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gcc/libiberty/strsignal.c
Jeff Law 3affd5f0f4 Update from Cygnus libiberty.
libiberty uses autoconf now.

From-SVN: r19791
1998-05-15 17:42:58 -06:00

645 lines
15 KiB
C

/* Extended support for using signal values.
Written by Fred Fish. fnf@cygnus.com
This file is in the public domain. */
#include "ansidecl.h"
#include "libiberty.h"
#include "config.h"
/* We need to declare sys_siglist, because even if the system provides
it we can't assume that it is declared in <signal.h> (for example,
SunOS provides sys_siglist, but it does not declare it in any
header file). fHowever, we can't declare sys_siglist portably,
because on some systems it is declared with const and on some
systems it is declared without const. If we were using autoconf,
we could work out the right declaration. Until, then we just
ignore any declaration in the system header files, and always
declare it ourselves. With luck, this will always work. */
#define sys_siglist no_such_symbol
#include <stdio.h>
#include <signal.h>
/* Routines imported from standard C runtime libraries. */
#ifdef __STDC__
#include <stddef.h>
extern void *malloc (size_t size); /* 4.10.3.3 */
extern void *memset (void *s, int c, size_t n); /* 4.11.6.1 */
#else /* !__STDC__ */
extern char *malloc (); /* Standard memory allocater */
extern char *memset ();
#endif /* __STDC__ */
/* Undefine the macro we used to hide the definition of sys_siglist
found in the system header files. */
#undef sys_siglist
#ifndef NULL
# ifdef __STDC__
# define NULL (void *) 0
# else
# define NULL 0
# endif
#endif
#ifndef MAX
# define MAX(a,b) ((a) > (b) ? (a) : (b))
#endif
static void init_signal_tables PARAMS ((void));
/* Translation table for signal values.
Note that this table is generally only accessed when it is used at runtime
to initialize signal name and message tables that are indexed by signal
value.
Not all of these signals will exist on all systems. This table is the only
thing that should have to be updated as new signal numbers are introduced.
It's sort of ugly, but at least its portable. */
struct signal_info
{
int value; /* The numeric value from <signal.h> */
const char *name; /* The equivalent symbolic value */
#ifndef HAVE_SYS_SIGLIST
const char *msg; /* Short message about this value */
#endif
};
#ifndef HAVE_SYS_SIGLIST
# define ENTRY(value, name, msg) {value, name, msg}
#else
# define ENTRY(value, name, msg) {value, name}
#endif
static const struct signal_info signal_table[] =
{
#if defined (SIGHUP)
ENTRY(SIGHUP, "SIGHUP", "Hangup"),
#endif
#if defined (SIGINT)
ENTRY(SIGINT, "SIGINT", "Interrupt"),
#endif
#if defined (SIGQUIT)
ENTRY(SIGQUIT, "SIGQUIT", "Quit"),
#endif
#if defined (SIGILL)
ENTRY(SIGILL, "SIGILL", "Illegal instruction"),
#endif
#if defined (SIGTRAP)
ENTRY(SIGTRAP, "SIGTRAP", "Trace/breakpoint trap"),
#endif
/* Put SIGIOT before SIGABRT, so that if SIGIOT==SIGABRT then SIGABRT
overrides SIGIOT. SIGABRT is in ANSI and POSIX.1, and SIGIOT isn't. */
#if defined (SIGIOT)
ENTRY(SIGIOT, "SIGIOT", "IOT trap"),
#endif
#if defined (SIGABRT)
ENTRY(SIGABRT, "SIGABRT", "Aborted"),
#endif
#if defined (SIGEMT)
ENTRY(SIGEMT, "SIGEMT", "Emulation trap"),
#endif
#if defined (SIGFPE)
ENTRY(SIGFPE, "SIGFPE", "Arithmetic exception"),
#endif
#if defined (SIGKILL)
ENTRY(SIGKILL, "SIGKILL", "Killed"),
#endif
#if defined (SIGBUS)
