Meaningful error codes instead of plain -1

libuavcan/src/node/scheduler.cpp

@@ -157,7 +157,7 @@ int Scheduler::spin(MonotonicTime deadline)
     if (inside_spin_)  // Preventing recursive calls
     {
         assert(0);
-        return -1;
+        return -ErrRecursiveCall;
     }
     inside_spin_ = true;
 

libuavcan/src/protocol/data_type_info_provider.cpp

@@ -84,7 +84,7 @@ void DataTypeInfoProvider::handleGetDataTypeInfoRequest(const protocol::GetDataT
 
 int DataTypeInfoProvider::start()
 {
-    int res = -1;
+    int res = 0;
 
     res = cats_srv_.start(
         ComputeAggregateTypeSignatureCallback(this, &DataTypeInfoProvider::handleComputeAggregateTypeSignatureRequest));

libuavcan/src/protocol/global_time_sync_master.cpp

@@ -108,12 +108,12 @@ int GlobalTimeSyncMaster::init()
         GlobalDataTypeRegistry::instance().find(DataTypeKindMessage, protocol::GlobalTimeSync::getDataTypeFullName());
     if (desc == NULL)
     {
-        return -1;
+        return -ErrUnknownDataType;
     }
     dtid_ = desc->getID();
 
     // Iface master array
-    int res = -1;
+    int res = -ErrLogic;
     for (uint8_t i = 0; i < MaxCanIfaces; i++)
     {
         if (!iface_masters_[i].isConstructed())

libuavcan/src/protocol/node_initializer.cpp

@@ -105,7 +105,7 @@ int NodeInitializer::checkOneNodeOneDataTypeKind(NodeID nid, DataTypeKind kind)
     }
     if (!last_cats_request_ok_)
     {
-        return -1;
+        return -ErrFailure;
     }
     return 0;
 }

libuavcan/src/protocol/node_status_provider.cpp

@@ -59,15 +59,13 @@ void NodeStatusProvider::handleGetNodeInfoRequest(const protocol::GetNodeInfo::R
 
 int NodeStatusProvider::startAndPublish()
 {
-    int res = -1;
-
     if (!isNodeInfoInitialized())
     {
         UAVCAN_TRACE("NodeStatusProvider", "Node info was not initialized");
-        return -1;
+        return -ErrNotInited;
     }
 
-    res = publish(); // Initial broadcast
+    int res = publish(); // Initial broadcast
     if (res < 0)
     {
         goto fail;

libuavcan/src/protocol/param_server.cpp

@@ -73,7 +73,7 @@ int ParamServer::start(IParamManager* manager)
 {
     if (manager == NULL)
     {
-        return -1;
+        return -ErrInvalidParam;
     }
     manager_ = manager;
 

libuavcan/src/transport/can_io.cpp

@@ -219,7 +219,7 @@ int CanIOManager::sendToIface(int iface_index, const CanFrame& frame, MonotonicT
     if (iface == NULL)
     {
         assert(0);   // Nonexistent interface
-        return -1;
+        return -ErrLogic;
     }
     const int res = iface->send(frame, tx_deadline, flags);
     if (res != 1)
@@ -311,7 +311,7 @@ int CanIOManager::send(const CanFrame& frame, MonotonicTime tx_deadline, Monoton
             const int select_res = driver_.select(masks, blocking_deadline);
             if (select_res < 0)
             {
-                return select_res;
+                return -ErrDriver;
             }
             assert(masks.read == 0);
         }
@@ -383,7 +383,7 @@ int CanIOManager::receive(CanRxFrame& out_frame, MonotonicTime blocking_deadline
             const int select_res = driver_.select(masks, blocking_deadline);
             if (select_res < 0)
             {
-                return select_res;
+                return -ErrDriver;
             }
         }
 
@@ -418,7 +418,7 @@ int CanIOManager::receive(CanRxFrame& out_frame, MonotonicTime blocking_deadline
                 {
                     counters_[i].frames_rx += 1;
                 }
-                return res;
+                return (res < 0) ? -ErrDriver : res;
             }
         }
 

libuavcan/src/transport/dispatcher.cpp

@@ -226,7 +226,7 @@ int Dispatcher::send(const Frame& frame, MonotonicTime tx_deadline, MonotonicTim
     if (frame.getSrcNodeID() != getNodeID())
     {
         assert(0);
-        return -1;
+        return -ErrLogic;
     }
 
