Account static methods as source of expressions that produce mutable …

…values Summary: As in title Reviewed By: jamesjwu Differential Revision: D7326427 fbshipit-source-id: f23ab59ae59aa3fae3d93121305eafe836bc9195
facebook · Mar 20, 2018 · 42fd0c9 · 42fd0c9
1 parent 82a61ab
commit 42fd0c9
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Showing 3 changed files with 24 additions and 1 deletion.
diff --git a/hphp/hack/src/typing/typing_mutability.ml b/hphp/hack/src/typing/typing_mutability.ml
@@ -31,7 +31,8 @@ let rec expr_returns_owned_mutable
  | T.Call (_, (_, T.Id id), _, _, _)
  | T.Call (_, (_, T.Fun_id id), _, _, _) ->
    fun_returns_mutable env id
- | T.Call (_, ((_, (Some (_, Tfun fty))), T.Obj_get _), _, _, _) ->
+ | T.Call (_, ((_, (Some (_, Tfun fty))), T.Obj_get _), _, _, _)
+ | T.Call (_, ((_, (Some (_, Tfun fty))), T.Class_const _), _, _, _)->
    fty.ft_returns_mutable
  (* conditional operator returns owned mutable if both consequence and alternative
     return owned mutable *)

diff --git a/hphp/hack/test/typecheck/reactive/mutable_return1.php b/hphp/hack/test/typecheck/reactive/mutable_return1.php
@@ -0,0 +1,21 @@
+<?hh // strict
+
+class A {
+  <<__Rx, __Mutable>>
+  public function __construct(private int $x) {
+  }
+  <<__Rx, __MutableReturn>>
+  public static function get(): A {
+    return new A(1);
+  }
+  <<__Rx, __Mutable>>
+  public function setX(int $newX): void {
+    $this->x = $newX;
+  }
+}
+
+<<__Rx>>
+function f(): void {
+  $a = A::get();
+  $a->setX(5);
+}
diff --git a/hphp/hack/test/typecheck/reactive/mutable_return1.php.exp b/hphp/hack/test/typecheck/reactive/mutable_return1.php.exp
@@ -0,0 +1 @@
+No errors