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 7fb669fd48f1026f07d035d975d0bc443096f2cc..bf732ba65cd31ff1aae50a996c1dc7898d1a41d6 100644 (file)
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7442,7 +7442,7 @@ 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 dc9145892c488ed9382d56b1eaa8afd1b06bc70b..8e60b94739794d68b454d0b9aaf586a4bb06f835 100644 (file)
--- a/gcc/cp/init.c
+++ b/gcc/cp/init.c
@@ -878,7 +878,7 @@ 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);
       release_tree_vector (cleanups);
     }
   else if (type_build_ctor_call (type)

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 596dc4d6447f0b4a890e3d204aa1d35dfac7498b..579bfcbdc5c1c1ff49c84414cddadc501a5ee4a5 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();
+}