Add templated As() method to Val, use in various places we were using dynamic_cast

src/Expr.cc

@@ -1853,7 +1853,7 @@ ValPtr EqExpr::Fold(Val* v1, Val* v2) const
 	{
 	if ( op1->GetType()->Tag() == TYPE_PATTERN )
 		{
-		auto re = dynamic_cast<PatternVal*>(v1);
+		auto re = v1->As<PatternVal*>();
 		const String* s = v2->AsString();
 		if ( tag == EXPR_EQ )
 			return val_mgr->Bool(re->MatchExactly(s));
@@ -4151,7 +4151,7 @@ ValPtr InExpr::Fold(Val* v1, Val* v2) const
 	{
 	if ( v1->GetType()->Tag() == TYPE_PATTERN )
 		{
-		auto re = dynamic_cast<PatternVal*>(v1);
+		auto re = v1->As<PatternVal*>();
 		const String* s = v2->AsString();
 		return val_mgr->Bool(re->MatchAnywhere(s) != 0);
 		}

src/ID.cc

@@ -87,7 +87,7 @@ FuncPtr id::find_func(std::string_view name)
 		reporter->InternalError("Expected variable '%s' to be a function",
 		                              std::string(name).data());
 
-	return dynamic_cast<FuncVal*>(v.get())->AsFuncPtr();
+	return v.get()->As<FuncVal*>()->AsFuncPtr();
 	}
 
 void id::detail::init_types()
@@ -162,7 +162,7 @@ void ID::SetVal(ValPtr v)
 	     type->AsFuncType()->Flavor() == FUNC_FLAVOR_EVENT )
 		{
 		EventHandler* handler = event_registry->Lookup(name);
-		auto func = dynamic_cast<FuncVal*>(val.get())->AsFuncPtr();
+		auto func = val.get()->As<FuncVal*>()->AsFuncPtr();
 		if ( ! handler )
 			{
 			handler = new EventHandler(name);

src/Sessions.cc

@@ -318,7 +318,7 @@ Connection* NetSessions::FindConnection(Val* v)
 		return nullptr;
 
 	RecordType* vr = vt->AsRecordType();
-	auto vl = dynamic_cast<RecordVal*>(v);
+	auto vl = v->As<RecordVal*>();
 
 	int orig_h, orig_p;	// indices into record's value list
 	int resp_h, resp_p;

src/Val.h

@@ -12,6 +12,7 @@
 #include "zeek/Type.h"
 #include "zeek/Timer.h"
 #include "zeek/Notifier.h"
+#include "zeek/Reporter.h"
 #include "zeek/net_util.h"
 
 // We have four different port name spaces: TCP, UDP, ICMP, and UNKNOWN.
@@ -209,6 +210,19 @@ UNDERLYING_ACCESSOR_DECL(TypeVal, zeek::Type*, AsType)
 
 	StringValPtr ToJSON(bool only_loggable=false, RE_Matcher* re=nullptr);
 
+	template<typename T>
+	T As()
+		{
+		// Since we're converting from "this", make sure the type requested is a pointer.
+		static_assert(std::is_pointer<T>());
+
+		auto v = dynamic_cast<T>(this);
+		if ( ! v )
+			reporter->InternalError("Failed dynamic_cast between Val types");
+
+		return v;
+		}
+
 protected:
 
 	// Friends with access to Clone().

src/option.bif

@@ -209,7 +209,7 @@ function Option::set_change_handler%(ID: string, on_change: any, priority: int &
 		return zeek::val_mgr->False();
 		}
 
-	auto func = dynamic_cast<FuncVal*>(on_change)->AsFuncPtr();
+	auto func = on_change->As<FuncVal*>()->AsFuncPtr();
 	i->AddOptionHandler(func, -priority);
 	return zeek::val_mgr->True();
 	%}

src/strings.bif

@@ -707,7 +707,7 @@ function str_smith_waterman%(s1: string, s2: string, params: sw_params%) : sw_su
 ## .. zeek:see:: split_string split_string1 split_string_all split_string_n
 function str_split%(s: string, idx: index_vec%): string_vec &deprecated="Remove in v4.1. Use str_split_indices."
 	%{
-	auto idx_v = dynamic_cast<VectorVal*>(idx);
+	auto idx_v = idx->As<VectorVal*>();
 	auto n = idx_v->Size();
 	zeek::String::IdxVec indices(n);
 	unsigned int i;
@@ -746,7 +746,7 @@ function str_split%(s: string, idx: index_vec%): string_vec &deprecated="Remove
 ## .. zeek:see:: split_string split_string1 split_string_all split_string_n
 function str_split_indices%(s: string, idx: index_vec%): string_vec
 	%{
-	auto idx_v = dynamic_cast<VectorVal*>(idx);
+	auto idx_v = idx->As<VectorVal*>();
 	auto n = idx_v->Size();
 	zeek::String::IdxVec indices(n);
 	unsigned int i;

src/zeek.bif

@@ -1432,7 +1432,7 @@ function sort%(v: any, ...%) : any
 	if ( ! comp && ! IsIntegral(elt_type->Tag()) )
 		zeek::emit_builtin_error("comparison function required for sort() with non-integral types");
 
-	auto vv = dynamic_cast<VectorVal*>(v);
+	auto vv = v->As<zeek::VectorVal*>();
 
 	if ( comp )
 		{
@@ -1502,7 +1502,7 @@ function order%(v: any, ...%) : index_vec
 	if ( ! comp && ! IsIntegral(elt_type->Tag()) )
 		zeek::emit_builtin_error("comparison function required for order() with non-integral types");
 
-	auto vv = dynamic_cast<VectorVal*>(v);
+	auto vv = v->As<zeek::VectorVal*>();
 	auto n = vv->Size();
 
 	// Set up initial mapping of indices directly to corresponding
@@ -2410,7 +2410,7 @@ function addr_to_counts%(a: addr%): index_vec
 ## .. zeek:see:: addr_to_counts
 function counts_to_addr%(v: index_vec%): addr
 	%{
-	auto vv = dynamic_cast<VectorVal*>(v);
+	auto vv = v->As<zeek::VectorVal*>();
 
 	if ( vv->Size() == 1 )
 		{
@@ -3528,8 +3528,8 @@ function lookup_connection%(cid: conn_id%): connection
 %%{
 const char* conn_id_string(zeek::Val* c)
 	{
-	auto id = dynamic_cast<const zeek::RecordVal*>(c)->GetField(0);
+	auto id = c->As<zeek::RecordVal*>()->GetField(0);
-	auto id_r = dynamic_cast<const zeek::RecordVal*>(id.get());
+	auto id_r = id->As<zeek::RecordVal*>();
 
 	const zeek::IPAddr& orig_h = id_r->GetAddrField(0);
 	uint32_t orig_p = id_r->GetPortValField(1)->Port();
@@ -3654,7 +3654,7 @@ function dump_packet%(pkt: pcap_packet, file_name: string%) : bool
 		uint32_t caplen, len, link_type;
 		u_char *data;
 
-		auto pkt_r = dynamic_cast<RecordVal*>(pkt);
+		auto pkt_r = pkt->As<zeek::RecordVal*>();
 
 		ts.tv_sec = pkt_r->GetCountField(0);
 		ts.tv_usec = pkt_r->GetCountField(1);