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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 #include "defs.h"
  19
  20 #if ENABLE_NLS
  21 # include <libintl.h>
  22 # define _(Text) gettext (Text)
  23 #else
  24 # define _(Text) Text
  25 #endif
  26 #ifdef gettext_noop
  27 # define N_(String) gettext_noop (String)
  28 #else
  29 # define N_(String) (String)
  30 #endif
  31
  32 \f
  33 /* Return a pointer to a new predicate structure, which has been
  34    linked in as the last one in the predicates list.
  35
  36    Set `predicates' to point to the start of the predicates list.
  37    Set `last_pred' to point to the new last predicate in the list.
  38
  39    Set all cells in the new structure to the default values. */
  40
  41 struct predicate *
  42 get_new_pred (void)
  43 {
  44   register struct predicate *new_pred;
  45
  46   if (predicates == NULL)
  47     {
  48       predicates = (struct predicate *)
  49         xmalloc (sizeof (struct predicate));
  50       last_pred = predicates;
  51     }
  52   else
  53     {
  54       new_pred = (struct predicate *) xmalloc (sizeof (struct predicate));
  55       last_pred->pred_next = new_pred;
  56       last_pred = new_pred;
  57     }
  58   last_pred->pred_func = NULL;
  59 #ifdef  DEBUG
  60   last_pred->p_name = NULL;
  61 #endif  /* DEBUG */
  62   last_pred->p_type = NO_TYPE;
  63   last_pred->p_prec = NO_PREC;
  64   last_pred->side_effects = false;
  65   last_pred->need_stat = true;
  66   last_pred->args.str = NULL;
  67   last_pred->pred_next = NULL;
  68   last_pred->pred_left = NULL;
  69   last_pred->pred_right = NULL;
  70   return (last_pred);
  71 }
  72 \f
  73 /* Return a pointer to a new predicate, with operator check.
  74    Like get_new_pred, but it checks to make sure that the previous
  75    predicate is an operator.  If it isn't, the AND operator is inserted. */
  76
  77 struct predicate *
  78 get_new_pred_chk_op (void)
  79 {
  80   struct predicate *new_pred;
  81
  82   if (last_pred)
  83     switch (last_pred->p_type)
  84       {
  85       case NO_TYPE:
  86         error (1, 0, _("oops -- invalid default insertion of and!"));
  87         break;
  88
  89       case PRIMARY_TYPE:
  90       case CLOSE_PAREN:
  91         new_pred = get_new_pred ();
  92         new_pred->pred_func = pred_and;
  93 #ifdef  DEBUG
  94         new_pred->p_name = find_pred_name (pred_and);
  95 #endif  /* DEBUG */
  96         new_pred->p_type = BI_OP;
  97         new_pred->p_prec = AND_PREC;
  98         new_pred->need_stat = false;
  99         new_pred->args.str = NULL;
 100
 101       default:
 102         break;
 103       }
 104   return (get_new_pred ());
 105 }
 106 \f
 107 /* Add a primary of predicate type PRED_FUNC to the predicate input list.
 108
 109    Return a pointer to the predicate node just inserted.
 110
 111    Fills in the following cells of the new predicate node:
 112
 113    pred_func        PRED_FUNC
 114    args(.str)       NULL
 115    p_type           PRIMARY_TYPE
 116    p_prec           NO_PREC
 117
 118    Other cells that need to be filled in are defaulted by
 119    get_new_pred_chk_op, which is used to insure that the prior node is
 120    either not there at all (we are the very first node) or is an
 121    operator. */
 122
 123 struct predicate *
 124 insert_primary (boolean (*pred_func) (/* ??? */))
 125 {
 126   struct predicate *new_pred;
 127
 128   new_pred = get_new_pred_chk_op ();
 129   new_pred->pred_func = pred_func;
 130 #ifdef  DEBUG
 131   new_pred->p_name = find_pred_name (pred_func);
 132 #endif  /* DEBUG */
 133   new_pred->args.str = NULL;
 134   new_pred->p_type = PRIMARY_TYPE;
 135   new_pred->p_prec = NO_PREC;
 136   return (new_pred);
 137 }
 138 \f
 139 void
 140 usage (char *msg)
 141 {
 142   if (msg)
 143     fprintf (stderr, "%s: %s\n", program_name, msg);
 144   fprintf (stderr, _("\
 145 Usage: %s [path...] [expression]\n"), program_name);
 146   exit (1);
 147 }