Down-integrate from internal code base.

1 files changed, 34 insertions, 17 deletions

diff --git a/src/google/protobuf/descriptor.proto b/src/google/protobuf/descriptor.proto
index a753601f..f30f4df5 100644
--- a/src/google/protobuf/descriptor.proto
+++ b/src/google/protobuf/descriptor.proto
@@ -37,6 +37,7 @@
 // without any other information (e.g. without reading its imports).
 
 
+syntax = "proto2";
 
 package google.protobuf;
 option java_package = "com.google.protobuf";
@@ -74,10 +75,14 @@ message FileDescriptorProto {
   optional FileOptions options = 8;
 
   // This field contains optional information about the original source code.
-  // You may safely remove this entire field whithout harming runtime
+  // You may safely remove this entire field without harming runtime
   // functionality of the descriptors -- the information is needed only by
   // development tools.
   optional SourceCodeInfo source_code_info = 9;
+
+  // The syntax of the proto file.
+  // The supported values are "proto2" and "proto3".
+  optional string syntax = 12;
 }
 
 // Describes a message type.
@@ -306,7 +311,10 @@ message FileOptions {
   optional OptimizeMode optimize_for = 9 [default=SPEED];
 
   // Sets the Go package where structs generated from this .proto will be
-  // placed.  There is no default.
+  // placed. If omitted, the Go package will be derived from the following:
+  //   - The basename of the package import path, if provided.
+  //   - Otherwise, the package statement in the .proto file, if present.
+  //   - Otherwise, the basename of the .proto file, without extension.
   optional string go_package = 11;
 
 
@@ -315,7 +323,7 @@ message FileOptions {
   // 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.
+  // early versions of google.protobuf.
   //
   // Generic services are now considered deprecated in favor of using plugins
   // that generate code specific to your particular RPC system.  Therefore,
@@ -371,6 +379,29 @@ message MessageOptions {
   // this is a formalization for deprecating messages.
   optional bool deprecated = 3 [default=false];
 
+  // Whether the message is an automatically generated map entry type for the
+  // maps field.
+  //
+  // For maps fields:
+  //     map<KeyType, ValueType> map_field = 1;
+  // The parsed descriptor looks like:
+  //     message MapFieldEntry {
+  //         option map_entry = true;
+  //         optional KeyType key = 1;
+  //         optional ValueType value = 2;
+  //     }
+  //     repeated MapFieldEntry map_field = 1;
+  //
+  // Implementations may choose not to generate the map_entry=true message, but
+  // use a native map in the target language to hold the keys and values.
+  // The reflection APIs in such implementions still need to work as
+  // if the field is a repeated message field.
+  //
+  // NOTE: Do not set the option in .proto files. Always use the maps syntax
+  // instead. The option should only be implicitly set by the proto compiler
+  // parser.
+  optional bool map_entry = 7;
+
   // The parser stores options it doesn't recognize here. See above.
   repeated UninterpretedOption uninterpreted_option = 999;
 
@@ -436,20 +467,6 @@ message FieldOptions {
   // 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;
-
   // For Google-internal migration only. Do not use.
   optional bool weak = 10 [default=false];