Various small fixes.

	* lambda.c (build_lambda_object): Check for error_mark_node.
	* pt.c (make_pack_expansion): Set PACK_EXPANSION_LOCAL_P on the type
	pack as well.
	(tsubst_decl) [FUNCTION_DECL]: Set DECL_CONTEXT on the parameters.
	(tsubst) [TEMPLATE_PARM_INDEX]: Check for error_mark_node.

From-SVN: r251428

gcc/cp/ChangeLog

+2017-08-23  Jason Merrill  <jason@redhat.com>
+
+	* lambda.c (build_lambda_object): Check for error_mark_node.
+	* pt.c (make_pack_expansion): Set PACK_EXPANSION_LOCAL_P on the type
+	pack as well.
+	(tsubst_decl) [FUNCTION_DECL]: Set DECL_CONTEXT on the parameters.
+	(tsubst) [TEMPLATE_PARM_INDEX]: Check for error_mark_node.
+
 2017-08-29  Jason Merrill  <jason@redhat.com>
 
 	PR c++/80767 - unnecessary instantiation of generic lambda

gcc/cp/constexpr.c

@@ -1458,7 +1458,8 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
     {
       if (!ctx->quiet)
 	{
-	  error_at (loc, "call to non-constexpr function %qD", fun);
+	  if (!lambda_static_thunk_p (fun))
+	    error_at (loc, "call to non-constexpr function %qD", fun);
 	  explain_invalid_constexpr_fn (fun);
 	}
       *non_constant_p = true;

gcc/cp/lambda.c

@@ -59,7 +59,7 @@ build_lambda_object (tree lambda_expr)
   tree node, expr, type;
   location_t saved_loc;
 
-  if (processing_template_decl)
+  if (processing_template_decl || lambda_expr == error_mark_node)
     return lambda_expr;
 
   /* Make sure any error messages refer to the lambda-introducer.  */

gcc/cp/pt.c

@@ -3773,6 +3773,7 @@ make_pack_expansion (tree arg)
       purpose = cxx_make_type (TYPE_PACK_EXPANSION);
       SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
       PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
+      PACK_EXPANSION_LOCAL_P (purpose) = at_function_scope_p ();
 
       /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
 	 they will rarely be compared to anything.  */
@@ -9535,6 +9536,7 @@ static inline bool
 neglectable_inst_p (tree d)
 {
   return (DECL_P (d)
+	  && !undeduced_auto_decl (d)
 	  && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
 	       : decl_maybe_constant_var_p (d)));
 }
@@ -12413,6 +12415,8 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
 
 	DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
 				     complain, t);
+	for (tree parm = DECL_ARGUMENTS (r); parm; parm = DECL_CHAIN (parm))
+	  DECL_CONTEXT (parm) = r;
 	DECL_RESULT (r) = NULL_TREE;
 
 	TREE_STATIC (r) = 0;
@@ -13786,6 +13790,8 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 	       couldn't do it earlier because it might be an auto parameter,
 	       and we wouldn't need to if we had an argument.  */
 	    type = tsubst (type, args, complain, in_decl);
+	    if (type == error_mark_node)
+	      return error_mark_node;
 	    r = reduce_template_parm_level (t, type, levels, args, complain);
 	    break;