HeaderDoc support in the library and generated sources

- Convert most of the core library headers over to HeaderDoc format.
- Switch the generated comments over to HeaderDoc.
- Create GPBCodedOutputStream_PackagePrivate and move some things into there
  that should be more internal.

1 files changed, 132 insertions, 129 deletions

diff --git a/objectivec/google/protobuf/FieldMask.pbobjc.h b/objectivec/google/protobuf/FieldMask.pbobjc.h
index f4bc2653..f861a986 100644
--- a/objectivec/google/protobuf/FieldMask.pbobjc.h
+++ b/objectivec/google/protobuf/FieldMask.pbobjc.h
@@ -15,13 +15,15 @@ NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark - GPBFieldMaskRoot
 
+/// Exposes the extension registry for this file.
+///
+/// The base class provides:
+/// @code
+///   + (GPBExtensionRegistry *)extensionRegistry;
+/// @endcode
+/// which is a @c GPBExtensionRegistry that includes all the extensions defined by
+/// this file and all files that it depends on.
 @interface GPBFieldMaskRoot : GPBRootObject
-
-// The base class provides:
-//   + (GPBExtensionRegistry *)extensionRegistry;
-// which is an GPBExtensionRegistry that includes all the extensions defined by
-// this file and all files that it depends on.
-
 @end
 
 #pragma mark - GPBFieldMask
@@ -30,132 +32,133 @@ typedef GPB_ENUM(GPBFieldMask_FieldNumber) {
   GPBFieldMask_FieldNumber_PathsArray = 1,
 };
 
