[pushed] c++: ICE on anon struct with base [PR96636]

[Jason Merrill via Gcc-patches]

pinskia pointed out that my recent change to reject anonymous structs with
bases was relevant to this PR.  But we still ICEd after giving that error;
this fixes the ICE.

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

        PR c++/96636

gcc/cp/ChangeLog:

        * decl.c (fixup_anonymous_aggr): Clear TYPE_NEEDS_CONSTRUCTING
        after error.

gcc/testsuite/ChangeLog:

        * g++.dg/ext/anon-struct9.C: New test.
---
 gcc/cp/decl.c                           | 6 +++++-
 gcc/testsuite/g++.dg/ext/anon-struct9.C | 9 +++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/ext/anon-struct9.C

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index e4be6be1819..6fa6b9adc87 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -5094,7 +5094,11 @@ fixup_anonymous_aggr (tree t)
       tree field, type;
 
       if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)))
-       error_at (location_of (t), "anonymous struct with base classes");
+       {
+         error_at (location_of (t), "anonymous struct with base classes");
+         /* Avoid ICE after error on anon-struct9.C.  */
+         TYPE_NEEDS_CONSTRUCTING (t) = false;
+       }
 
       for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
        if (TREE_CODE (field) == FIELD_DECL)
diff --git a/gcc/testsuite/g++.dg/ext/anon-struct9.C 
b/gcc/testsuite/g++.dg/ext/anon-struct9.C
new file mode 100644
index 00000000000..56759429620
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/anon-struct9.C
@@ -0,0 +1,9 @@
+// PR c++/96636
+// { dg-options "" }
+
+typedef class {
+  class a {};
+  class : virtual a {};                // { dg-error "anonymous struct with 
base" }
+} b;
+void foo(){ b();}
+

base-commit: 4c4249b71de3b15ba1e176ce90a57fb7bc54b917
prerequisite-patch-id: 62730bcaf1f07786fd756efb6f3bbd94d778c092
-- 
2.27.0