PR c++/82360 - ICE with static_cast in template.

	* call.c (perform_direct_initialization_if_possible): Check
	processing_template_decl.
	* typeck.c (build_static_cast_1): Likewise.

From-SVN: r254710

gcc/cp/ChangeLog

+2017-11-13  Jason Merrill  <jason@redhat.com>
+
+	PR c++/82360 - ICE with static_cast in template.
+	* call.c (perform_direct_initialization_if_possible): Check
+	processing_template_decl.
+	* typeck.c (build_static_cast_1): Likewise.
+
 2017-11-13  Ville Voutilainen  <ville.voutilainen@gmail.com>
 
 	Remove the null check from placement new in all modes

gcc/cp/call.c

@@ -10647,6 +10647,16 @@ perform_direct_initialization_if_possible (tree type,
 			      LOOKUP_NORMAL, complain);
   if (!conv || conv->bad_p)
     expr = NULL_TREE;
+  else if (processing_template_decl && conv->kind != ck_identity)
+    {
+      /* In a template, we are only concerned about determining the
+	 type of non-dependent expressions, so we do not have to
+	 perform the actual conversion.  But for initializers, we
+	 need to be able to perform it at instantiation
+	 (or instantiate_non_dependent_expr) time.  */
+      expr = build1 (IMPLICIT_CONV_EXPR, type, expr);
+      IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true;
+    }
   else
     expr = convert_like_real (conv, expr, NULL_TREE, 0,
 			      /*issue_conversion_warnings=*/false,

gcc/cp/typeck.c

@@ -6820,6 +6820,9 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
     {
       tree base;
 
+      if (processing_template_decl)
+	return expr;
+
       /* There is a standard conversion from "D*" to "B*" even if "B"
 	 is ambiguous or inaccessible.  If this is really a
 	 static_cast, then we check both for inaccessibility and
@@ -6864,6 +6867,8 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
       && reference_related_p (TREE_TYPE (type), intype)
       && (c_cast_p || at_least_as_qualified_p (TREE_TYPE (type), intype)))
     {
+      if (processing_template_decl)
+	return expr;
       if (clk == clk_ordinary)
 	{
 	  /* Handle the (non-bit-field) lvalue case here by casting to
@@ -6911,6 +6916,9 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
 						      c_cast_p, complain);
   if (result)
     {
+      if (processing_template_decl)
+	return expr;
+
       result = convert_from_reference (result);
 
       /* [expr.static.cast]
@@ -6952,7 +6960,11 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
        || SCALAR_FLOAT_TYPE_P (type))
       && (INTEGRAL_OR_ENUMERATION_TYPE_P (intype)
 	  || SCALAR_FLOAT_TYPE_P (intype)))
+    {
+      if (processing_template_decl)
+	return expr;
       return ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL, complain);
+    }
 
   if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
       && CLASS_TYPE_P (TREE_TYPE (type))
@@ -6965,6 +6977,9 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
     {
       tree base;
 
+      if (processing_template_decl)
+	return expr;
+
       if (!c_cast_p
 	  && check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR,
 					       complain))
@@ -7019,6 +7034,8 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
 						   STATIC_CAST_EXPR,
 						   complain))
 	    return error_mark_node;
+	  if (processing_template_decl)
+	    return expr;
 	  return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
 				 c_cast_p, complain);
 	}
@@ -7038,6 +7055,8 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
 	  && check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR,
 					       complain))
 	return error_mark_node;
+      if (processing_template_decl)
+	return expr;
       return build_nop (type, expr);
     }
 

gcc/testsuite/g++.dg/template/cast5.C

+// PR c++/82360
+// { dg-do compile { target c++11 } }
+
+class a {};
+template <class> class b {
+  b(b &&c) : d(static_cast<a &&>(c.d)) {}
+  a d;
+};