Add ScopeExit

third_party/host_memory/host_memory.cpp

@@ -30,7 +30,7 @@
 
 #include <boost/icl/interval_set.hpp>
 
-#include "common/scope_exit.h"
+#include <host_memory/scope_exit.h>
 
 
 #ifndef MAP_NORESERVE

third_party/host_memory/include/host_memory/scope_exit.h

@@ -0,0 +1,78 @@
+// SPDX-FileCopyrightText: 2014 Citra Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <utility>
+
+namespace detail {
+	template <class F>
+	class ScopeGuard {
+		ScopeGuard(const ScopeGuard&) = delete;
+		ScopeGuard& operator=(const ScopeGuard&) = delete;
+
+	  private:
+		F f;
+		bool active;
+
+	  public:
+		constexpr ScopeGuard(F f_) : f(std::move(f_)), active(true) {}
+		constexpr ~ScopeGuard() {
+			if (active) {
+				f();
+			}
+		}
+
+		constexpr void Cancel() { active = false; }
+		constexpr ScopeGuard(ScopeGuard&& rhs) : f(std::move(rhs.f)), active(rhs.active) { rhs.Cancel(); }
+
+		ScopeGuard& operator=(ScopeGuard&& rhs) = delete;
+	};
+
+	template <class F>
+	constexpr ScopeGuard<F> MakeScopeGuard(F f) {
+		return ScopeGuard<F>(std::move(f));
+	}
+
+	enum class ScopeGuardOnExit {};
+
+	template <typename F>
+	constexpr ScopeGuard<F> operator+(ScopeGuardOnExit, F&& f) {
+		return ScopeGuard<F>(std::forward<F>(f));
+	}
+
+}  // namespace detail
+
+#define CONCATENATE_IMPL(s1, s2) s1##s2
+#define CONCATENATE(s1, s2) CONCATENATE_IMPL(s1, s2)
+
+#ifdef __COUNTER__
+#define ANONYMOUS_VARIABLE(pref) CONCATENATE(pref, __COUNTER__)
+#else
+#define ANONYMOUS_VARIABLE(pref) CONCATENATE(pref, __LINE__)
+#endif
+
+/**
+ * This macro is similar to SCOPE_EXIT, except the object is caller managed. This is intended to be
+ * used when the caller might want to cancel the ScopeExit.
+ */
+#define SCOPE_GUARD detail::ScopeGuardOnExit() + [&]()
+
+/**
+ * This macro allows you to conveniently specify a block of code that will run on scope exit. Handy
+ * for doing ad-hoc clean-up tasks in a function with multiple returns.
+ *
+ * Example usage:
+ * \code
+ * const int saved_val = g_foo;
+ * g_foo = 55;
+ * SCOPE_EXIT{ g_foo = saved_val; };
+ *
+ * if (Bar()) {
+ *     return 0;
+ * } else {
+ *     return 20;
+ * }
+ * \endcode
+ */
+#define SCOPE_EXIT auto ANONYMOUS_VARIABLE(SCOPE_EXIT_STATE_) = SCOPE_GUARD