contrib/plugins: add empty cpp plugin

This plugin makes sure we can compile in C++ while including qemu-plugin
header. It includes all C++ standard headers, up to C++23 standard,
minus the ones that are missing in the oldest environments we need to
build for.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Link: https://lore.kernel.org/qemu-devel/20260124182921.531562-12-pierrick.bouvier@linaro.org
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>

1 files changed, 119 insertions, 0 deletions

diff --git a/contrib/plugins/cpp.cpp b/contrib/plugins/cpp.cpp
new file mode 100644
index 0000000000..1ff54896d9
--- /dev/null
+++ b/contrib/plugins/cpp.cpp
@@ -0,0 +1,119 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This C++ plugin ensures we don't have regression when compiling C++.
+ */
+
+#include <qemu-plugin.h>
+
+/* https://en.cppreference.com/w/cpp/headers.html */
+#include <algorithm>
+#include <any>
+#include <array>
+#include <atomic>
+#include <barrier>
+#include <bit>
+#include <bitset>
+#include <cassert>
+#include <cctype>
+#include <cerrno>
+#include <cfenv>
+#include <cfloat>
+#include <charconv>
+#include <chrono>
+#include <cinttypes>
+#include <climits>
+#include <clocale>
+#include <cmath>
+#include <codecvt>
+#include <compare>
+#include <complex>
+#include <concepts>
+#include <condition_variable>
+#include <coroutine>
+#include <csetjmp>
+#include <csignal>
+#include <cstdarg>
+#include <cstddef>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <ctime>
+#include <cuchar>
+#include <cwchar>
+#include <cwctype>
+#include <deque>
+#include <exception>
+#include <execution>
+#include <filesystem>
+#include <forward_list>
+#include <fstream>
+#include <functional>
+#include <future>
+#include <initializer_list>
+#include <iomanip>
+#include <ios>
+#include <iosfwd>
+#include <iostream>
+#include <istream>
+#include <iterator>
+#include <latch>
+#include <limits>
+#include <list>
+#include <locale>
+#include <map>
+#include <memory>
+#include <memory_resource>
+#include <mutex>
+#include <new>
+#include <numbers>
+#include <numeric>
+#include <optional>
+#include <ostream>
+#include <queue>
+#include <random>
+#include <ranges>
+#include <ratio>
+#include <regex>
+#include <scoped_allocator>
+#include <semaphore>
+#include <set>
+#include <shared_mutex>
+#include <source_location>
+#include <span>
+#include <sstream>
+#include <stack>
+#include <stdexcept>
+#include <stop_token>
+#include <streambuf>
+#include <string>
+#include <string_view>
+#include <syncstream>
+#include <system_error>
+#include <thread>
+#include <tuple>
+#include <typeindex>
+#include <typeinfo>
+#include <type_traits>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <valarray>
+#include <variant>
+#include <vector>
+#include <version>
+
+QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
+
+static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
+{
+}
+
+QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
+                                           const qemu_info_t *info,
+                                           int argc, char **argv)
+{
+    qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
+    return 0;
+}