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 "client/crashpad_client.h"
+#include <stdint.h>
+#include <stdlib.h>
+#include <windows.h>
 
 #include "base/logging.h"
-#include "tools/tool_support.h"
+#include "client/crashpad_client.h"
+#include "util/file/file_io.h"
+#include "util/win/address_types.h"
 
-namespace crashpad {
-namespace {
-
-void SomeCrashyFunction() {
-  volatile int* foo = reinterpret_cast<volatile int*>(7);
-  *foo = 42;
+__declspec(noinline) crashpad::WinVMAddress CurrentAddress() {
+  return reinterpret_cast<crashpad::WinVMAddress>(_ReturnAddress());
 }
 
-int CrashyMain(int argc, char* argv[]) {
-  if (argc != 2) {
-    fprintf(stderr, "Usage: %s <server_pipe_name>\n", argv[0]);
-    return 1;
-  }
+int main(int argc, char* argv[]) {
+  CHECK_EQ(argc, 2);
 
-  CrashpadClient client;
-  if (!client.SetHandler(argv[1])) {
-    LOG(ERROR) << "SetHandler";
-    return 1;
-  }
-  if (!client.UseHandler()) {
-    LOG(ERROR) << "UseHandler";
-    return 1;
-  }
+  crashpad::CrashpadClient client;
+  CHECK(client.SetHandler(argv[1]));
+  CHECK(client.UseHandler());
 
-  SomeCrashyFunction();
+  HANDLE out = GetStdHandle(STD_OUTPUT_HANDLE);
+  CHECK_NE(out, INVALID_HANDLE_VALUE);
+  crashpad::WinVMAddress break_address = CurrentAddress();
+  crashpad::CheckedWriteFile(out, &break_address, sizeof(break_address));
+
+  __debugbreak();
 
   return 0;
 }
-
-}  // namespace
-}  // namespace crashpad
-
-int wmain(int argc, wchar_t* argv[]) {
-  return crashpad::ToolSupport::Wmain(argc, argv, crashpad::CrashyMain);
-}