Add `compiler_support.h` (#25274)

22 files changed, 92 insertions, 50 deletions

diff --git a/quantum/audio/audio.h b/quantum/audio/audio.h
index 93dc6f62b1..647744a686 100644
--- a/quantum/audio/audio.h
+++ b/quantum/audio/audio.h
@@ -18,6 +18,8 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+
+#include "compiler_support.h"
 #include "musical_notes.h"
 #include "song_list.h"
 #include "voices.h"
@@ -38,7 +40,7 @@ typedef union audio_config_t {
     };
 } audio_config_t;
 
-_Static_assert(sizeof(audio_config_t) == sizeof(uint8_t), "Audio EECONFIG out of spec.");
+STATIC_ASSERT(sizeof(audio_config_t) == sizeof(uint8_t), "Audio EECONFIG out of spec.");
 
 /*
  * a 'musical note' is represented by pitch and duration; a 'musical tone' adds intensity and timbre
diff --git a/quantum/backlight/backlight.h b/quantum/backlight/backlight.h
index 561c7f8a94..2faa8fc4f2 100644
--- a/quantum/backlight/backlight.h
+++ b/quantum/backlight/backlight.h
@@ -20,6 +20,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <stdint.h>
 #include <stdbool.h>
 
+#include "compiler_support.h"
+
 #ifndef BACKLIGHT_LEVELS
 #    define BACKLIGHT_LEVELS 3
 #elif BACKLIGHT_LEVELS > 31
@@ -44,7 +46,7 @@ typedef union backlight_config_t {
     };
 } backlight_config_t;
 
-_Static_assert(sizeof(backlight_config_t) == sizeof(uint8_t), "Backlight EECONFIG out of spec.");
+STATIC_ASSERT(sizeof(backlight_config_t) == sizeof(uint8_t), "Backlight EECONFIG out of spec.");
 
 void    backlight_init(void);
 void    backlight_toggle(void);
diff --git a/quantum/compiler_support.h b/quantum/compiler_support.h
new file mode 100644
index 0000000000..5c0c4d2835
--- /dev/null
+++ b/quantum/compiler_support.h
@@ -0,0 +1,15 @@
+// Copyright 2025 QMK Contributors
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/**
+ * @brief Perfom an assertion at compile time.
+ *
+ * `_Static_assert` is C<23, while `static_assert` is C++/C23.
+ */
+#if !defined(STATIC_ASSERT)
+#    ifdef __cplusplus
+#        define STATIC_ASSERT static_assert
+#    else
+#        define STATIC_ASSERT _Static_assert
+#    endif
+#endif
diff --git a/quantum/connection/connection.h b/quantum/connection/connection.h
index e403141fae..b25160c759 100644
--- a/quantum/connection/connection.h
+++ b/quantum/connection/connection.h
@@ -3,6 +3,8 @@
 #pragma once
 
 #include <stdint.h>
+
+#include "compiler_support.h"
 #include "util.h"
 
 /**
@@ -29,7 +31,7 @@ typedef union connection_config_t {
     connection_host_t desired_host : 8;
 } PACKED connection_config_t;
 
-_Static_assert(sizeof(connection_config_t) == sizeof(uint8_t), "Connection EECONFIG out of spec.");
+STATIC_ASSERT(sizeof(connection_config_t) == sizeof(uint8_t), "Connection EECONFIG out of spec.");
 
 /**
  * \brief Initialize the subsystem.
diff --git a/quantum/haptic.h b/quantum/haptic.h
index e27f546d40..f854c75ec3 100644
--- a/quantum/haptic.h
+++ b/quantum/haptic.h
@@ -20,6 +20,8 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+#include "compiler_support.h"
+
 #ifndef HAPTIC_DEFAULT_FEEDBACK
 #    define HAPTIC_DEFAULT_FEEDBACK 0
 #endif
@@ -42,7 +44,7 @@ typedef union haptic_config_t {
     };
 } haptic_config_t;
 
-_Static_assert(sizeof(haptic_config_t) == sizeof(uint32_t), "Haptic EECONFIG out of spec.");
+STATIC_ASSERT(sizeof(haptic_config_t) == sizeof(uint32_t), "Haptic EECONFIG out of spec.");
 
 typedef enum HAPTIC_FEEDBACK {
     KEY_PRESS,
diff --git a/quantum/keycode_config.h b/quantum/keycode_config.h
index 529cd0e127..804f1381d0 100644
--- a/quantum/keycode_config.h
+++ b/quantum/keycode_config.h
@@ -16,9 +16,7 @@
 
 #pragma once
 
-#ifdef __cplusplus
-#    define _Static_assert static_assert
-#endif
+#include "compiler_support.h"
 