ENTRY(SIGBUS, "SIGBUS", "Bus error"),
#endif
#if defined (SIGSEGV)
ENTRY(SIGSEGV, "SIGSEGV", "Segmentation fault"),
#endif
#if defined (SIGSYS)
ENTRY(SIGSYS, "SIGSYS", "Bad system call"),
#endif
#if defined (SIGPIPE)
ENTRY(SIGPIPE, "SIGPIPE", "Broken pipe"),
#endif
#if defined (SIGALRM)
ENTRY(SIGALRM, "SIGALRM", "Alarm clock"),
#endif
#if defined (SIGTERM)
ENTRY(SIGTERM, "SIGTERM", "Terminated"),
#endif
#if defined (SIGUSR1)
ENTRY(SIGUSR1, "SIGUSR1", "User defined signal 1"),
#endif
#if defined (SIGUSR2)
ENTRY(SIGUSR2, "SIGUSR2", "User defined signal 2"),
#endif
/* Put SIGCLD before SIGCHLD, so that if SIGCLD==SIGCHLD then SIGCHLD
overrides SIGCLD. SIGCHLD is in POXIX.1 */
#if defined (SIGCLD)
ENTRY(SIGCLD, "SIGCLD", "Child status changed"),
#endif
#if defined (SIGCHLD)
ENTRY(SIGCHLD, "SIGCHLD", "Child status changed"),
#endif
#if defined (SIGPWR)
ENTRY(SIGPWR, "SIGPWR", "Power fail/restart"),
#endif
#if defined (SIGWINCH)
ENTRY(SIGWINCH, "SIGWINCH", "Window size changed"),
#endif
#if defined (SIGURG)
ENTRY(SIGURG, "SIGURG", "Urgent I/O condition"),
#endif
#if defined (SIGIO)
/* "I/O pending" has also been suggested, but is misleading since the
signal only happens when the process has asked for it, not everytime
I/O is pending. */
ENTRY(SIGIO, "SIGIO", "I/O possible"),
#endif
#if defined (SIGPOLL)
ENTRY(SIGPOLL, "SIGPOLL", "Pollable event occurred"),
#endif
#if defined (SIGSTOP)
ENTRY(SIGSTOP, "SIGSTOP", "Stopped (signal)"),
#endif
#if defined (SIGTSTP)
ENTRY(SIGTSTP, "SIGTSTP", "Stopped (user)"),
#endif
#if defined (SIGCONT)
ENTRY(SIGCONT, "SIGCONT", "Continued"),
#endif
#if defined (SIGTTIN)
ENTRY(SIGTTIN, "SIGTTIN", "Stopped (tty input)"),
#endif
#if defined (SIGTTOU)
ENTRY(SIGTTOU, "SIGTTOU", "Stopped (tty output)"),
#endif
#if defined (SIGVTALRM)
ENTRY(SIGVTALRM, "SIGVTALRM", "Virtual timer expired"),
#endif
#if defined (SIGPROF)
ENTRY(SIGPROF, "SIGPROF", "Profiling timer expired"),
#endif
#if defined (SIGXCPU)
ENTRY(SIGXCPU, "SIGXCPU", "CPU time limit exceeded"),
#endif
#if defined (SIGXFSZ)
ENTRY(SIGXFSZ, "SIGXFSZ", "File size limit exceeded"),
#endif
#if defined (SIGWIND)
ENTRY(SIGWIND, "SIGWIND", "SIGWIND"),
#endif
#if defined (SIGPHONE)
ENTRY(SIGPHONE, "SIGPHONE", "SIGPHONE"),
#endif
#if defined (SIGLOST)
ENTRY(SIGLOST, "SIGLOST", "Resource lost"),
#endif
#if defined (SIGWAITING)
ENTRY(SIGWAITING, "SIGWAITING", "Process's LWPs are blocked"),
#endif
#if defined (SIGLWP)
ENTRY(SIGLWP, "SIGLWP", "Signal LWP"),
#endif
#if defined (SIGDANGER)
ENTRY(SIGDANGER, "SIGDANGER", "Swap space dangerously low"),
#endif
#if defined (SIGGRANT)
ENTRY(SIGGRANT, "SIGGRANT", "Monitor mode granted"),
#endif
#if defined (SIGRETRACT)
ENTRY(SIGRETRACT, "SIGRETRACT", "Need to relinguish monitor mode"),
#endif
#if defined (SIGMSG)
ENTRY(SIGMSG, "SIGMSG", "Monitor mode data available"),
#endif
#if defined (SIGSOUND)
ENTRY(SIGSOUND, "SIGSOUND", "Sound completed"),
#endif
#if defined (SIGSAK)
ENTRY(SIGSAK, "SIGSAK", "Secure attention"),
#endif
ENTRY(0, NULL, NULL)
};
/* Translation table allocated and initialized at runtime. Indexed by the
signal value to find the equivalent symbolic value. */
static const char **signal_names;
static int num_signal_names = 0;
/* Translation table allocated and initialized at runtime, if it does not
already exist in the host environment. Indexed by the signal value to find
the descriptive string.
