[Bug c++/52282] [C++0x] ICE / confused by earlier errors with decltype/constexpr

["paolo.carlini at oracle dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52282

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-05-07
                 CC|                            |paolo.carlini at oracle dot
                   |                            |com
     Ever Confirmed|0                           |1

--- Comment #6 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-05-07 09:50:43 UTC ---
For concreteness, with the below patchlet (for the record, about the
cxx_eval_call_expression bits, in build_data_member_initialization we have
something quite similar) all the test pass, besides the four lines:

static_assert((c.*W_<int(C::*)()const, &C::c1>::value)() == 10, "oops");
static_assert((c.*X_<int(C::*)()const, &C::c1>::value)() == 10, "oops");
static_assert((c.*Y_<int(C::*)()const, &C::c1>::value)() == 10, "oops");
static_assert((c.*Z_<int(C::*)()const, &C::c1>::value)() == 10, "oops");

///////////////

Index: semantics.c
===================================================================
--- semantics.c (revision 187228)
+++ semantics.c (working copy)
@@ -5269,6 +5269,7 @@ finish_decltype_type (tree expr, bool id_expressio

         case INTEGER_CST:
        case PTRMEM_CST:
+       case ADDR_EXPR:
           /* We can get here when the id-expression refers to an
              enumerator or non-type template parameter.  */
           type = TREE_TYPE (expr);
@@ -6488,6 +6489,12 @@ cxx_eval_call_expression (const constexpr_call *ol
       /* Might be a constexpr function pointer.  */
       fun = cxx_eval_constant_expression (old_call, fun, allow_non_constant,
                                          /*addr*/false, non_constant_p);
+      if (TREE_CODE (fun) == NOP_EXPR)
+       {
+         tree tmp = fun;
+         STRIP_NOPS (tmp);
+         fun = tmp;
+       }
       if (TREE_CODE (fun) == ADDR_EXPR)
        fun = TREE_OPERAND (fun, 0);
     }