find/util.c

   1 /* util.c -- functions for initializing new tree elements, and other things.
   2    Copyright (C) 1990, 91, 92, 93, 94, 2000 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 9 Temple Place - Suite 330, Boston, MA 02111-1307,
  17    USA.
  18 */
  19
  20 #include "defs.h"
  21
  22 #if ENABLE_NLS
  23 # include <libintl.h>
  24 # define _(Text) gettext (Text)
  25 #else
  26 # define _(Text) Text
  27 #endif
  28 #ifdef gettext_noop
  29 # define N_(String) gettext_noop (String)
  30 #else
  31 # define N_(String) (String)
  32 #endif
  33
  34 \f
  35 /* Return a pointer to a new predicate structure, which has been
  36    linked in as the last one in the predicates list.
  37
  38    Set `predicates' to point to the start of the predicates list.
  39    Set `last_pred' to point to the new last predicate in the list.
  40
  41    Set all cells in the new structure to the default values. */
  42
  43 struct predicate *
  44 get_new_pred (void)
  45 {
  46   register struct predicate *new_pred;
  47
  48   if (predicates == NULL)
  49     {
  50       predicates = (struct predicate *)
  51         xmalloc (sizeof (struct predicate));
  52       last_pred = predicates;
  53     }
  54   else
  55     {
  56       new_pred = (struct predicate *) xmalloc (sizeof (struct predicate));
  57       last_pred->pred_next = new_pred;
  58       last_pred = new_pred;
  59     }
  60   last_pred->pred_func = NULL;
  61 #ifdef  DEBUG
  62   last_pred->p_name = NULL;
  63 #endif  /* DEBUG */
  64   last_pred->p_type = NO_TYPE;
  65   last_pred->p_prec = NO_PREC;
  66   last_pred->side_effects = false;
  67   last_pred->no_default_print = false;
  68   last_pred->need_stat = true;
  69   last_pred->args.str = NULL;
  70   last_pred->pred_next = NULL;
  71   last_pred->pred_left = NULL;
  72   last_pred->pred_right = NULL;
  73   return (last_pred);
  74 }
  75 \f
  76 /* Return a pointer to a new predicate, with operator check.
  77    Like get_new_pred, but it checks to make sure that the previous
  78    predicate is an operator.  If it isn't, the AND operator is inserted. */
  79
  80 struct predicate *
  81 get_new_pred_chk_op (void)
  82 {
  83   struct predicate *new_pred;
  84
  85   if (last_pred)
  86     switch (last_pred->p_type)
  87       {
  88       case NO_TYPE:
  89         error (1, 0, _("oops -- invalid default insertion of and!"));
  90         break;
  91
  92       case PRIMARY_TYPE:
  93       case CLOSE_PAREN:
  94         new_pred = get_new_pred ();
  95         new_pred->pred_func = pred_and;
  96 #ifdef  DEBUG
  97         new_pred->p_name = find_pred_name (pred_and);
  98 #endif  /* DEBUG */
  99         new_pred->p_type = BI_OP;
 100         new_pred->p_prec = AND_PREC;
 101         new_pred->need_stat = false;
 102         new_pred->args.str = NULL;
 103
 104       default:
 105         break;
 106       }
 107   return (get_new_pred ());
 108 }
 109 \f
 110 /* Add a primary of predicate type PRED_FUNC to the predicate input list.
 111
 112    Return a pointer to the predicate node just inserted.
 113
 114    Fills in the following cells of the new predicate node:
 115
 116    pred_func        PRED_FUNC
 117    args(.str)       NULL
 118    p_type           PRIMARY_TYPE
 119    p_prec           NO_PREC
 120
 121    Other cells that need to be filled in are defaulted by
 122    get_new_pred_chk_op, which is used to insure that the prior node is
 123    either not there at all (we are the very first node) or is an
 124    operator. */
 125
 126 struct predicate *
 127 insert_primary (boolean (*pred_func) (/* ??? */))
 128 {
 129   struct predicate *new_pred;
 130
 131   new_pred = get_new_pred_chk_op ();
 132   new_pred->pred_func = pred_func;
 133 #ifdef  DEBUG
 134   new_pred->p_name = find_pred_name (pred_func);
 135 #endif  /* DEBUG */
 136   new_pred->args.str = NULL;
 137   new_pred->p_type = PRIMARY_TYPE;
 138   new_pred->p_prec = NO_PREC;
 139   return (new_pred);
 140 }
 141 \f
 142 void
 143 usage (char *msg)
 144 {
 145   if (msg)
 146     fprintf (stderr, "%s: %s\n", program_name, msg);
 147   fprintf (stderr, _("\
 148 Usage: %s [path...] [expression]\n"), program_name);
 149   exit (1);
 150 }