/*      $NetBSD: error.c,v 1.45 2023/03/19 17:55:57 kre Exp $   */

/*-
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)error.c     8.2 (Berkeley) 5/4/95";
#else
__RCSID("$NetBSD: error.c,v 1.45 2023/03/19 17:55:57 kre Exp $");
#endif
#endif /* not lint */

/*
 * Errors and exceptions.
 */

#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

#include "shell.h"
#include "eval.h" /* for commandname */
#include "main.h"
#include "options.h"
#include "output.h"
#include "error.h"
#include "show.h"


/*
 * Code to handle exceptions in C.
 */

struct jmploc *handler;
int exception;
volatile int suppressint;
volatile int intpending;
volatile int errors_suppressed;
const char * volatile currentcontext;



static void exverror(int, const char *, va_list) __dead;

/*
 * Called to raise an exception.  Since C doesn't include exceptions, we
 * just do a longjmp to the exception handler.  The type of exception is
 * stored in the global variable "exception".
 */

void
exraise(int e)
{
        CTRACE(DBG_ERRS, ("exraise(%d)\n", e));
        if (handler == NULL)
                abort();
        exception = e;
        longjmp(handler->loc, 1);
}


/*
 * Called from trap.c when a SIGINT is received.  (If the user specifies
 * that SIGINT is to be trapped or ignored using the trap builtin, then
 * this routine is not called.)  Suppressint is nonzero when interrupts
 * are held using the INTOFF macro.  The call to _exit is necessary because
 * there is a short period after a fork before the signal handlers are
 * set to the appropriate value for the child.  (The test for iflag is
 * just defensive programming.)
 */

void
onint(void)
{
        sigset_t nsigset;

        if (suppressint) {
                intpending = 1;
                return;
        }
        intpending = 0;
        sigemptyset(&nsigset);
        sigprocmask(SIG_SETMASK, &nsigset, NULL);
        if (rootshell && iflag)
                exraise(EXINT);
        else {
                signal(SIGINT, SIG_DFL);
                raise(SIGINT);
        }
        /* NOTREACHED */
}

static __printflike(2, 0) void
exvwarning(int sv_errno, const char *msg, va_list ap)
{
        /* Partially emulate line buffered output so that:
         *      printf '%d\n' 1 a 2
         * and
         *      printf '%d %d %d\n' 1 a 2
         * both generate sensible text when stdout and stderr are merged.
         */
        if (output.buf != NULL && output.nextc != output.buf &&
            output.nextc[-1] == '\n')
                flushout(&output);

        if (errors_suppressed)
                return;

        if (commandname)
                outfmt(&errout, "%s: ", commandname);
        else
                outfmt(&errout, "%s: ", getprogname());
        if (currentcontext != NULL)
                outfmt(&errout, "%s: ", currentcontext);
        if (msg != NULL) {
                doformat(&errout, msg, ap);
                if (sv_errno >= 0)
                        outfmt(&errout, ": ");
        }
        if (sv_errno >= 0)
                outfmt(&errout, "%s", strerror(sv_errno));
        out2c('\n');
        flushout(&errout);
}

/*
 * Exverror is called to raise the error exception.  If the second argument
 * is not NULL then error prints an error message using printf style
 * formatting.  It then raises the error exception.
 */
static __printflike(2, 0) void
exverror(int cond, const char *msg, va_list ap)
{
        CLEAR_PENDING_INT;
        INTOFF;

#ifdef DEBUG
        if (msg) {
                CTRACE(DBG_ERRS, ("exverror(%d, \"", cond));
                CTRACEV(DBG_ERRS, (msg, ap));
                CTRACE(DBG_ERRS, ("\") pid=%d\n", getpid()));
        } else
                CTRACE(DBG_ERRS, ("exverror(%d, NULL) pid=%d\n", cond,
                    getpid()));
#endif
        if (msg)
                exvwarning(-1, msg, ap);

        flushall();
        exraise(cond);
        /* NOTREACHED */
}


void
error(const char *msg, ...)
{
        va_list ap;

        /*
         * On error, we certainly never want exit(0)...
         */
        if (exerrno == 0)
                exerrno = 1;
        va_start(ap, msg);
        exverror(EXERROR, msg, ap);
        /* NOTREACHED */
        va_end(ap);
}


void
exerror(int cond, const char *msg, ...)
{
        va_list ap;

        va_start(ap, msg);
        exverror(cond, msg, ap);
        /* NOTREACHED */
        va_end(ap);
}

