From 71f484d02b2b3e8616cd7af27a0d4c72e4c7e977 Mon Sep 17 00:00:00 2001
From: Marek Polacek <polacek@redhat.com>
Date: Tue, 18 Jun 2024 10:50:49 -0400
Subject: c++: ICE with __dynamic_cast redecl [PR115501]

Since r13-3299, build_dynamic_cast_1 calls pushdecl which calls
duplicate_decls and that in this testcase emits the "conflicting
declaration" error and returns error_mark_node, so the subsequent
build_cxx_call crashes on the error_mark_node.

	PR c++/115501

gcc/cp/ChangeLog:

	* rtti.cc (build_dynamic_cast_1): Return if dcast_fn is erroneous.

gcc/testsuite/ChangeLog:

	* g++.dg/rtti/dyncast8.C: New test.
---
 gcc/testsuite/g++.dg/rtti/dyncast8.C | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/rtti/dyncast8.C

(limited to 'gcc/testsuite/g++.dg')

diff --git a/gcc/testsuite/g++.dg/rtti/dyncast8.C b/gcc/testsuite/g++.dg/rtti/dyncast8.C
new file mode 100644
index 0000000..de23433
--- /dev/null
+++ b/gcc/testsuite/g++.dg/rtti/dyncast8.C
@@ -0,0 +1,15 @@
+// PR c++/115501
+// { dg-do compile }
+
+struct s{virtual void f();};
+struct s1 : s{};
+namespace __cxxabiv1
+{
+  extern "C" void __dynamic_cast(); // { dg-message "previous declaration" }
+}
+void diagnostic_information_impl(s const *se)
+{
+  dynamic_cast<s1 const *>(se);
+}
+
+// { dg-error "conflicting declaration" "" { target *-*-* } 0 }
-- 
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