usr.bin/make/lst.lib/lstInsert.c

   1 /*      $NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $       */
   2
   3 /*
   4  * Copyright (c) 1988, 1989, 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Adam de Boor.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #ifndef MAKE_NATIVE
  36 static char rcsid[] = "$NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $";
  37 #else
  38 #include <sys/cdefs.h>
  39 #ifndef lint
  40 #if 0
  41 static char sccsid[] = "@(#)lstInsert.c 8.1 (Berkeley) 6/6/93";
  42 #else
  43 __RCSID("$NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $");
  44 #endif
  45 #endif /* not lint */
  46 #endif
  47
  48 /*-
  49  * LstInsert.c --
  50  *      Insert a new datum before an old one
  51  */
  52
  53 #include        "lstInt.h"
  54
  55 /*-
  56  *-----------------------------------------------------------------------
  57  * Lst_InsertBefore --
  58  *      Insert a new node with the given piece of data before the given
  59  *      node in the given list.
  60  *
  61  * Input:
  62  *      l               list to manipulate
  63  *      ln              node before which to insert d
  64  *      d               datum to be inserted
  65  *
  66  * Results:
  67  *      SUCCESS or FAILURE.
  68  *
  69  * Side Effects:
  70  *      the firstPtr field will be changed if ln is the first node in the
  71  *      list.
  72  *
  73  *-----------------------------------------------------------------------
  74  */
  75 ReturnStatus
  76 Lst_InsertBefore(Lst l, LstNode ln, void *d)
  77 {
  78     ListNode    nLNode; /* new lnode for d */
  79     ListNode    lNode = ln;
  80     List        list = l;
  81
  82
  83     /*
  84      * check validity of arguments
  85      */
  86     if (LstValid (l) && (LstIsEmpty (l) && ln == NULL))
  87         goto ok;
  88
  89     if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) {
  90         return (FAILURE);
  91     }
  92
  93     ok:
  94     PAlloc (nLNode, ListNode);
  95
  96     nLNode->datum = d;
  97     nLNode->useCount = nLNode->flags = 0;
  98
  99     if (ln == NULL) {
 100         if (list->isCirc) {
 101             nLNode->prevPtr = nLNode->nextPtr = nLNode;
 102         } else {
 103             nLNode->prevPtr = nLNode->nextPtr = NULL;
 104         }
 105         list->firstPtr = list->lastPtr = nLNode;
 106     } else {
 107         nLNode->prevPtr = lNode->prevPtr;
 108         nLNode->nextPtr = lNode;
 109
 110         if (nLNode->prevPtr != NULL) {
 111             nLNode->prevPtr->nextPtr = nLNode;
 112         }
 113         lNode->prevPtr = nLNode;
 114
 115         if (lNode == list->firstPtr) {
 116             list->firstPtr = nLNode;
 117         }
 118     }
 119
 120     return (SUCCESS);
 121 }
 122