usr.bin/make/lst.c

   1 /*-
   2  * Copyright (c) 1988, 1989, 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Adam de Boor.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $DragonFly: src/usr.bin/make/lst.c,v 1.7 2005/07/19 18:12:46 okumoto Exp $
  33  */
  34
  35 /*-
  36  * lst.c --
  37  *      Routines to maintain a linked list of objects.
  38  */
  39
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42
  43 #include "lst.h"
  44 #include "make.h"
  45 #include "util.h"
  46
  47 /**
  48  * Lst_Append
  49  *      Create a new node and add it to the given list after the given node.
  50  *
  51  * Arguments:
  52  *      l       affected list
  53  *      ln      node after which to append the datum
  54  *      d       said datum
  55  *
  56  * Side Effects:
  57  *      A new LstNode is created and linked in to the List. The lastPtr
  58  *      field of the List will be altered if ln is the last node in the
  59  *      list. lastPtr and firstPtr will alter if the list was empty and
  60  *      ln was NULL.
  61  */
  62 void
  63 Lst_Append(Lst *list, LstNode *ln, void *d)
  64 {
  65         LstNode *nLNode;
  66
  67         nLNode = emalloc(sizeof(*nLNode));
  68         nLNode->datum = d;
  69
  70         if (ln == NULL) {
  71                 nLNode->nextPtr = nLNode->prevPtr = NULL;
  72                 list->firstPtr = list->lastPtr = nLNode;
  73         } else {
  74                 nLNode->prevPtr = ln;
  75                 nLNode->nextPtr = ln->nextPtr;
  76
  77                 ln->nextPtr = nLNode;
  78                 if (nLNode->nextPtr != NULL) {
  79                         nLNode->nextPtr->prevPtr = nLNode;
  80                 }
  81
  82                 if (ln == list->lastPtr) {
  83                         list->lastPtr = nLNode;
  84                 }
  85         }
  86 }
  87
  88 /**
  89  * Lst_Concat
  90  *      Concatenate two lists. New elements are created to hold the data
  91  *      elements, if specified, but the elements themselves are not copied.
  92  *      If the elements should be duplicated to avoid confusion with another
  93  *      list, the Lst_Duplicate function should be called first.
  94  *
  95  * Arguments:
  96  *      list1   The list to which list2 is to be appended
  97  *      list2   The list to append to list1
  98  *      flags   LST_CONCNEW if LstNode's should be duplicated
  99  *              LST_CONCLINK if should just be relinked
 100  *
 101  * Side Effects:
 102  *      New elements are created and appended the the first list.
 103  */
 104 void
 105 Lst_Concat(Lst *list1, Lst *list2, int flags)
 106 {
 107         LstNode *ln;    /* original LstNode */
 108         LstNode *nln;   /* new LstNode */
 109         LstNode *last;  /* the last element in the list. Keeps
 110                          * bookkeeping until the end */
 111
 112         if (list2->firstPtr == NULL)
 113                 return;
 114
 115         if (flags == LST_CONCLINK) {
 116                 /*
 117                  * Link the first element of the second list to the last
 118                  * element of the first list. If the first list isn't empty,
 119                  * we then link the last element of the list to the first
 120                  * element of the second list. The last element of the second
 121                  * list, if it exists, then becomes the last element of the
 122                  * first list.
 123                  */
 124                 list2->firstPtr->prevPtr = list1->lastPtr;
 125                 if (list1->lastPtr != NULL)
 126                         list1->lastPtr->nextPtr = list2->firstPtr;
 127                 else
 128                         list1->firstPtr = list2->firstPtr;
 129                 list1->lastPtr = list2->lastPtr;
 130
 131                 Lst_Init(list2);
 132         } else {
 133                 /*
 134                  * The loop simply goes through the entire second list creating
 135                  * new LstNodes and filling in the nextPtr, and prevPtr to fit
 136                  * into list1 and its datum field from the datum field of the
 137                  * corresponding element in list2. The 'last' node follows the
 138                  * last of the new nodes along until the entire list2 has been
 139                  * appended. Only then does the bookkeeping catch up with the
 140                  * changes. During the first iteration of the loop, if 'last'
 141                  * is NULL, the first list must have been empty so the
 142                  * newly-created node is made the first node of the list.
 143                  */
 144                 for (last = list1->lastPtr, ln = list2->firstPtr;
 145                     ln != NULL;
 146                     ln = ln->nextPtr) {
 147                         nln = emalloc(sizeof(*nln));
 148                         nln->datum = ln->datum;
 149                         if (last != NULL) {
 150                                 last->nextPtr = nln;
 151                         } else {
 152                                 list1->firstPtr = nln;
 153                         }
 154                         nln->prevPtr = last;
 155                         last = nln;
 156                 }
 157
 158                 /*
 159                  * Finish bookkeeping. The last new element becomes the last
 160                  * element of list one.
 161                  */
 162                 list1->lastPtr = last;
 163                 last->nextPtr = NULL;
 164         }
 165 }
 166
 167 /**
 168  * Lst_DeQueue
 169  *      Remove and return the datum at the head of the given list.
 170  *
 171  * Results:
 172  *      The datum in the node at the head or (ick) NULL if the list
 173  *      is empty.
 174  *
 175  * Side Effects:
 176  *      The head node is removed from the list.
