RFA: Reliably restore result_ptr in gdbtk_load_asm

[Jim Blandy <jimb at zwingli dot cygnus dot com>]

2000-04-01  Jim Blandy  <jimb@redhat.com>

	* gdbtk-hooks.c (gdbtk_restore_result_ptr): New function.
	* gdbtk.h (gdbtk_restore_result_ptr): Declare it.
	* gdbtk-cmds.c (gdbtk_load_asm): Use it to restore the old value
	of result_ptr, in case we get errors while disassembling things.

Index: gdb/gdbtk/generic/gdbtk-cmds.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbtk/generic/gdbtk-cmds.c,v
retrieving revision 1.5
diff -c -r1.5 gdbtk-cmds.c
*** gdb/gdbtk/generic/gdbtk-cmds.c	2000/03/28 23:04:02	1.5
--- gdb/gdbtk/generic/gdbtk-cmds.c	2000/04/01 23:19:21
***************
*** 2751,2756 ****
--- 2751,2757 ----
  
  }
  
+ 
  static CORE_ADDR
  gdbtk_load_asm (clientData, pc, di)
       ClientData clientData;
***************
*** 2761,2767 ****
      = (struct disassembly_client_data *) clientData;
    char **text_argv;
    int i, pc_to_line_len, line_to_pc_len;
!   gdbtk_result new_result, *old_result_ptr;
  
    pc_to_line_len = Tcl_DStringLength (&client_data->pc_to_line_prefix);
    line_to_pc_len = Tcl_DStringLength (&client_data->line_to_pc_prefix);
--- 2762,2769 ----
      = (struct disassembly_client_data *) clientData;
    char **text_argv;
    int i, pc_to_line_len, line_to_pc_len;
!   gdbtk_result new_result;
!   struct cleanup *old_chain = NULL;
  
    pc_to_line_len = Tcl_DStringLength (&client_data->pc_to_line_prefix);
    line_to_pc_len = Tcl_DStringLength (&client_data->line_to_pc_prefix);
***************
*** 2771,2777 ****
    /* Preserve the current Tcl result object, print out what we need, and then
       suck it out of the result, and replace... */
  
!   old_result_ptr = result_ptr;
    result_ptr = &new_result;
    result_ptr->obj_ptr = client_data->result_obj[0];
    result_ptr->flags = GDBTK_TO_RESULT;
--- 2773,2779 ----
    /* Preserve the current Tcl result object, print out what we need, and then
       suck it out of the result, and replace... */
  
!   old_chain = make_cleanup (gdbtk_restore_result_ptr, (void *) result_ptr);
    result_ptr = &new_result;
    result_ptr->obj_ptr = client_data->result_obj[0];
    result_ptr->flags = GDBTK_TO_RESULT;
***************
*** 2833,2839 ****
        
      }
    
!   result_ptr = old_result_ptr;
      
    return pc;
  }
--- 2835,2841 ----
        
      }
    
!   do_cleanups (old_chain);
      
    return pc;
  }
Index: gdb/gdbtk/generic/gdbtk-hooks.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbtk/generic/gdbtk-hooks.c,v
retrieving revision 1.2
diff -c -r1.2 gdbtk-hooks.c
*** gdb/gdbtk/generic/gdbtk-hooks.c	2000/02/24 03:11:47	1.2
--- gdb/gdbtk/generic/gdbtk-hooks.c	2000/04/01 23:19:21
***************
*** 183,188 ****
--- 183,198 ----
   */
  
  gdbtk_result *result_ptr = NULL;
+ 
+ /* If you want to restore an old value of result_ptr whenever cleanups
+    are run, pass this function to make_cleanup, along with the value
+    of result_ptr you'd like to reinstate.  */
+ void
+ gdbtk_restore_result_ptr (void *old_result_ptr)
+ {
+   result_ptr = (gdbtk_result *) old_result_ptr;
+ }
+ 
  
  
  /* This allows you to Tcl_Eval a tcl command which takes
Index: gdb/gdbtk/generic/gdbtk.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbtk/generic/gdbtk.h,v
retrieving revision 1.1.1.1
diff -c -r1.1.1.1 gdbtk.h
*** gdb/gdbtk/generic/gdbtk.h	2000/02/07 00:19:42	1.1.1.1
--- gdb/gdbtk/generic/gdbtk.h	2000/04/01 23:19:21
***************
*** 133,138 ****
--- 133,143 ----
  
  extern gdbtk_result *result_ptr;
  
+ /* If you want to restore an old value of result_ptr whenever cleanups
+    are run, pass this function to make_cleanup, along with the value
+    of result_ptr you'd like to reinstate.  */
+ extern void gdbtk_restore_result_ptr (void *);
+ 
  /* GDB context identifier */
  extern int gdb_context;