Diagnose invalid memory orderings in <atomic>

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@291976 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__config b/include/__config
index fec9642..8b7897d 100644
--- a/include/__config
+++ b/include/__config
@@ -1008,9 +1008,9 @@
 
 #if __has_attribute(diagnose_if) && !defined(_LIBCPP_DISABLE_ADDITIONAL_DIAGNOSTICS)
 # define _LIBCPP_DIAGNOSE_WARNING(...) \
-    __attribute__((__diagnose_if__(__VA_ARGS__, "warning")))
+    __attribute__((diagnose_if(__VA_ARGS__, "warning")))
 # define _LIBCPP_DIAGNOSE_ERROR(...) \
-    __attribute__((__diagnose_if__(__VA_ARGS__, "error")))
+    __attribute__((diagnose_if(__VA_ARGS__, "error")))
 #else
 # define _LIBCPP_DIAGNOSE_WARNING(...)
 # define _LIBCPP_DIAGNOSE_ERROR(...)
diff --git a/include/atomic b/include/atomic
index 83889fb..a17bdce 100644
--- a/include/atomic
+++ b/include/atomic
@@ -560,6 +560,22 @@
 # define __cpp_lib_atomic_is_always_lock_free 201603L
 #endif
 
+#define _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) \
+  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_consume || \
+                           __m == memory_order_acquire || \
+                           __m == memory_order_acq_rel,   \
+                        "memory order argument to atomic operation is invalid")
+
+#define _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) \
+  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_release || \
+                           __m == memory_order_acq_rel,   \
+                        "memory order argument to atomic operation is invalid")
+
+#define _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__m, __f) \
+  _LIBCPP_DIAGNOSE_WARNING(__f == memory_order_release || \
+                           __f == memory_order_acq_rel,   \
+                        "memory order argument to atomic operation is invalid")
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 typedef enum memory_order
@@ -881,15 +897,19 @@
         {return static_cast<__atomic_base const volatile*>(this)->is_lock_free();}
     _LIBCPP_INLINE_VISIBILITY
     void store(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
         {__c11_atomic_store(&__a_, __d, __m);}
     _LIBCPP_INLINE_VISIBILITY
     void store(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
         {__c11_atomic_store(&__a_, __d, __m);}
     _LIBCPP_INLINE_VISIBILITY
     _Tp load(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
+      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
         {return __c11_atomic_load(&__a_, __m);}
     _LIBCPP_INLINE_VISIBILITY
     _Tp load(memory_order __m = memory_order_seq_cst) const _NOEXCEPT
+      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
         {return __c11_atomic_load(&__a_, __m);}
     _LIBCPP_INLINE_VISIBILITY
     operator _Tp() const volatile _NOEXCEPT {return load();}
@@ -904,18 +924,22 @@
     _LIBCPP_INLINE_VISIBILITY
     bool compare_exchange_weak(_Tp& __e, _Tp __d,
                                memory_order __s, memory_order __f) volatile _NOEXCEPT
+      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
         {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
     _LIBCPP_INLINE_VISIBILITY
     bool compare_exchange_weak(_Tp& __e, _Tp __d,
                                memory_order __s, memory_order __f) _NOEXCEPT
+      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
         {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
     _LIBCPP_INLINE_VISIBILITY
     bool compare_exchange_strong(_Tp& __e, _Tp __d,
                                  memory_order __s, memory_order __f) volatile _NOEXCEPT
+      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
         {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
     _LIBCPP_INLINE_VISIBILITY
     bool compare_exchange_strong(_Tp& __e, _Tp __d,
                                  memory_order __s, memory_order __f) _NOEXCEPT
+      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
         {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
     _LIBCPP_INLINE_VISIBILITY
     bool compare_exchange_weak(_Tp& __e, _Tp __d,
@@ -1181,6 +1205,7 @@
 inline _LIBCPP_INLINE_VISIBILITY
 void
 atomic_store_explicit(volatile atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
+  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
 {
     __o->store(__d, __m);
 }
@@ -1189,6 +1214,7 @@
 inline _LIBCPP_INLINE_VISIBILITY
 void
 atomic_store_explicit(atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
+  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
 {
     __o->store(__d, __m);
 }
@@ -1217,6 +1243,7 @@
 inline _LIBCPP_INLINE_VISIBILITY
 _Tp
 atomic_load_explicit(const volatile atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