/*
 * error/warning routines for external builtins
 */

void
sh_exit(int rval)
{
        VTRACE(DBG_ERRS|DBG_PROCS|DBG_CMDS, ("sh_exit(%d)\n", rval));
        exerrno = rval & 255;
        exraise(EXEXEC);
}

void
sh_err(int status, const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        exvwarning(errno, fmt, ap);
        va_end(ap);
        sh_exit(status);
}

void
sh_verr(int status, const char *fmt, va_list ap)
{
        exvwarning(errno, fmt, ap);
        sh_exit(status);
}

void
sh_errx(int status, const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        exvwarning(-1, fmt, ap);
        va_end(ap);
        sh_exit(status);
}

void
sh_verrx(int status, const char *fmt, va_list ap)
{
        exvwarning(-1, fmt, ap);
        sh_exit(status);
}

void
sh_warn(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        exvwarning(errno, fmt, ap);
        va_end(ap);
}

void
sh_vwarn(const char *fmt, va_list ap)
{
        exvwarning(errno, fmt, ap);
}

void
sh_warnx(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        exvwarning(-1, fmt, ap);
        va_end(ap);
}

void
sh_vwarnx(const char *fmt, va_list ap)
{
        exvwarning(-1, fmt, ap);
}


/*
 * Table of error messages.
 */

struct errname {
        short errcode;          /* error number */
        short action;           /* operation which encountered the error */
        const char *msg;        /* text describing the error */
};


#define ALL (E_OPEN|E_CREAT|E_EXEC)

STATIC const struct errname errormsg[] = {
        { EINTR,        ALL,    "interrupted" },
        { EACCES,       E_EXEC, "no execute permission" },
        { EACCES,       ALL,    "permission denied" },
        { EIO,          ALL,    "I/O error" },
        { EEXIST,       ALL,    "file exists" },
        { ENOENT,       E_OPEN, "no such file" },
        { ENOENT,       E_CREAT,"directory nonexistent" },
        { ENOENT,       E_EXEC, "not found" },
        { ENOTDIR,      E_OPEN, "no such file" },
        { ENOTDIR,      E_CREAT,"directory nonexistent" },
        { ENOTDIR,      E_EXEC, "not found" },
        { EISDIR,       ALL,    "is a directory" },
#ifdef EMFILE
        { EMFILE,       ALL,    "too many open files" },
#endif
        { ENFILE,       ALL,    "file table overflow" },
        { ENOSPC,       ALL,    "file system full" },
#ifdef EDQUOT
        { EDQUOT,       ALL,    "disk quota exceeded" },
#endif
#ifdef ENOSR
        { ENOSR,        ALL,    "no streams resources" },
#endif
        { ENXIO,        ALL,    "no such device or address" },
        { EROFS,        ALL,    "read-only file system" },
        { ETXTBSY,      ALL,    "text busy" },
#ifdef EAGAIN
        { EAGAIN,       E_EXEC, "not enough memory" },
#endif
        { ENOMEM,       ALL,    "not enough memory" },
#ifdef ENOLINK
        { ENOLINK,      ALL,    "remote access failed" },
#endif
#ifdef EMULTIHOP
        { EMULTIHOP,    ALL,    "remote access failed" },
#endif
#ifdef ECOMM
        { ECOMM,        ALL,    "remote access failed" },
#endif
#ifdef ESTALE
        { ESTALE,       ALL,    "remote access failed" },
#endif
#ifdef ETIMEDOUT
        { ETIMEDOUT,    ALL,    "remote access failed" },
#endif
#ifdef ELOOP
        { ELOOP,        ALL,    "symbolic link loop" },
#endif
#ifdef ENAMETOOLONG
        { ENAMETOOLONG, ALL,    "file name too long" },
#endif
        { E2BIG,        E_EXEC, "argument list too long" },
#ifdef ELIBACC
        { ELIBACC,      E_EXEC, "shared library missing" },
#endif
        { 0,            0,      NULL },
};


/*
 * Return a string describing an error.  The returned string may be a
 * pointer to a static buffer that will be overwritten on the next call.
 * Action describes the operation that got the error.
 */

const char *
errmsg(int e, int action)
{
        struct errname const *ep;
        static char buf[12];

        for (ep = errormsg ; ep->errcode ; ep++) {
                if (ep->errcode == e && (ep->action & action) != 0)
                        return ep->msg;
        }
        fmtstr(buf, sizeof buf, "error %d", e);
        return buf;
}