Fix GCC 10.1 errors and warnings

lib/esp-epaper-29-ws-20171230-gemu-1.1/src/epd2in9.cpp

@@ -81,6 +81,7 @@ int16_t Epd::Begin(int16_t cs,int16_t mosi,int16_t sclk) {
   cs_pin=cs;
   mosi_pin=mosi;
   sclk_pin=sclk;
+  return 0;
 }
 
 

lib/esp-epaper-29-ws-20171230-gemu-1.1/src/epd4in2.cpp

@@ -94,6 +94,7 @@ int16_t Epd42::Begin(int16_t cs,int16_t mosi,int16_t sclk) {
   cs_pin=cs;
   mosi_pin=mosi;
   sclk_pin=sclk;
+  return 0;
 }
 
 void Epd42::Init(int8_t p) {

lib/esp-epaper-29-ws-20171230-gemu-1.1/src/epdpaint.cpp

@@ -38,7 +38,7 @@ void Paint::DisplayOnff(int8_t on) {
 }
 
 int16_t Paint::Begin(int16_t p1,int16_t p2,int16_t p3) {
-
+  return 0;
 }
 
 void Paint::Updateframe() {

lib/esp-knx-ip-0.5.2/esp-knx-ip.cpp

@@ -247,6 +247,7 @@ callback_assignment_id_t ESPKNXIP::__callback_register_assignment(address_t addr
       return id;
     }
   }
+  return -1;
 }
 
 void ESPKNXIP::__callback_delete_assignment(callback_assignment_id_t id)
@@ -358,6 +359,7 @@ callback_id_t ESPKNXIP::callback_register(String name, callback_fptr_t cb, void
       return id;
     }
   }
+  return -1;
 }
 
 void ESPKNXIP::callback_deregister(callback_id_t id)

lib/esp-knx-ip-0.5.2/esp-knx-ip.h

@@ -270,7 +270,8 @@ typedef struct __cemi_msg
   uint8_t additional_info_len;
   union
   {
-    cemi_addi_t additional_info[];
+//    cemi_addi_t additional_info[];   // Errors in GCC 10.1
+    cemi_addi_t additional_info[10];   // Changed to arbitrary number to fix compilation
     cemi_service_t service_information;
   } data;
 } cemi_msg_t;

tasmota/support_float.ino

@@ -218,6 +218,7 @@ float cos_52(float x)
     case 2: return -cos_52s(x-(float)f_pi);
     case 3: return  cos_52s((float)f_twopi - x);
   }
+  return 0.0;  // Never reached. Fixes compiler warning
 }
 //
 // The sine is just cosine shifted a half-f_pi, so
@@ -278,6 +279,7 @@ float tan_56(float x)
     case 6: return -1.0f / tan_56s((x-(float)f_threehalfpi)   * (float)f_four_over_pi);
     case 7: return -       tan_56s(((float)f_twopi - x)       * (float)f_four_over_pi);
   }
+  return 0.0;  // Never reached. Fixes compiler warning
 }
 
 // *******************************************************************

tasmota/support_network.ino

@@ -99,6 +99,7 @@ char* NetworkHostname(void) {
   }
 #endif
 #endif
+  return nullptr;  // Never reached. Fix GCC10 warning
 }
 
 IPAddress NetworkAddress(void) {
@@ -112,6 +113,7 @@ IPAddress NetworkAddress(void) {
   }
 #endif
 #endif
+  return 0;  // Never reached. Fix GCC10 warning
 }
 
 String NetworkMacAddress(void) {
@@ -125,4 +127,5 @@ String NetworkMacAddress(void) {
   }
 #endif
 #endif
+  return "";  // Never reached. Fix GCC10 warning
 }

tasmota/xdrv_04_light.ino

@@ -477,7 +477,7 @@ class LightStateClass {
       if (w) { *w = ct_channels_on  ? changeUIntScale(_ww, 0, 255, 0, _briCT) : 0; }
     }
 
-    uint8_t getChannels(uint8_t *channels) {
+    void getChannels(uint8_t *channels) {
       getActualRGBCW(&channels[0], &channels[1], &channels[2], &channels[3], &channels[4]);
     }
 

tasmota/xdrv_10_rules.ino

@@ -294,6 +294,7 @@ String GetRule(uint32_t idx) {
     return rule;
 #endif
   }
+  return "";  // Fix GCC10 warning
 }
 
 #ifdef USE_UNISHOX_COMPRESSION

tasmota/xdrv_22_sonoff_ifan.ino

@@ -156,7 +156,8 @@ void SonoffIfanReceived(void)
 
 bool SonoffIfanSerialInput(void)
 {
-  if (SONOFF_IFAN03 == my_module_type) {
+  if (SONOFF_IFAN03 != my_module_type) { return false; }
+
   if (0xAA == serial_in_byte) {               // 0xAA - Start of text
     serial_in_byte_counter = 0;
     ifan_receive_flag = true;
@@ -187,7 +188,6 @@ bool SonoffIfanSerialInput(void)
     serial_in_byte = 0;
   }
   return false;
-  }
 }
 
 /*********************************************************************************************\

tasmota/xnrg_02_cse7766.ino

@@ -141,7 +141,7 @@ void CseReceived(void) {
   }
 }
 
-bool CseSerialInput(void) {
+void CseSerialInput(void) {
   while (CseSerial->available()) {
     yield();
     uint8_t serial_in_byte = CseSerial->read();
@@ -158,7 +158,7 @@ bool CseSerialInput(void) {
           Energy.data_valid[0] = 0;
           CseReceived();
           Cse.received = false;
-          return true;
+          return;
         } else {
           do {  // Sync buffer with data (issue #1907 and #3425)
             memmove(Cse.rx_buffer, Cse.rx_buffer +1, 24);

tasmota/xnrg_14_bl0940.ino

@@ -121,7 +121,7 @@ void Bl0940Received(void) {
   }
 }
 
-bool Bl0940SerialInput(void) {
+void Bl0940SerialInput(void) {
   while (Bl0940Serial->available()) {
     yield();
     uint8_t serial_in_byte = Bl0940Serial->read();
@@ -142,7 +142,7 @@ bool Bl0940SerialInput(void) {
           Energy.data_valid[0] = 0;
           Bl0940Received();
           Bl0940.received = false;
-          return true;
+          return;
         } else {
           do {  // Sync buffer with data (issue #1907 and #3425)
             memmove(Bl0940.rx_buffer, Bl0940.rx_buffer +1, BL0940_BUFFER_SIZE -1);