Cortex M3 QEMU demo now builds with -Wall -Wextra (#727)

* Added -Wall -Wextra to the Coretex M3 QEMU demo

* Fixed warnings & errors in Cortex M3 QEMU demo

* Fixed the FULL demo to compile with full errors.

* Update FreeRTOS/Demo/CORTEX_M3_MPS2_QEMU_GCC/init/startup.c

Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>

* Applied the ( void ) r0 pattern to prvGetRegisterFromStack

Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>

FreeRTOS/Demo/CORTEX_M3_MPS2_QEMU_GCC/Makefile

@@ -71,6 +71,7 @@ LDFLAGS += -Xlinker -Map=${BUILD_DIR}/output.map
 
 CFLAGS += -nostartfiles -mthumb -mcpu=cortex-m3 -Wno-error=implicit-function-declaration
 CFLAGS += -Wno-builtin-declaration-mismatch -Werror
+CFLAGS += -Wall -Wextra
 
 ifeq ($(DEBUG), 1)
     CFLAGS += -ggdb3 -Og

FreeRTOS/Demo/CORTEX_M3_MPS2_QEMU_GCC/init/startup.c

@@ -96,6 +96,15 @@ void prvGetRegistersFromStack( uint32_t * pulFaultStackAddress )
     for( ; ; )
     {
     }
+    /* remove the warning: variable <x> is set but not used */
+    ( void ) r0;
+    ( void ) r1;
+    ( void ) r2;
+    ( void ) r3;
+    ( void ) r12;
+    ( void ) lr;
+    ( void ) pc;
+    ( void ) psr;
 }
 
 static void Default_Handler( void ) __attribute__( ( naked ) );
@@ -114,7 +123,7 @@ void Default_Handler( void )
         "NVIC_INT_CTRL_CONST: .word 0xe000ed04\n"
     );
 }
-static void HardFault_Handler( void ) __attribute__( ( naked ) );
+static void Default_Handler2( void ) __attribute__( ( naked ) );
 void Default_Handler2( void )
 {
     __asm volatile
@@ -199,7 +208,7 @@ void _start( void )
     exit( 0 );
 }
 
-__attribute__( ( naked ) ) void exit( int status )
+__attribute__( ( naked ) ) void exit(__attribute__((unused)) int status )
 {
     /* Force qemu to exit using ARM Semihosting */
     __asm volatile (

FreeRTOS/Demo/CORTEX_M3_MPS2_QEMU_GCC/main.c

@@ -68,7 +68,6 @@ int main()
             #error "Invalid Selection...\nPlease Select a Demo application from the main command"
         }
     #endif /* if ( mainCREATE_SIMPLE_BLINKY_DEMO_ONLY == 1 ) */
-        snprint
     return 0;
 }
 
@@ -108,15 +107,6 @@ void vApplicationStackOverflowHook( TaskHandle_t pxTask,
 
 void vApplicationIdleHook( void )
 {
-    volatile size_t xFreeHeapSpace;
-
-    /* This is just a trivial example of an idle hook.  It is called on each
-     * cycle of the idle task.  It must *NOT* attempt to block.  In this case the
-     * idle task just queries the amount of FreeRTOS heap that remains.  See the
-     * memory management section on the https://www.FreeRTOS.org web site for memory
-     * management options.  If there is a lot of heap memory free then the
-     * configTOTAL_HEAP_SIZE value in FreeRTOSConfig.h can be reduced to free up
-     * RAM. */
     #if ( mainCREATE_FULL_DEMO_ONLY == 1 )
         {
             /* Call the idle task processing used by the full demo.  The simple

FreeRTOS/Demo/CORTEX_M3_MPS2_QEMU_GCC/main_full.c

@@ -221,6 +221,7 @@ int main_full( void )
     xTaskCreate( prvDemoQueueSpaceFunctions, "QSpace", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
     xTaskCreate( prvPermanentlyBlockingSemaphoreTask, "BlockSem", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
     xTaskCreate( prvPermanentlyBlockingNotificationTask, "BlockNoti", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
+	xTaskCreate( prvDemonstrateChangingTimerReloadMode, "TimerMode", configMINIMAL_STACK_SIZE, NULL, configMAX_PRIORITIES - 1, NULL );
 
     vStartMessageBufferTasks( configMINIMAL_STACK_SIZE );
     vStartStreamBufferTasks();
@@ -270,7 +271,6 @@ static void prvCheckTask( void * pvParameters )
 {
     TickType_t xNextWakeTime;
     const TickType_t xCycleFrequency = pdMS_TO_TICKS( 10000UL );
-    HeapStats_t xHeapStats;
 
     /* Just to remove compiler warning. */
     ( void ) pvParameters;
@@ -428,7 +428,7 @@ static void prvCheckTask( void * pvParameters )
             }
         #endif /* configSUPPORT_STATIC_ALLOCATION */
 
-        printf( "%s - tick count %u \r\n",
+        printf( "%s - tick count %lu \r\n",
                 pcStatusMessage,
                 xTaskGetTickCount() );
 
@@ -582,10 +582,10 @@ void vFullDemoTickHookFunction( void )
 static void prvPendedFunction( void * pvParameter1,
                                uint32_t ulParameter2 )
 {
-    static intptr_t ulLastParameter1 = 1000UL, ulLastParameter2 = 0UL;
+    static uintptr_t ulLastParameter1 = 1000UL, ulLastParameter2 = 0UL;
-    intptr_t ulParameter1;
+    uintptr_t ulParameter1;
 
-    ulParameter1 = ( intptr_t ) pvParameter1;
+    ulParameter1 = ( uintptr_t ) pvParameter1;
 
     /* Ensure the parameters are as expected. */
     configASSERT( ulParameter1 == ( ulLastParameter1 + 1 ) );

FreeRTOS/Demo/CORTEX_M3_MPS2_QEMU_GCC/syscall.c

@@ -66,7 +66,7 @@ void uart_init()
  * @todo  implement if necessary
  *
  */
-int _fstat( int file )
+int _fstat(__attribute__((unused)) int file )
 {
     return 0;
 }
@@ -76,9 +76,9 @@ int _fstat( int file )
  * @todo  implement if necessary
  *
  */
-int _read( int file,
+int _read(__attribute__((unused)) int file,
-           char * buf,
+          __attribute__((unused)) char * buf,
-           int len )
+          __attribute__((unused)) int len )
 {
     return -1;
 }
@@ -91,9 +91,9 @@ int _read( int file,
  * @param [in] len   length of the buffer
  * @returns the number of bytes written
  */
-int _write( int file,
+int _write(__attribute__((unused)) int file,
-            char * buf,
+           __attribute__((unused)) char * buf,
-            int len )
+           int len )
 {
     int todo;