-// `FieldMask` represents a set of symbolic field paths, for example:
-//
-//     paths: "f.a"
-//     paths: "f.b.d"
-//
-// Here `f` represents a field in some root message, `a` and `b`
-// fields in the message found in `f`, and `d` a field found in the
-// message in `f.b`.
-//
-// Field masks are used to specify a subset of fields that should be
-// returned by a get operation or modified by an update operation.
-// Field masks also have a custom JSON encoding (see below).
-//
-// # Field Masks in Projections
-//
-// When used in the context of a projection, a response message or
-// sub-message is filtered by the API to only contain those fields as
-// specified in the mask. For example, if the mask in the previous
-// example is applied to a response message as follows:
-//
-//     f {
-//       a : 22
-//       b {
-//         d : 1
-//         x : 2
-//       }
-//       y : 13
-//     }
-//     z: 8
-//
-// The result will not contain specific values for fields x,y and z
-// (their value will be set to the default, and omitted in proto text
-// output):
-//
-//
-//     f {
-//       a : 22
-//       b {
-//         d : 1
-//       }
-//     }
-//
-// A repeated field is not allowed except at the last position of a
-// field mask.
-//
-// If a FieldMask object is not present in a get operation, the
-// operation applies to all fields (as if a FieldMask of all fields
-// had been specified).
-//
-// Note that a field mask does not necessarily applies to the
-// top-level response message. In case of a REST get operation, the
-// field mask applies directly to the response, but in case of a REST
-// list operation, the mask instead applies to each individual message
-// in the returned resource list. In case of a REST custom method,
-// other definitions may be used. Where the mask applies will be
-// clearly documented together with its declaration in the API.  In
-// any case, the effect on the returned resource/resources is required
-// behavior for APIs.
-//
-// # Field Masks in Update Operations
-//
-// A field mask in update operations specifies which fields of the
-// targeted resource are going to be updated. The API is required
-// to only change the values of the fields as specified in the mask
-// and leave the others untouched. If a resource is passed in to
-// describe the updated values, the API ignores the values of all
-// fields not covered by the mask.
-//
-// In order to reset a field's value to the default, the field must
-// be in the mask and set to the default value in the provided resource.
-// Hence, in order to reset all fields of a resource, provide a default
-// instance of the resource and set all fields in the mask, or do
-// not provide a mask as described below.
-//
-// If a field mask is not present on update, the operation applies to
-// all fields (as if a field mask of all fields has been specified).
-// Note that in the presence of schema evolution, this may mean that
-// fields the client does not know and has therefore not filled into
-// the request will be reset to their default. If this is unwanted
-// behavior, a specific service may require a client to always specify
-// a field mask, producing an error if not.
-//
-// As with get operations, the location of the resource which
-// describes the updated values in the request message depends on the
-// operation kind. In any case, the effect of the field mask is
-// required to be honored by the API.
-//
-// ## Considerations for HTTP REST
-//
-// The HTTP kind of an update operation which uses a field mask must
-// be set to PATCH instead of PUT in order to satisfy HTTP semantics
-// (PUT must only be used for full updates).
-//
-// # JSON Encoding of Field Masks
-//
-// In JSON, a field mask is encoded as a single string where paths are
-// separated by a comma. Fields name in each path are converted
-// to/from lower-camel naming conventions.
-//
-// As an example, consider the following message declarations:
-//
-//     message Profile {
-//       User user = 1;
-//       Photo photo = 2;
-//     }
-//     message User {
-//       string display_name = 1;
-//       string address = 2;
-//     }
-//
-// In proto a field mask for `Profile` may look as such:
-//
-//     mask {
-//       paths: "user.display_name"
-//       paths: "photo"
-//     }
-//
-// In JSON, the same mask is represented as below:
-//
-//     {
-//       mask: "user.displayName,photo"
-//     }
+/// `FieldMask` represents a set of symbolic field paths, for example:
+///
+///     paths: "f.a"
+///     paths: "f.b.d"
+///
+/// Here `f` represents a field in some root message, `a` and `b`
+/// fields in the message found in `f`, and `d` a field found in the
+/// message in `f.b`.
+///
+/// Field masks are used to specify a subset of fields that should be
+/// returned by a get operation or modified by an update operation.
+/// Field masks also have a custom JSON encoding (see below).
+///
+/// # Field Masks in Projections
+///
+/// When used in the context of a projection, a response message or
+/// sub-message is filtered by the API to only contain those fields as
+/// specified in the mask. For example, if the mask in the previous
+/// example is applied to a response message as follows:
+///
+///     f {
+///       a : 22
+///       b {
+///         d : 1
+///         x : 2
+///       }
+///       y : 13
+///     }
+///     z: 8
+///
+/// The result will not contain specific values for fields x,y and z
+/// (their value will be set to the default, and omitted in proto text
+/// output):
+///
+///
+///     f {
+///       a : 22
+///       b {
+///         d : 1
+///       }
+///     }
+///
+/// A repeated field is not allowed except at the last position of a
+/// field mask.
+///
+/// If a FieldMask object is not present in a get operation, the
+/// operation applies to all fields (as if a FieldMask of all fields
+/// had been specified).
+///
+/// Note that a field mask does not necessarily applies to the
+/// top-level response message. In case of a REST get operation, the
+/// field mask applies directly to the response, but in case of a REST
+/// list operation, the mask instead applies to each individual message
+/// in the returned resource list. In case of a REST custom method,
+/// other definitions may be used. Where the mask applies will be
+/// clearly documented together with its declaration in the API.  In
+/// any case, the effect on the returned resource/resources is required
+/// behavior for APIs.
+///
+/// # Field Masks in Update Operations
+///
+/// A field mask in update operations specifies which fields of the
+/// targeted resource are going to be updated. The API is required
+/// to only change the values of the fields as specified in the mask
+/// and leave the others untouched. If a resource is passed in to
+/// describe the updated values, the API ignores the values of all
+/// fields not covered by the mask.
+///
+/// In order to reset a field's value to the default, the field must
+/// be in the mask and set to the default value in the provided resource.
+/// Hence, in order to reset all fields of a resource, provide a default
+/// instance of the resource and set all fields in the mask, or do
+/// not provide a mask as described below.
+///
+/// If a field mask is not present on update, the operation applies to
+/// all fields (as if a field mask of all fields has been specified).
+/// Note that in the presence of schema evolution, this may mean that
+/// fields the client does not know and has therefore not filled into
+/// the request will be reset to their default. If this is unwanted
+/// behavior, a specific service may require a client to always specify
+/// a field mask, producing an error if not.
+///
+/// As with get operations, the location of the resource which
+/// describes the updated values in the request message depends on the
+/// operation kind. In any case, the effect of the field mask is
+/// required to be honored by the API.
+///
+/// ## Considerations for HTTP REST
+///
+/// The HTTP kind of an update operation which uses a field mask must
+/// be set to PATCH instead of PUT in order to satisfy HTTP semantics
+/// (PUT must only be used for full updates).
+///
+/// # JSON Encoding of Field Masks
+///
+/// In JSON, a field mask is encoded as a single string where paths are
+/// separated by a comma. Fields name in each path are converted
+/// to/from lower-camel naming conventions.
+///
+/// As an example, consider the following message declarations:
+///
+///     message Profile {
+///       User user = 1;
+///       Photo photo = 2;
+///     }
+///     message User {
+///       string display_name = 1;
+///       string address = 2;
+///     }
+///
+/// In proto a field mask for `Profile` may look as such:
+///
+///     mask {
+///       paths: "user.display_name"
+///       paths: "photo"
+///     }
+///
+/// In JSON, the same mask is represented as below:
+///
+///     {
+///       mask: "user.displayName,photo"
+///     }
 @interface GPBFieldMask : GPBMessage
 
-// The set of field mask paths.
+/// The set of field mask paths.
 @property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<NSString*> *pathsArray;
+/// The number of items in @c pathsArray without causing the array to be created.
 @property(nonatomic, readonly) NSUInteger pathsArray_Count;
 
 @end