gc: ... changes

R=ken2, ken3
CC=golang-dev
https://golang.org/cl/2208047

src/cmd/gc/go.y

@@ -68,7 +68,7 @@ static void fixlbrace(int);
 
 %type	<list>	xdcl fnbody fnres switch_body loop_body dcl_name_list
 %type	<list>	new_name_list expr_list keyval_list braced_keyval_list expr_or_type_list xdcl_list
-%type	<list>	oexpr_list oexpr_or_type_list_ocomma caseblock_list stmt_list oarg_type_list_ocomma arg_type_list
+%type	<list>	oexpr_list caseblock_list stmt_list oarg_type_list_ocomma arg_type_list
 %type	<list>	interfacedcl_list vardcl vardcl_list structdcl structdcl_list
 %type	<list>	common_dcl constdcl constdcl1 constdcl_list typedcl_list
 
@@ -808,11 +808,21 @@ uexpr:
  * can be preceded by 'defer' and 'go'
  */
 pseudocall:
-	pexpr '(' oexpr_or_type_list_ocomma ')'
+	pexpr '(' ')'
+	{
+		$$ = nod(OCALL, $1, N);
+	}
+|	pexpr '(' expr_or_type_list ocomma ')'
 	{
 		$$ = nod(OCALL, $1, N);
 		$$->list = $3;
 	}
+|	pexpr '(' expr_or_type_list LDDD ocomma ')'
+	{
+		$$ = nod(OCALL, $1, N);
+		$$->list = $3;
+		$$->isddd = 1;
+	}
 
 pexpr_no_paren:
 	LLITERAL
@@ -1583,12 +1593,6 @@ oexpr_list:
 	}
 |	expr_list
 
-oexpr_or_type_list_ocomma:
-	{
-		$$ = nil;
-	}
-|	expr_or_type_list ocomma
-
 osimple_stmt:
 	{
 		$$ = N;

src/cmd/gc/subr.c

@@ -271,7 +271,6 @@ setlineno(Node *n)
 	case OTYPE:
 	case OPACK:
 	case OLITERAL:
-	case ONONAME:
 		break;
 	default:
 		lineno = n->lineno;
@@ -3033,11 +3032,14 @@ genwrapper(Type *rcvr, Type *method, Sym *newnam, int iface)
 	Node *this, *fn, *call, *n, *t, *pad;
 	NodeList *l, *args, *in, *out;
 	Type *tpad;
+	int isddd;
 
 	if(debug['r'])
 		print("genwrapper rcvrtype=%T method=%T newnam=%S\n",
 			rcvr, method, newnam);
 
+	lineno = 1;	// less confusing than end of input
+
 	dclcontext = PEXTERN;
 	markdcl();
 
@@ -3069,12 +3071,16 @@ genwrapper(Type *rcvr, Type *method, Sym *newnam, int iface)
 
 	// arg list
 	args = nil;
-	for(l=in; l; l=l->next)
+	isddd = 0;
+	for(l=in; l; l=l->next) {
 		args = list(args, l->n->left);
+		isddd = l->n->left->isddd;
+	}
 
 	// generate call
 	call = nod(OCALL, adddot(nod(OXDOT, this->left, newname(method->sym))), N);
 	call->list = args;
+	call->isddd = isddd;
 	fn->nbody = list1(call);
 	if(method->type->outtuple > 0) {
 		n = nod(ORETURN, N, N);

src/cmd/gc/typecheck.c

@@ -17,7 +17,7 @@ static void	implicitstar(Node**);
 static int	onearg(Node*, char*, ...);
 static int	twoarg(Node*);
 static int	lookdot(Node*, Type*, int);
-static void	typecheckaste(int, Type*, NodeList*, char*);
+static void	typecheckaste(int, int, Type*, NodeList*, char*);
 static Type*	lookdot1(Sym *s, Type *t, Type *f, int);
 static int	nokeys(NodeList*);
 static void	typecheckcomplit(Node**);
@@ -716,12 +716,16 @@ reswitch:
 	case OCALL:
 		l = n->left;
 		if(l->op == ONAME && (r = unsafenmagic(n)) != N) {
+			if(n->isddd)
+				yyerror("invalid use of ... with builtin %#N", l);
 			n = r;
 			goto reswitch;
 		}
 		typecheck(&n->left, Erv | Etype | Ecall);
 		l = n->left;
 		if(l->op == ONAME && l->etype != 0) {
+			if(n->isddd)
+				yyerror("invalid use of ... with builtin %#N", l);
 			// builtin: OLEN, OCAP, etc.
 			n->op = l->etype;
 			n->left = n->right;
@@ -731,6 +735,8 @@ reswitch:
 		defaultlit(&n->left, T);
 		l = n->left;
 		if(l->op == OTYPE) {
+			if(n->isddd)
+				yyerror("invalid use of ... in type conversion", l);
 			// pick off before type-checking arguments
 			ok |= Erv;
 			// turn CALL(type, arg) into CONV(arg) w/ type
@@ -757,7 +763,7 @@ reswitch:
 
