glapi: Make _GLAPI_EXPORT a no-op on Windows.

DLL import/export annotations unneeded, now that glapi is statically
linked into libgallium_wgl.

However _mesa_glapi_get_proc_address and _mesa_glapi_get_dispatch need
to be explicitly exported for libEGL and libGLESv2.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/12573
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33822>

src/gallium/targets/libgl-gdi/meson.build

@@ -18,7 +18,7 @@ libopengl32 = shared_library(
     inc_include, inc_wgl, inc_src, inc_gallium,
   ],
   link_with : [
-    libgallium_wgl, libglapi_bridge, libglapi
+    libgallium_wgl, libglapi_bridge
   ],
   dependencies : [
     idep_mesautil

src/gallium/targets/wgl/gallium_wgl.def.in

@@ -50,3 +50,6 @@ stw_get_config_xml
 stw_interop_query_device_info
 stw_interop_export_object
 stw_interop_flush_objects
+
+_mesa_glapi_get_proc_address
+_mesa_glapi_get_dispatch

src/mapi/glapi/glapi.h

@@ -54,21 +54,13 @@ extern "C" {
 #endif
 
 
-#ifdef _GLAPI_NO_EXPORTS
+#ifdef _WIN32
 #  define _GLAPI_EXPORT
-#else /* _GLAPI_NO_EXPORTS */
-#  ifdef _WIN32
-#    ifdef _GLAPI_DLL_EXPORTS
-#      define _GLAPI_EXPORT __declspec(dllexport)
-#    else
-#      define _GLAPI_EXPORT __declspec(dllimport)
-#    endif
-#  elif defined(__GNUC__)
-#    define _GLAPI_EXPORT __attribute__((visibility("default")))
-#  else
-#    define _GLAPI_EXPORT
-#  endif
-#endif /* _GLAPI_NO_EXPORTS */
+#elif defined(__GNUC__)
+#  define _GLAPI_EXPORT __attribute__((visibility("default")))
+#else
+#  define _GLAPI_EXPORT
+#endif
 
 
 typedef void (*_glapi_proc)(void);

src/mapi/shared-glapi/meson.build

@@ -20,16 +20,10 @@ shared_glapi_mapi_tmp_h = custom_target(
   capture : true,
 )
 
-_glapi_c_args = []
-if with_platform_windows
-  _glapi_c_args += ['-D_GLAPI_DLL_EXPORTS']
-endif
-
 libglapi = static_library(
   'glapi',
   [files_shared_glapi, shared_glapi_mapi_tmp_h],
   c_args : [
-    _glapi_c_args,
     c_msvc_compat_args,
     '-DMAPI_MODE_GLAPI',
     '-DMAPI_ABI_HEADER="@0@"'.format(shared_glapi_mapi_tmp_h.full_path()),

src/mesa/meson.build

@@ -443,7 +443,6 @@ endif
 _mesa_windows_args = []
 if with_platform_windows
   _mesa_windows_args += [
-    '-D_GLAPI_NO_EXPORTS',
     '-D_GDI32_',    # prevent gl* being declared __declspec(dllimport) in MS headers
   ]
 endif