 #include "eeconfig.h"
 #include "keycode.h"
@@ -47,6 +45,6 @@ typedef union keymap_config_t {
     };
 } keymap_config_t;
 
-_Static_assert(sizeof(keymap_config_t) == sizeof(uint16_t), "Keycode (magic) EECONFIG out of spec.");
+STATIC_ASSERT(sizeof(keymap_config_t) == sizeof(uint16_t), "Keycode (magic) EECONFIG out of spec.");
 
 extern keymap_config_t keymap_config;
diff --git a/quantum/keymap_introspection.c b/quantum/keymap_introspection.c
index 23e842353a..99fd3f929e 100644
--- a/quantum/keymap_introspection.c
+++ b/quantum/keymap_introspection.c
@@ -13,6 +13,7 @@
 #    include INTROSPECTION_KEYMAP_C
 #endif // INTROSPECTION_KEYMAP_C
 
+#include "compiler_support.h"
 #include "keymap_introspection.h"
 #include "util.h"
 
@@ -30,9 +31,9 @@ __attribute__((weak)) uint8_t keymap_layer_count(void) {
 }
 
 #ifdef DYNAMIC_KEYMAP_ENABLE
-_Static_assert(NUM_KEYMAP_LAYERS_RAW <= MAX_LAYER, "Number of keymap layers exceeds maximum set by DYNAMIC_KEYMAP_LAYER_COUNT");
+STATIC_ASSERT(NUM_KEYMAP_LAYERS_RAW <= MAX_LAYER, "Number of keymap layers exceeds maximum set by DYNAMIC_KEYMAP_LAYER_COUNT");
 #else
-_Static_assert(NUM_KEYMAP_LAYERS_RAW <= MAX_LAYER, "Number of keymap layers exceeds maximum set by LAYER_STATE_(8|16|32)BIT");
+STATIC_ASSERT(NUM_KEYMAP_LAYERS_RAW <= MAX_LAYER, "Number of keymap layers exceeds maximum set by LAYER_STATE_(8|16|32)BIT");
 #endif
 
 uint16_t keycode_at_keymap_location_raw(uint8_t layer_num, uint8_t row, uint8_t column) {
@@ -61,7 +62,7 @@ __attribute__((weak)) uint8_t encodermap_layer_count(void) {
     return encodermap_layer_count_raw();
 }
 
-_Static_assert(NUM_KEYMAP_LAYERS_RAW == NUM_ENCODERMAP_LAYERS_RAW, "Number of encoder_map layers doesn't match the number of keymap layers");
+STATIC_ASSERT(NUM_KEYMAP_LAYERS_RAW == NUM_ENCODERMAP_LAYERS_RAW, "Number of encoder_map layers doesn't match the number of keymap layers");
 
 uint16_t keycode_at_encodermap_location_raw(uint8_t layer_num, uint8_t encoder_idx, bool clockwise) {
     if (layer_num < NUM_ENCODERMAP_LAYERS_RAW && encoder_idx < NUM_ENCODERS) {
@@ -106,7 +107,7 @@ __attribute__((weak)) uint16_t combo_count(void) {
     return combo_count_raw();
 }
 
-_Static_assert(ARRAY_SIZE(key_combos) <= (QK_KB), "Number of combos is abnormally high. Are you using SAFE_RANGE in an enum for combos?");
+STATIC_ASSERT(ARRAY_SIZE(key_combos) <= (QK_KB), "Number of combos is abnormally high. Are you using SAFE_RANGE in an enum for combos?");
 
 combo_t* combo_get_raw(uint16_t combo_idx) {
     if (combo_idx >= combo_count_raw()) {
@@ -133,7 +134,7 @@ __attribute__((weak)) uint16_t tap_dance_count(void) {
     return tap_dance_count_raw();
 }
 
-_Static_assert(ARRAY_SIZE(tap_dance_actions) <= (QK_TAP_DANCE_MAX - QK_TAP_DANCE), "Number of tap dance actions exceeds maximum. Are you using SAFE_RANGE in tap dance enum?");
+STATIC_ASSERT(ARRAY_SIZE(tap_dance_actions) <= (QK_TAP_DANCE_MAX - QK_TAP_DANCE), "Number of tap dance actions exceeds maximum. Are you using SAFE_RANGE in tap dance enum?");
 
 tap_dance_action_t* tap_dance_get_raw(uint16_t tap_dance_idx) {
     if (tap_dance_idx >= tap_dance_count_raw()) {
@@ -161,7 +162,7 @@ __attribute__((weak)) uint16_t key_override_count(void) {
     return key_override_count_raw();
 }
 
