arch/noarch/util/noarch_backend.ml

   1 (*
   2  * This is the generic backend modules.
   3  *
   4  * ----------------------------------------------------------------
   5  *
   6  * @begin[license]
   7  * Copyright (C) 2002 Justin David Smith, Caltech
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version 2
  12  * of the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  *
  23  * Author: Jason Hickey
  24  * @email{jyh@cs.caltech.edu}
  25  * @end[license]
  26  *)
  27
  28 open Symbol
  29 open Frame_type
  30
  31
  32 (*
  33  * WARNING:  The values in here are nonsensical.
  34  *           Do not use them as real backend values.
  35  *)
  36
  37
  38 let null_symbol = new_symbol_string "null"
  39 let fail_miserably _ = raise (Failure "Noarch_backend: cannot compile to assembly")
  40
  41
  42 module Backend : BackendSig =
  43 struct
  44    (* Type of an assembly block *)
  45    type block = unit
  46
  47    (* Pointer table descriptors *)
  48    let pointer_base = null_symbol
  49    let pointer_size = null_symbol
  50
  51    (* Closure table descriptors *)
  52    let function_base = null_symbol
  53    let function_size = null_symbol
  54
  55    (* Segmentation faults *)
  56    let other_fault = 0
  57    let index_fault = 0
  58    let fun_index_fault = 0
  59    let fun_arity_tag_fault = 0
  60    let pointer_index_fault = 0
  61    let bounds_fault = 0
  62    let lower_bounds_fault = 0
  63    let upper_bounds_fault = 0
  64    let null_pointer_fault = 0
  65    let fault_count = 0
  66    let seg_fault_labels = [||]
  67
  68    (* Debug labels *)
  69    let debug_alloc = 0
  70    let debug_let_poly = 0
  71    let debug_let_pointer = 0
  72    let debug_let_function = 0
  73    let debug_set_poly = 0
  74    let debug_set_pointer = 0
  75    let debug_set_function = 0
  76    let debug_pre_let_poly = 0
  77    let debug_pre_let_pointer = 0
  78    let debug_pre_let_function = 0
  79    let debug_pre_set_pointer = 0
  80    let debug_pre_set_function = 0
  81    let debug_count = 0
  82    let debug_labels = [||]
  83
  84    (* Hash value for pointer entries *)
  85    let hash_index_label = null_symbol
  86    let hash_fun_index_label = null_symbol
  87    let index_shift32 = Int32.zero
  88
  89    (* Pointer table masks *)
  90    let ptable_pointer_mask = Int32.zero
  91    let ptable_valid_bit_off = 0
  92
  93    (* Size constants *)
  94    let aggr_header_size = 0
  95    let block_header_size = 0
  96
  97    (* Special tags *)
  98    let rttd_tag = 0
  99
 100    (* Migration values *)
 101    let migrate_debug_gdbhooks = Int32.zero
 102
 103    (* Arity tags *)
 104    let backend_arity_tags = []
 105 end
 106
 107
 108 (*
 109  * The abstract frame.
 110  *)
 111 module Frame =
 112 struct
 113    type 'a block = unit
 114    type spset = unit
 115    type reg_class = int
 116    type inst = unit
 117
 118    let def_cost = 0
 119    let use_cost = 0
 120    let mov_def_cost = 0
 121    let mov_use_cost = 0
 122
 123    let block_label = fail_miserably
 124    let block_code = fail_miserably
 125    let block_live = fail_miserably
 126    let print_blocks = fail_miserably
 127    let print_live_blocks = fail_miserably
 128
 129    let reg_class_count = 0
 130    let registers = [||]
 131    let registers_special = [||]
 132
 133    let spset_spill = fail_miserably
 134    let spset_add = fail_miserably
 135
 136    let subst_blocks = fail_miserably
 137
 138    let vars_blocks = fail_miserably
 139 end