Add a "fork" of musl as //fusl.

fusl/include/signal.h

+#ifndef _SIGNAL_H
+#define _SIGNAL_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <features.h>
+
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
+ || defined(_BSD_SOURCE)
+
+#ifdef _GNU_SOURCE
+#define __ucontext ucontext
+#endif
+
+#define __NEED_size_t
+#define __NEED_pid_t
+#define __NEED_uid_t
+#define __NEED_struct_timespec
+#define __NEED_pthread_t
+#define __NEED_pthread_attr_t
+#define __NEED_time_t
+#define __NEED_clock_t
+#define __NEED_sigset_t
+
+#include <bits/alltypes.h>
+
+#define SIG_HOLD ((void (*)(int)) 2)
+
+#define SIG_BLOCK     0
+#define SIG_UNBLOCK   1
+#define SIG_SETMASK   2
+
+#define SI_ASYNCNL (-60)
+#define SI_TKILL (-6)
+#define SI_SIGIO (-5)
+#define SI_ASYNCIO (-4)
+#define SI_MESGQ (-3)
+#define SI_TIMER (-2)
+#define SI_QUEUE (-1)
+#define SI_USER 0
+#define SI_KERNEL 128
+
+#define FPE_INTDIV 1
+#define FPE_INTOVF 2
+#define FPE_FLTDIV 3
+#define FPE_FLTOVF 4
+#define FPE_FLTUND 5
+#define FPE_FLTRES 6
+#define FPE_FLTINV 7
+#define FPE_FLTSUB 8
+
+#define ILL_ILLOPC 1
+#define ILL_ILLOPN 2
+#define ILL_ILLADR 3
+#define ILL_ILLTRP 4
+#define ILL_PRVOPC 5
+#define ILL_PRVREG 6
+#define ILL_COPROC 7
+#define ILL_BADSTK 8
+
+#define SEGV_MAPERR 1
+#define SEGV_ACCERR 2
+#define SEGV_BNDERR 3
+
+#define BUS_ADRALN 1
+#define BUS_ADRERR 2
+#define BUS_OBJERR 3
+#define BUS_MCEERR_AR 4
+#define BUS_MCEERR_AO 5
+
+#define CLD_EXITED 1
+#define CLD_KILLED 2
+#define CLD_DUMPED 3
+#define CLD_TRAPPED 4
+#define CLD_STOPPED 5
+#define CLD_CONTINUED 6
+
+typedef struct sigaltstack stack_t;
+
+union sigval {
+        int sival_int;
+        void *sival_ptr;
+};
+
+typedef struct {
+        int si_signo, si_errno, si_code;
+        union {
+                char __pad[128 - 2*sizeof(int) - sizeof(long)];
+                struct {
+                        union {
+                                struct {
+                                        pid_t si_pid;
+                                        uid_t si_uid;
+                                } __piduid;
+                                struct {
+                                        int si_timerid;
+                                        int si_overrun;
+                                } __timer;
+                        } __first;
+                        union {
+                                union sigval si_value;
+                                struct {
+                                        int si_status;
+                                        clock_t si_utime, si_stime;
+                                } __sigchld;
+                        } __second;
+                } __si_common;
+                struct {
+                        void *si_addr;
+                        short si_addr_lsb;
+                        struct {
+                                void *si_lower;
+                                void *si_upper;
+                        } __addr_bnd;
+                } __sigfault;
+                struct {
+                        long si_band;
+                        int si_fd;
+                } __sigpoll;
+                struct {
+                        void *si_call_addr;
+                        int si_syscall;
+                        unsigned si_arch;
+                } __sigsys;
+        } __si_fields;
+} siginfo_t;
+#define si_pid     __si_fields.__si_common.__first.__piduid.si_pid
+#define si_uid     __si_fields.__si_common.__first.__piduid.si_uid
+#define si_status  __si_fields.__si_common.__second.__sigchld.si_status
+#define si_utime   __si_fields.__si_common.__second.__sigchld.si_utime
+#define si_stime   __si_fields.__si_common.__second.__sigchld.si_stime
+#define si_value   __si_fields.__si_common.__second.si_value
