const/var/iota declarations as discussed

R=r
OCL=20506
CL=20506

src/cmd/gc/dcl.c

@@ -1212,3 +1212,86 @@ embedded(Sym *s)
 		yyerror("embedded type cannot be a pointer");
 	return n;
 }
+
+/*
+ * declare variables from grammar
+ * new_name_list [type] = expr_list
+ */
+Node*
+variter(Node *vv, Type *t, Node *ee)
+{
+	Iter viter, eiter;
+	Node *v, *e, *r, *a;
+
+	vv = rev(vv);
+	ee = rev(ee);
+
+	v = listfirst(&viter, &vv);
+	e = listfirst(&eiter, &ee);
+	r = N;
+
+loop:
+	if(v == N && e == N)
+		return rev(r);
+	
+	if(v == N || e == N) {
+		yyerror("shape error in var dcl");
+		return rev(r);
+	}
+
+	a = nod(OAS, v, N);
+	if(t == T) {
+		gettype(e, a);
+		defaultlit(e);
+		dodclvar(v, e->type);
+	} else
+		dodclvar(v, t);
+	a->right = e;
+
+	r = list(r, a);
+
+	v = listnext(&viter);
+	e = listnext(&eiter);
+	goto loop;
+}
+
+/*
+ * declare constants from grammar
+ * new_name_list [type] [= expr_list]
+ */
+void
+constiter(Node *vv, Type *t, Node *cc)
+{
+	Iter viter, citer;
+	Node *v, *c, *a;
+
+	if(cc == N)
+		cc = lastconst;
+	lastconst = cc;
+	vv = rev(vv);
+	cc = rev(treecopy(cc));
+
+	v = listfirst(&viter, &vv);
+	c = listfirst(&citer, &cc);
+
+loop:
+	if(v == N && c == N) {
+		iota += 1;
+		return;
+	}
+	
+	if(v == N || c == N) {
+		yyerror("shape error in var dcl");
+		iota += 1;
+		return;
+	}
+
+	gettype(c, N);
+	if(t != T)
+		convlit(c, t);
+	dodclconst(v, c);
+
+	v = listnext(&viter);
+	c = listnext(&citer);
+	goto loop;
+}

src/cmd/gc/go.h

@@ -713,6 +713,8 @@ void	checkwidth(Type*);
 void	defercheckwidth(void);
 void	resumecheckwidth(void);
 Node*	embedded(Sym*);
+Node*	variter(Node*, Type*, Node*);
+void	constiter(Node*, Type*, Node*);
 
 /*
  *	export.c

src/cmd/gc/go.y

@@ -318,60 +318,37 @@ Bvardcl:
 		if(addtop != N)
 			fatal("new_name_list_r type '=' expr_list");
 
-		$$ = rev($1);
-		dodclvar($$, $2);
-
-		$$ = nod(OAS, $$, $4);
+		$$ = variter($1, $2, $4);
 		addtotop($$);
 	}
-|	new_name '=' expr
+|	new_name_list_r '=' expr_list
 	{
-		$$ = nod(OAS, $1, N);
-		gettype($3, $$);
-		defaultlit($3);
-		dodclvar($1, $3->type);
-		$$->right = $3;
+		if(addtop != N)
+			fatal("new_name_list_r '=' expr_list");
+
+		$$ = variter($1, T, $3);
+		addtotop($$);
 	}
 
 constdcl:
-	new_name type '=' expr
+	new_name_list_r type '=' expr_list
 	{
-		Node *c = treecopy($4);
-		gettype(c, N);
-		convlit(c, $2);
-		dodclconst($1, c);
-
-		lastconst = $4;
-		iota += 1;
+		constiter($1, $2, $4);
 	}
-|	new_name '=' expr
+|	new_name_list_r '=' expr_list
 	{
-		Node *c = treecopy($3);
-		gettype(c, N);
-		dodclconst($1, c);
-
-		lastconst = $3;
-		iota += 1;
+		constiter($1, T, $3);
 	}
 
 constdcl1:
 	constdcl
-|	new_name type
+|	new_name_list_r type
 	{
-		Node *c = treecopy(lastconst);
-		gettype(c, N);
-		convlit(c, $2);
-		dodclconst($1, c);
-
-		iota += 1;
+		constiter($1, $2, N);
 	}
-|	new_name
+|	new_name_list_r
 	{
-		Node *c = treecopy(lastconst);
-		gettype(c, N);
-		dodclconst($1, c);
-
-		iota += 1;
+		constiter($1, T, N);
 	}
 
 typedclname: