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32 * $DragonFly: src/usr.bin/make/lst.c,v 1.5 2005/04/07 00:44:18 okumoto Exp $
37 * Routines to maintain a linked list of objects.
49 * Create a new node and add it to the given list after the given node.
53 * ln node after which to append the datum
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
63 Lst_Append(Lst *list, LstNode *ln, void *d)
67 nLNode = emalloc(sizeof(*nLNode));
71 nLNode->nextPtr = nLNode->prevPtr = NULL;
72 list->firstPtr = list->lastPtr = nLNode;
75 nLNode->nextPtr = ln->nextPtr;
78 if (nLNode->nextPtr != NULL) {
79 nLNode->nextPtr->prevPtr = nLNode;
82 if (ln == list->lastPtr) {
83 list->lastPtr = nLNode;
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.
96 * SUCCESS if all went well. FAILURE otherwise.
99 * list1 The list to which list2 is to be appended
100 * list2 The list to append to list1
101 * flags LST_CONCNEW if LstNode's should be duplicated
102 * LST_CONCLINK if should just be relinked
105 * New elements are created and appended the the first list.
108 Lst_Concat(Lst *list1, Lst *list2, int flags)
110 LstNode *ln; /* original LstNode */
111 LstNode *nln; /* new LstNode */
112 LstNode *last; /* the last element in the list. Keeps
113 * bookkeeping until the end */
115 if (list2->firstPtr == NULL)
118 if (flags == LST_CONCLINK) {
120 * Link the first element of the second list to the last
121 * element of the first list. If the first list isn't empty,
122 * we then link the last element of the list to the first
123 * element of the second list. The last element of the second
124 * list, if it exists, then becomes the last element of the
127 list2->firstPtr->prevPtr = list1->lastPtr;
128 if (list1->lastPtr != NULL)
129 list1->lastPtr->nextPtr = list2->firstPtr;
131 list1->firstPtr = list2->firstPtr;
132 list1->lastPtr = list2->lastPtr;
137 * The loop simply goes through the entire second list creating
138 * new LstNodes and filling in the nextPtr, and prevPtr to fit
139 * into list1 and its datum field from the datum field of the
140 * corresponding element in list2. The 'last' node follows the
141 * last of the new nodes along until the entire list2 has been
142 * appended. Only then does the bookkeeping catch up with the
143 * changes. During the first iteration of the loop, if 'last'
144 * is NULL, the first list must have been empty so the
145 * newly-created node is made the first node of the list.
147 for (last = list1->lastPtr, ln = list2->firstPtr;
150 nln = emalloc(sizeof(*nln));
151 nln->datum = ln->datum;
155 list1->firstPtr = nln;
162 * Finish bookkeeping. The last new element becomes the last
163 * element of list one.
165 list1->lastPtr = last;
166 last->nextPtr = NULL;
172 * Remove and return the datum at the head of the given list.
175 * The datum in the node at the head or (ick) NULL if the list
179 * The head node is removed from the list.
199 * Destroy a list and free all its resources. If the freeProc is
200 * given, it is called with the datum from each node in turn before
204 * The given list is freed in its entirety.
207 Lst_Destroy(Lst *list, FreeProc *freeProc)
211 if (list->firstPtr == NULL)
214 if (freeProc != NOFREE) {
215 while ((ln = list->firstPtr) != NULL) {
216 list->firstPtr = ln->nextPtr;
217 (*freeProc)(ln->datum);
221 while ((ln = list->firstPtr) != NULL) {
222 list->firstPtr = ln->nextPtr;
226 list->lastPtr = NULL;
231 * Duplicate an entire list. If a function to copy a void * is
232 * given, the individual client elements will be duplicated as well.
235 * dst the destination list (initialized)
236 * src the list to duplicate
237 * copyProc A function to duplicate each void
240 Lst_Duplicate(Lst *dst, Lst *src, DuplicateProc *copyProc)
246 if (copyProc != NOCOPY)
247 Lst_AtEnd(dst, (*copyProc)(ln->datum));
249 Lst_AtEnd(dst, ln->datum);
256 * Insert a new node with the given piece of data before the given
257 * node in the given list.
260 * l list to manipulate
261 * ln node before which to insert d
262 * d datum to be inserted
265 * the firstPtr field will be changed if ln is the first node in the
269 Lst_Insert(Lst *list, LstNode *ln, void *d)
271 LstNode *nLNode; /* new lnode for d */
273 nLNode = emalloc(sizeof(*nLNode));
277 nLNode->prevPtr = nLNode->nextPtr = NULL;
278 list->firstPtr = list->lastPtr = nLNode;
280 nLNode->prevPtr = ln->prevPtr;
281 nLNode->nextPtr = ln;
283 if (nLNode->prevPtr != NULL) {
284 nLNode->prevPtr->nextPtr = nLNode;
286 ln->prevPtr = nLNode;
288 if (ln == list->firstPtr) {
289 list->firstPtr = nLNode;
295 Lst_Member(Lst *list, void *d)
299 lNode = list->firstPtr;
305 if (lNode->datum == d) {
308 lNode = lNode->nextPtr;
309 } while (lNode != NULL && lNode != list->firstPtr);
316 * Remove the given node from the given list.
319 * SUCCESS or FAILURE.
322 * The list's firstPtr will be set to NULL if ln is the last
323 * node on the list. firsPtr and lastPtr will be altered if ln is
324 * either the first or last node, respectively, on the list.
327 Lst_Remove(Lst *list, LstNode *ln)
330 * unlink it from the list
332 if (ln->nextPtr != NULL)
333 /* unlink from the backward chain */
334 ln->nextPtr->prevPtr = ln->prevPtr;
336 /* this was the last element */
337 list->lastPtr = ln->prevPtr;
339 if (ln->prevPtr != NULL)
340 /* unlink from the forward chain */
341 ln->prevPtr->nextPtr = ln->nextPtr;
343 /* this was the first element */
344 list->firstPtr = ln->nextPtr;
347 * note that the datum is unmolested. The caller must free it as
348 * necessary and as expected.