InteractiveEditorX11Guard.hpp

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#ifndef INTERACTIVEEDITORX11GUARD_H
#define INTERACTIVEEDITORX11GUARD_H
 
#include <Rtypes.h>
#include <dlfcn.h>


typedef int (*AUXErrorHandler)(void *display, void *event);

typedef AUXErrorHandler (*AUXSetErrorHandlerFn)(AUXErrorHandler);

inline int AUIgnoreXError(void *, void *) { return 0; }

struct AUXErrorHandlerSave {
  AUXSetErrorHandlerFn set_fn;
  AUXErrorHandler prev;
};

inline AUXErrorHandlerSave AUInstallTolerantXErrorHandler() {
  AUXErrorHandlerSave s;
  s.set_fn = (AUXSetErrorHandlerFn)dlsym(RTLD_DEFAULT, "XSetErrorHandler");
  if (!s.set_fn) {
    // libX11 may have been brought in with local scope; promote and retry.
    void *h = dlopen("libX11.so.6", RTLD_NOW | RTLD_GLOBAL | RTLD_NOLOAD);
    if (h) {
      s.set_fn = (AUXSetErrorHandlerFn)dlsym(h, "XSetErrorHandler");
    }
  }
  s.prev = s.set_fn ? s.set_fn(AUIgnoreXError) : (AUXErrorHandler)0;
  return s;
}

inline void AURestoreXErrorHandler(AUXErrorHandlerSave s) {
  if (s.set_fn) {
    s.set_fn(s.prev);
  }
}
 
#endif