From 18853defdd2189ee595c6f8c2e4d8a16e41f9ce1 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <thinkyhead@users.noreply.github.com>
Date: Wed, 25 Nov 2020 21:40:56 -0600
Subject: [PATCH] Reduce warnings, extern "C" cleanup (#20279)

---
 Marlin/src/HAL/AVR/HAL.h                      | 16 ++++++++++------
 Marlin/src/HAL/DUE/HAL.h                      | 12 +++++++++---
 Marlin/src/HAL/ESP32/HAL.h                    | 12 +++++++++---
 Marlin/src/HAL/ESP32/timers.h                 |  8 +++++---
 Marlin/src/HAL/HAL.h                          |  4 ++++
 Marlin/src/HAL/LINUX/HAL.cpp                  | 17 ++++++-----------
 Marlin/src/HAL/LINUX/HAL.h                    | 12 +++++++++---
 Marlin/src/HAL/LINUX/include/Arduino.h        | 11 ++++++-----
 Marlin/src/HAL/LPC1768/HAL.cpp                | 17 ++++++-----------
 Marlin/src/HAL/LPC1768/HAL.h                  | 12 +++++++++---
 Marlin/src/HAL/LPC1768/MarlinSerial.cpp       | 19 ++++---------------
 Marlin/src/HAL/LPC1768/main.cpp               | 12 ++++++------
 Marlin/src/HAL/SAMD51/HAL.h                   | 12 +++++++++---
 Marlin/src/HAL/STM32/HAL.h                    | 10 +++++++---
 Marlin/src/HAL/STM32F1/HAL.h                  | 10 +++++++---
 Marlin/src/HAL/STM32F1/timers.h               |  6 ++++--
 Marlin/src/HAL/STM32_F4_F7/HAL.h              | 10 +++++++---
 Marlin/src/HAL/STM32_F4_F7/STM32F4/timers.cpp |  8 +++-----
 Marlin/src/HAL/STM32_F4_F7/STM32F7/timers.cpp |  8 +++-----
 Marlin/src/HAL/TEENSY31_32/HAL.h              | 16 ++++++++++------
 Marlin/src/HAL/TEENSY31_32/timers.h           |  4 ++--
 Marlin/src/HAL/TEENSY35_36/HAL.h              | 16 ++++++++++------
 Marlin/src/HAL/TEENSY35_36/timers.h           |  4 ++--
 Marlin/src/HAL/TEENSY40_41/HAL.h              | 16 ++++++++++------
 Marlin/src/HAL/TEENSY40_41/timers.h           | 10 ++++++----
 Marlin/src/libs/duration_t.h                  | 10 +++++++---
 26 files changed, 170 insertions(+), 122 deletions(-)

diff --git a/Marlin/src/HAL/AVR/HAL.h b/Marlin/src/HAL/AVR/HAL.h
index ce15ed29fb..aa6a321320 100644
--- a/Marlin/src/HAL/AVR/HAL.h
+++ b/Marlin/src/HAL/AVR/HAL.h
@@ -122,12 +122,16 @@ inline uint8_t HAL_get_reset_source() { return MCUSR; }
 
 inline void HAL_reboot() {}  // reboot the board or restart the bootloader
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
-extern "C" {
-  int freeMemory();
-}
-#pragma GCC diagnostic pop
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+extern "C" int freeMemory();
+
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 // ADC
 #ifdef DIDR2
diff --git a/Marlin/src/HAL/DUE/HAL.h b/Marlin/src/HAL/DUE/HAL.h
index 88ace59575..395ca4ccc9 100644
--- a/Marlin/src/HAL/DUE/HAL.h
+++ b/Marlin/src/HAL/DUE/HAL.h
@@ -153,10 +153,16 @@ void HAL_init();
 //
 void _delay_ms(const int delay);
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 int freeMemory();
-#pragma GCC diagnostic pop
+
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 #ifdef __cplusplus
   extern "C" {
diff --git a/Marlin/src/HAL/ESP32/HAL.h b/Marlin/src/HAL/ESP32/HAL.h
index ebc16c9525..5ef13e0c21 100644
--- a/Marlin/src/HAL/ESP32/HAL.h
+++ b/Marlin/src/HAL/ESP32/HAL.h
@@ -100,10 +100,16 @@ inline void HAL_reboot() {}  // reboot the board or restart the bootloader
 
