Re: [RFC v2 38/38] convert to_get_unwinder and to_get_tailcall_unwinder to methods

[Pedro Alves <palves@redhat.com>]

Looks fine.

On 02/06/2014 08:55 PM, Tom Tromey wrote:
> This converts to_get_unwinder and to_get_tailcall_unwinder to methods
> and arranges for them to use the new delegation scheme.
> 
> This just lets us avoid having a differing style (neither new-style
> nor INHERIT) of delegation in the tree.
> 
> 2014-02-06  Tom Tromey  <tromey@redhat.com>
> 
> 	* target.c (target_get_unwinder): Rewrite.
> 	(target_get_tailcall_unwinder): Rewrite.
> 	* record-btrace.c (record_btrace_to_get_unwinder): New function.
> 	(record_btrace_to_get_tailcall_unwinder): New function.
> 	(init_record_btrace_ops): Update.
> 	* target.h (struct target_ops) <to_get_unwinder,
> 	to_get_tailcall_unwinder>: Now function pointers.  Use
> 	TARGET_DEFAULT_RETURN.
> ---
>  gdb/ChangeLog          | 11 +++++++++++
>  gdb/record-btrace.c    | 20 ++++++++++++++++++--
>  gdb/target-delegates.c | 32 ++++++++++++++++++++++++++++++++
>  gdb/target.c           | 16 ++--------------
>  gdb/target.h           | 12 ++++++++----
>  5 files changed, 71 insertions(+), 20 deletions(-)
> 
> diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c
> index c4872eb..ab288ef 100644
> --- a/gdb/record-btrace.c
> +++ b/gdb/record-btrace.c
> @@ -1302,6 +1302,22 @@ const struct frame_unwind record_btrace_tailcall_frame_unwind =
>    record_btrace_frame_dealloc_cache
>  };
>  
> +/* Implement the to_get_unwinder method.  */
> +
> +static const struct frame_unwind *
> +record_btrace_to_get_unwinder (struct target_ops *self)
> +{
> +  return &record_btrace_frame_unwind;
> +}
> +
> +/* Implement the to_get_tailcall_unwinder method.  */
> +
> +static const struct frame_unwind *
> +record_btrace_to_get_tailcall_unwinder (struct target_ops *self)
> +{
> +  return &record_btrace_tailcall_frame_unwind;
> +}
> +
>  /* Indicate that TP should be resumed according to FLAG.  */
>  
>  static void
> @@ -1888,8 +1904,8 @@ init_record_btrace_ops (void)
>    ops->to_fetch_registers = record_btrace_fetch_registers;
>    ops->to_store_registers = record_btrace_store_registers;
>    ops->to_prepare_to_store = record_btrace_prepare_to_store;
> -  ops->to_get_unwinder = &record_btrace_frame_unwind;
> -  ops->to_get_tailcall_unwinder = &record_btrace_tailcall_frame_unwind;
> +  ops->to_get_unwinder = &record_btrace_to_get_unwinder;
> +  ops->to_get_tailcall_unwinder = &record_btrace_to_get_tailcall_unwinder;
>    ops->to_resume = record_btrace_resume;
>    ops->to_wait = record_btrace_wait;
>    ops->to_find_new_threads = record_btrace_find_new_threads;
> diff --git a/gdb/target-delegates.c b/gdb/target-delegates.c
> index d9c68cd..03b0d2a 100644
> --- a/gdb/target-delegates.c
> +++ b/gdb/target-delegates.c
> @@ -1572,6 +1572,32 @@ tdefault_augmented_libraries_svr4_read (struct target_ops *self)
>    return 0;
>  }
>  
> +static const struct frame_unwind *
> +delegate_get_unwinder (struct target_ops *self)
> +{
> +  self = self->beneath;
> +  return self->to_get_unwinder (self);
> +}
> +
> +static const struct frame_unwind *
> +tdefault_get_unwinder (struct target_ops *self)
> +{
> +  return NULL;
> +}
> +
> +static const struct frame_unwind *
> +delegate_get_tailcall_unwinder (struct target_ops *self)
> +{
> +  self = self->beneath;
> +  return self->to_get_tailcall_unwinder (self);
> +}
> +
> +static const struct frame_unwind *
