From 14e9820ddef8026797810979ba66e32696c058cc Mon Sep 17 00:00:00 2001
From: nathan <nathan@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 27 Apr 2017 13:56:35 +0300
Subject: PR c++/79296 - ICE mangling localized template instantiation        
 * decl2.c (determine_visibility): Use template fn context for         local
 class instantiations.

        PR c++/79296
        * g++.dg/cpp0x/pr79296.C: New.

Change-Id: I51b9ba39a48a97a8836976baf5f598ede9ba695a
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@245398 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/cp/decl2.c                       | 41 ++++++++++++++++++------------------
 gcc/testsuite/g++.dg/cpp0x/pr79296.C | 18 ++++++++++++++++
 2 files changed, 39 insertions(+), 20 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/pr79296.C

diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index c4a0e854228..a9511dece51 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -2280,11 +2280,6 @@ constrain_visibility_for_template (tree decl, tree targs)
 void
 determine_visibility (tree decl)
 {
-  tree class_type = NULL_TREE;
-  bool use_template;
-  bool orig_visibility_specified;
-  enum symbol_visibility orig_visibility;
-
   /* Remember that all decls get VISIBILITY_DEFAULT when built.  */
 
   /* Only relevant for names with external linkage.  */
@@ -2296,25 +2291,28 @@ determine_visibility (tree decl)
      maybe_clone_body.  */
   gcc_assert (!DECL_CLONED_FUNCTION_P (decl));
 
-  orig_visibility_specified = DECL_VISIBILITY_SPECIFIED (decl);
-  orig_visibility = DECL_VISIBILITY (decl);
+  bool orig_visibility_specified = DECL_VISIBILITY_SPECIFIED (decl);
+  enum symbol_visibility orig_visibility = DECL_VISIBILITY (decl);
 
+  /* The decl may be a template instantiation, which could influence
+     visibilty.  */
+  tree template_decl = NULL_TREE;
   if (TREE_CODE (decl) == TYPE_DECL)
     {
       if (CLASS_TYPE_P (TREE_TYPE (decl)))
-	use_template = CLASSTYPE_USE_TEMPLATE (TREE_TYPE (decl));
+	{
+	  if (CLASSTYPE_USE_TEMPLATE (TREE_TYPE (decl)))
+	    template_decl = decl;
+	}
       else if (TYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
-	use_template = 1;
-      else
-	use_template = 0;
+	template_decl = decl;
     }
-  else if (DECL_LANG_SPECIFIC (decl))
-    use_template = DECL_USE_TEMPLATE (decl);
-  else
-    use_template = 0;
+  else if (DECL_LANG_SPECIFIC (decl) && DECL_USE_TEMPLATE (decl))
+    template_decl = decl;
 
   /* If DECL is a member of a class, visibility specifiers on the
      class can influence the visibility of the DECL.  */
+  tree class_type = NULL_TREE;
   if (DECL_CLASS_SCOPE_P (decl))
     class_type = DECL_CONTEXT (decl);
   else
@@ -2357,8 +2355,11 @@ determine_visibility (tree decl)
 	    }
 
 	  /* Local classes in templates have CLASSTYPE_USE_TEMPLATE set,
-	     but have no TEMPLATE_INFO, so don't try to check it.  */
-	  use_template = 0;
+	     but have no TEMPLATE_INFO.  Their containing template
+	     function does, and the local class could be constrained
+	     by that.  */
+	  if (template_decl)
+	    template_decl = fn;
 	}
       else if (VAR_P (decl) && DECL_TINFO_P (decl)
 	       && flag_visibility_ms_compat)
@@ -2388,7 +2389,7 @@ determine_visibility (tree decl)
 	      && !CLASSTYPE_VISIBILITY_SPECIFIED (TREE_TYPE (DECL_NAME (decl))))
 	    targetm.cxx.determine_class_data_visibility (decl);
 	}
-      else if (use_template)
+      else if (template_decl)
 	/* Template instantiations and specializations get visibility based
 	   on their template unless they override it with an attribute.  */;
       else if (! DECL_VISIBILITY_SPECIFIED (decl))
@@ -2405,11 +2406,11 @@ determine_visibility (tree decl)
 	}
     }
 
-  if (use_template)
+  if (template_decl)
     {
       /* If the specialization doesn't specify visibility, use the
 	 visibility from the template.  */
-      tree tinfo = get_template_info (decl);
+      tree tinfo = get_template_info (template_decl);
       tree args = TI_ARGS (tinfo);
       tree attribs = (TREE_CODE (decl) == TYPE_DECL
 		      ? TYPE_ATTRIBUTES (TREE_TYPE (decl))
diff --git a/gcc/testsuite/g++.dg/cpp0x/pr79296.C b/gcc/testsuite/g++.dg/cpp0x/pr79296.C
new file mode 100644
index 00000000000..1ee982c71f0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/pr79296.C
@@ -0,0 +1,18 @@
+// { dg-do compile { target c++11 } }
+// { dg-require-effective-target lto }
+// { dg-additional-options "-flto" }
+
+// PR 79296 ICE mangling local class of localized instantiation
+
+struct X {
+  template <typename T> X (T const *) {
+    struct Z {};
+  }
+};
+
+void Baz ()
+{
+  struct Y { } y;
+
+  0, X (&y);
+}
-- 
cgit v1.2.3