 void _delay_ms(int delay);
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 int freeMemory();
-#pragma GCC diagnostic pop
+
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 void analogWrite(pin_t pin, int value);
 
diff --git a/Marlin/src/HAL/ESP32/timers.h b/Marlin/src/HAL/ESP32/timers.h
index 7d35186b1c..98386e3980 100644
--- a/Marlin/src/HAL/ESP32/timers.h
+++ b/Marlin/src/HAL/ESP32/timers.h
@@ -91,9 +91,11 @@ typedef uint64_t hal_timer_t;
   #define HAL_PWM_TIMER_ISR() extern "C" void pwmTC_Handler()
 #endif
 
-extern "C" void tempTC_Handler();
-extern "C" void stepTC_Handler();
-extern "C" void pwmTC_Handler();
+extern "C" {
+  void tempTC_Handler();
+  void stepTC_Handler();
+  void pwmTC_Handler();
+}
 
 // ------------------------
 // Types
diff --git a/Marlin/src/HAL/HAL.h b/Marlin/src/HAL/HAL.h
index 5eca2f7eac..9eefda8fb1 100644
--- a/Marlin/src/HAL/HAL.h
+++ b/Marlin/src/HAL/HAL.h
@@ -23,6 +23,10 @@
 
 #include "platforms.h"
 
+#ifndef GCC_VERSION
+  #define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
+#endif
+
 #include HAL_PATH(.,HAL.h)
 
 #ifdef SERIAL_PORT_2
diff --git a/Marlin/src/HAL/LINUX/HAL.cpp b/Marlin/src/HAL/LINUX/HAL.cpp
index d7d7c2d2b4..ee9e31e140 100644
--- a/Marlin/src/HAL/LINUX/HAL.cpp
+++ b/Marlin/src/HAL/LINUX/HAL.cpp
@@ -27,18 +27,13 @@
 HalSerial usb_serial;
 
 // U8glib required functions
-extern "C" void u8g_xMicroDelay(uint16_t val) {
-  DELAY_US(val);
-}
-extern "C" void u8g_MicroDelay() {
-  u8g_xMicroDelay(1);
-}
-extern "C" void u8g_10MicroDelay() {
-  u8g_xMicroDelay(10);
-}
-extern "C" void u8g_Delay(uint16_t val) {
-  delay(val);
+extern "C" {
+  void u8g_xMicroDelay(uint16_t val) { DELAY_US(val); }
+  void u8g_MicroDelay()              { u8g_xMicroDelay(1); }
+  void u8g_10MicroDelay()            { u8g_xMicroDelay(10); }
+  void u8g_Delay(uint16_t val)       { delay(val); }
 }
+
 //************************//
 
 // return free heap space
diff --git a/Marlin/src/HAL/LINUX/HAL.h b/Marlin/src/HAL/LINUX/HAL.h
index 1c8dbfd4dc..729f6c856e 100644
--- a/Marlin/src/HAL/LINUX/HAL.h
+++ b/Marlin/src/HAL/LINUX/HAL.h
@@ -79,10 +79,16 @@ extern HalSerial usb_serial;
 inline void HAL_init() {}
 
 // Utility functions
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 int freeMemory();
-#pragma GCC diagnostic pop
+
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 // ADC
 #define HAL_ADC_VREF           5.0
diff --git a/Marlin/src/HAL/LINUX/include/Arduino.h b/Marlin/src/HAL/LINUX/include/Arduino.h
index e28b474ede..6aeb0db583 100644
--- a/Marlin/src/HAL/LINUX/include/Arduino.h
+++ b/Marlin/src/HAL/LINUX/include/Arduino.h
@@ -67,8 +67,11 @@ void cli(); // Disable
 void sei(); // Enable
 void attachInterrupt(uint32_t pin, void (*callback)(), uint32_t mode);
 void detachInterrupt(uint32_t pin);
-extern "C" void GpioEnableInt(uint32_t port, uint32_t pin, uint32_t mode);
-extern "C" void GpioDisableInt(uint32_t port, uint32_t pin);
+
+extern "C" {
+  void GpioEnableInt(uint32_t port, uint32_t pin, uint32_t mode);
+  void GpioDisableInt(uint32_t port, uint32_t pin);
+}
 
 // Program Memory
 #define pgm_read_ptr(addr)        (*((void**)(addr)))
@@ -92,9 +95,7 @@ using std::memcpy;
 #define strlen_P strlen
 
 // Time functions
-extern "C" {
-  void delay(const int milis);
-}
+extern "C" void delay(const int milis);
 void _delay_ms(const int delay);
 void delayMicroseconds(unsigned long);
 uint32_t millis();
diff --git a/Marlin/src/HAL/LPC1768/HAL.cpp b/Marlin/src/HAL/LPC1768/HAL.cpp
index 939f1e8a94..3614e95385 100644
--- a/Marlin/src/HAL/LPC1768/HAL.cpp
+++ b/Marlin/src/HAL/LPC1768/HAL.cpp
@@ -32,18 +32,13 @@
 uint32_t HAL_adc_reading = 0;
 
 // U8glib required functions
-extern "C" void u8g_xMicroDelay(uint16_t val) {
-  DELAY_US(val);
-}
-extern "C" void u8g_MicroDelay() {
-  u8g_xMicroDelay(1);
-}
-extern "C" void u8g_10MicroDelay() {
-  u8g_xMicroDelay(10);
-}
-extern "C" void u8g_Delay(uint16_t val) {
-  delay(val);
+extern "C" {
+  void u8g_xMicroDelay(uint16_t val) { DELAY_US(val); }
+  void u8g_MicroDelay()              { u8g_xMicroDelay(1); }
+  void u8g_10MicroDelay()            { u8g_xMicroDelay(10); }
+  void u8g_Delay(uint16_t val)       { delay(val); }
 }
+
 //************************//
 
 // return free heap space
diff --git a/Marlin/src/HAL/LPC1768/HAL.h b/Marlin/src/HAL/LPC1768/HAL.h
index cb637e715d..51a13389b1 100644
--- a/Marlin/src/HAL/LPC1768/HAL.h
+++ b/Marlin/src/HAL/LPC1768/HAL.h
@@ -107,10 +107,16 @@ extern "C" volatile uint32_t _millis;
 //
 // Utility functions
 //
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 int freeMemory();
-#pragma GCC diagnostic pop
+
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 //
 // ADC API
diff --git a/Marlin/src/HAL/LPC1768/MarlinSerial.cpp b/Marlin/src/HAL/LPC1768/MarlinSerial.cpp
index 5374e005d3..baad3f8f26 100644
--- a/Marlin/src/HAL/LPC1768/MarlinSerial.cpp
+++ b/Marlin/src/HAL/LPC1768/MarlinSerial.cpp
@@ -26,30 +26,19 @@
 
 #if USING_SERIAL_0
   MarlinSerial MSerial(LPC_UART0);
-  extern "C" void UART0_IRQHandler() {
-    MSerial.IRQHandler();
-  }
+  extern "C" void UART0_IRQHandler() { MSerial.IRQHandler(); }
 #endif
-
 #if USING_SERIAL_1
   MarlinSerial MSerial1((LPC_UART_TypeDef *) LPC_UART1);
-  extern "C" void UART1_IRQHandler() {
-    MSerial1.IRQHandler();
-  }
+  extern "C" void UART1_IRQHandler() { MSerial1.IRQHandler(); }
 #endif
-
 #if USING_SERIAL_2
   MarlinSerial MSerial2(LPC_UART2);
-  extern "C" void UART2_IRQHandler() {
-    MSerial2.IRQHandler();
-  }
+  extern "C" void UART2_IRQHandler() { MSerial2.IRQHandler(); }
 #endif
-
 #if USING_SERIAL_3
   MarlinSerial MSerial3(LPC_UART3);
-  extern "C" void UART3_IRQHandler() {
-    MSerial3.IRQHandler();
-  }
+  extern "C" void UART3_IRQHandler() { MSerial3.IRQHandler(); }
 #endif
 
 #endif // TARGET_LPC1768
diff --git a/Marlin/src/HAL/LPC1768/main.cpp b/Marlin/src/HAL/LPC1768/main.cpp
index 085b8ce04b..96faf54d7f 100644
--- a/Marlin/src/HAL/LPC1768/main.cpp
+++ b/Marlin/src/HAL/LPC1768/main.cpp
@@ -31,18 +31,18 @@
 #include <CDCSerial.h>
 #include <usb/mscuser.h>
 
-extern "C" {
-  #include <debug_frmwrk.h>
-}
-
 #include "../../inc/MarlinConfig.h"
 #include "../../core/millis_t.h"
 