 177  */
 178 void *
 179 Lst_DeQueue(Lst *l)
 180 {
 181         void *rd;
 182         LstNode *tln;
 183
 184         tln = Lst_First(l);
 185         if (tln == NULL) {
 186                 return (NULL);
 187         }
 188
 189         rd = tln->datum;
 190         Lst_Remove(l, tln);
 191         return (rd);
 192 }
 193
 194 /**
 195  * Lst_Destroy
 196  *      Destroy a list and free all its resources. If the freeProc is
 197  *      given, it is called with the datum from each node in turn before
 198  *      the node is freed.
 199  *
 200  * Side Effects:
 201  *      The given list is freed in its entirety.
 202  */
 203 void
 204 Lst_Destroy(Lst *list, FreeProc *freeProc)
 205 {
 206         LstNode *ln;
 207
 208         if (list->firstPtr == NULL)
 209                 return;
 210
 211         if (freeProc != NOFREE) {
 212                 while ((ln = list->firstPtr) != NULL) {
 213                         list->firstPtr = ln->nextPtr;
 214                         (*freeProc)(ln->datum);
 215                         free(ln);
 216                 }
 217         } else {
 218                 while ((ln = list->firstPtr) != NULL) {
 219                         list->firstPtr = ln->nextPtr;
 220                         free(ln);
 221                 }
 222         }
 223         list->lastPtr = NULL;
 224 }
 225
 226 /**
 227  * Lst_Duplicate
 228  *      Duplicate an entire list. If a function to copy a void * is
 229  *      given, the individual client elements will be duplicated as well.
 230  *
 231  * Arguments:
 232  *      dst     the destination list (initialized)
 233  *      src     the list to duplicate
 234  *      copyProc A function to duplicate each void
 235  */
 236 void
 237 Lst_Duplicate(Lst *dst, Lst *src, DuplicateProc *copyProc)
 238 {
 239         LstNode *ln;
 240
 241         ln = src->firstPtr;
 242         while (ln != NULL) {
 243                 if (copyProc != NOCOPY)
 244                         Lst_AtEnd(dst, (*copyProc)(ln->datum));
 245                 else
 246                         Lst_AtEnd(dst, ln->datum);
 247                 ln = ln->nextPtr;
 248         }
 249 }
 250
 251 /**
 252  * Lst_Insert
 253  *      Insert a new node with the given piece of data before the given
 254  *      node in the given list.
 255  *
 256  * Parameters:
 257  *      l       list to manipulate
 258  *      ln      node before which to insert d
 259  *      d       datum to be inserted
 260  *
 261  * Side Effects:
 262  *      the firstPtr field will be changed if ln is the first node in the
 263  *      list.
 264  */
 265 void
 266 Lst_Insert(Lst *list, LstNode *ln, void *d)
 267 {
 268         LstNode *nLNode;        /* new lnode for d */
 269
 270         nLNode = emalloc(sizeof(*nLNode));
 271         nLNode->datum = d;
 272
 273         if (ln == NULL) {
 274                 nLNode->prevPtr = nLNode->nextPtr = NULL;
 275                 list->firstPtr = list->lastPtr = nLNode;
 276         } else {
 277                 nLNode->prevPtr = ln->prevPtr;
 278                 nLNode->nextPtr = ln;
 279
 280                 if (nLNode->prevPtr != NULL) {
 281                         nLNode->prevPtr->nextPtr = nLNode;
 282                 }
 283                 ln->prevPtr = nLNode;
 284
 285                 if (ln == list->firstPtr) {
 286                         list->firstPtr = nLNode;
 287                 }
 288         }
 289 }
 290
 291 LstNode *
 292 Lst_Member(Lst *list, const void *d)
 293 {
 294         LstNode *lNode;
 295
 296         lNode = list->firstPtr;
 297         if (lNode == NULL) {
 298                 return (NULL);
 299         }
 300
 301         do {
 302                 if (lNode->datum == d) {
 303                         return (lNode);
 304                 }
 305                 lNode = lNode->nextPtr;
 306         } while (lNode != NULL && lNode != list->firstPtr);
 307
 308         return (NULL);
 309 }
 310
 311 /**
 312  * Lst_Remove
 313  *      Remove the given node from the given list.
 314  *
 315  * Side Effects:
 316  *      The list's firstPtr will be set to NULL if ln is the last
 317  *      node on the list. firsPtr and lastPtr will be altered if ln is
 318  *      either the first or last node, respectively, on the list.
 319  */
 320 void
 321 Lst_Remove(Lst *list, LstNode *ln)
 322 {
 323         /*
 324          * unlink it from the list
 325          */
 326         if (ln->nextPtr != NULL)
 327                 /* unlink from the backward chain */
 328                 ln->nextPtr->prevPtr = ln->prevPtr;
 329         else
 330                 /* this was the last element */
 331                 list->lastPtr = ln->prevPtr;
 332
 333         if (ln->prevPtr != NULL)
 334                 /* unlink from the forward chain */
 335                 ln->prevPtr->nextPtr = ln->nextPtr;
 336         else
 337                 /* this was the first element */
 338                 list->firstPtr = ln->nextPtr;
 339
 340         /*
 341          * note that the datum is unmolested. The caller must free it as
 342          * necessary and as expected.
 343          */
 344         free(ln);
 345 }