Reporter: Add dedicated Deprecation() method

Minimally, provide a way to funnel all deprecations through
reporter->Deprecation() instead of various Warning() invocations.

src/Reporter.cc

@@ -59,6 +59,8 @@ Reporter::Reporter(bool arg_abort_on_scripting_errors)
 	weird_sampling_duration = 0;
 	weird_sampling_threshold = 0;
 
+	ignore_deprecations = false;
+
 	syslog_open = false;
 	}
 
@@ -532,6 +534,21 @@ void Reporter::Weird(const IPAddr& orig, const IPAddr& resp, const char* name, c
 	            "%s", name);
 	}
 
+void Reporter::Deprecation(std::string_view msg, const detail::Location* loc1,
+                           const detail::Location* loc2)
+	{
+	if ( ignore_deprecations )
+		return;
+
+	if ( loc1 || loc2 )
+		PushLocation(loc1, loc2);
+
+	Warning("%s", msg.data());
+
+	if ( loc1 || loc2 )
+		PopLocation();
+	}
+
 void Reporter::DoLog(const char* prefix, EventHandlerPtr event, FILE* out, Connection* conn,
                      ValPList* addl, bool location, bool time, const char* postfix, const char* fmt,
                      va_list ap)

src/Reporter.h

@@ -133,6 +133,13 @@ public:
 	void Weird(const IPAddr& orig, const IPAddr& resp, const char* name, const char* addl = "",
 	           const char* source = ""); // Raises flow_weird().
 
+	// Report a deprecation. The message should contain a version.
+	void Deprecation(std::string_view msg, const detail::Location* loc1 = nullptr,
+	                 const detail::Location* loc2 = nullptr);
+
+	// Whether or not deprecations are logged when calling Deprecation()
+	void SetIgnoreDeprecations(bool arg) { ignore_deprecations = arg; }
+
 	// Syslog a message. This methods does nothing if we're running
 	// offline from a trace.
 	void Syslog(const char* fmt, ...) FMT_ATTR;
@@ -345,6 +352,8 @@ private:
 	uint64_t weird_sampling_threshold;
 	uint64_t weird_sampling_rate;
 	double weird_sampling_duration;
+
+	bool ignore_deprecations;
 	};
 
 extern Reporter* reporter;