improve cmake warning flags, fix various warnings in examples

27 files changed, 174 insertions, 80 deletions

diff --git a/examples/build_system/cmake/toolchain/common.cmake b/examples/build_system/cmake/toolchain/common.cmake
index 4c181137b..fa3034e6f 100644
--- a/examples/build_system/cmake/toolchain/common.cmake
+++ b/examples/build_system/cmake/toolchain/common.cmake
@@ -20,11 +20,11 @@ include(${CMAKE_CURRENT_LIST_DIR}/../cpu/${CMAKE_SYSTEM_CPU}.cmake)
 # ----------------------------------------------------------------------------
 # Compile flags
 # ----------------------------------------------------------------------------
-if (TOOLCHAIN STREQUAL "gcc")
+if (TOOLCHAIN STREQUAL "gcc" OR TOOLCHAIN STREQUAL "clang")
   list(APPEND TOOLCHAIN_COMMON_FLAGS
     -fdata-sections
     -ffunction-sections
-    -fsingle-precision-constant
+#    -fsingle-precision-constant # not supported by clang
     -fno-strict-aliasing
     )
   list(APPEND TOOLCHAIN_EXE_LINKER_FLAGS
@@ -34,22 +34,9 @@ if (TOOLCHAIN STREQUAL "gcc")
     )
 
 elseif (TOOLCHAIN STREQUAL "iar")
-  #list(APPEND TOOLCHAIN_COMMON_FLAGS)
   list(APPEND TOOLCHAIN_EXE_LINKER_FLAGS
     --diag_suppress=Li065
     )
-
-elseif (TOOLCHAIN STREQUAL "clang")
-  list(APPEND TOOLCHAIN_COMMON_FLAGS
-    -fdata-sections
-    -ffunction-sections
-    -fno-strict-aliasing
-    )
-  list(APPEND TOOLCHAIN_EXE_LINKER_FLAGS
-    -Wl,--print-memory-usage
-    -Wl,--gc-sections
-    -Wl,--cref
-    )
 endif ()
 
 # join the toolchain flags into a single string
diff --git a/examples/device/cdc_uac2/src/common.h b/examples/device/cdc_uac2/src/common.h
index f281024c7..ff8b7a953 100644
--- a/examples/device/cdc_uac2/src/common.h
+++ b/examples/device/cdc_uac2/src/common.h
@@ -31,4 +31,7 @@ enum
   VOLUME_CTRL_SILENCE = 0x8000,
 };
 
+void led_blinking_task(void);
+void audio_task(void);
+
 #endif
diff --git a/examples/device/cdc_uac2/src/main.c b/examples/device/cdc_uac2/src/main.c
index bc87f6e3c..22c462be7 100644
--- a/examples/device/cdc_uac2/src/main.c
+++ b/examples/device/cdc_uac2/src/main.c
@@ -38,9 +38,6 @@ extern uint32_t blink_interval_ms;
 #include "pico/stdlib.h"
 #endif
 
-void led_blinking_task(void);
-void audio_task(void);
-
 /*------------- MAIN -------------*/
 int main(void)
 {
diff --git a/examples/device/net_lwip_webserver/src/main.c b/examples/device/net_lwip_webserver/src/main.c
index dd9f213ae..867cf2812 100644
--- a/examples/device/net_lwip_webserver/src/main.c
+++ b/examples/device/net_lwip_webserver/src/main.c
@@ -58,6 +58,7 @@ try changing the first byte of tud_network_mac_address[] below from 0x02 to 0x00
 #include "lwip/ethip6.h"
 #include "lwip/init.h"
 #include "lwip/timeouts.h"
+#include "lwip/sys.h"
 
 #ifdef INCLUDE_IPERF
   #include "lwip/apps/lwiperf.h"
@@ -172,7 +173,7 @@ static void init_lwip(void) {
 }
 
 /* handle any DNS requests from dns-server */
-bool dns_query_proc(const char *name, ip4_addr_t *addr) {
+static bool dns_query_proc(const char *name, ip4_addr_t *addr) {
   if (0 == strcmp(name, "tiny.usb")) {
     *addr = ipaddr;
     return true;
diff --git a/examples/device/usbtmc/src/main.c b/examples/device/usbtmc/src/main.c
index f78cce91f..5cbbb85ef 100644
--- a/examples/device/usbtmc/src/main.c
+++ b/examples/device/usbtmc/src/main.c
@@ -29,6 +29,7 @@
 
