Hi,
this ICE on invalid seems quite similar to c++/69637 which I fixed
recently: we again end up with an unhandled OVERLOAD in the main
cxx_eval_constant_expression switch and in this case we don't diagnose
at all the invalid input. Thus, I propose to add a check to
cxx_alignas_expr completely similar to what we have in grokbitfield on
the width. Tested x86_64-linux.
Thanks, Paolo.
PS: I think we are moving away from pretty printing (%qE) expressions,
thus I dind't try in the patchlet to print the argument, only its
(wrong) type.
//////////////////////
/cp
2017-02-17 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/79380
* typeck.c (cxx_alignas_expr): Reject a non-integral alignas
argument.
/testsuite
2017-02-17 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/79380
* g++.dg/cpp0x/alignas8.C: New.
Index: cp/typeck.c
===================================================================
--- cp/typeck.c (revision 245503)
+++ cp/typeck.c (working copy)
@@ -1795,6 +1795,12 @@ cxx_alignas_expr (tree e)
the assignment-expression shall be an integral constant
expression. */
+
+ if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (e)))
+ {
+ error ("%<alignas%> argument has non-integral type %qT", TREE_TYPE (e));
+ return error_mark_node;
+ }
return cxx_constant_value (e);
}
Index: testsuite/g++.dg/cpp0x/alignas8.C
===================================================================
--- testsuite/g++.dg/cpp0x/alignas8.C (revision 0)
+++ testsuite/g++.dg/cpp0x/alignas8.C (working copy)
@@ -0,0 +1,7 @@
+// PR c++/79380
+// { dg-do compile { target c++11 } }
+
+template < typename > constexpr int f () { return 8; }
+
+// should have been: struct alignas (f<int>()) S {};
+struct alignas (f) S {}; // { dg-error "17:'alignas' argument has
non-integral type" }
