PR c++/68949

	* optimize.c (maybe_clone_body): Clear DECL_SAVED_TREE of the alias.
	* semantics.c (expand_or_defer_fn_1): Keep DECL_SAVED_TREE of
	maybe-in-charge *tor.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-5-branch@232896 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 38 insertions, 3 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index d80724b3959..0c21b216569 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,10 @@
 2016-01-27  Jason Merrill  <jason@redhat.com>
 
+	PR c++/68949
+	* optimize.c (maybe_clone_body): Clear DECL_SAVED_TREE of the alias.
+	* semantics.c (expand_or_defer_fn_1): Keep DECL_SAVED_TREE of
+	maybe-in-charge *tor.
+
 	PR c++/69131
 	* method.c (walk_field_subobs): Add dtor_from_ctor parm.
 	(process_subob_fn): Likewise.  Don't consider triviality if true.
diff --git a/gcc/cp/optimize.c b/gcc/cp/optimize.c
index a2dd880ea49..e485a6da817 100644
--- a/gcc/cp/optimize.c
+++ b/gcc/cp/optimize.c
@@ -670,6 +670,8 @@ maybe_clone_body (tree fn)
 	{
 	  if (expand_or_defer_fn_1 (clone))
 	    emit_associated_thunks (clone);
+	  /* We didn't generate a body, so remove the empty one.  */
+	  DECL_SAVED_TREE (clone) = NULL_TREE;
 	}
       else
 	expand_or_defer_fn (clone);
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index feba03d1c7f..abd30e23ce8 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -4104,9 +4104,8 @@ expand_or_defer_fn_1 (tree fn)
       /* We don't want to process FN again, so pretend we've written
 	 it out, even though we haven't.  */
       TREE_ASM_WRITTEN (fn) = 1;
-      /* If this is an instantiation of a constexpr function, keep
-	 DECL_SAVED_TREE for explain_invalid_constexpr_fn.  */
-      if (!is_instantiation_of_constexpr (fn))
+      /* If this is a constexpr function, keep DECL_SAVED_TREE.  */
+      if (!DECL_DECLARED_CONSTEXPR_P (fn))
 	DECL_SAVED_TREE (fn) = NULL_TREE;
       return false;
     }
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-array15.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-array15.C
new file mode 100644
index 00000000000..a59e6f5df14
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-array15.C
@@ -0,0 +1,29 @@
+// PR c++/68949
+// { dg-do run { target c++11 } }
+
+struct Sub {
+    int i;
+
+    constexpr Sub() : i(-1) {} // remove constexpr and it works as expected
+    Sub(Sub&& rhs); // remove this constructor and it works as epxected.
+};
+
+// v-- move this inline and it works as expected
+// v-- remove ': Sub()' and it works as expected
+Sub::Sub(Sub&& rhs) : Sub() { int tmp = i; i = rhs.i; rhs.i = tmp; }
+
+struct Class {
+    // v-- remove '[1]' and it works as expected
+    // v-- add '= {}' and it works as expected
+    Sub s[1];
+
+    // v-- add ': s{}' and it works as expected
+    // v-- removing this constructor makes it work as expected
+    Class() {}
+};
+
+int main() {
+    Class c;
+    if (c.s[0].i != -1)
+      __builtin_abort();
+}