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mirror of https://git.FreeBSD.org/src.git synced 2024-12-12 09:58:36 +00:00
freebsd/usr.bin/make/lst.c
Hartmut Brandt 485aef42c9 Get rid of the ReturnStatus obscuration that was anyway used only
in two places. While here don't bother returning anything from
Lst_Replace - nobody ever checks the return code.

Suggested by:	jmallet
2005-05-18 06:50:39 +00:00

346 lines
8.5 KiB
C

/*-
* Copyright (c) 1988, 1989, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Adam de Boor.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*-
* lst.c --
* Routines to maintain a linked list of objects.
*/
#include <stdio.h>
#include <stdlib.h>
#include "lst.h"
#include "make.h"
#include "util.h"
/**
* Lst_Append
* Create a new node and add it to the given list after the given node.
*
* Arguments:
* l affected list
* ln node after which to append the datum
* d said datum
*
* Side Effects:
* A new LstNode is created and linked in to the List. The lastPtr
* field of the List will be altered if ln is the last node in the
* list. lastPtr and firstPtr will alter if the list was empty and
* ln was NULL.
*/
void
Lst_Append(Lst *list, LstNode *ln, void *d)
{
LstNode *nLNode;
nLNode = emalloc(sizeof(*nLNode));
nLNode->datum = d;
if (ln == NULL) {
nLNode->nextPtr = nLNode->prevPtr = NULL;
list->firstPtr = list->lastPtr = nLNode;
} else {
nLNode->prevPtr = ln;
nLNode->nextPtr = ln->nextPtr;
ln->nextPtr = nLNode;
if (nLNode->nextPtr != NULL) {
nLNode->nextPtr->prevPtr = nLNode;
}
if (ln == list->lastPtr) {
list->lastPtr = nLNode;
}
}
}
/**
* Lst_Concat
* Concatenate two lists. New elements are created to hold the data
* elements, if specified, but the elements themselves are not copied.
* If the elements should be duplicated to avoid confusion with another
* list, the Lst_Duplicate function should be called first.
*
* Arguments:
* list1 The list to which list2 is to be appended
* list2 The list to append to list1
* flags LST_CONCNEW if LstNode's should be duplicated
* LST_CONCLINK if should just be relinked
*
* Side Effects:
* New elements are created and appended the the first list.
*/
void
Lst_Concat(Lst *list1, Lst *list2, int flags)
{
LstNode *ln; /* original LstNode */
LstNode *nln; /* new LstNode */
LstNode *last; /* the last element in the list. Keeps
* bookkeeping until the end */
if (list2->firstPtr == NULL)
return;
if (flags == LST_CONCLINK) {
/*
* Link the first element of the second list to the last
* element of the first list. If the first list isn't empty,
* we then link the last element of the list to the first
* element of the second list. The last element of the second
* list, if it exists, then becomes the last element of the
* first list.
*/
list2->firstPtr->prevPtr = list1->lastPtr;
if (list1->lastPtr != NULL)
list1->lastPtr->nextPtr = list2->firstPtr;
else
list1->firstPtr = list2->firstPtr;
list1->lastPtr = list2->lastPtr;
Lst_Init(list2);
} else {
/*
* The loop simply goes through the entire second list creating
* new LstNodes and filling in the nextPtr, and prevPtr to fit
* into list1 and its datum field from the datum field of the
* corresponding element in list2. The 'last' node follows the
* last of the new nodes along until the entire list2 has been
* appended. Only then does the bookkeeping catch up with the
* changes. During the first iteration of the loop, if 'last'
* is NULL, the first list must have been empty so the
* newly-created node is made the first node of the list.
*/
for (last = list1->lastPtr, ln = list2->firstPtr;
ln != NULL;
ln = ln->nextPtr) {
