freebsd-dev/bin/sh/error.h
Jilles Tjoelker 45496405c6 sh: Allow EV_EXIT through function calls, make {...} <redir more consistent.
If EV_EXIT causes an exit, use the exception mechanism to unwind
redirections and local variables. This way, if the final command is a
redirected command, an EXIT trap now executes without the redirections.

Because of these changes, EV_EXIT can now be inherited by the body of a
function, so do so. This means that a function no longer prevents a fork
before an exec being skipped, such as in
  f() { head -1 /etc/passwd; }; echo $(f)

Wrapping a single builtin in a function may still cause an otherwise
unnecessary fork with command substitution, however.

An exit command or -e failure still invokes the EXIT trap with the
original redirections and local variables in place.

Note: this depends on SHELLPROC being gone. A SHELLPROC depended on
keeping the redirections and local variables and only cleaning up the
state to restore them.
2011-04-23 22:28:56 +00:00

95 lines
3.6 KiB
C

/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)error.h 8.2 (Berkeley) 5/4/95
* $FreeBSD$
*/
/*
* We enclose jmp_buf in a structure so that we can declare pointers to
* jump locations. The global variable handler contains the location to
* jump to when an exception occurs, and the global variable exception
* contains a code identifying the exception. To implement nested
* exception handlers, the user should save the value of handler on entry
* to an inner scope, set handler to point to a jmploc structure for the
* inner scope, and restore handler on exit from the scope.
*/
#include <setjmp.h>
#include <signal.h>
struct jmploc {
jmp_buf loc;
};
extern struct jmploc *handler;
extern volatile sig_atomic_t exception;
/* exceptions */
#define EXINT 0 /* SIGINT received */
#define EXERROR 1 /* a generic error */
#define EXEXEC 2 /* command execution failed */
#define EXEXIT 3 /* call exitshell(exitstatus) */
/*
* These macros allow the user to suspend the handling of interrupt signals
* over a period of time. This is similar to SIGHOLD to or sigblock, but
* much more efficient and portable. (But hacking the kernel is so much
* more fun than worrying about efficiency and portability. :-))
*/
extern volatile sig_atomic_t suppressint;
extern volatile sig_atomic_t intpending;
#define INTOFF suppressint++
#define INTON { if (--suppressint == 0 && intpending) onint(); }
#define is_int_on() suppressint
#define SETINTON(s) suppressint = (s)
#define FORCEINTON {suppressint = 0; if (intpending) onint();}
#define CLEAR_PENDING_INT intpending = 0
#define int_pending() intpending
void exraise(int) __dead2;
void onint(void);
void warning(const char *, ...) __printflike(1, 2);
void error(const char *, ...) __printf0like(1, 2) __dead2;
void exerror(int, const char *, ...) __printf0like(2, 3) __dead2;
/*
* BSD setjmp saves the signal mask, which violates ANSI C and takes time,
* so we use _setjmp instead.
*/
#define setjmp(jmploc) _setjmp(jmploc)
#define longjmp(jmploc, val) _longjmp(jmploc, val)