BuildSystem: Move all userpace libraries under the userspace directory

As the number of libraries is increasing, root directory starts to
expand. This adds better organization for libraries

userspace/libraries/LibC/include/signal.h

@@ -0,0 +1,170 @@
+#ifndef _SIGNAL_H
+#define _SIGNAL_H 1
+
+// https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/signal.h.html
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#include <time.h>
+
+#define SIG_DFL		((void (*)(int))0)
+#define SIG_ERR		((void (*)(int))1)
+#define SIG_HOLD	((void (*)(int))2)
+#define SIG_IGN		((void (*)(int))3)
+
+#define __need_pthread_t
+#define __need_size_t
+#define __need_uid_t
+#define __need_pid_t
+#define __need_pthread_attr_t
+#include <sys/types.h>
+
+typedef int sig_atomic_t;
+typedef void* sigset_t;
+
+union sigval
+{
+	int		sival_int; /* Integer signal value. */
+	void*	sival_ptr; /* Pointer signal value. */
+};
+
+struct sigevent
+{
+	int				sigev_notify;					/* Notification type. */
+	int				sigev_signo;					/* Signal number. */
+	union sigval	sigev_value;					/* Signal value. */
+	void (*sigev_notify_function)(union sigval);	/* Notification function. */
+	pthread_attr_t*	sigev_notify_attributes;  		/* Notification attributes. */
+};
+
+#define SIGEV_NONE		1
+#define SIGEV_SIGNAL	2
+#define SIGEV_THREAD	3
+
+#define SIGABRT 	1
+#define SIGALRM 	2
+#define SIGBUS 		3
+#define SIGCHLD 	4
+#define SIGCONT 	5
+#define SIGFPE 		6
+#define SIGHUP 		7
+#define SIGILL 		8
+#define SIGINT 		9
+#define SIGKILL 	10
+#define SIGPIPE 	11
+#define SIGQUIT 	12
+#define SIGSEGV 	13
+#define SIGSTOP 	14
+#define SIGTERM 	15
+#define SIGTSTP 	16
+#define SIGTTIN 	17
+#define SIGTTOU 	18
+#define SIGUSR1 	19
+#define SIGUSR2 	20
+#define SIGPOLL 	21
+#define SIGPROF 	22
+#define SIGSYS 		23
+#define SIGTRAP 	24
+#define SIGURG 		25
+#define SIGVTALRM 	26
+#define SIGXCPU 	27
+#define SIGXFSZ 	28
+#define SIGRTMIN	29
+#define SIGRTMAX	(SIGRTMIN+32)
+
+#define _SIGMIN SIGABRT
+#define _SIGMAX SIGRTMAX
+
+#define SIG_BLOCK	1
+#define SIG_UNBLOCK	2
+#define SIG_SETMASK	3
+
+#define SA_NOCLDSTOP	0x001
+#define SA_ONSTACK		0x002
+#define SA_RESETHAND	0x004
+#define SA_RESTART		0x008
+#define SA_SIGINFO		0x010
+#define SA_NOCLDWAIT	0x020
+#define SA_NODEFER		0x040
+#define SS_ONSTACK		0x080
+#define SS_DISABLE		0x100
+#define MINSIGSTKSZ		0x200
+#define SIGSTKSZ		0x400
+
+typedef struct
+{
+	void**	ss_sp;		/* Stack base or pointer. */
+	size_t	ss_size;	/* Stack size. */
+	int		ss_flags;	/* Flags. */
+} stack_t;
+
+typedef struct {} mcontext_t;
+
+typedef struct __ucontext_t
+{
+	struct __ucontext_t*	uc_link;		/* Pointer to the context that is resumed when this context returns. */
+	sigset_t				uc_sigmask;		/* The set of signals that are blocked when this context is active. */
+	stack_t					uc_stack;		/* The stack used by this context. */
+	mcontext_t				uc_mcontext;	/* A machine-specific representation of the saved context. */
+} ucontext_t;
+
+typedef struct
+{
+	int				si_signo;	/* Signal number. */
+	int				si_code;	/* Signal code. */
+	int				si_errno;	/* If non-zero, an errno value associated with this signal, as described in <errno.h>. */
+	pid_t			si_pid;		/* Sending process ID. */
+	uid_t			si_uid;		/* Real user ID of sending process. */
+	void*			si_addr;	/* Address of faulting instruction. */
+	int				si_status;	/* Exit value or signal. */
+	long			si_band;	/* Band event for SIGPOLL. */
+	union sigval	si_value;	/* Signal value. */
+} siginfo_t;
+
+struct sigaction
+{
+	void (*sa_handler)(int);						/* Pointer to a signal-catching function or one of the SIG_IGN or SIG_DFL. */
+	sigset_t	sa_mask;							/* Set of signals to be blocked during execution of the signal handling function. */
+	int			sa_flags;							/* Special flags. */
+	void (*sa_sigaction)(int, siginfo_t*, void*);	/* Pointer to a signal-catching function. */
+};
+
+// TODO: The <signal.h> header shall define the symbolic constants in the
+//       Code column of the following table for use as values of si_code
+//       that are signal-specific or non-signal-specific reasons why the
+//       signal was generated.
+
+int		kill(pid_t pid, int sig);
+int		killpg(pid_t pgpr, int sig);
+void	psiginfo(const siginfo_t* pinfo, const char* message);
+void	psignal(int signum, const char* message);
+int		pthread_kill(pthread_t thread, int sig);
+int		pthread_sigmask(int how, const sigset_t* __restrict set, sigset_t* __restrict oset);
+int		raise(int sig);
+int		sigaction(int sig, const struct sigaction* __restrict act, struct sigaction* __restrict oact);
+int		sigaddset(sigset_t* set, int signo);
+int		sigaltstack(const stack_t* __restrict ss, stack_t* __restrict oss);
+int		sigdelset(sigset_t* set, int signo);
+int		sigemptyset(sigset_t* set);
+int		sigfillset(sigset_t* set);
+int		sighold(int sig);
+int		sigignore(int sig);
+int		siginterrupt(int sig, int flag);
+int		sigismember(const sigset_t* set, int signo);
+void	(*signal(int sig, void (*func)(int)))(int);
+int		sigpause(int sig);
+int		sigpending(sigset_t* set);
+int		sigprocmask(int how, const sigset_t* __restrict set, sigset_t* __restrict oset);
+int		sigqueue(pid_t pid, int signo, union sigval value);
+int		sigrelse(int sig);
+void	(*sigset(int sig, void (*disp)(int)))(int);
+int		sigsuspend(const sigset_t* sigmask);
+int		sigtimedwait(const sigset_t* __restrict set, siginfo_t* __restrict info, const struct timespec* __restrict timeout);
+int		sigwait(const sigset_t* __restrict set, int* __restrict sig);
+int		sigwaitinfo(const sigset_t* __restrict set, siginfo_t* __restrict info);
+
+__END_DECLS
+
+#endif