/*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#pragma once
+#include <cstdlib>
+
#include <folly/Portability.h>
-#include <glog/logging.h>
namespace folly {
+namespace detail {
+
+extern void assume_check(bool cond);
+
+}
+
/**
* Inform the compiler that the argument can be assumed true. It is
* undefined behavior if the argument is not actually true, so use
*/
FOLLY_ALWAYS_INLINE void assume(bool cond) {
-#ifndef NDEBUG
- DCHECK(cond);
-#elif defined(__clang__) // Must go first because Clang also defines __GNUC__.
- __builtin_assume(cond);
+ if (kIsDebug) {
+ detail::assume_check(cond);
+ } else {
+#if defined(__clang__) // Must go first because Clang also defines __GNUC__.
+ __builtin_assume(cond);
#elif defined(__GNUC__)
- if (!cond) { __builtin_unreachable(); }
+ if (!cond) { __builtin_unreachable(); }
+#elif defined(_MSC_VER)
+ __assume(cond);
+#else
+ // Do nothing.
+#endif
+ }
+}
+
+[[noreturn]] FOLLY_ALWAYS_INLINE void assume_unreachable() {
+ assume(false);
+ // Do a bit more to get the compiler to understand
+ // that this function really will never return.
+#if defined(__GNUC__)
+ __builtin_unreachable();
#elif defined(_MSC_VER)
- __assume(cond);
+ __assume(0);
#else
- // Do nothing.
+ // Well, it's better than nothing.
+ std::abort();
#endif
}