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  * 4. 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  * @(#)error.c  8.2 (Berkeley) 5/4/95
  33  * $FreeBSD: head/bin/sh/error.c 216622 2010-12-21 20:47:06Z jilles $
  34  */
  35
  36 /*
  37  * Errors and exceptions.
  38  */
  39
  40 #include "shell.h"
  41 #include "main.h"
  42 #include "options.h"
  43 #include "output.h"
  44 #include "error.h"
  45 #include "eval.h"  /* defines commandname */
  46 #include "nodes.h" /* show.h needs nodes.h */
  47 #include "show.h"
  48 #include "trap.h"
  49 #include <signal.h>
  50 #include <stdlib.h>
  51 #include <unistd.h>
  52 #include <errno.h>
  53
  54
  55 /*
  56  * Code to handle exceptions in C.
  57  */
  58
  59 struct jmploc *handler;
  60 volatile sig_atomic_t exception;
  61 volatile sig_atomic_t suppressint;
  62 volatile sig_atomic_t intpending;
  63
  64
  65 static void exverror(int, const char *, va_list) __printf0like(2, 0) __dead2;
  66
  67 /*
  68  * Called to raise an exception.  Since C doesn't include exceptions, we
  69  * just do a longjmp to the exception handler.  The type of exception is
  70  * stored in the global variable "exception".
  71  *
  72  * Interrupts are disabled; they should be reenabled when the exception is
  73  * caught.
  74  */
  75
  76 void
  77 exraise(int e)
  78 {
  79         INTOFF;
  80         if (handler == NULL)
  81                 abort();
  82         exception = e;
  83         longjmp(handler->loc, 1);
  84 }
  85
  86
  87 /*
  88  * Called from trap.c when a SIGINT is received.  (If the user specifies
  89  * that SIGINT is to be trapped or ignored using the trap builtin, then
  90  * this routine is not called.)  Suppressint is nonzero when interrupts
  91  * are held using the INTOFF macro.  If SIGINTs are not suppressed and
  92  * the shell is not a root shell, then we want to be terminated if we
  93  * get here, as if we were terminated directly by a SIGINT.  Arrange for
  94  * this here.
  95  */
  96
  97 void
  98 onint(void)
  99 {
 100         sigset_t sigs;
 101
 102         /*
 103          * The !in_dotrap here is safe.  The only way we can arrive here
 104          * with in_dotrap set is that a trap handler set SIGINT to SIG_DFL
 105          * and killed itself.
 106          */
 107
 108         if (suppressint && !in_dotrap) {
 109                 intpending++;
 110                 return;
 111         }
 112         intpending = 0;
 113         sigemptyset(&sigs);
 114         sigprocmask(SIG_SETMASK, &sigs, NULL);
 115
 116         /*
 117          * This doesn't seem to be needed, since main() emits a newline.
 118          */
 119 #if 0
 120         if (tcgetpgrp(0) == getpid())
 121                 write(STDERR_FILENO, "\n", 1);
 122 #endif
 123         if (rootshell && iflag)
 124                 exraise(EXINT);
 125         else {
 126                 signal(SIGINT, SIG_DFL);
 127                 kill(getpid(), SIGINT);
 128         }
 129 }
 130
 131
 132 static void
 133 vwarning(const char *msg, va_list ap)
 134 {
 135         if (commandname)
 136                 outfmt(out2, "%s: ", commandname);
 137         doformat(out2, msg, ap);
 138         out2fmt_flush("\n");
 139 }
 140
 141
 142 void
 143 warning(const char *msg, ...)
 144 {
 145         va_list ap;
 146         va_start(ap, msg);
 147         vwarning(msg, ap);
 148         va_end(ap);
 149 }
 150
 151
 152 /*
 153  * Exverror is called to raise the error exception.  If the first argument
 154  * is not NULL then error prints an error message using printf style
 155  * formatting.  It then raises the error exception.
 156  */
 157 static void
 158 exverror(int cond, const char *msg, va_list ap)
 159 {
 160         /*
 161          * An interrupt trumps an error.  Certain places catch error
 162          * exceptions or transform them to a plain nonzero exit code
 163          * in child processes, and if an error exception can be handled,
 164          * an interrupt can be handled as well.
 165          *
 166          * exraise() will disable interrupts for the exception handler.
 167          */
 168         FORCEINTON;
 169
 170 #ifdef DEBUG
 171         if (msg)
 172                 TRACE(("exverror(%d, \"%s\") pid=%d\n", cond, msg, getpid()));
 173         else
 174                 TRACE(("exverror(%d, NULL) pid=%d\n", cond, getpid()));
 175 #endif
 176         if (msg)
 177                 vwarning(msg, ap);
 178         flushall();
 179         exraise(cond);
 180 }
 181
 182
 183 void
 184 error(const char *msg, ...)
 185 {
 186         va_list ap;
 187         va_start(ap, msg);
 188         exverror(EXERROR, msg, ap);
 189         va_end(ap);
 190 }
 191
 192
 193 void
 194 exerror(int cond, const char *msg, ...)
 195 {
 196         va_list ap;
 197         va_start(ap, msg);
 198         exverror(cond, msg, ap);
 199         va_end(ap);
 200 }