Re: [Simulavr-devel] Problem with gdb (not simulavr) (disassemble)

[Tak Auyeung]

Attached is a patch file for the suggested changes. Apply the patch when 
you are in the gdb subdirectory.

--Tak

Tak Auyeung wrote:

> Re: disassemble doesn't work because gdb grabs SRAM contents instead 
> of flash contents
>
> I have a solution to this problem now:
>
> patch gdb/values.c:
> clone the function value_as_pointer as value_as_cpointer, change 
> builtin_type_void_data_ptr to builtin_type_void_func_ptr in the clone.
>
> patch gdb/value.h:
> clone the declaration of value_as_pointer as value_as_cpointer in 
> value.h.
> clone the declaration of parse_and_eval_address as 
> parse_and_eval_caddress in value.h.
>
> patch gdb/eval.c:
> clone the function parse_and_eval_address as parse_and_eval_caddress, 
> change value_as_pointer to value_as_cpointer in the clone.
>
> patch gdb/printcmd.c:
> change parse_and_eval_address to parse_and_eval_caddress in function 
> disassemble_command
>
> The key is to cast code address as builtin_type_void_func_ptr instead 
> of builtin_type_void_data_ptr. This enables the pointer_to_address 
> function in avr_tdep.c to handle the SRAM flag properly.
>
> Ted, do you want to integrate this into your gdb patch? Since these 
> changes only affect disassembly, they should present very minimal (if 
> any!) impact to the rest of gdb functionality. Anyway, let me know if 
> this patch will be integrated, thanks!
>
> --Tak
>
> Tak Auyeung wrote:
>
> > I have done some digging and found the problem was with 
> > avr_pointer_to_address in gdb/avr-tdep.c. Currently, it only takes 
> > TYPE_CODE_FUNC and TYPE_CODE_METHOD to translate to code space, 
> > everything else gets translated to SRAM space.
> >
> > Turns out when gdb disassembles, the pointers to be translated to 
> > addresses are of TYPE_CODE_VOID. A quick hack to add the acceptance 
> > of TYPE_CODE_VOID as part of code space confirmed this.
> >
> > Now I'll check where gdb constructs the pointers for disassembly and 
> > see if I can fix it there...
> >
> > --Tak
>
>
>
>
>
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> Simulavr-devel mailing list
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*** old_printcmd.c      Tue Jan  1 16:56:07 2002
--- printcmd.c  Tue Jan  1 17:55:07 2002
*************** disassemble_command (char *arg, int from
*** 2368,2375 ****
      {
        /* Two arguments.  */
        *space_index = '\0';
!       low = parse_and_eval_address (arg);
!       high = parse_and_eval_address (space_index + 1);
      }
  
  #if defined(TUI)
--- 2368,2375 ----
      {
        /* Two arguments.  */
        *space_index = '\0';
!       low = parse_and_eval_caddress (arg);
!       high = parse_and_eval_caddress (space_index + 1);
      }
  
  #if defined(TUI)
*** old_eval.c  Tue Jan  1 16:44:18 2002
--- eval.c      Tue Jan  1 16:45:24 2002
*************** parse_and_eval_address (char *exp)
*** 85,90 ****
--- 85,103 ----
    return addr;
  }
  
+ CORE_ADDR
+ parse_and_eval_caddress(char *exp)
+ {
+   struct expression *expr = parse_expression (exp);
+   register CORE_ADDR addr;
+   register struct cleanup *old_chain =
+   make_cleanup (free_current_contents, &expr);
+ 
+   addr = value_as_cpointer (evaluate_expression (expr));
+   do_cleanups (old_chain);
+   return addr;
+ }
+ 
  /* Like parse_and_eval_address but takes a pointer to a char * variable
     and advanced that variable across the characters parsed.  */
  
*** old_values.c        Tue Jan  1 16:45:30 2002
--- values.c    Tue Jan  1 17:59:46 2002
*************** value_as_pointer (value_ptr val)
*** 603,608 ****
--- 603,622 ----
    return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val));
  #endif
  }
+ 
+ CORE_ADDR
+ value_as_cpointer (value_ptr val)
+ {
+   COERCE_ARRAY (val);
+       /* TA: force type to function */
+   if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_INT
+       && (TYPE_LENGTH (VALUE_TYPE (val))
+         <= TYPE_LENGTH (builtin_type_void_func_ptr)))
+     {
+       val = value_cast (builtin_type_void_func_ptr, val);
+     }
+   return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val));
+ }
  
  /* Unpack raw data (copied from debugee, target byte order) at VALADDR
     as a long, or as a double, assuming the raw data is described
*** old_value.h Tue Jan  1 16:54:59 2002
--- value.h     Tue Jan  1 16:55:45 2002
*************** extern DOUBLEST value_as_double (value_p
*** 289,294 ****
--- 289,296 ----
  
  extern CORE_ADDR value_as_pointer (value_ptr val);
  
+ extern CORE_ADDR value_as_cpointer (value_ptr val);
+ 
  extern LONGEST unpack_long (struct type *type, char *valaddr);
  
  extern DOUBLEST unpack_double (struct type *type, char *valaddr, int *invp);
*************** extern value_ptr parse_to_comma_and_eval
*** 434,439 ****
--- 436,443 ----
  extern struct type *parse_and_eval_type (char *p, int length);
  
  extern CORE_ADDR parse_and_eval_address (char *exp);
+ 
+ extern CORE_ADDR parse_and_eval_caddress (char *exp);
  
  extern CORE_ADDR parse_and_eval_address_1 (char **expptr);