Re: [RFA 09/22] Remove make_cleanup_restore_current_ui

Simon Marchi
2016-10-01T04:29:35Z

On 2016-09-27 00:08, Tom Tromey wrote:
> --- a/gdb/top.h
> +++ b/gdb/top.h
> @@ -155,27 +155,52 @@ extern struct ui *current_ui;
> /* The list of all UIs. */
> extern struct ui *ui_list;
>
> -/* State for SWITCH_THRU_ALL_UIS. Declared here because it is meant
> - to be created on the stack, but should be treated as opaque. */
> -struct switch_thru_all_uis
> +/* State for SWITCH_THRU_ALL_UIS. */
> +class switch_thru_all_uis
> {
> +public:
> +
> + switch_thru_all_uis () : iter (nullptr), save_ui (&current_ui)

We are targetting C++98, aren't we? Or is it C++03? Either way,
nullptr appeared in C++11, so I guess we can't use it.

The fact that your compiler (and mine) did not catch this begs the
question, should we have one of -std=c++98/gnu++98/c++03/gnu++03 in our
compilation flags, instead of relying of the compiler's default mode?

> + {
> + iter = ui_list;
> + }
> +
> + ~switch_thru_all_uis ()
> + {
> + }
> +
> + // If done iterating, return true; otherwise return false.
> + bool done () const
> + {
> + return iter == nullptr;
> + }
> +
> + // Move to the next UI, setting current_ui if iteration is not yet
> + // complete.
> + void next ()
> + {
> + iter = iter->next;
> + if (iter != nullptr)
> + current_ui = iter;
> + }
> +
> + private:
> +
> + // No need for these. They are intentionally not defined anywhere.
> + switch_thru_all_uis &operator= (const switch_thru_all_uis &);
> + switch_thru_all_uis (const switch_thru_all_uis &);
> +
> + // Used to iterate through the UIs.
> struct ui *iter;
> - struct cleanup *old_chain;
> -};
>
> -/* Functions to drive SWITCH_THRU_ALL_UIS. Though declared here by
> - necessity, these functions should not be used other than via the
> - SWITCH_THRU_ALL_UIS macro defined below. */
> -extern void switch_thru_all_uis_init (struct switch_thru_all_uis
> *state);
> -extern int switch_thru_all_uis_cond (struct switch_thru_all_uis
> *state);
> -extern void switch_thru_all_uis_next (struct switch_thru_all_uis
> *state);
> + // Save and restore current_ui.
> + scoped_restore<struct ui *> save_ui;
> +};
>
> /* Traverse through all UI, and switch the current UI to the one
> being iterated. */
> #define SWITCH_THRU_ALL_UIS(STATE) \

You can remove STATE here. I am surprised the preprocessor doesn't care
about the missing argument in macro references.