Move __cxa_thread_atexit* to its own .c file to avoid pulling the code

(w/ _dlctl reference) into static executables.  It's all Mark's code so
put his preferred copyright on it.
ok kettenis@

src/lib/libc/stdlib/Makefile.inc

@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile.inc,v 1.63 2017/03/24 16:15:31 otto Exp $
+#	$OpenBSD: Makefile.inc,v 1.64 2017/12/16 20:06:55 guenther Exp $
 
 # stdlib sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_CPU}/stdlib ${LIBCSRCDIR}/stdlib
@@ -10,7 +10,9 @@ SRCS+=	a64l.c abort.c atexit.c atoi.c atof.c atol.c atoll.c bsearch.c \
 	merge.c posix_pty.c qsort.c radixsort.c rand.c random.c \
 	realpath.c remque.c setenv.c strtoimax.c \
 	strtol.c strtoll.c strtonum.c strtoul.c strtoull.c strtoumax.c \
-	system.c tfind.c tsearch.c _rand48.c drand48.c erand48.c jrand48.c \
+	system.c \
+	tfind.c thread_atexit.c tsearch.c \
+	_rand48.c drand48.c erand48.c jrand48.c \
 	lcong48.c lrand48.c mrand48.c nrand48.c seed48.c srand48.c \
 	_Exit.c icdb.c
 

src/lib/libc/stdlib/atexit.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: atexit.c,v 1.26 2017/12/05 21:11:10 kettenis Exp $ */
+/*	$OpenBSD: atexit.c,v 1.27 2017/12/16 20:06:56 guenther Exp $ */
 /*
  * Copyright (c) 2002 Daniel Hartmeier
  * All rights reserved.
@@ -31,24 +31,14 @@
 
 #include <sys/types.h>
 #include <sys/mman.h>
-#include <dlfcn.h>
-#include <elf.h>
-#pragma weak _DYNAMIC
 #include <stdlib.h>
 #include <string.h>
+#include <tib.h>
 #include <unistd.h>
+
 #include "atexit.h"
 #include "atfork.h"
 #include "thread_private.h"
-#include "tib.h"
-
-typeof(dlctl) dlctl asm("_dlctl") __attribute__((weak));
-
-struct thread_atexit_fn {
-	void (*func)(void *);
-	void *arg;
-	struct thread_atexit_fn *next;
-};
 
 struct atexit *__atexit;
 static int restartloop;
@@ -133,29 +123,6 @@ atexit(void (*fn)(void))
 }
 DEF_STRONG(atexit);
 
-__weak_alias(__cxa_thread_atexit, __cxa_thread_atexit_impl);
-
-int
-__cxa_thread_atexit_impl(void (*func)(void *), void *arg, void *dso)
-{
-	struct thread_atexit_fn *fnp;
-	struct tib *tib = TIB_GET();
-
-	fnp = calloc(1, sizeof(struct thread_atexit_fn));
-	if (fnp == NULL)
-		return -1;
-
-	if (_DYNAMIC)
-		dlctl(NULL, DL_REFERENCE, dso);
-
-	fnp->func = func;
-	fnp->arg = arg;
-	fnp->next = tib->tib_atexit;
-	tib->tib_atexit = fnp;
-
-	return 0;
-}
-
 void
 _thread_finalize(void)
 {

src/lib/libc/stdlib/atexit.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: atexit.h,v 1.11 2017/12/05 13:45:31 kettenis Exp $ */
+/*	$OpenBSD: atexit.h,v 1.12 2017/12/16 20:06:56 guenther Exp $ */
 
 /*
  * Copyright (c) 2002 Daniel Hartmeier
@@ -41,6 +41,13 @@ struct atexit {
 	} fns[1];			/* the table itself */
 };
 
+/* a chain of these are hung off each thread's TIB's tib_atexit member */
+struct thread_atexit_fn {
+	void (*func)(void *);
+	void *arg;
+	struct thread_atexit_fn *next;
+};
+
 __BEGIN_HIDDEN_DECLS
 extern struct atexit *__atexit;		/* points to head of LIFO stack */
 __END_HIDDEN_DECLS

src/lib/libc/stdlib/thread_atexit.c

@@ -0,0 +1,49 @@
+/*	$OpenBSD: thread_atexit.c,v 1.1 2017/12/16 20:06:56 guenther Exp $ */
+/*
+ * Copyright (c) 2017 Mark Kettenis <kettenis@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <dlfcn.h>
+#include <elf.h>
+#pragma weak _DYNAMIC
+#include <stdlib.h>
+#include <tib.h>
+
+#include "atexit.h"
+
+typeof(dlctl) dlctl asm("_dlctl") __attribute__((weak));
+
+__weak_alias(__cxa_thread_atexit, __cxa_thread_atexit_impl);
+
+int
+__cxa_thread_atexit_impl(void (*func)(void *), void *arg, void *dso)
+{
+	struct thread_atexit_fn *fnp;
+	struct tib *tib = TIB_GET();
+
+	fnp = calloc(1, sizeof(struct thread_atexit_fn));
+	if (fnp == NULL)
+		return -1;
+
+	if (_DYNAMIC)
+		dlctl(NULL, DL_REFERENCE, dso);
+
+	fnp->func = func;
+	fnp->arg = arg;
+	fnp->next = tib->tib_atexit;
+	tib->tib_atexit = fnp;
+
+	return 0;
+}