On Thu, Mar 1, 2018 at 2:12 PM, Marek Polacek <pola...@redhat.com> wrote: > In this testcase we find ourselves in split_nonconstant_init: > > init = cp_fully_fold (init); > code = push_stmt_list (); > if (split_nonconstant_init_1 (dest, init)) > > where initially INIT was a CONSTRUCTOR, but cp_fully_fold returned > a TARGET_EXPR. This confuses split_nonconstant_init_1 which only expects > a CONSTRUCTOR or a VECTOR_CST. Jason suggested stripping TARGET_EXPRs / > VIEW_CONVERT_EXPRs, so here it is. > > Bootstrapped/regtested on x86_64-linux, ok for trunk? > > 2018-03-01 Marek Polacek <pola...@redhat.com> > > PR c++/84590 > * cp-gimplify.c (cp_fully_fold): Unwrap TARGET_EXPR or a CONSTRUCTOR > wrapped in VIEW_CONVERT_EXPR. > > * c-c++-common/ubsan/shift-11.c: New test. > > diff --git gcc/cp/cp-gimplify.c gcc/cp/cp-gimplify.c > index 55a9d278dbe..1fa9c466e6b 100644 > --- gcc/cp/cp-gimplify.c > +++ gcc/cp/cp-gimplify.c > @@ -2038,7 +2038,18 @@ cp_fully_fold (tree x) > have to call both. */ > if (cxx_dialect >= cxx11) > x = maybe_constant_value (x); > - return cp_fold_rvalue (x); > + x = cp_fold_rvalue (x); > + > + /* Sometimes we are given a CONSTRUCTOR but > cxx_eval_outermost_constant_expr > + wraps it into a TARGET_EXPR; undo that here. */ > + if (TREE_CODE (x) == TARGET_EXPR) > + x = TARGET_EXPR_INITIAL (x); > + else if (TREE_CODE (x) == VIEW_CONVERT_EXPR > + && TREE_CODE (TREE_OPERAND (x, 0)) == CONSTRUCTOR > + && TREE_TYPE (TREE_OPERAND (x, 0)) == TREE_TYPE (x)) > + x = TREE_OPERAND (x, 0);
I think this should happen in the block with maybe_constant_value; cp_fold_rvalue doesn't do this. Jason
