[C++ Patch] PR 60314 (ICE with decltype(auto))

[Paolo Carlini]

Hi,

here we ICE exactly as we did in c++/53756: the only difference is the 
use of decltype(auto) instead of auto. Now, if we compare is_cxx_auto to 
is_auto (the front-end helper), evidently there is an inconsistency 
about the handling of decltype(auto) and the below fixes the ICE. 
However, also clearly the patchlet needs a review, because an out of 
class decltype(auto) is already fine. Also, I'm not 100% sure we don't 
need a decltype_auto_die, etc.

Tested x86_64-linux.

Thanks,
Paolo.

///////////////////////
2014-02-25  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/60314
        * dwarf2out.c (is_cxx_auto): Handle decltype(auto).

/testsuite
2014-02-25  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/60314
        * g++.dg/cpp1y/auto-fn24.C: New.
Index: dwarf2out.c
===================================================================
--- dwarf2out.c (revision 208113)
+++ dwarf2out.c (working copy)
@@ -10230,7 +10230,8 @@ is_cxx_auto (tree type)
       tree name = TYPE_NAME (type);
       if (TREE_CODE (name) == TYPE_DECL)
        name = DECL_NAME (name);
-      if (name == get_identifier ("auto"))
+      if (name == get_identifier ("auto")
+         || name == get_identifier ("decltype(auto)"))
        return true;
     }
   return false;
Index: testsuite/g++.dg/cpp1y/auto-fn24.C
===================================================================
--- testsuite/g++.dg/cpp1y/auto-fn24.C  (revision 0)
+++ testsuite/g++.dg/cpp1y/auto-fn24.C  (working copy)
@@ -0,0 +1,12 @@
+// PR c++/60314
+// { dg-options "-std=c++1y -g" }
+
+// fine
+decltype(auto) qux() { return 42; }
+
+struct foo
+{
+  // also ICEs if not static 
+  static decltype(auto) bar()
+  { return 42; }
+};