Make T G-code optional, as well as the T parameter

Marlin/src/MarlinCore.cpp

@@ -219,7 +219,9 @@
   #include "feature/fanmux.h"
 #endif
 
-#include "module/tool_change.h"
+#if HAS_TOOLCHANGE
+  #include "module/tool_change.h"
+#endif
 
 #if HAS_FANCHECK
   #include "feature/fancheck.h"

Marlin/src/gcode/bedlevel/G26.cpp

@@ -501,8 +501,10 @@ void GcodeSuite::G26() {
   // or if the parameter parsing did not go OK, abort
   if (homing_needed_error()) return;
 
-  // Change the tool first, if specified
-  if (parser.seenval('T')) tool_change(parser.value_int());
+  #if HAS_TOOLCHANGE
+    // Change the tool first, if specified
+    if (parser.seenval('T')) tool_change(parser.value_int());
+  #endif
 
   g26_helper_t g26;
 

Marlin/src/gcode/config/M217.cpp

@@ -25,7 +25,10 @@
 #if HAS_MULTI_EXTRUDER
 
 #include "../gcode.h"
-#include "../../module/tool_change.h"
+
+#if HAS_TOOLCHANGE
+  #include "../../module/tool_change.h"
+#endif
 
 #if ENABLED(TOOLCHANGE_MIGRATION_FEATURE)
   #include "../../module/motion.h" // for active_extruder
@@ -119,7 +122,7 @@ void GcodeSuite::M217() {
     #endif
   #endif
 
-  #if HAS_Z_AXIS
+  #if HAS_Z_AXIS && HAS_TOOLCHANGE
     if (parser.seenval('Z')) { toolchange_settings.z_raise = parser.value_linear_units(); }
   #endif
 

Marlin/src/gcode/control/T.cpp

@@ -20,6 +20,10 @@
  *
  */
 
+#include "../../inc/MarlinConfigPre.h"
+
+#if HAS_TOOLCHANGE
+
 #include "../gcode.h"
 #include "../../module/tool_change.h"
 
@@ -76,3 +80,5 @@ void GcodeSuite::T(const int8_t tool_index) {
     #endif
   );
 }
+
+#endif // HAS_TOOLCHANGE

Marlin/src/gcode/gcode.cpp

@@ -122,14 +122,16 @@ void GcodeSuite::say_units() {
  * Return -1 if the T parameter is out of range
  */
 int8_t GcodeSuite::get_target_extruder_from_command() {
-  if (parser.seenval('T')) {
-    const int8_t e = parser.value_byte();
-    if (e < EXTRUDERS) return e;
-    SERIAL_ECHO_START();
-    SERIAL_CHAR('M'); SERIAL_ECHO(parser.codenum);
-    SERIAL_ECHOLNPGM(" " STR_INVALID_EXTRUDER " ", e);
-    return -1;
-  }
+  #if HAS_TOOLCHANGE
+    if (parser.seenval('T')) {
+      const int8_t e = parser.value_byte();
+      if (e < EXTRUDERS) return e;
+      SERIAL_ECHO_START();
+      SERIAL_CHAR('M'); SERIAL_ECHO(parser.codenum);
+      SERIAL_ECHOLNPGM(" " STR_INVALID_EXTRUDER " ", e);
+      return -1;
+    }
+  #endif
   return active_extruder;
 }
 

Marlin/src/gcode/gcode.h

@@ -1285,7 +1285,7 @@ class GcodeSuite {
     static void M710_report(const bool forReplay=true);
   #endif
 
-  static void T(const int8_t tool_index);
+  static void T(const int8_t tool_index) IF_DISABLED(HAS_TOOLCHANGE, { UNUSED(tool_index); });
 
 };
 

Marlin/src/inc/Conditionals_adv.h

@@ -803,6 +803,10 @@
   #endif
 #endif
 
+#if HAS_MULTI_EXTRUDER || HAS_MULTI_HOTEND || HAS_PRUSA_MMU2 || (ENABLED(MIXING_EXTRUDER) && MIXING_VIRTUAL_TOOLS > 1)
+  #define HAS_TOOLCHANGE 1
+#endif
+
 #if ENABLED(MIXING_EXTRUDER) && (ENABLED(RETRACT_SYNC_MIXING) || ALL(FILAMENT_LOAD_UNLOAD_GCODES, FILAMENT_UNLOAD_ALL_EXTRUDERS))
   #define HAS_MIXER_SYNC_CHANNEL 1
 #endif

Marlin/src/module/tool_change.cpp

@@ -22,6 +22,8 @@
 
 #include "../inc/MarlinConfigPre.h"
 
+#if HAS_TOOLCHANGE
+
 #include "tool_change.h"
 
 #include "motion.h"
@@ -1629,3 +1631,5 @@ void tool_change(const uint8_t new_tool, bool no_move/*=false*/) {
   }
 
 #endif // TOOLCHANGE_MIGRATION_FEATURE
+
+#endif // HAS_TOOLCHANGE

ini/features.ini

@@ -306,6 +306,7 @@ SERVO_DETACH_GCODE                     = build_src_filter=+<src/gcode/control/M2
 HAS_DUPLICATION_MODE                   = build_src_filter=+<src/gcode/control/M605.cpp>
 SPI_FLASH_BACKUP                       = build_src_filter=+<src/gcode/control/M993_M994.cpp>
 PLATFORM_M997_SUPPORT                  = build_src_filter=+<src/gcode/control/M997.cpp>
+HAS_TOOLCHANGE                         = build_src_filter=+<src/gcode/control/T.cpp>
 FT_MOTION                              = build_src_filter=+<src/module/ft_motion.cpp> +<src/gcode/feature/ft_motion>
 LIN_ADVANCE                            = build_src_filter=+<src/gcode/feature/advance>
 PHOTO_GCODE                            = build_src_filter=+<src/gcode/feature/camera>

platformio.ini

@@ -107,7 +107,6 @@ default_src_filter = +<src/*> -<src/config> -<src/tests>
   +<src/gcode/control/M111.cpp>
   +<src/gcode/control/M120_M121.cpp>
   +<src/gcode/control/M999.cpp>
-  +<src/gcode/control/T.cpp>
   +<src/gcode/geometry/G92.cpp>
   +<src/gcode/host/M110.cpp>
   +<src/gcode/host/M114.cpp>