ovs-atomic: Add native Clang implementation.

With this implementation I get warnings with Clang on GNU/Linux when the
previous patch is not applied.  This ought to make it easier to avoid
introducing new problems in the future even without building on FreeBSD.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>

1 files changed, 115 insertions, 0 deletions

diff --git a/lib/ovs-atomic-clang.h b/lib/ovs-atomic-clang.h
new file mode 100644
index 00000000..dbec9569
--- /dev/null
+++ b/lib/ovs-atomic-clang.h
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2013 Nicira, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* This header implements atomic operation primitives on Clang. */
+#ifndef IN_OVS_ATOMIC_H
+#error "This header should only be included indirectly via ovs-atomic.h."
+#endif
+
+#define OVS_ATOMIC_CLANG_IMPL 1
+
+/* Standard atomic types. */
+typedef _Atomic(_Bool) atomic_bool;
+
+typedef _Atomic(char) atomic_char;
+typedef _Atomic(signed char) atomic_schar;
+typedef _Atomic(unsigned char) atomic_uchar;
+
+typedef _Atomic(short) atomic_short;
+typedef _Atomic(unsigned short) atomic_ushort;
+
+typedef _Atomic(int) atomic_int;
+typedef _Atomic(unsigned int) atomic_uint;
+
+typedef _Atomic(long) atomic_long;
+typedef _Atomic(unsigned long) atomic_ulong;
+
+typedef _Atomic(long long) atomic_llong;
+typedef _Atomic(unsigned long long) atomic_ullong;
+
+typedef _Atomic(size_t) atomic_size_t;
+typedef _Atomic(ptrdiff_t) atomic_ptrdiff_t;
+
+typedef _Atomic(intmax_t) atomic_intmax_t;
+typedef _Atomic(uintmax_t) atomic_uintmax_t;
+
+typedef _Atomic(intptr_t) atomic_intptr_t;
+typedef _Atomic(uintptr_t) atomic_uintptr_t;
+
+/* Nonstandard atomic types. */
+typedef _Atomic(uint8_t)   atomic_uint8_t;
+typedef _Atomic(uint16_t)  atomic_uint16_t;
+typedef _Atomic(uint32_t)  atomic_uint32_t;
+typedef _Atomic(uint64_t)  atomic_uint64_t;
+
+typedef _Atomic(int8_t)    atomic_int8_t;
+typedef _Atomic(int16_t)   atomic_int16_t;
+typedef _Atomic(int32_t)   atomic_int32_t;
+typedef _Atomic(int64_t)   atomic_int64_t;
+
+#define ATOMIC_VAR_INIT(VALUE) (VALUE)
+
+#define atomic_init(OBJECT, VALUE) __c11_atomic_init(OBJECT, VALUE)
+
+/* Clang hard-codes these exact values internally but does not appear to
+ * export any names for them. */
+typedef enum {
+    memory_order_relaxed = 0,
+    memory_order_consume = 1,
+    memory_order_acquire = 2,
+    memory_order_release = 3,
+    memory_order_acq_rel = 4,
+    memory_order_seq_cst = 5
+} memory_order;
+
+#define atomic_thread_fence(ORDER) __c11_atomic_thread_fence(ORDER)
+#define atomic_signal_fence(ORDER) __c11_atomic_signal_fence(ORDER)
+
+#define atomic_store(DST, SRC) \
+    atomic_store_explicit(DST, SRC, memory_order_seq_cst)
+#define atomic_store_explicit(DST, SRC, ORDER) \
+    __c11_atomic_store(DST, SRC, ORDER)
+
+
+#define atomic_read(SRC, DST) \
+    atomic_read_explicit(SRC, DST, memory_order_seq_cst)
+#define atomic_read_explicit(SRC, DST, ORDER)   \
+    (*(DST) = __c11_atomic_load(SRC, ORDER), \
+     (void) 0)
+
+#define atomic_add(RMW, ARG, ORIG) \
+    atomic_add_explicit(RMW, ARG, ORIG, memory_order_seq_cst)
+#define atomic_sub(RMW, ARG, ORIG) \
+    atomic_sub_explicit(RMW, ARG, ORIG, memory_order_seq_cst)
+#define atomic_or(RMW, ARG, ORIG) \
+    atomic_or_explicit(RMW, ARG, ORIG, memory_order_seq_cst)
+#define atomic_xor(RMW, ARG, ORIG) \
+    atomic_xor_explicit(RMW, ARG, ORIG, memory_order_seq_cst)
+#define atomic_and(RMW, ARG, ORIG) \
+    atomic_and_explicit(RMW, ARG, ORIG, memory_order_seq_cst)
+
+#define atomic_add_explicit(RMW, ARG, ORIG, ORDER) \
+    (*(ORIG) = __c11_atomic_fetch_add(RMW, ARG, ORDER), (void) 0)
+#define atomic_sub_explicit(RMW, ARG, ORIG, ORDER) \
+    (*(ORIG) = __c11_atomic_fetch_sub(RMW, ARG, ORDER), (void) 0)
+#define atomic_or_explicit(RMW, ARG, ORIG, ORDER) \
+    (*(ORIG) = __c11_atomic_fetch_or(RMW, ARG, ORDER), (void) 0)
+#define atomic_xor_explicit(RMW, ARG, ORIG, ORDER) \
+    (*(ORIG) = __c11_atomic_fetch_xor(RMW, ARG, ORDER), (void) 0)
+#define atomic_and_explicit(RMW, ARG, ORIG, ORDER) \
+    (*(ORIG) = __c11_atomic_fetch_and(RMW, ARG, ORDER), (void) 0)
+
+#include "ovs-atomic-flag-gcc4.7+.h"