Patch for GDB top of trunk

[Nat Gurumoorthy <nat dot gurumoorthy at ubicom dot com>]

Description of the bugs:
	In mi-main.c there are places where
"mi_cmd_data_list_register_values" returns MI_CMD_ERROR.
At each of those places ui_out_tuple_end needs to be called
to balance calls to ui_out_tuple_begin.

	In mi-cmd-disas.c in the function "mi_cmd_disassemble"
there is for loop which converts le entries to mle entries. The
mle[i].end_pc is created by
mld[i].end_pc = le[i+1].pc. There will be cases where 
end_pc >= high and hence has to wrong address for the last line
of a function. We need to clamp by calling find_pc_line and letting
it figure out the end_pc for this line and copying it in place.

	Further down in the same funtion there is a for loop to print
each assembly line for mixed mode printing. You enter the for
loop file filename = NULL and name = NULL. 
build_address_symbolic is called and it may or may not allocate
memory for filename and name. xfree routine is called to free this
allocated memory if filename or name != NULL. These pointers
need to be set to NULL before you go through the loop one more time.
If build_address_symbolic fails to allocate memory xfree will get
called with stale pointers.

Regards
Nat.

PS. I do not have test cases. I ran into these while chasing GDB
crashes in Rehat's UBICOM ip2k port of GDB. I then looked up
to see if the main GDB trunk had these problems and hence
this patch.


Changelog entry
2001-06-11 Nat Gurumoorthy <nat.gurumoorthy@ubicom.com>

	* mi-main.c (mi_cmd_data_list_changed_registers,
	mi_cmd_data_list_register_values: Ensure
	ui_out_tuple_end gets called enough number of times before 
	return MI_CMD_ERROR happens.
	
	* mi-cmd-disas.c (mi_cmd_disassemble): Make sure "filename"
	and "name" pointers get set to NULL after call to xfree. This
	is to prevent calls to xfree with stale pointers if call to
	build_address_symbolic fails to allocate memory for either
	of these.
	(mi_cmd_disassemble): Clamp end_pc for a mle entry if 
	end_pc is >= high. GDB will face this issue if a file has
	code from different sections and the addresses of the sections
	scrambles the line number ordering.


Patch


Index: gdb/mi/mi-cmd-disas.c
===================================================================
RCS file: /cvs/src/src/gdb/mi/mi-cmd-disas.c,v
retrieving revision 1.10
diff -c -3 -p -r1.10 mi-cmd-disas.c
*** mi-cmd-disas.c	2001/05/12 04:08:24	1.10
--- mi-cmd-disas.c	2001/06/12 02:49:26
*************** mi_cmd_disassemble (char *command, char 
*** 337,342 ****
--- 337,349 ----
  	    out_of_order = 1;
  	  mle[newlines].start_pc = le[i].pc;
  	  mle[newlines].end_pc = le[i + 1].pc;
+ 
+ 	  /* check if end_pc is >= high and clamp it */
+ 	  if(mle[newlines].end_pc >= high)
+ 	    {
+ 	      sal = find_pc_line (le[i].pc, 0);
+ 	      mle[newlines].end_pc = sal.end;
+ 	    }
  	  newlines++;
  	}
  
*************** mi_cmd_disassemble (char *command, char 
*** 429,437 ****
  		  ui_out_field_int (uiout, "offset", offset);
  		}
  	      if (filename != NULL)
! 		xfree (filename);
  	      if (name != NULL)
! 		xfree (name);
  
  	      ui_file_rewind (stb->stream);
  	      pc += (*tm_print_insn) (pc, &di);
--- 436,450 ----
  		  ui_out_field_int (uiout, "offset", offset);
  		}
  	      if (filename != NULL)
! 		{
! 		  xfree (filename);
! 		  filename = NULL;
! 		}
  	      if (name != NULL)
! 		{
! 		  xfree (name);
! 		  name = NULL;
! 		}
  
  	      ui_file_rewind (stb->stream);
  	      pc += (*tm_print_insn) (pc, &di);
Index: gdb/mi/mi-main.c
===================================================================
RCS file: /cvs/src/src/gdb/mi/mi-main.c,v
retrieving revision 1.14
diff -c -3 -p -r1.14 mi-main.c
*** mi-main.c	2001/05/12 04:08:24	1.14
--- mi-main.c	2001/06/12 02:49:27
*************** mi_cmd_data_list_changed_registers (char
*** 339,344 ****
--- 339,345 ----
  	    {
  	      xasprintf (&mi_error_message,
  			 "mi_cmd_data_list_changed_registers: Unable to read
register contents.");
+ 	      ui_out_tuple_end (uiout);
  	      return MI_CMD_ERROR;
  	    }
  	  else if (changed)
*************** mi_cmd_data_list_changed_registers (char
*** 361,366 ****
--- 362,368 ----
  	    {
  	      xasprintf (&mi_error_message,
  			 "mi_cmd_data_list_register_change: Unable to read
register contents.");
+ 	      ui_out_tuple_end (uiout);
  	      return MI_CMD_ERROR;
  	    }
  	  else if (changed)
*************** mi_cmd_data_list_changed_registers (char
*** 369,374 ****
--- 371,377 ----
        else
  	{
  	  xasprintf (&mi_error_message, "bad register number");
+ 	  ui_out_tuple_end (uiout);
  	  return MI_CMD_ERROR;
  	}
      }
*************** mi_cmd_data_list_register_values (char *
*** 447,455 ****
  	  ui_out_tuple_begin (uiout, NULL);
  	  ui_out_field_int (uiout, "number", regnum);
  	  result = get_register (regnum, format);
- 	  if (result == -1)
- 	    return MI_CMD_ERROR;
  	  ui_out_tuple_end (uiout);
  	}
      }
  
--- 450,461 ----
  	  ui_out_tuple_begin (uiout, NULL);
  	  ui_out_field_int (uiout, "number", regnum);
  	  result = get_register (regnum, format);
  	  ui_out_tuple_end (uiout);
+ 	  if (result == -1)
+ 	    {
+ 	      ui_out_tuple_end (uiout);
+ 	      return MI_CMD_ERROR;
+ 	    }
  	}
      }
  
*************** mi_cmd_data_list_register_values (char *
*** 466,478 ****
  	  ui_out_tuple_begin (uiout, NULL);
  	  ui_out_field_int (uiout, "number", regnum);
  	  result = get_register (regnum, format);
- 	  if (result == -1)
- 	    return MI_CMD_ERROR;
  	  ui_out_tuple_end (uiout);
  	}
        else
  	{
  	  xasprintf (&mi_error_message, "bad register number");
  	  return MI_CMD_ERROR;
  	}
      }
--- 472,488 ----
  	  ui_out_tuple_begin (uiout, NULL);
  	  ui_out_field_int (uiout, "number", regnum);
  	  result = get_register (regnum, format);
  	  ui_out_tuple_end (uiout);
+ 	  if (result == -1)
+ 	    {
+ 	      ui_out_tuple_end (uiout);
+ 	      return MI_CMD_ERROR;
+ 	    }
  	}
        else
  	{
  	  xasprintf (&mi_error_message, "bad register number");
+ 	  ui_out_tuple_end (uiout);
  	  return MI_CMD_ERROR;
  	}
      }