nln = emalloc(sizeof(*nln));
nln->datum = ln->datum;
if (last != NULL) {
last->nextPtr = nln;
} else {
list1->firstPtr = nln;
}
nln->prevPtr = last;
last = nln;
}
/*
* Finish bookkeeping. The last new element becomes the last
* element of list one.
*/
list1->lastPtr = last;
last->nextPtr = NULL;
}
}
/**
* Lst_DeQueue
* Remove and return the datum at the head of the given list.
*
* Results:
* The datum in the node at the head or (ick) NULL if the list
* is empty.
*
* Side Effects:
* The head node is removed from the list.
*/
void *
Lst_DeQueue(Lst *l)
{
void *rd;
LstNode *tln;
tln = Lst_First(l);
if (tln == NULL) {
return (NULL);
}
rd = tln->datum;
Lst_Remove(l, tln);
return (rd);
}
/**
* Lst_Destroy
* Destroy a list and free all its resources. If the freeProc is
* given, it is called with the datum from each node in turn before
* the node is freed.
*
* Side Effects:
* The given list is freed in its entirety.
*/
void
Lst_Destroy(Lst *list, FreeProc *freeProc)
{
LstNode *ln;
if (list->firstPtr == NULL)
return;
if (freeProc != NOFREE) {
while ((ln = list->firstPtr) != NULL) {
list->firstPtr = ln->nextPtr;
(*freeProc)(ln->datum);
free(ln);
}
} else {
while ((ln = list->firstPtr) != NULL) {
list->firstPtr = ln->nextPtr;
free(ln);
}
}
list->lastPtr = NULL;
}
/**
* Lst_Duplicate
* Duplicate an entire list. If a function to copy a void * is
* given, the individual client elements will be duplicated as well.
*
* Arguments:
* dst the destination list (initialized)
* src the list to duplicate
* copyProc A function to duplicate each void
*/
void
Lst_Duplicate(Lst *dst, Lst *src, DuplicateProc *copyProc)
{
LstNode *ln;
ln = src->firstPtr;
while (ln != NULL) {
if (copyProc != NOCOPY)
Lst_AtEnd(dst, (*copyProc)(ln->datum));
else
Lst_AtEnd(dst, ln->datum);
ln = ln->nextPtr;
}
}
/**
* Lst_Insert
* Insert a new node with the given piece of data before the given
* node in the given list.
*
* Parameters:
* l list to manipulate
* ln node before which to insert d
* d datum to be inserted
*
* Side Effects:
* the firstPtr field will be changed if ln is the first node in the
* list.
*/
void
Lst_Insert(Lst *list, LstNode *ln, void *d)
{
LstNode *nLNode; /* new lnode for d */
nLNode = emalloc(sizeof(*nLNode));
nLNode->datum = d;
if (ln == NULL) {
nLNode->prevPtr = nLNode->nextPtr = NULL;
list->firstPtr = list->lastPtr = nLNode;
} else {
nLNode->prevPtr = ln->prevPtr;
nLNode->nextPtr = ln;
if (nLNode->prevPtr != NULL) {
nLNode->prevPtr->nextPtr = nLNode;
}
ln->prevPtr = nLNode;
if (ln == list->firstPtr) {
list->firstPtr = nLNode;
}
}
}
LstNode *
Lst_Member(Lst *list, void *d)
{
LstNode *lNode;
lNode = list->firstPtr;
if (lNode == NULL) {
return (NULL);
}
do {
if (lNode->datum == d) {
return (lNode);
}
lNode = lNode->nextPtr;
} while (lNode != NULL && lNode != list->firstPtr);
return (NULL);
}
/**
* Lst_Remove
* Remove the given node from the given list.
*
* Side Effects:
* The list's firstPtr will be set to NULL if ln is the last
* node on the list. firsPtr and lastPtr will be altered if ln is
* either the first or last node, respectively, on the list.
*/
void
Lst_Remove(Lst *list, LstNode *ln)
{
/*
* unlink it from the list
*/
if (ln->nextPtr != NULL)
/* unlink from the backward chain */
ln->nextPtr->prevPtr = ln->prevPtr;
else
/* this was the last element */
list->lastPtr = ln->prevPtr;
if (ln->prevPtr != NULL)
/* unlink from the forward chain */
ln->prevPtr->nextPtr = ln->nextPtr;
else
/* this was the first element */
list->firstPtr = ln->nextPtr;
/*
* note that the datum is unmolested. The caller must free it as
* necessary and as expected.
*/
free(ln);
}