1 files changed, 43 insertions, 36 deletions

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index d63fa68..acfeb81 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -6952,14 +6952,22 @@ convert_nontype_argument_function (tree type, tree expr,
 	{
 	  auto_diagnostic_group d;
 	  location_t loc = cp_expr_loc_or_input_loc (expr);
-	  error_at (loc, "%qE is not a valid template argument for type %qT",
-		    expr, type);
-	  if (TYPE_PTR_P (type))
-	    inform (loc, "it must be the address of a function "
-		    "with external linkage");
+	  tree c;
+	  if (cxx_dialect >= cxx17
+	      && (c = cxx_constant_value (fn),
+		  c == error_mark_node))
+	    ;
 	  else
-	    inform (loc, "it must be the name of a function with "
-		    "external linkage");
+	    {
+	      error_at (loc, "%qE is not a valid template argument for "
+			"type %qT", expr, type);
+	      if (TYPE_PTR_P (type))
+		inform (loc, "it must be the address of a function "
+			"with external linkage");
+	      else
+		inform (loc, "it must be the name of a function with "
+			"external linkage");
+	    }
 	}
       return NULL_TREE;
     }
@@ -7402,22 +7410,22 @@ invalid_tparm_referent_p (tree type, tree expr, tsubst_flags_t complain)
 	/* Null pointer values are OK in C++11.  */;
       else
 	{
-	  if (VAR_P (expr))
-	    {
-	      if (complain & tf_error)
-		error ("%qD is not a valid template argument "
-		       "because %qD is a variable, not the address of "
-		       "a variable", expr, expr);
-	      return true;
-	    }
+	  tree c;
+	  if (!(complain & tf_error))
+	    ;
+	  else if (cxx_dialect >= cxx17
+		   && (c = cxx_constant_value (expr),
+		       c == error_mark_node))
+	    ;
+	  else if (VAR_P (expr))
+	    error ("%qD is not a valid template argument "
+		   "because %qD is a variable, not the address of "
+		   "a variable", expr, expr);
 	  else
-	    {
-	      if (complain & tf_error)
-		error ("%qE is not a valid template argument for %qT "
-		       "because it is not the address of a variable",
-		       expr, type);
-	      return true;
-	    }
+	    error ("%qE is not a valid template argument for %qT "
+		   "because it is not the address of a variable",
+		   expr, type);
+	  return true;
 	}
     }
   return false;
@@ -14916,6 +14924,9 @@ tsubst_function_decl (tree t, tree args, tsubst_flags_t complain,
       argvec = NULL_TREE;
     }
 
+  /* Make sure tsubst_decl substitutes all the parameters.  */
+  cp_evaluated ev;
+
   tree closure = (lambda_fntype ? TYPE_METHOD_BASETYPE (lambda_fntype)
 		  : NULL_TREE);
   tree ctx = closure ? closure : DECL_CONTEXT (t);
@@ -19590,7 +19601,8 @@ tsubst_stmt (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 
 	finish_static_assert (condition, message,
                               STATIC_ASSERT_SOURCE_LOCATION (t),
-			      /*member_p=*/false, /*show_expr_p=*/true);
+			      /*member_p=*/false, /*show_expr_p=*/true,
+			      CONSTEVAL_BLOCK_P (t));
       }
       break;
 
@@ -20494,11 +20506,6 @@ tsubst_lambda_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
     r = error_mark_node;
   else
     {
-      /* The body of a lambda-expression is not a subexpression of the
-	 enclosing expression.  Parms are to have DECL_CHAIN tsubsted,
-	 which would be skipped if cp_unevaluated_operand.  */
-      cp_evaluated ev;
-
       /* Fix the type of 'this'.
 	 For static and xobj member functions we use this to transport the
 	 lambda's closure type.  It appears that in the regular case the
@@ -20524,6 +20531,10 @@ tsubst_lambda_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
       /* Let finish_function set this.  */
       DECL_DECLARED_CONSTEXPR_P (fn) = false;
 
+      /* The body of a lambda-expression is not a subexpression of the
+	 enclosing expression.  */
+      cp_evaluated ev;
+
       bool nested = cfun;
       if (nested)
 	push_function_context ();
@@ -31214,14 +31225,8 @@ alias_ctad_tweaks (tree tmpl, tree uguides)
 	  /* Substitute the deduced arguments plus the rewritten template
 	     parameters into f to get g.  This covers the type, copyness,
 	     guideness, and explicit-specifier.  */
-	  tree g;
-	    {
-	      /* Parms are to have DECL_CHAIN tsubsted, which would be skipped
-		 if cp_unevaluated_operand.  */
-	      cp_evaluated ev;
-	      g = tsubst_decl (DECL_TEMPLATE_RESULT (f), targs, complain,
+	  tree g = tsubst_decl (DECL_TEMPLATE_RESULT (f), targs, complain,
 			       /*use_spec_table=*/false);
-	    }
 	  if (g == error_mark_node)
 	    continue;
 	  DECL_NAME (g) = name;
@@ -31651,7 +31656,9 @@ do_class_deduction (tree ptype, tree tmpl, tree init, tree outer_targs,
 	  /* Be permissive with equivalent alias templates.  */
 	  tree u = get_underlying_template (tmpl);
 	  auto_diagnostic_group d;
-	  diagnostic_t dk = (u == tmpl) ? DK_ERROR : DK_PEDWARN;
+	  const enum diagnostics::kind dk = ((u == tmpl)
+					     ? diagnostics::kind::error
+					     : diagnostics::kind::pedwarn);
 	  bool complained
 	    = emit_diagnostic (dk, input_location, 0,
 			       "alias template deduction only available "