minix/lib/libc/stdlib/tdelete.c
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

69 lines
1.8 KiB
C

/* $NetBSD: tdelete.c,v 1.4 2006/03/19 01:12:08 christos Exp $ */
/*
* Tree search generalized from Knuth (6.2.2) Algorithm T just like
* the AT&T man page says.
*
* The node_t structure is for internal use only, lint doesn't grok it.
*
* Written by reading the System V Interface Definition, not the code.
*
* Totally public domain.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: tdelete.c,v 1.4 2006/03/19 01:12:08 christos Exp $");
#endif /* LIBC_SCCS and not lint */
#include <assert.h>
#define _SEARCH_PRIVATE
#include <search.h>
#include <stdlib.h>
/* delete node with given key */
void *
tdelete(vkey, vrootp, compar)
const void *vkey; /* key to be deleted */
void **vrootp; /* address of the root of tree */
int (*compar) __P((const void *, const void *));
{
node_t **rootp = (node_t **)vrootp;
node_t *p, *q, *r;
int cmp;
_DIAGASSERT(vkey != NULL);
_DIAGASSERT(compar != NULL);
if (rootp == NULL || (p = *rootp) == NULL)
return NULL;
while ((cmp = (*compar)(vkey, (*rootp)->key)) != 0) {
p = *rootp;
rootp = (cmp < 0) ?
&(*rootp)->llink : /* follow llink branch */
&(*rootp)->rlink; /* follow rlink branch */
if (*rootp == NULL)
return NULL; /* key not found */
}
r = (*rootp)->rlink; /* D1: */
if ((q = (*rootp)->llink) == NULL) /* Left NULL? */
q = r;
else if (r != NULL) { /* Right link is NULL? */
if (r->llink == NULL) { /* D2: Find successor */
r->llink = q;
q = r;
} else { /* D3: Find NULL link */
for (q = r->llink; q->llink != NULL; q = r->llink)
r = q;
r->llink = q->rlink;
q->llink = (*rootp)->llink;
q->rlink = (*rootp)->rlink;
}
}
if (p != *rootp)
free(*rootp); /* D4: Free node */
*rootp = q; /* link parent to new node */
return p;
}