re PR c++/84942 (internal compiler error: in fold_convert_const_int_from_real,…

re PR c++/84942 (internal compiler error: in fold_convert_const_int_from_real, at fold-const.c:2011)

	PR c++/84942
	* pt.c (tsubst_copy_and_build) <case FIX_TRUNC_EXPR>: Replace
	cp_build_unary_op call with gcc_unreachable ().

	* g++.dg/cpp1y/pr84942.C: New test.

From-SVN: r258821

gcc/cp/ChangeLog

+2018-03-23  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/84942
+	* pt.c (tsubst_copy_and_build) <case FIX_TRUNC_EXPR>: Replace
+	cp_build_unary_op call with gcc_unreachable ().
+
 2018-03-23  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/85045

gcc/cp/pt.c

@@ -17514,8 +17514,7 @@ tsubst_copy_and_build (tree t,
 				complain|decltype_flag));
 
     case FIX_TRUNC_EXPR:
-      RETURN (cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)),
-				 false, complain));
+      gcc_unreachable ();    
 
     case ADDR_EXPR:
       op1 = TREE_OPERAND (t, 0);

gcc/testsuite/ChangeLog

+2018-03-23  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/84942
+	* g++.dg/cpp1y/pr84942.C: New test.
+
 2018-03-23  Vladimir Makarov  <vmakarov@redhat.com>
 
 	PR inline-asm/85030

gcc/testsuite/g++.dg/cpp1y/pr84942.C

+// PR c++/84942
+// { dg-do compile { target c++14 } }
+// { dg-options "-w" }
+
+int a(__attribute__((b((int)__builtin_inf() * 1ULL / auto))));
+// { dg-error "expected primary-expression before" "" { target *-*-* } .-1 }