Mark one-parameter constructors as explicit & use override where possible

This commit marks (hopefully) ever one-parameter constructor as explicit.

It also uses override in (hopefully) all circumstances where a virtual
method is overridden.

There are a very few other minor changes - most of them were necessary
to get everything to compile (like one additional constructor). In one
case I changed an implicit operation to an explicit string conversion -
I think the automatically chosen conversion was much more convoluted.

This took longer than I want to admit but not as long as I feared :)

src/file_analysis/AnalyzerSet.h

@@ -29,7 +29,7 @@ public:
 	 * Constructor.  Nothing special.
 	 * @param arg_file the file to which all analyzers in the set are attached.
 	 */
-	AnalyzerSet(File* arg_file);
+	explicit AnalyzerSet(File* arg_file);
 
 	/**
 	 * Destructor.  Any queued analyzer additions/removals are aborted and
@@ -173,9 +173,9 @@ private:
 		 */
 		AddMod(file_analysis::Analyzer* arg_a, HashKey* arg_key)
 			: Modification(), a(arg_a), key(arg_key) {}
-		virtual ~AddMod() {}
-		virtual bool Perform(AnalyzerSet* set);
-		virtual void Abort() { delete a; delete key; }
+		~AddMod() override {}
+		bool Perform(AnalyzerSet* set) override;
+		void Abort() override { delete a; delete key; }
 
 	protected:
 		file_analysis::Analyzer* a;
@@ -194,9 +194,9 @@ private:
 		 */
 		RemoveMod(file_analysis::Tag arg_tag, HashKey* arg_key)
 			: Modification(), tag(arg_tag), key(arg_key) {}
-		virtual ~RemoveMod() {}
-		virtual bool Perform(AnalyzerSet* set);
-		virtual void Abort() { delete key; }
+		~RemoveMod() override {}
+		bool Perform(AnalyzerSet* set) override;
+		void Abort() override { delete key; }
 
 	protected:
 		file_analysis::Tag tag;

src/file_analysis/Component.h

@@ -52,7 +52,7 @@ public:
 	/**
 	 * Destructor.
 	 */
-	~Component();
+	~Component() override;
 
 	/**
 	 * Initialization function. This function has to be called before any

src/file_analysis/FileReassembler.h

@@ -15,7 +15,7 @@ class FileReassembler : public Reassembler {
 public:
 
 	FileReassembler(File* f, uint64 starting_offset);
-	virtual ~FileReassembler();
+	~FileReassembler() override;
 
 	void Done();
 

src/file_analysis/FileTimer.h

@@ -28,7 +28,7 @@ public:
 	 * @param t current unix time
 	 * @param is_expire true if all pending timers are being expired.
 	 */
-	void Dispatch(double t, int is_expire);
+	void Dispatch(double t, int is_expire) override;
 
 private:
 	string file_id;

src/file_analysis/Tag.h

@@ -97,14 +97,14 @@ protected:
 	 * @param subtype The sub type, which is left to an analyzer for
 	 * interpretation. By default it's set to zero.
 	 */
-	Tag(type_t type, subtype_t subtype = 0);
+	explicit Tag(type_t type, subtype_t subtype = 0);
 
 	/**
 	 * Constructor.
 	 *
 	 * @param val An enum value of script type \c Files::Tag.
 	 */
-	Tag(EnumVal* val) : ::Tag(val) {}
+	explicit Tag(EnumVal* val) : ::Tag(val) {}
 };
 
 }

src/file_analysis/analyzer/data_event/DataEvent.h

@@ -25,7 +25,7 @@ public:
 	 * @param offset number of bytes from start of file at which chunk occurs.
 	 * @return always true
 	 */
-	virtual bool DeliverChunk(const u_char* data, uint64 len, uint64 offset);
+	bool DeliverChunk(const u_char* data, uint64 len, uint64 offset) override;
 
 	/**
 	 * Generates the event, if any, specified by the "stream_event" field of
@@ -34,7 +34,7 @@ public:
 	 * @param len number of bytes in the data chunk.
 	 * @return always true
 	 */
-	virtual bool DeliverStream(const u_char* data, uint64 len);
+	bool DeliverStream(const u_char* data, uint64 len) override;
 
 	/**
 	 * Create a new instance of a DataEvent analyzer.

src/file_analysis/analyzer/entropy/Entropy.h

@@ -23,7 +23,7 @@ public:
 	/**
 	 * Destructor.
 	 */
-	virtual ~Entropy();
+	~Entropy() override;
 