 		case ODOTMETH:
 			n->op = OCALLMETH;
-			typecheckaste(OCALL, getthisx(t), list1(l->left), "method receiver");
+			typecheckaste(OCALL, 0, getthisx(t), list1(l->left), "method receiver");
 			break;
 
 		default:
@@ -768,7 +774,7 @@ reswitch:
 			}
 			break;
 		}
-		typecheckaste(OCALL, getinargx(t), n->list, "function argument");
+		typecheckaste(OCALL, n->isddd, getinargx(t), n->list, "function argument");
 		ok |= Etop;
 		if(t->outtuple == 0)
 			goto ret;
@@ -1160,7 +1166,7 @@ reswitch:
 		}
 		if(curfn->type->outnamed && n->list == nil)
 			goto ret;
-		typecheckaste(ORETURN, getoutargx(curfn->type), n->list, "return argument");
+		typecheckaste(ORETURN, 0, getoutargx(curfn->type), n->list, "return argument");
 		goto ret;
 
 	case OSELECT:
@@ -1451,7 +1457,7 @@ nokeys(NodeList *l)
  * typecheck assignment: type list = expression list
  */
 static void
-typecheckaste(int op, Type *tstruct, NodeList *nl, char *desc)
+typecheckaste(int op, int isddd, Type *tstruct, NodeList *nl, char *desc)
 {
 	Type *t, *tl, *tn;
 	Node *n;
@@ -1465,7 +1471,6 @@ typecheckaste(int op, Type *tstruct, NodeList *nl, char *desc)
 
 	if(nl != nil && nl->next == nil && (n = nl->n)->type != T)
 	if(n->type->etype == TSTRUCT && n->type->funarg) {
-		setlineno(n);
 		tn = n->type->type;
 		for(tl=tstruct->type; tl; tl=tl->down) {
 			if(tl->isddd) {
@@ -1474,29 +1479,34 @@ typecheckaste(int op, Type *tstruct, NodeList *nl, char *desc)
 						yyerror("cannot use %T as type %T in %s%s", tn->type, tl->type->type, desc, why);
 				goto out;
 			}
-			if(tn == T) {
+			if(tn == T)
-				yyerror("not enough arguments to %#O", op);
+				goto notenough;
-				goto out;
-			}
 			if(assignop(tn->type, tl->type, &why) == 0)
 				yyerror("cannot use %T as type %T in %s%s", tn->type, tl->type, desc, why);
 			tn = tn->down;
 		}
 		if(tn != T)
-			yyerror("too many arguments to %#O", op);
+			goto toomany;
 		goto out;
 	}
 
 	for(tl=tstruct->type; tl; tl=tl->down) {
 		t = tl->type;
 		if(tl->isddd) {
-			if(nl != nil && nl->n->isddd && !eqtype(nl->n->type, t)) {
+			if(nl != nil && nl->n->isddd && !isddd) {
-				// TODO(rsc): This is not actually illegal but will
+				// TODO(rsc): This is not actually illegal, but it will help catch bugs.
-				// help catch bugs.
+				yyerror("to pass '%#N' as ...%T, use '%#N...'", nl->n, t->type, nl->n);
-				yyerror("cannot pass %+N as %T (... mismatch)", nl->n, tl);
+				isddd = 1;
 			}
-			if(nl != nil && nl->next == nil && nl->n->isddd && eqtype(nl->n->type, t))
+			if(isddd) {
+				if(nl == nil)
+					goto notenough;
+				if(nl->next != nil)
+					goto toomany;
+				if(assignop(nl->n->type, t, &why) == 0)
+					yyerror("ddd cannot use %+N as type %T in %s%s", nl->n, t, desc, why);
 				goto out;
+			}
 			for(; nl; nl=nl->next) {
 				setlineno(nl->n);
 				defaultlit(&nl->n, t->type);
@@ -1505,23 +1515,30 @@ typecheckaste(int op, Type *tstruct, NodeList *nl, char *desc)
 			}
 			goto out;
 		}
-		if(nl == nil) {
+		if(nl == nil)
-			yyerror("not enough arguments to %#O", op);
+			goto notenough;
-			goto out;
-		}
 		n = nl->n;
-		setlineno(nl->n);
+		setlineno(n);
 		if(n->type != T)
 			nl->n = assignconv(n, t, desc);
 		nl = nl->next;
 	}
-	if(nl != nil) {
+	if(nl != nil)
-		yyerror("too many arguments to %#O", op);
+		goto toomany;
-		goto out;
+	if(isddd)
-	}
+		yyerror("invalid use of ... in %#O", op);
 
