Refactor minidump test utilities for MinidumpWritable, …

minidump/minidump_misc_info_writer_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 24 matching lines @@
 template <typename T>
 void GetMiscInfoStream(const std::string& file_contents, const T** misc_info) {
   const size_t kDirectoryOffset = sizeof(MINIDUMP_HEADER);
   const size_t kMiscInfoStreamOffset =
       kDirectoryOffset + sizeof(MINIDUMP_DIRECTORY);
   const size_t kMiscInfoStreamSize = sizeof(T);
   const size_t kFileSize = kMiscInfoStreamOffset + kMiscInfoStreamSize;
 
   ASSERT_EQ(kFileSize, file_contents.size());
 
+  const MINIDUMP_DIRECTORY* directory;
   const MINIDUMP_HEADER* header =
-      reinterpret_cast<const MINIDUMP_HEADER*>(&file_contents[0]);
+      MinidumpHeaderAtStart(file_contents, &directory);
+  ASSERT_NO_FATAL_FAILURE(VerifyMinidumpHeader(header, 1, 0));
+  ASSERT_TRUE(directory);
 
-  ASSERT_NO_FATAL_FAILURE(VerifyMinidumpHeader(header, 1, 0));
-
-  const MINIDUMP_DIRECTORY* directory =
-      reinterpret_cast<const MINIDUMP_DIRECTORY*>(
-          &file_contents[kDirectoryOffset]);
-
-  ASSERT_EQ(kMinidumpStreamTypeMiscInfo, directory->StreamType);
-  ASSERT_EQ(kMiscInfoStreamSize, directory->Location.DataSize);
-  ASSERT_EQ(kMiscInfoStreamOffset, directory->Location.Rva);
+  ASSERT_EQ(kMinidumpStreamTypeMiscInfo, directory[0].StreamType);
+  ASSERT_EQ(kMiscInfoStreamSize, directory[0].Location.DataSize);
+  ASSERT_EQ(kMiscInfoStreamOffset, directory[0].Location.Rva);
 
   *misc_info =
       reinterpret_cast<const T*>(&file_contents[kMiscInfoStreamOffset]);
 
   ASSERT_EQ(kMiscInfoStreamSize, (*misc_info)->SizeOfInfo);
 }
 
 void ExpectNULPaddedString16Equal(const char16* expected,
                                   const char16* observed,
                                   size_t size) {
@@ skipping 544 matching lines @@
   c16lcpy(expected.DbgBldStr,
           debug_build_string_utf16.c_str(),
           arraysize(expected.DbgBldStr));
 
   ExpectMiscInfoEqual(&expected, observed);
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace crashpad