C++: Fix shared pointer handling for PacketPayload base class.

bindings/cxx/classes.cpp

@@ -973,6 +973,9 @@ Packet::Packet(shared_ptr<Device> device,
 				static_cast<const struct sr_datafeed_analog *>(
 					structure->payload));
 			break;
+		default:
+			payload = nullptr;
+			break;
 	}
 }
 
@@ -989,7 +992,10 @@ const PacketType *Packet::get_type()
 
 shared_ptr<PacketPayload> Packet::get_payload()
 {
-	return payload->get_shared_pointer(this);
+	if (payload)
+		return payload->get_shared_pointer(this);
+	else
+		throw Error(SR_ERR_NA);
 }
 
 PacketPayload::PacketPayload()
@@ -1001,8 +1007,8 @@ PacketPayload::~PacketPayload()
 }
 
 Header::Header(const struct sr_datafeed_header *structure) :
-	PacketPayload(),
+	StructureWrapper<Packet, const struct sr_datafeed_header>(structure),
-	StructureWrapper<Packet, const struct sr_datafeed_header>(structure)
+	PacketPayload()
 {
 }
 
@@ -1010,6 +1016,14 @@ Header::~Header()
 {
 }
 
+shared_ptr<PacketPayload> Header::get_shared_pointer(Packet *parent)
+{
+	return static_pointer_cast<PacketPayload>(
+		static_pointer_cast<Header>(
+		StructureWrapper<Packet, const struct sr_datafeed_header>::
+			get_shared_pointer(parent)));
+}
+
 int Header::get_feed_version()
 {
 	return structure->feed_version;
@@ -1023,8 +1037,8 @@ Glib::TimeVal Header::get_start_time()
 }
 
 Meta::Meta(const struct sr_datafeed_meta *structure) :
-	PacketPayload(),
+	StructureWrapper<Packet, const struct sr_datafeed_meta>(structure),
-	StructureWrapper<Packet, const struct sr_datafeed_meta>(structure)
+	PacketPayload()
 {
 }
 
@@ -1032,6 +1046,14 @@ Meta::~Meta()
 {
 }
 
+shared_ptr<PacketPayload> Meta::get_shared_pointer(Packet *parent)
+{
+	return static_pointer_cast<PacketPayload>(
+		static_pointer_cast<Meta>(
+		StructureWrapper<Packet, const struct sr_datafeed_meta>::
+			get_shared_pointer(parent)));
+}
+
 map<const ConfigKey *, Glib::VariantBase> Meta::get_config()
 {
 	map<const ConfigKey *, Glib::VariantBase> result;
@@ -1044,8 +1066,8 @@ map<const ConfigKey *, Glib::VariantBase> Meta::get_config()
 }
 
 Logic::Logic(const struct sr_datafeed_logic *structure) :
-	PacketPayload(),
+	StructureWrapper<Packet, const struct sr_datafeed_logic>(structure),
-	StructureWrapper<Packet, const struct sr_datafeed_logic>(structure)
+	PacketPayload()
 {
 }
 
@@ -1053,6 +1075,14 @@ Logic::~Logic()
 {
 }
 
+shared_ptr<PacketPayload> Logic::get_shared_pointer(Packet *parent)
+{
+	return static_pointer_cast<PacketPayload>(
+		static_pointer_cast<Logic>(
+		StructureWrapper<Packet, const struct sr_datafeed_logic>::
+			get_shared_pointer(parent)));
+}
+
 void *Logic::get_data_pointer()
 {
 	return structure->data;
@@ -1069,8 +1099,8 @@ unsigned int Logic::get_unit_size()
 }
 
 Analog::Analog(const struct sr_datafeed_analog *structure) :
-	PacketPayload(),
+	StructureWrapper<Packet, const struct sr_datafeed_analog>(structure),
-	StructureWrapper<Packet, const struct sr_datafeed_analog>(structure)
+	PacketPayload()
 {
 }
 
