re PR c++/47808 ([C++0x] internal compiler error: in tsubst_copy_and_build, at cp/pt.c:13326)

	PR c++/47808
	* decl.c (compute_array_index_type): Discard folding
	if it didn't produce a constant.

From-SVN: r170878

gcc/cp/ChangeLog

+2011-03-11  Jason Merrill  <jason@redhat.com>
+
+	PR c++/47808
+	* decl.c (compute_array_index_type): Discard folding
+	if it didn't produce a constant.
+
 2011-03-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/48035

gcc/cp/decl.c

@@ -7523,6 +7523,8 @@ compute_array_index_type (tree name, tree size, tsubst_flags_t complain)
 	    }
 
 	  size = maybe_constant_value (size);
+	  if (!TREE_CONSTANT (size))
+	    size = osize;
 	}
 
       if (error_operand_p (size))

gcc/testsuite/ChangeLog

+2011-03-11  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/cpp0x/regress/array1.C: New.
+
 2011-03-11  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/48067

gcc/testsuite/g++.dg/cpp0x/regress/array1.C

+// PR c++/47808
+// { dg-options -std=c++0x }
+
+template <typename T>
+inline T abs (T const & x) { return x; }
+
+template <typename T>
+void f (T)
+{
+  typedef int ai[(abs(0.1) > 0) ? 1 : -1];
+}
+
+int main()
+{
+  f(1);
+}