common: correct storage class attributes in render.h

Towards https://gitlab.com/graphviz/graphviz/-/issues/2058.

diff --git a/lib/common/render.h b/lib/common/render.h
index 64b8def6ff175d761647627b0b69d9ce713cc2da..9746ba2a5ce890baef8ee78f3628212f072dae6f 100644 (file)
--- a/lib/common/render.h
+++ b/lib/common/render.h
@@ -54,15 +54,16 @@ extern "C" {
        point offset;
     } epsf_t;
 
-/*visual studio*/
-#ifdef _WIN32
-#ifndef GVC_EXPORTS
+#ifdef GVDLL
+#ifdef GVC_EXPORTS
+#define RENDER_API __declspec(dllexport)
+#else
 #define RENDER_API __declspec(dllimport)
 #endif
 #endif
-/*end visual studio*/
+
 #ifndef RENDER_API
-#define RENDER_API extern
+#define RENDER_API /* nothing */
 #endif
 
        RENDER_API void add_box(path *, boxf);