Refactor minidump test utilities for MinidumpWritable, …

minidump/minidump_system_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,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #include "minidump/minidump_system_info_writer.h"
 
 #include <dbghelp.h>
 #include <string.h>
 
 #include <string>
 
 #include "gtest/gtest.h"
 #include "minidump/minidump_file_writer.h"
 #include "minidump/test/minidump_file_writer_test_util.h"
+#include "minidump/test/minidump_string_writer_test_util.h"
 #include "util/file/string_file_writer.h"
 
 namespace crashpad {
 namespace test {
 namespace {
 
 void GetSystemInfoStream(const std::string& file_contents,
                          size_t csd_version_length,
                          const MINIDUMP_SYSTEM_INFO** system_info,
                          const MINIDUMP_STRING** csd_version) {
   // The expected number of bytes for the CSD version’s MINIDUMP_STRING::Buffer.
   const size_t kCSDVersionBytes =
       csd_version_length * sizeof(MINIDUMP_STRING::Buffer[0]);
   const size_t kCSDVersionBytesWithNUL =
       kCSDVersionBytes + sizeof(MINIDUMP_STRING::Buffer[0]);
 
   const size_t kDirectoryOffset = sizeof(MINIDUMP_HEADER);
   const size_t kSystemInfoStreamOffset =
       kDirectoryOffset + sizeof(MINIDUMP_DIRECTORY);
   const size_t kCSDVersionOffset =
       kSystemInfoStreamOffset + sizeof(MINIDUMP_SYSTEM_INFO);
   const size_t kFileSize =
       kCSDVersionOffset + sizeof(MINIDUMP_STRING) + kCSDVersionBytesWithNUL;
 
   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(kMinidumpStreamTypeSystemInfo, directory->StreamType);
-  ASSERT_EQ(sizeof(MINIDUMP_SYSTEM_INFO), directory->Location.DataSize);
-  ASSERT_EQ(kSystemInfoStreamOffset, directory->Location.Rva);
+  ASSERT_EQ(kMinidumpStreamTypeSystemInfo, directory[0].StreamType);
+  ASSERT_EQ(sizeof(MINIDUMP_SYSTEM_INFO), directory[0].Location.DataSize);
+  ASSERT_EQ(kSystemInfoStreamOffset, directory[0].Location.Rva);
 
   *system_info = reinterpret_cast<const MINIDUMP_SYSTEM_INFO*>(
       &file_contents[kSystemInfoStreamOffset]);
 
   ASSERT_EQ(kCSDVersionOffset, (*system_info)->CSDVersionRva);
 
-  *csd_version = reinterpret_cast<const MINIDUMP_STRING*>(
-      &file_contents[kCSDVersionOffset]);
-
+  *csd_version =
+      MinidumpStringAtRVA(file_contents, (*system_info)->CSDVersionRva);
   ASSERT_EQ(kCSDVersionBytes, (*csd_version)->Length);
 }
 
 TEST(MinidumpSystemInfoWriter, Empty) {
   MinidumpFileWriter minidump_file_writer;
   MinidumpSystemInfoWriter system_info_writer;
 
   system_info_writer.SetCSDVersion(std::string());
 
   minidump_file_writer.AddStream(&system_info_writer);
@@ skipping 194 matching lines @@
   minidump_file_writer.AddStream(&system_info_writer);
 
   StringFileWriter file_writer;
   ASSERT_DEATH(minidump_file_writer.WriteEverything(&file_writer),
                "csd_version_");
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace crashpad