stdlib: Add pico version of __cxa_atexit

This is required for C++ applications.

Signed-off-by: Keith Packard <keithp@keithp.com>

Author: keith-packard

newlib/libc/stdlib/meson.build

@@ -66,6 +66,7 @@ pico_exit_srcs_stdlib = [
   'pico-atexit.c',
   'pico-exit.c',
   'pico-onexit.c',
+  'pico-cxa-atexit.c',
 ]
 
 newlib_exit_srcs_stdlib = [

newlib/libc/stdlib/pico-atexit.c

@@ -34,15 +34,11 @@
  */
 
 #include <stdlib.h>
-
-static void __atexit_call(int status, void *arg)
-{
-	void	(*func)(void) = arg;
-	(*func)();
-}
+#include "pico-onexit.h"
 
 int
 atexit (void (*func)(void))
 {
-	return on_exit(__atexit_call, func);
+        union on_exit_func func_u = { .atexit = func };
+	return _on_exit(PICO_ONEXIT_ATEXIT, func_u, NULL);
 }

newlib/libc/stdlib/pico-cxa-atexit.c

@@ -0,0 +1,45 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright © 2021 Keith Packard
+ *
+ * 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 copyright holder 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 COPYRIGHT HOLDERS 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
+ * COPYRIGHT HOLDER 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.
+ */
+
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include "pico-onexit.h"
+
+int
+__cxa_atexit (void (*func) (void *), void *arg, void *d)
+{
+        union on_exit_func func_u = { .cxa_atexit = func };
+        return _on_exit(PICO_ONEXIT_CXA_ATEXIT, func_u, arg);
+}

newlib/libc/stdlib/pico-onexit.c

@@ -34,25 +34,29 @@
  */
 
 #include <stdlib.h>
+#include <string.h>
 #include <sys/lock.h>
+#include "pico-onexit.h"
 
-struct _on_exit {
-	void	(*func)(int, void *);
-	void	*arg;
+struct on_exit {
+    union on_exit_func  func;
+    void                *arg;
+    int                 kind;
 };
 
-static struct _on_exit on_exits[ATEXIT_MAX];
+static struct on_exit on_exits[ATEXIT_MAX];
 
 int
-on_exit (void (*func)(int, void *),void *arg)
+_on_exit(int kind, union on_exit_func func, void *arg)
 {
 	int	ret = -1;
 	int	o;
 	__LIBC_LOCK();
 	for (o = 0; o < ATEXIT_MAX; o++) {
-		if (!on_exits[o].func) {
+		if (on_exits[o].kind == PICO_ONEXIT_EMPTY) {
 			on_exits[o].func = func;
 			on_exits[o].arg = arg;
+                        on_exits[o].kind = kind;
 			ret = 0;
 			break;
 		}
@@ -61,26 +65,45 @@ on_exit (void (*func)(int, void *),void *arg)
 	return ret;
 }
 
+int
+on_exit (void (*func)(int, void *),void *arg)
+{
+    union on_exit_func func_u = { .on_exit = func };
+    return _on_exit(PICO_ONEXIT_ONEXIT, func_u, arg);
+}
+
 void
 __call_exitprocs(int code, void *param)
 {
 	for (;;) {
-		int	i;
-		void	(*func)(int, void *) = NULL;
-		void	*arg;
+		int	                i;
+                union on_exit_func      func;
+                int                     kind = PICO_ONEXIT_EMPTY;
+		void	                *arg;
 
 		__LIBC_LOCK();
 		for (i = ATEXIT_MAX - 1; i >= 0; i--) {
-			if ((func = on_exits[i].func) != NULL) {
-				arg = on_exits[i].arg;
-				on_exits[i].func = NULL;
-				on_exits[i].arg = NULL;
+                        kind = on_exits[i].kind;
+			if (kind != PICO_ONEXIT_EMPTY) {
+                                func = on_exits[i].func;
+                                arg = on_exits[i].arg;
+                                memset(&on_exits[i], '\0', sizeof(struct on_exit));
 				break;
 			}
 		}
 		__LIBC_UNLOCK();
-		if (func == NULL)
-			break;
-		func(code, arg);
+                switch (kind) {
+                case PICO_ONEXIT_EMPTY:
+                        return;
+                case PICO_ONEXIT_ONEXIT:
+                        func.on_exit(code, arg);
+                        break;
+                case PICO_ONEXIT_ATEXIT:
+                        func.atexit();
+                        break;
+                case PICO_ONEXIT_CXA_ATEXIT:
+                        func.cxa_atexit(arg);
+                        break;
+                }
 	}
 }

newlib/libc/stdlib/pico-onexit.h

@@ -0,0 +1,48 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright © 2021 Keith Packard
+ *
+ * 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 copyright holder 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 COPYRIGHT HOLDERS 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
+ * COPYRIGHT HOLDER 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.
+ */
+
+#define PICO_ONEXIT_EMPTY       0
+#define PICO_ONEXIT_ONEXIT      1
+#define PICO_ONEXIT_ATEXIT      2
+#define PICO_ONEXIT_CXA_ATEXIT  3
+
+union on_exit_func {
+    void        (*on_exit)(int, void *);
+    void        (*atexit)(void);
+    void        (*cxa_atexit)(void *);
+};
+
+int
+_on_exit(int kind, union on_exit_func func, void *arg);