exc_server_variants: Templatize and use CompositeMachMessageServer

util/mach/exc_server_variants.h

Index: util/mach/exc_server_variants.h
diff --git a/util/mach/exc_server_variants.h b/util/mach/exc_server_variants.h
index 3552f99f26b67ca2196e0dfe922da6d3c02be2b1..516e1ec41f0217359f63bae2649b55fce7b6f20c 100644
--- a/util/mach/exc_server_variants.h
+++ b/util/mach/exc_server_variants.h
@@ -19,403 +19,14 @@
 
 #include <set>
 
-#include "build/build_config.h"
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 #include "util/mach/mach_message_server.h"
 
 namespace crashpad {
 
-// Routines to provide a single unified front-end to the interfaces in
-// <mach/exc.defs> and <mach/mach_exc.defs>. The two interfaces are identical,
-// except that the latter allows for 64-bit exception codes, and is requested by
-// setting the MACH_EXCEPTION_CODES behavior bit associated with an exception
-// port.
-
 namespace internal {
-
-//! \brief A server interface for the `exc` Mach subsystem.
-class ExcServer : public MachMessageServer::Interface {
- public:
-  //! \brief An interface that the different request messages that are a part of
-  //!     the `exc` Mach subsystem can be dispatched to.
-  class Interface {
-   public:
-    //! \brief Handles exceptions raised by `exception_raise()`.
-    //!
-    //! This behaves equivalently to a `catch_exception_raise()` function used
-    //! with `exc_server()`.
-    //!
-    //! \param[in] trailer The trailer received with the request message.
-    //! \param[out] destroy_request `true` if the request message is to be
-    //!     destroyed even when this method returns success. See
-    //!     MachMessageServer::Interface.
-    virtual kern_return_t CatchExceptionRaise(
-        exception_handler_t exception_port,
-        thread_t thread,
-        task_t task,
-        exception_type_t exception,
-        const exception_data_type_t* code,
-        mach_msg_type_number_t code_count,
-        const mach_msg_trailer_t* trailer,
-        bool* destroy_request) = 0;
-
-    //! \brief Handles exceptions raised by `exception_raise_state()`.
-    //!
-    //! This behaves equivalently to a `catch_exception_raise_state()` function
-    //! used with `exc_server()`.
-    //!
-    //! There is no \a destroy_request parameter because, unlike
-    //! CatchExceptionRaise() and CatchExceptionRaiseStateIdentity(), the
-    //! request message is not complex (it does not carry the \a thread or \a
-    //! task port rights) and thus there is nothing to destroy.
-    //!
-    //! \param[in] trailer The trailer received with the request message.
-    virtual kern_return_t CatchExceptionRaiseState(
-        exception_handler_t exception_port,
-        exception_type_t exception,
-        const exception_data_type_t* code,
-        mach_msg_type_number_t code_count,
-        thread_state_flavor_t* flavor,
-        const natural_t* old_state,
-        mach_msg_type_number_t old_state_count,
-        thread_state_t new_state,
-        mach_msg_type_number_t* new_state_count,
-        const mach_msg_trailer_t* trailer) = 0;
-
-    //! \brief Handles exceptions raised by `exception_raise_state_identity()`.
-    //!
-    //! This behaves equivalently to a `catch_exception_raise_state_identity()`
-    //! function used with `exc_server()`.
-    //!
-    //! \param[in] trailer The trailer received with the request message.
-    //! \param[out] destroy_request `true` if the request message is to be
-    //!     destroyed even when this method returns success. See
-    //!     MachMessageServer::Interface.
-    virtual kern_return_t CatchExceptionRaiseStateIdentity(
-        exception_handler_t exception_port,
-        thread_t thread,
-        task_t task,
-        exception_type_t exception,
-        const exception_data_type_t* code,
-        mach_msg_type_number_t code_count,
-        thread_state_flavor_t* flavor,
-        const natural_t* old_state,
-        mach_msg_type_number_t old_state_count,
-        thread_state_t new_state,
-        mach_msg_type_number_t* new_state_count,
-        const mach_msg_trailer_t* trailer,
-        bool* destroy_request) = 0;
-
-   protected:
-    ~Interface() {}
-  };
-
-  //! \brief Constructs an object of this class.
-  //!
-  //! \param[in] interface The interface to dispatch requests to. Weak.
-  explicit ExcServer(Interface* interface);
-
-  // MachMessageServer::Interface:
-
-  bool MachMessageServerFunction(const mach_msg_header_t* in_header,
-                                 mach_msg_header_t* out_header,
-                                 bool* destroy_complex_request) override;
-
-  std::set<mach_msg_id_t> MachMessageServerRequestIDs() override;
-
-  mach_msg_size_t MachMessageServerRequestSize() override;
-  mach_msg_size_t MachMessageServerReplySize() override;
-
- private:
-  Interface* interface_;  // weak
-
-  DISALLOW_COPY_AND_ASSIGN(ExcServer);
-};
-
-//! \brief A server interface for the `mach_exc` Mach subsystem.
-class MachExcServer : public MachMessageServer::Interface {
- public:
-  //! \brief An interface that the different request messages that are a part of
-  //!     the `mach_exc` Mach subsystem can be dispatched to.
-  class Interface {
-   public:
-    //! \brief Handles exceptions raised by `mach_exception_raise()`.
-    //!
-    //! This behaves equivalently to a `catch_mach_exception_raise()` function
-    //! used with `mach_exc_server()`.
-    //!
-    //! \param[in] trailer The trailer received with the request message.
-    //! \param[out] destroy_request `true` if the request message is to be
-    //!     destroyed even when this method returns success. See