-_Static_assert(ARRAY_SIZE(key_overrides) <= (QK_KB), "Number of key overrides is abnormally high. Are you using SAFE_RANGE in an enum for key overrides?");
+STATIC_ASSERT(ARRAY_SIZE(key_overrides) <= (QK_KB), "Number of key overrides is abnormally high. Are you using SAFE_RANGE in an enum for key overrides?");
 
 const key_override_t* key_override_get_raw(uint16_t key_override_idx) {
     if (key_override_idx >= key_override_count_raw()) {
diff --git a/quantum/led_matrix/led_matrix_types.h b/quantum/led_matrix/led_matrix_types.h
index 810420f46f..26a199701e 100644
--- a/quantum/led_matrix/led_matrix_types.h
+++ b/quantum/led_matrix/led_matrix_types.h
@@ -18,6 +18,8 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+
+#include "compiler_support.h"
 #include "util.h"
 
 #if defined(LED_MATRIX_KEYPRESSES) || defined(LED_MATRIX_KEYRELEASES)
@@ -82,4 +84,4 @@ typedef union led_eeconfig_t {
     };
 } led_eeconfig_t;
 
-_Static_assert(sizeof(led_eeconfig_t) == sizeof(uint32_t), "LED Matrix EECONFIG out of spec.");
+STATIC_ASSERT(sizeof(led_eeconfig_t) == sizeof(uint32_t), "LED Matrix EECONFIG out of spec.");
diff --git a/quantum/nvm/eeprom/nvm_dynamic_keymap.c b/quantum/nvm/eeprom/nvm_dynamic_keymap.c
index 5f514acc1a..3e315f2bcb 100644
--- a/quantum/nvm/eeprom/nvm_dynamic_keymap.c
+++ b/quantum/nvm/eeprom/nvm_dynamic_keymap.c
@@ -1,6 +1,7 @@
 // Copyright 2024 Nick Brassel (@tzarc)
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include "compiler_support.h"
 #include "keycodes.h"
 #include "eeprom.h"
 #include "dynamic_keymap.h"
@@ -25,10 +26,10 @@
 #    define DYNAMIC_KEYMAP_EEPROM_MAX_ADDR (TOTAL_EEPROM_BYTE_COUNT - 1)
 #endif
 
-_Static_assert(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR <= (TOTAL_EEPROM_BYTE_COUNT - 1), "DYNAMIC_KEYMAP_EEPROM_MAX_ADDR is configured to use more space than what is available for the selected EEPROM driver");
+STATIC_ASSERT(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR <= (TOTAL_EEPROM_BYTE_COUNT - 1), "DYNAMIC_KEYMAP_EEPROM_MAX_ADDR is configured to use more space than what is available for the selected EEPROM driver");
 
 // Due to usage of uint16_t check for max 65535
-_Static_assert(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR <= 65535, "DYNAMIC_KEYMAP_EEPROM_MAX_ADDR must be less than 65536");
+STATIC_ASSERT(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR <= 65535, "DYNAMIC_KEYMAP_EEPROM_MAX_ADDR must be less than 65536");
 
 // If DYNAMIC_KEYMAP_EEPROM_ADDR not explicitly defined in config.h,
 #ifndef DYNAMIC_KEYMAP_EEPROM_ADDR
@@ -56,7 +57,7 @@ _Static_assert(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR <= 65535, "DYNAMIC_KEYMAP_EEPROM_M
 // The keyboard should override DYNAMIC_KEYMAP_LAYER_COUNT to reduce it,
 // or DYNAMIC_KEYMAP_EEPROM_MAX_ADDR to increase it, *only if* the microcontroller has
 // more than the default.
-_Static_assert((DYNAMIC_KEYMAP_EEPROM_MAX_ADDR) - (DYNAMIC_KEYMAP_MACRO_EEPROM_ADDR) >= 100, "Dynamic keymaps are configured to use more EEPROM than is available.");
+STATIC_ASSERT((DYNAMIC_KEYMAP_EEPROM_MAX_ADDR) - (DYNAMIC_KEYMAP_MACRO_EEPROM_ADDR) >= 100, "Dynamic keymaps are configured to use more EEPROM than is available.");
 
 #ifndef TOTAL_EEPROM_BYTE_COUNT
 #    error Unknown total EEPROM size. Cannot derive maximum for dynamic keymaps.
diff --git a/quantum/nvm/eeprom/nvm_eeprom_eeconfig_internal.h b/quantum/nvm/eeprom/nvm_eeprom_eeconfig_internal.h
index 41b76f1f65..78b8190eaf 100644
--- a/quantum/nvm/eeprom/nvm_eeprom_eeconfig_internal.h
+++ b/quantum/nvm/eeprom/nvm_eeprom_eeconfig_internal.h
@@ -4,6 +4,8 @@
 
