9 files changed, 235 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/exit/_Exit.c b/libc-top-half/musl/src/exit/_Exit.c
new file mode 100644
index 0000000..7a6115c
--- /dev/null
+++ b/libc-top-half/musl/src/exit/_Exit.c
@@ -0,0 +1,8 @@
+#include <stdlib.h>
+#include "syscall.h"
+
+_Noreturn void _Exit(int ec)
+{
+	__syscall(SYS_exit_group, ec);
+	for (;;) __syscall(SYS_exit, ec);
+}
diff --git a/libc-top-half/musl/src/exit/abort.c b/libc-top-half/musl/src/exit/abort.c
new file mode 100644
index 0000000..f21f458
--- /dev/null
+++ b/libc-top-half/musl/src/exit/abort.c
@@ -0,0 +1,30 @@
+#include <stdlib.h>
+#include <signal.h>
+#include "syscall.h"
+#include "pthread_impl.h"
+#include "atomic.h"
+#include "lock.h"
+#include "ksigaction.h"
+
+_Noreturn void abort(void)
+{
+	raise(SIGABRT);
+
+	/* If there was a SIGABRT handler installed and it returned, or if
+	 * SIGABRT was blocked or ignored, take an AS-safe lock to prevent
+	 * sigaction from installing a new SIGABRT handler, uninstall any
+	 * handler that may be present, and re-raise the signal to generate
+	 * the default action of abnormal termination. */
+	__block_all_sigs(0);
+	LOCK(__abort_lock);
+	__syscall(SYS_rt_sigaction, SIGABRT,
+		&(struct k_sigaction){.handler = SIG_DFL}, 0, _NSIG/8);
+	__syscall(SYS_tkill, __pthread_self()->tid, SIGABRT);
+	__syscall(SYS_rt_sigprocmask, SIG_UNBLOCK,
+		&(long[_NSIG/(8*sizeof(long))]){1UL<<(SIGABRT-1)}, 0, _NSIG/8);
+
+	/* Beyond this point should be unreachable. */
+	a_crash();
+	raise(SIGKILL);
+	_Exit(127);
+}
diff --git a/libc-top-half/musl/src/exit/abort_lock.c b/libc-top-half/musl/src/exit/abort_lock.c
new file mode 100644
index 0000000..3af72c7
--- /dev/null
+++ b/libc-top-half/musl/src/exit/abort_lock.c
@@ -0,0 +1,3 @@
+#include "pthread_impl.h"
+
+volatile int __abort_lock[1];
diff --git a/libc-top-half/musl/src/exit/arm/__aeabi_atexit.c b/libc-top-half/musl/src/exit/arm/__aeabi_atexit.c
new file mode 100644
index 0000000..ce16101
--- /dev/null
+++ b/libc-top-half/musl/src/exit/arm/__aeabi_atexit.c
@@ -0,0 +1,6 @@
+int __cxa_atexit(void (*func)(void *), void *arg, void *dso);
+
+int __aeabi_atexit (void *obj, void (*func) (void *), void *d)
+{
+	return __cxa_atexit (func, obj, d);
+}
diff --git a/libc-top-half/musl/src/exit/assert.c b/libc-top-half/musl/src/exit/assert.c
new file mode 100644
index 0000000..94edd82
--- /dev/null
+++ b/libc-top-half/musl/src/exit/assert.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+_Noreturn void __assert_fail(const char *expr, const char *file, int line, const char *func)
+{
+	fprintf(stderr, "Assertion failed: %s (%s: %s: %d)\n", expr, file, func, line);
+	abort();
+}
diff --git a/libc-top-half/musl/src/exit/at_quick_exit.c b/libc-top-half/musl/src/exit/at_quick_exit.c
new file mode 100644
index 0000000..429d0b0
--- /dev/null
+++ b/libc-top-half/musl/src/exit/at_quick_exit.c
@@ -0,0 +1,35 @@
+#include <stdlib.h>
+#include "libc.h"
+#include "lock.h"
+#include "fork_impl.h"
+
+#define COUNT 32
+
+static void (*funcs[COUNT])(void);
+static int count;
+#if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
+static volatile int lock[1];
+volatile int *const __at_quick_exit_lockptr = lock;
+#endif
+
+void __funcs_on_quick_exit()
+{
+	void (*func)(void);
+	LOCK(lock);
+	while (count > 0) {
+		func = funcs[--count];
+		UNLOCK(lock);
+		func();
+		LOCK(lock);
+	}
+}
+
+int at_quick_exit(void (*func)(void))
+{
+	int r = 0;
+	LOCK(lock);
+	if (count == 32) r = -1;
+	else funcs[count++] = func;
+	UNLOCK(lock);
+	return r;
+}
diff --git a/libc-top-half/musl/src/exit/atexit.c b/libc-top-half/musl/src/exit/atexit.c
