Re: [RFA] Resubmit process record and replay, 4/10

[Michael Snyder <msnyder@vmware.com>]

Seems like a couple of people had some doubts about this
particular part of the implementation.

Does anyone have any alternative suggestions?

teawater wrote:
> The process record and replay target has six function pointers
> record_beneath_to_resume, record_beneath_to_wait,
> record_beneath_to_prepare_to_store, record_beneath_to_xfer_partial,
> record_beneath_to_insert_breakpoint and
> record_beneath_to_remove_breakpoint.
> This patch add code to function "update_current_target" make these
> pointers always point to the function of lower strata target than
> process record and replay target.
> 
> When GDB in record mode, we need to call the really debug function in
> low strata target because process record and replay target need call
> this function to control the inferior.
> 
> Struct target_ops already has a pointer "beneath" point to low strata
> target, but process record and replay target doesn't use it.  Because
> if low strata target doesn't set some function pointers, process
> record and replay target will need to call the function pointers of
> the target that is low strata target of this target.  If this target
> doesn't set them too, it will need to call anothers.  So use "beneath"
> is not a good choice and "multi-thread" target that need function
> pointers of low strata target doesn't use "beneath" too.
> 
> 2008-11-16  Hui Zhu  <teawater@gmail.com>
> 
> 	* target.c (update_current_target): Set function points
> 	record_beneath_to_resume,
> 	record_beneath_to_wait,
> 	record_beneath_to_prepare_to_store,
> 	record_beneath_to_xfer_partial,
> 	record_beneath_to_insert_breakpoint
> 	and record_beneath_to_remove_breakpoint point to the function
> 	of target that lower than process record and replay target.
> 
>  target.c |   36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> Following is the diff with the previous patch:
> @@ -8,7 +8,7 @@
> 
>   static void target_info (char *, int);
> 
> -@@ -387,6 +388,12 @@ update_current_target (void)
> +@@ -405,6 +406,12 @@
>         if (!current_target.FIELD) \
>   	current_target.FIELD = (TARGET)->FIELD
> 
> @@ -21,12 +21,12 @@
>     for (t = target_stack; t; t = t->beneath)
>       {
>         INHERIT (to_shortname, t);
> -@@ -476,6 +483,35 @@ update_current_target (void)
> +@@ -494,6 +501,35 @@
>         /* Do not inherit to_memory_map.  */
>         /* Do not inherit to_flash_erase.  */
>         /* Do not inherit to_flash_done.  */
>  +
> -+      /* Set the real beneath function pointers. */
> ++      /* Set pointers to functions in the target beneath us.  */
>  +      if (t != &record_ops)
>  +        {
>  +           if (!record_beneath_to_resume)
> 
> 
> ------------------------------------------------------------------------
> 
> --- a/target.c
> +++ b/target.c
> @@ -41,6 +41,7 @@
>  #include "target-descriptions.h"
>  #include "gdbthread.h"
>  #include "solib.h"
> +#include "record.h"
>  
>  static void target_info (char *, int);
>  
> @@ -405,6 +406,12 @@
>        if (!current_target.FIELD) \
>  	current_target.FIELD = (TARGET)->FIELD
>  
> +  record_beneath_to_resume = NULL;
> +  record_beneath_to_store_registers = NULL;
> +  record_beneath_to_xfer_partial = NULL;
> +  record_beneath_to_insert_breakpoint = NULL;
> +  record_beneath_to_remove_breakpoint = NULL;
> +
>    for (t = target_stack; t; t = t->beneath)
>      {
>        INHERIT (to_shortname, t);
> @@ -494,6 +501,35 @@
>        /* Do not inherit to_memory_map.  */
>        /* Do not inherit to_flash_erase.  */
>        /* Do not inherit to_flash_done.  */
> +
> +      /* Set pointers to functions in the target beneath us.  */
> +      if (t != &record_ops)
> +        {
> +           if (!record_beneath_to_resume)
> +             {
> +               record_beneath_to_resume = t->to_resume;
> +             }
> +           if (!record_beneath_to_wait)
> +             {
> +               record_beneath_to_wait = t->to_wait;
> +             }
> +           if (!record_beneath_to_store_registers)
> +             {
> +               record_beneath_to_store_registers = t->to_store_registers;
> +             }
> +           if (!record_beneath_to_xfer_partial)
> +             {
> +               record_beneath_to_xfer_partial = t->to_xfer_partial;
> +             }
> +           if (!record_beneath_to_insert_breakpoint)
> +             {
> +               record_beneath_to_insert_breakpoint = t->to_insert_breakpoint;
> +             }
> +           if (!record_beneath_to_remove_breakpoint)
> +             {
> +               record_beneath_to_remove_breakpoint = t->to_remove_breakpoint;
> +             }
> +        }
>      }
>  #undef INHERIT
>