Allow named record constructors. Addresses #983.

src/Expr.cc

@@ -3320,12 +3320,20 @@ bool HasFieldExpr::DoUnserialize(UnserialInfo* info)
 	return UNSERIALIZE(&not_used) && UNSERIALIZE_STR(&field_name, 0) && UNSERIALIZE(&field);
 	}
 
-RecordConstructorExpr::RecordConstructorExpr(ListExpr* constructor_list)
+RecordConstructorExpr::RecordConstructorExpr(ListExpr* constructor_list,
+                                             BroType* arg_type)
 : UnaryExpr(EXPR_RECORD_CONSTRUCTOR, constructor_list)
 	{
 	if ( IsError() )
 		return;
 
+	if ( arg_type && arg_type->Tag() != TYPE_RECORD )
+		{
+		Error("bad record constructor type", arg_type);
+		SetError();
+		return;
+		}
+
 	// Spin through the list, which should be comprised of
 	// either record's or record-field-assign, and build up a
 	// record type to associate with this constructor.
@@ -3365,7 +3373,17 @@ RecordConstructorExpr::RecordConstructorExpr(ListExpr* constructor_list)
 			}
 		}
 
-	SetType(new RecordType(record_types));
+	ctor_type = new RecordType(record_types);
+
+	if ( arg_type )
+		SetType(arg_type->Ref());
+	else
+		SetType(ctor_type->Ref());
+	}
+
+RecordConstructorExpr::~RecordConstructorExpr()
+	{
+	Unref(ctor_type);
 	}
 
 Val* RecordConstructorExpr::InitVal(const BroType* t, Val* aggr) const
@@ -3391,7 +3409,7 @@ Val* RecordConstructorExpr::InitVal(const BroType* t, Val* aggr) const
 Val* RecordConstructorExpr::Fold(Val* v) const
 	{
 	ListVal* lv = v->AsListVal();
-	RecordType* rt = type->AsRecordType();
+	RecordType* rt = ctor_type->AsRecordType();
 
 	if ( lv->Length() != rt->NumFields() )
 		Internal("inconsistency evaluating record constructor");
@@ -3401,6 +3419,19 @@ Val* RecordConstructorExpr::Fold(Val* v) const
 	for ( int i = 0; i < lv->Length(); ++i )
 		rv->Assign(i, lv->Index(i)->Ref());
 
+	if ( ! same_type(rt, type) )
+		{
+		RecordVal* new_val = rv->CoerceTo(type->AsRecordType());
+
+		if ( new_val )
+			{
+			Unref(rv);
+			rv = new_val;
+			}
+		else
+			Internal("record constructor coercion failed");
+		}
+
 	return rv;
 	}
 
@@ -3416,12 +3447,16 @@ IMPLEMENT_SERIAL(RecordConstructorExpr, SER_RECORD_CONSTRUCTOR_EXPR);
 bool RecordConstructorExpr::DoSerialize(SerialInfo* info) const
 	{
 	DO_SERIALIZE(SER_RECORD_CONSTRUCTOR_EXPR, UnaryExpr);
+	SERIALIZE_OPTIONAL(ctor_type);
 	return true;
 	}
 
 bool RecordConstructorExpr::DoUnserialize(UnserialInfo* info)
 	{
 	DO_UNSERIALIZE(UnaryExpr);
+	BroType* t = 0;
+	UNSERIALIZE_OPTIONAL(t, RecordType::Unserialize(info));
+	ctor_type = t->AsRecordType();
 	return true;
 	}
 

src/Expr.h

@@ -57,6 +57,7 @@ extern const char* expr_name(BroExprTag t);
 class Stmt;
 class Frame;
 class ListExpr;
+class NameExpr;
 class CallExpr;
 class EventExpr;
 
@@ -165,6 +166,17 @@ public:
 		return (ListExpr*) this;
 		}
 
+	const NameExpr* AsNameExpr() const
+		{
+		CHECK_TAG(tag, EXPR_NAME, "ExprVal::AsNameExpr", expr_name)
+		return (const NameExpr*) this;
+		}
+	NameExpr* AsNameExpr()
+		{
+		CHECK_TAG(tag, EXPR_NAME, "ExprVal::AsNameExpr", expr_name)
+		return (NameExpr*) this;
+		}
+
 	void Describe(ODesc* d) const;
 
 	bool Serialize(SerialInfo* info) const;
@@ -729,7 +741,8 @@ protected:
 
 class RecordConstructorExpr : public UnaryExpr {
 public:
-	RecordConstructorExpr(ListExpr* constructor_list);
+	RecordConstructorExpr(ListExpr* constructor_list, BroType* arg_type = 0);
+	~RecordConstructorExpr();
 
 protected:
 	friend class Expr;
@@ -741,6 +754,8 @@ protected:
 	void ExprDescribe(ODesc* d) const;
 
 	DECLARE_SERIAL(RecordConstructorExpr);
+
+	RecordType* ctor_type; // type inferred from the ctor expression list args
 };
 
 class TableConstructorExpr : public UnaryExpr {

src/Type.h

@@ -217,6 +217,11 @@ public:
 		return tag == TYPE_TABLE && (YieldType() == 0);
 		}
 
+	int IsTable() const
+		{
+		return tag == TYPE_TABLE && (YieldType() != 0);
+		}
+
 	BroType* Ref()		{ ::Ref(this); return this; }
 
 	virtual void Describe(ODesc* d) const;

src/parse.y

@@ -522,10 +522,39 @@ expr:
 			$$ = new VectorConstructorExpr($3);
 			}
 
-	|	expr '(' opt_expr_list ')'
+	|	expr '('
 			{
-			set_location(@1, @4);
-			$$ = new CallExpr($1, $3, in_hook > 0);
+			if ( $1->Tag() == EXPR_NAME && $1->Type()->IsTable() )
+				++in_init;
+			}
+		opt_expr_list
+			{
+			if ( $1->Tag() == EXPR_NAME && $1->Type()->IsTable() )
+				--in_init;
+			}
+		')'
+			{
+			set_location(@1, @6);
+
+			BroType* ctor_type = 0;
+
+			if ( $1->Tag() == EXPR_NAME &&
+			     (ctor_type = $1->AsNameExpr()->Id()->AsType()) )
+				{
+				switch ( ctor_type->Tag() ) {
+				case TYPE_RECORD:
+					$$ = new RecordConstructorExpr($4, ctor_type);
+					break;
+				case TYPE_TABLE:
+				case TYPE_VECTOR:
+				default:
+					$1->Error("constructor type not implemented");
+					YYERROR;
+				}
+				}
+
+			else
+				$$ = new CallExpr($1, $4, in_hook > 0);
 			}
 
 	|	TOK_HOOK { ++in_hook; } expr

testing/btest/Baseline/language.named-ctors/out

@@ -0,0 +1,2 @@
+[min=<uninitialized>, max=2]
+[min=7, max=42]

testing/btest/language/named-ctors.bro

@@ -0,0 +1,12 @@
+# @TEST-EXEC: bro -b %INPUT >out
+# @TEST-EXEC: btest-diff out
+
+type MyRec: record {
+	min: count &optional;
+	max: count;
+};
+
+local myrec: MyRec = MyRec($max=2);
+print myrec;
+myrec = MyRec($min=7, $max=42);
+print myrec;