 #include "bsp/board_api.h"
 #include "tusb.h"
+#include "main.h"
 #include "usbtmc_app.h"
 //--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF PROTYPES
diff --git a/examples/device/usbtmc/src/usbtmc_app.c b/examples/device/usbtmc/src/usbtmc_app.c
index e738f1008..4c3724ac4 100644
--- a/examples/device/usbtmc/src/usbtmc_app.c
+++ b/examples/device/usbtmc/src/usbtmc_app.c
@@ -28,6 +28,7 @@
 #include "tusb.h"
 #include "bsp/board_api.h"
 #include "main.h"
+#include "usbtmc_app.h"
 
 #if (CFG_TUD_USBTMC_ENABLE_488)
 static usbtmc_response_capabilities_488_t const
diff --git a/examples/device/video_capture_2ch/src/main.c b/examples/device/video_capture_2ch/src/main.c
index f56738f67..a63efa82d 100644
--- a/examples/device/video_capture_2ch/src/main.c
+++ b/examples/device/video_capture_2ch/src/main.c
@@ -180,7 +180,7 @@ static void fill_color_bar(uint8_t* buffer, unsigned start_position) {
 }
 #endif
 
-size_t get_framebuf(uint_fast8_t ctl_idx, uint_fast8_t stm_idx, size_t fnum, void **fb) {
+static size_t get_framebuf(uint_fast8_t ctl_idx, uint_fast8_t stm_idx, size_t fnum, void **fb) {
   uint32_t idx = ctl_idx + stm_idx;
 
   if (idx == 0) {
@@ -205,8 +205,7 @@ size_t get_framebuf(uint_fast8_t ctl_idx, uint_fast8_t stm_idx, size_t fnum, voi
 //--------------------------------------------------------------------+
 //
 //--------------------------------------------------------------------+
-
-void video_send_frame(uint_fast8_t ctl_idx, uint_fast8_t stm_idx) {
+static void video_send_frame(uint_fast8_t ctl_idx, uint_fast8_t stm_idx) {
   static unsigned start_ms[CFG_TUD_VIDEO_STREAMING] = {0, };
   static unsigned already_sent = 0;
 
diff --git a/examples/device/webusb_serial/src/main.c b/examples/device/webusb_serial/src/main.c
index 4a724f45e..0c2acd94e 100644
--- a/examples/device/webusb_serial/src/main.c
+++ b/examples/device/webusb_serial/src/main.c
@@ -107,7 +107,7 @@ int main(void) {
 }
 
 // send characters to both CDC and WebUSB
-void echo_all(const uint8_t buf[], uint32_t count) {
+static void echo_all(const uint8_t buf[], uint32_t count) {
   // echo to web serial
   if (web_serial_connected) {
     tud_vendor_write(buf, count);
diff --git a/examples/host/cdc_msc_hid/src/app.h b/examples/host/cdc_msc_hid/src/app.h
new file mode 100644
index 000000000..bf15c7bea
--- /dev/null
+++ b/examples/host/cdc_msc_hid/src/app.h
@@ -0,0 +1,32 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+#ifndef TUSB_TINYUSB_EXAMPLES_APP_H
+#define TUSB_TINYUSB_EXAMPLES_APP_H
+
+void cdc_app_task(void);
+void hid_app_task(void);
+
+#endif
diff --git a/examples/host/cdc_msc_hid/src/cdc_app.c b/examples/host/cdc_msc_hid/src/cdc_app.c
index 97f1a96d6..d3daedffc 100644
--- a/examples/host/cdc_msc_hid/src/cdc_app.c
+++ b/examples/host/cdc_msc_hid/src/cdc_app.c
@@ -26,6 +26,7 @@
 
