Massdrop keyboard updates for SEND_STRING, syscalls, stdio, debug prints, Auto Shift (#3973)

* Update for SEND_STRING usage

Update for SEND_STRING usage.
Sending keyboard reports (kbd, nkro) now obey the minimum polling time.
While attempting to send a keyboard report and waiting for a USB poll, other functions of the keyboard, including LED effects and power management, will continue to operate at their intended intervals.

* Updates for send string, syscalls, stdio, debug prints, auto shift

Now properly waiting for previous keys sent over USB to complete before sending new.
Added heap to linker and now compiling with syscalls support.
Removed custom string functions and now using stdio.
dprintf now works as intended through virtser device.

* CTRL and ALT keymap updates

CTRL mac keymap updated
ALT default and mac keymap updated
ALT rules.mk added Auto Shift with default no

* Code cleanup as per discussion with vomindoraan

Code cleanup as per discussion with vomindoraan

2 files changed, 15 insertions, 53 deletions

diff --git a/keyboards/massdrop/alt/keymaps/default/keymap.c b/keyboards/massdrop/alt/keymaps/default/keymap.c
index 0cbce86293..a5c443ffcd 100644
--- a/keyboards/massdrop/alt/keymaps/default/keymap.c
+++ b/keyboards/massdrop/alt/keymaps/default/keymap.c
@@ -136,8 +136,7 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
         case L_T_BR:
             if (record->event.pressed) {
                 led_animation_breathing = !led_animation_breathing;
-                if (led_animation_breathing)
-                {
+                if (led_animation_breathing) {
                     gcr_breathe = gcr_desired;
                     led_animation_breathe_cur = BREATHE_MIN_STEP;
                     breathe_dir = 1;
@@ -151,50 +150,32 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
             return false;
         case U_T_AUTO:
             if (record->event.pressed && MODS_SHIFT && MODS_CTRL) {
-                usb_extra_manual = !usb_extra_manual;
-                CDC_print("USB extra port manual mode ");
-                CDC_print(usb_extra_manual ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(usb_extra_manual, "USB extra port manual mode");
             }
             return false;
         case U_T_AGCR:
             if (record->event.pressed && MODS_SHIFT && MODS_CTRL) {
-                usb_gcr_auto = !usb_gcr_auto;
-                CDC_print("USB GCR auto mode ");
-                CDC_print(usb_gcr_auto ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(usb_gcr_auto, "USB GCR auto mode");
             }
             return false;
         case DBG_TOG:
             if (record->event.pressed) {
-                debug_enable = !debug_enable;
-                CDC_print("Debug mode ");
-                CDC_print(debug_enable ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(debug_enable, "Debug mode");
             }
             return false;
         case DBG_MTRX:
             if (record->event.pressed) {
-                debug_matrix = !debug_matrix;
-                CDC_print("Debug matrix ");
-                CDC_print(debug_matrix ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(debug_matrix, "Debug matrix");
             }
             return false;
         case DBG_KBD:
             if (record->event.pressed) {
-                debug_keyboard = !debug_keyboard;
-                CDC_print("Debug keyboard ");
-                CDC_print(debug_keyboard ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(debug_keyboard, "Debug keyboard");
             }
             return false;
         case DBG_MOU:
             if (record->event.pressed) {
-                debug_mouse = !debug_mouse;
-                CDC_print("Debug mouse ");
-                CDC_print(debug_mouse ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(debug_mouse, "Debug mouse");
             }
             return false;
         case MD_BOOT:
@@ -209,4 +190,4 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
         default:
             return true; //Process all other keycodes normally
     }
-}
\ No newline at end of file
+}
diff --git a/keyboards/massdrop/alt/keymaps/mac/keymap.c b/keyboards/massdrop/alt/keymaps/mac/keymap.c
index e886290e7e..d6978fd801 100644
--- a/keyboards/massdrop/alt/keymaps/mac/keymap.c
+++ b/keyboards/massdrop/alt/keymaps/mac/keymap.c
@@ -136,8 +136,7 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
         case L_T_BR:
             if (record->event.pressed) {
                 led_animation_breathing = !led_animation_breathing;
-                if (led_animation_breathing)
-                {
+                if (led_animation_breathing) {
                     gcr_breathe = gcr_desired;
                     led_animation_breathe_cur = BREATHE_MIN_STEP;
                     breathe_dir = 1;
@@ -151,50 +150,32 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
             return false;
         case U_T_AUTO:
             if (record->event.pressed && MODS_SHIFT && MODS_CTRL) {
-                usb_extra_manual = !usb_extra_manual;
-                CDC_print("USB extra port manual mode ");
-                CDC_print(usb_extra_manual ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(usb_extra_manual, "USB extra port manual mode");
             }
             return false;
         case U_T_AGCR:
             if (record->event.pressed && MODS_SHIFT && MODS_CTRL) {
-                usb_gcr_auto = !usb_gcr_auto;
-                CDC_print("USB GCR auto mode ");
-                CDC_print(usb_gcr_auto ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(usb_gcr_auto, "USB GCR auto mode");
             }
             return false;
         case DBG_TOG:
             if (record->event.pressed) {
-                debug_enable = !debug_enable;
-                CDC_print("Debug mode ");
-                CDC_print(debug_enable ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(debug_enable, "Debug mode");
             }
             return false;
         case DBG_MTRX:
             if (record->event.pressed) {
-                debug_matrix = !debug_matrix;
-                CDC_print("Debug matrix ");
-                CDC_print(debug_matrix ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(debug_matrix, "Debug matrix");
             }
             return false;
         case DBG_KBD:
             if (record->event.pressed) {
-                debug_keyboard = !debug_keyboard;
-                CDC_print("Debug keyboard ");
-                CDC_print(debug_keyboard ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(debug_keyboard, "Debug keyboard");
             }
             return false;
         case DBG_MOU:
             if (record->event.pressed) {
-                debug_mouse = !debug_mouse;
-                CDC_print("Debug mouse ");
-                CDC_print(debug_mouse ? "enabled" : "disabled");
-                CDC_print("\r\n");
+                TOGGLE_FLAG_AND_PRINT(debug_mouse, "Debug mouse");
             }
             return false;
         case MD_BOOT: