HResult.cxx

/*
 * Copyright 2020-2021 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifdef _WIN32
// COM needs the "MSG" typedef, and audiopolicy.h includes COM headers
#undef NOUSER
#endif

#include "HResult.hxx"
#include "system/Error.hxx"

#include <cassert>
#include <cstdarg>
#include <cstdio>
#include <memory>

#include <combaseapi.h> // needed by audiopolicy.h if COM_NO_WINDOWS_H is defined
#include <audiopolicy.h>

std::string_view
HRESULTToString(HRESULT result) noexcept
{
	using namespace std::literals;
	switch (result) {
#define C(x)                                                                             \
case x:                                                                                  \
	return #x##sv
		C(AUDCLNT_E_ALREADY_INITIALIZED);
		C(AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL);
		C(AUDCLNT_E_BUFFER_ERROR);
		C(AUDCLNT_E_BUFFER_OPERATION_PENDING);
		C(AUDCLNT_E_BUFFER_SIZE_ERROR);
		C(AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED);
		C(AUDCLNT_E_BUFFER_TOO_LARGE);
		C(AUDCLNT_E_CPUUSAGE_EXCEEDED);
		C(AUDCLNT_E_DEVICE_INVALIDATED);
		C(AUDCLNT_E_DEVICE_IN_USE);
		C(AUDCLNT_E_ENDPOINT_CREATE_FAILED);
		C(AUDCLNT_E_EXCLUSIVE_MODE_NOT_ALLOWED);
		C(AUDCLNT_E_INVALID_DEVICE_PERIOD);
		C(AUDCLNT_E_OUT_OF_ORDER);
		C(AUDCLNT_E_SERVICE_NOT_RUNNING);
		C(AUDCLNT_E_UNSUPPORTED_FORMAT);
		C(AUDCLNT_E_WRONG_ENDPOINT_TYPE);
		C(AUDCLNT_E_NOT_INITIALIZED);
		C(AUDCLNT_E_NOT_STOPPED);
		C(CO_E_NOTINITIALIZED);
		C(E_INVALIDARG);
		C(E_OUTOFMEMORY);
		C(E_POINTER);
		C(NO_ERROR);
#undef C
	}
	return std::string_view();
}

std::string
HResultCategory::message(int Errcode) const
{
	char buffer[256];

	/* FormatMessage() supports some HRESULT values (depending on
	   the Windows version) */
	if (FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
			   FORMAT_MESSAGE_IGNORE_INSERTS,
			   nullptr, Errcode, 0,
			   buffer, sizeof(buffer),
			   nullptr))
		return buffer;

	const auto msg = HRESULTToString(Errcode);
	if (!msg.empty())
		return std::string(msg);

	int size = snprintf(buffer, sizeof(buffer), "0x%1x", Errcode);
	assert(2 <= size && size <= 10);
	return std::string(buffer, size);
}

std::system_error
FormatHResultError(HRESULT result, const char *fmt, ...) noexcept
{
	std::va_list args1, args2;
	va_start(args1, fmt);
	va_copy(args2, args1);

	const int size = vsnprintf(nullptr, 0, fmt, args1);
	va_end(args1);
	assert(size >= 0);

	auto buffer = std::make_unique<char[]>(size + 1);
	vsprintf(buffer.get(), fmt, args2);
	va_end(args2);

	return std::system_error(std::error_code(result, hresult_category()),
				 std::string(buffer.get(), size));
}