 out:
 	lineno = lno;
+	return;
+
+notenough:
+	yyerror("not enough arguments to %#O", op);
+	goto out;
+
+toomany:
+	yyerror("too many arguments to %#O", op);
+	goto out;
 }
 
 /*
@@ -1695,11 +1712,13 @@ typecheckcomplit(Node **np)
 	NodeList *ll;
 	Type *t, *f;
 	Sym *s;
+	int32 lno;
 
 	n = *np;
+	lno = lineno;
 
 	memset(hash, 0, sizeof hash);
-
+	setlineno(n->right);
 	l = typecheck(&n->right /* sic */, Etype);
 	if((t = l->type) == T)
 		goto error;
@@ -1715,6 +1734,7 @@ typecheckcomplit(Node **np)
 		i = 0;
 		for(ll=n->list; ll; ll=ll->next) {
 			l = ll->n;
+			setlineno(l);
 			if(l->op == OKEY) {
 				typecheck(&l->left, Erv);
 				evconst(l->left);
@@ -1756,6 +1776,7 @@ typecheckcomplit(Node **np)
 	case TMAP:
 		for(ll=n->list; ll; ll=ll->next) {
 			l = ll->n;
+			setlineno(l);
 			if(l->op != OKEY) {
 				typecheck(&ll->n, Erv);
 				yyerror("missing key in map literal");
@@ -1778,6 +1799,7 @@ typecheckcomplit(Node **np)
 			// simple list of variables
 			f = t->type;
 			for(ll=n->list; ll; ll=ll->next) {
+				setlineno(ll->n);
 				typecheck(&ll->n, Erv);
 				if(f == nil) {
 					if(!bad++)
@@ -1798,6 +1820,7 @@ typecheckcomplit(Node **np)
 			// keyed list
 			for(ll=n->list; ll; ll=ll->next) {
 				l = ll->n;
+				setlineno(l);
 				if(l->op != OKEY) {
 					if(!bad++)
 						yyerror("mixture of field:value and value initializers");
@@ -1836,11 +1859,13 @@ typecheckcomplit(Node **np)
 	n->type = t;
 
 	*np = n;
+	lineno = lno;
 	return;
 
 error:
 	n->type = T;
 	*np = n;
+	lineno = lno;
 }
 
 /*

test/ddd1.go

@@ -6,6 +6,8 @@
 
 package main
 
+import "unsafe"
+
 func sum(args ...int) int { return 0 }
 
 var (
@@ -26,3 +28,20 @@ var (
 	_ = funny(nil, nil)
 	_ = funny([]T{}) // ok because []T{} is a T; passes []T{[]T{}}
 )
+
+func bad(args ...int) {
+	print(1, 2, args...)	// ERROR "[.][.][.]"
+	println(args...)	// ERROR "[.][.][.]"
+	ch := make(chan int)
+	close(ch...)	// ERROR "[.][.][.]"
+	_ = len(args...)	// ERROR "[.][.][.]"
+	_ = closed(ch...)	// ERROR "[.][.][.]"
+	_ = new(int...)	// ERROR "[.][.][.]"
+	n := 10
+	_ = make([]byte, n...)	// ERROR "[.][.][.]"
+	// TODO(rsc): enable after gofmt bug is fixed
+	//	_ = make([]byte, 10 ...)	// error "[.][.][.]"
+	var x int
+	_ = unsafe.Pointer(&x...)	// ERROR "[.][.][.]"
+	_ = unsafe.Sizeof(x...)	// ERROR "[.][.][.]"
+}