8 files changed, 53 insertions, 0 deletions
diff --git a/keyboards/helix/config.h b/keyboards/helix/config.h
index 7bd4d26456..fbfbd32804 100644
--- a/keyboards/helix/config.h
+++ b/keyboards/helix/config.h
@@ -39,4 +39,13 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //     ./tmk_core
 //     ......
 
+#ifdef USE_Link_Time_Optimization
+  // LTO has issues with macros (action_get_macro) and "functions" (fn_actions),
+  //  so just disable them
+  #define NO_ACTION_MACRO
+  #define NO_ACTION_FUNCTION
+
+  #define DISABLE_LEADER
+#endif // USE_Link_Time_Optimization
+
 #endif /* CONFIG_H */
diff --git a/keyboards/helix/pico/keymaps/default/rules.mk b/keyboards/helix/pico/keymaps/default/rules.mk
index 18b1d596b4..afb1240685 100644
--- a/keyboards/helix/pico/keymaps/default/rules.mk
+++ b/keyboards/helix/pico/keymaps/default/rules.mk
@@ -35,6 +35,7 @@ LED_BACK_ENABLE = no        # LED backlight (Enable WS2812 RGB underlight.)
 LED_UNDERGLOW_ENABLE = no   # LED underglow (Enable WS2812 RGB underlight.)
 LED_ANIMATIONS = yes        # LED animations
 IOS_DEVICE_ENABLE = no      # connect to IOS device (iPad,iPhone)
+Link_Time_Optimization = no # if firmware size over limit, try this option
 
 ####  LED_BACK_ENABLE and LED_UNDERGLOW_ENABLE.
 ####    Do not enable these with audio at the same time.
@@ -102,6 +103,19 @@ ifeq ($(strip $(LOCAL_GLCDFONT)), yes)
     OPT_DEFS += -DLOCAL_GLCDFONT
 endif
 
+ifeq ($(strip $(AUDIO_ENABLE)),yes)
+  ifeq ($(strip $(RGBLIGHT_ENABLE)),yes)
+    Link_Time_Optimization = yes
+  endif
+  ifeq ($(strip $(OLED_ENABLE)),yes)
+    Link_Time_Optimization = yes
+  endif
+endif
+
+ifeq ($(strip $(Link_Time_Optimization)),yes)
+    EXTRAFLAGS += -flto -DUSE_Link_Time_Optimization
+endif
+
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
diff --git a/keyboards/helix/rev2/keymaps/default/rules.mk b/keyboards/helix/rev2/keymaps/default/rules.mk
index 4174a30457..5340a74ba2 100644
--- a/keyboards/helix/rev2/keymaps/default/rules.mk
+++ b/keyboards/helix/rev2/keymaps/default/rules.mk
@@ -36,6 +36,7 @@ LED_BACK_ENABLE = no        # LED backlight (Enable WS2812 RGB underlight.)
 LED_UNDERGLOW_ENABLE = no   # LED underglow (Enable WS2812 RGB underlight.)
 LED_ANIMATIONS = yes        # LED animations
 IOS_DEVICE_ENABLE = no      # connect to IOS device (iPad,iPhone)
+Link_Time_Optimization = no # if firmware size over limit, try this option
 
 ####  LED_BACK_ENABLE and LED_UNDERGLOW_ENABLE.
 ####    Do not enable these with audio at the same time.
@@ -110,6 +111,10 @@ ifeq ($(strip $(LOCAL_GLCDFONT)), yes)
     OPT_DEFS += -DLOCAL_GLCDFONT
 endif
 
+ifeq ($(strip $(Link_Time_Optimization)),yes)
+    EXTRAFLAGS += -flto -DUSE_Link_Time_Optimization
+endif
+
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
diff --git a/keyboards/helix/rev2/keymaps/edvorakjp/rules.mk b/keyboards/helix/rev2/keymaps/edvorakjp/rules.mk
index d8fc35c486..67da9c370b 100644
--- a/keyboards/helix/rev2/keymaps/edvorakjp/rules.mk
+++ b/keyboards/helix/rev2/keymaps/edvorakjp/rules.mk
@@ -35,6 +35,7 @@ LED_BACK_ENABLE = no        # LED backlight (Enable WS2812 RGB underlight.)
 LED_UNDERGLOW_ENABLE = no   # LED underglow (Enable WS2812 RGB underlight.)
 LED_ANIMATIONS = yes        # LED animations
 IOS_DEVICE_ENABLE = no      # connect to IOS device (iPad,iPhone)
+Link_Time_Optimization = no # if firmware size over limit, try this option
 
 ####  LED_BACK_ENABLE and LED_UNDERGLOW_ENABLE.
 ####    Do not enable these with audio at the same time.
@@ -113,6 +114,10 @@ ifeq ($(strip $(LOCAL_GLCDFONT)), yes)
   OPT_DEFS += -DLOCAL_GLCDFONT
 endif
 