 #include "../../sd/cardreader.h"
 
 extern uint32_t MSC_SD_Init(uint8_t pdrv);
-extern "C" int isLPC1769();
-extern "C" void disk_timerproc();
+
+extern "C" {
+  #include <debug_frmwrk.h>
+  extern "C" int isLPC1769();
+  extern "C" void disk_timerproc();
+}
 
 void SysTick_Callback() { disk_timerproc(); }
 
diff --git a/Marlin/src/HAL/SAMD51/HAL.h b/Marlin/src/HAL/SAMD51/HAL.h
index 7cb3635bd7..ff93101146 100644
--- a/Marlin/src/HAL/SAMD51/HAL.h
+++ b/Marlin/src/HAL/SAMD51/HAL.h
@@ -135,10 +135,16 @@ void HAL_idletask();
 //
 FORCE_INLINE void _delay_ms(const int delay_ms) { delay(delay_ms); }
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 int freeMemory();
-#pragma GCC diagnostic pop
+
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 #ifdef __cplusplus
   extern "C" {
diff --git a/Marlin/src/HAL/STM32/HAL.h b/Marlin/src/HAL/STM32/HAL.h
index c92c8890ea..16dc7a4539 100644
--- a/Marlin/src/HAL/STM32/HAL.h
+++ b/Marlin/src/HAL/STM32/HAL.h
@@ -140,15 +140,19 @@ void _delay_ms(const int delay);
 
 extern "C" char* _sbrk(int incr);
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
 
 static inline int freeMemory() {
   volatile char top;
   return &top - reinterpret_cast<char*>(_sbrk(0));
 }
 
-#pragma GCC diagnostic pop
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 //
 // ADC
diff --git a/Marlin/src/HAL/STM32F1/HAL.h b/Marlin/src/HAL/STM32F1/HAL.h
index 2880865dbb..06f75662cf 100644
--- a/Marlin/src/HAL/STM32F1/HAL.h
+++ b/Marlin/src/HAL/STM32F1/HAL.h
@@ -189,8 +189,10 @@ inline void HAL_reboot() {}  // reboot the board or restart the bootloader
 
 void _delay_ms(const int delay);
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
 
 /*
 extern "C" {
@@ -213,7 +215,9 @@ static int freeMemory() {
   return &top - reinterpret_cast<char*>(_sbrk(0));
 }
 
-#pragma GCC diagnostic pop
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 //
 // ADC
diff --git a/Marlin/src/HAL/STM32F1/timers.h b/Marlin/src/HAL/STM32F1/timers.h
index 6f360f6bfc..3e2e7775f1 100644
--- a/Marlin/src/HAL/STM32F1/timers.h
+++ b/Marlin/src/HAL/STM32F1/timers.h
@@ -129,8 +129,10 @@ timer_dev* get_timer_dev(int number);
   #define HAL_STEP_TIMER_ISR() extern "C" void stepTC_Handler()
 #endif
 
-extern "C" void tempTC_Handler();
-extern "C" void stepTC_Handler();
+extern "C" {
+  void tempTC_Handler();
+  void stepTC_Handler();
+}
 
 // ------------------------
 // Public Variables
diff --git a/Marlin/src/HAL/STM32_F4_F7/HAL.h b/Marlin/src/HAL/STM32_F4_F7/HAL.h
index 00a65de792..85fbf098ff 100644
--- a/Marlin/src/HAL/STM32_F4_F7/HAL.h
+++ b/Marlin/src/HAL/STM32_F4_F7/HAL.h
@@ -162,15 +162,19 @@ int freeMemory() {
 }
 */
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
 
 static inline int freeMemory() {
   volatile char top;
   return &top - reinterpret_cast<char*>(_sbrk(0));
 }
 
-#pragma GCC diagnostic pop
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 //
 // ADC
diff --git a/Marlin/src/HAL/STM32_F4_F7/STM32F4/timers.cpp b/Marlin/src/HAL/STM32_F4_F7/STM32F4/timers.cpp
index dc41f89131..8b753f7290 100644
--- a/Marlin/src/HAL/STM32_F4_F7/STM32F4/timers.cpp
+++ b/Marlin/src/HAL/STM32_F4_F7/STM32F4/timers.cpp
@@ -79,11 +79,9 @@ void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency) {
     HAL_TIM_Base_Start_IT(&TimerHandle[timer_num].handle);
 }
 
-extern "C" void TIM5_IRQHandler() {
-  ((void(*)())TimerHandle[0].callback)();
-}
-extern "C" void TIM7_IRQHandler() {
-  ((void(*)())TimerHandle[1].callback)();
+extern "C" {
+  void TIM5_IRQHandler() { ((void(*)())TimerHandle[0].callback)(); }
+  void TIM7_IRQHandler() { ((void(*)())TimerHandle[1].callback)(); }
 }
 
 void HAL_timer_enable_interrupt(const uint8_t timer_num) {
diff --git a/Marlin/src/HAL/STM32_F4_F7/STM32F7/timers.cpp b/Marlin/src/HAL/STM32_F4_F7/STM32F7/timers.cpp
index f7ded7454d..bc8f76af09 100644
--- a/Marlin/src/HAL/STM32_F4_F7/STM32F7/timers.cpp
+++ b/Marlin/src/HAL/STM32_F4_F7/STM32F7/timers.cpp
@@ -83,11 +83,9 @@ void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency) {
 }
 
 //forward the interrupt
-extern "C" void TIM5_IRQHandler() {
-  ((void(*)())timerConfig[0].callback)();
-}
-extern "C" void TIM7_IRQHandler() {
-  ((void(*)())timerConfig[1].callback)();
+extern "C" {
+  void TIM5_IRQHandler() { ((void(*)())timerConfig[0].callback)(); }
+  void TIM7_IRQHandler() { ((void(*)())timerConfig[1].callback)(); }
 }
 
 void HAL_timer_set_compare(const uint8_t timer_num, const uint32_t compare) {
diff --git a/Marlin/src/HAL/TEENSY31_32/HAL.h b/Marlin/src/HAL/TEENSY31_32/HAL.h
index 8ab358e9e1..9156aadb4d 100644
--- a/Marlin/src/HAL/TEENSY31_32/HAL.h
+++ b/Marlin/src/HAL/TEENSY31_32/HAL.h
@@ -97,12 +97,16 @@ inline void HAL_reboot() {}  // reboot the board or restart the bootloader
 
 FORCE_INLINE void _delay_ms(const int delay_ms) { delay(delay_ms); }
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
-extern "C" {
-  int freeMemory();
-}
-#pragma GCC diagnostic pop
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+extern "C" int freeMemory();
+
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 // ADC
 
diff --git a/Marlin/src/HAL/TEENSY31_32/timers.h b/Marlin/src/HAL/TEENSY31_32/timers.h
index 135b328830..61b8673596 100644
--- a/Marlin/src/HAL/TEENSY31_32/timers.h
+++ b/Marlin/src/HAL/TEENSY31_32/timers.h
@@ -74,10 +74,10 @@ typedef uint32_t hal_timer_t;
 #define DISABLE_TEMPERATURE_INTERRUPT() HAL_timer_disable_interrupt(TEMP_TIMER_NUM)
 
 #ifndef HAL_STEP_TIMER_ISR
-  #define HAL_STEP_TIMER_ISR()  extern "C" void ftm0_isr() //void TC3_Handler()
+  #define HAL_STEP_TIMER_ISR() extern "C" void ftm0_isr() //void TC3_Handler()
 #endif
 #ifndef HAL_TEMP_TIMER_ISR
-  #define HAL_TEMP_TIMER_ISR()  extern "C" void ftm1_isr() //void TC4_Handler()
+  #define HAL_TEMP_TIMER_ISR() extern "C" void ftm1_isr() //void TC4_Handler()
 #endif
 
 void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency);
diff --git a/Marlin/src/HAL/TEENSY35_36/HAL.h b/Marlin/src/HAL/TEENSY35_36/HAL.h
index 2b735d6224..04151e8378 100644
--- a/Marlin/src/HAL/TEENSY35_36/HAL.h
+++ b/Marlin/src/HAL/TEENSY35_36/HAL.h
@@ -103,12 +103,16 @@ inline void HAL_reboot() {}  // reboot the board or restart the bootloader
 