 #include "tusb.h"
 #include "bsp/board_api.h"
+#include "app.h"
 
 static size_t get_console_inputs(uint8_t* buf, size_t bufsize) {
   size_t count = 0;
diff --git a/examples/host/cdc_msc_hid/src/hid_app.c b/examples/host/cdc_msc_hid/src/hid_app.c
index 6f01d6f45..f6a83aeed 100644
--- a/examples/host/cdc_msc_hid/src/hid_app.c
+++ b/examples/host/cdc_msc_hid/src/hid_app.c
@@ -25,6 +25,7 @@
 
 #include "bsp/board_api.h"
 #include "tusb.h"
+#include "app.h"
 
 //--------------------------------------------------------------------+
 // MACRO TYPEDEF CONSTANT ENUM DECLARATION
diff --git a/examples/host/cdc_msc_hid/src/main.c b/examples/host/cdc_msc_hid/src/main.c
index e2dd6e5d2..c309a7cae 100644
--- a/examples/host/cdc_msc_hid/src/main.c
+++ b/examples/host/cdc_msc_hid/src/main.c
@@ -29,13 +29,12 @@
 
 #include "bsp/board_api.h"
 #include "tusb.h"
+#include "app.h"
 
 //--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF PROTOTYPES
 //--------------------------------------------------------------------+
 void led_blinking_task(void);
-extern void cdc_app_task(void);
-extern void hid_app_task(void);
 
 /*------------- MAIN -------------*/
 int main(void) {
diff --git a/examples/host/cdc_msc_hid_freertos/src/app.h b/examples/host/cdc_msc_hid_freertos/src/app.h
new file mode 100644
index 000000000..960f7e8cc
--- /dev/null
+++ b/examples/host/cdc_msc_hid_freertos/src/app.h
@@ -0,0 +1,33 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+#ifndef TUSB_TINYUSB_EXAMPLES_APP_H
+#define TUSB_TINYUSB_EXAMPLES_APP_H
+
+void cdc_app_init(void);
+void hid_app_init(void);
+void msc_app_init(void);
+
+#endif
diff --git a/examples/host/cdc_msc_hid_freertos/src/cdc_app.c b/examples/host/cdc_msc_hid_freertos/src/cdc_app.c
index d99760a02..279efe7b7 100644
--- a/examples/host/cdc_msc_hid_freertos/src/cdc_app.c
+++ b/examples/host/cdc_msc_hid_freertos/src/cdc_app.c
@@ -26,6 +26,7 @@
 
 #include "tusb.h"
 #include "bsp/board_api.h"
+#include "app.h"
 
 #ifdef ESP_PLATFORM
   #define CDC_STACK_SZIE      2048
diff --git a/examples/host/cdc_msc_hid_freertos/src/hid_app.c b/examples/host/cdc_msc_hid_freertos/src/hid_app.c
index 9ea5c1be0..0b4ee2c78 100644
--- a/examples/host/cdc_msc_hid_freertos/src/hid_app.c
+++ b/examples/host/cdc_msc_hid_freertos/src/hid_app.c
@@ -25,6 +25,7 @@
 
 #include "bsp/board_api.h"
 #include "tusb.h"
+#include "app.h"
 
 //--------------------------------------------------------------------+
 // MACRO TYPEDEF CONSTANT ENUM DECLARATION
@@ -160,7 +161,7 @@ static void process_kbd_report(hid_keyboard_report_t const *report) {
 // Mouse
 //--------------------------------------------------------------------+
 
-void cursor_movement(int8_t x, int8_t y, int8_t wheel) {
+static void cursor_movement(int8_t x, int8_t y, int8_t wheel) {
 #if USE_ANSI_ESCAPE
   // Move X using ansi escape
   if ( x < 0) {
diff --git a/examples/host/cdc_msc_hid_freertos/src/main.c b/examples/host/cdc_msc_hid_freertos/src/main.c
index d498c1b57..5dab2bed0 100644
--- a/examples/host/cdc_msc_hid_freertos/src/main.c
+++ b/examples/host/cdc_msc_hid_freertos/src/main.c
@@ -29,6 +29,7 @@
 
 #include "bsp/board_api.h"
 #include "tusb.h"
+#include "app.h"
 
 #ifdef ESP_PLATFORM
   #define USBH_STACK_SIZE     4096
@@ -65,9 +66,6 @@ TimerHandle_t blinky_tm;
 static void led_blinky_cb(TimerHandle_t xTimer);
 static void usb_host_task(void* param);
 
-extern void cdc_app_init(void);
-extern void hid_app_init(void);
-extern void msc_app_init(void);
 
 /*------------- MAIN -------------*/
 int main(void) {
diff --git a/examples/host/cdc_msc_hid_freertos/src/msc_app.c b/examples/host/cdc_msc_hid_freertos/src/msc_app.c
index 6439495a8..a6e3ed4ee 100644
--- a/examples/host/cdc_msc_hid_freertos/src/msc_app.c
+++ b/examples/host/cdc_msc_hid_freertos/src/msc_app.c
@@ -24,6 +24,7 @@
  */
 
 #include "tusb.h"
+#include "app.h"
 
 // define the buffer to be place in USB/DMA memory with correct alignment/cache line size
 CFG_TUH_MEM_SECTION static struct {
diff --git a/examples/host/hid_controller/src/app.h b/examples/host/hid_controller/src/app.h
new file mode 100644
index 000000000..1f9015cd2
--- /dev/null
+++ b/examples/host/hid_controller/src/app.h
@@ -0,0 +1,31 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+#ifndef TUSB_TINYUSB_EXAMPLES_APP_H
+#define TUSB_TINYUSB_EXAMPLES_APP_H
+
+void hid_app_task(void);
+
+#endif
diff --git a/examples/host/hid_controller/src/hid_app.c b/examples/host/hid_controller/src/hid_app.c
index 1d6ca8b07..f8c3d029b 100644
--- a/examples/host/hid_controller/src/hid_app.c
+++ b/examples/host/hid_controller/src/hid_app.c
@@ -25,6 +25,7 @@
 
 #include "bsp/board_api.h"
 #include "tusb.h"
+#include "app.h"
 
 /* From https://www.kernel.org/doc/html/latest/input/gamepad.html
           ____________________________              __
diff --git a/examples/host/hid_controller/src/main.c b/examples/host/hid_controller/src/main.c
index f3244db95..fa70d7d1a 100644
--- a/examples/host/hid_controller/src/main.c
+++ b/examples/host/hid_controller/src/main.c
@@ -34,18 +34,15 @@
 
 #include "bsp/board_api.h"
 #include "tusb.h"
+#include "app.h"
 
 //--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF PROTYPES
 //--------------------------------------------------------------------+
 void led_blinking_task(void);
 
-extern void cdc_task(void);
-extern void hid_app_task(void);
-
 /*------------- MAIN -------------*/
-int main(void)
-{
+int main(void) {
   board_init();
 
   printf("TinyUSB Host HID Controller Example\r\n");
@@ -60,19 +57,11 @@ int main(void)
 
   board_init_after_tusb();
 
-  while (1)
-  {
+  while (1) {
     // tinyusb host task
     tuh_task();
     led_blinking_task();
-
-#if CFG_TUH_CDC
-    cdc_task();
-#endif
-
-#if CFG_TUH_HID
     hid_app_task();
-#endif
   }
 }
 
@@ -83,8 +72,7 @@ int main(void)
 //--------------------------------------------------------------------+
 // Blinking Task
 //--------------------------------------------------------------------+
-void led_blinking_task(void)
-{
+void led_blinking_task(void) {
   const uint32_t interval_ms = 1000;
   static uint32_t start_ms = 0;
 
diff --git a/hw/bsp/board.c b/hw/bsp/board.c
index e141664da..a51978479 100644
--- a/hw/bsp/board.c
+++ b/hw/bsp/board.c
@@ -180,9 +180,11 @@ uint32_t tusb_time_millis_api(void) {
 // FreeRTOS hooks
 //--------------------------------------------------------------------
 #if CFG_TUSB_OS == OPT_OS_FREERTOS && !defined(ESP_PLATFORM)
+
 #include "FreeRTOS.h"
 #include "task.h"
 
+void vApplicationMallocFailedHook(void); // missing prototype
 void vApplicationMallocFailedHook(void) {
   taskDISABLE_INTERRUPTS();
   TU_ASSERT(false, );
@@ -199,7 +201,7 @@ void vApplicationStackOverflowHook(xTaskHandle pxTask, char *pcTaskName) {
 /* configSUPPORT_STATIC_ALLOCATION is set to 1, so the application must provide an
  * implementation of vApplicationGetIdleTaskMemory() to provide the memory that is
  * used by the Idle task. */
-void vApplicationGetIdleTaskMemory( StaticTask_t **ppxIdleTaskTCBBuffer, StackType_t **ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize ) {
+void vApplicationGetIdleTaskMemory(StaticTask_t **ppxIdleTaskTCBBuffer, StackType_t **ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize) {
   /* If the buffers to be provided to the Idle task are declared inside this
    * function then they must be declared static - otherwise they will be allocated on
    * the stack and so not exists after this function exits. */
@@ -243,6 +245,8 @@ void vApplicationGetTimerTaskMemory( StaticTask_t **ppxTimerTaskTCBBuffer, Stack
 }
 
 #if CFG_TUSB_MCU == OPT_MCU_RX63X || CFG_TUSB_MCU == OPT_MCU_RX65X
+void vApplicationSetupTimerInterrupt(void);
+
 #include "iodefine.h"
 void vApplicationSetupTimerInterrupt(void) {
   /* Enable CMT0 */
diff --git a/hw/bsp/family_support.cmake b/hw/bsp/family_support.cmake
index 9ec80df91..daabed81b 100644
--- a/hw/bsp/family_support.cmake
+++ b/hw/bsp/family_support.cmake
@@ -38,6 +38,35 @@ if (NOT DEFINED TOOLCHAIN)
   set(TOOLCHAIN gcc)
 endif ()
 
+set(WARN_FLAGS_GNU
+  -Wall
+  -Wextra
+  -Werror
+  -Wfatal-errors
+  -Wdouble-promotion
+  -Wstrict-prototypes
+  -Wstrict-overflow
+  -Werror-implicit-function-declaration
+  -Wfloat-equal
+  -Wundef
+  -Wshadow
+  -Wwrite-strings
+  -Wsign-compare
+  -Wmissing-format-attribute
+  -Wunreachable-code
+  -Wcast-align
+  -Wcast-function-type
+  -Wcast-qual
+  -Wnull-dereference
+  -Wuninitialized
+  -Wunused
+  -Wunused-function
+  -Wreturn-type
+  -Wredundant-decls
+  -Wmissing-prototypes
+  )
+set(WARN_FLAGS_Clang ${WARN_FLAGS_GNU})
+
 # Optimization
 if (NOT DEFINED CMAKE_BUILD_TYPE OR CMAKE_BUILD_TYPE STREQUAL "")
   set(CMAKE_BUILD_TYPE MinSizeRel CACHE STRING "Build type" FORCE)
@@ -48,8 +77,8 @@ endif ()
 #-------------------------------------------------------------
 if (NOT DEFINED FAMILY)
   if (NOT DEFINED BOARD)
-    message(FATAL_ERROR "You must set a FAMILY variable for the build (e.g. rp2040, espressif).
-    You can do this via -DFAMILY=xxx on the cmake command line")
+    message(FATAL_ERROR "You must set a BOARD variable for the build (e.g. metro_m4_express, raspberry_pi_pico).
+    You can do this via -DBOARD=xxx on the cmake command line")
   endif ()
 
   # Find path contains BOARD
@@ -226,33 +255,7 @@ function(family_configure_common TARGET RTOS)
   endif ()
 
   if (CMAKE_C_COMPILER_ID STREQUAL "GNU" OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
-    target_compile_options(${TARGET} PRIVATE
-      -Wall
-      -Wextra
-      #-Werror
-      -Wfatal-errors
-      -Wdouble-promotion
-      -Wstrict-prototypes
-      -Wstrict-overflow
-      -Werror-implicit-function-declaration
-      -Wfloat-equal
-      -Wundef
-      -Wshadow
-      -Wwrite-strings
-      -Wsign-compare
-      -Wmissing-format-attribute
-      -Wunreachable-code
-      -Wcast-align
-      -Wcast-function-type
-      -Wcast-qual
-      -Wnull-dereference
-      -Wuninitialized
-      -Wunused
-      -Wunused-function
-      -Wreturn-type
-      -Wredundant-decls
-      -Wmissing-prototypes
-      )
+    target_compile_options(${TARGET} PRIVATE ${WARN_FLAGS_${CMAKE_C_COMPILER_ID}})
     target_link_options(${TARGET} PUBLIC "LINKER:-Map=$<TARGET_FILE:${TARGET}>.map")
     if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 12.0
       AND NO_WARN_RWX_SEGMENTS_SUPPORTED AND (NOT RTOS STREQUAL zephyr))
diff --git a/lib/networking/dhserver.c b/lib/networking/dhserver.c
index 9dedf87e2..87a63c5de 100644
--- a/lib/networking/dhserver.c
+++ b/lib/networking/dhserver.c
@@ -145,7 +145,7 @@ static __inline void free_entry(dhcp_entry_t *entry)
 	memset(entry->mac, 0, 6);
 }
 
-uint8_t *find_dhcp_option(uint8_t *attrs, int size, uint8_t attr)
+static uint8_t *find_dhcp_option(uint8_t *attrs, int size, uint8_t attr)
 {
 	int i = 0;
 	while ((i + 1) < size)
@@ -159,7 +159,7 @@ uint8_t *find_dhcp_option(uint8_t *attrs, int size, uint8_t attr)
 	return NULL;
 }
 
-int fill_options(void *dest,
+static int fill_options(void *dest,
 	uint8_t msg_type,
 	const char *domain,
 	ip4_addr_t dns,
diff --git a/lib/networking/rndis_reports.c b/lib/networking/rndis_reports.c
index 451d5405b..e2849fb10 100644
--- a/lib/networking/rndis_reports.c
+++ b/lib/networking/rndis_reports.c
@@ -29,7 +29,10 @@
 
 #include <stdalign.h>
 #include <string.h>
-#include "class/net/net_device.h"
+#include "tusb.h"
+
+#if CFG_TUD_ECM_RNDIS
+
 #include "rndis_protocol.h"
 #include "netif/ethernet.h"
 
@@ -299,3 +302,5 @@ void rndis_class_set_handler(uint8_t *data, int size)
       break;
   }
 }
+
+#endif
diff --git a/src/class/audio/audio_device.h b/src/class/audio/audio_device.h
index fd47c649d..00948767e 100644
--- a/src/class/audio/audio_device.h
+++ b/src/class/audio/audio_device.h
@@ -360,6 +360,7 @@ bool tud_audio_feedback_format_correction_cb(uint8_t func_id);
 
 #if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
 void tud_audio_int_done_cb(uint8_t rhport);
+void tud_audio_int_xfer_cb(uint8_t rhport);
 #endif
 
 // Invoked when audio set interface request received
diff --git a/src/class/net/ecm_rndis_device.c b/src/class/net/ecm_rndis_device.c
index 299eb97c8..7dff66823 100644
--- a/src/class/net/ecm_rndis_device.c
+++ b/src/class/net/ecm_rndis_device.c
@@ -35,8 +35,6 @@
 #include "net_device.h"
 #include "rndis_protocol.h"
 
-extern void rndis_class_set_handler(uint8_t *data, int size); /* found in ./misc/networking/rndis_reports.c */
-
 #define CFG_TUD_NET_PACKET_PREFIX_LEN sizeof(rndis_data_packet_t)
 #define CFG_TUD_NET_PACKET_SUFFIX_LEN 0
 
diff --git a/src/class/net/net_device.h b/src/class/net/net_device.h
index fff2623b7..ef5ecffc8 100644
--- a/src/class/net/net_device.h
+++ b/src/class/net/net_device.h
@@ -56,6 +56,13 @@ typedef enum
 #endif
 
 //--------------------------------------------------------------------+
+// Implemented by Application
+//--------------------------------------------------------------------+
+#if CFG_TUD_ECM_RNDIS
+extern void rndis_class_set_handler(uint8_t *data, int size);
+#endif
+
+//--------------------------------------------------------------------+
 // Application API
 //--------------------------------------------------------------------+