rewrite &Point{1, 2} as allocation

R=ken
OCL=17592
CL=17592

src/cmd/gc/go.y

@@ -754,8 +754,6 @@ uexpr:
 	}
 |	'&' uexpr
 	{
-		if($2->op == OCONV && !func)
-			yyerror("& of composite literal at top level");
 		$$ = nod(OADDR, $2, N);
 	}
 |	'+' uexpr
@@ -1186,13 +1184,11 @@ xfndcl:
 	{
 		maxarg = 0;
 		stksize = 0;
-		func++;
 	} fndcl fnbody
 	{
 		$$ = $3;
 		$$->nbody = $4;
 		funcbody($$);
-		func--;
 	}
 
 fndcl:

src/cmd/gc/walk.c

@@ -895,6 +895,36 @@ loop:
 	case OADDR:
 		if(top != Erv)
 			goto nottop;
+		if(n->left->op == OCONV && iscomposite(n->left->type)) {
+			// turn &Point{1, 2} into allocation.
+			// initialize with
+			//	nvar := new(Point);
+			//	*nvar = Point{1, 2};
+			// and replace expression with nvar
+
+			// TODO(rsc): might do a better job (fewer copies) later
+			Node *nnew, *nvar, *nas;
+
+			walktype(n->left, Elv);
+			if(n->left == N)
+				goto ret;
+
+			nvar = nod(0, N, N);
+			tempname(nvar, ptrto(n->left->type));
+
+			nnew = nod(ONEW, N, N);
+			nnew->type = nvar->type;
+			nnew = newcompat(nnew);
+			
+			nas = nod(OAS, nvar, nnew);
+			addtop = list(addtop, nas);
+			
+			nas = nod(OAS, nod(OIND, nvar, N), n->left);
+			addtop = list(addtop, nas);
+
+			indir(n, nvar);
+			goto ret;
+		}
 		walktype(n->left, Elv);
 		if(n->left == N)
 			goto ret;

test/addr.go

@@ -1,9 +0,0 @@
-// errchk $G $D/$F.go
-
-// Copyright 2009 The Go Authors.  All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package main
-
-var a = &[]int{1,2};	// ERROR "composite"

test/complit.go

@@ -22,6 +22,11 @@ func eq(a *[]*R) {
 	}
 }
 
+type P struct { a, b int };
+func NewP(a, b int) *P {
+	return &P{a, b}
+}
+
 func main() {
 	var t T;
 	t = T{0, 7.2, "hi", &t};
@@ -57,4 +62,8 @@ func main() {
 	if len(m) != 3 { panic("m") }
 
 	eq(&[]*R{itor(0), itor(1), itor(2), itor(3), itor(4), itor(5)});
+	
+	p1 := NewP(1, 2);
+	p2 := NewP(1, 2);
+	if p1 == p2 { panic("NewP") }
 }

test/golden.out

@@ -129,11 +129,6 @@ found 2, expected 1
 panic on line 74 PC=xxx
 BUG wrong result
 
-=========== bugs/bug097.go
-
-panic on line 76 PC=xxx
-BUG wrong result
-
 =========== bugs/bug098.go
 bugs/bug098.go:10: illegal types for operand: AS
 	*M