re PR c++/57437 (C++11: mutable lambdas)

	PR c++/57437
	* typeck.c (check_return_expr): Lambda proxies aren't eligible
	for nrv or return by move.

From-SVN: r200832

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index a9abf59eb7075067786ed01d04c67b9affa6047c..b0e6133b9f78ebca24ec35bf9f2b898f78845a94 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2013-07-09  Jason Merrill  <jason@redhat.com>
 
+       PR c++/57437
+       * typeck.c (check_return_expr): Lambda proxies aren't eligible
+       for nrv or return by move.
+
        PR c++/57545
        * pt.c (convert_nontype_argument) [INTEGER_CST]: Force the
        argument to have the exact type of the parameter.

diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index c404c81c5e3c0f0e28781bd38234b5f473e41697..796eea6465cbabfd3228d2a071cd0e044055a0c7 100644 (file)
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -7929,7 +7929,8 @@ check_return_expr (tree retval, bool *no_warning)
      && TREE_CODE (retval) == VAR_DECL
      && 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 (DECL_RESULT (current_function_decl)))
      /* The cv-unqualified type of the returned value must be the
@@ -7978,7 +7979,8 @@ 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)
-          && (TREE_CODE (retval) == VAR_DECL
+          && ((TREE_CODE (retval) == VAR_DECL
+              && !DECL_HAS_VALUE_EXPR_P (retval))
              || TREE_CODE (retval) == PARM_DECL)
          && DECL_CONTEXT (retval) == current_function_decl
          && !TREE_STATIC (retval)

diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-return1.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-return1.C
new file mode 100644 (file)
index 0000000..4b353b6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-return1.C
@@ -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 ();
+}