Add ExcServerCopyState()

util/mach/exc_server_variants_test.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 1014 matching lines @@
       EXPECT_EQ(nullptr, old_state);
       EXPECT_EQ(0u, *new_state_count);
       EXPECT_EQ(nullptr, new_state);
     }
 
     EXPECT_EQ(implicit_cast<mach_msg_trailer_type_t>(MACH_MSG_TRAILER_FORMAT_0),
               trailer->msgh_trailer_type);
     EXPECT_EQ(REQUESTED_TRAILER_SIZE(kMachMessageOptions),
               trailer->msgh_trailer_size);
 
+    ExcServerCopyState(
+        behavior, old_state, old_state_count, new_state, new_state_count);
+
     return ExcServerSuccessfulReturnValue(behavior, false);
   }
 
  private:
   // MachMultiprocess:
 
   void MachMultiprocessParent() override {
     UniversalMachExcServer universal_mach_exc_server(this);
 
     kern_return_t kr =
@@ skipping 223 matching lines @@
                            index,
                            test_data.behavior,
                            test_data.set_thread_state ? "true" : "false"));
 
     EXPECT_EQ(test_data.kr,
               ExcServerSuccessfulReturnValue(test_data.behavior,
                                              test_data.set_thread_state));
   }
 }
 
+TEST(ExcServerVariants, ExcServerCopyState) {
+  const natural_t old_state[] = {1, 2, 3, 4, 5};
+  natural_t new_state[10] = {};
+
+  const mach_msg_type_number_t old_state_count = arraysize(old_state);
+  mach_msg_type_number_t new_state_count = arraysize(new_state);
+
+  // EXCEPTION_DEFAULT (with or without MACH_EXCEPTION_CODES) is not
+  // state-carrying. new_state and new_state_count should be untouched.
+  ExcServerCopyState(EXCEPTION_DEFAULT,
+                     old_state,
+                     old_state_count,
+                     new_state,
+                     &new_state_count);
+  EXPECT_EQ(arraysize(new_state), new_state_count);
+  for (size_t i = 0; i < arraysize(new_state); ++i) {
+    EXPECT_EQ(0u, new_state[i]) << "i " << i;
+  }
+
+  ExcServerCopyState(MACH_EXCEPTION_CODES | EXCEPTION_DEFAULT,
+                     old_state,
+                     old_state_count,
+                     new_state,
+                     &new_state_count);
+  EXPECT_EQ(arraysize(new_state), new_state_count);
+  for (size_t i = 0; i < arraysize(new_state); ++i) {
+    EXPECT_EQ(0u, new_state[i]) << "i " << i;
+  }
+
+  // This is a state-carrying exception where old_state_count is small.
+  mach_msg_type_number_t copy_limit = 2;
+  ExcServerCopyState(
+      EXCEPTION_STATE, old_state, copy_limit, new_state, &new_state_count);
+  EXPECT_EQ(copy_limit, new_state_count);
+  for (size_t i = 0; i < copy_limit; ++i) {
+    EXPECT_EQ(old_state[i], new_state[i]) << "i " << i;
+  }
+  for (size_t i = copy_limit; i < arraysize(new_state); ++i) {
+    EXPECT_EQ(0u, new_state[i]) << "i " << i;
+  }
+
+  // This is a state-carrying exception where new_state_count is small.
+  copy_limit = 3;
+  new_state_count = copy_limit;
+  ExcServerCopyState(EXCEPTION_STATE_IDENTITY,
+                     old_state,
+                     old_state_count,
+                     new_state,
+                     &new_state_count);
+  EXPECT_EQ(copy_limit, new_state_count);
+  for (size_t i = 0; i < copy_limit; ++i) {
+    EXPECT_EQ(old_state[i], new_state[i]) << "i " << i;
+  }
+  for (size_t i = copy_limit; i < arraysize(new_state); ++i) {
+    EXPECT_EQ(0u, new_state[i]) << "i " << i;
+  }
+
+  // This is a state-carrying exception where all of old_state is copied to
+  // new_state, which is large enough to receive it and then some.
+  new_state_count = arraysize(new_state);
+  ExcServerCopyState(MACH_EXCEPTION_CODES | EXCEPTION_STATE_IDENTITY,
+                     old_state,
+                     old_state_count,
+                     new_state,
+                     &new_state_count);
+  EXPECT_EQ(old_state_count, new_state_count);
+  for (size_t i = 0; i < arraysize(old_state); ++i) {
+    EXPECT_EQ(old_state[i], new_state[i]) << "i " << i;
+  }
+  for (size_t i = arraysize(old_state); i < arraysize(new_state); ++i) {
+    EXPECT_EQ(0u, new_state[i]) << "i " << i;
+  }
+}
+
 }  // namespace
 }  // namespace test
 }  // namespace crashpad