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 * $FreeBSD: releng/10.2/usr.bin/make/lst.c 218909 2011-02-21 09:01:34Z brucec $ 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 "util.h" 45 46/** 47 * Lst_Append 48 * Create a new node and add it to the given list after the given node. 49 * 50 * Arguments: 51 * l affected list 52 * ln node after which to append the datum 53 * d said datum 54 * 55 * Side Effects: 56 * A new LstNode is created and linked in to the List. The lastPtr 57 * field of the List will be altered if ln is the last node in the 58 * list. lastPtr and firstPtr will alter if the list was empty and 59 * ln was NULL. 60 */ 61void 62Lst_Append(Lst *list, LstNode *ln, void *d) 63{ 64 LstNode *nLNode; 65 66 nLNode = emalloc(sizeof(*nLNode)); 67 nLNode->datum = d; 68 69 if (ln == NULL) { 70 nLNode->nextPtr = nLNode->prevPtr = NULL; 71 list->firstPtr = list->lastPtr = nLNode; 72 } else { 73 nLNode->prevPtr = ln; 74 nLNode->nextPtr = ln->nextPtr; 75 76 ln->nextPtr = nLNode; 77 if (nLNode->nextPtr != NULL) { 78 nLNode->nextPtr->prevPtr = nLNode; 79 } 80 81 if (ln == list->lastPtr) { 82 list->lastPtr = nLNode; 83 } 84 } 85} 86 87/** 88 * Lst_Concat 89 * Concatenate two lists. New elements are created to hold the data 90 * elements, if specified, but the elements themselves are not copied. 91 * If the elements should be duplicated to avoid confusion with another 92 * list, the Lst_Duplicate function should be called first. 93 * 94 * Arguments: 95 * list1 The list to which list2 is to be appended 96 * list2 The list to append to list1 97 * flags LST_CONCNEW if LstNode's should be duplicated 98 * LST_CONCLINK if should just be relinked 99 * 100 * Side Effects: 101 * New elements are created and appended the first list. 102 */ 103void 104Lst_Concat(Lst *list1, Lst *list2, int flags) 105{ 106 LstNode *ln; /* original LstNode */ 107 LstNode *nln; /* new LstNode */ 108 LstNode *last; /* the last element in the list. Keeps 109 * bookkeeping until the end */ 110 111 if (list2->firstPtr == NULL) 112 return; 113 114 if (flags == LST_CONCLINK) { 115 /* 116 * Link the first element of the second list to the last 117 * element of the first list. If the first list isn't empty, 118 * we then link the last element of the list to the first 119 * element of the second list. The last element of the second 120 * list, if it exists, then becomes the last element of the 121 * first list. 122 */ 123 list2->firstPtr->prevPtr = list1->lastPtr; 124 if (list1->lastPtr != NULL) 125 list1->lastPtr->nextPtr = list2->firstPtr; 126 else 127 list1->firstPtr = list2->firstPtr; 128 list1->lastPtr = list2->lastPtr; 129 130 Lst_Init(list2); 131 } else { 132 /* 133 * The loop simply goes through the entire second list creating 134 * new LstNodes and filling in the nextPtr, and prevPtr to fit 135 * into list1 and its datum field from the datum field of the 136 * corresponding element in list2. The 'last' node follows the 137 * last of the new nodes along until the entire list2 has been 138 * appended. Only then does the bookkeeping catch up with the 139 * changes. During the first iteration of the loop, if 'last' 140 * is NULL, the first list must have been empty so the 141 * newly-created node is made the first node of the list. 142 */ 143 for (last = list1->lastPtr, ln = list2->firstPtr; 144 ln != NULL; 145 ln = ln->nextPtr) { 146 nln = emalloc(sizeof(*nln)); 147 nln->datum = ln->datum; 148 if (last != NULL) { 149 last->nextPtr = nln; 150 } else { 151 list1->firstPtr = nln; 152 } 153 nln->prevPtr = last; 154 last = nln; 155 } 156 157 /* 158 * Finish bookkeeping. The last new element becomes the last 159 * element of list one. 160 */ 161 list1->lastPtr = last; 162 last->nextPtr = NULL; 163 } 164} 165 166/** 167 * Lst_DeQueue 168 * Remove and return the datum at the head of the given list. 169 * 170 * Results: 171 * The datum in the node at the head or (ick) NULL if the list 172 * is empty. 