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, 141 insertions, 124 deletions

diff --git a/objectivec/google/protobuf/Api.pbobjc.h b/objectivec/google/protobuf/Api.pbobjc.h
index 8d82b15f..271a166f 100644
--- a/objectivec/google/protobuf/Api.pbobjc.h
+++ b/objectivec/google/protobuf/Api.pbobjc.h
@@ -21,13 +21,15 @@ NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark - GPBApiRoot
 
+/// 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 GPBApiRoot : 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 - GPBApi
@@ -42,58 +44,67 @@ typedef GPB_ENUM(GPBApi_FieldNumber) {
   GPBApi_FieldNumber_Syntax = 7,
 };
 
-// Api is a light-weight descriptor for a protocol buffer service.
+/// Api is a light-weight descriptor for a protocol buffer service.
 @interface GPBApi : GPBMessage
 
-// The fully qualified name of this api, including package name
-// followed by the api's simple name.
+/// The fully qualified name of this api, including package name
+/// followed by the api's simple name.
 @property(nonatomic, readwrite, copy, null_resettable) NSString *name;
 
-// The methods of this api, in unspecified order.
+/// The methods of this api, in unspecified order.
 @property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBMethod*> *methodsArray;
+/// The number of items in @c methodsArray without causing the array to be created.
 @property(nonatomic, readonly) NSUInteger methodsArray_Count;
 
-// Any metadata attached to the API.
+/// Any metadata attached to the API.
 @property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBOption*> *optionsArray;
+/// The number of items in @c optionsArray without causing the array to be created.
 @property(nonatomic, readonly) NSUInteger optionsArray_Count;
 
-// A version string for this api. If specified, must have the form
-// `major-version.minor-version`, as in `1.10`. If the minor version
-// is omitted, it defaults to zero. If the entire version field is
-// empty, the major version is derived from the package name, as
-// outlined below. If the field is not empty, the version in the
-// package name will be verified to be consistent with what is
-// provided here.
-//
-// The versioning schema uses [semantic
-// versioning](http://semver.org) where the major version number
-// indicates a breaking change and the minor version an additive,
-// non-breaking change. Both version numbers are signals to users
-// what to expect from different versions, and should be carefully
-// chosen based on the product plan.
-//
-// The major version is also reflected in the package name of the
-// API, which must end in `v<major-version>`, as in
-// `google.feature.v1`. For major versions 0 and 1, the suffix can
-// be omitted. Zero major versions must only be used for
-// experimental, none-GA apis.
+/// A version string for this api. If specified, must have the form
+/// `major-version.minor-version`, as in `1.10`. If the minor version
+/// is omitted, it defaults to zero. If the entire version field is
+/// empty, the major version is derived from the package name, as
+/// outlined below. If the field is not empty, the version in the
+/// package name will be verified to be consistent with what is
+/// provided here.
+///
+/// The versioning schema uses [semantic
+/// versioning](http://semver.org) where the major version number
+/// indicates a breaking change and the minor version an additive,
+/// non-breaking change. Both version numbers are signals to users
+/// what to expect from different versions, and should be carefully
+/// chosen based on the product plan.
+///
+/// The major version is also reflected in the package name of the
+/// API, which must end in `v<major-version>`, as in
+/// `google.feature.v1`. For major versions 0 and 1, the suffix can
+/// be omitted. Zero major versions must only be used for
+/// experimental, none-GA apis.
 @property(nonatomic, readwrite, copy, null_resettable) NSString *version;
 
-// Source context for the protocol buffer service represented by this
-// message.
-@property(nonatomic, readwrite) BOOL hasSourceContext;
+/// Source context for the protocol buffer service represented by this
+/// message.
 @property(nonatomic, readwrite, strong, null_resettable) GPBSourceContext *sourceContext;
+/// Test to see if @c sourceContext has been set.
+@property(nonatomic, readwrite) BOOL hasSourceContext;
 
-// Included APIs. See [Mixin][].
+/// Included APIs. See [Mixin][].
 @property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBMixin*> *mixinsArray;
+/// The number of items in @c mixinsArray without causing the array to be created.
 @property(nonatomic, readonly) NSUInteger mixinsArray_Count;
 
-// The source syntax of the service.
+/// The source syntax of the service.
 @property(nonatomic, readwrite) enum GPBSyntax syntax;
 