 #include <stdint.h>
 #include <stddef.h> // offsetof
+
+#include "compiler_support.h"
 #include "eeconfig.h"
 #include "util.h"
 
@@ -58,4 +60,4 @@ typedef struct PACKED {
 // Size of EEPROM being used, other code can refer to this for available EEPROM
 #define EECONFIG_SIZE ((EECONFIG_BASE_SIZE) + (EECONFIG_KB_DATA_SIZE) + (EECONFIG_USER_DATA_SIZE))
 
-_Static_assert((intptr_t)EECONFIG_HANDEDNESS == 14, "EEPROM handedness offset is incorrect");
+STATIC_ASSERT((intptr_t)EECONFIG_HANDEDNESS == 14, "EEPROM handedness offset is incorrect");
diff --git a/quantum/painter/qff.h b/quantum/painter/qff.h
index c3b831da17..ed88508d73 100644
--- a/quantum/painter/qff.h
+++ b/quantum/painter/qff.h
@@ -9,6 +9,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+#include "compiler_support.h"
 #include "qp_stream.h"
 #include "qp_internal.h"
 #include "qgf.h"
@@ -36,7 +37,7 @@ typedef struct QP_PACKED qff_font_descriptor_v1_t {
     uint8_t               transparency_index;  // palette index used for transparent pixels (not yet implemented)
 } qff_font_descriptor_v1_t;
 
-_Static_assert(sizeof(qff_font_descriptor_v1_t) == (sizeof(qgf_block_header_v1_t) + 20), "qff_font_descriptor_v1_t must be 25 bytes in v1 of QFF");
+STATIC_ASSERT(sizeof(qff_font_descriptor_v1_t) == (sizeof(qgf_block_header_v1_t) + 20), "qff_font_descriptor_v1_t must be 25 bytes in v1 of QFF");
 
 #define QFF_MAGIC 0x464651
 
@@ -54,14 +55,14 @@ typedef struct QP_PACKED qff_ascii_glyph_v1_t {
     uint32_t value : 24; // Uses QFF_GLYPH_*_(BITS|MASK) as bitfield ordering is compiler-defined
 } qff_ascii_glyph_v1_t;
 
-_Static_assert(sizeof(qff_ascii_glyph_v1_t) == 3, "qff_ascii_glyph_v1_t must be 3 bytes in v1 of QFF");
+STATIC_ASSERT(sizeof(qff_ascii_glyph_v1_t) == 3, "qff_ascii_glyph_v1_t must be 3 bytes in v1 of QFF");
 
 typedef struct QP_PACKED qff_ascii_glyph_table_v1_t {
     qgf_block_header_v1_t header;    // = { .type_id = 0x01, .neg_type_id = (~0x01), .length = 285 }
     qff_ascii_glyph_v1_t  glyph[95]; // 95 glyphs, 0x20..0x7E
 } qff_ascii_glyph_table_v1_t;
 
-_Static_assert(sizeof(qff_ascii_glyph_table_v1_t) == (sizeof(qgf_block_header_v1_t) + (95 * sizeof(qff_ascii_glyph_v1_t))), "qff_ascii_glyph_table_v1_t must be 290 bytes in v1 of QFF");
+STATIC_ASSERT(sizeof(qff_ascii_glyph_table_v1_t) == (sizeof(qgf_block_header_v1_t) + (95 * sizeof(qff_ascii_glyph_v1_t))), "qff_ascii_glyph_table_v1_t must be 290 bytes in v1 of QFF");
 
 /////////////////////////////////////////
 // Unicode glyph table descriptor
@@ -73,7 +74,7 @@ typedef struct QP_PACKED qff_unicode_glyph_v1_t {
     uint32_t value : 24; // Uses QFF_GLYPH_*_(BITS|MASK) as bitfield ordering is compiler-defined
 } qff_unicode_glyph_v1_t;
 
-_Static_assert(sizeof(qff_unicode_glyph_v1_t) == 6, "qff_unicode_glyph_v1_t must be 6 bytes in v1 of QFF");
+STATIC_ASSERT(sizeof(qff_unicode_glyph_v1_t) == 6, "qff_unicode_glyph_v1_t must be 6 bytes in v1 of QFF");
 
 typedef struct QP_PACKED qff_unicode_glyph_table_v1_t {
     qgf_block_header_v1_t  header;   // = { .type_id = 0x02, .neg_type_id = (~0x02), .length = (N * 6) }
diff --git a/quantum/painter/qgf.h b/quantum/painter/qgf.h
index 33a37709e6..a1e245f15d 100644
--- a/quantum/painter/qgf.h
+++ b/quantum/painter/qgf.h
@@ -9,6 +9,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+#include "compiler_support.h"
 #include "qp_stream.h"
 #include "qp_internal.h"
 
