usr: libc: Add stdlib.h exit routines

* Added stdlib.h
* Added abort(), exit(), and _Exit()

Signed-off-by: Quinn Stephens <quinn@osmora.org>
Signed-off-by: Ian Moffett <ian@osmora.org>

4 files changed, 208 insertions, 0 deletions

diff --git a/lib/libc/include/stdlib.h b/lib/libc/include/stdlib.h
new file mode 100644
index 0000000..054bdca
--- /dev/null
+++ b/lib/libc/include/stdlib.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * 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 Hyra 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 OWNER 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.
+ */
+
+#ifndef _STDLIB_H
+#define _STDLIB_H 1
+
+/* For __dead */
+#include <sys/cdefs.h>
+
+/* Get specific definitions from stddef.h */
+#define __need_NULL
+#define __need_size_t
+#define __need_wchar_t
+#include <stddef.h>
+
+#if __STDC_VERSION__ >= 202311L
+#define __STDC_VERSION_STDLIB_H__ 202311L
+#endif
+
+#define EXIT_SUCCESS 0
+#define EXIT_FAILURE 1
+
+typedef struct {
+    int quot;
+    int rem;
+} div_t;
+
+#ifndef __ldiv_t_defined
+typedef struct {
+    long int quot;
+    long int rem;
+} ldiv_t;
+#define __ldiv_t_defined 1
+#endif /* !__ldiv_t_defined */
+
+#ifndef __lldiv_t_defined
+typedef struct {
+    long long int quot;
+    long long int rem;
+} lldiv_t;
+#define __lldiv_t_defined 1
+#endif /* !__lldiv_t_defined */
+
+__BEGIN_DECLS
+
+#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L) || (defined(__cplusplus) && __cplusplus >= 201103L)
+[[noreturn]] void abort(void);
+[[noreturn]] void exit(int status);
+[[noreturn]] void _Exit(int status);
+#elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
+_Noreturn void abort(void);
+_Noreturn void exit(int status);
+_Noreturn void _Exit(int status);
+#else
+__dead void abort(void);
+__dead void exit(int status);
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
+__dead void _Exit(int status);
+#endif
+#endif
+
+__END_DECLS
+
+#endif /* !_STDLIB_H */
diff --git a/lib/libc/src/stdlib/_Exit.c b/lib/libc/src/stdlib/_Exit.c
new file mode 100644
index 0000000..e975381
--- /dev/null
+++ b/lib/libc/src/stdlib/_Exit.c
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * 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 Hyra 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 OWNER 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/syscall.h>
+#include <stdlib.h>
+
+__dead void
+_Exit(int status)
+{
+    syscall(SYS_exit, status);
+    __builtin_unreachable();
+}
diff --git a/lib/libc/src/stdlib/abort.c b/lib/libc/src/stdlib/abort.c
new file mode 100644
index 0000000..bc0a491
--- /dev/null
+++ b/lib/libc/src/stdlib/abort.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * 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 Hyra 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 OWNER 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 <stdlib.h>
+
+__dead void
+abort(void)
+{
+    /*
+     * TODO: Call SIGABRT handler here.
+     */
+
+    _Exit(EXIT_FAILURE);
+}
diff --git a/lib/libc/src/stdlib/exit.c b/lib/libc/src/stdlib/exit.c
new file mode 100644
index 0000000..e5adfac
--- /dev/null
+++ b/lib/libc/src/stdlib/exit.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * 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 Hyra 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 OWNER 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 <stdlib.h>
+
+__dead void
+exit(int status)
+{
+    /*
+     * TODO: Call atexit() handlers and do cleanup here.
+     */
+
+    _Exit(status);
+}