Re: C++ PATCHes relating to c++/48834, c++/40975 (array new)

[Jason Merrill <jason at redhat dot com>]

On 05/03/2011 11:52 AM, Eric Botcazou wrote:
> > In that case you wouldn't be affected by this patch; unshare_body uses
> > mostly_copy_tree_r, which has its own special case for STATEMENT_LIST.
>
> Right, I added it precisely to support statement expressions in Ada (instead
> of changing copy_tree_r) since we never want to copy them in the unsharing
> phase.  That's why I find the change to copy_tree_r questionable.

Well, let's look at the users of copy_tree_r.

cp/tree.c (bot_manip): The case I want to fix.

gimplify.c (mostly_copy_tree_r): Handles STATEMENT_LIST itself.

stor-layout.c (copy_self_referential_tree_r): Affected by the change. 
Would you like me to add a gcc_unreachable() here?

tree-inline.c (copy_tree_body_r): already copies STATEMENT_LIST itself 
(with a copy_statement_list function which I should use instead of 
open-coding it again).
(copy_bind_expr): subroutine of copy_tree_body_r.
(unsave_r, remap_gimple_op_r): Handle STATEMENT_LIST themselves.

So, looks like one place that could have an undesired change in 
behavior.  I'll go ahead and add that assert.

Jason