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// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_CRASH_CONTENT_APP_FALLBACK_CRASH_HANDLER_LAUNCHER_WIN_H_
#define COMPONENTS_CRASH_CONTENT_APP_FALLBACK_CRASH_HANDLER_LAUNCHER_WIN_H_
#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/macros.h"
#include "base/win/scoped_handle.h"
#include "base/win/startup_information.h"
#include <windows.h>
namespace crash_reporter {
// This class is a last-ditch crash handler for the Crashpad handler process.
// It prepares and stores a command line, ready for dispatching when
// an exception occurs. Everything needed to call CreateProcess is pre-allocated
// to minimize the odds of re-faulting due to e.g. tripping over the same issue
// that caused the initial crash.
// This is still very much best-effort, as doing anything at all inside a
// process that's crashed is always going to be iffy^2.
class FallbackCrashHandlerLauncher {
public:
FallbackCrashHandlerLauncher();
~FallbackCrashHandlerLauncher();
// Initializes everything that's needed in LaunchAndWaitForHandler.
bool Initialize(const base::CommandLine& program,
const base::FilePath& crashpad_database);
// Launch the pre-computed command line for the fallback error handler.
// The expectation is that this function will never return, as the fallback
// error handler should terminate it with the exception code as the process
// exit code. The return value from this function is therefore academic in
// the normal case.
// However, for completeness, this function returns one of:
// - The error from CreateProcess if it fails to launch the fallback handler.
// - The error from waiting on the fallback crash handler process if it
// fails to wait for that process to exit.
// - The exit code from the fallback crash handler process.
// - The error encountered in retrieving the crash handler process' exit code.
// Note that the return value is used in testing.
DWORD LaunchAndWaitForHandler(EXCEPTION_POINTERS* pointers);
private:
// A copy of the actual exception pointers made at time of exception.
EXCEPTION_POINTERS exception_pointers_;
// The precomputed startup info and command line for launching the fallback
// handler.
base::win::StartupInformation startup_info_;
// Stores the pre-cooked command line, with an allotment of zeros at the back
// sufficient for writing in the thread id, just before launch.
std::vector<wchar_t> cmd_line_;
// An inheritable handle to our own process, the raw handle is necessary
// for pre-computing the startup info.
base::win::ScopedHandle self_process_handle_;
DISALLOW_COPY_AND_ASSIGN(FallbackCrashHandlerLauncher);
};
} // namespace crash_reporter
#endif // COMPONENTS_CRASH_CONTENT_APP_FALLBACK_CRASH_HANDLER_LAUNCHER_WIN_H_