diff mbox series

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

Message ID 20220414002346.3271123-1-jason@redhat.com
State Committed
Commit ad8161e6d7b26d690d90069ae9a129e7ac36892a
Headers
Series [pushed] c++: NRV and ref-extended temps [PR101442] |

Commit Message

Jason Merrill April 14, 2022, 12:23 a.m. UTC 
  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.

Tested x86_64-pc-linux-gnu, applying to trunk.

	PR c++/101442

gcc/cp/ChangeLog:

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

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/initlist-nrv1.C: New test.
---
 gcc/cp/decl.cc                             |  2 +-
 gcc/cp/init.cc                             |  2 +-
 gcc/cp/semantics.cc                        |  3 +-
 gcc/testsuite/g++.dg/cpp0x/initlist-nrv1.C | 34 ++++++++++++++++++++++
 4 files changed, 38 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/initlist-nrv1.C


base-commit: 019d6d4149ee97d55ce9efe4e5e470d38130cdeb
diff mbox series

Patch

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 5f59612fb00..d51fd75b003 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -8554,7 +8554,7 @@  cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
     {
       for (tree t : *cleanups)
 	{
-	  push_cleanup (decl, t, false);
+	  push_cleanup (NULL_TREE, t, false);
 	  /* As in initialize_local_var.  */
 	  wrap_temporary_cleanups (init, t);
 	}
diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
index 7ce8d3a46e5..75ab965a218 100644
--- a/gcc/cp/init.cc
+++ b/gcc/cp/init.cc
@@ -1066,7 +1066,7 @@  perform_member_init (tree member, tree init, hash_set<tree> &uninitialized)
       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.cc b/gcc/cp/semantics.cc
index 43627ed30af..f5ec808b1bc 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -666,7 +666,8 @@  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
index 00000000000..e44dbecfece
--- /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();
+}