We don't export it for use in other modules because even though it has the
same name, it differs from other implementations in that it is dynamically
initialized rather than statically initialized. */
#ifndef HAVE_SYS_SIGLIST
static int sys_nsig;
static const char **sys_siglist;
#else
#ifdef NSIG
static int sys_nsig = NSIG;
#else
#ifdef _NSIG
static int sys_nsig = _NSIG;
#endif
#endif
extern const char * const sys_siglist[];
#endif
/*
NAME
init_signal_tables -- initialize the name and message tables
SYNOPSIS
static void init_signal_tables ();
DESCRIPTION
Using the signal_table, which is initialized at compile time, generate
the signal_names and the sys_siglist (if needed) tables, which are
indexed at runtime by a specific signal value.
BUGS
The initialization of the tables may fail under low memory conditions,
in which case we don't do anything particularly useful, but we don't
bomb either. Who knows, it might succeed at a later point if we free
some memory in the meantime. In any case, the other routines know
how to deal with lack of a table after trying to initialize it. This
may or may not be considered to be a bug, that we don't specifically
warn about this particular failure mode.
*/
static void
init_signal_tables ()
{
const struct signal_info *eip;
int nbytes;
/* If we haven't already scanned the signal_table once to find the maximum
signal value, then go find it now. */
if (num_signal_names == 0)
{
for (eip = signal_table; eip -> name != NULL; eip++)
{
if (eip -> value >= num_signal_names)
{
num_signal_names = eip -> value + 1;
}
}
}
/* Now attempt to allocate the signal_names table, zero it out, and then
initialize it from the statically initialized signal_table. */
if (signal_names == NULL)
{
nbytes = num_signal_names * sizeof (char *);
if ((signal_names = (const char **) malloc (nbytes)) != NULL)
{
memset (signal_names, 0, nbytes);
for (eip = signal_table; eip -> name != NULL; eip++)
{
signal_names[eip -> value] = eip -> name;
}
}
}
#ifndef HAVE_SYS_SIGLIST
/* Now attempt to allocate the sys_siglist table, zero it out, and then
initialize it from the statically initialized signal_table. */
if (sys_siglist == NULL)
{
nbytes = num_signal_names * sizeof (char *);
if ((sys_siglist = (const char **) malloc (nbytes)) != NULL)
{
memset (sys_siglist, 0, nbytes);
sys_nsig = num_signal_names;
for (eip = signal_table; eip -> name != NULL; eip++)
{
sys_siglist[eip -> value] = eip -> msg;
}
}
}
#endif
}
/*
NAME
signo_max -- return the max signo value
SYNOPSIS
int signo_max ();
DESCRIPTION
Returns the maximum signo value for which a corresponding symbolic
name or message is available. Note that in the case where
we use the sys_siglist supplied by the system, it is possible for
there to be more symbolic names than messages, or vice versa.
In fact, the manual page for psignal(3b) explicitly warns that one
should check the size of the table (NSIG) before indexing it,
since new signal codes may be added to the system before they are
added to the table. Thus NSIG might be smaller than value
implied by the largest signo value defined in <signal.h>.
We return the maximum value that can be used to obtain a meaningful
symbolic name or message.
*/
int
signo_max ()
{
int maxsize;
if (signal_names == NULL)
{
init_signal_tables ();
}
maxsize = MAX (sys_nsig, num_signal_names);
return (maxsize - 1);
}
/*
NAME
strsignal -- map a signal number to a signal message string
SYNOPSIS
const char *strsignal (int signo)
DESCRIPTION
Maps an signal number to an signal message string, the contents of
which are implementation defined. On systems which have the external
variable sys_siglist, these strings will be the same as the ones used
by psignal().
If the supplied signal number is within the valid range of indices
for the sys_siglist, but no message is available for the particular
signal number, then returns the string "Signal NUM", where NUM is the
signal number.
If the supplied signal number is not a valid index into sys_siglist,
returns NULL.
The returned string is only guaranteed to be valid only until the
next call to strsignal.
