misc: Fix multiple compile warnings in gcc and clang

src/xrt/auxiliary/util/u_pacing_compositor.c

@@ -609,7 +609,7 @@ pc_info(struct u_pacing_compositor *upc,
 	}
 
 	assert(f->state == STATE_SUBMITTED);
-	uint64_t unslopped_desired_present_time_ns = desired_present_time_ns + PRESENT_SLOP_NS;
+	XRT_MAYBE_UNUSED uint64_t unslopped_desired_present_time_ns = desired_present_time_ns + PRESENT_SLOP_NS;
 	assert(f->desired_present_time_ns == desired_present_time_ns ||
 	       f->desired_present_time_ns == unslopped_desired_present_time_ns);
 

src/xrt/compositor/null/null_compositor.c

@@ -586,7 +586,7 @@ null_compositor_create_system(struct xrt_device *xdev, struct xrt_system_composi
 
 	// Standard app pacer.
 	struct u_pacing_app_factory *upaf = NULL;
-	xrt_result_t xret = u_pa_factory_create(&upaf);
+	XRT_MAYBE_UNUSED xrt_result_t xret = u_pa_factory_create(&upaf);
 	assert(xret == XRT_SUCCESS && upaf != NULL);
 
 	return comp_multi_create_system_compositor(&c->base.base, upaf, &c->sys_info, false, out_xsysc);

src/xrt/drivers/vive/vive_controller.c

@@ -351,6 +351,7 @@ vive_controller_get_hand_tracking(struct xrt_device *xdev,
 	 * This only makes sense with 3dof.
 	 */
 
+#if 0
 	float pivot_offset_z = 0.15;
 
 	struct xrt_space_relation controller_relation = {
@@ -359,6 +360,7 @@ vive_controller_get_hand_tracking(struct xrt_device *xdev,
 	controller_relation.relation_flags = XRT_SPACE_RELATION_ORIENTATION_VALID_BIT |
 	                                     XRT_SPACE_RELATION_ORIENTATION_VALID_BIT |
 	                                     XRT_SPACE_RELATION_POSITION_VALID_BIT;
+#endif
 
 	struct xrt_vec3 static_offset = {0, 0, 0};
 

src/xrt/state_trackers/gui/gui_window_record.c

@@ -206,7 +206,7 @@ window_draw_misc(struct gui_record_window *rw)
 	igSameLine(0.0f, 4.0f);
 	bool plus = igButton("+", button_dims);
 
-	const static double scales[] = {
+	static const double scales[] = {
 	    25.0, 50.0, 100.0, 200.0, 300.0,
 	};
 

src/xrt/state_trackers/oxr/oxr_dpad.c

@@ -53,7 +53,7 @@ oxr_dpad_state_get_or_add(struct oxr_dpad_state *state, uint64_t key)
 	struct oxr_dpad_entry *e = oxr_dpad_state_get(state, key);
 	if (e == NULL) {
 		e = U_TYPED_CALLOC(struct oxr_dpad_entry);
-		int ret = u_hashmap_int_insert(state->uhi, key, (void *)e);
+		XRT_MAYBE_UNUSED int ret = u_hashmap_int_insert(state->uhi, key, (void *)e);
 		assert(ret >= 0);
 	}
 

src/xrt/state_trackers/oxr/oxr_session.c

@@ -1015,7 +1015,7 @@ xr_hand_to_force_feedback_output(XrHandEXT hand)
 	switch (hand) {
 	case XR_HAND_LEFT_EXT: return XRT_OUTPUT_NAME_FORCE_FEEDBACK_LEFT;
 	case XR_HAND_RIGHT_EXT: return XRT_OUTPUT_NAME_FORCE_FEEDBACK_RIGHT;
-	default: assert(false);
+	default: assert(false); return 0;
 	}
 }
 

src/xrt/state_trackers/steamvr_drv/ovrd_driver.cpp

@@ -314,7 +314,7 @@ flexion_joints_to_bone_transform(struct xrt_hand_joint_set *hand_joint_set,
 	struct xrt_hand_joint_value *joint_values = hand_joint_set->values.hand_joint_set_default;
 
 	// Apply orientations for four-finger pxm and onward
-	int parent;
+	int parent = -1;
 	for (int joint = XRT_HAND_JOINT_THUMB_METACARPAL; joint < XRT_HAND_JOINT_COUNT; joint++) {
 		if (u_hand_joint_is_metacarpal((xrt_hand_joint)joint)) {
 			parent = joint;

src/xrt/targets/sdl_test/sdl_compositor.c

@@ -601,7 +601,7 @@ sdl_compositor_create_system(struct sdl_program *sp, struct xrt_system_composito
 {
 	// Standard app pacer.
 	struct u_pacing_app_factory *upaf = NULL;
-	xrt_result_t xret = u_pa_factory_create(&upaf);
+	XRT_MAYBE_UNUSED xrt_result_t xret = u_pa_factory_create(&upaf);
 	assert(xret == XRT_SUCCESS && upaf != NULL);
 
 	return comp_multi_create_system_compositor(&sp->c.base.base, upaf, &sp->c.sys_info, false, out_xsysc);

src/xrt/tracking/hand/mercury/hg_sync.cpp

@@ -747,10 +747,6 @@ HandTracking::cCallbackProcess(struct t_hand_tracking_sync *ht_sync,
 		hgt->views[1].debug_out_to_this = debug_output(cv::Rect(view_offsets[1], view_size));
 		scribble_image_boundary(hgt);
 
-		//
-
-		struct xrt_frame *new_model_inputs_and_outputs = NULL;
-
 		// Let's check that the collage size is actually as big as we think it is
 		static_assert(720 == (kVisSpacerSize + ((kKeypointInputSize + kVisSpacerSize) * 4) +
 		                      ((kDetectionInputSize + 8))));

src/xrt/tracking/hand/mercury/kine_lm/lm_main.cpp

@@ -184,7 +184,7 @@ eval_hand_set_rel_orientations(const OptimizerHand<T> &opt, Orientations54<T> &r
 // Thumb MCP hidden orientation
 #if 0
 	Vec2<T> mcp_root_swing;
-	
+
 	mcp_root_swing.x = rad<T>((T)(-10));
 	mcp_root_swing.y = rad<T>((T)(-40));
 
@@ -544,7 +544,7 @@ CostFunctor<optimize_hand_size>::operator()(const T *const x, T *residual) const
 // When you're hacking, you want to set the residuals to always-0 so that any of them you forget to touch keep their 0
 // gradient.
 // But then later this just becomes a waste.
-#if 0	
+#if 0
 	for (size_t i = 0; i < residual_size; i++) {
 		residual[i] = (T)(0);
 	}
@@ -848,7 +848,7 @@ opt_run(KinematicHandLM &state, one_frame_input &observation, xrt_hand_joint_set
 		uint64_t diff = end - start;
 		double time_taken = (double)diff / (double)U_TIME_1MS_IN_NS;
 
-		const char *status;
+		const char *status = "UNDEFINED";
 
 		switch (summary.status) {
 		case 0: {