@@ -1078,6 +1108,14 @@ Analog::~Analog()
 {
 }
 
+shared_ptr<PacketPayload> Analog::get_shared_pointer(Packet *parent)
+{
+	return static_pointer_cast<PacketPayload>(
+		static_pointer_cast<Analog>(
+		StructureWrapper<Packet, const struct sr_datafeed_analog>::
+			get_shared_pointer(parent)));
+}
+
 float *Analog::get_data_pointer()
 {
 	return structure->data;

bindings/cxx/include/libsigrok/libsigrok.hpp

@@ -645,9 +645,7 @@ class SR_API PacketPayload
 protected:
 	PacketPayload();
 	virtual ~PacketPayload() = 0;
-	shared_ptr<PacketPayload> get_shared_pointer(Packet *parent) {
+	virtual shared_ptr<PacketPayload> get_shared_pointer(Packet *parent) = 0;
-		return static_pointer_cast<PacketPayload>(get_shared_pointer(parent));
-	}
 	/** Deleter needed to allow shared_ptr use with protected destructor. */
 	class Deleter
 	{
@@ -660,8 +658,9 @@ protected:
 };
 
 /** Payload of a datafeed header packet */
-class SR_API Header : public PacketPayload,
+class SR_API Header :
-	public StructureWrapper<Packet, const struct sr_datafeed_header>
+	public StructureWrapper<Packet, const struct sr_datafeed_header>,
+	public PacketPayload
 {
 public:
 	/* Feed version number. */
@@ -671,13 +670,14 @@ public:
 protected:
 	Header(const struct sr_datafeed_header *structure);
 	~Header();
-	const struct sr_datafeed_header *structure;
+	shared_ptr<PacketPayload> get_shared_pointer(Packet *parent);
 	friend class Packet;
 };
 
 /** Payload of a datafeed metadata packet */
-class SR_API Meta : public PacketPayload,
+class SR_API Meta :
-	public StructureWrapper<Packet, const struct sr_datafeed_meta>
+	public StructureWrapper<Packet, const struct sr_datafeed_meta>,
+	public PacketPayload
 {
 public:
 	/* Mapping of (ConfigKey, value) pairs. */
@@ -685,14 +685,15 @@ public:
 protected:
 	Meta(const struct sr_datafeed_meta *structure);
 	~Meta();
-	const struct sr_datafeed_meta *structure;
+	shared_ptr<PacketPayload> get_shared_pointer(Packet *parent);
 	map<const ConfigKey *, Glib::VariantBase> config;
 	friend class Packet;
 };
 
 /** Payload of a datafeed packet with logic data */
-class SR_API Logic : public PacketPayload,
+class SR_API Logic :
-	public StructureWrapper<Packet, const struct sr_datafeed_logic>
+	public StructureWrapper<Packet, const struct sr_datafeed_logic>,
+	public PacketPayload
 {
 public:
 	/* Pointer to data. */
@@ -704,13 +705,14 @@ public:
 protected:
 	Logic(const struct sr_datafeed_logic *structure);
 	~Logic();
-	const struct sr_datafeed_logic *structure;
+	shared_ptr<PacketPayload> get_shared_pointer(Packet *parent);
 	friend class Packet;
 };
 
 /** Payload of a datafeed packet with analog data */
-class SR_API Analog : public PacketPayload,
+class SR_API Analog :
-	public StructureWrapper<Packet, const struct sr_datafeed_analog>
+	public StructureWrapper<Packet, const struct sr_datafeed_analog>,
+	public PacketPayload
 {
 public:
 	/** Pointer to data. */
@@ -728,7 +730,7 @@ public:
 protected:
 	Analog(const struct sr_datafeed_analog *structure);
 	~Analog();
-	const struct sr_datafeed_analog *structure;
+	shared_ptr<PacketPayload> get_shared_pointer(Packet *parent);
 	friend class Packet;
 };