libc.obj: update exit (#340)

## New functions:
+ implement `_exit`/`_Exit`.
+ implement `atexit`.
+ implement `abort`.
`abort` write `Aborted pid: %d` to debug board

## Changes:

### call `exit` after main.
Just calling `exit`

### `exit` write exit code
If exit code isn't 0 `exit` will write exit code to debug board.

### use `con_exit(0)`
use
```c
con_exit(0)
```
instead of
```c
con_exit(status);
```
[from console.obj readme](310999dcc4/programs/develop/libraries/console_coff/console_en.txt (L15)).
I think the console window shouldn't be so dependent on the exit code. It's must only always close or always stay on screen

### `exit` writing exit code to debug board
Since the exit code is not used anywhere right now, I think it's better to just show it on the debug board.

for auto rebuild `crt0.o` need #339

from #311

---------

Co-authored-by: Burer <burer@kolibrios.org>
Reviewed-on: #340
Reviewed-by: Mikhail Frolov <mixa.frolov2003@gmail.com>
Reviewed-by: Burer <burer@kolibrios.org>
Co-authored-by: Egor00f <y.yarin@inbox.ru>
Co-committed-by: Egor00f <y.yarin@inbox.ru>

programs/develop/ktcc/bin/lib/libc.def

@@ -52,7 +52,10 @@ atol
 atoll
 atof
 calloc
+atexit
 exit
+_exit
+abort
 free
 itoa
 labs

programs/develop/ktcc/libc.obj/include/stdlib.h

@@ -48,8 +48,17 @@ DLLAPI void free(void* ptr);
 
 DLLAPI long int strtol(const char* str, char** endptr, int base);
 
+DLLAPI int atexit(void (*func)(void));
+
 DLLAPI void exit(int status);
 
+DLLAPI void _exit(int status);
+#ifndef _Exit
+#define _Exit(status) _exit(status)
+#endif
+
+DLLAPI void abort(void);
+
 DLLAPI void srand(unsigned s);
 DLLAPI int rand(void);
 

programs/develop/ktcc/libc.obj/samples/Makefile

@@ -27,7 +27,9 @@ BIN = \
 	libc_test.kex \
 	pipe.kex \
 	defgen.kex \
-	futex.kex
+	futex.kex \
+	atexit_test.kex \
+	abort_test.kex
 
 all: $(BIN)
 

programs/develop/ktcc/libc.obj/samples/abort_test.c

@@ -0,0 +1,7 @@
+#include <stdlib.h>
+
+int main()
+{
+    abort();
+    return 0;
+}

programs/develop/ktcc/libc.obj/samples/atexit_test.c

@@ -0,0 +1,18 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+void f()
+{
+    static int c = 1;
+    printf("exit #%d\n", c);
+    c++;
+}
+
+int main()
+{
+    atexit(&f);
+    atexit(&f);
+    atexit(&f);
+
+    return 0;
+}

programs/develop/ktcc/libc.obj/samples/build_all.sh

@@ -23,5 +23,7 @@ cp     clayer/logo.png /tmp0/1/tcc_samples/logo.png
 ../tcc defgen.c -o /tmp0/1/tcc_samples/defgen
 ../tcc pipe.c -o /tmp0/1/tcc_samples/pipe
 ../tcc futex.c -o /tmp0/1/tcc_samples/futex
+../tcc atexit_test.c -o /tmp0/1/tcc_samples/atexit_test
+../tcc abort_test.c -o /tmp0/1/tcc_samples/abort_test
 "/sys/File managers/Eolite" /tmp0/1/tcc_samples
 exit

programs/develop/ktcc/libc.obj/source/crt/crt0.asm

@@ -1,8 +1,6 @@
 ; SPDX-License-Identifier: NOASSERTION
 ;
 
-; Text encoded with Code Page 1251 - Cyrillic
-
 ;
 ;   2021, Edited by Coldy
 ;
@@ -19,6 +17,7 @@ public start
 public start as '_start'
 
 extrn main
+extrn exit
 
 include '../../../../../proc32.inc'
 include '../../../../../macros.inc'
@@ -43,36 +42,36 @@ start:
     call push_param
 ; retrieving parameters
     mov  esi, params
-    xor  edx, edx  ; dl - шф╕Є ярЁрьхЄЁ(1) шыш ЁрчфхышЄхыш(0)
-                   ; dh - ёшьтюы ё ъюЄюЁюую эрўрыё  ярЁрьхЄЁ (1 ърт√ўъш, 0 юёЄры№эюх)
+    xor  edx, edx  ; dl - is it a parameter (1) or delimiters (0)
+                   ; dh - character with which the parameter started (1 quotes, 0 everything else)
     mov  ecx, 1    ; cl = 1
-                   ; ch = 0  яЁюёЄю эюы№
+                   ; ch = 0  just zero
 .parse:
     lodsb
     test al, al
     jz   .run
     test dl, dl
     jnz  .findendparam
-                     ;{хёыш с√ы ЁрчфхышЄхы№
+                     ;{if it was a delimiter
     cmp  al, ' '
-    jz   .parse  ;чруЁєцхэ яЁюсхы, уЁєчшь ёыхфє■∙шщ ёшьтюы
-    mov  dl, cl  ;эрўшэрхЄё  ярЁрьхЄЁ
+    jz   .parse  ; space loaded, load next character
+    mov  dl, cl  ; parameter starts
     cmp  al, '"'
-    jz   @f      ;чруЁєцхэ√ ърт√ўъш
-    mov  dh, ch     ;ярЁрьхЄЁ схч ърт√ўхъ
+    jz   @f      ; quotes loaded
+    mov  dh, ch  ; parameter without quotes
     dec  esi
     call push_param
     inc  esi
     jmp  .parse
 
