From f2b7d44772aaf2932db2936c49228775c7bf6593 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Sun, 6 Jun 2021 10:51:03 +1000
Subject: [PATCH] AP_Compass: fixed build with AP_Periph compass

---
 libraries/AP_Compass/AP_Compass.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libraries/AP_Compass/AP_Compass.cpp b/libraries/AP_Compass/AP_Compass.cpp
index 2f6737f7b0..77ac477eaa 100644
--- a/libraries/AP_Compass/AP_Compass.cpp
+++ b/libraries/AP_Compass/AP_Compass.cpp
@@ -1440,12 +1440,14 @@ bool Compass::is_replacement_mag(uint32_t devid) {
         return false;
     }
 
+#if COMPASS_MAX_UNREG_DEV > 0
     // Check that its not an unused additional mag
     for (uint8_t i = 0; i<COMPASS_MAX_UNREG_DEV; i++) {
         if (_previously_unreg_mag[i] == devid) {
             return false;
         }
     }
+#endif
 
     // Check that its not previously setup mag
     for (StateIndex i(0); i<COMPASS_MAX_INSTANCES; i++) {
@@ -1465,6 +1467,7 @@ void Compass::remove_unreg_dev_id(uint32_t devid)
         return;
     }
 
+#if COMPASS_MAX_UNREG_DEV > 0
     for (uint8_t i = 0; i<COMPASS_MAX_UNREG_DEV; i++) {
         if ((uint32_t)extra_dev_id[i] == devid) {
             extra_dev_id[i].set_and_save(0);
@@ -1472,6 +1475,7 @@ void Compass::remove_unreg_dev_id(uint32_t devid)
         }
     }
 #endif
+#endif
 }
 
 void Compass::_reset_compass_id()
@@ -1486,7 +1490,7 @@ void Compass::_reset_compass_id()
         }
         if (!_get_state(i).registered) {
             _priority_did_stored_list[i].set_and_save(0);
-            gcs().send_text(MAV_SEVERITY_ALERT, "Mag: Compass #%d with DEVID %lu removed", uint8_t(i), (unsigned long)_priority_did_list[i]);
+            GCS_SEND_TEXT(MAV_SEVERITY_ALERT, "Mag: Compass #%d with DEVID %lu removed", uint8_t(i), (unsigned long)_priority_did_list[i]);
         }
     }