@@ -24,7 +25,7 @@ typedef struct QP_PACKED qgf_block_header_v1_t {
     uint32_t length : 24; // 24-bit blob length, allowing for block sizes of a maximum of 16MB.
 } qgf_block_header_v1_t;
 
-_Static_assert(sizeof(qgf_block_header_v1_t) == 5, "qgf_block_header_v1_t must be 5 bytes in v1 of QGF");
+STATIC_ASSERT(sizeof(qgf_block_header_v1_t) == 5, "qgf_block_header_v1_t must be 5 bytes in v1 of QGF");
 
 /////////////////////////////////////////
 // Graphics descriptor
@@ -42,7 +43,7 @@ typedef struct QP_PACKED qgf_graphics_descriptor_v1_t {
     uint16_t              frame_count;         // minimum of 1
 } qgf_graphics_descriptor_v1_t;
 
-_Static_assert(sizeof(qgf_graphics_descriptor_v1_t) == (sizeof(qgf_block_header_v1_t) + 18), "qgf_graphics_descriptor_v1_t must be 23 bytes in v1 of QGF");
+STATIC_ASSERT(sizeof(qgf_graphics_descriptor_v1_t) == (sizeof(qgf_block_header_v1_t) + 18), "qgf_graphics_descriptor_v1_t must be 23 bytes in v1 of QGF");
 
 #define QGF_MAGIC 0x464751
 
@@ -56,7 +57,7 @@ typedef struct QP_PACKED qgf_frame_offsets_v1_t {
     uint32_t              offset[0]; // '0' signifies that this struct is immediately followed by the frame offsets
 } qgf_frame_offsets_v1_t;
 
-_Static_assert(sizeof(qgf_frame_offsets_v1_t) == sizeof(qgf_block_header_v1_t), "qgf_frame_offsets_v1_t must only contain qgf_block_header_v1_t in v1 of QGF");
+STATIC_ASSERT(sizeof(qgf_frame_offsets_v1_t) == sizeof(qgf_block_header_v1_t), "qgf_frame_offsets_v1_t must only contain qgf_block_header_v1_t in v1 of QGF");
 
 /////////////////////////////////////////
 // Frame descriptor
@@ -72,7 +73,7 @@ typedef struct QP_PACKED qgf_frame_v1_t {
     uint16_t              delay;                  // frame delay time for animations (in units of milliseconds)
 } qgf_frame_v1_t;
 
-_Static_assert(sizeof(qgf_frame_v1_t) == (sizeof(qgf_block_header_v1_t) + 6), "qgf_frame_v1_t must be 11 bytes in v1 of QGF");
+STATIC_ASSERT(sizeof(qgf_frame_v1_t) == (sizeof(qgf_block_header_v1_t) + 6), "qgf_frame_v1_t must be 11 bytes in v1 of QGF");
 
 #define QGF_FRAME_FLAG_DELTA 0x02
 #define QGF_FRAME_FLAG_TRANSPARENT 0x01
@@ -88,14 +89,14 @@ typedef struct QP_PACKED qgf_palette_entry_v1_t {
     uint8_t v; // value component: `[0,1]` is mapped to `[0,255]` uint8_t.
 } qgf_palette_entry_v1_t;
 
-_Static_assert(sizeof(qgf_palette_entry_v1_t) == 3, "Palette entry is not 3 bytes in size");
+STATIC_ASSERT(sizeof(qgf_palette_entry_v1_t) == 3, "Palette entry is not 3 bytes in size");
 
 typedef struct QP_PACKED qgf_palette_v1_t {
     qgf_block_header_v1_t  header; // = { .type_id = 0x03, .neg_type_id = (~0x03), .length = (N * 3 * sizeof(uint8_t)) }
     qgf_palette_entry_v1_t hsv[0]; // N * hsv, where N is the number of palette entries depending on the frame format in the descriptor
 } qgf_palette_v1_t;
 
-_Static_assert(sizeof(qgf_palette_v1_t) == sizeof(qgf_block_header_v1_t), "qgf_palette_v1_t must only contain qgf_block_header_v1_t in v1 of QGF");
+STATIC_ASSERT(sizeof(qgf_palette_v1_t) == sizeof(qgf_block_header_v1_t), "qgf_palette_v1_t must only contain qgf_block_header_v1_t in v1 of QGF");
 
 /////////////////////////////////////////
 // Frame delta descriptor
@@ -110,7 +111,7 @@ typedef struct QP_PACKED qgf_delta_v1_t {
     uint16_t              bottom; // The bottom pixel location to to draw the delta image
 } qgf_delta_v1_t;
 
