On 05/25/2011 10:18 AM, Jason Merrill wrote: > On 05/25/2011 10:00 AM, Nathan Froyd wrote: >> Jason commented on the TS_STATEMENT_LIST patch, but >> the discussion didn't come to a resolution. > > Right, from your last mail I thought that you were investigating my question > about add_stmt and your suggestion about dropping the NULL checking in > append_to_statement_list_1.
Ah, OK. That was not clear to me. I stand by what I said about add_stmt. Before, if we weren't building_stmt_tree (i.e. cur_stmt_list was NULL), we'd just pass a pointer to NULL into append_to_statement_list and append_to_statement_list would DTRT. Now if we have a NULL stack, then passing a pointer to the stack doesn't work, because it's not typed correctly and we'd be clobbering the VEC, not pushing onto the stack. An alternative solution would be to initialize cur_stmt_list somewhere with an actual 1-element VEC; the check in add_stmt would then be unnecessary, as we'd always be assured of having someplace in the stack to store it. I don't trust myself to write a patch like that tonight; I'll twiddle with that tomorrow. As to the NULL checking in append_to_statement_list_1, I was being hasty and naive. There are scores of places throughout the compiler that depend on this behavior; I don't think it's worthwhile to change all the callers to ensure the pointer-to-statement_list points to a non-NULL thing. -Nathan
