c++: fix ICE with xobj in destructor [PR113340]

Here we crash in maybe_retrofit_in_chrg on an invalid dtor
with explicit this.  Such member functions do not get converted
to METHOD_TYPE.  If a dtor gets parameters, we reset arg_types
to void_list_node in grokdeclarator.  This results in m_r_in_c
receiving:
  void <T8d> (void)
and crashing on
  parms = DECL_CHAIN (DECL_ARGUMENTS (fn));

This patch avoids the ICE by resetting is_xobj_member_function after
emitting the error.  Then m_r_in_c gets
  void S::<T40b> (struct S *)
which does not cause a crash.

	PR c++/113340

gcc/cp/ChangeLog:

	* decl.cc (grokdeclarator) <case cdk_function>: Clear
	is_xobj_member_function in case of an error.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp23/explicit-obj-diagnostics9.C: New test.

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index b10a72a87bf0a1cabab52c1e4b657bc8a379b91e..2e5702971c4c0b145722fcda71dfc72c6331994d 100644 (file)
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -13743,6 +13743,7 @@ grokdeclarator (const cp_declarator *declarator,
                          "destructors may not have parameters");
                arg_types = void_list_node;
                parms = NULL_TREE;
+               is_xobj_member_function = false;
              }
 
            type = build_function_type (type, arg_types);

diff --git a/gcc/testsuite/g++.dg/cpp23/explicit-obj-diagnostics9.C b/gcc/testsuite/g++.dg/cpp23/explicit-obj-diagnostics9.C
new file mode 100644 (file)
index 0000000..d420793
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp23/explicit-obj-diagnostics9.C
@@ -0,0 +1,6 @@
+// PR c++/113340
+// { dg-do compile { target c++23 } }
+
+struct S {
+  ~S(this S &) = default; // { dg-error "destructors may not have parameters" }
+};