-_Static_assert(sizeof(qgf_delta_v1_t) == (sizeof(qgf_block_header_v1_t) + 8), "qgf_delta_v1_t must be 13 bytes in v1 of QGF");
+STATIC_ASSERT(sizeof(qgf_delta_v1_t) == (sizeof(qgf_block_header_v1_t) + 8), "qgf_delta_v1_t must be 13 bytes in v1 of QGF");
 
 /////////////////////////////////////////
 // Frame data descriptor
@@ -122,7 +123,7 @@ typedef struct QP_PACKED qgf_data_v1_t {
     uint8_t               data[0]; // 0 signifies that this struct is immediately followed by the length of data specified in the header
 } qgf_data_v1_t;
 
-_Static_assert(sizeof(qgf_data_v1_t) == sizeof(qgf_block_header_v1_t), "qgf_data_v1_t must only contain qgf_block_header_v1_t in v1 of QGF");
+STATIC_ASSERT(sizeof(qgf_data_v1_t) == sizeof(qgf_block_header_v1_t), "qgf_data_v1_t must only contain qgf_block_header_v1_t in v1 of QGF");
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // QGF API
diff --git a/quantum/painter/qp_draw_core.c b/quantum/painter/qp_draw_core.c
index aa5fa4aa76..852abb19e8 100644
--- a/quantum/painter/qp_draw_core.c
+++ b/quantum/painter/qp_draw_core.c
@@ -2,12 +2,13 @@
 // Copyright 2021 Paul Cotter (@gr1mr3aver)
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include "compiler_support.h"
 #include "qp_internal.h"
 #include "qp_comms.h"
 #include "qp_draw.h"
 #include "qgf.h"
 
-_Static_assert((QUANTUM_PAINTER_PIXDATA_BUFFER_SIZE > 0) && (QUANTUM_PAINTER_PIXDATA_BUFFER_SIZE % 16) == 0, "QUANTUM_PAINTER_PIXDATA_BUFFER_SIZE needs to be a non-zero multiple of 16");
+STATIC_ASSERT((QUANTUM_PAINTER_PIXDATA_BUFFER_SIZE > 0) && (QUANTUM_PAINTER_PIXDATA_BUFFER_SIZE % 16) == 0, "QUANTUM_PAINTER_PIXDATA_BUFFER_SIZE needs to be a non-zero multiple of 16");
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Global variables
diff --git a/quantum/painter/qp_internal.c b/quantum/painter/qp_internal.c
index 24b881bd09..fe0c598d78 100644
--- a/quantum/painter/qp_internal.c
+++ b/quantum/painter/qp_internal.c
@@ -3,6 +3,8 @@
 
 #include "qp_internal.h"
 
+#include "compiler_support.h"
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Quantum Painter Core API: device registration
 
@@ -67,7 +69,7 @@ static void qp_internal_display_timeout_task(void) {
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Quantum Painter Core API: qp_internal_task
 
-_Static_assert((QUANTUM_PAINTER_TASK_THROTTLE) > 0 && (QUANTUM_PAINTER_TASK_THROTTLE) < 1000, "QUANTUM_PAINTER_TASK_THROTTLE must be between 1 and 999");
+STATIC_ASSERT((QUANTUM_PAINTER_TASK_THROTTLE) > 0 && (QUANTUM_PAINTER_TASK_THROTTLE) < 1000, "QUANTUM_PAINTER_TASK_THROTTLE must be between 1 and 999");
 
 void qp_internal_task(void) {
     // Perform throttling of the internal processing of Quantum Painter
diff --git a/quantum/painter/qp_internal_formats.h b/quantum/painter/qp_internal_formats.h
index 1beb604b9e..bd7105cab2 100644
--- a/quantum/painter/qp_internal_formats.h
+++ b/quantum/painter/qp_internal_formats.h
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include "compiler_support.h"
 #include "qp_internal.h"
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -29,7 +30,7 @@ typedef union QP_PACKED qp_pixel_t {
 
     uint32_t dummy;
 } qp_pixel_t;
-_Static_assert(sizeof(qp_pixel_t) == 4, "Invalid size for qp_pixel_t");
+STATIC_ASSERT(sizeof(qp_pixel_t) == 4, "Invalid size for qp_pixel_t");
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Quantum Painter image format
diff --git a/quantum/rgb_matrix/rgb_matrix_types.h b/quantum/rgb_matrix/rgb_matrix_types.h
index 62005ebea9..0115edee6a 100644
--- a/quantum/rgb_matrix/rgb_matrix_types.h
+++ b/quantum/rgb_matrix/rgb_matrix_types.h
@@ -18,6 +18,8 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+
+#include "compiler_support.h"
 #include "color.h"
 #include "util.h"
 
@@ -84,4 +86,4 @@ typedef union rgb_config_t {
     };
 } rgb_config_t;
 
