Function exit ends program execution.
ANSI_SYNOPSIS
#include <stdlib.h> void exit(int code);
DESCRIPTION
Use exit to return control from a program to the host operating environment. Use the argument code to pass an exit status to the operating environment: two particular values,EXIT_SUCCESS and EXIT_FAILURE, are defined in <stdlib.h> to indicate success or failure in a portable fashion.
exit does two kinds of cleanup before ending execution of your program. First, it calls all application-defined cleanup functions you have enrolled with atexit. Second, files and streams are cleaned up: any pending output is delivered to the host system, each open file or stream is closed, and files created by tmpfile are deleted.
RETURNS
exit does not return to its caller.
Supporting OS subroutines required: _exit. (see source)
#include <stdlib.h>
#include <unistd.h> /* for _exit() declaration */
#include <reent.h>
#ifndef _REENT_ONLY
/*
* Exit, flushing stdio buffers if necessary.
*/
void
_DEFUN (exit, (code),
int code)
{
register struct _atexit *p;
register struct _on_exit_args * args;
register int n;
int i;
p = _GLOBAL_REENT->_atexit;
while (p)
{
args = & p->_on_exit_args;
for (n = p->_ind - 1, i = (n >= 0) ? (1 << n) : 0; n >= 0; --n, i >>= 1)
if (args->_fntypes & i)
(*((void (*)(int, void *)) p->_fns[n]))(code, args->_fnargs[n]);
else
p->_fns[n] ();
p = p->_next;
}
#ifndef WANT_SMALL_STDIO
if (_GLOBAL_REENT->__cleanup)
(*_GLOBAL_REENT->__cleanup) (_GLOBAL_REENT);
#endif
_exit (code);
}
#endif
000002d8 <exit>: 2d8: d0a00217 ldw r2,-32760(gp) 2dc: defff804 addi sp,sp,-32 2e0: dd800015 stw r22,0(sp) 2e4: dfc00715 stw ra,28(sp) 2e8: dc000615 stw r16,24(sp) 2ec: dc400515 stw r17,20(sp) 2f0: dc800415 stw r18,16(sp) 2f4: dcc00315 stw r19,12(sp) 2f8: dd000215 stw r20,8(sp) 2fc: dd400115 stw r21,4(sp) 300: 15005217 ldw r20,328(r2) 304: 202d883a mov r22,r4 308: a0002526 beq r20,zero,3a0 <exit+0xc8> 30c: a0800117 ldw r2,4(r20) 310: a5402204 addi r21,r20,136 314: 0027883a mov r19,zero 318: 143fffc4 addi r16,r2,-1 31c: 8006803a cmplt r3,r16,zero 320: 1800021e bne r3,zero,32c <exit+0x54> 324: 00800044 movi r2,1 328: 1426983a sll r19,r2,r16 32c: 1800191e bne r3,zero,394 <exit+0xbc> 330: 800490ba slli r2,r16,2 334: 1025883a mov r18,r2 338: 1505883a add r2,r2,r20 33c: 14400204 addi r17,r2,8 340: 00000806 br 364 <exit+0x8c> 344: 88800017 ldw r2,0(r17) 348: 29400017 ldw r5,0(r5) 34c: 843fffc4 addi r16,r16,-1 350: 94bfff04 addi r18,r18,-4 354: 103ee83a callr r2 358: 8c7fff04 addi r17,r17,-4 35c: 9827d07a srai r19,r19,1 360: 80000c16 blt r16,zero,394 <exit+0xbc> 364: a8802017 ldw r2,128(r21) 368: 954b883a add r5,r18,r21 36c: b009883a mov r4,r22 370: 14c4703a and r2,r2,r19 374: 103ff31e bne r2,zero,344 <exit+0x6c> 378: 88800017 ldw r2,0(r17) 37c: 843fffc4 addi r16,r16,-1 380: 94bfff04 addi r18,r18,-4 384: 103ee83a callr r2 388: 8c7fff04 addi r17,r17,-4 38c: 9827d07a srai r19,r19,1 390: 803ff40e bge r16,zero,364 <exit+0x8c> 394: a5000017 ldw r20,0(r20) 398: a03fdc1e bne r20,zero,30c <exit+0x34> 39c: d0a00217 ldw r2,-32760(gp) 3a0: 10c00f17 ldw r3,60(r2) 3a4: 1800021e bne r3,zero,3b0 <exit+0xd8> 3a8: b009883a mov r4,r22 3ac: 000045c0 call 45c <_exit> 3b0: 1009883a mov r4,r2 3b4: 183ee83a callr r3 3b8: 003ffb06 br 3a8 <exit+0xd0>
0x000002d8 <exit>: 0xd0a00217 ldw r2, -32760(gp) [memAddr=0x808 ldData=0x48c dstReg=r2] 0x000002dc <exit+0x4>: 0xdefff804 addi sp, sp, -32 [dstData=0x7fffedc dstReg=sp] 0x000002e0 <exit+0x8>: 0xdd800015 stw r22, 0(sp) [memAddr=0x7fffedc stData=0xdeadbeef] 0x000002e4 <exit+0xc>: 0xdfc00715 stw ra, 28(sp) [memAddr=0x7fffef8 stData=0x2cc] 0x000002e8 <exit+0x10>: 0xdc000615 stw r16, 24(sp) [memAddr=0x7fffef4 stData=0xdeadbeef] 0x000002ec <exit+0x14>: 0xdc400515 stw r17, 20(sp) [memAddr=0x7fffef0 stData=0xdeadbeef] 0x000002f0 <exit+0x18>: 0xdc800415 stw r18, 16(sp) [memAddr=0x7fffeec stData=0xdeadbeef] 0x000002f4 <exit+0x1c>: 0xdcc00315 stw r19, 12(sp) [memAddr=0x7fffee8 stData=0xdeadbeef] 0x000002f8 <exit+0x20>: 0xdd000215 stw r20, 8(sp) [memAddr=0x7fffee4 stData=0xdeadbeef] 0x000002fc <exit+0x24>: 0xdd400115 stw r21, 4(sp) [memAddr=0x7fffee0 stData=0xdeadbeef] 0x00000300 <exit+0x28>: 0x15005217 ldw r20, 328(r2) [memAddr=0x5d4 ldData=0x0 dstReg=r20] 0x00000304 <exit+0x2c>: 0x202d883a mov r22, r4 [dstData=0x0 dstReg=r22] 0x00000308 <exit+0x30>: 0xa0002526 beq r20, r0, 0x3a0 <exit+0xc8> [passed] 0x000003a0 <exit+0xc8>: 0x10c00f17 ldw r3, 60(r2) [memAddr=0x4c8 ldData=0x0 dstReg=r3] 0x000003a4 <exit+0xcc>: 0x1800021e bne r3, r0, 0x3b0 <exit+0xd8> [failed] 0x000003a8 <exit+0xd0>: 0xb009883a mov r4, r22 [dstData=0x0 dstReg=r4] 0x000003ac <exit+0xd4>: 0x000045c0 call 0x45c <_exit> [dstData=0x3b0 dstReg=ra]
extern void _do_dtors (void);
void __fake_fini () { /* Do nothing */ }
void _fini () __attribute__ ((weak, alias ("__fake_fini")));
void
_exit (int exit_code)
{
_fini ();
/* ??? May want a return to germs (or other) here? */
__asm__ (
"mov\tr2, %0\n"
"0:\n"
"\tbr\t0b"
:
: "r" (exit_code));
}
Note that _exit finishes with an instruction that branches to itself (address 0x474) and therefore never returns.
00000458 <__fake_fini>: 458: f800283a ret 0000045c <_exit>: 45c: defffe04 addi sp,sp,-8 460: dc400015 stw r17,0(sp) 464: dfc00115 stw ra,4(sp) 468: 2023883a mov r17,r4 46c: 00004580 call 458 <__fake_fini> 470: 8805883a mov r2,r17 474: 003fff06 br 474 <_exit+0x18> 478: dfc00117 ldw ra,4(sp) 47c: dc400017 ldw r17,0(sp) 480: dec00204 addi sp,sp,8 484: f800283a ret
0x0000045c <_exit>: 0xdefffe04 addi sp, sp, -8 [dstData=0x7fffed4 dstReg=sp] 0x00000460: 0xdc400015 stw r17, 0(sp) [memAddr=0x7fffed4 stData=0xdeadbeef] 0x00000464: 0xdfc00115 stw ra, 4(sp) [memAddr=0x7fffed8 stData=0x3b0] 0x00000468: 0x2023883a mov r17, r4 [dstData=0x0 dstReg=r17] 0x0000046c: 0x00004580 call 0x458 <__fake_fini> [dstData=0x470 dstReg=ra] 0x00000458 <__fake_fini>: 0xf800283a ret [targetPcb=0x470] 0x00000470: 0x8805883a mov r2, r17 [dstData=0x0 dstReg=r2] 0x00000474: 0x003fff06 br 0x474
Maintained by John Loomis, last updated 6 April 2007