c++: lambda capture and explicit object parm

More adjustments to allow for explicit object parameters in lambdas.  This
has no practical effect until that patch goes in, but applying this
separately seems reasonable.

gcc/cp/ChangeLog:

	* semantics.cc (finish_non_static_data_member)
	(finish_decltype_type, capture_decltype):
	Handle deduced closure parameter.

gcc/cp/semantics.cc

@@ -2262,6 +2262,16 @@ finish_non_static_data_member (tree decl, tree object, tree qualifying_scope,
       else if (PACK_EXPANSION_P (type))
 	/* Don't bother trying to represent this.  */
 	type = NULL_TREE;
+      else if (WILDCARD_TYPE_P (TREE_TYPE (object)))
+	/* We don't know what the eventual quals will be, so punt until
+	   instantiation time.
+
+	   This can happen when called from build_capture_proxy for an explicit
+	   object lambda.  It's a bit marginal to call this function in that
+	   case, since this function is for references to members of 'this',
+	   but the deduced type is required to be derived from the closure
+	   type, so it works.  */
+	type = NULL_TREE;
       else
 	{
 	  /* Set the cv qualifiers.  */
@@ -11682,6 +11692,7 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p,
      A<decltype(sizeof(T))>::U doesn't require 'typename'.  */
   if (instantiation_dependent_uneval_expression_p (expr))
     {
+    dependent:
       type = cxx_make_type (DECLTYPE_TYPE);
       DECLTYPE_TYPE_EXPR (type) = expr;
       DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (type)
@@ -11856,7 +11867,11 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p,
       if (outer_automatic_var_p (STRIP_REFERENCE_REF (expr))
 	  && current_function_decl
 	  && LAMBDA_FUNCTION_P (current_function_decl))
-	type = capture_decltype (STRIP_REFERENCE_REF (expr));
+	{
+	  type = capture_decltype (STRIP_REFERENCE_REF (expr));
+	  if (!type)
+	    goto dependent;
+	}
       else if (error_operand_p (expr))
 	type = error_mark_node;
       else if (expr == current_class_ptr)
@@ -12754,7 +12769,8 @@ apply_deduced_return_type (tree fco, tree return_type)
 
 /* DECL is a local variable or parameter from the surrounding scope of a
    lambda-expression.  Returns the decltype for a use of the capture field
-   for DECL even if it hasn't been captured yet.  */
+   for DECL even if it hasn't been captured yet.  Or NULL_TREE if we can't give
+   a correct answer at this point and we should build a DECLTYPE_TYPE.  */
 
 static tree
 capture_decltype (tree decl)
@@ -12792,9 +12808,11 @@ capture_decltype (tree decl)
 
   if (!TYPE_REF_P (type))
     {
-      int quals = cp_type_quals (type);
       tree obtype = TREE_TYPE (DECL_ARGUMENTS (current_function_decl));
-      gcc_checking_assert (!WILDCARD_TYPE_P (non_reference (obtype)));
+      if (WILDCARD_TYPE_P (non_reference (obtype)))
+	/* We don't know what the eventual obtype quals will be.  */
+	return NULL_TREE;
+      int quals = cp_type_quals (type);
       if (INDIRECT_TYPE_P (obtype))
 	quals |= cp_type_quals (TREE_TYPE (obtype));
       type = cp_build_qualified_type (type, quals);