add stdatomic.h for gcc-4.8.5

CMakeLists.txt

@@ -22,6 +22,7 @@ option(MI_BUILD_TESTS       "Build test executables" ON)
 option(MI_DEBUG_TSAN        "Build with thread sanitizer (needs clang)" OFF)
 option(MI_DEBUG_UBSAN       "Build with undefined-behavior sanitizer (needs clang++)" OFF)
 option(MI_SKIP_COLLECT_ON_EXIT, "Skip collecting memory on program exit" OFF)
+option(MI_ATOMIC_FOR_GCC485 "Build with custom stdatomic.h for gcc-4.8.5" OFF)
 
 # deprecated options
 option(MI_CHECK_FULL        "Use full internal invariant checking in DEBUG mode (deprecated, use MI_DEBUG_FULL instead)" OFF)
@@ -143,6 +144,11 @@ if(MI_SHOW_ERRORS)
   list(APPEND mi_defines MI_SHOW_ERRORS=1)
 endif()
 
+if(MI_ATOMIC_FOR_GCC485)
+  message(STATUS "Enable using cumstom stdatomic.h file for gcc 4.8.5 (MI_ATOMIC_FOR_GCC485=ON)")
+  list(APPEND mi_defines MI_ATOMIC_FOR_GCC485=1)
+endif()
+
 if(MI_DEBUG_TSAN)
   if(CMAKE_C_COMPILER_ID MATCHES "Clang")
     message(STATUS "Build with thread sanitizer (MI_DEBUG_TSAN=ON)")

include/gcc-4.8.5-atomic.h

@@ -0,0 +1,43 @@
+/**
+ * @file gcc-4.8.5-atomic.h
+ *
+ * @author shadow-yuan (shadow_yuan@qq.com)
+ *
+ * @brief because gcc-4.8.5 does not include the file stdatomic.h
+ *       so add this file to pass the compilation
+ *
+ */
+#ifndef MI_FOR_GCC_485_ATOMIC_H_
+#define MI_FOR_GCC_485_ATOMIC_H_
+
+#define memory_order_relaxed __ATOMIC_RELAXED
+#define memory_order_consume __ATOMIC_CONSUME
+#define memory_order_acquire __ATOMIC_ACQUIRE
+#define memory_order_release __ATOMIC_RELEASE
+#define memory_order_acq_rel __ATOMIC_ACQ_REL
+#define memory_order_seq_cst __ATOMIC_SEQ_CST
+
+#define _Atomic(x) x
+
+#define __has_include(x) (1)
+
+#define atomic_load_explicit(p, m)     __atomic_load_n(p, m)
+#define atomic_store_explicit(p, x, m) __atomic_store_n(p, x, m)
+
+#define atomic_exchange(p, x)             __atomic_exchange_n(p, x, memory_order_seq_cst)
+#define atomic_exchange_explicit(p, x, m) __atomic_exchange_n(p, x, m)
+
+#define atomic_compare_exchange_weak_explicit(p, expected, desired, mem_success, mem_fail)         \
+    __atomic_compare_exchange_n(p, expected, desired, 1, mem_success, mem_fail)
+
+#define atomic_compare_exchange_strong_explicit(p, expected, desired, mem_success, mem_fail)       \
+    __atomic_compare_exchange_n(p, expected, desired, 0, mem_success, mem_fail)
+
+#define atomic_fetch_add_explicit(p, x, m) __atomic_fetch_add(p, x, m)
+#define atomic_fetch_sub_explicit(p, x, m) __atomic_fetch_sub(p, x, m)
+#define atomic_fetch_and_explicit(p, x, m) __atomic_fetch_and(p, x, m)
+#define atomic_fetch_or_explicit(p, x, m)  __atomic_fetch_or(p, x, m)
+
+#define ATOMIC_VAR_INIT(x) (x)
+
+#endif // MI_FOR_GCC_485_ATOMIC_H_

include/mimalloc-atomic.h

@@ -34,6 +34,11 @@ terms of the MIT license. A copy of the license can be found in the file
 #define  MI_ATOMIC_VAR_INIT(x)  x
 #define  mi_atomic(name)        mi_atomic_##name
 #define  mi_memory_order(name)  mi_memory_order_##name
+#elif defined(MI_ATOMIC_FOR_GCC485)
+#include <gcc-4.8.5-atomic.h>
+#define  mi_atomic(name)        atomic_##name
+#define  mi_memory_order(name)  memory_order_##name
+#define  MI_ATOMIC_VAR_INIT(x)  x
 #else
 // Use C11 atomics
 #include <stdatomic.h>

test/test-stress.c

@@ -336,7 +336,11 @@ static void* atomic_exchange_ptr(volatile void** p, void* newval) {
   return std::atomic_exchange((volatile std::atomic<void*>*)p, newval);
 }
 #else
+#if defined(MI_ATOMIC_FOR_GCC485)
+#include <gcc-4.8.5-atomic.h>
+#else
 #include <stdatomic.h>
+#endif
 static void* atomic_exchange_ptr(volatile void** p, void* newval) {
   return atomic_exchange((volatile _Atomic(void*)*)p, newval);
 }