-_Static_assert(sizeof(rgb_config_t) == sizeof(uint64_t), "RGB Matrix EECONFIG out of spec.");
+STATIC_ASSERT(sizeof(rgb_config_t) == sizeof(uint64_t), "RGB Matrix EECONFIG out of spec.");
diff --git a/quantum/rgblight/rgblight.h b/quantum/rgblight/rgblight.h
index f5fd450d4c..c061e71895 100644
--- a/quantum/rgblight/rgblight.h
+++ b/quantum/rgblight/rgblight.h
@@ -16,6 +16,8 @@
 
 #pragma once
 
+#include "compiler_support.h"
+
 // DEPRECATED DEFINES - DO NOT USE
 #if defined(RGBLED_NUM)
 #    define RGBLIGHT_LED_COUNT RGBLED_NUM
@@ -260,7 +262,7 @@ typedef union rgblight_config_t {
     };
 } rgblight_config_t;
 
-_Static_assert(sizeof(rgblight_config_t) == sizeof(uint64_t), "RGB Light EECONFIG out of spec.");
+STATIC_ASSERT(sizeof(rgblight_config_t) == sizeof(uint64_t), "RGB Light EECONFIG out of spec.");
 
 typedef struct _rgblight_status_t {
     uint8_t base_mode;
diff --git a/quantum/split_common/split_util.c b/quantum/split_common/split_util.c
index 9af3c29d75..59b6009ec4 100644
--- a/quantum/split_common/split_util.c
+++ b/quantum/split_common/split_util.c
@@ -13,6 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+
+#include "compiler_support.h"
 #include "split_util.h"
 #include "matrix.h"
 #include "keyboard.h"
@@ -62,7 +64,7 @@ static struct {
 } split_config;
 
 #if defined(SPLIT_USB_DETECT)
-_Static_assert((SPLIT_USB_TIMEOUT / SPLIT_USB_TIMEOUT_POLL) <= UINT16_MAX, "Please lower SPLIT_USB_TIMEOUT and/or increase SPLIT_USB_TIMEOUT_POLL.");
+STATIC_ASSERT((SPLIT_USB_TIMEOUT / SPLIT_USB_TIMEOUT_POLL) <= UINT16_MAX, "Please lower SPLIT_USB_TIMEOUT and/or increase SPLIT_USB_TIMEOUT_POLL.");
 static bool usb_bus_detected(void) {
     for (uint16_t i = 0; i < (SPLIT_USB_TIMEOUT / SPLIT_USB_TIMEOUT_POLL); i++) {
         // This will return true if a USB connection has been established
@@ -88,9 +90,9 @@ static inline bool usb_bus_detected(void) {
 #        endif
 #    endif
 #    if defined(SPLIT_USB_DETECT)
-_Static_assert(SPLIT_USB_TIMEOUT < SPLIT_WATCHDOG_TIMEOUT, "SPLIT_WATCHDOG_TIMEOUT should not be below SPLIT_USB_TIMEOUT.");
+STATIC_ASSERT(SPLIT_USB_TIMEOUT < SPLIT_WATCHDOG_TIMEOUT, "SPLIT_WATCHDOG_TIMEOUT should not be below SPLIT_USB_TIMEOUT.");
 #    endif
-_Static_assert(SPLIT_MAX_CONNECTION_ERRORS > 0, "SPLIT_WATCHDOG_ENABLE requires SPLIT_MAX_CONNECTION_ERRORS be above 0 for a functioning disconnection check.");
+STATIC_ASSERT(SPLIT_MAX_CONNECTION_ERRORS > 0, "SPLIT_WATCHDOG_ENABLE requires SPLIT_MAX_CONNECTION_ERRORS be above 0 for a functioning disconnection check.");
 
 static uint32_t split_watchdog_started = 0;
 static bool     split_watchdog_done    = false;
diff --git a/quantum/split_common/transaction_id_define.h b/quantum/split_common/transaction_id_define.h
index 5bfbe2aec7..694737868a 100644
--- a/quantum/split_common/transaction_id_define.h
+++ b/quantum/split_common/transaction_id_define.h
@@ -16,6 +16,8 @@
 
 #pragma once
 
+#include "compiler_support.h"
+
 enum serial_transaction_id {
 #ifdef USE_I2C
     I2C_EXECUTE_CALLBACK,
@@ -122,4 +124,4 @@ enum serial_transaction_id {
 };
 
 // Ensure we only use 5 bits for transaction
-_Static_assert(NUM_TOTAL_TRANSACTIONS <= (1 << 5), "Max number of usable transactions exceeded");
+STATIC_ASSERT(NUM_TOTAL_TRANSACTIONS <= (1 << 5), "Max number of usable transactions exceeded");
diff --git a/quantum/split_common/transport.c b/quantum/split_common/transport.c
index 83edc34859..ea687af1c2 100644
--- a/quantum/split_common/transport.c
+++ b/quantum/split_common/transport.c
@@ -17,6 +17,7 @@
 #include <string.h>
 #include <debug.h>
 
