commit a7dc31796b5a7aab2818fa9cb7e0f345ecc8fdf0
Author: Jason Merrill <jason@redhat.com>
Date: Tue Jul 9 02:51:34 2013 -0400
PR c++/57437
* typeck.c (check_return_expr): Lambda proxies aren't eligible
for nrv or return by move.
@@ -8399,7 +8399,8 @@ check_return_expr (tree retval, bool *no_warning)
&& VAR_P (retval)
&& DECL_CONTEXT (retval) == current_function_decl
&& ! TREE_STATIC (retval)
- && ! DECL_ANON_UNION_VAR_P (retval)
+ /* And not a lambda or anonymous union proxy. */
+ && !DECL_HAS_VALUE_EXPR_P (retval)
&& (DECL_ALIGN (retval) <= DECL_ALIGN (result))
/* The cv-unqualified type of the returned value must be the
same as the cv-unqualified return type of the
@@ -8444,7 +8445,7 @@ check_return_expr (tree retval, bool *no_warning)
Note that these conditions are similar to, but not as strict as,
the conditions for the named return value optimization. */
if ((cxx_dialect != cxx98)
- && (VAR_P (retval)
+ && ((VAR_P (retval) && !DECL_HAS_VALUE_EXPR_P (retval))
|| TREE_CODE (retval) == PARM_DECL)
&& DECL_CONTEXT (retval) == current_function_decl
&& !TREE_STATIC (retval)
new file mode 100644
@@ -0,0 +1,26 @@
+// PR c++/57437
+// { dg-require-effective-target c++11 }
+
+struct A {
+ int i;
+
+ A(): i(42) {}
+ A(const A&) = default;
+ A(A&& a): i(a.i) { a.i = 0; }
+};
+
+int main()
+{
+ A x;
+
+ auto y = [x] () mutable {
+ x.i++;
+ return x;
+ };
+
+ if (y().i != 43)
+ __builtin_abort ();
+
+ if (y().i != 44)
+ __builtin_abort ();
+}