Fix errors if LED_BUILTIN is not defined

Author: ArminJo

src/IRSend.cpp.h

@@ -77,6 +77,9 @@ void IRsend::begin(bool aEnableLEDFeedback, uint8_t aLEDFeedbackPin) {
         && !(defined(NRF5) || defined(ARDUINO_ARCH_NRF52840)) && !defined(ARDUINO_ARCH_SAMD) \
         && !defined(ESP32) && !defined(ESP8266) && !defined(MEGATINYCORE) \
     && !(defined(__STM32F1__) || defined(ARDUINO_ARCH_STM32F1)) && !(defined(STM32F1xx) || defined(ARDUINO_ARCH_STM32))
+    /*
+     * This error shows up, if this function is really used/called by the user program. This check works only if lto is enabled.
+     */
     UsageError(
             "Error: You must use begin(<sendPin>, <EnableLEDFeedback>, <LEDFeedbackPin>) if SEND_PWM_BY_TIMER is not defined or USE_NO_SEND_PWM is defined!");
 #endif

src/IRremoteInt.h

@@ -105,6 +105,10 @@ struct irparams_struct {
 #  define TRACE_PRINTLN(...) void()
 #endif
 
+#if (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4)
+#define COMPILER_HAS_PRAGMA_MESSAGE
+#endif
+
 /****************************************************
  *                     RECEIVING
  ****************************************************/

src/private/IRFeedbackLEDDefs.h

@@ -37,10 +37,6 @@
 #define FEEDBACK_LED_ON()   (PORTC |= B10000000)
 #define FEEDBACK_LED_OFF()  (PORTC &= B01111111)
 
-#elif defined(__AVR_ATmega32U4__) || defined(__AVR_ATmega8U2__) || defined(__AVR_ATmega16U2__)  || defined(__AVR_ATmega32U2__)
-#define FEEDBACK_LED_ON()   (digitalWrite(LED_BUILTIN, HIGH))
-#define FEEDBACK_LED_OFF()  (digitalWrite(LED_BUILTIN, LOW))
-
 // Arduino Uno, Nano etc
 #elif defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328PB__) || defined(__AVR_ATmega168__)
 #define FEEDBACK_LED_ON()   (PORTB |= B00100000)
@@ -64,8 +60,8 @@
 
 #elif defined(PARTICLE)
 #define LED_BUILTIN       D7
-#define FEEDBACK_LED_ON()  digitalWrite(LED_BUILTIN,1)
-#define FEEDBACK_LED_OFF() digitalWrite(LED_BUILTIN,0)
+#define FEEDBACK_LED_ON()  digitalWrite(LED_BUILTIN, 1)
+#define FEEDBACK_LED_OFF() digitalWrite(LED_BUILTIN, 0)
 
 // Arduino Zero and BluePill and ESP8266 have an LED which is active low
 #elif defined(__STM32F1__) || defined(STM32F1xx) || defined(ESP8266)
@@ -76,9 +72,10 @@
 /*
  * Default case suitable for most boards
  */
+#  if defined(LED_BUILTIN)
 #define FEEDBACK_LED_ON()   digitalWrite(LED_BUILTIN, HIGH)
 #define FEEDBACK_LED_OFF()  digitalWrite(LED_BUILTIN, LOW)
-#  ifndef LED_BUILTIN
+#  else
 /*
  * print a warning
  */