Hide symbols via compilerflag

Makefile

@@ -34,4 +34,4 @@ TEMPLATES += db/turboPmac.db
 DBDS += sinqMotor/src/sinqMotor.dbd
 DBDS += src/turboPmac.dbd
 
-USR_CFLAGS += -Wall -Wextra -Weffc++ -Wunused-result -Werror # -Wpedantic // Does not work because EPICS macros trigger warnings
+USR_CFLAGS += -Wall -Wextra -Weffc++ -Wunused-result -Werror -fvisibility=hidden # -Wpedantic // Does not work because EPICS macros trigger warnings

src/turboPmacController.h

@@ -93,7 +93,8 @@ class turboPmacController : public sinqController {
      * @return asynStatus
      */
     asynStatus writeRead(int axisNo, const char *command, char *response,
-                         int numExpectedResponses);
+                         int numExpectedResponses)
+        __attribute__((visibility("hidden")));
 
     /**
      * @brief Specialized version of sinqController::couldNotParseResponse