new file mode 100644
index 0000000..155292d
--- /dev/null
+++ b/libc-top-half/musl/src/exit/atexit.c
@@ -0,0 +1,82 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include "libc.h"
+#include "lock.h"
+#include "fork_impl.h"
+
+#define malloc __libc_malloc
+#define calloc __libc_calloc
+#define realloc undef
+#define free undef
+
+/* Ensure that at least 32 atexit handlers can be registered without malloc */
+#define COUNT 32
+
+static struct fl
+{
+	struct fl *next;
+	void (*f[COUNT])(void *);
+	void *a[COUNT];
+} builtin, *head;
+
+static int slot;
+
+#if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
+static volatile int lock[1];
+volatile int *const __atexit_lockptr = lock;
+#endif
+
+void __funcs_on_exit()
+{
+	void (*func)(void *), *arg;
+	LOCK(lock);
+	for (; head; head=head->next, slot=COUNT) while(slot-->0) {
+		func = head->f[slot];
+		arg = head->a[slot];
+		UNLOCK(lock);
+		func(arg);
+		LOCK(lock);
+	}
+}
+
+void __cxa_finalize(void *dso)
+{
+}
+
+int __cxa_atexit(void (*func)(void *), void *arg, void *dso)
+{
+	LOCK(lock);
+
+	/* Defer initialization of head so it can be in BSS */
+	if (!head) head = &builtin;
+
+	/* If the current function list is full, add a new one */
+	if (slot==COUNT) {
+		struct fl *new_fl = calloc(sizeof(struct fl), 1);
+		if (!new_fl) {
+			UNLOCK(lock);
+			return -1;
+		}
+		new_fl->next = head;
+		head = new_fl;
+		slot = 0;
+	}
+
+	/* Append function to the list. */
+	head->f[slot] = func;
+	head->a[slot] = arg;
+	slot++;
+
+	UNLOCK(lock);
+	return 0;
+}
+
+static void call(void *p)
+{
+	((void (*)(void))(uintptr_t)p)();
+}
+
+int atexit(void (*func)(void))
+{
+	return __cxa_atexit(call, (void *)(uintptr_t)func, 0);
+}
diff --git a/libc-top-half/musl/src/exit/exit.c b/libc-top-half/musl/src/exit/exit.c
new file mode 100644
index 0000000..1536d7d
--- /dev/null
+++ b/libc-top-half/musl/src/exit/exit.c
@@ -0,0 +1,52 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include "libc.h"
+
+static void dummy()
+{
+}
+
+/* atexit.c and __stdio_exit.c override these. the latter is linked
+ * as a consequence of linking either __toread.c or __towrite.c. */
+weak_alias(dummy, __funcs_on_exit);
+weak_alias(dummy, __stdio_exit);
+#ifdef __wasilibc_unmodified_upstream // fini
+weak_alias(dummy, _fini);
+
+extern weak hidden void (*const __fini_array_start)(void), (*const __fini_array_end)(void);
+
+static void libc_exit_fini(void)
+{
+	uintptr_t a = (uintptr_t)&__fini_array_end;
+	for (; a>(uintptr_t)&__fini_array_start; a-=sizeof(void(*)()))
+		(*(void (**)())(a-sizeof(void(*)())))();
+	_fini();
+}
+
+weak_alias(libc_exit_fini, __libc_exit_fini);
+#endif
+
+#ifdef __wasilibc_unmodified_upstream // WASI libc uses a custom exit
+_Noreturn void exit(int code)
+{
+	__funcs_on_exit();
+	__libc_exit_fini();
+	__stdio_exit();
+	_Exit(code);
+}
+#else
+// Split out the cleanup functions so that we can call them without calling
+// _Exit if we don't need to. This allows _start to just return if main
+// returns 0.
+void __wasm_call_dtors(void)
+{
+	__funcs_on_exit();
+	__stdio_exit();
+}
+
+_Noreturn void exit(int code)
+{
+	__wasm_call_dtors();
+	_Exit(code);
+}
+#endif
diff --git a/libc-top-half/musl/src/exit/quick_exit.c b/libc-top-half/musl/src/exit/quick_exit.c
new file mode 100644
index 0000000..ada9134
--- /dev/null
+++ b/libc-top-half/musl/src/exit/quick_exit.c
@@ -0,0 +1,11 @@
+#include <stdlib.h>
+#include "libc.h"
+
+static void dummy() { }
+weak_alias(dummy, __funcs_on_quick_exit);
+
+_Noreturn void quick_exit(int code)
+{
+	__funcs_on_quick_exit();
+	_Exit(code);
+}