win: support x64 reading x86 (wow64)

snapshot/win/crashpad_snapshot_test_crashing_child.cc

 // Copyright 2015 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 <stdint.h>
 #include <stdlib.h>
+#include <windows.h>
+
+#include "base/logging.h"
+#include "client/crashpad_client.h"
+#include "util/file/file_io.h"
+
+__declspec(noinline) uint64_t CurrentAddress() {
+  return reinterpret_cast<uint64_t>(_ReturnAddress());
+}
 
 int main(int argc, char* argv[]) {
-  return EXIT_SUCCESS;
+  CHECK_EQ(argc, 2);
+
+  crashpad::CrashpadClient client;
+  CHECK(client.SetHandler(argv[1]));
+  CHECK(client.UseHandler());
+
+  HANDLE out = GetStdHandle(STD_OUTPUT_HANDLE);
+  CHECK_NE(out, INVALID_HANDLE_VALUE);
+  uint64_t break_address = CurrentAddress();
+  crashpad::CheckedWriteFile(out, &break_address, sizeof(break_address));
+
+  __debugbreak();
+
+  return 0;
 }