From: Nathaniel Shead <nathanieloshead@gmail.com>
Date: Thu, 8 May 2025 13:06:13 +0000 (+1000)
Subject: c++/modules: Fix handling of -fdeclone-ctor-dtor with explicit instantiations [PR120125]
X-Git-Tag: releases/gcc-14.3.0~24
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b1a99c3e2cf0fb858ad42b19c6834f7593f091d;p=thirdparty%2Fgcc.git

c++/modules: Fix handling of -fdeclone-ctor-dtor with explicit instantiations [PR120125]

The attached testcase ICEs in maybe_thunk_body because we haven't
created a node in the cgraph for an imported explicit instantiation yet.

We in fact really shouldn't be emitting calls at all, since an imported
explicit instantiation always exists in the TU we imported it from.  But
the required logic for that doesn't exist in this branch, so we'll just
xfail the relevant check.

	PR c++/120125

gcc/cp/ChangeLog:

	* optimize.cc (maybe_thunk_body): Don't assume 'fn' has a cgraph
	node created.

gcc/testsuite/ChangeLog:

	* g++.dg/modules/clone-4_a.C: New test.
	* g++.dg/modules/clone-4_b.C: New test.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Jason Merrill <jason@redhat.com>
---

diff --git a/gcc/cp/optimize.cc b/gcc/cp/optimize.cc
index 8429d856728..e8e707516d6 100644
--- a/gcc/cp/optimize.cc
+++ b/gcc/cp/optimize.cc
@@ -309,8 +309,8 @@ maybe_thunk_body (tree fn, bool force)
       defer_mangling_aliases = save_defer_mangling_aliases;
       cgraph_node::get_create (fns[0])->set_comdat_group (comdat_group);
       cgraph_node::get_create (fns[1])->add_to_same_comdat_group
-	(cgraph_node::get_create (fns[0]));
-      symtab_node::get (fn)->add_to_same_comdat_group
+	(cgraph_node::get (fns[0]));
+      symtab_node::get_create (fn)->add_to_same_comdat_group
 	(symtab_node::get (fns[0]));
       if (fns[2])
 	/* If *[CD][12]* dtors go into the *[CD]5* comdat group and dtor is
diff --git a/gcc/testsuite/g++.dg/modules/clone-4_a.C b/gcc/testsuite/g++.dg/modules/clone-4_a.C
new file mode 100644
index 00000000000..bd74f588c7e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/clone-4_a.C
@@ -0,0 +1,12 @@
+// PR c++/120125
+// { dg-additional-options "-fmodules-ts -fdeclone-ctor-dtor" }
+// { dg-module-cmi M }
+
+export module M;
+
+void foo();
+export template <typename _Tp> struct __shared_ptr {
+  inline __shared_ptr() { foo(); }
+};
+
+template class __shared_ptr<int>;
diff --git a/gcc/testsuite/g++.dg/modules/clone-4_b.C b/gcc/testsuite/g++.dg/modules/clone-4_b.C
new file mode 100644
index 00000000000..0487dc2e395
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/clone-4_b.C
@@ -0,0 +1,12 @@
+// PR c++/120125
+// { dg-additional-options "-fmodules-ts -fdeclone-ctor-dtor" }
+
+import M;
+
+int main() {
+  __shared_ptr<int> s1;
+  __shared_ptr<double> s2;
+}
+
+// { dg-final { scan-assembler-not {_ZNW1M12__shared_ptrIiEC[1-4]Ev:} { xfail *-*-* } } }
+// { dg-final { scan-assembler {_ZNW1M12__shared_ptrIdEC2Ev:} } }