UniversalMachExcServer: eliminate multiple implementation inheritance

util/mach/exc_server_variants.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 472 matching lines @@
     mach_msg_type_number_t code_count,
     const mach_msg_trailer_t* trailer,
     bool* destroy_request) {
   thread_state_flavor_t flavor = THREAD_STATE_NONE;
   mach_msg_type_number_t new_state_count = 0;
   return interface_->CatchException(EXCEPTION_DEFAULT,
                                     exception_port,
                                     thread,
                                     task,
                                     exception,
-                                    code,
+                                    code_count ? code : nullptr,
                                     code_count,
                                     &flavor,
                                     nullptr,
                                     0,
                                     nullptr,
                                     &new_state_count,
                                     trailer,
                                     destroy_request);
 }
 
 kern_return_t SimplifiedExcServer::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) {
   bool destroy_complex_request = false;
   return interface_->CatchException(EXCEPTION_STATE,
                                     exception_port,
                                     THREAD_NULL,
                                     TASK_NULL,
                                     exception,
-                                    code,
+                                    code_count ? code : nullptr,
                                     code_count,
                                     flavor,
-                                    old_state,
+                                    old_state_count ? old_state : nullptr,
                                     old_state_count,
-                                    new_state,
+                                    new_state_count ? new_state : nullptr,
                                     new_state_count,
                                     trailer,
                                     &destroy_complex_request);
 }
 
 kern_return_t SimplifiedExcServer::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) {
   return interface_->CatchException(EXCEPTION_STATE_IDENTITY,
                                     exception_port,
                                     thread,
                                     task,
                                     exception,
-                                    code,
+                                    code_count ? code : nullptr,
                                     code_count,
                                     flavor,
-                                    old_state,
+                                    old_state_count ? old_state : nullptr,
                                     old_state_count,
-                                    new_state,
+                                    new_state_count ? new_state : nullptr,
                                     new_state_count,
                                     trailer,
                                     destroy_request);
 }
 
 SimplifiedMachExcServer::SimplifiedMachExcServer(
     SimplifiedMachExcServer::Interface* interface)
     : MachExcServer(this),
       MachExcServer::Interface(),
       interface_(interface) {
 }
 
 kern_return_t SimplifiedMachExcServer::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) {
   thread_state_flavor_t flavor = THREAD_STATE_NONE;
   mach_msg_type_number_t new_state_count = 0;
   return interface_->CatchMachException(
       EXCEPTION_DEFAULT | MACH_EXCEPTION_CODES,
       exception_port,
       thread,
       task,
       exception,
-      code,
+      code_count ? code : nullptr,
       code_count,
       &flavor,
       nullptr,
       0,
       nullptr,
       &new_state_count,
       trailer,
       destroy_request);
 }
 
 kern_return_t SimplifiedMachExcServer::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) {
   bool destroy_complex_request = false;
   return interface_->CatchMachException(EXCEPTION_STATE | MACH_EXCEPTION_CODES,
                                         exception_port,
                                         THREAD_NULL,
                                         TASK_NULL,
                                         exception,
-                                        code,
+                                        code_count ? code : nullptr,
                                         code_count,
                                         flavor,
-                                        old_state,
+                                        old_state_count ? old_state : nullptr,
                                         old_state_count,
-                                        new_state,
+                                        new_state_count ? new_state : nullptr,
                                         new_state_count,
                                         trailer,
                                         &destroy_complex_request);
 }
 
 kern_return_t SimplifiedMachExcServer::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) {
   return interface_->CatchMachException(
       EXCEPTION_STATE_IDENTITY | MACH_EXCEPTION_CODES,
       exception_port,
       thread,
       task,
       exception,
-      code,
+      code_count ? code : nullptr,
       code_count,
       flavor,
-      old_state,
+      old_state_count ? old_state : nullptr,
       old_state_count,
-      new_state,
+      new_state_count ? new_state : nullptr,
       new_state_count,
       trailer,
       destroy_request);
 }
 
 }  // namespace internal
 
-UniversalMachExcServer::UniversalMachExcServer()
+UniversalMachExcServer::UniversalMachExcServer(
+    UniversalMachExcServer::Interface* interface)
     : MachMessageServer::Interface(),
       internal::SimplifiedExcServer::Interface(),
       internal::SimplifiedMachExcServer::Interface(),
       exc_server_(this),
-      mach_exc_server_(this) {
+      mach_exc_server_(this),
+      interface_(interface) {
 }
 
 bool UniversalMachExcServer::MachMessageServerFunction(
     const mach_msg_header_t* in_header,
     mach_msg_header_t* out_header,
     bool* destroy_complex_request) {
   switch (in_header->msgh_id) {
     case kMachMessageIDMachExceptionRaise:
     case kMachMessageIDMachExceptionRaiseState:
     case kMachMessageIDMachExceptionRaiseStateIdentity:
@@ skipping 37 matching lines @@
     thread_state_t new_state,
     mach_msg_type_number_t* new_state_count,
     const mach_msg_trailer_t* trailer,
     bool* destroy_complex_request) {
   std::vector<mach_exception_data_type_t> mach_codes;
   mach_codes.reserve(code_count);
   for (size_t index = 0; index < code_count; ++index) {
     mach_codes.push_back(code[index]);
   }
 
-  return CatchMachException(behavior,
-                            exception_port,
-                            thread,
-                            task,
-                            exception,
-                            code_count ? &mach_codes[0] : nullptr,
-                            code_count,
-                            flavor,
-                            old_state,
-                            old_state_count,
-                            new_state,
-                            new_state_count,
-                            trailer,
-                            destroy_complex_request);
+  return interface_->CatchMachException(behavior,
+                                        exception_port,
+                                        thread,
+                                        task,
+                                        exception,
+                                        code_count ? &mach_codes[0] : nullptr,
+                                        code_count,
+                                        flavor,
+                                        old_state_count ? old_state : nullptr,
+                                        old_state_count,
+                                        new_state_count ? new_state : nullptr,
+                                        new_state_count,
+                                        trailer,
+                                        destroy_complex_request);
+}
+
+kern_return_t UniversalMachExcServer::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) {
+  return interface_->CatchMachException(behavior,
+                                        exception_port,
+                                        thread,
+                                        task,
+                                        exception,
+                                        code_count ? code : nullptr,
+                                        code_count,
+                                        flavor,
+                                        old_state_count ? old_state : nullptr,
+                                        old_state_count,
+                                        new_state_count ? new_state : nullptr,
+                                        new_state_count,
+                                        trailer,
+                                        destroy_complex_request);
 }
 
 exception_type_t ExcCrashRecoverOriginalException(
     mach_exception_code_t code_0,
     mach_exception_code_t* original_code_0,
     int* signal) {
   // 10.9.4 xnu-2422.110.17/bsd/kern/kern_exit.c proc_prepareexit() sets code[0]
   // based on the signal value, original exception type, and low 20 bits of the
   // original code[0] before calling xnu-2422.110.17/osfmk/kern/exception.c
   // task_exception_notify() to raise an EXC_CRASH.
@@ skipping 19 matching lines @@
 kern_return_t ExcServerSuccessfulReturnValue(exception_behavior_t behavior,
                                              bool set_thread_state) {
   if (!set_thread_state && ExceptionBehaviorHasState(behavior)) {
     return MACH_RCV_PORT_DIED;
   }
 
   return KERN_SUCCESS;
 }
 
 }  // namespace crashpad