 	/**
 	 * Create a new instance of an Extract analyzer.
@@ -40,13 +40,13 @@ public:
 	 * @param len number of bytes in the data chunk.
 	 * @return false if the digest is in an invalid state, else true.
 	 */
-	virtual bool DeliverStream(const u_char* data, uint64 len);
+	bool DeliverStream(const u_char* data, uint64 len) override;
 
 	/**
 	 * Finalizes the hash and raises a "file_entropy_test" event.
 	 * @return always false so analyze will be deteched from file.
 	 */
-	virtual bool EndOfFile();
+	bool EndOfFile() override;
 
 	/**
 	 * Missing data can't be handled, so just indicate the this analyzer should
@@ -55,7 +55,7 @@ public:
 	 * @param len number of missing bytes.
 	 * @return always false so analyzer will detach from file.
 	 */
-	virtual bool Undelivered(uint64 offset, uint64 len);
+	bool Undelivered(uint64 offset, uint64 len) override;
 
 protected:
 

src/file_analysis/analyzer/extract/Extract.h

@@ -22,7 +22,7 @@ public:
 	/**
 	 * Destructor.  Will close the file that was used for data extraction.
 	 */
-	virtual ~Extract();
+	~Extract() override;
 
 	/**
 	 * Write a chunk of file data to the local extraction file.
@@ -31,7 +31,7 @@ public:
 	 * @return false if there was no extraction file open and the data couldn't
 	 *         be written, else true.
 	 */
-	virtual bool DeliverStream(const u_char* data, uint64 len);
+	bool DeliverStream(const u_char* data, uint64 len) override;
 
 	/**
 	 * Report undelivered bytes.
@@ -39,7 +39,7 @@ public:
 	 * @param len number of bytes undelivered.
 	 * @return true
 	 */
-	virtual bool Undelivered(uint64 offset, uint64 len);
+	bool Undelivered(uint64 offset, uint64 len) override;
 
 	/**
 	 * Create a new instance of an Extract analyzer.

src/file_analysis/analyzer/hash/Hash.h

@@ -23,7 +23,7 @@ public:
 	/**
 	 * Destructor.
 	 */
-	virtual ~Hash();
+	~Hash() override;
 
 	/**
 	 * Incrementally hash next chunk of file contents.
@@ -31,13 +31,13 @@ public:
 	 * @param len number of bytes in the data chunk.
 	 * @return false if the digest is in an invalid state, else true.
 	 */
-	virtual bool DeliverStream(const u_char* data, uint64 len);
+	bool DeliverStream(const u_char* data, uint64 len) override;
 
 	/**
 	 * Finalizes the hash and raises a "file_hash" event.
 	 * @return always false so analyze will be deteched from file.
 	 */
-	virtual bool EndOfFile();
+	bool EndOfFile() override;
 
 	/**
 	 * Missing data can't be handled, so just indicate the this analyzer should
@@ -46,7 +46,7 @@ public:
 	 * @param len number of missing bytes.
 	 * @return always false so analyzer will detach from file.
 	 */
-	virtual bool Undelivered(uint64 offset, uint64 len);
+	bool Undelivered(uint64 offset, uint64 len) override;
 
 protected:
 

src/file_analysis/analyzer/unified2/Unified2.h

@@ -17,9 +17,9 @@ namespace file_analysis {
  */
 class Unified2 : public file_analysis::Analyzer {
 public:
-	virtual ~Unified2();
+	~Unified2() override;
 
-	virtual bool DeliverStream(const u_char* data, uint64 len);
+	bool DeliverStream(const u_char* data, uint64 len) override;
 
 	static file_analysis::Analyzer* Instantiate(RecordVal* args, File* file);
 

src/file_analysis/analyzer/x509/OCSP.h

@@ -40,7 +40,7 @@ private:
 class OCSP_RESPVal: public OpaqueVal {
 public:
 	explicit OCSP_RESPVal(OCSP_RESPONSE *);
-	~OCSP_RESPVal();
+	~OCSP_RESPVal() override;
 	OCSP_RESPONSE *GetResp() const;
 protected:
 	OCSP_RESPVal();

src/file_analysis/analyzer/x509/X509.h

@@ -121,7 +121,7 @@ public:
 	/**
 	 * Destructor.
 	 */
-	~X509Val();
+	~X509Val() override;
 
 	/**
 	 * Get the wrapped X509 certificate. Please take care, that the

src/file_analysis/analyzer/x509/X509Common.h

@@ -16,7 +16,7 @@ namespace file_analysis {
 
 class X509Common : public file_analysis::Analyzer {
 public:
-	virtual ~X509Common() {};
+	~X509Common() override {};
 
 	/**
 	 * Retrieve an X509 extension value from an OpenSSL BIO to which it was