bin/sh/error.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Kenneth Almquist.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)error.c     8.2 (Berkeley) 5/4/95";
  36 #endif
  37 #endif /* not lint */
  38 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD: head/bin/sh/error.c 340284 2018-11-09 14:58:24Z jilles $");
  40
  41 /*
  42  * Errors and exceptions.
  43  */
  44
  45 #include "shell.h"
  46 #include "eval.h"
  47 #include "main.h"
  48 #include "options.h"
  49 #include "output.h"
  50 #include "error.h"
  51 #include "nodes.h" /* show.h needs nodes.h */
  52 #include "show.h"
  53 #include "trap.h"
  54 #include <signal.h>
  55 #include <stdlib.h>
  56 #include <unistd.h>
  57 #include <errno.h>
  58
  59
  60 /*
  61  * Code to handle exceptions in C.
  62  */
  63
  64 struct jmploc *handler;
  65 volatile sig_atomic_t exception;
  66 volatile sig_atomic_t suppressint;
  67 volatile sig_atomic_t intpending;
  68
  69
  70 static void verrorwithstatus(int, const char *, va_list) __printf0like(2, 0) __dead2;
  71
  72 /*
  73  * Called to raise an exception.  Since C doesn't include exceptions, we
  74  * just do a longjmp to the exception handler.  The type of exception is
  75  * stored in the global variable "exception".
  76  *
  77  * Interrupts are disabled; they should be reenabled when the exception is
  78  * caught.
  79  */
  80
  81 void
  82 exraise(int e)
  83 {
  84         INTOFF;
  85         if (handler == NULL)
  86                 abort();
  87         exception = e;
  88         longjmp(handler->loc, 1);
  89 }
  90
  91
  92 /*
  93  * Called from trap.c when a SIGINT is received and not suppressed, or when
  94  * an interrupt is pending and interrupts are re-enabled using INTON.
  95  * (If the user specifies that SIGINT is to be trapped or ignored using the
  96  * trap builtin, then this routine is not called.)  Suppressint is nonzero
  97  * when interrupts are held using the INTOFF macro.  If SIGINTs are not
  98  * suppressed and the shell is not a root shell, then we want to be
  99  * terminated if we get here, as if we were terminated directly by a SIGINT.
 100  * Arrange for this here.
 101  */
 102
 103 void
 104 onint(void)
 105 {
 106         sigset_t sigs;
 107
 108         intpending = 0;
 109         sigemptyset(&sigs);
 110         sigprocmask(SIG_SETMASK, &sigs, NULL);
 111
 112         /*
 113          * This doesn't seem to be needed, since main() emits a newline.
 114          */
 115 #if 0
 116         if (tcgetpgrp(0) == getpid())
 117                 write(STDERR_FILENO, "\n", 1);
 118 #endif
 119         if (rootshell && iflag)
 120                 exraise(EXINT);
 121         else {
 122                 signal(SIGINT, SIG_DFL);
 123                 kill(getpid(), SIGINT);
 124                 _exit(128 + SIGINT);
 125         }
 126 }
 127
 128
 129 static void
 130 vwarning(const char *msg, va_list ap)
 131 {
 132         if (commandname)
 133                 outfmt(out2, "%s: ", commandname);
 134         else if (arg0)
 135                 outfmt(out2, "%s: ", arg0);
 136         doformat(out2, msg, ap);
 137         out2fmt_flush("\n");
 138 }
 139
 140
 141 void
 142 warning(const char *msg, ...)
 143 {
 144         va_list ap;
 145         va_start(ap, msg);
 146         vwarning(msg, ap);
 147         va_end(ap);
 148 }
 149
 150
 151 /*
 152  * Exverror is called to raise the error exception.  If the first argument
 153  * is not NULL then error prints an error message using printf style
 154  * formatting.  It then raises the error exception.
 155  */
 156 static void
 157 verrorwithstatus(int status, const char *msg, va_list ap)
 158 {
 159         /*
 160          * An interrupt trumps an error.  Certain places catch error
 161          * exceptions or transform them to a plain nonzero exit code
 162          * in child processes, and if an error exception can be handled,
 163          * an interrupt can be handled as well.
 164          *
 165          * exraise() will disable interrupts for the exception handler.
 166          */
 167         FORCEINTON;
 168
 169 #ifdef DEBUG
 170         if (msg)
 171                 TRACE(("verrorwithstatus(%d, \"%s\") pid=%d\n",
 172                     status, msg, getpid()));
 173         else
 174                 TRACE(("verrorwithstatus(%d, NULL) pid=%d\n",
 175                     status, getpid()));
 176 #endif
 177         if (msg)
 178                 vwarning(msg, ap);
 179         flushall();
 180         exitstatus = status;
 181         exraise(EXERROR);
 182 }
 183
 184
 185 void
 186 error(const char *msg, ...)
 187 {
 188         va_list ap;
 189         va_start(ap, msg);
 190         verrorwithstatus(2, msg, ap);
 191         va_end(ap);
 192 }
 193
 194
 195 void
 196 errorwithstatus(int status, const char *msg, ...)
 197 {
 198         va_list ap;
 199         va_start(ap, msg);
 200         verrorwithstatus(status, msg, ap);
 201         va_end(ap);
 202 }