eal: fix build of external app with clang on armv8

In case DPDK built using GCC, RTE_TOOLCHAIN_CLANG is not defined.
But 'rte_atomic.h' is a generic header that included to the
external apps like OVS while building with DPDK. As a result,
clang build of OVS fails on armv8 if DPDK built using gcc:

    include/generic/rte_atomic.h:215:9: error:
            implicit declaration of function '__atomic_exchange_2'
            is invalid in C99
    include/generic/rte_atomic.h:494:9: error:
            implicit declaration of function '__atomic_exchange_4'
            is invalid in C99
    include/generic/rte_atomic.h:772:9: error:
            implicit declaration of function '__atomic_exchange_8'
            is invalid in C99

We need to check for current compiler, not the compiler used for
DPDK build.

Fixes: 7bdccb93078e ("eal: fix ARM build with clang")
Cc: stable@dpdk.org
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>

diff --git a/lib/librte_eal/common/include/generic/rte_atomic.h b/lib/librte_eal/common/include/generic/rte_atomic.h
index b99ba46..d0c464f 100644 (file)
--- a/lib/librte_eal/common/include/generic/rte_atomic.h
+++ b/lib/librte_eal/common/include/generic/rte_atomic.h
@@ -212,7 +212,7 @@ rte_atomic16_exchange(volatile uint16_t *dst, uint16_t val);
 static inline uint16_t
 rte_atomic16_exchange(volatile uint16_t *dst, uint16_t val)
 {
-#if defined(RTE_ARCH_ARM64) && defined(RTE_TOOLCHAIN_CLANG)
+#if defined(RTE_ARCH_ARM64) && defined(__clang__)
        return __atomic_exchange_n(dst, val, __ATOMIC_SEQ_CST);
 #else
        return __atomic_exchange_2(dst, val, __ATOMIC_SEQ_CST);
@@ -495,7 +495,7 @@ rte_atomic32_exchange(volatile uint32_t *dst, uint32_t val);
 static inline uint32_t
 rte_atomic32_exchange(volatile uint32_t *dst, uint32_t val)
 {
-#if defined(RTE_ARCH_ARM64) && defined(RTE_TOOLCHAIN_CLANG)
+#if defined(RTE_ARCH_ARM64) && defined(__clang__)
        return __atomic_exchange_n(dst, val, __ATOMIC_SEQ_CST);
 #else
        return __atomic_exchange_4(dst, val, __ATOMIC_SEQ_CST);
@@ -777,7 +777,7 @@ rte_atomic64_exchange(volatile uint64_t *dst, uint64_t val);
 static inline uint64_t
 rte_atomic64_exchange(volatile uint64_t *dst, uint64_t val)
 {
-#if defined(RTE_ARCH_ARM64) && defined(RTE_TOOLCHAIN_CLANG)
+#if defined(RTE_ARCH_ARM64) && defined(__clang__)
        return __atomic_exchange_n(dst, val, __ATOMIC_SEQ_CST);
 #else
        return __atomic_exchange_8(dst, val, __ATOMIC_SEQ_CST);