xtext.parser.*;
+import org.eclipse.xtext.resource.XtextResource;
+
+import java.io.*;
+import java.net.URL;
+import java.util.*;
+
 /**
  * Contains the elements from descriptor.proto (provided with protobuf's library.)
  *
@@ -33,28 +33,29 @@
  */
 public class Descriptor {
 
-  private Protobuf root;
+  private static final String DESCRIPTOR_URI = "platform:/plugin/com.google.eclipse.protobuf/descriptor.proto";
 
   private final Map<OptionType, Map<String, Property>> options = new HashMap<OptionType, Map<String, Property>>();
    
+  private Protobuf root;
   private Enum optimizedMode;
   private Enum cType;
 
-  /**
-   * Creates a new </code>{@link Descriptor}</code>.
-   * @param parser the grammar parser.
-   */
   @Inject public Descriptor(IParser parser) {
     addOptionTypes();
+    InputStreamReader reader = null;
     try {
-      XtextResource resource = new XtextResource(createURI("descriptor.proto"));
-      IParseResult result = parser.parse(new InputStreamReader(globalScopeContents(), "UTF-8"));
+      XtextResource resource = new XtextResource(createURI(DESCRIPTOR_URI));
+      reader = new InputStreamReader(globalScopeContents(), "UTF-8");
+      IParseResult result = parser.parse(reader);
       root = (Protobuf) result.getRootASTElement();
       resource.getContents().add(root);
       resolveLazyCrossReferences(resource, NullImpl);
       initContents();
     } catch (IOException e) {
-      throw new IllegalStateException("Unable to parse global scope", e);
+      throw new IllegalStateException("Unable to parse descriptor.proto", e);
+    } finally {
+      close(reader);
     }
   }
 
@@ -63,45 +64,9 @@
       options.put(type, new LinkedHashMap<String, Property>());
   }
   
-  private static InputStream globalScopeContents() {
-    return new StringInputStream(descriptorContents());
-  }
-
-  private static String descriptorContents() {
-    StringBuilder proto = new StringBuilder();
-    proto.append("message FileOptions {")
-         .append("  optional string java_package = 1;")
-         .append("  optional string java_outer_classname = 8;")
-         .append("  optional bool java_multiple_files = 10 [default=false];")
-         .append("  optional bool java_generate_equals_and_hash = 20 [default=false];")
-         .append("  enum OptimizeMode {")
-         .append("    SPEED = 1;")
-         .append("    CODE_SIZE = 2;")
-         .append("    LITE_RUNTIME = 3;")
-         .append("  }")
-         .append("  optional OptimizeMode optimize_for = 9 [default=SPEED];")
-         .append("  optional bool cc_generic_services = 16 [default=false];")
-         .append("  optional bool java_generic_services = 17 [default=false];")
-         .append("  optional bool py_generic_services = 18 [default=false];")
-         .append("  extensions 1000 to max;")
-         .append("}")
-         .append("message MessageOptions {")
-         .append("  optional bool message_set_wire_format = 1 [default=false];")
-         .append("  optional bool no_standard_descriptor_accessor = 2 [default=false];")
-         .append("  extensions 1000 to max;")
-         .append("}")
-         .append("message FieldOptions {")
-         .append("  optional CType ctype = 1 [default = STRING];")
-         .append("  enum CType {")
-         .append("    STRING = 0;")
-         .append("    CORD = 1;")
-         .append("    STRING_PIECE = 2;")
-         .append("  }")
-         .append("  optional bool packed = 2;")
-         .append("  optional bool deprecated = 3 [default=false];")
-         .append("  extensions 1000 to max;")
-         .append("}");
-    return proto.toString();
+  private static InputStream globalScopeContents() throws IOException {
+    URL url = new URL(DESCRIPTOR_URI);
+    return url.openConnection().getInputStream();
   }
 
   private void initContents() {
@@ -192,35 +157,16 @@
   }
 
   /**
-   * Returns the {@code enum} "OptimizeMode" (defined in {@code google/protobuf/descriptor.proto}. More details can be
-   * found <a href=http://code.google.com/apis/protocolbuffers/docs/proto.html#options" target="_blank">here</a>.)
-   * @return the {@code enum} "OptimizeMode."
-   */
-  public Enum optimizedMode() {
-    return optimizedMode;
-  }
-
-  /**
-   * Indicates whether the given option is the "optimize_for" one (defined in {@code google/protobuf/descriptor.proto}.
-   * More details can be found
-   * <a href=http://code.google.com/apis/protocolbuffers/docs/proto.html#options" target="_blank">here</a>.)
-   * @param option the given option.
-   * @return {@code true} if the given option is the "optimize_for" one, {@code false} otherwise.
-   */
-  public boolean isOptimizeForOption(Option option) {
-    if (option == null) return false;
-    return "optimize_for".equals(option.getName());
-  }
-
-  /**
-   * Looks up a file-level option per name. File-level options are defined in {@code google/protobuf/descriptor.proto}
+   * Looks up an option per name, as defined in {@code google/protobuf/descriptor.proto}
    * (more details can be found <a
    * href=http://code.google.com/apis/protocolbuffers/docs/proto.html#options" target="_blank">here</a>.)
    * @param name the name of the option to look for.
    * @return the option whose name matches the given one or {@code null} if a matching option is not found.
    */
-  public Property lookupFileOption(String name) {
-    return lookupOption(FILE, name);
+  public Property lookupOption(String name) {
+    Property p = lookupOption(FILE, name);
+    if (p == null) lookupOption(MESSAGE, name);
+    return p;
   }
 
