Fix MAP_JIT issues on Mac. Patch by Carlo Arenas.

git-svn-id: svn:https://vcs.exim.org/pcre/code/trunk@1743 2f5784b3-3f2a-0410-8824-cb99058d5e15

sljit/sljitExecAllocator.c

@@ -96,32 +96,31 @@ static SLJIT_INLINE void free_chunk(void *chunk, sljit_uw size)
 
 #ifdef MAP_JIT
 
+#ifdef __APPLE__
+#include <sys/utsname.h>
+#endif /* __APPLE__ */
+
 static SLJIT_INLINE int get_map_jit_flag()
 {
-#ifdef TARGET_OS_MAC
+#ifdef __APPLE__
  /* On macOS systems, returns MAP_JIT if it is defined _and_ we're running on a version
  of macOS where it's OK to have more than one JIT block. On non-macOS systems, returns
  MAP_JIT if it is defined. */
+ static int map_jit_flag = -1;
 
- static dispatch_once_t _inited;
- static int map_jit_flag;
-
- dispatch_once(&_inited,
- ^() {
- struct utsname name;
+ if (map_jit_flag == -1) {
+ struct utsname name;
 
-  uname(&name);
+ uname(&name);
 
- /* Kernel version for 10.14.0 (Mojave) */
- if (atoi(name.release) >= 18)
- map_jit_flag = MAP_JIT;
- }
- );
+ /* Kernel version for 10.14.0 (Mojave) */
+ map_jit_flag = (atoi(name.release) >= 18) ? MAP_JIT : 0;
+ }
 
  return map_jit_flag;
-#else /* !TARGET_OS_MAC */
+#else /* !__APPLE__ */
  return MAP_JIT;
-#endif /* TARGET_OS_MAC */
+#endif /* __APPLE__ */
 }
 
 #endif /* MAP_JIT */