/* vi: set sw=4 ts=4: */
/*
 * Signal name/number conversion routines.
 *
 * Copyright 2006 Rob Landley <rob@landley.net>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//config:config FEATURE_RTMINMAX
//config:	bool "Support RTMIN[+n] and RTMAX[-n] signal names"
//config:	default y
//config:	help
//config:	  Support RTMIN[+n] and RTMAX[-n] signal names
//config:	  in kill, killall etc. This costs ~250 bytes.

#include "libbb.h"

/* Believe it or not, but some arches have more than 32 SIGs!
 * HPPA: SIGSTKFLT == 36. */

static char *signals[NSIG];

static bool signals_initialized = 0;

static void initialize_signals(void) {
	// SUSv3 says kill must support these, and specifies the numerical values,
	// http://www.opengroup.org/onlinepubs/009695399/utilities/kill.html
	// {0, "EXIT"}, {1, "HUP"}, {2, "INT"}, {3, "QUIT"},
	// {6, "ABRT"}, {9, "KILL"}, {14, "ALRM"}, {15, "TERM"}
	// And Posix adds the following:
	// {SIGILL, "ILL"}, {SIGTRAP, "TRAP"}, {SIGFPE, "FPE"}, {SIGUSR1, "USR1"},
	// {SIGSEGV, "SEGV"}, {SIGUSR2, "USR2"}, {SIGPIPE, "PIPE"}, {SIGCHLD, "CHLD"},
	// {SIGCONT, "CONT"}, {SIGSTOP, "STOP"}, {SIGTSTP, "TSTP"}, {SIGTTIN, "TTIN"},
	// {SIGTTOU, "TTOU"}

	int i;
	
	if (signals_initialized)
		return;

	for (i = 0; i < NSIG; i++) {
		signals[i] = "";
	}

	signals[0] = "EXIT";
#ifdef SIGHUP
	signals[SIGHUP   ] = "HUP";
#endif
#ifdef SIGINT
	signals[SIGINT   ] = "INT";
#endif
#ifdef SIGQUIT
	signals[SIGQUIT  ] = "QUIT";
#endif
#ifdef SIGILL
	signals[SIGILL   ] = "ILL";
#endif
#ifdef SIGTRAP
	signals[SIGTRAP  ] = "TRAP";
#endif
#ifdef SIGABRT
	signals[SIGABRT  ] = "ABRT";
#endif
#ifdef SIGBUS
	signals[SIGBUS   ] = "BUS";
#endif
#ifdef SIGFPE
	signals[SIGFPE   ] = "FPE";
#endif
#ifdef SIGKILL
	signals[SIGKILL  ] = "KILL";
#endif
#ifdef SIGUSR1
	signals[SIGUSR1  ] = "USR1";
#endif
#ifdef SIGSEGV
	signals[SIGSEGV  ] = "SEGV";
#endif
#ifdef SIGUSR2
	signals[SIGUSR2  ] = "USR2";
#endif
#ifdef SIGPIPE
	signals[SIGPIPE  ] = "PIPE";
#endif
#ifdef SIGALRM
	signals[SIGALRM  ] = "ALRM";
#endif
#ifdef SIGTERM
	signals[SIGTERM  ] = "TERM";
#endif
#ifdef SIGSTKFLT
	signals[SIGSTKFLT] = "STKFLT";
#endif
#ifdef SIGCHLD
	signals[SIGCHLD  ] = "CHLD";
#endif
#ifdef SIGCONT
	signals[SIGCONT  ] = "CONT";
#endif
#ifdef SIGSTOP
	signals[SIGSTOP  ] = "STOP";
#endif
#ifdef SIGTSTP
	signals[SIGTSTP  ] = "TSTP";
#endif
#ifdef SIGTTIN
	signals[SIGTTIN  ] = "TTIN";
#endif
#ifdef SIGTTOU
	signals[SIGTTOU  ] = "TTOU";
#endif
#ifdef SIGURG
	signals[SIGURG   ] = "URG";
#endif
#ifdef SIGXCPU
	signals[SIGXCPU  ] = "XCPU";
#endif
#ifdef SIGXFSZ
	signals[SIGXFSZ  ] = "XFSZ";
#endif
#ifdef SIGVTALRM
	signals[SIGVTALRM] = "VTALRM";
#endif
#ifdef SIGPROF
	signals[SIGPROF  ] = "PROF";
#endif
#ifdef SIGWINCH
	signals[SIGWINCH ] = "WINCH";
#endif
#ifdef SIGPOLL
	signals[SIGPOLL  ] = "POLL";
#endif
#ifdef SIGPWR
	signals[SIGPWR   ] = "PWR";
#endif
#ifdef SIGSYS
	signals[SIGSYS   ] = "SYS";
#endif
#if ENABLE_FEATURE_RTMINMAX
# ifdef __SIGRTMIN
	signals[__SIGRTMIN] = "RTMIN";
# endif
// This makes array about x2 bigger.
// More compact approach is to special-case SIGRTMAX in print_signames()
//# ifdef __SIGRTMAX
//	signals[__SIGRTMAX] = "RTMAX";
//# endif
#endif