   /**
@@ -234,17 +180,6 @@
   }
 
   /**
-   * Looks up a message-level option per name. Message-level options are defined in 
-   * {@code google/protobuf/descriptor.proto} (more details can be found <a
-   * href=http://code.google.com/apis/protocolbuffers/docs/proto.html#options" target="_blank">here</a>.)
-   * @param name the name of the option to look for.
-   * @return the option whose name matches the given one or {@code null} if a matching option is not found.
-   */
-  public Property lookupMessageOption(String name) {
-    return lookupOption(MESSAGE, name);
-  }
-
-  /**
    * Returns all the field-level options available. These are the options defined in
    * {@code google/protobuf/descriptor.proto} (more details can be found
    * <a href=http://code.google.com/apis/protocolbuffers/docs/proto.html#options" target="_blank">here</a>.)
@@ -274,23 +209,36 @@
   }
 
   /**
-   * Indicates whether the given option is the "ctype" one (defined in {@code google/protobuf/descriptor.proto}.
-   * More details can be found
-   * <a href=http://code.google.com/apis/protocolbuffers/docs/proto.html#options" target="_blank">here</a>.)
+   * Returns the enum type of the given option, only if the given option is defined in 
+   * {@code google/protobuf/descriptor.proto} and its type an enum (more details can be found <a
+   * href=http://code.google.com/apis/protocolbuffers/docs/proto.html#options" target="_blank">here</a>.)
    * @param option the given option.
-   * @return {@code true} if the given option is the "ctype" one, {@code false} otherwise.
+   * @return the enum type of the given option or {@code null} if the type of the given option is not enum.
    */
-  public boolean isCTypeOption(FieldOption option) {
+  public Enum enumTypeOf(Option option) {
+    if (isOptimizeForOption(option)) return optimizedMode;
+    return null;
+  }
+
+  private boolean isOptimizeForOption(Option option) {
+    if (option == null) return false;
+    return "optimize_for".equals(option.getName());
+  }
+
+  /**
+   * Returns the enum type of the given option, only if the given option is defined in 
+   * {@code google/protobuf/descriptor.proto} and its type an enum (more details can be found <a
+   * href=http://code.google.com/apis/protocolbuffers/docs/proto.html#options" target="_blank">here</a>.)
+   * @param option the given option.
+   * @return the enum type of the given option or {@code null} if the type of the given option is not enum.
+   */
+  public Enum enumTypeOf(FieldOption option) {
+    if (isCTypeOption(option)) return cType;
+    return null;
+  }
+
+  private boolean isCTypeOption(FieldOption option) {
     if (option == null) return false;
     return "ctype".equals(option.getName());
   }
-  
-  /**
-   * Returns the {@code enum} "CType" (defined in {@code google/protobuf/descriptor.proto}. More details can be
-   * found <a href=http://code.google.com/apis/protocolbuffers/docs/proto.html#options" target="_blank">here</a>.)
-   * @return the {@code enum} "CType."
-   */
-  public Enum cType() {
-    return cType;
-  }
 }
diff --git a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/DescriptorProvider.java b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/DescriptorProvider.java
index 2ff1323..dc481ea 100644
--- a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/DescriptorProvider.java
+++ b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/DescriptorProvider.java
@@ -8,10 +8,10 @@
  */
 package com.google.eclipse.protobuf.scoping;
 
-import org.eclipse.xtext.parser.IParser;
-
 import com.google.inject.*;
 
+import org.eclipse.xtext.parser.IParser;
+
 /**
  * Provider of a singleton instance of <code>{@link Descriptor}</code>.
  *
diff --git a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/ProtobufScopeProvider.java b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/ProtobufScopeProvider.java
index 0d09afb..963a962 100644
--- a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/ProtobufScopeProvider.java
+++ b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/ProtobufScopeProvider.java
@@ -122,7 +122,6 @@
     try {
       return resourceSet.getResource(importUri, true);
     } catch (Throwable t) {
-      t.printStackTrace();
       return null;
     }
   }
@@ -161,15 +160,15 @@
       Enum enumType = finder.enumTypeOf((Property) container);
       if (enumType != null) return scopeForLiterals(enumType);
     }
+    Enum enumType = enumTypeOfOption(container);
+    if (enumType != null) return scopeForLiterals(enumType);
+    return null;
+  }
+
+  private Enum enumTypeOfOption(EObject mayBeOption) {
     Descriptor descriptor = descriptorProvider.get();
-    if (container instanceof Option && descriptor.isOptimizeForOption((Option) container)) {
-      Enum optimizedMode = descriptor.optimizedMode();
-      return scopeForLiterals(optimizedMode);
-    }
-    if (container instanceof FieldOption && descriptor.isCTypeOption((FieldOption) container)) {
-      Enum cType = descriptor.cType();
-      return scopeForLiterals(cType);
-    }
+    if (mayBeOption instanceof Option) return descriptor.enumTypeOf((Option) mayBeOption);
+    if (mayBeOption instanceof FieldOption) return descriptor.enumTypeOf((FieldOption) mayBeOption);
     return null;
   }
 
diff --git a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/util/Closeables.java b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/util/Closeables.java
new file mode 100644
index 0000000..7fdb025
--- /dev/null
+++ b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/util/Closeables.java
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2011 Google Inc. All rights reserved. This program and the accompanying materials are made available
+ * under the terms of the Eclipse Public License v1.0 which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+package com.google.eclipse.protobuf.util;
+
+import java.io.*;
+
+/**
+ * Utility methods related to <code>{@link Closeable}</code>.
+ * 
+ * @author alruiz@google.com (Alex Ruiz)
+ */
+public class Closeables {
+  
+  public static boolean close(Closeable c) {
+    if (c == null) return false;
+    try {
+      c.close();
+    } catch (IOException ignored) {}
+    return true;
+  }
+
+  private Closeables() {}
+}