+  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
 {
     return __o->load(__m);
 }
@@ -1225,6 +1252,7 @@
 inline _LIBCPP_INLINE_VISIBILITY
 _Tp
 atomic_load_explicit(const atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
+  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
 {
     return __o->load(__m);
 }
@@ -1309,6 +1337,7 @@
 atomic_compare_exchange_weak_explicit(volatile atomic<_Tp>* __o, _Tp* __e,
                                       _Tp __d,
                                       memory_order __s, memory_order __f) _NOEXCEPT
+  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
 {
     return __o->compare_exchange_weak(*__e, __d, __s, __f);
 }
@@ -1318,6 +1347,7 @@
 bool
 atomic_compare_exchange_weak_explicit(atomic<_Tp>* __o, _Tp* __e, _Tp __d,
                                       memory_order __s, memory_order __f) _NOEXCEPT
+  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
 {
     return __o->compare_exchange_weak(*__e, __d, __s, __f);
 }
@@ -1330,6 +1360,7 @@
 atomic_compare_exchange_strong_explicit(volatile atomic<_Tp>* __o,
                                         _Tp* __e, _Tp __d,
                                         memory_order __s, memory_order __f) _NOEXCEPT
+  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
 {
     return __o->compare_exchange_strong(*__e, __d, __s, __f);
 }
@@ -1340,6 +1371,7 @@
 atomic_compare_exchange_strong_explicit(atomic<_Tp>* __o, _Tp* __e,
                                         _Tp __d,
                                         memory_order __s, memory_order __f) _NOEXCEPT
+  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
 {
     return __o->compare_exchange_strong(*__e, __d, __s, __f);
 }
diff --git a/test/libcxx/atomics/diagnose_invalid_memory_order.fail.cpp b/test/libcxx/atomics/diagnose_invalid_memory_order.fail.cpp
new file mode 100644
index 0000000..d8bb363
--- /dev/null
+++ b/test/libcxx/atomics/diagnose_invalid_memory_order.fail.cpp
@@ -0,0 +1,124 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: verify-support, diagnose-if-support
+// UNSUPPORTED: libcpp-has-no-threads
+
+// <atomic>
+
+// Test that invalid memory order arguments are diagnosed where possible.
+
+#include <atomic>
+
+int main() {
+    std::atomic<int> x(42);
+    volatile std::atomic<int>& vx = x;
+    int val1 = 1; ((void)val1);
+    int val2 = 2; ((void)val2);
+    // load operations
+    {
+        x.load(std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        x.load(std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        vx.load(std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        vx.load(std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        // valid memory orders
+        x.load(std::memory_order_relaxed);
+        x.load(std::memory_order_consume);
+        x.load(std::memory_order_acquire);
+        x.load(std::memory_order_seq_cst);
+    }
+    {
+        std::atomic_load_explicit(&x, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_load_explicit(&x, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_load_explicit(&vx, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_load_explicit(&vx, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        // valid memory orders
+        std::atomic_load_explicit(&x, std::memory_order_relaxed);
+        std::atomic_load_explicit(&x, std::memory_order_consume);
+        std::atomic_load_explicit(&x, std::memory_order_acquire);
+        std::atomic_load_explicit(&x, std::memory_order_seq_cst);
+    }
+    // store operations
+    {
+        x.store(42, std::memory_order_consume); // expected-warning {{memory order argument to atomic operation is invalid}}
+        x.store(42, std::memory_order_acquire); // expected-warning {{memory order argument to atomic operation is invalid}}
+        x.store(42, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        vx.store(42, std::memory_order_consume); // expected-warning {{memory order argument to atomic operation is invalid}}
+        vx.store(42, std::memory_order_acquire); // expected-warning {{memory order argument to atomic operation is invalid}}
+        vx.store(42, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        // valid memory orders
+        x.store(42, std::memory_order_relaxed);
+        x.store(42, std::memory_order_release);
+        x.store(42, std::memory_order_seq_cst);
+    }
+    {
+        std::atomic_store_explicit(&x, 42, std::memory_order_consume); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_store_explicit(&x, 42, std::memory_order_acquire); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_store_explicit(&x, 42, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_store_explicit(&vx, 42, std::memory_order_consume); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_store_explicit(&vx, 42, std::memory_order_acquire); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_store_explicit(&vx, 42, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        // valid memory orders
