cmd/gc: don't unpack struct arguments to append

Fixes #9634.

Change-Id: I7b18f26c2fb812978fc7adc5bfd39ebfffe48701
Reviewed-on: https://go-review.googlesource.com/3080
Reviewed-by: Minux Ma <minux@golang.org>

diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index 8a3b486bd6686013229c3a0acb9ab570ee5ba662..1abdb83c588f4bb6c34e2be38558726c14da0536 100644 (file)
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -1346,7 +1346,7 @@ reswitch:
                        goto error;
 
                // Unpack multiple-return result before type-checking.
-               if(istype(t, TSTRUCT)) {
+               if(istype(t, TSTRUCT) && t->funarg) {
                        t = t->type;
                        if(istype(t, TFIELD))
                                t = t->type;

diff --git a/test/fixedbugs/issue9634.go b/test/fixedbugs/issue9634.go
new file mode 100644 (file)
index 0000000..2d5aae4
--- /dev/null
+++ b/test/fixedbugs/issue9634.go
@@ -0,0 +1,18 @@
+// errorcheck
+
+// Copyright 2015 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.
+
+// Issue 9634: Structs are incorrectly unpacked when passed as an argument
+// to append.
+
+package main
+
+func main() {
+       s := struct{
+               t []int
+               u int
+       }{}
+       _ = append(s, 0) // ERROR "must be a slice|must be slice"
+}