> +tdefault_get_tailcall_unwinder (struct target_ops *self)
> +{
> +  return NULL;
> +}
> +
>  static CORE_ADDR
>  delegate_decr_pc_after_break (struct target_ops *self, struct gdbarch *arg1)
>  {
> @@ -1844,6 +1870,10 @@ install_delegators (struct target_ops *ops)
>      ops->to_call_history_range = delegate_call_history_range;
>    if (ops->to_augmented_libraries_svr4_read == NULL)
>      ops->to_augmented_libraries_svr4_read = delegate_augmented_libraries_svr4_read;
> +  if (ops->to_get_unwinder == NULL)
> +    ops->to_get_unwinder = delegate_get_unwinder;
> +  if (ops->to_get_tailcall_unwinder == NULL)
> +    ops->to_get_tailcall_unwinder = delegate_get_tailcall_unwinder;
>    if (ops->to_decr_pc_after_break == NULL)
>      ops->to_decr_pc_after_break = delegate_decr_pc_after_break;
>  }
> @@ -1982,5 +2012,7 @@ install_dummy_methods (struct target_ops *ops)
>    ops->to_call_history_from = tdefault_call_history_from;
>    ops->to_call_history_range = tdefault_call_history_range;
>    ops->to_augmented_libraries_svr4_read = tdefault_augmented_libraries_svr4_read;
> +  ops->to_get_unwinder = tdefault_get_unwinder;
> +  ops->to_get_tailcall_unwinder = tdefault_get_tailcall_unwinder;
>    ops->to_decr_pc_after_break = default_target_decr_pc_after_break;
>  }
> diff --git a/gdb/target.c b/gdb/target.c
> index 72d5a09..d03c4fb 100644
> --- a/gdb/target.c
> +++ b/gdb/target.c
> @@ -3761,13 +3761,7 @@ debug_to_prepare_to_store (struct target_ops *self, struct regcache *regcache)
>  const struct frame_unwind *
>  target_get_unwinder (void)
>  {
> -  struct target_ops *t;
> -
> -  for (t = current_target.beneath; t != NULL; t = t->beneath)
> -    if (t->to_get_unwinder != NULL)
> -      return t->to_get_unwinder;
> -
> -  return NULL;
> +  return current_target.to_get_unwinder (&current_target);
>  }
>  
>  /* See target.h.  */
> @@ -3775,13 +3769,7 @@ target_get_unwinder (void)
>  const struct frame_unwind *
>  target_get_tailcall_unwinder (void)
>  {
> -  struct target_ops *t;
> -
> -  for (t = current_target.beneath; t != NULL; t = t->beneath)
> -    if (t->to_get_tailcall_unwinder != NULL)
> -      return t->to_get_tailcall_unwinder;
> -
> -  return NULL;
> +  return current_target.to_get_tailcall_unwinder (&current_target);
>  }
>  
>  /* Default implementation of to_decr_pc_after_break.  */
> diff --git a/gdb/target.h b/gdb/target.h
> index c988a01..58519b0 100644
> --- a/gdb/target.h
> +++ b/gdb/target.h
> @@ -1095,10 +1095,14 @@ struct target_ops
>      int (*to_augmented_libraries_svr4_read) (struct target_ops *)
>        TARGET_DEFAULT_RETURN (0);
>  
> -    /* Those unwinders are tried before any other arch unwinders.  Use NULL if
> -       it is not used.  */
> -    const struct frame_unwind *to_get_unwinder;
> -    const struct frame_unwind *to_get_tailcall_unwinder;
> +    /* Those unwinders are tried before any other arch unwinders.  If
> +       SELF doesn't have unwinders, it should delegate to the
> +       "beneath" target.  */
> +    const struct frame_unwind *(*to_get_unwinder) (struct target_ops *self)
> +      TARGET_DEFAULT_RETURN (NULL);
> +
> +    const struct frame_unwind *(*to_get_tailcall_unwinder) (struct target_ops *self)
> +      TARGET_DEFAULT_RETURN (NULL);
>  
>      /* Return the number of bytes by which the PC needs to be decremented
>         after executing a breakpoint instruction.
> 


-- 
Pedro Alves