     CanFrame can_frame;
@@ -234,7 +234,7 @@ int Dispatcher::send(const Frame& frame, MonotonicTime tx_deadline, MonotonicTim
     {
         UAVCAN_TRACE("Dispatcher", "Unable to send: frame is malformed: %s", frame.toString().c_str());
         assert(0);
-        return -1;
+        return -ErrLogic;
     }
     return canio_.send(can_frame, tx_deadline, blocking_deadline, iface_mask, qos, flags);
 }

libuavcan/src/transport/frame.cpp

@@ -29,7 +29,7 @@ int Frame::getMaxPayloadLen() const
     }
     default:
         assert(0);
-        return -1;
+        return -ErrLogic;
     }
 }
 

libuavcan/src/transport/transfer_buffer.cpp

@@ -113,7 +113,7 @@ int DynamicTransferBufferManagerEntry::read(unsigned int offset, uint8_t* data,
     if (!data)
     {
         assert(0);
-        return -1;
+        return -ErrInvalidParam;
     }
     if (offset >= max_write_pos_)
     {
@@ -148,7 +148,7 @@ int DynamicTransferBufferManagerEntry::write(unsigned int offset, const uint8_t*
     if (!data)
     {
         assert(0);
-        return -1;
+        return -ErrInvalidParam;
     }
 
     if (offset >= max_size_)
@@ -190,7 +190,6 @@ int DynamicTransferBufferManagerEntry::write(unsigned int offset, const uint8_t*
         if (new_block == NULL)
         {
             break;                        // We're in deep shit.
-
         }
         // Appending the chain with the new block
         if (last_written_block != NULL)

libuavcan/src/transport/transfer_listener.cpp

@@ -15,7 +15,7 @@ namespace uavcan
 int IncomingTransfer::write(unsigned int, const uint8_t*, unsigned int)
 {
     assert(0);  // Incoming transfer container is read-only
-    return -1;
+    return -ErrLogic;
 }
 
 /*
@@ -35,7 +35,7 @@ int SingleFrameIncomingTransfer::read(unsigned int offset, uint8_t* data, unsign
     if (data == NULL)
     {
         assert(0);
-        return -1;
+        return -ErrInvalidParam;
     }
     if (offset >= payload_len_)
     {
@@ -69,7 +69,7 @@ int MultiFrameIncomingTransfer::read(unsigned int offset, uint8_t* data, unsigne
     if (tbb == NULL)
     {
         UAVCAN_TRACE("MultiFrameIncomingTransfer", "Read failed: no such buffer");
-        return -1;
+        return -ErrLogic;
     }
     return tbb->read(offset, data, len);
 }

libuavcan/src/transport/transfer_sender.cpp

@@ -31,7 +31,7 @@ int TransferSender::send(const uint8_t* payload, int payload_len, MonotonicTime
             assert(0);
             UAVCAN_TRACE("TransferSender", "Frame payload write failure, %i", res);
             registerError();
-            return (res < 0) ? res : -1;
+            return (res < 0) ? res : -ErrLogic;
         }
         frame.makeLast();
         assert(frame.isLast() && frame.isFirst());
@@ -97,7 +97,7 @@ int TransferSender::send(const uint8_t* payload, int payload_len, MonotonicTime
     }
 
     assert(0);
-    return -1; // Return path analysis is apparently broken. There should be no warning, this 'return' is unreachable.
+    return -ErrLogic; // Return path analysis is apparently broken. There should be no warning, this 'return' is unreachable.
 }
 
 int TransferSender::send(const uint8_t* payload, int payload_len, MonotonicTime tx_deadline,
@@ -113,7 +113,7 @@ int TransferSender::send(const uint8_t* payload, int payload_len, MonotonicTime
     {
         UAVCAN_TRACE("TransferSender", "OTR access failure, dtd=%s tt=%i",
                      data_type_.toString().c_str(), int(transfer_type));
-        return -1;
+        return -ErrMemory;
     }
 
     const TransferID this_tid = tid->get();