Misra 17.7: the value returned by a function having non-void return shall be used (commaai#237)

* Fixed Misra 17.7 violations except for can_push

Author: rbiasini

board/drivers/can.h

@@ -72,8 +72,8 @@ bool can_pop(can_ring *q, CAN_FIFOMailBox_TypeDef *elem) {
   return ret;
 }
 
-int can_push(can_ring *q, CAN_FIFOMailBox_TypeDef *elem) {
-  int ret = 0;
+bool can_push(can_ring *q, CAN_FIFOMailBox_TypeDef *elem) {
+  bool ret = false;
   uint32_t next_w_ptr;
 
   enter_critical_section();
@@ -82,10 +82,10 @@ int can_push(can_ring *q, CAN_FIFOMailBox_TypeDef *elem) {
   if (next_w_ptr != q->r_ptr) {
     q->elems[q->w_ptr] = *elem;
     q->w_ptr = next_w_ptr;
-    ret = 1;
+    ret = true;
   }
   exit_critical_section();
-  if (ret == 0) {
+  if (!ret) {
     can_overflow_cnt++;
     #ifdef DEBUG
       puts("can_push failed!\n");

board/drivers/spi.h

@@ -85,7 +85,7 @@ uint8_t spi_tx_buf[0x44];
 // SPI RX
 void DMA2_Stream2_IRQHandler(void) {
   int *resp_len = (int*)spi_tx_buf;
-  memset(spi_tx_buf, 0xaa, 0x44);
+  (void)memset(spi_tx_buf, 0xaa, 0x44);
   *resp_len = spi_cb_rx(spi_buf, 0x14, spi_tx_buf+4);
   #ifdef DEBUG_SPI
     puts("SPI write: ");

board/drivers/usb.h

@@ -807,7 +807,7 @@ void usb_irqhandler(void) {
     if (((rxst & USB_OTG_GRXSTSP_PKTSTS) >> 17) == STS_DATA_UPDT) {
       int endpoint = (rxst & USB_OTG_GRXSTSP_EPNUM);
       int len = (rxst & USB_OTG_GRXSTSP_BCNT) >> 4;
-      USB_ReadPacket(&usbdata, len);
+      (void)USB_ReadPacket(&usbdata, len);
       #ifdef DEBUG_USB
         puts("  data ");
         puth(len);
@@ -823,7 +823,7 @@ void usb_irqhandler(void) {
         usb_cb_ep3_out(usbdata, len, 1);
       }
     } else if (((rxst & USB_OTG_GRXSTSP_PKTSTS) >> 17) == STS_SETUP_UPDT) {
-      USB_ReadPacket(&setup, 8);
+      (void)USB_ReadPacket(&setup, 8);
       #ifdef DEBUG_USB
         puts("  setup ");
         hexdump(&setup, 8);

board/main.c

@@ -33,7 +33,7 @@
 void debug_ring_callback(uart_ring *ring) {
   char rcv;
   while (getc(ring, &rcv)) {
-    putc(ring, rcv);
+    (void)putc(ring, rcv);  // misra-c2012-17.7: cast to void is ok: debug function
 
     // jump to DFU flash
     if (rcv == 'z') {
@@ -212,7 +212,7 @@ int usb_cb_control_msg(USB_Setup_TypeDef *setup, uint8_t *resp, bool hardwired)
     case 0xd0:
       // addresses are OTP
       if (setup->b.wValue.w == 1) {
-        memcpy(resp, (void *)0x1fff79c0, 0x10);
+        (void)memcpy(resp, (void *)0x1fff79c0, 0x10);
         resp_len = 0x10;
       } else {
         get_provision_chunk(resp);
@@ -248,7 +248,7 @@ int usb_cb_control_msg(USB_Setup_TypeDef *setup, uint8_t *resp, bool hardwired)
     // **** 0xd6: get version
     case 0xd6:
       COMPILE_TIME_ASSERT(sizeof(gitversion) <= MAX_RESP_LEN);
-      memcpy(resp, gitversion, sizeof(gitversion));
+      (void)memcpy(resp, gitversion, sizeof(gitversion));
       resp_len = sizeof(gitversion)-1;
       break;
     // **** 0xd8: reset ST
@@ -296,27 +296,31 @@ int usb_cb_control_msg(USB_Setup_TypeDef *setup, uint8_t *resp, bool hardwired)
       // and it's blocked over WiFi
       // Allow ELM security mode to be set over wifi.
       if (hardwired || (setup->b.wValue.w == SAFETY_NOOUTPUT) || (setup->b.wValue.w == SAFETY_ELM327)) {
-        safety_set_mode(setup->b.wValue.w, (int16_t)setup->b.wIndex.w);
-        if (safety_ignition_hook() != -1) {
-          // if the ignition hook depends on something other than the started GPIO
-          // we have to disable power savings (fix for GM and Tesla)
-          set_power_save_state(POWER_SAVE_STATUS_DISABLED);
-        }
-        #ifndef EON
-          // always LIVE on EON
-          switch (setup->b.wValue.w) {
-            case SAFETY_NOOUTPUT:
-              can_silent = ALL_CAN_SILENT;
-              break;
-            case SAFETY_ELM327:
-              can_silent = ALL_CAN_BUT_MAIN_SILENT;
-              break;
-            default:
-              can_silent = ALL_CAN_LIVE;
-              break;
+        int err = safety_set_mode(setup->b.wValue.w, (int16_t)setup->b.wIndex.w);
+        if (err == -1) {
+          puts("Error: safety set mode failed\n");
+        } else {
+          #ifndef EON
+            // always LIVE on EON
+            switch (setup->b.wValue.w) {
+              case SAFETY_NOOUTPUT:
+                can_silent = ALL_CAN_SILENT;
+                break;
+              case SAFETY_ELM327:
+                can_silent = ALL_CAN_BUT_MAIN_SILENT;
+                break;
+              default:
+                can_silent = ALL_CAN_LIVE;
+                break;
+            }
+          #endif
+          if (safety_ignition_hook() != -1) {
+            // if the ignition hook depends on something other than the started GPIO
+            // we have to disable power savings (fix for GM and Tesla)
+            set_power_save_state(POWER_SAVE_STATUS_DISABLED);
           }
-        #endif
-        can_init_all();
+          can_init_all();
+        }
       }
       break;
     // **** 0xdd: enable can forwarding

board/provision.h

@@ -5,9 +5,9 @@
 // SHA1 checksum = 0x1C - 0x20
 
 void get_provision_chunk(uint8_t *resp) {
-  memcpy(resp, (void *)0x1fff79e0, PROVISION_CHUNK_LEN);
+  (void)memcpy(resp, (void *)0x1fff79e0, PROVISION_CHUNK_LEN);
   if (memcmp(resp, "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff", 0x20) == 0) {
-    memcpy(resp, "unprovisioned\x00\x00\x00testing123\x00\x00\xa3\xa6\x99\xec", 0x20);
+    (void)memcpy(resp, "unprovisioned\x00\x00\x00testing123\x00\x00\xa3\xa6\x99\xec", 0x20);
   }
 }