-    //!     MachMessageServer::Interface.
-    virtual kern_return_t CatchMachExceptionRaise(
-        exception_handler_t exception_port,
-        thread_t thread,
-        task_t task,
-        exception_type_t exception,
-        const mach_exception_data_type_t* code,
-        mach_msg_type_number_t code_count,
-        const mach_msg_trailer_t* trailer,
-        bool* destroy_request) = 0;
-
-    //! \brief Handles exceptions raised by `mach_exception_raise_state()`.
-    //!
-    //! This behaves equivalently to a `catch_mach_exception_raise_state()`
-    //! function used with `mach_exc_server()`.
-    //!
-    //! There is no \a destroy_request parameter because, unlike
-    //! CatchMachExceptionRaise() and CatchMachExceptionRaiseStateIdentity(),
-    //! the request message is not complex (it does not carry the \a thread or
-    //! \a task port rights) and thus there is nothing to destroy.
-    //!
-    //! \param[in] trailer The trailer received with the request message.
-    virtual kern_return_t CatchMachExceptionRaiseState(
-        exception_handler_t exception_port,
-        exception_type_t exception,
-        const mach_exception_data_type_t* code,
-        mach_msg_type_number_t code_count,
-        thread_state_flavor_t* flavor,
-        const natural_t* old_state,
-        mach_msg_type_number_t old_state_count,
-        thread_state_t new_state,
-        mach_msg_type_number_t* new_state_count,
-        const mach_msg_trailer_t* trailer) = 0;
-
-    //! \brief Handles exceptions raised by
-    //!     `mach_exception_raise_state_identity()`.
-    //!
-    //! This behaves equivalently to a
-    //! `catch_mach_exception_raise_state_identity()` function used with
-    //! `mach_exc_server()`.
-    //!
-    //! \param[in] trailer The trailer received with the request message.
-    //! \param[out] destroy_request `true` if the request message is to be
-    //!     destroyed even when this method returns success. See
-    //!     MachMessageServer::Interface.
-    virtual kern_return_t CatchMachExceptionRaiseStateIdentity(
-        exception_handler_t exception_port,
-        thread_t thread,
-        task_t task,
-        exception_type_t exception,
-        const mach_exception_data_type_t* code,
-        mach_msg_type_number_t code_count,
-        thread_state_flavor_t* flavor,
-        const natural_t* old_state,
-        mach_msg_type_number_t old_state_count,
-        thread_state_t new_state,
-        mach_msg_type_number_t* new_state_count,
-        const mach_msg_trailer_t* trailer,
-        bool* destroy_request) = 0;
-
-   protected:
-    ~Interface() {}
-  };
-
-  //! \brief Constructs an object of this class.
-  //!
-  //! \param[in] interface The interface to dispatch requests to. Weak.
-  explicit MachExcServer(Interface* interface);
-
-  // MachMessageServer::Interface:
-
-  bool MachMessageServerFunction(const mach_msg_header_t* in_header,
-                                 mach_msg_header_t* out_header,
-                                 bool* destroy_complex_request) override;
-
-  std::set<mach_msg_id_t> MachMessageServerRequestIDs() override;
-
-  mach_msg_size_t MachMessageServerRequestSize() override;
-  mach_msg_size_t MachMessageServerReplySize() override;
-
- private:
-  Interface* interface_;  // weak
-
-  DISALLOW_COPY_AND_ASSIGN(MachExcServer);
-};
-
-//! \brief A server interface for the `exc` Mach subsystem, simplified to have
-//!     only a single interface method needing implementation.
-class SimplifiedExcServer : public ExcServer, public ExcServer::Interface {
- public:
-  //! \brief An interface that the different request messages that are a part of
-  //!     the `exc` Mach subsystem can be dispatched to.
-  class Interface {
-   public:
-    //! \brief Handles exceptions raised by `exception_raise()`,
-    //!     `exception_raise_state()`, and `exception_raise_state_identity()`.
-    //!
-    //! For convenience in implementation, these different “behaviors” of
-    //! exception messages are all mapped to a single interface method. The
-    //! exception’s original “behavior” is specified in the \a behavior
-    //! parameter. Only parameters that were supplied in the request message
-    //! are populated, other parameters are set to reasonable default values.
-    //!
-    //! The meanings of most parameters are identical to that of
-    //! ExcServer::Interface::CatchExceptionRaiseStateIdentity().
-    //!
-    //! \param[in] behavior `EXCEPTION_DEFAULT`, `EXCEPTION_STATE`, or
-    //!     `EXCEPTION_STATE_IDENTITY`, identifying which exception request
-    //!     message was processed and thus which other parameters are valid.
-    virtual kern_return_t CatchException(
-        exception_behavior_t behavior,
-        exception_handler_t exception_port,
-        thread_t thread,
-        task_t task,
-        exception_type_t exception,
-        const exception_data_type_t* code,
-        mach_msg_type_number_t code_count,
-        thread_state_flavor_t* flavor,
-        const natural_t* old_state,
-        mach_msg_type_number_t old_state_count,
-        thread_state_t new_state,
-        mach_msg_type_number_t* new_state_count,
-        const mach_msg_trailer_t* trailer,
-        bool* destroy_complex_request) = 0;
-
-   protected:
-    ~Interface() {}
-  };
-
-  //! \brief Constructs an object of this class.
-  //!
-  //! \param[in] interface The interface to dispatch requests to. Weak.
-  explicit SimplifiedExcServer(Interface* interface);
-
-  // ExcServer::Interface:
-
-  kern_return_t CatchExceptionRaise(exception_handler_t exception_port,
-                                    thread_t thread,