173 * 174 * Side Effects: 175 * The head node is removed from the list. 176 */ 177void * 178Lst_DeQueue(Lst *l) 179{ 180 void *rd; 181 LstNode *tln; 182 183 tln = Lst_First(l); 184 if (tln == NULL) { 185 return (NULL); 186 } 187 188 rd = tln->datum; 189 Lst_Remove(l, tln); 190 return (rd); 191} 192 193/** 194 * Lst_Destroy 195 * Destroy a list and free all its resources. If the freeProc is 196 * given, it is called with the datum from each node in turn before 197 * the node is freed. 198 * 199 * Side Effects: 200 * The given list is freed in its entirety. 201 */ 202void 203Lst_Destroy(Lst *list, FreeProc *freeProc) 204{ 205 LstNode *ln; 206 207 if (list->firstPtr == NULL) 208 return; 209 210 if (freeProc != NOFREE) { 211 while ((ln = list->firstPtr) != NULL) { 212 list->firstPtr = ln->nextPtr; 213 (*freeProc)(ln->datum); 214 free(ln); 215 } 216 } else { 217 while ((ln = list->firstPtr) != NULL) { 218 list->firstPtr = ln->nextPtr; 219 free(ln); 220 } 221 } 222 list->lastPtr = NULL; 223} 224 225/** 226 * Lst_Duplicate 227 * Duplicate an entire list. If a function to copy a void * is 228 * given, the individual client elements will be duplicated as well. 229 * 230 * Arguments: 231 * dst the destination list (initialized) 232 * src the list to duplicate 233 * copyProc A function to duplicate each void 234 */ 235void 236Lst_Duplicate(Lst *dst, Lst *src, DuplicateProc *copyProc) 237{ 238 LstNode *ln; 239 240 ln = src->firstPtr; 241 while (ln != NULL) { 242 if (copyProc != NOCOPY) 243 Lst_AtEnd(dst, (*copyProc)(ln->datum)); 244 else 245 Lst_AtEnd(dst, ln->datum); 246 ln = ln->nextPtr; 247 } 248} 249 250/** 251 * Lst_Insert 252 * Insert a new node with the given piece of data before the given 253 * node in the given list. 254 * 255 * Parameters: 256 * l list to manipulate 257 * ln node before which to insert d 258 * d datum to be inserted 259 * 260 * Side Effects: 261 * the firstPtr field will be changed if ln is the first node in the 262 * list. 263 */ 264void 265Lst_Insert(Lst *list, LstNode *ln, void *d) 266{ 267 LstNode *nLNode; /* new lnode for d */ 268 269 nLNode = emalloc(sizeof(*nLNode)); 270 nLNode->datum = d; 271 272 if (ln == NULL) { 273 nLNode->prevPtr = nLNode->nextPtr = NULL; 274 list->firstPtr = list->lastPtr = nLNode; 275 } else { 276 nLNode->prevPtr = ln->prevPtr; 277 nLNode->nextPtr = ln; 278 279 if (nLNode->prevPtr != NULL) { 280 nLNode->prevPtr->nextPtr = nLNode; 281 } 282 ln->prevPtr = nLNode; 283 284 if (ln == list->firstPtr) { 285 list->firstPtr = nLNode; 286 } 287 } 288} 289 290LstNode * 291Lst_Member(Lst *list, void *d) 292{ 293 LstNode *lNode; 294 295 lNode = list->firstPtr; 296 if (lNode == NULL) { 297 return (NULL); 298 } 299 300 do { 301 if (lNode->datum == d) { 302 return (lNode); 303 } 304 lNode = lNode->nextPtr; 305 } while (lNode != NULL && lNode != list->firstPtr); 306 307 return (NULL); 308} 309 310/** 311 * Lst_Remove 312 * Remove the given node from the given list. 313 * 314 * Side Effects: 315 * The list's firstPtr will be set to NULL if ln is the last 316 * node on the list. firsPtr and lastPtr will be altered if ln is 317 * either the first or last node, respectively, on the list. 318 */ 319void 320Lst_Remove(Lst *list, LstNode *ln) 321{ 322 /* 323 * unlink it from the list 324 */ 325 if (ln->nextPtr != NULL) 326 /* unlink from the backward chain */ 327 ln->nextPtr->prevPtr = ln->prevPtr; 328 else 329 /* this was the last element */ 330 list->lastPtr = ln->prevPtr; 331 332 if (ln->prevPtr != NULL) 333 /* unlink from the forward chain */ 334 ln->prevPtr->nextPtr = ln->nextPtr; 335 else 336 /* this was the first element */ 337 list->firstPtr = ln->nextPtr; 338 339 /* 340 * note that the datum is unmolested. The caller must free it as 341 * necessary and as expected. 342 */ 343 free(ln); 344} 345