v4.0/src/CMD/REPLACE/_REPLACE.ASM

   1 page    60,132                          ;\ f
   2 name    _replace
   3 title   Critical error or control break exit
   4 ;-------------------------------------------------------------------
   5 ;
   6 ;       MODULE:         _replace
   7 ;
   8 ;       PURPOSE:        Supplies assembler exit routines for
   9 ;                       critical error or control break situations
  10 ;
  11 ;       CALLING FORMAT:
  12 ;                       crit_err_handler;
  13 ;                       ctl_brk_handler;
  14 ;
  15 ;       DATE:           10/87
  16 ;
  17 ;-------------------------------------------------------------------
  18
  19
  20         public  _crit_err_handler       ;AN000;
  21         public  _ctl_brk_handler        ;AN000;
  22
  23 ;-------------------------------------------------------------------
  24 RET_EXIT equ    4ch                     ; terminate                             ;AN000;
  25 CTLBRK  equ     3                       ; errorlevel return in al               ;AN000;
  26 ABORT   equ     2                       ; if >=, retry                          ;AN000;
  27 XABORT  equ     1                       ; errorlevel return in al               ;AN000;
  28 ;-------------------------------------------------------------------
  29
  30
  31 NULL    SEGMENT PARA PUBLIC 'BEGDATA'   ;AN000;
  32 NULL    ENDS                            ;AN000;
  33 _DATA   SEGMENT PARA PUBLIC 'DATA'      ;AN000;
  34         extrn   _oldint24:dword         ;AN000;
  35 _DATA   ENDS                            ;AN000;
  36 CONST   SEGMENT WORD PUBLIC 'CONST'     ;AN000;
  37 CONST   ENDS                            ;AN000;
  38 _BSS    SEGMENT WORD PUBLIC 'BSS'       ;AN000;
  39 _BSS    ENDS                            ;AN000;
  40 STACK   SEGMENT PARA STACK 'DATA'       ;AN000;
  41 STACK   ENDS                            ;AN000;
  42
  43 PGROUP  GROUP   _TEXT                   ;AN000;
  44 DGROUP  GROUP   NULL, _DATA, CONST, _BSS, STACK ;AN000;
  45
  46
  47
  48 _TEXT   segment para public 'CODE'      ;AN000;
  49         ASSUME  CS:PGROUP               ;AN000;
  50
  51         extrn   _restore:near           ;AN000;
  52
  53 ;-------------------------------------------------------------------
  54 ; CRITICAL ERROR HANDLER
  55 ;-------------------------------------------------------------------
  56 vector  dd      0                       ;receives a copy of _oldint24           ;AN000;
  57
  58 _crit_err_handler proc near             ;AN000;
  59
  60         pushf                           ; req by int24 handler                  ;AN000;
  61         push    ax                      ; will use ax                           ;AN000;
  62         push    ds                      ; will use ds                           ;AN000;
  63
  64         mov     ax,dgroup               ; setup                                 ;AN000;
  65         mov     ds,ax                   ;                                       ;AN000;
  66         ASSUME  DS:DGROUP               ;AN000;
  67
  68         mov     ax,word ptr _oldint24   ; load vector so we can use it          ;AN000;
  69         mov     word ptr vector,ax      ;                                       ;AN000;
  70         mov     ax,word ptr _oldint24+2 ;                                       ;AN000;
  71         mov     word ptr vector+2,ax    ;                                       ;AN000;
  72
  73         pop     ds                      ; finished with ds                      ;AN000;
  74         ASSUME  DS:NOTHING
  75
  76         pop     ax                      ; finished with ax                      ;AN000;
  77
  78         call    dword ptr vector        ; invoke DOS err hndlr                  ;AN000;
  79
  80         cmp     al,ABORT                ; what was the user's response          ;AN000;
  81         jnge    retry                   ;                                       ;AN000;
  82
  83         mov     ax,(RET_EXIT shl 8)+XABORT ; return to DOS w/criterr error      ;AN000;
  84         call    call_restore            ; restore user's orig append/x          ;AN000;
  85 ; =================== this call does not return ===============
  86
  87 retry:                                  ;AN000;
  88         ASSUME  DS:NOTHING
  89         ASSUME  ES:NOTHING
  90
  91         iret                            ; user response was "retry"             ;AN000;
  92
  93 _crit_err_handler endp                  ;AN000;
  94
  95
  96 ;-------------------------------------------------------------------
  97 ; CONTROL BREAK HANDLER
  98 ;-------------------------------------------------------------------
  99 _ctl_brk_handler proc near              ;AN000;
 100
 101         ASSUME  DS:NOTHING
 102         ASSUME  ES:NOTHING
 103
 104         mov     ax,(RET_EXIT shl 8)+CTLBRK ; return to DOS w/ctlbrk error       ;AN000;
 105 ;-------------------------------------------------------------------
 106         call    call_restore            ; restore user's orig append/x          ;AN000;
 107 ;-------------------------------------------------------------------
 108 ; =================== this call does not return ===============
 109
 110 _ctl_brk_handler endp                   ;AN000;
 111
 112 call_restore proc near
 113 ;input: ah has the RETURN TO DOS WITH RET CODE function request
 114 ;       al has the ERRORLEVEL return code to be passed back to DOS
 115 ;output: this routine does NOT RETURN, but exits to DOS with ret code.
 116
 117         push    ax                      ;save errorlevel return code
 118         push    ds
 119         push    es
 120
 121         mov     ax,dgroup               ; setup "c" code regs                   ;AN000;
 122         mov     ds,ax                   ;                                       ;AN000;
 123         ASSUME  DS:DGROUP               ;AN000;
 124
 125         mov     es,ax                   ;                                       ;AN000;
 126         ASSUME  ES:DGROUP               ;AN000;
 127
 128 ;-------------------------------------------------------------------
 129         call    _restore                ; restore user's orig append/x          ;AN000;
 130 ;-------------------------------------------------------------------
 131
 132         pop     es
 133         pop     ds
 134         pop     ax                      ;restore return code
 135         int     21h                     ;                                       ;AN000;
 136         int     20h                     ; in case int21 fails                   ;AN000;
 137
 138 call_restore endp
 139
 140 _TEXT   ends                            ; end code segment                      ;AN000;
 141         end                             ;AN000;
 142 \1a