From 8945521a50a7dd26ffebdee20a82e323141dfd8b Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Wed, 27 Jun 2018 13:29:51 -0400
Subject: [PATCH] Avoid crash on friend in nested class template.

	* name-lookup.c (do_pushtag): If we skip a class level, also skip
	its template level.

From-SVN: r262188
---
 gcc/cp/ChangeLog                              |  5 +++
 gcc/cp/name-lookup.c                          | 38 ++++++++++++-------
 gcc/testsuite/g++.dg/template/friend66.C      |  9 +++++
 .../g++.old-deja/g++.law/visibility13.C       | 10 +++--
 4 files changed, 44 insertions(+), 18 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/template/friend66.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 90d1545d734..05383b6003a 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2018-06-27  Jason Merrill  <jason@redhat.com>
+
+	* name-lookup.c (do_pushtag): If we skip a class level, also skip
+	its template level.
+
 2018-06-26  Jason Merrill  <jason@redhat.com>
 
 	PR c++/86320 - memory-hog with std::array of pair
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index a30c37428ad..e0500d83071 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -6509,20 +6509,30 @@ do_pushtag (tree name, tree type, tag_scope scope)
   tree decl;
 
   cp_binding_level *b = current_binding_level;
-  while (/* Cleanup scopes are not scopes from the point of view of
-	    the language.  */
-	 b->kind == sk_cleanup
-	 /* Neither are function parameter scopes.  */
-	 || b->kind == sk_function_parms
-	 /* Neither are the scopes used to hold template parameters
-	    for an explicit specialization.  For an ordinary template
-	    declaration, these scopes are not scopes from the point of
-	    view of the language.  */
-	 || (b->kind == sk_template_parms
-	     && (b->explicit_spec_p || scope == ts_global))
-	 || (b->kind == sk_class
-	     && scope != ts_current))
-    b = b->level_chain;
+  while (true)
+    {
+      if (/* Cleanup scopes are not scopes from the point of view of
+	     the language.  */
+	  b->kind == sk_cleanup
+	  /* Neither are function parameter scopes.  */
+	  || b->kind == sk_function_parms
+	  /* Neither are the scopes used to hold template parameters
+	     for an explicit specialization.  For an ordinary template
+	     declaration, these scopes are not scopes from the point of
+	     view of the language.  */
+	  || (b->kind == sk_template_parms
+	      && (b->explicit_spec_p || scope == ts_global)))
+	b = b->level_chain;
+      else if (b->kind == sk_class
+	       && scope != ts_current)
+	{
+	  b = b->level_chain;
+	  if (b->kind == sk_template_parms)
+	    b = b->level_chain;
+	}
+      else
+	break;
+    }
 
   gcc_assert (identifier_p (name));
 
diff --git a/gcc/testsuite/g++.dg/template/friend66.C b/gcc/testsuite/g++.dg/template/friend66.C
new file mode 100644
index 00000000000..f8c95f844b3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/friend66.C
@@ -0,0 +1,9 @@
+template <class T>
+struct A
+{
+  template <class U>
+  struct B
+  {
+    friend struct C;
+  };
+};
diff --git a/gcc/testsuite/g++.old-deja/g++.law/visibility13.C b/gcc/testsuite/g++.old-deja/g++.law/visibility13.C
index 025b0b1ef54..451ef1afaf8 100644
--- a/gcc/testsuite/g++.old-deja/g++.law/visibility13.C
+++ b/gcc/testsuite/g++.old-deja/g++.law/visibility13.C
@@ -15,9 +15,11 @@ using namespace std;
 
 const int ArraySize = 12;
 
+template <class> class Array_RC;
+
 template <class Type>
-class Array { // { dg-error "" } .struct Array_RC redecl.*
-friend class Array_RC;
+class Array {
+  friend class Array_RC<Type>;
 public:
     Array(const Type *ar, int sz) { init(ar,sz); }
     virtual ~Array() { delete [] ia; }
@@ -76,8 +78,8 @@ Array_RC<Type>::Array_RC(const Type *ar, int sz) : Array<Type>(ar, sz) {}
 
 template <class Type>
 Type &Array_RC<Type>::operator[](int ix) {
-    assert(ix >= 0 && ix < size);// { dg-error "" } member .size.*
-    return ia[ix];// { dg-error "" } member .ia.*
+    assert(ix >= 0 && ix < this->size);
+    return this->ia[ix];
 }
 
 //    -------------------   Test routine   ----------------------
-- 
2.30.2