c++: NRV and ref-extended temps [PR101442]

This issue goes back to r83221, where the cleanup for extended ref temps
changed from being unconditional to being tied to the declaration they
formed part of the initializer for.

The named return value optimization changes the cleanup for the NRV variable
to only run on the EH path; we don't want that change to affect temporary
cleanups.  The perform_member_init change isn't necessary (there 'decl' is a
COMPONENT_REF), it's just for consistency.

	PR c++/101442

gcc/cp/ChangeLog:

	* decl.c (cp_finish_decl): Don't pass decl to push_cleanup.
	* init.c (perform_member_init): Likewise.
	* semantics.c (push_cleanup): Adjust comment.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/initlist-nrv1.C: New test.

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 99a4eb59ba8d951e8c3d06325a605d4aa9c240fc..6089cd7e52df2bf35271e98b556a3ec7b440fd86 100644 (file)
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7993,7 +7993,7 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
     {
       unsigned i; tree t;
       FOR_EACH_VEC_ELT (*cleanups, i, t)
-       push_cleanup (decl, t, false);
+       push_cleanup (NULL_TREE, t, false);
       release_tree_vector (cleanups);
     }
 

diff --git a/gcc/cp/init.c b/gcc/cp/init.c
index 35c142be60fde76aac850d2f5092f88276d14cea..fb62bfe7294d8c977050c357b90ee5c1810ec3d7 100644 (file)
--- a/gcc/cp/init.c
+++ b/gcc/cp/init.c
@@ -888,7 +888,7 @@ perform_member_init (tree member, tree init)
       init = build2 (INIT_EXPR, type, decl, init);
       finish_expr_stmt (init);
       FOR_EACH_VEC_ELT (*cleanups, i, t)
-       push_cleanup (decl, t, false);
+       push_cleanup (NULL_TREE, t, false);
     }
   else if (type_build_ctor_call (type)
           || (init && CLASS_TYPE_P (strip_array_types (type))))

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 315f89115009a802db9a1a034472d043e7b11d42..d846a1bd8f0b185b01af1a2a5c67c336c34cd346 100644 (file)
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -476,7 +476,8 @@ do_pushlevel (scope_kind sk)
 
 /* Queue a cleanup.  CLEANUP is an expression/statement to be executed
    when the current scope is exited.  EH_ONLY is true when this is not
-   meant to apply to normal control flow transfer.  */
+   meant to apply to normal control flow transfer.  DECL is the VAR_DECL
+   being cleaned up, if any, or null for temporaries or subobjects.  */
 
 void
 push_cleanup (tree decl, tree cleanup, bool eh_only)

diff --git a/gcc/testsuite/g++.dg/cpp0x/initlist-nrv1.C b/gcc/testsuite/g++.dg/cpp0x/initlist-nrv1.C
new file mode 100644 (file)
index 0000000..e44dbec
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/initlist-nrv1.C
@@ -0,0 +1,34 @@
+// PR c++/101442
+// { dg-do run { target c++11 } }
+
+bool destroyed = false;
+
+struct A
+{
+  A() {}
+  A(const A &) = delete;
+  A &operator=(const A &) = delete;
+  ~A() {destroyed = true;}
+};
+
+struct B
+{
+  const A &a;
+  struct string {
+    string(const char*) { }
+    ~string() { }
+  } s;
+};
+
+B foo()
+{
+  B ret{ A{}, "" };
+  return ret;
+}
+
+int main()
+{
+  B b = foo();
+  if (!destroyed)
+    __builtin_abort();
+}