Suppress MISRA C:2012 rule 21.6 for snprintf (#877)

Suppress MISRA C:2012 rule 21.6 for snprintf

2 files changed, 32 insertions, 5 deletions

diff --git a/MISRA.md b/MISRA.md
index 1cca337ff..734a51291 100644
--- a/MISRA.md
+++ b/MISRA.md
@@ -107,6 +107,15 @@ _Ref 11.5.5_
    because data storage buffers are implemented as uint8_t arrays for the
    ease of sizing, alignment and access.
 
+#### Rule 21.6
+
+MISRA C-2012 Rule 21.6: The Standard Library input/output functions shall not
+be used.
+
+_Ref 21.6.1_
+ - The Standard Library function snprintf is used in vTaskListTasks and
+   vTaskGetRunTimeStatistics APIs, both of which are utility functions only and
+   are not considered part of core kernel implementation.
 
 ### MISRA configuration
 
diff --git a/tasks.c b/tasks.c
index 7c05bd531..1bb8a05a9 100644
--- a/tasks.c
+++ b/tasks.c
@@ -7348,6 +7348,9 @@ static void prvResetNextTaskUnblockTime( void )
                     {
                         /* Write the rest of the string. */
                         #if ( ( configUSE_CORE_AFFINITY == 1 ) && ( configNUMBER_OF_CORES > 1 ) )
+                            /* MISRA Ref 21.6.1 [snprintf for utility] */
+                            /* More details at: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/main/MISRA.md#rule-216 */
+                            /* coverity[misra_c_2012_rule_21_6_violation] */
                             iSnprintfReturnValue = snprintf( pcWriteBuffer,
                                                              uxBufferLength - uxConsumedBufferLength,
                                                              "\t%c\t%u\t%u\t%u\t0x%x\r\n",
@@ -7355,15 +7358,18 @@ static void prvResetNextTaskUnblockTime( void )
                                                              ( unsigned int ) pxTaskStatusArray[ x ].uxCurrentPriority,
                                                              ( unsigned int ) pxTaskStatusArray[ x ].usStackHighWaterMark,
                                                              ( unsigned int ) pxTaskStatusArray[ x ].xTaskNumber,
-                                                             ( unsigned int ) pxTaskStatusArray[ x ].uxCoreAffinityMask ); /*lint !e586 sprintf() allowed as this is compiled with many compilers and this is a utility function only - not part of the core kernel implementation. */
+                                                             ( unsigned int ) pxTaskStatusArray[ x ].uxCoreAffinityMask );
                         #else /* ( ( configUSE_CORE_AFFINITY == 1 ) && ( configNUMBER_OF_CORES > 1 ) ) */
+                            /* MISRA Ref 21.6.1 [snprintf for utility] */
+                            /* More details at: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/main/MISRA.md#rule-216 */
+                            /* coverity[misra_c_2012_rule_21_6_violation] */
                             iSnprintfReturnValue = snprintf( pcWriteBuffer,
                                                              uxBufferLength - uxConsumedBufferLength,
                                                              "\t%c\t%u\t%u\t%u\r\n",
                                                              cStatus,
                                                              ( unsigned int ) pxTaskStatusArray[ x ].uxCurrentPriority,
                                                              ( unsigned int ) pxTaskStatusArray[ x ].usStackHighWaterMark,
-                                                             ( unsigned int ) pxTaskStatusArray[ x ].xTaskNumber ); /*lint !e586 sprintf() allowed as this is compiled with many compilers and this is a utility function only - not part of the core kernel implementation. */
+                                                             ( unsigned int ) pxTaskStatusArray[ x ].xTaskNumber );
                         #endif /* ( ( configUSE_CORE_AFFINITY == 1 ) && ( configNUMBER_OF_CORES > 1 ) ) */
                         uxCharsWrittenBySnprintf = prvSnprintfReturnValueToCharsWritten( iSnprintfReturnValue, uxBufferLength - uxConsumedBufferLength );
 
@@ -7496,21 +7502,27 @@ static void prvResetNextTaskUnblockTime( void )
                             {
                                 #ifdef portLU_PRINTF_SPECIFIER_REQUIRED
                                 {
+                                    /* MISRA Ref 21.6.1 [snprintf for utility] */
+                                    /* More details at: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/main/MISRA.md#rule-216 */
+                                    /* coverity[misra_c_2012_rule_21_6_violation] */
                                     iSnprintfReturnValue = snprintf( pcWriteBuffer,
                                                                      uxBufferLength - uxConsumedBufferLength,
                                                                      "\t%lu\t\t%lu%%\r\n",
                                                                      pxTaskStatusArray[ x ].ulRunTimeCounter,
                                                                      ulStatsAsPercentage );
                                 }
-                                #else
+                                #else /* ifdef portLU_PRINTF_SPECIFIER_REQUIRED */
                                 {
                                     /* sizeof( int ) == sizeof( long ) so a smaller
                                      * printf() library can be used. */
+                                    /* MISRA Ref 21.6.1 [snprintf for utility] */
+                                    /* More details at: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/main/MISRA.md#rule-216 */
+                                    /* coverity[misra_c_2012_rule_21_6_violation] */
                                     iSnprintfReturnValue = snprintf( pcWriteBuffer,
                                                                      uxBufferLength - uxConsumedBufferLength,
                                                                      "\t%u\t\t%u%%\r\n",
                                                                      ( unsigned int ) pxTaskStatusArray[ x ].ulRunTimeCounter,
-                                                                     ( unsigned int ) ulStatsAsPercentage ); /*lint !e586 sprintf() allowed as this is compiled with many compilers and this is a utility function only - not part of the core kernel implementation. */
+                                                                     ( unsigned int ) ulStatsAsPercentage );
                                 }
                                 #endif /* ifdef portLU_PRINTF_SPECIFIER_REQUIRED */
                             }
@@ -7520,6 +7532,9 @@ static void prvResetNextTaskUnblockTime( void )
                                  * consumed less than 1% of the total run time. */
                                 #ifdef portLU_PRINTF_SPECIFIER_REQUIRED
                                 {
+                                    /* MISRA Ref 21.6.1 [snprintf for utility] */
+                                    /* More details at: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/main/MISRA.md#rule-216 */
+                                    /* coverity[misra_c_2012_rule_21_6_violation] */
                                     iSnprintfReturnValue = snprintf( pcWriteBuffer,
                                                                      uxBufferLength - uxConsumedBufferLength,
                                                                      "\t%lu\t\t<1%%\r\n",
@@ -7529,10 +7544,13 @@ static void prvResetNextTaskUnblockTime( void )
                                 {
                                     /* sizeof( int ) == sizeof( long ) so a smaller
                                      * printf() library can be used. */
+                                    /* MISRA Ref 21.6.1 [snprintf for utility] */
+                                    /* More details at: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/main/MISRA.md#rule-216 */
+                                    /* coverity[misra_c_2012_rule_21_6_violation] */
                                     iSnprintfReturnValue = snprintf( pcWriteBuffer,
                                                                      uxBufferLength - uxConsumedBufferLength,
                                                                      "\t%u\t\t<1%%\r\n",
-                                                                     ( unsigned int ) pxTaskStatusArray[ x ].ulRunTimeCounter ); /*lint !e586 sprintf() allowed as this is compiled with many compilers and this is a utility function only - not part of the core kernel implementation. */
+                                                                     ( unsigned int ) pxTaskStatusArray[ x ].ulRunTimeCounter );
                                 }
                                 #endif /* ifdef portLU_PRINTF_SPECIFIER_REQUIRED */
                             }