61 lines
2 KiB
C
61 lines
2 KiB
C
|
/* -*-comment-start: "//";comment-end:""-*-
|
||
|
|
* GNU Mes --- Maxwell Equations of Software
|
||
|
|
* Copyright © 2017,2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
|
||
|
|
* Copyright © 2020 Danny Milosavljevic <dannym@scratchpost.org>
|
||
|
|
*
|
||
|
|
* This file is part of GNU Mes.
|
||
|
|
*
|
||
|
|
* GNU Mes is free software; you can redistribute it and/or modify it
|
||
|
|
* under the terms of the GNU General Public License as published by
|
||
|
|
* the Free Software Foundation; either version 3 of the License, or (at
|
||
|
|
* your option) any later version.
|
||
|
|
*
|
||
|
|
* GNU Mes is distributed in the hope that it will be useful, but
|
||
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
* GNU General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <setjmp.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
|
||
|
|
void
|
||
|
|
longjmp (jmp_buf env, int val)
|
||
|
|
{
|
||
|
|
val = val == 0 ? 1 : val;
|
||
|
|
asm ("!0xc ldr____%r0,(%fp,+#$i8)"); // val
|
||
|
|
asm ("!0x8 ldr____%fp,(%fp,+#$i8)"); // env
|
||
|
|
|
||
|
|
asm ("!0x8 ldr____%sp,(%fp,+#$i8)"); // env.__sp
|
||
|
|
/* setjmp's ENV argument is missing in setjmp caller's frame. Re-add it. */
|
||
|
|
asm ("pop____%lr"); // junk
|
||
|
|
asm ("push___%ebp");
|
||
|
|
asm ("!0x4 ldr____%lr,(%fp,+#$i8)"); // env.__lr
|
||
|
|
|
||
|
|
asm ("!0x0 ldr____%fp,(%fp,+#$i8)"); // env.__fp
|
||
|
|
|
||
|
|
asm ("push___%lr");
|
||
|
|
/* Avoid function epilogue */
|
||
|
|
asm ("ret");
|
||
|
|
}
|
||
|
|
|
||
|
|
int
|
||
|
|
setjmp (__jmp_buf * env)
|
||
|
|
{
|
||
|
|
/* Function prelude emitter emits: push %lr; push %fp; %fp := %sp */
|
||
|
|
|
||
|
|
long *p = (long*)&env; // location of parameter on stack
|
||
|
|
env[0].__fp = p[-2]; // frame of caller of setjmp
|
||
|
|
env[0].__lr = p[-1]; // caller of setjmp
|
||
|
|
env[0].__sp = p; // stack of caller of setjmp (location of ENV value)
|
||
|
|
|
||
|
|
/* Function epilogue emitter emits: %sp := %fp; pop %fp; pop %lr; %pc := %lr.
|
||
|
|
That means that all of the setjmp state is gone after we return from setjmp.
|
||
|
|
Once we enter longjmp, we can't use setjmp state and have to reconstruct
|
||
|
|
the state of setjmp's call site instead. */
|
||
|
|
return 0;
|
||
|
|
}
|