-                                    task_t task,
-                                    exception_type_t exception,
-                                    const exception_data_type_t* code,
-                                    mach_msg_type_number_t code_count,
-                                    const mach_msg_trailer_t* trailer,
-                                    bool* destroy_request) override;
-  kern_return_t CatchExceptionRaiseState(
-      exception_handler_t exception_port,
-      exception_type_t exception,
-      const exception_data_type_t* code,
-      mach_msg_type_number_t code_count,
-      thread_state_flavor_t* flavor,
-      const natural_t* old_state,
-      mach_msg_type_number_t old_state_count,
-      thread_state_t new_state,
-      mach_msg_type_number_t* new_state_count,
-      const mach_msg_trailer_t* trailer) override;
-  kern_return_t CatchExceptionRaiseStateIdentity(
-      exception_handler_t exception_port,
-      thread_t thread,
-      task_t task,
-      exception_type_t exception,
-      const exception_data_type_t* code,
-      mach_msg_type_number_t code_count,
-      thread_state_flavor_t* flavor,
-      const natural_t* old_state,
-      mach_msg_type_number_t old_state_count,
-      thread_state_t new_state,
-      mach_msg_type_number_t* new_state_count,
-      const mach_msg_trailer_t* trailer,
-      bool* destroy_request) override;
-
- private:
-  Interface* interface_;  // weak
-
-  DISALLOW_COPY_AND_ASSIGN(SimplifiedExcServer);
-};
-
-//! \brief A server interface for the `mach_exc` Mach subsystem, simplified to
-//!     have only a single interface method needing implementation.
-class SimplifiedMachExcServer : public MachExcServer,
-                                public MachExcServer::Interface {
- public:
-  //! \brief An interface that the different request messages that are a part of
-  //!     the `mach_exc` Mach subsystem can be dispatched to.
-  class Interface {
-   public:
-    //! \brief Handles exceptions raised by `mach_exception_raise()`,
-    //!     `mach_exception_raise_state()`, and
-    //!     `mach_exception_raise_state_identity()`.
-    //!
-    //! For convenience in implementation, these different “behaviors” of
-    //! exception messages are all mapped to a single interface method. The
-    //! exception’s original “behavior” is specified in the \a behavior
-    //! parameter. Only parameters that were supplied in the request message
-    //! are populated, other parameters are set to reasonable default values.
-    //!
-    //! The meanings of most parameters are identical to that of
-    //! MachExcServer::Interface::CatchMachExceptionRaiseStateIdentity().
-    //!
-    //! \param[in] behavior `MACH_EXCEPTION_CODES | EXCEPTION_DEFAULT`,
-    //!     `MACH_EXCEPTION_CODES | EXCEPTION_STATE`, or
-    //!     `MACH_EXCEPTION_CODES | EXCEPTION_STATE_IDENTITY`, identifying which
-    //!     exception request message was processed and thus which other
-    //!     parameters are valid.
-    virtual kern_return_t CatchMachException(
-        exception_behavior_t behavior,
-        exception_handler_t exception_port,
-        thread_t thread,
-        task_t task,
-        exception_type_t exception,
-        const mach_exception_data_type_t* code,
-        mach_msg_type_number_t code_count,
-        thread_state_flavor_t* flavor,
-        const natural_t* old_state,
-        mach_msg_type_number_t old_state_count,
-        thread_state_t new_state,
-        mach_msg_type_number_t* new_state_count,
-        const mach_msg_trailer_t* trailer,
-        bool* destroy_complex_request) = 0;
-
-   protected:
-    ~Interface() {}
-  };
-
-  //! \brief Constructs an object of this class.
-  //!
-  //! \param[in] interface The interface to dispatch requests to. Weak.
-  explicit SimplifiedMachExcServer(Interface* interface);
-
-  // MachExcServer::Interface:
-
-  kern_return_t CatchMachExceptionRaise(exception_handler_t exception_port,
-                                        thread_t thread,
-                                        task_t task,
-                                        exception_type_t exception,
-                                        const mach_exception_data_type_t* code,
-                                        mach_msg_type_number_t code_count,
-                                        const mach_msg_trailer_t* trailer,
-                                        bool* destroy_request) override;
-  kern_return_t CatchMachExceptionRaiseState(
-      exception_handler_t exception_port,
-      exception_type_t exception,
-      const mach_exception_data_type_t* code,
-      mach_msg_type_number_t code_count,
-      thread_state_flavor_t* flavor,
-      const natural_t* old_state,
-      mach_msg_type_number_t old_state_count,
-      thread_state_t new_state,
-      mach_msg_type_number_t* new_state_count,
-      const mach_msg_trailer_t* trailer) override;
-  kern_return_t CatchMachExceptionRaiseStateIdentity(
-      exception_handler_t exception_port,
-      thread_t thread,
-      task_t task,
-      exception_type_t exception,
-      const mach_exception_data_type_t* code,
-      mach_msg_type_number_t code_count,
-      thread_state_flavor_t* flavor,
-      const natural_t* old_state,
-      mach_msg_type_number_t old_state_count,
-      thread_state_t new_state,
-      mach_msg_type_number_t* new_state_count,
-      const mach_msg_trailer_t* trailer,
-      bool* destroy_request) override;
-
- private:
-  Interface* interface_;  // weak
-
-  DISALLOW_COPY_AND_ASSIGN(SimplifiedMachExcServer);
-};
-
+class UniversalMachExcServerImpl;
 }  // namespace internal
 
