Author: Vicențiu Ciorbaru <vicentiu@mariadb.org>
Date:   Fri Dec 21 19:14:04 2018 +0200

   Link with libatomic to enable C11 atomics support

   Some architectures (mips) require libatomic to support proper
   atomic operations. Check first if support is available without
   linking, otherwise use the library.

Upstream-Status: Pending
Signed-off-by: Khem Raj <raj.khem@gmail.com>

--- a/configure.cmake
+++ b/configure.cmake
@@ -926,7 +926,25 @@ int main()
   long long int *ptr= &var;
   return (int)__atomic_load_n(ptr, __ATOMIC_SEQ_CST);
 }"
-HAVE_GCC_C11_ATOMICS)
+HAVE_GCC_C11_ATOMICS_WITHOUT_LIBATOMIC)
+IF (HAVE_GCC_C11_ATOMICS_WITHOUT_LIBATOMIC)
+  SET(HAVE_GCC_C11_ATOMICS True)
+ELSE()
+  SET(OLD_CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
+  LIST(APPEND CMAKE_REQUIRED_LIBRARIES "atomic")
+  CHECK_CXX_SOURCE_COMPILES("
+  int main()
+  {
+    long long int var= 1;
+    long long int *ptr= &var;
+    return (int)__atomic_load_n(ptr, __ATOMIC_SEQ_CST);
+  }"
+  HAVE_GCC_C11_ATOMICS_WITH_LIBATOMIC)
+  IF(HAVE_GCC_C11_ATOMICS_WITH_LIBATOMIC)
+    SET(HAVE_GCC_C11_ATOMICS True)
+  ENDIF()
+  SET(CMAKE_REQUIRED_LIBRARIES ${OLD_CMAKE_REQUIRED_LIBRARIES})
+ENDIF()
 
 IF(WITH_VALGRIND)
   SET(HAVE_valgrind 1)
--- a/mysys/CMakeLists.txt
+++ b/mysys/CMakeLists.txt
@@ -78,6 +78,10 @@ TARGET_LINK_LIBRARIES(mysys dbug strings
  ${LIBNSL} ${LIBM} ${LIBRT} ${LIBDL} ${LIBSOCKET} ${LIBEXECINFO} ${CRC32_LIBRARY})
 DTRACE_INSTRUMENT(mysys)
 
+IF (HAVE_GCC_C11_ATOMICS_WITH_LIBATOMIC)
+  TARGET_LINK_LIBRARIES(mysys atomic)
+ENDIF()
+
 IF(HAVE_BFD_H)
   TARGET_LINK_LIBRARIES(mysys bfd)  
 ENDIF(HAVE_BFD_H)
--- a/sql/CMakeLists.txt
+++ b/sql/CMakeLists.txt
@@ -178,6 +178,10 @@ ELSE()
   SET(MYSQLD_SOURCE main.cc ${DTRACE_PROBES_ALL})
 ENDIF()
 
+IF (HAVE_GCC_C11_ATOMICS_WITH_LIBATOMIC)
+  TARGET_LINK_LIBRARIES(sql atomic)
+ENDIF()
+
 
 IF(MSVC AND NOT WITHOUT_DYNAMIC_PLUGINS)