scc

commit cae77758d639ac4ec3883dfebfc48641adf3d358
parent 8587dc4a95607e21c0ca737f6e4eafc1e8b903a6
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Wed,  1 Mar 2017 16:56:08 +0100

[libc] Add exit() and atexit()

Diffstat:
M
libc/include/stdlib.h
 | 
2
++
M
libc/src/Makefile
 | 
2
+-
A
libc/src/atexit.c
 | 
18
++++++++++++++++++
A
libc/src/exit.c
 | 
15
+++++++++++++++

4 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
@@ -8,6 +8,8 @@
 #define NULL ((void *) 0)
 #endif
 
+#define _ATEXIT_MAX 32
+
 #define MB_CUR_MAX 1
 #define RAND_MAX 32767
 
diff --git a/libc/src/Makefile b/libc/src/Makefile
@@ -10,7 +10,7 @@ LIBCOBJ = assert.o strcpy.o strcmp.o strlen.o strchr.o \
           isalnum.o isalpha.o isascii.o isblank.o iscntrl.o isdigit.o \
           isgraph.o islower.o isprint.o ispunct.o isspace.o isupper.o \
           isxdigit.o toupper.o tolower.o ctype.o setlocale.o \
-          localeconv.o atoi.o
+          localeconv.o atoi.o atexit.o exit.o
 
 all: libc.a
 
diff --git a/libc/src/atexit.c b/libc/src/atexit.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+
+#include <stdlib.h>
+
+extern void (*_atexitf[_ATEXIT_MAX])(void);
+
+int
+atexit(void (*fun)(void))
+{
+	void (**bp)(void);
+
+	for (bp = _atexitf; bp < &_atexitf[_ATEXIT_MAX] && *bp; ++bp)
+		/* nothing */;
+	if (bp == &_atexitf[_ATEXIT_MAX])
+		return 0;
+	*bp = fun;
+	return 1;
+}
diff --git a/libc/src/exit.c b/libc/src/exit.c
@@ -0,0 +1,15 @@
+/* See LICENSE file for copyright and license details. */
+
+#include <stdlib.h>
+
+void (*_atexitf[_ATEXIT_MAX])(void);
+
+void
+exit(int status)
+{
+	void (**bp)(void);
+
+	for (bp = _atexitf; bp < &_atexitf[_ATEXIT_MAX] && *bp; ++bp)
+		(*bp)();
+	_Exit();
+}