 //! \brief A server interface for the `exc` and `mach_exc` Mach subsystems,
@@ -423,18 +34,16 @@ class SimplifiedMachExcServer : public MachExcServer,
 //!     simplified to have only a single interface method needing
 //!     implementation.
 //!
+//! The `<mach/exc.defs>` and `<mach/mach_exc.defs>` interfaces are identical,
+//! except that the latter allows for 64-bit exception codes, and is requested
+//! by setting the MACH_EXCEPTION_CODES behavior bit associated with an
+//! exception port.
+//!
 //! UniversalMachExcServer operates by translating messages received in the
 //! `exc` subsystem to a variant that is compatible with the `mach_exc`
 //! subsystem. This involves changing the format of \a code, the exception code
 //! field, from `exception_data_type_t` to `mach_exception_data_type_t`.
-//! This is achieved by implementing SimplifiedExcServer::Interface and having
-//! it forward translated messages to SimplifiedMachExcServer::Interface, which
-//! is left unimplemented here so that users of this class can provide their own
-//! implementations.
-class UniversalMachExcServer
-    : public MachMessageServer::Interface,
-      public internal::SimplifiedExcServer::Interface,
-      public internal::SimplifiedMachExcServer::Interface {
+class UniversalMachExcServer final : public MachMessageServer::Interface {
  public:
   //! \brief An interface that the different request messages that are a part of
   //!     the `exc` and `mach_exc` Mach subsystems can be dispatched to.
@@ -451,13 +60,20 @@ class UniversalMachExcServer
     //! parameter. Only parameters that were supplied in the request message
     //! are populated, other parameters are set to reasonable default values.
     //!
-    //! The meanings of most parameters are identical to that of
-    //! MachExcServer::Interface::CatchMachExceptionRaiseStateIdentity().
+    //! This behaves equivalently to a `catch_exception_raise_state_identity()`
+    //! function used with `exc_server()`, or a
+    //! `catch_mach_exception_raise_state_identity()` function used with
+    //! `mach_exc_server()`. The meanings of most parameters are identical to
+    //! their meanings to these functions.
     //!
     //! \param[in] behavior `EXCEPTION_DEFAULT`, `EXCEPTION_STATE`,
     //!     or `EXCEPTION_STATE_IDENTITY`, possibly with `MACH_EXCEPTION_CODES`
     //!     ORed in. This identifies which exception request message was
     //!     processed and thus which other parameters are valid.
+    //! \param[in] trailer The trailer received with the request message.
+    //! \param[out] destroy_request `true` if the request message is to be
+    //!     destroyed even when this method returns success. See
+    //!     MachMessageServer::Interface.
     virtual kern_return_t CatchMachException(
         exception_behavior_t behavior,
         exception_handler_t exception_port,
@@ -483,6 +99,8 @@ class UniversalMachExcServer
   //! \param[in] interface The interface to dispatch requests to. Weak.
   explicit UniversalMachExcServer(Interface* interface);
 