+#define si_addr    __si_fields.__sigfault.si_addr
+#define si_addr_lsb __si_fields.__sigfault.si_addr_lsb
+#define si_lower   __si_fields.__sigfault.__addr_bnd.si_lower
+#define si_upper   __si_fields.__sigfault.__addr_bnd.si_upper
+#define si_band    __si_fields.__sigpoll.si_band
+#define si_fd      __si_fields.__sigpoll.si_fd
+#define si_timerid __si_fields.__si_common.__first.__timer.si_timerid
+#define si_overrun __si_fields.__si_common.__first.__timer.si_overrun
+#define si_ptr     si_value.sival_ptr
+#define si_int     si_value.sival_int
+#define si_call_addr __si_fields.__sigsys.si_call_addr
+#define si_syscall __si_fields.__sigsys.si_syscall
+#define si_arch    __si_fields.__sigsys.si_arch
+
+struct sigaction {
+        union {
+                void (*sa_handler)(int);
+                void (*sa_sigaction)(int, siginfo_t *, void *);
+        } __sa_handler;
+        sigset_t sa_mask;
+        int sa_flags;
+        void (*sa_restorer)(void);
+};
+#define sa_handler   __sa_handler.sa_handler
+#define sa_sigaction __sa_handler.sa_sigaction
+
+struct sigevent {
+        union sigval sigev_value;
+        int sigev_signo;
+        int sigev_notify;
+        void (*sigev_notify_function)(union sigval);
+        pthread_attr_t *sigev_notify_attributes;
+        char __pad[56-3*sizeof(long)];
+};
+
+#define SIGEV_SIGNAL 0
+#define SIGEV_NONE 1
+#define SIGEV_THREAD 2
+
+int __libc_current_sigrtmin(void);
+int __libc_current_sigrtmax(void);
+
+#define SIGRTMIN  (__libc_current_sigrtmin())
+#define SIGRTMAX  (__libc_current_sigrtmax())
+
+int kill(pid_t, int);
+
+int sigemptyset(sigset_t *);
+int sigfillset(sigset_t *);
+int sigaddset(sigset_t *, int);
+int sigdelset(sigset_t *, int);
+int sigismember(const sigset_t *, int);
+
+int sigprocmask(int, const sigset_t *__restrict, sigset_t *__restrict);
+int sigsuspend(const sigset_t *);
+int sigaction(int, const struct sigaction *__restrict, struct sigaction *__restrict);
+int sigpending(sigset_t *);
+int sigwait(const sigset_t *__restrict, int *__restrict);
+int sigwaitinfo(const sigset_t *__restrict, siginfo_t *__restrict);
+int sigtimedwait(const sigset_t *__restrict, siginfo_t *__restrict, const struct timespec *__restrict);
+int sigqueue(pid_t, int, const union sigval);
+
+int pthread_sigmask(int, const sigset_t *__restrict, sigset_t *__restrict);
+int pthread_kill(pthread_t, int);
+
+void psiginfo(const siginfo_t *, const char *);
+void psignal(int, const char *);
+
+#endif
+
+#if defined(_XOPEN_SOURCE) || defined(_BSD_SOURCE) || defined(_GNU_SOURCE)
+int killpg(pid_t, int);
+int sigaltstack(const stack_t *__restrict, stack_t *__restrict);
+int sighold(int);
+int sigignore(int);
+int siginterrupt(int, int);
+int sigpause(int);
+int sigrelse(int);
+void (*sigset(int, void (*)(int)))(int);
+#define TRAP_BRKPT 1
+#define TRAP_TRACE 2
+#define POLL_IN 1
+#define POLL_OUT 2
+#define POLL_MSG 3
+#define POLL_ERR 4
+#define POLL_PRI 5
+#define POLL_HUP 6
+#define SS_ONSTACK    1
+#define SS_DISABLE    2
+#endif
+
+#if defined(_BSD_SOURCE) || defined(_GNU_SOURCE)
+#define NSIG _NSIG
+typedef void (*sig_t)(int);
+#endif
+
+#ifdef _GNU_SOURCE
+typedef void (*sighandler_t)(int);
+void (*bsd_signal(int, void (*)(int)))(int);
+int sigisemptyset(const sigset_t *);
+int sigorset (sigset_t *, const sigset_t *, const sigset_t *);
+int sigandset(sigset_t *, const sigset_t *, const sigset_t *);
+
+#define SA_NOMASK SA_NODEFER
+#define SA_ONESHOT SA_RESETHAND
+#endif
+
+#include <bits/signal.h>
+
+#define SIG_ERR  ((void (*)(int))-1)
+#define SIG_DFL  ((void (*)(int)) 0)
+#define SIG_IGN  ((void (*)(int)) 1)
+
+typedef int sig_atomic_t;
+
+void (*signal(int, void (*)(int)))(int);
+int raise(int);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif