[PATCH v4] Add pragma to ignore gcc-compat warnings in clang when used with diagnose_if.

[Michael Barker <mikeb01@gmail.com>]

When compiling with clang using -Wall (or -Wgcc-compat) the use of
diagnose_if kicks up a warning:

.../include/rte_interrupts.h:623:1: error: 'diagnose_if' is a clang
extension [-Werror,-Wgcc-compat]
__rte_internal
^
.../include/rte_compat.h:36:16: note: expanded from macro '__rte_internal'
__attribute__((diagnose_if(1, "Symbol is not public ABI", "error"), \

This change ignores the '-Wgcc-compat' warning in the specific location
where the warning occurs.  It is safe to do in this circumstance as the
specific macro is only defined when using the clang compiler.

Signed-off-by: Michael Barker <mikeb01@gmail.com>
---
 lib/eal/include/rte_compat.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/eal/include/rte_compat.h b/lib/eal/include/rte_compat.h
index 2718612cce..9556bbf4d0 100644
--- a/lib/eal/include/rte_compat.h
+++ b/lib/eal/include/rte_compat.h
@@ -33,8 +33,11 @@ section(".text.internal")))
 #elif !defined ALLOW_INTERNAL_API && __has_attribute(diagnose_if) /* For clang */
 
 #define __rte_internal \
+_Pragma("GCC diagnostic push") \
+_Pragma("GCC diagnostic ignored \"-Wgcc-compat\"") \
 __attribute__((diagnose_if(1, "Symbol is not public ABI", "error"), \
-section(".text.internal")))
+section(".text.internal"))) \
+_Pragma("GCC diagnostic pop")
 
 #else
 
-- 
2.25.1