+  ~UniversalMachExcServer();
+
   // MachMessageServer::Interface:
 
   bool MachMessageServerFunction(const mach_msg_header_t* in_header,
@@ -494,44 +112,11 @@ class UniversalMachExcServer
   mach_msg_size_t MachMessageServerRequestSize() override;
   mach_msg_size_t MachMessageServerReplySize() override;
 
-  // internal::SimplifiedExcServer::Interface:
-
-  kern_return_t CatchException(exception_behavior_t behavior,
-                               exception_handler_t exception_port,
-                               thread_t thread,
-                               task_t task,
-                               exception_type_t exception,
-                               const exception_data_type_t* code,
-                               mach_msg_type_number_t code_count,
-                               thread_state_flavor_t* flavor,
-                               const natural_t* old_state,
-                               mach_msg_type_number_t old_state_count,
-                               thread_state_t new_state,
-                               mach_msg_type_number_t* new_state_count,
-                               const mach_msg_trailer_t* trailer,
-                               bool* destroy_complex_request) override;
-
-  // internal::SimplifiedMachExcServer::Interface:
-
-  kern_return_t CatchMachException(exception_behavior_t behavior,
-                                   exception_handler_t exception_port,
-                                   thread_t thread,
-                                   task_t task,
-                                   exception_type_t exception,
-                                   const mach_exception_data_type_t* code,
-                                   mach_msg_type_number_t code_count,
-                                   thread_state_flavor_t* flavor,
-                                   const natural_t* old_state,
-                                   mach_msg_type_number_t old_state_count,
-                                   thread_state_t new_state,
-                                   mach_msg_type_number_t* new_state_count,
-                                   const mach_msg_trailer_t* trailer,
-                                   bool* destroy_complex_request) override;
-
  private:
-  internal::SimplifiedExcServer exc_server_;
-  internal::SimplifiedMachExcServer mach_exc_server_;
-  Interface* interface_;  // weak
+  // Pointer-to-implementation (pimpl). The implementation relies on internal

[Robert Sesek, 2014/12/11 16:32:28]

Not sure this comment is even necessary.

+  // templatized classes, and it’s cleaner to not expose them in this header
+  // file.
+  scoped_ptr<internal::UniversalMachExcServerImpl> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(UniversalMachExcServer);
 };