xref: /freebsd/bin/sh/error.c (revision 97759ccc715c4b365432c16d763c50eecfcb1100)
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 #endif /* not lint */
35 #include <sys/cdefs.h>
36 /*
37  * Errors and exceptions.
38  */
39 
40 #include "shell.h"
41 #include "eval.h"
42 #include "main.h"
43 #include "options.h"
44 #include "output.h"
45 #include "error.h"
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 verrorwithstatus(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 re-enabled 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 and not suppressed, or when
89  * an interrupt is pending and interrupts are re-enabled using INTON.
90  * (If the user specifies that SIGINT is to be trapped or ignored using the
91  * trap builtin, then this routine is not called.)  Suppressint is nonzero
92  * when interrupts are held using the INTOFF macro.  If SIGINTs are not
93  * suppressed and the shell is not a root shell, then we want to be
94  * terminated if we get here, as if we were terminated directly by a SIGINT.
95  * Arrange for this here.
96  */
97 
98 void
99 onint(void)
100 {
101 	sigset_t sigs;
102 
103 	intpending = 0;
104 	sigemptyset(&sigs);
105 	sigprocmask(SIG_SETMASK, &sigs, NULL);
106 
107 	/*
108 	 * This doesn't seem to be needed, since main() emits a newline.
109 	 */
110 #if 0
111 	if (tcgetpgrp(0) == getpid())
112 		write(STDERR_FILENO, "\n", 1);
113 #endif
114 	if (rootshell && iflag)
115 		exraise(EXINT);
116 	else {
117 		signal(SIGINT, SIG_DFL);
118 		kill(getpid(), SIGINT);
119 		_exit(128 + SIGINT);
120 	}
121 }
122 
123 
124 static void
125 vwarning(const char *msg, va_list ap)
126 {
127 	if (commandname)
128 		outfmt(out2, "%s: ", commandname);
129 	else if (arg0)
130 		outfmt(out2, "%s: ", arg0);
131 	doformat(out2, msg, ap);
132 	out2fmt_flush("\n");
133 }
134 
135 
136 void
137 warning(const char *msg, ...)
138 {
139 	va_list ap;
140 	va_start(ap, msg);
141 	vwarning(msg, ap);
142 	va_end(ap);
143 }
144 
145 
146 /*
147  * Exverror is called to raise the error exception.  If the first argument
148  * is not NULL then error prints an error message using printf style
149  * formatting.  It then raises the error exception.
150  */
151 static void
152 verrorwithstatus(int status, const char *msg, va_list ap)
153 {
154 	/*
155 	 * An interrupt trumps an error.  Certain places catch error
156 	 * exceptions or transform them to a plain nonzero exit code
157 	 * in child processes, and if an error exception can be handled,
158 	 * an interrupt can be handled as well.
159 	 *
160 	 * exraise() will disable interrupts for the exception handler.
161 	 */
162 	FORCEINTON;
163 
164 #ifdef DEBUG
165 	if (msg)
166 		TRACE(("verrorwithstatus(%d, \"%s\") pid=%d\n",
167 		    status, msg, getpid()));
168 	else
169 		TRACE(("verrorwithstatus(%d, NULL) pid=%d\n",
170 		    status, getpid()));
171 #endif
172 	if (msg)
173 		vwarning(msg, ap);
174 	flushall();
175 	exitstatus = status;
176 	exraise(EXERROR);
177 }
178 
179 
180 void
181 error(const char *msg, ...)
182 {
183 	va_list ap;
184 	va_start(ap, msg);
185 	verrorwithstatus(2, msg, ap);
186 	va_end(ap);
187 }
188 
189 
190 void
191 errorwithstatus(int status, const char *msg, ...)
192 {
193 	va_list ap;
194 	va_start(ap, msg);
195 	verrorwithstatus(status, msg, ap);
196 	va_end(ap);
197 }
198