Local labels in TASM: Symbol already defined

问题

I want to use local labels in my procedures to prevent the use of prefixes for common labels in my program. I tried using local labels (@@). According to my book, "The life of a local label extends only forward and back to the next nonlocal label". However, when I try to compile the file, the following error message is returned:

Turbo Assembler  Version 3.1  Copyright (c) 1988, 1992 Borland International

Assembling file:   test.ASM
**Error** test.ASM(20) Symbol already defined elsewhere: @@EXIT
**Error** test.ASM(33) Symbol already defined elsewhere: @@EXIT
Error messages:    2   
Warning messages:  None
Passes:            1   
Remaining memory:  472k

Here is the source code:

Data    segment
Data    ends

Stack1  segment Stack "Stack"
    dw  256 dup(?)
Stack1  ends

Code    segment
assume cs:Code, ss:Stack1, ds:Data
.386

proc1   proc
    ; some code here
    @@exit:
    ret
proc1   endp

proc2   proc
    ; some code here
    @@exit:
    ret
proc2   endp

main    proc
    mov ax, Data
    mov ds, ax

    @@repeat:
    call    proc1
    call    proc2
    jz  @@repeat

    @@exit:
    mov ah, 4Ch
    mov al, 0
    int 21h     
main    endp

Code    ends

end main

回答1:

Local symbols isn't enabled by default. To enable it, the LOCALS directive is needed in the source. This directive must be placed in its own line and can be used multiple times. It needs one parameter that consist of two characters. This text will be used as the prefix for all local symbols.

For example: LOCALS @@ or LOCALS ZZ

来源：https://stackoverflow.com/questions/13221789/local-labels-in-tasm-symbol-already-defined