*/
#ifndef HAVE_STRSIGNAL
const char *
strsignal (signo)
int signo;
{
const char *msg;
static char buf[32];
#ifndef HAVE_SYS_SIGLIST
if (signal_names == NULL)
{
init_signal_tables ();
}
#endif
if ((signo < 0) || (signo >= sys_nsig))
{
/* Out of range, just return NULL */
msg = NULL;
}
else if ((sys_siglist == NULL) || (sys_siglist[signo] == NULL))
{
/* In range, but no sys_siglist or no entry at this index. */
sprintf (buf, "Signal %d", signo);
msg = (const char *) buf;
}
else
{
/* In range, and a valid message. Just return the message. */
msg = (const char *) sys_siglist[signo];
}
return (msg);
}
#endif /* ! HAVE_STRSIGNAL */
/*
NAME
strsigno -- map an signal number to a symbolic name string
SYNOPSIS
const char *strsigno (int signo)
DESCRIPTION
Given an signal number, returns a pointer to a string containing
the symbolic name of that signal number, as found in <signal.h>.
If the supplied signal number is within the valid range of indices
for symbolic names, but no name is available for the particular
signal number, then returns the string "Signal NUM", where NUM is
the signal number.
If the supplied signal number is not within the range of valid
indices, then returns NULL.
BUGS
The contents of the location pointed to are only guaranteed to be
valid until the next call to strsigno.
*/
const char *
strsigno (signo)
int signo;
{
const char *name;
static char buf[32];
if (signal_names == NULL)
{
init_signal_tables ();
}
if ((signo < 0) || (signo >= num_signal_names))
{
/* Out of range, just return NULL */
name = NULL;
}
else if ((signal_names == NULL) || (signal_names[signo] == NULL))
{
/* In range, but no signal_names or no entry at this index. */
sprintf (buf, "Signal %d", signo);
name = (const char *) buf;
}
else
{
/* In range, and a valid name. Just return the name. */
name = signal_names[signo];
}
return (name);
}
/*
NAME
strtosigno -- map a symbolic signal name to a numeric value
SYNOPSIS
int strtosigno (char *name)
DESCRIPTION
Given the symbolic name of a signal, map it to a signal number.
If no translation is found, returns 0.
*/
int
strtosigno (name)
const char *name;
{
int signo = 0;
if (name != NULL)
{
if (signal_names == NULL)
{
init_signal_tables ();
}
for (signo = 0; signo < num_signal_names; signo++)
{
if ((signal_names[signo] != NULL) &&
(strcmp (name, signal_names[signo]) == 0))
{
break;
}
}
if (signo == num_signal_names)
{
signo = 0;
}
}
return (signo);
}
/*
NAME
psignal -- print message about signal to stderr
SYNOPSIS
void psignal (unsigned signo, char *message);
DESCRIPTION
Print to the standard error the message, followed by a colon,
followed by the description of the signal specified by signo,
followed by a newline.
*/
#ifndef HAVE_PSIGNAL
void
psignal (signo, message)
unsigned signo;
char *message;
{
if (signal_names == NULL)
{
init_signal_tables ();
}
if ((signo <= 0) || (signo >= sys_nsig))
{
fprintf (stderr, "%s: unknown signal\n", message);
}
else
{
fprintf (stderr, "%s: %s\n", message, sys_siglist[signo]);
}
}
#endif /* ! HAVE_PSIGNAL */
/* A simple little main that does nothing but print all the signal translations
if MAIN is defined and this file is compiled and linked. */
#ifdef MAIN
#include <stdio.h>
int
main ()
{
int signo;
int maxsigno;
const char *name;
const char *msg;
maxsigno = signo_max ();
printf ("%d entries in names table.\n", num_signal_names);
printf ("%d entries in messages table.\n", sys_nsig);
printf ("%d is max useful index.\n", maxsigno);
/* Keep printing values until we get to the end of *both* tables, not
*either* table. Note that knowing the maximum useful index does *not*
relieve us of the responsibility of testing the return pointer for
NULL. */
for (signo = 0; signo <= maxsigno; signo++)
{
name = strsigno (signo);
name = (name == NULL) ? "<NULL>" : name;
msg = strsignal (signo);
msg = (msg == NULL) ? "<NULL>" : msg;
printf ("%-4d%-18s%s\n", signo, name, msg);
}
return 0;
}
#endif