source: mainline/uspace/lib/c/generic/setjmp.c@ 9696b01

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 9696b01 was 91e22dc, checked in by Vojtech Horky <vojtechhorky@…>, 12 years ago

setjmp() shall be a macro according to C standard

As a matter of fact, when it is a function, the context that was
saved may no longer exist. Excerpt from IRC follows:

vhotspur: jermar, hi: what makes you think setjmp needs to be macro
vhotspur: hmmmm, C99 states that setjmp is macro and longjmp is function,

POSIX states that setjmp can be either macro or function

jermar: from what we have learned about context_save over the years
jermar: you basically capture the stack pointer in context_save()
jermar: if it is a function, you immediately deallocate part of that stack
jermar: so later to return to something which has once been a stack,

but is not anymore

jermar: for instance, you could expect to find the return address from

the call to setjmp() on it, but that could have been overwritten
by some further use of the stack

Also fixed bad definition of buffer type.

  • Property mode set to 100644
File size: 2.1 KB
Line 
1/*
2 * Copyright (c) 2013 Vojtech Horky
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup libc
30 * @{
31 */
32/** @file Long jump implementation.
33 *
34 * Implementation inspired by Jiri Zarevucky's code from
35 * http://bazaar.launchpad.net/~zarevucky-jiri/helenos/stdc/revision/1544/uspace/lib/posix/setjmp.h
36 */
37
38#include <setjmp.h>
39#include <libarch/fibril.h>
40#include <fibril.h>
41
42/**
43 * Restore environment previously stored by setjmp.
44 *
45 * This function never returns.
46 *
47 * @param env Variable with the environment previously stored by call
48 * to setjmp.
49 * @param val Value to fake when returning from setjmp (0 is transformed to 1).
50 */
51void longjmp(jmp_buf env, int val) {
52 env[0].return_value = (val == 0) ? 1 : val;
53 context_restore(&env[0].context);
54 __builtin_unreachable();
55}
56
57/** @}
58 */
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