--- a/gegl/graph/gegl-region-generic.c	
+++ a/gegl/graph/gegl-region-generic.c	
@@ -910,7 +910,7 @@ miRegionOp (GeglRegion       *newReg,
           top = MAX (r1->y1, ybot);
           bot = MIN (r1->y2, r2->y1);
 
-          if ((top != bot) && (nonOverlap1Fn != (void (*)())NULL))
+          if ((top != bot) && (nonOverlap1Fn != (void (*)(void))NULL))
             {
               (*nonOverlap1Fn)(newReg, r1, r1BandEnd, top, bot);
             }
@@ -922,7 +922,7 @@ miRegionOp (GeglRegion       *newReg,
           top = MAX (r2->y1, ybot);
           bot = MIN (r2->y2, r1->y1);
 
-          if ((top != bot) && (nonOverlap2Fn != (void (*)())NULL))
+          if ((top != bot) && (nonOverlap2Fn != (void (*)(void))NULL))
             {
               (*nonOverlap2Fn)(newReg, r2, r2BandEnd, top, bot);
             }
--- a/operations/common/ctx/ctx.h	
+++ a/operations/common/ctx/ctx.h	
@@ -6047,7 +6047,6 @@ int _ctx_is_rasterizer (Ctx *ctx);
 
 int ctx_color (Ctx *ctx, const char *string);
 typedef struct _CtxState CtxState;
-CtxColor *ctx_color_new ();
 CtxState *ctx_get_state (Ctx *ctx);
 void ctx_color_get_rgba (CtxState *state, CtxColor *color, float *out);
 void ctx_color_set_rgba (CtxState *state, CtxColor *color, float r, float g, float b, float a);
@@ -11081,7 +11080,6 @@ static void
 ctx_matrix_set (CtxMatrix *matrix, float a, float b, float c, float d, float e, float f, float g, float h, float i);
 
 
-static void ctx_font_setup ();
 static float ctx_state_get (CtxState *state, uint32_t hash);
 
 #if CTX_RASTERIZER
@@ -40708,9 +40706,9 @@ static void ctx_events_deinit (Ctx *ctx)
 #if CTX_TERMINAL_EVENTS
 
 
-static int mice_has_event ();
-static char *mice_get_event ();
-static void mice_destroy ();
+static int mice_has_event (void);
+static char *mice_get_event (void);
+static void mice_destroy (void);
 static int mice_get_fd (EvSource *ev_source);
 static void mice_set_coord (EvSource *ev_source, double x, double y);
 
@@ -40759,13 +40757,13 @@ static int mmm_evsource_mice_init ()
   return 0;
 }
 
-static void mice_destroy ()
+static void mice_destroy (void)
 {
   if (mrg_mice_this->fd != -1)
     close (mrg_mice_this->fd);
 }
 
-static int mice_has_event ()
+static int mice_has_event (void)
 {
   struct timeval tv;
   int retval;
@@ -40783,7 +40781,7 @@ static int mice_has_event ()
   return 0;
 }
 
-static char *mice_get_event ()
+static char *mice_get_event (void)
 {
   const char *ret = "pm";
   double relx, rely;