Meaningful error codes instead of plain -1

libuavcan/include/uavcan/node/generic_publisher.hpp

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <uavcan/error.hpp>
 #include <uavcan/node/abstract_node.hpp>
 #include <uavcan/data_type.hpp>
 #include <uavcan/node/global_data_type_registry.hpp>
@@ -35,11 +36,11 @@ class GenericPublisher
     INode& node_;
     LazyConstructor<TransferSender> sender_;
 
-    bool checkInit()
+    int checkInit()
     {
         if (sender_)
         {
-            return true;
+            return 0;
         }
 
         GlobalDataTypeRegistry::instance().freeze();
@@ -50,11 +51,11 @@ class GenericPublisher
         if (!descr)
         {
             UAVCAN_TRACE("GenericPublisher", "Type [%s] is not registered", DataSpec::getDataTypeFullName());
-            return false;
+            return -ErrUnknownDataType;
         }
         sender_.template construct<Dispatcher&, const DataTypeDescriptor&, CanTxQueue::Qos, MonotonicDuration>
             (node_.getDispatcher(), *descr, CanTxQueue::Qos(Qos), max_transfer_interval_);
-        return true;
+        return 0;
     }
 
     MonotonicTime getTxDeadline() const { return node_.getMonotonicTime() + tx_timeout_; }
@@ -67,15 +68,16 @@ class GenericPublisher
     int genericPublish(const DataStruct& message, TransferType transfer_type, NodeID dst_node_id,
                        TransferID* tid, MonotonicTime blocking_deadline)
     {
-        if (!checkInit())
+        const int res = checkInit();
+        if (res < 0)
         {
-            return -1;
+            return res;
         }
 
         IMarshalBuffer* const buf = getBuffer();
         if (!buf)
         {
-            return -1;
+            return -ErrMemory;
         }
 
         {
@@ -85,7 +87,7 @@ class GenericPublisher
             if (encode_res <= 0)
             {
                 assert(0);   // Impossible, internal error
-                return -1;
+                return -ErrInvalidMarshalData;
             }
         }
         if (tid)
@@ -117,7 +119,7 @@ public:
 
     int init()
     {
-        return checkInit() ? 0 : -1;
+        return checkInit();
     }
 
     int publish(const DataStruct& message, TransferType transfer_type, NodeID dst_node_id,
@@ -134,7 +136,7 @@ public:
 
     TransferSender* getTransferSender()
     {
-        checkInit();
+        (void)checkInit();
         return sender_.isConstructed() ? static_cast<TransferSender*>(sender_) : NULL;
     }
 

libuavcan/include/uavcan/node/generic_subscriber.hpp

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <uavcan/error.hpp>
 #include <uavcan/node/abstract_node.hpp>
 #include <uavcan/data_type.hpp>
 #include <uavcan/node/global_data_type_registry.hpp>
@@ -113,11 +114,11 @@ class GenericSubscriber : Noncopyable
     ReceivedDataStructureSpec message_;
     uint32_t failure_count_;
 
-    bool checkInit()
+    int checkInit()
     {
         if (forwarder_)
         {
-            return true;
+            return 0;
         }
 
         GlobalDataTypeRegistry::instance().freeze();
@@ -128,11 +129,11 @@ class GenericSubscriber : Noncopyable
         if (!descr)
         {
             UAVCAN_TRACE("GenericSubscriber", "Type [%s] is not registered", DataSpec::getDataTypeFullName());
-            return false;
+            return -ErrUnknownDataType;
         }
         forwarder_.template construct<SelfType&, const DataTypeDescriptor&, IAllocator&>
             (*this, *descr, node_.getAllocator());
-        return true;
+        return 0;
     }
 
     bool decodeTransfer(IncomingTransfer& transfer)
@@ -167,19 +168,20 @@ class GenericSubscriber : Noncopyable
     {
         stop();
 
-        if (!checkInit())
+        const int res = checkInit();
+        if (res < 0)
         {
             UAVCAN_TRACE("GenericSubscriber", "Initialization failure [%s]", DataSpec::getDataTypeFullName());
-            return -1;
+            return res;
         }
 
         if (!(node_.getDispatcher().*registration_method)(forwarder_))
         {
             UAVCAN_TRACE("GenericSubscriber", "Failed to register transfer listener [%s]",
                          DataSpec::getDataTypeFullName());
-            return -1;
+            return -ErrInvalidTransferListener;
         }
-        return 1;
+        return 0;
     }
 
 protected:

libuavcan/include/uavcan/node/node.hpp

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <cassert>
+#include <uavcan/error.hpp>
 #include <uavcan/impl_constants.hpp>
 #include <uavcan/dynamic_memory.hpp>
 #include <uavcan/node/abstract_node.hpp>
@@ -94,7 +95,7 @@ public:
         {
             return INode::spin(deadline);
         }
-        return -1;
+        return -ErrNotInited;
     }
 
     int spin(MonotonicDuration duration)
@@ -103,7 +104,7 @@ public:
         {
             return INode::spin(duration);
         }
-        return -1;
+        return -ErrNotInited;
     }
 
     bool isStarted() const { return started_; }

libuavcan/include/uavcan/node/publisher.hpp

@@ -37,7 +37,7 @@ public:
         if (!dst_node_id.isUnicast())
         {
             assert(0);
-            return -1;
+            return -ErrInvalidParam;
         }
         return publish(message, TransferTypeMessageUnicast, dst_node_id);
     }

libuavcan/include/uavcan/node/scheduler.hpp

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <uavcan/error.hpp>
 #include <uavcan/linked_list.hpp>
 #include <uavcan/transport/dispatcher.hpp>
 

libuavcan/include/uavcan/node/service_client.hpp

@@ -182,7 +182,7 @@ public:
         if (!isCallbackValid())
         {
             UAVCAN_TRACE("ServiceClient", "Invalid callback");
-            return -1;
+            return -ErrInvalidParam;
         }
         pending_ = true;
 
@@ -196,7 +196,7 @@ public:
         {
             UAVCAN_TRACE("ServiceClient", "Type [%s] is not registered", DataType::getDataTypeFullName());
             cancel();
-            return -1;
+            return -ErrUnknownDataType;
         }
 
         /*
@@ -211,7 +211,7 @@ public:
         {
             UAVCAN_TRACE("ServiceClient", "OTR access failure, dtd=%s", descr->toString().c_str());
             cancel();
-            return -1;
+            return -ErrMemory;
         }
         const TransferID transfer_id = *otr_tid;
         otr_tid->increment();
@@ -235,7 +235,7 @@ public:
         {
             assert(0);  // Must have been created
             cancel();
-            return -1;
+            return -ErrLogic;
         }
         const typename TransferListenerType::ExpectedResponseParams erp(server_node_id, transfer_id);
         tl->setExpectedResponseParams(erp);

libuavcan/include/uavcan/node/service_server.hpp

@@ -91,7 +91,7 @@ public:
         if (!try_implicit_cast<bool>(callback, true))
         {
             UAVCAN_TRACE("ServiceServer", "Invalid callback");
-            return -1;
+            return -ErrInvalidParam;
         }
         callback_ = callback;
 

libuavcan/include/uavcan/node/subscriber.hpp

@@ -67,7 +67,7 @@ public:
         if (!try_implicit_cast<bool>(callback, true))
         {
             UAVCAN_TRACE("Subscriber", "Invalid callback");
-            return -1;
+            return -ErrInvalidParam;
         }
         callback_ = callback;