c++: ICE with anonymous union [PR97974]

Here lookup got confused by finding a conversion operator from
lookup_anon_field.  Let's avoid this by pruning functions from
CLASSTYPE_MEMBER_VEC as well as TYPE_FIELDS.

gcc/cp/ChangeLog:

	PR c++/97974
	* decl.c (fixup_anonymous_aggr): Prune all functions from
	CLASSTYPE_MEMBER_VEC.

gcc/testsuite/ChangeLog:

	PR c++/97974
	* g++.dg/lookup/pr84962.C: Adjust diagnostic.
	* g++.dg/other/anon-union5.C: New test.

3 files changed, 18 insertions, 1 deletions

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 3294b4f..ec05ee1 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -5005,6 +5005,14 @@ fixup_anonymous_aggr (tree t)
     else
       prev_p = &DECL_CHAIN (probe);
 
+  /* Splice all functions out of CLASSTYPE_MEMBER_VEC.  */
+  vec<tree,va_gc>* vec = CLASSTYPE_MEMBER_VEC (t);
+  unsigned store = 0;
+  for (tree elt : vec)
+    if (!is_overloaded_fn (elt))
+      (*vec)[store++] = elt;
+  vec_safe_truncate (vec, store);
+
   /* Anonymous aggregates cannot have fields with ctors, dtors or complex
      assignment operators (because they cannot have these methods themselves).
      For anonymous unions this is already checked because they are not allowed
diff --git a/gcc/testsuite/g++.dg/lookup/pr84962.C b/gcc/testsuite/g++.dg/lookup/pr84962.C
index b9b7a31..c22b95c 100644
--- a/gcc/testsuite/g++.dg/lookup/pr84962.C
+++ b/gcc/testsuite/g++.dg/lookup/pr84962.C
@@ -9,6 +9,6 @@ struct X {
     // { dg-error "public non-static data member" "" { target *-*-* } .-1 }
   };
 
-  int  : a; // { dg-error "non-integral" }
+  int  : a; // { dg-error "" }
 };
 
diff --git a/gcc/testsuite/g++.dg/other/anon-union5.C b/gcc/testsuite/g++.dg/other/anon-union5.C
new file mode 100644
index 0000000..616dea8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/other/anon-union5.C
@@ -0,0 +1,9 @@
+// PR c++/97974
+
+struct A {
+  union {
+    operator int ();		// { dg-error "anonymous union" }
+    int a;
+  };
+  operator int;			// { dg-error "" }
+};