+        std::atomic_store_explicit(&x, 42, std::memory_order_relaxed);
+        std::atomic_store_explicit(&x, 42, std::memory_order_release);
+        std::atomic_store_explicit(&x, 42, std::memory_order_seq_cst);
+    }
+    // compare exchange weak
+    {
+        x.compare_exchange_weak(val1, val2, std::memory_order_seq_cst, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        x.compare_exchange_weak(val1, val2, std::memory_order_seq_cst, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        vx.compare_exchange_weak(val1, val2, std::memory_order_seq_cst, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        vx.compare_exchange_weak(val1, val2, std::memory_order_seq_cst, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        // valid memory orders
+        x.compare_exchange_weak(val1, val2, std::memory_order_seq_cst, std::memory_order_relaxed);
+        x.compare_exchange_weak(val1, val2, std::memory_order_seq_cst, std::memory_order_consume);
+        x.compare_exchange_weak(val1, val2, std::memory_order_seq_cst, std::memory_order_acquire);
+        x.compare_exchange_weak(val1, val2, std::memory_order_seq_cst, std::memory_order_seq_cst);
+        // Test that the cmpxchg overload with only one memory order argument
+        // does not generate any diagnostics.
+        x.compare_exchange_weak(val1, val2, std::memory_order_release);
+    }
+    {
+        std::atomic_compare_exchange_weak_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_compare_exchange_weak_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_compare_exchange_weak_explicit(&vx, &val1, val2, std::memory_order_seq_cst, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_compare_exchange_weak_explicit(&vx, &val1, val2, std::memory_order_seq_cst, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        // valid memory orders
+        std::atomic_compare_exchange_weak_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_relaxed);
+        std::atomic_compare_exchange_weak_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_consume);
+        std::atomic_compare_exchange_weak_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_acquire);
+        std::atomic_compare_exchange_weak_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_seq_cst);
+    }
+    // compare exchange strong
+    {
+        x.compare_exchange_strong(val1, val2, std::memory_order_seq_cst, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        x.compare_exchange_strong(val1, val2, std::memory_order_seq_cst, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        vx.compare_exchange_strong(val1, val2, std::memory_order_seq_cst, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        vx.compare_exchange_strong(val1, val2, std::memory_order_seq_cst, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        // valid memory orders
+        x.compare_exchange_strong(val1, val2, std::memory_order_seq_cst, std::memory_order_relaxed);
+        x.compare_exchange_strong(val1, val2, std::memory_order_seq_cst, std::memory_order_consume);
+        x.compare_exchange_strong(val1, val2, std::memory_order_seq_cst, std::memory_order_acquire);
+        x.compare_exchange_strong(val1, val2, std::memory_order_seq_cst, std::memory_order_seq_cst);
+        // Test that the cmpxchg overload with only one memory order argument
+        // does not generate any diagnostics.
+        x.compare_exchange_strong(val1, val2, std::memory_order_release);
+    }
+    {
+        std::atomic_compare_exchange_strong_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_compare_exchange_strong_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_compare_exchange_strong_explicit(&vx, &val1, val2, std::memory_order_seq_cst, std::memory_order_release); // expected-warning {{memory order argument to atomic operation is invalid}}
+        std::atomic_compare_exchange_strong_explicit(&vx, &val1, val2, std::memory_order_seq_cst, std::memory_order_acq_rel); // expected-warning {{memory order argument to atomic operation is invalid}}
+        // valid memory orders
+        std::atomic_compare_exchange_strong_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_relaxed);
+        std::atomic_compare_exchange_strong_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_consume);
+        std::atomic_compare_exchange_strong_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_acquire);
+        std::atomic_compare_exchange_strong_explicit(&x, &val1, val2, std::memory_order_seq_cst, std::memory_order_seq_cst);
+    }
+}