+ifeq ($(strip $(Link_Time_Optimization)),yes)
+    EXTRAFLAGS += -flto -DUSE_Link_Time_Optimization
+endif
+
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
diff --git a/keyboards/helix/rev2/keymaps/five_rows/rules.mk b/keyboards/helix/rev2/keymaps/five_rows/rules.mk
index 53a00d8d4d..402f855ae1 100644
--- a/keyboards/helix/rev2/keymaps/five_rows/rules.mk
+++ b/keyboards/helix/rev2/keymaps/five_rows/rules.mk
@@ -36,6 +36,7 @@ LED_BACK_ENABLE = no        # LED backlight (Enable WS2812 RGB underlight.)
 LED_UNDERGLOW_ENABLE = no   # LED underglow (Enable WS2812 RGB underlight.)
 LED_ANIMATIONS = yes        # LED animations
 IOS_DEVICE_ENABLE = no      # connect to IOS device (iPad,iPhone)
+Link_Time_Optimization = no # if firmware size over limit, try this option
 
 ####  LED_BACK_ENABLE and LED_UNDERGLOW_ENABLE.
 ####    Do not enable these with audio at the same time.
@@ -110,6 +111,10 @@ ifeq ($(strip $(LOCAL_GLCDFONT)), yes)
     OPT_DEFS += -DLOCAL_GLCDFONT
 endif
 
+ifeq ($(strip $(Link_Time_Optimization)),yes)
+    EXTRAFLAGS += -flto -DUSE_Link_Time_Optimization
+endif
+
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
diff --git a/keyboards/helix/rev2/keymaps/five_rows_jis/rules.mk b/keyboards/helix/rev2/keymaps/five_rows_jis/rules.mk
index 4174a30457..5340a74ba2 100644
--- a/keyboards/helix/rev2/keymaps/five_rows_jis/rules.mk
+++ b/keyboards/helix/rev2/keymaps/five_rows_jis/rules.mk
@@ -36,6 +36,7 @@ LED_BACK_ENABLE = no        # LED backlight (Enable WS2812 RGB underlight.)
 LED_UNDERGLOW_ENABLE = no   # LED underglow (Enable WS2812 RGB underlight.)
 LED_ANIMATIONS = yes        # LED animations
 IOS_DEVICE_ENABLE = no      # connect to IOS device (iPad,iPhone)
+Link_Time_Optimization = no # if firmware size over limit, try this option
 
 ####  LED_BACK_ENABLE and LED_UNDERGLOW_ENABLE.
 ####    Do not enable these with audio at the same time.
@@ -110,6 +111,10 @@ ifeq ($(strip $(LOCAL_GLCDFONT)), yes)
     OPT_DEFS += -DLOCAL_GLCDFONT
 endif
 
+ifeq ($(strip $(Link_Time_Optimization)),yes)
+    EXTRAFLAGS += -flto -DUSE_Link_Time_Optimization
+endif
+
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
diff --git a/keyboards/helix/rev2/keymaps/froggy/rules.mk b/keyboards/helix/rev2/keymaps/froggy/rules.mk
index 2052b8f4e3..aa97964134 100644
--- a/keyboards/helix/rev2/keymaps/froggy/rules.mk
+++ b/keyboards/helix/rev2/keymaps/froggy/rules.mk
@@ -36,6 +36,7 @@ LED_BACK_ENABLE = yes        # LED backlight (Enable WS2812 RGB underlight.)
 LED_UNDERGLOW_ENABLE = no   # LED underglow (Enable WS2812 RGB underlight.)
 LED_ANIMATIONS = yes        # LED animations
 IOS_DEVICE_ENABLE = no      # connect to IOS device (iPad,iPhone)
+Link_Time_Optimization = no # if firmware size over limit, try this option
 
 ####  LED_BACK_ENABLE and LED_UNDERGLOW_ENABLE.
 ####    Do not enable these with audio at the same time.
@@ -110,6 +111,10 @@ ifeq ($(strip $(LOCAL_GLCDFONT)), yes)
     OPT_DEFS += -DLOCAL_GLCDFONT
 endif
 
+ifeq ($(strip $(Link_Time_Optimization)),yes)
+    EXTRAFLAGS += -flto -DUSE_Link_Time_Optimization
+endif
+
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
diff --git a/keyboards/helix/rev2/keymaps/led_test/rules.mk b/keyboards/helix/rev2/keymaps/led_test/rules.mk
index b3cd5ee42a..c7ee75c36b 100644
--- a/keyboards/helix/rev2/keymaps/led_test/rules.mk
+++ b/keyboards/helix/rev2/keymaps/led_test/rules.mk
@@ -36,6 +36,7 @@ LED_BACK_ENABLE = yes        # LED backlight (Enable WS2812 RGB underlight.)
 LED_UNDERGLOW_ENABLE = no   # LED underglow (Enable WS2812 RGB underlight.)
 LED_ANIMATIONS = yes        # LED animations
 IOS_DEVICE_ENABLE = no      # connect to IOS device (iPad,iPhone)
+Link_Time_Optimization = no # if firmware size over limit, try this option
 
 ####  LED_BACK_ENABLE and LED_UNDERGLOW_ENABLE.
 ####    Do not enable these with audio at the same time.
@@ -110,6 +111,10 @@ ifeq ($(strip $(LOCAL_GLCDFONT)), yes)
     OPT_DEFS += -DLOCAL_GLCDFONT
 endif
 
+ifeq ($(strip $(Link_Time_Optimization)),yes)
+    EXTRAFLAGS += -flto -DUSE_Link_Time_Optimization
+endif
+
 SRC += led_test_init.c
 
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE