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/*
34 * Errors and exceptions.
35 */
36
37#include "shell.h"
38#include "eval.h"
39#include "main.h"
40#include "options.h"
41#include "output.h"
42#include "error.h"
43#include "nodes.h" /* show.h needs nodes.h */
44#include "show.h"
45#include "trap.h"
46#include <signal.h>
47#include <stdlib.h>
48#include <unistd.h>
49#include <errno.h>
50
51
52/*
53 * Code to handle exceptions in C.
54 */
55
56struct jmploc *handler;
57volatile sig_atomic_t exception;
58volatile sig_atomic_t suppressint;
59volatile sig_atomic_t intpending;
60
61
62static void verrorwithstatus(int, const char *, va_list) __printf0like(2, 0) __dead2;
63
64/*
65 * Called to raise an exception.  Since C doesn't include exceptions, we
66 * just do a longjmp to the exception handler.  The type of exception is
67 * stored in the global variable "exception".
68 *
69 * Interrupts are disabled; they should be re-enabled when the exception is
70 * caught.
71 */
72
73void
74exraise(int e)
75{
76	INTOFF;
77	if (handler == NULL)
78		abort();
79	exception = e;
80	longjmp(handler->loc, 1);
81}
82
83
84/*
85 * Called from trap.c when a SIGINT is received and not suppressed, or when
86 * an interrupt is pending and interrupts are re-enabled using INTON.
87 * (If the user specifies that SIGINT is to be trapped or ignored using the
88 * trap builtin, then this routine is not called.)  Suppressint is nonzero
89 * when interrupts are held using the INTOFF macro.  If SIGINTs are not
90 * suppressed and the shell is not a root shell, then we want to be
91 * terminated if we get here, as if we were terminated directly by a SIGINT.
92 * Arrange for this here.
93 */
94
95void
96onint(void)
97{
98	sigset_t sigs;
99
100	intpending = 0;
101	sigemptyset(&sigs);
102	sigprocmask(SIG_SETMASK, &sigs, NULL);
103
104	/*
105	 * This doesn't seem to be needed, since main() emits a newline.
106	 */
107#if 0
108	if (tcgetpgrp(0) == getpid())
109		write(STDERR_FILENO, "\n", 1);
110#endif
111	if (rootshell && iflag)
112		exraise(EXINT);
113	else {
114		signal(SIGINT, SIG_DFL);
115		kill(getpid(), SIGINT);
116		_exit(128 + SIGINT);
117	}
118}
119
120
121static void
122vwarning(const char *msg, va_list ap)
123{
124	if (commandname)
125		outfmt(out2, "%s: ", commandname);
126	else if (arg0)
127		outfmt(out2, "%s: ", arg0);
128	doformat(out2, msg, ap);
129	out2fmt_flush("\n");
130}
131
132
133void
134warning(const char *msg, ...)
135{
136	va_list ap;
137	va_start(ap, msg);
138	vwarning(msg, ap);
139	va_end(ap);
140}
141
142
143/*
144 * Exverror is called to raise the error exception.  If the first argument
145 * is not NULL then error prints an error message using printf style
146 * formatting.  It then raises the error exception.
147 */
148static void
149verrorwithstatus(int status, const char *msg, va_list ap)
150{
151	/*
152	 * An interrupt trumps an error.  Certain places catch error
153	 * exceptions or transform them to a plain nonzero exit code
154	 * in child processes, and if an error exception can be handled,
155	 * an interrupt can be handled as well.
156	 *
157	 * exraise() will disable interrupts for the exception handler.
158	 */
159	FORCEINTON;
160
161#ifdef DEBUG
162	if (msg)
163		TRACE(("verrorwithstatus(%d, \"%s\") pid=%d\n",
164		    status, msg, getpid()));
165	else
166		TRACE(("verrorwithstatus(%d, NULL) pid=%d\n",
167		    status, getpid()));
168#endif
169	if (msg)
170		vwarning(msg, ap);
171	flushall();
172	exitstatus = status;
173	exraise(EXERROR);
174}
175
176
177void
178error(const char *msg, ...)
179{
180	va_list ap;
181	va_start(ap, msg);
182	verrorwithstatus(2, msg, ap);
183	va_end(ap);
184}
185
186
187void
188errorwithstatus(int status, const char *msg, ...)
189{
190	va_list ap;
191	va_start(ap, msg);
192	verrorwithstatus(status, msg, ap);
193	va_end(ap);
194}
195