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., 59 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 /* See locate.c for explanation as to why not use (String) */
  32 # define N_(String) String
  33 #endif
  34
  35 \f
  36 /* Return a pointer to a new predicate structure, which has been
  37    linked in as the last one in the predicates list.
  38
  39    Set `predicates' to point to the start of the predicates list.
  40    Set `last_pred' to point to the new last predicate in the list.
  41
  42    Set all cells in the new structure to the default values. */
  43
  44 struct predicate *
  45 get_new_pred (void)
  46 {
  47   register struct predicate *new_pred;
  48
  49   if (predicates == NULL)
  50     {
  51       predicates = (struct predicate *)
  52         xmalloc (sizeof (struct predicate));
  53       last_pred = predicates;
  54     }
  55   else
  56     {
  57       new_pred = (struct predicate *) xmalloc (sizeof (struct predicate));
  58       last_pred->pred_next = new_pred;
  59       last_pred = new_pred;
  60     }
  61   last_pred->pred_func = NULL;
  62 #ifdef  DEBUG
  63   last_pred->p_name = NULL;
  64 #endif  /* DEBUG */
  65   last_pred->p_type = NO_TYPE;
  66   last_pred->p_prec = NO_PREC;
  67   last_pred->side_effects = false;
  68   last_pred->no_default_print = false;
  69   last_pred->need_stat = true;
  70   last_pred->args.str = NULL;
  71   last_pred->pred_next = NULL;
  72   last_pred->pred_left = NULL;
  73   last_pred->pred_right = NULL;
  74   return (last_pred);
  75 }
  76 \f
  77 /* Return a pointer to a new predicate, with operator check.
  78    Like get_new_pred, but it checks to make sure that the previous
  79    predicate is an operator.  If it isn't, the AND operator is inserted. */
  80
  81 struct predicate *
  82 get_new_pred_chk_op (void)
  83 {
  84   struct predicate *new_pred;
  85
  86   if (last_pred)
  87     switch (last_pred->p_type)
  88       {
  89       case NO_TYPE:
  90         error (1, 0, _("oops -- invalid default insertion of and!"));
  91         break;
  92
  93       case PRIMARY_TYPE:
  94       case CLOSE_PAREN:
  95         new_pred = get_new_pred ();
  96         new_pred->pred_func = pred_and;
  97 #ifdef  DEBUG
  98         new_pred->p_name = find_pred_name (pred_and);
  99 #endif  /* DEBUG */
 100         new_pred->p_type = BI_OP;
 101         new_pred->p_prec = AND_PREC;
 102         new_pred->need_stat = false;
 103         new_pred->args.str = NULL;
 104
 105       default:
 106         break;
 107       }
 108   return (get_new_pred ());
 109 }
 110 \f
 111 /* Add a primary of predicate type PRED_FUNC to the predicate input list.
 112
 113    Return a pointer to the predicate node just inserted.
 114
 115    Fills in the following cells of the new predicate node:
 116
 117    pred_func        PRED_FUNC
 118    args(.str)       NULL
 119    p_type           PRIMARY_TYPE
 120    p_prec           NO_PREC
 121
 122    Other cells that need to be filled in are defaulted by
 123    get_new_pred_chk_op, which is used to insure that the prior node is
 124    either not there at all (we are the very first node) or is an
 125    operator. */
 126
 127 struct predicate *
 128 insert_primary (boolean (*pred_func) (/* ??? */))
 129 {
 130   struct predicate *new_pred;
 131
 132   new_pred = get_new_pred_chk_op ();
 133   new_pred->pred_func = pred_func;
 134 #ifdef  DEBUG
 135   new_pred->p_name = find_pred_name (pred_func);
 136 #endif  /* DEBUG */
 137   new_pred->args.str = NULL;
 138   new_pred->p_type = PRIMARY_TYPE;
 139   new_pred->p_prec = NO_PREC;
 140   return (new_pred);
 141 }
 142 \f
 143 void
 144 usage (char *msg)
 145 {
 146   if (msg)
 147     fprintf (stderr, "%s: %s\n", program_name, msg);
 148   fprintf (stderr, _("\
 149 Usage: %s [path...] [expression]\n"), program_name);
 150   exit (1);
 151 }