make export cross platforms (#464)

Author: c8ef

async_simple/CommonMacros.h

@@ -31,6 +31,12 @@
 #define AS_INLINE __attribute__((__always_inline__)) inline
 #endif
 
+#ifdef _WIN32
+#define AS_EXPORT __declspec(dllexport)
+#else
+#define AS_EXPORT __attribute__((__visibility__("default")))
+#endif
+
 #ifdef __clang__
 #if __has_feature(address_sanitizer)
 #define AS_INTERNAL_USE_ASAN 1

async_simple/uthread/internal/thread_impl.h

@@ -37,10 +37,10 @@ struct transfer_t {
     fcontext_t fctx;
     void* data;
 };
-extern "C" __attribute__((__visibility__("default"))) transfer_t
-_fl_jump_fcontext(fcontext_t const to, void* vp);
-extern "C" __attribute__((__visibility__("default"))) fcontext_t
-_fl_make_fcontext(void* sp, std::size_t size, void (*fn)(transfer_t));
+extern "C" AS_EXPORT transfer_t _fl_jump_fcontext(fcontext_t const to,
+                                                  void* vp);
+extern "C" AS_EXPORT fcontext_t _fl_make_fcontext(void* sp, std::size_t size,
+                                                  void (*fn)(transfer_t));
 
 class thread_context;