auto import from //depot/cupcake/@135843
diff --git a/libc/stdio/findfp.c b/libc/stdio/findfp.c
new file mode 100644
index 0000000..a55a65d
--- /dev/null
+++ b/libc/stdio/findfp.c
@@ -0,0 +1,181 @@
+/* $OpenBSD: findfp.c,v 1.9 2005/08/08 08:05:36 espie Exp $ */
+/*-
+ * Copyright (c) 1990, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * 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.
+ */
+
+#include <sys/param.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include "local.h"
+#include "glue.h"
+
+int __sdidinit;
+
+#define NDYNAMIC 10 /* add ten more whenever necessary */
+
+#define std(flags, file) \
+ {0,0,0,flags,file,{0,0},0,__sF+file,__sclose,__sread,__sseek,__swrite, \
+ {(unsigned char *)(__sFext+file), 0},NULL,0,{0,0,0},{0},{0,0},0,0}
+/* p r w flags file _bf z cookie close read seek write
+ ext */
+
+ /* the usual - (stdin + stdout + stderr) */
+static FILE usual[FOPEN_MAX - 3];
+static struct __sfileext usualext[FOPEN_MAX - 3];
+static struct glue uglue = { 0, FOPEN_MAX - 3, usual };
+
+struct __sfileext __sFext[3];
+FILE __sF[3] = {
+ std(__SRD, STDIN_FILENO), /* stdin */
+ std(__SWR, STDOUT_FILENO), /* stdout */
+ std(__SWR|__SNBF, STDERR_FILENO) /* stderr */
+};
+struct glue __sglue = { &uglue, 3, __sF };
+
+static struct glue *
+moreglue(int n)
+{
+ struct glue *g;
+ FILE *p;
+ struct __sfileext *pext;
+ static FILE empty;
+ char *data;
+
+ data = malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE)
+ + n * sizeof(struct __sfileext));
+ if (data == NULL)
+ return (NULL);
+ g = (struct glue *)data;
+ p = (FILE *)ALIGN(data + sizeof(*g));
+ pext = (struct __sfileext *)
+ (ALIGN(data + sizeof(*g)) + n * sizeof(FILE));
+ g->next = NULL;
+ g->niobs = n;
+ g->iobs = p;
+ while (--n >= 0) {
+ *p = empty;
+ _FILEEXT_SETUP(p, pext);
+ p++;
+ pext++;
+ }
+ return (g);
+}
+
+/*
+ * Find a free FILE for fopen et al.
+ */
+FILE *
+__sfp(void)
+{
+ FILE *fp;
+ int n;
+ struct glue *g;
+
+ if (!__sdidinit)
+ __sinit();
+ for (g = &__sglue;; g = g->next) {
+ for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
+ if (fp->_flags == 0)
+ goto found;
+ if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL)
+ break;
+ }
+ return (NULL);
+found:
+ fp->_flags = 1; /* reserve this slot; caller sets real flags */
+ fp->_p = NULL; /* no current pointer */
+ fp->_w = 0; /* nothing to read or write */
+ fp->_r = 0;
+ fp->_bf._base = NULL; /* no buffer */
+ fp->_bf._size = 0;
+ fp->_lbfsize = 0; /* not line buffered */
+ fp->_file = -1; /* no file */
+/* fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */
+ fp->_lb._base = NULL; /* no line buffer */
+ fp->_lb._size = 0;
+ _FILEEXT_INIT(fp);
+ return (fp);
+}
+
+#if 0
+#define getdtablesize() sysconf(_SC_OPEN_MAX)
+
+/*
+ * XXX. Force immediate allocation of internal memory. Not used by stdio,
+ * but documented historically for certain applications. Bad applications.
+ */
+void
+f_prealloc(void)
+{
+ struct glue *g;
+ int n;
+
+ n = getdtablesize() - FOPEN_MAX + 20; /* 20 for slop. */
+ for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
+ /* void */;
+ if (n > 0)
+ g->next = moreglue(n);
+}
+#endif
+
+/*
+ * exit() and abort() call _cleanup() through the callback registered
+ * with __atexit_register_cleanup(), set whenever we open or buffer a
+ * file. This chicanery is done so that programs that do not use stdio
+ * need not link it all in.
+ *
+ * The name `_cleanup' is, alas, fairly well known outside stdio.
+ */
+void
+_cleanup(void)
+{
+ /* (void) _fwalk(fclose); */
+ (void) _fwalk(__sflush); /* `cheating' */
+}
+
+/*
+ * __sinit() is called whenever stdio's internal variables must be set up.
+ */
+void
+__sinit(void)
+{
+ int i;
+
+ for (i = 0; i < FOPEN_MAX - 3; i++) {
+ _FILEEXT_SETUP(usual+i, usualext+i);
+ }
+ /* make sure we clean up on exit */
+ __atexit_register_cleanup(_cleanup); /* conservative */
+ __sdidinit = 1;
+}