	signals_initialized = 1;
}

// Convert signal name to number.

int FAST_FUNC get_signum(const char *name)
{
	unsigned i;

	initialize_signals();
	i = bb_strtou(name, NULL, 10);
	if (!errno)
		return i;
	if (strncasecmp(name, "SIG", 3) == 0)
		name += 3;
	for (i = 0; i < ARRAY_SIZE(signals); i++)
		if (strcasecmp(name, signals[i]) == 0)
			return i;

#if ENABLE_DESKTOP
# if defined(SIGIOT) || defined(SIGIO)
	/* SIGIO[T] are aliased to other names,
	 * thus cannot be stored in the signals[] array.
	 * Need special code to recognize them */
	if ((name[0] | 0x20) == 'i' && (name[1] | 0x20) == 'o') {
#  ifdef SIGIO
		if (!name[2])
			return SIGIO;
#  endif
#  ifdef SIGIOT
		if ((name[2] | 0x20) == 't' && !name[3])
			return SIGIOT;
#  endif
	}
# endif
#endif

#if ENABLE_FEATURE_RTMINMAX
# if defined(SIGRTMIN) && defined(SIGRTMAX)
/* libc may use some rt sigs for pthreads and therefore "remap" SIGRTMIN/MAX,
 * but we want to use "raw" SIGRTMIN/MAX. Underscored names, if exist, provide
 * them. If they don't exist, fall back to non-underscored ones: */
#  if !defined(__SIGRTMIN)
#   define __SIGRTMIN SIGRTMIN
#  endif
#  if !defined(__SIGRTMAX)
#   define __SIGRTMAX SIGRTMAX
#  endif
	if (strncasecmp(name, "RTMIN", 5) == 0) {
		if (!name[5])
			return __SIGRTMIN;
		if (name[5] == '+') {
			i = bb_strtou(name + 6, NULL, 10);
			if (!errno && i <= __SIGRTMAX - __SIGRTMIN)
				return __SIGRTMIN + i;
		}
	}
	else if (strncasecmp(name, "RTMAX", 5) == 0) {
		if (!name[5])
			return __SIGRTMAX;
		if (name[5] == '-') {
			i = bb_strtou(name + 6, NULL, 10);
			if (!errno && i <= __SIGRTMAX - __SIGRTMIN)
				return __SIGRTMAX - i;
		}
	}
# endif
#endif

	return -1;
}

// Convert signal number to name

const char* FAST_FUNC get_signame(int number)
{
	initialize_signals();
	if ((unsigned)number < ARRAY_SIZE(signals)) {
		if (signals[number][0]) /* if it's not an empty str */
			return signals[number];
	}

	return itoa(number);
}


// Print the whole signal list

void FAST_FUNC print_signames(void)
{
	unsigned signo;

	initialize_signals();
	for (signo = 1; signo < ARRAY_SIZE(signals); signo++) {
		const char *name = signals[signo];
		if (name[0])
			printf("%2u) %s\n", signo, name);
	}
#if ENABLE_FEATURE_RTMINMAX
# ifdef __SIGRTMAX
	printf("%2u) %s\n", __SIGRTMAX, "RTMAX");
# endif
#endif
}