common: correct storage-class attribute declarations in utils.h

This will allow removing the utils.h symbols from the gvc.def file in
an upcoming commit.

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

diff --git a/lib/common/utils.h b/lib/common/utils.h
index 61bc6816db9d87a4e14b856a77fdf249c0398ff0..11ddc63665a0276a58664c970899592fc42e4da0 100644 (file)
--- a/lib/common/utils.h
+++ b/lib/common/utils.h
@@ -19,15 +19,16 @@
 extern "C" {
 #endif
 
-/*visual studio*/
-#ifdef _WIN32
-#ifndef GVC_EXPORTS
+#ifdef GVDLL
+#ifdef GVC_EXPORTS
+#define UTILS_API __declspec(dllexport)
+#else
 #define UTILS_API __declspec(dllimport)
 #endif
 #endif
-/*end visual studio*/
+
 #ifndef UTILS_API
-#define UTILS_API extern
+#define UTILS_API /* nothing */
 #endif
 
 // options to tweak the behavior of XML escaping