 FORCE_INLINE void _delay_ms(const int delay_ms) { delay(delay_ms); }
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
-extern "C" {
-  int freeMemory();
-}
-#pragma GCC diagnostic pop
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+extern "C" int freeMemory();
+
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 // ADC
 
diff --git a/Marlin/src/HAL/TEENSY35_36/timers.h b/Marlin/src/HAL/TEENSY35_36/timers.h
index 5c623cd801..99269ac657 100644
--- a/Marlin/src/HAL/TEENSY35_36/timers.h
+++ b/Marlin/src/HAL/TEENSY35_36/timers.h
@@ -73,10 +73,10 @@ typedef uint32_t hal_timer_t;
 #define DISABLE_TEMPERATURE_INTERRUPT() HAL_timer_disable_interrupt(TEMP_TIMER_NUM)
 
 #ifndef HAL_STEP_TIMER_ISR
-  #define HAL_STEP_TIMER_ISR()  extern "C" void ftm0_isr() //void TC3_Handler()
+  #define HAL_STEP_TIMER_ISR() extern "C" void ftm0_isr() //void TC3_Handler()
 #endif
 #ifndef HAL_TEMP_TIMER_ISR
-  #define HAL_TEMP_TIMER_ISR()  extern "C" void ftm1_isr() //void TC4_Handler()
+  #define HAL_TEMP_TIMER_ISR() extern "C" void ftm1_isr() //void TC4_Handler()
 #endif
 
 void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency);
diff --git a/Marlin/src/HAL/TEENSY40_41/HAL.h b/Marlin/src/HAL/TEENSY40_41/HAL.h
index 1e0043342d..28f511631e 100644
--- a/Marlin/src/HAL/TEENSY40_41/HAL.h
+++ b/Marlin/src/HAL/TEENSY40_41/HAL.h
@@ -120,12 +120,16 @@ uint8_t HAL_get_reset_source();
 
 FORCE_INLINE void _delay_ms(const int delay_ms) { delay(delay_ms); }
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
-extern "C" {
-  uint32_t freeMemory();
-}
-#pragma GCC diagnostic pop
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+extern "C" uint32_t freeMemory();
+
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic pop
+#endif
 
 // ADC
 
diff --git a/Marlin/src/HAL/TEENSY40_41/timers.h b/Marlin/src/HAL/TEENSY40_41/timers.h
index 7e4cd080cb..556333d7f4 100644
--- a/Marlin/src/HAL/TEENSY40_41/timers.h
+++ b/Marlin/src/HAL/TEENSY40_41/timers.h
@@ -72,14 +72,16 @@ typedef uint32_t hal_timer_t;
 #define DISABLE_TEMPERATURE_INTERRUPT() HAL_timer_disable_interrupt(TEMP_TIMER_NUM)
 
 #ifndef HAL_STEP_TIMER_ISR
-  #define HAL_STEP_TIMER_ISR()  extern "C" void stepTC_Handler() // GPT1_Handler()
+  #define HAL_STEP_TIMER_ISR() extern "C" void stepTC_Handler() // GPT1_Handler()
 #endif
 #ifndef HAL_TEMP_TIMER_ISR
-  #define HAL_TEMP_TIMER_ISR()  extern "C" void tempTC_Handler() // GPT2_Handler()
+  #define HAL_TEMP_TIMER_ISR() extern "C" void tempTC_Handler() // GPT2_Handler()
 #endif
 
-extern "C" void stepTC_Handler();
-extern "C" void tempTC_Handler();
+extern "C" {
+  void stepTC_Handler();
+  void tempTC_Handler();
+}
 
 void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency);
 
diff --git a/Marlin/src/libs/duration_t.h b/Marlin/src/libs/duration_t.h
index 9c1d72dfaf..bd654b7bad 100644
--- a/Marlin/src/libs/duration_t.h
+++ b/Marlin/src/libs/duration_t.h
@@ -106,8 +106,10 @@ struct duration_t {
     return this->value;
   }
 
-  #pragma GCC diagnostic push
-  #pragma GCC diagnostic ignored "-Wformat-overflow"
+  #if GCC_VERSION <= 50000
+    #pragma GCC diagnostic push
+    #pragma GCC diagnostic ignored "-Wformat-overflow"
+  #endif
 
   /**
    * @brief Formats the duration as a string
@@ -167,5 +169,7 @@ struct duration_t {
     }
   }
 
-  #pragma GCC diagnostic pop
+  #if GCC_VERSION <= 50000
+    #pragma GCC diagnostic pop
+  #endif
 };