   @@:
-    mov  dh, cl     ;ярЁрьхЄЁ т ърт√ўхърї
-    call push_param ;хёыш эх яЁюсхы чэрўшЄ эрўшэрхЄё  ъръющ Єю ярЁрьхЄЁ
-    jmp  .parse     ;хёыш с√ы ЁрчфхышЄхы№}
+    mov  dh, cl     ; parameter in quotes
+    call push_param ; if not a space, then some parameter starts
+    jmp  .parse     ; if it was a delimiter}
 
 .findendparam:
     test dh, dh
-    jz   @f ; схч ърт√ўхъ
+    jz   @f ; without quotes
     cmp  al, '"'
     jz   .clear
     jmp  .parse
@@ -91,9 +90,8 @@ start:
     push [argc]
     call main
 .exit:
-    xor  eax,eax
-    dec  eax
-    int  0x40
+    push eax
+    call dword [exit]
     dd   -1
 .crash:
     jmp  .exit

programs/develop/ktcc/libc.obj/source/libc.c

@@ -90,6 +90,9 @@
 #include "stdlib/atoll.c"
 #include "stdlib/calloc.c"
 #include "stdlib/exit.c"
+#include "stdlib/_exit.c"
+#include "stdlib/atexit.c"
+#include "stdlib/abort.c"
 #include "stdlib/free.c"
 #include "stdlib/itoa.c"
 #include "stdlib/labs.c"
@@ -171,6 +174,9 @@ ksys_dll_t EXPORTS[] = {
     { "atof", &atof },
     { "calloc", &calloc },
     { "exit", &exit },
+    { "_exit", &_exit },
+    { "atexit", &atexit },
+    { "abort", &abort},
     { "free", &free },
     { "itoa", &itoa },
     { "labs", &labs },

programs/develop/ktcc/libc.obj/source/stdlib/_exit.c

@@ -0,0 +1,11 @@
+#include <conio.h>
+#include <sys/ksys.h>
+
+void _exit(int status)
+{
+    if (__con_is_load) {
+        con_exit(0);
+    }
+
+    _ksys_exit();
+}

programs/develop/ktcc/libc.obj/source/stdlib/abort.c

@@ -0,0 +1,17 @@
+/*
+* SPDX-License-Identifier: GPL-2.0-only
+* Copyright (C) 2026 KolibriOS team
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ksys.h>
+
+void abort(void)
+{
+    ksys_thread_t t;
+    _ksys_thread_info(&t, -1);
+    fprintf(stderr, "\nAborted pid: %d\n", t.pid);
+
+    _exit(128);
+}

programs/develop/ktcc/libc.obj/source/stdlib/atexit.c

@@ -0,0 +1,40 @@
+/*
+* SPDX-License-Identifier: GPL-2.0-only
+* Copyright (C) 2026 KolibriOS team
+*/
+
+#include <stdlib.h>
+
+struct atexit_n {
+    struct atexit_n* last;
+    void (*func)(void);
+};
+
+static struct atexit_n* __last_atexit_node = NULL;
+
+int atexit(void (*func)(void))
+{
+    struct atexit_n* n = malloc(sizeof(struct atexit_n));
+
+    if (n == NULL) {
+        return 1;
+    }
+
+    n->last = __last_atexit_node;
+    n->func = func;
+
+    __last_atexit_node = n;
+
+    return 0;
+}
+
+void __run_atexit()
+{
+    struct atexit_n* n = __last_atexit_node;
+    while (n != NULL) {
+        n->func();
+        struct atexit_n* to_free = n;
+        n = n->last;
+        free(to_free);
+    }
+}

programs/develop/ktcc/libc.obj/source/stdlib/atexit.h

@@ -0,0 +1,6 @@
+#ifndef STDLIB_ATEXIT_H
+#define STDLIB_ATEXIT_H
+
+void __run_atexit();
+
+#endif

programs/develop/ktcc/libc.obj/source/stdlib/exit.c

@@ -1,12 +1,31 @@
 /* Copyright (C) 2021 Logaev Maxim (turbocat2001), GPLv2 */
 
-#include <conio.h>
-#include <sys/ksys.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "atexit.h"
+
+/*
+TODO
+static void __close_all()
+{
+}
+
+static void __free_all_mem()
+{
+}
+*/
 
 void exit(int status)
 {
-    if (__con_is_load) {
-        con_exit(status);
+    __run_atexit();
+
+    if(status)
+    {
+        fprintf(stderr, "Exit code: %d\n", status);
     }
-    _ksys_exit();
+
+    //__close_all();
+    //__free_all_mem();
+
+    _exit(status);
 }