Make enums into implicit char

Marlin/enum.h

@@ -33,8 +33,7 @@
  *  - X_HEAD and Y_HEAD is used for systems that don't have a 1:1 relationship
  *    between X_AXIS and X Head movement, like CoreXY bots
  */
-enum AxisEnum {
-  NO_AXIS   = -1,
+enum AxisEnum : unsigned char {
   X_AXIS    = 0,
   A_AXIS    = 0,
   Y_AXIS    = 1,
@@ -45,7 +44,8 @@ enum AxisEnum {
   X_HEAD    = 4,
   Y_HEAD    = 5,
   Z_HEAD    = 6,
-  ALL_AXES  = 100
+  ALL_AXES  = 0xFE,
+  NO_AXIS   = 0xFF
 };
 
 #define LOOP_S_LE_N(VAR, S, N) for (uint8_t VAR=S; VAR<=N; VAR++)
@@ -76,7 +76,7 @@ typedef enum {
  * Debug flags
  * Not yet widely applied
  */
-enum DebugFlags {
+enum DebugFlags : unsigned char {
   DEBUG_NONE          = 0,
   DEBUG_ECHO          = _BV(0), ///< Echo commands in order as they are processed
   DEBUG_INFO          = _BV(1), ///< Print messages for code that has debug output
@@ -88,7 +88,7 @@ enum DebugFlags {
   DEBUG_ALL           = 0xFF
 };
 
-enum EndstopEnum {
+enum EndstopEnum : char {
   X_MIN,
   Y_MIN,
   Z_MIN,
@@ -105,7 +105,7 @@ enum EndstopEnum {
 };
 
 #if ENABLED(EMERGENCY_PARSER)
-  enum e_parser_state {
+  enum e_parser_state : char {
     state_RESET,
     state_N,
     state_M,
@@ -122,14 +122,14 @@ enum EndstopEnum {
 #endif
 
 #if ENABLED(ADVANCED_PAUSE_FEATURE)
-  enum AdvancedPauseMenuResponse {
+  enum AdvancedPauseMenuResponse : char {
     ADVANCED_PAUSE_RESPONSE_WAIT_FOR,
     ADVANCED_PAUSE_RESPONSE_EXTRUDE_MORE,
     ADVANCED_PAUSE_RESPONSE_RESUME_PRINT
   };
 
   #if ENABLED(ULTIPANEL)
-    enum AdvancedPauseMessage {
+    enum AdvancedPauseMessage : char {
       ADVANCED_PAUSE_MESSAGE_INIT,
       ADVANCED_PAUSE_MESSAGE_UNLOAD,
       ADVANCED_PAUSE_MESSAGE_INSERT,
@@ -143,7 +143,7 @@ enum EndstopEnum {
     };
   #endif
 
-  enum AdvancedPauseMode {
+  enum AdvancedPauseMode : char {
     ADVANCED_PAUSE_MODE_PAUSE_PRINT,
     ADVANCED_PAUSE_MODE_LOAD_FILAMENT,
     ADVANCED_PAUSE_MODE_UNLOAD_FILAMENT
@@ -155,7 +155,7 @@ enum EndstopEnum {
  * Marlin sends messages if blocked or busy
  */
 #if ENABLED(HOST_KEEPALIVE_FEATURE)
-  enum MarlinBusyState {
+  enum MarlinBusyState : char {
     NOT_BUSY,           // Not in a handler
     IN_HANDLER,         // Processing a GCode
     IN_PROCESS,         // Known to be blocking command input (as in G29)
@@ -167,12 +167,12 @@ enum EndstopEnum {
 /**
  * SD Card
  */
-enum LsAction { LS_SerialPrint, LS_Count, LS_GetFilename };
+enum LsAction : char { LS_SerialPrint, LS_Count, LS_GetFilename };
 
 /**
  * Ultra LCD
  */
-enum LCDViewAction {
+enum LCDViewAction : char {
   LCDVIEW_NONE,
   LCDVIEW_REDRAW_NOW,
   LCDVIEW_CALL_REDRAW_NEXT,
@@ -184,7 +184,7 @@ enum LCDViewAction {
  * Dual X Carriage modes. A Dual Nozzle can also do duplication.
  */
 #if ENABLED(DUAL_X_CARRIAGE) || ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
-  enum DualXMode {
+  enum DualXMode : char {
     DXC_FULL_CONTROL_MODE,  // DUAL_X_CARRIAGE only
     DXC_AUTO_PARK_MODE,     // DUAL_X_CARRIAGE only
     DXC_DUPLICATION_MODE
@@ -196,7 +196,7 @@ enum LCDViewAction {
  * (and "canned cycles" - not a current feature)
  */
 #if ENABLED(CNC_WORKSPACE_PLANES)
-  enum WorkspacePlane { PLANE_XY, PLANE_ZX, PLANE_YZ };
+  enum WorkspacePlane : char { PLANE_XY, PLANE_ZX, PLANE_YZ };
 #endif
 
 #endif // __ENUM_H__