xref: /freebsd/bin/sh/error.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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 
56 struct jmploc *handler;
57 volatile sig_atomic_t exception;
58 volatile sig_atomic_t suppressint;
59 volatile sig_atomic_t intpending;
60 
61 
62 static 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 
73 void
74 exraise(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 
95 void
96 onint(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 
121 static void
122 vwarning(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 
133 void
134 warning(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  */
148 static void
149 verrorwithstatus(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 
177 void
178 error(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 
187 void
188 errorwithstatus(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