Re: [PATCH] handle multiple flexible array members (PR 83588)

[Martin Sebor <msebor at gmail dot com>]

On 01/15/2018 07:10 PM, Jason Merrill wrote:
> OK.

Thanks.  I keep forgetting to get approval to backport these
simple bug fixes.  Is this one okay for the 7 and 6 branches?

Martin

> On Sun, Jan 14, 2018 at 6:47 PM, Martin Sebor <msebor@gmail.com> wrote:
> > The attached patch fixes PR c++/83588 - struct with two flexible
> > arrays causes an internal compiler error.  The ICE is caused by
> > the same assertion in varasm.c that has led to other similar
> > reports in the past:
> >
> >   /* Given a non-empty initialization, this field had better
> >      be last.  Given a flexible array member, the next field
> >      on the chain is a TYPE_DECL of the enclosing struct.  */
> >   const_tree next = DECL_CHAIN (local->field);
> >   gcc_assert (!fieldsize || !next || TREE_CODE (next) != FIELD_DECL);
> >
> > The fix is simply to also detect when a class defines more than
> > one flexible array member and treat the subsequent array as any
> > other member, and reject such class definitions to make sure they
> > never reach the assertion above.
> >
> > Martin