Subsurf: Show error when Blender is built without OpenSubdiv

source/blender/modifiers/CMakeLists.txt

@@ -141,6 +141,10 @@ if(WITH_MOD_OCEANSIM)
   add_definitions(-DWITH_OCEANSIM)
 endif()
 
+if(WITH_OPENSUBDIV)
+  add_definitions(-DWITH_OPENSUBDIV)
+endif()
+
 if(WITH_BULLET)
   list(APPEND LIB
     extern_bullet

source/blender/modifiers/intern/MOD_multires.c

@@ -168,6 +168,10 @@ static Mesh *multires_as_ccg(MultiresModifierData *mmd,
 static Mesh *applyModifier(ModifierData *md, const ModifierEvalContext *ctx, Mesh *mesh)
 {
   Mesh *result = mesh;
+#if !defined(WITH_OPENSUBDIV)
+  modifier_setError(md, "Disabled, built without OpenSubdiv");
+  return result;
+#endif
   MultiresModifierData *mmd = (MultiresModifierData *)md;
   SubdivSettings subdiv_settings;
   BKE_multires_subdiv_settings_init(&subdiv_settings, mmd);

source/blender/modifiers/intern/MOD_subsurf.c

@@ -208,6 +208,10 @@ static SubsurfRuntimeData *subsurf_ensure_runtime(SubsurfModifierData *smd)
 static Mesh *applyModifier(ModifierData *md, const ModifierEvalContext *ctx, Mesh *mesh)
 {
   Mesh *result = mesh;
+#if !defined(WITH_OPENSUBDIV)
+  modifier_setError(md, "Disabled, built without OpenSubdiv");
+  return result;
+#endif
   SubsurfModifierData *smd = (SubsurfModifierData *)md;
   SubdivSettings subdiv_settings;
   subdiv_settings_init(&subdiv_settings, smd);