cmd/compile: properly handle map assignments for OAS2DOTTYPE

The boolean destination in an OAS2DOTTYPE expression craps out during
compilation when trying to assign to a map entry because, unlike slice entries,
map entries are not directly addressable in memory. The solution is to
properly order the boolean destination node so that map entries are set
via autotmp variables.

Fixes #14678

Change-Id: If344e8f232b5bdac1b53c0f0d21eeb43ab17d3de
Reviewed-on: https://go-review.googlesource.com/22833
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/cmd/compile/internal/gc/order.go b/src/cmd/compile/internal/gc/order.go
index 7026ad79efa383caf6b33a102c7ef6a21ff7b5dd..d432b43460b88fdb2ea6a10a8e6254214679589d 100644 (file)
--- a/src/cmd/compile/internal/gc/order.go
+++ b/src/cmd/compile/internal/gc/order.go
@@ -569,18 +569,24 @@ func orderstmt(n *Node, order *Order) {
 
                orderexprlist(n.List, order)
                n.Rlist.First().Left = orderexpr(n.Rlist.First().Left, order, nil) // i in i.(T)
-               if isblank(n.List.First()) {
-                       order.out = append(order.out, n)
-               } else {
-                       typ := n.Rlist.First().Type
-                       tmp1 := ordertemp(typ, order, haspointers(typ))
-                       order.out = append(order.out, n)
-                       r := Nod(OAS, n.List.First(), tmp1)
-                       r = typecheck(r, Etop)
-                       ordermapassign(r, order)
-                       n.List.Set([]*Node{tmp1, n.List.Second()})
+
+               results := n.List.Slice()
+               var assigns [2]*Node
+
+               for r, res := range results {
+                       if !isblank(res) {
+                               results[r] = ordertemp(res.Type, order, haspointers(res.Type))
+                               assigns[r] = Nod(OAS, res, results[r])
+                       }
                }
+               order.out = append(order.out, n)
 
+               for _, assign := range assigns {
+                       if assign != nil {
+                               assign = typecheck(assign, Etop)
+                               ordermapassign(assign, order)
+                       }
+               }
                cleantemp(t, order)
 
                // Special: use temporary variables to hold result,

diff --git a/test/fixedbugs/issue14678.go b/test/fixedbugs/issue14678.go
new file mode 100644 (file)
index 0000000..94ca86d
--- /dev/null
+++ b/test/fixedbugs/issue14678.go
@@ -0,0 +1,27 @@
+// run
+
+// Copyright 2016 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
+
+func main() {
+       m := make(map[int]bool)
+       i := interface{}(1)
+       var v int
+
+       // Ensure map is updated properly
+       _, m[1] = i.(int)
+       v, m[2] = i.(int)
+
+       if v != 1 {
+               panic("fail: v should be 1")
+       }
+       if m[1] == false {
+               panic("fail: m[1] should be true")
+       }
+       if m[2] == false {
+               panic("fail: m[2] should be true")
+       }
+}