 @end
 
+/// Fetches the raw value of a @c GPBApi's @c syntax property, even
+/// if the value was not defined by the enum at the time the code was generated.
 int32_t GPBApi_Syntax_RawValue(GPBApi *message);
+/// Sets the raw value of an @c GPBApi's @c syntax property, allowing
+/// it to be set to a value that was not defined by the enum at the time the code
+/// was generated.
 void SetGPBApi_Syntax_RawValue(GPBApi *message, int32_t value);
 
 #pragma mark - GPBMethod
@@ -108,34 +119,40 @@ typedef GPB_ENUM(GPBMethod_FieldNumber) {
   GPBMethod_FieldNumber_Syntax = 7,
 };
 
-// Method represents a method of an api.
+/// Method represents a method of an api.
 @interface GPBMethod : GPBMessage
 
-// The simple name of this method.
+/// The simple name of this method.
 @property(nonatomic, readwrite, copy, null_resettable) NSString *name;
 
-// A URL of the input message type.
+/// A URL of the input message type.
 @property(nonatomic, readwrite, copy, null_resettable) NSString *requestTypeURL;
 
-// If true, the request is streamed.
+/// If true, the request is streamed.
 @property(nonatomic, readwrite) BOOL requestStreaming;
 
-// The URL of the output message type.
+/// The URL of the output message type.
 @property(nonatomic, readwrite, copy, null_resettable) NSString *responseTypeURL;
 
-// If true, the response is streamed.
+/// If true, the response is streamed.
 @property(nonatomic, readwrite) BOOL responseStreaming;
 
-// Any metadata attached to the method.
+/// Any metadata attached to the method.
 @property(nonatomic, readwrite, strong, null_resettable) NSMutableArray<GPBOption*> *optionsArray;
+/// The number of items in @c optionsArray without causing the array to be created.
 @property(nonatomic, readonly) NSUInteger optionsArray_Count;
 
-// The source syntax of this method.
+/// The source syntax of this method.
 @property(nonatomic, readwrite) enum GPBSyntax syntax;
 
 @end
 
+/// Fetches the raw value of a @c GPBMethod's @c syntax property, even
+/// if the value was not defined by the enum at the time the code was generated.
 int32_t GPBMethod_Syntax_RawValue(GPBMethod *message);
+/// Sets the raw value of an @c GPBMethod's @c syntax property, allowing
+/// it to be set to a value that was not defined by the enum at the time the code
+/// was generated.
 void SetGPBMethod_Syntax_RawValue(GPBMethod *message, int32_t value);
 
 #pragma mark - GPBMixin
@@ -145,90 +162,90 @@ typedef GPB_ENUM(GPBMixin_FieldNumber) {
   GPBMixin_FieldNumber_Root = 2,
 };
 
-// Declares an API to be included in this API. The including API must
-// redeclare all the methods from the included API, but documentation
-// and options are inherited as follows:
-//
-// - If after comment and whitespace stripping, the documentation
-//   string of the redeclared method is empty, it will be inherited
-//   from the original method.
-//
-// - Each annotation belonging to the service config (http,
-//   visibility) which is not set in the redeclared method will be
-//   inherited.
-//
-// - If an http annotation is inherited, the path pattern will be
-//   modified as follows. Any version prefix will be replaced by the
-//   version of the including API plus the [root][] path if specified.
-//
-// Example of a simple mixin:
-//
-//     package google.acl.v1;
-//     service AccessControl {
-//       // Get the underlying ACL object.
-//       rpc GetAcl(GetAclRequest) returns (Acl) {
-//         option (google.api.http).get = "/v1/{resource=**}:getAcl";
-//       }
-//     }
-//
-//     package google.storage.v2;
-//     service Storage {
-//       rpc GetAcl(GetAclRequest) returns (Acl);
-//
-//       // Get a data record.
-//       rpc GetData(GetDataRequest) returns (Data) {
-//         option (google.api.http).get = "/v2/{resource=**}";
-//       }
-//     }
-//
-// Example of a mixin configuration:
-//
-//     apis:
-//     - name: google.storage.v2.Storage
-//       mixins:
-//       - name: google.acl.v1.AccessControl
-//
-// The mixin construct implies that all methods in `AccessControl` are
-// also declared with same name and request/response types in
-// `Storage`. A documentation generator or annotation processor will
-// see the effective `Storage.GetAcl` method after inherting
-// documentation and annotations as follows:
-//
-//     service Storage {
-//       // Get the underlying ACL object.
-//       rpc GetAcl(GetAclRequest) returns (Acl) {
-//         option (google.api.http).get = "/v2/{resource=**}:getAcl";
-//       }
-//       ...
-//     }
-//
-// Note how the version in the path pattern changed from `v1` to `v2`.
-//
-// If the `root` field in the mixin is specified, it should be a
-// relative path under which inherited HTTP paths are placed. Example:
-//
-//     apis:
-//     - name: google.storage.v2.Storage
-//       mixins:
-//       - name: google.acl.v1.AccessControl
-//         root: acls
-//
-// This implies the following inherited HTTP annotation:
-//
-//     service Storage {
-//       // Get the underlying ACL object.
-//       rpc GetAcl(GetAclRequest) returns (Acl) {
-//         option (google.api.http).get = "/v2/acls/{resource=**}:getAcl";
-//       }
-//       ...
-//     }
+/// Declares an API to be included in this API. The including API must
+/// redeclare all the methods from the included API, but documentation
+/// and options are inherited as follows:
+///
+/// - If after comment and whitespace stripping, the documentation
+///   string of the redeclared method is empty, it will be inherited
+///   from the original method.
+///
+/// - Each annotation belonging to the service config (http,
+///   visibility) which is not set in the redeclared method will be
+///   inherited.
+///
+/// - If an http annotation is inherited, the path pattern will be
+///   modified as follows. Any version prefix will be replaced by the
+///   version of the including API plus the [root][] path if specified.
+///
+/// Example of a simple mixin:
+///
+///     package google.acl.v1;
+///     service AccessControl {
+///       // Get the underlying ACL object.
+///       rpc GetAcl(GetAclRequest) returns (Acl) {
+///         option (google.api.http).get = "/v1/{resource=**}:getAcl";
+///       }
+///     }
+///
+///     package google.storage.v2;
+///     service Storage {
+///       rpc GetAcl(GetAclRequest) returns (Acl);
+///
+///       // Get a data record.
+///       rpc GetData(GetDataRequest) returns (Data) {
+///         option (google.api.http).get = "/v2/{resource=**}";
+///       }
+///     }
+///
+/// Example of a mixin configuration:
+///
+///     apis:
+///     - name: google.storage.v2.Storage
+///       mixins:
+///       - name: google.acl.v1.AccessControl
+///
+/// The mixin construct implies that all methods in `AccessControl` are
+/// also declared with same name and request/response types in
+/// `Storage`. A documentation generator or annotation processor will
+/// see the effective `Storage.GetAcl` method after inherting
+/// documentation and annotations as follows:
+///
+///     service Storage {
+///       // Get the underlying ACL object.
+///       rpc GetAcl(GetAclRequest) returns (Acl) {
+///         option (google.api.http).get = "/v2/{resource=**}:getAcl";
+///       }
+///       ...
+///     }
+///
+/// Note how the version in the path pattern changed from `v1` to `v2`.
+///
+/// If the `root` field in the mixin is specified, it should be a
+/// relative path under which inherited HTTP paths are placed. Example:
+///
+///     apis:
+///     - name: google.storage.v2.Storage
+///       mixins:
+///       - name: google.acl.v1.AccessControl
+///         root: acls
+///
+/// This implies the following inherited HTTP annotation:
+///
+///     service Storage {
+///       // Get the underlying ACL object.
+///       rpc GetAcl(GetAclRequest) returns (Acl) {
+///         option (google.api.http).get = "/v2/acls/{resource=**}:getAcl";
+///       }
+///       ...
+///     }
 @interface GPBMixin : GPBMessage
 
-// The fully qualified name of the API which is included.
+/// The fully qualified name of the API which is included.
 @property(nonatomic, readwrite, copy, null_resettable) NSString *name;
 
-// If non-empty specifies a path under which inherited HTTP paths
-// are rooted.
+/// If non-empty specifies a path under which inherited HTTP paths
+/// are rooted.
 @property(nonatomic, readwrite, copy, null_resettable) NSString *root;
 
 @end