+#include "compiler_support.h"
 #include "transactions.h"
 #include "transport.h"
 #include "transaction_id_define.h"
@@ -36,7 +37,7 @@
 #    include "i2c_slave.h"
 
 // Ensure the I2C buffer has enough space
-_Static_assert(sizeof(split_shared_memory_t) <= I2C_SLAVE_REG_COUNT, "split_shared_memory_t too large for I2C_SLAVE_REG_COUNT");
+STATIC_ASSERT(sizeof(split_shared_memory_t) <= I2C_SLAVE_REG_COUNT, "split_shared_memory_t too large for I2C_SLAVE_REG_COUNT");
 
 split_shared_memory_t *const split_shmem = (split_shared_memory_t *)i2c_slave_reg;
 
diff --git a/quantum/unicode/unicode.h b/quantum/unicode/unicode.h
index f19d803335..7cddc78b7a 100644
--- a/quantum/unicode/unicode.h
+++ b/quantum/unicode/unicode.h
@@ -17,6 +17,8 @@
 #pragma once
 
 #include <stdint.h>
+
+#include "compiler_support.h"
 #include "unicode_keycodes.h"
 
 /**
@@ -33,7 +35,7 @@ typedef union unicode_config_t {
     };
 } unicode_config_t;
 
-_Static_assert(sizeof(unicode_config_t) == sizeof(uint8_t), "Unicode EECONFIG out of spec.");
+STATIC_ASSERT(sizeof(unicode_config_t) == sizeof(uint8_t), "Unicode EECONFIG out of spec.");
 
 extern unicode_config_t unicode_config;
 
diff --git a/quantum/wear_leveling/wear_leveling_internal.h b/quantum/wear_leveling/wear_leveling_internal.h
index e83f9b22ea..c590f42235 100644
--- a/quantum/wear_leveling/wear_leveling_internal.h
+++ b/quantum/wear_leveling/wear_leveling_internal.h
@@ -2,9 +2,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
 
-#ifdef __cplusplus
-#    define _Static_assert static_assert
-#endif
+#include "compiler_support.h"
 
 #include <stdint.h>
 #include <string.h>
@@ -62,9 +60,9 @@ typedef uint64_t backing_store_int_t;
 #endif // WEAR_LEVELING_ASSERTS
 
 // Compile-time validation of configurable options
-_Static_assert(WEAR_LEVELING_BACKING_SIZE >= (WEAR_LEVELING_LOGICAL_SIZE * 2), "Total backing size must be at least twice the size of the logical size");
-_Static_assert(WEAR_LEVELING_LOGICAL_SIZE % BACKING_STORE_WRITE_SIZE == 0, "Logical size must be a multiple of write size");
-_Static_assert(WEAR_LEVELING_BACKING_SIZE % WEAR_LEVELING_LOGICAL_SIZE == 0, "Backing size must be a multiple of logical size");
+STATIC_ASSERT(WEAR_LEVELING_BACKING_SIZE >= (WEAR_LEVELING_LOGICAL_SIZE * 2), "Total backing size must be at least twice the size of the logical size");
+STATIC_ASSERT(WEAR_LEVELING_LOGICAL_SIZE % BACKING_STORE_WRITE_SIZE == 0, "Logical size must be a multiple of write size");
+STATIC_ASSERT(WEAR_LEVELING_BACKING_SIZE % WEAR_LEVELING_LOGICAL_SIZE == 0, "Backing size must be a multiple of logical size");
 
 // Backing Store API, to be implemented elsewhere by flash driver etc.
 bool backing_store_init(void);
@@ -86,7 +84,7 @@ typedef union write_log_entry_t {
     uint8_t  raw8[8];
 } write_log_entry_t;
 
-_Static_assert(sizeof(write_log_entry_t) == 8, "Wear leveling write log entry size was not 8");
+STATIC_ASSERT(sizeof(write_log_entry_t) == 8, "Wear leveling write log entry size was not 8");
 
 /**
  * Log entry type discriminator.
@@ -104,7 +102,7 @@ enum {
     LOG_ENTRY_TYPES
 };
 
-_Static_assert(LOG_ENTRY_TYPES <= (1 << 2), "Too many log entry types to fit into 2 bits of storage");
+STATIC_ASSERT(LOG_ENTRY_TYPES <= (1 << 2), "Too many log entry types to fit into 2 bits of storage");
 
 #define BITMASK_FOR_BITCOUNT(n) ((1 << (n)) - 1)