gc: check for assignment to private fields during initialization

R=ken2
https://golang.org/cl/165055

diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index 76147e48f025dc07eee3471755a0713186cc6e1e..a92b684ae4c777c1c5478eb2c70633177e2f434a 100644 (file)
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -1961,8 +1961,12 @@ typecheckas(Node *n)
 
        checkassign(n->left);
        typecheck(&n->right, Erv);
-       if(n->left->type != T && n->right && n->right->type != T)
-               n->right = typecheckconv(nil, n->right, n->left->type, 0, nil);
+       if(n->right && n->right->type != T) {
+               if(n->left->type != T)
+                       n->right = typecheckconv(nil, n->right, n->left->type, 0, "assignment");
+               else
+                       exportassignok(n->right->type, "assignment");
+       }
        if(n->left->defn == n && n->left->ntype == N) {
                defaultlit(&n->right, T);
                n->left->type = n->right->type;

diff --git a/test/assign.go b/test/assign.go
index 842bd62d4d0a28c51e8239a2204410acee4318e7..fea7c282853e30ea7ca669338d63663f715fbd8c 100644 (file)
--- a/test/assign.go
+++ b/test/assign.go
@@ -42,4 +42,12 @@ func main() {
                x := sync.Mutex{key: 0};        // ERROR "(unknown|assignment).*Mutex"
                _ = x;
        }
+       {
+               x := &sync.Mutex{};     // ok
+               var y sync.Mutex;       // ok
+               y = *x; // ERROR "assignment.*Mutex"
+               *x = y; // ERROR "assignment.*Mutex"
+               _ = x;
+               _ = y;
+       }               
 }

diff --git a/test/fixedbugs/bug226.dir/x.go b/test/fixedbugs/bug226.dir/x.go
new file mode 100644 (file)
index 0000000..64d7a29
--- /dev/null
+++ b/test/fixedbugs/bug226.dir/x.go
@@ -0,0 +1,9 @@
+// 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 x
+
+type T struct { x, Y int }
+
+func (t T) M()

diff --git a/test/fixedbugs/bug226.dir/y.go b/test/fixedbugs/bug226.dir/y.go
new file mode 100644 (file)
index 0000000..01e8b7b
--- /dev/null
+++ b/test/fixedbugs/bug226.dir/y.go
@@ -0,0 +1,31 @@
+// 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 y
+
+import "./x"
+
+func f() {
+       ok := new(x.T);
+       var ok1 x.T;
+       ok2 := &ok1;
+       ok3 := &x.T{};
+       ok4 := &x.T{Y:2};
+       _ = x.T{};
+       _ = x.T{Y:2};
+       
+       ok1.M();        // ERROR "assignment.*T"
+       bad1 := *ok;    // ERROR "assignment.*T"
+       bad2 := ok1;    // ERROR "assignment.*T"
+       *ok4 = ok1;     // ERROR "assignment.*T"
+       *ok4 = *ok2;    // ERROR "assignment.*T"
+       ok1 = *ok4;     // ERROR "assignment.*T"
+       _ = bad1;
+       _ = bad2;
+       _ = ok4;
+       _ = ok3;
+       _ = ok2;
+       _ = ok1;
+       _ = ok;
+}

diff --git a/test/fixedbugs/bug226.go b/test/fixedbugs/bug226.go
new file mode 100644 (file)
index 0000000..5457a64
--- /dev/null
+++ b/test/fixedbugs/bug226.go
@@ -0,0 +1,7 @@
+// $G $D/$F.dir/x.go && errchk $G $D/$F.dir/y.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.
+
+ignored