extra characters on line (missing "or al,al/jz"?)

Index > Compiler Internals > extra characters on line (missing "or al,al/jz"?)

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ouadji

Joined: 24 Dec 2008
Posts: 1081
Location: Belgium

ouadji 15 Aug 2011, 08:26

I'm not sure, but I think so.

Tomasz ?

Code:

;PREPROCE.INC
;------------
         .....
backslash_character:
           mov     byte[edi],0
         lods    byte[esi]
           cmp     al,20h
              je      concatenate_lines
           cmp     al,09h
              je      concatenate_lines
           cmp     al,1Ah
              je      unexpected_end_of_file
              cmp     al,0Ah
              je      concatenate_lf
              cmp     al,0Dh
              je      concatenate_cr
              or      al,al                   ;<-- +
           jz      concatenate_ok          ;<-- +
           cmp     al,3Bh
              je      find_concatenated_line

          .....

concatenate_lines:
         lods    byte[esi]
           cmp     al,20h
              je      concatenate_lines
           cmp     al,09h
              je      concatenate_lines
           cmp     al,1Ah
              je      unexpected_end_of_file
              cmp     al,0Ah
              je      concatenate_lf
              cmp     al,0Dh
              je      concatenate_cr
              or      al,al                   ;<-- +
           jz      concatenate_ok          ;<-- +
           cmp     al,3Bh
              jne     extra_characters_on_line
            .....

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Last edited by ouadji on 23 Aug 2011, 14:47; edited 1 time in total

15 Aug 2011, 08:26

ouadji

Joined: 24 Dec 2008
Posts: 1081
Location: Belgium

ouadji 20 Aug 2011, 20:01

Tomasz, your opinion on this ?
thank you in advance.

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20 Aug 2011, 20:01

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 20 Aug 2011, 20:02

Maybe you should explain what your patch does?

20 Aug 2011, 20:02

ouadji

Joined: 24 Dec 2008
Posts: 1081
Location: Belgium

ouadji 20 Aug 2011, 20:29

Code:

;PREPROCE.INC
;------------

control_character:
 cmp     al,1Ah
      je      line_end
    cmp     al,0Dh
      je      cr_character
        cmp     al,0Ah
      je      lf_character
        cmp     al,9
        je      convert_line_data
   or      al,al ;<---------------- al == 0 ?
       jnz     symbol_character
    jmp     line_end ;<------------- if al==0 then "end of line"
   ...

if zero means the end of line (like 0x0D and/or 0x0A)

then zero must mean the end of line in all cases.

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20 Aug 2011, 20:29

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 20 Aug 2011, 20:44

thanks. stickied.

20 Aug 2011, 20:44

ouadji

Joined: 24 Dec 2008
Posts: 1081
Location: Belgium

ouadji 23 Aug 2011, 14:43

The fasm compiler assumes that "zéro" means the end of line.
(like 0x0D and/or 0x0A)

Code:

;PREPROCE.INC
;------------

control_character:
        cmp     al,1Ah
        je      line_end
        cmp     al,0Dh
        je      cr_character
        cmp     al,0Ah
        je      lf_character
        cmp     al,9
        je      convert_line_data
        or      al,al ;<---------------- al == 0 ?
        jnz     symbol_character
        jmp     line_end ;<------------- if al==0 then "end of line"
        ...

However, after a backslash, it does not work.
The compiler does not take into accont the "zero" as end of line in all cases.
Here is a simple example (attached file).

Code:

db \ ;<--- eol==0
 1

Try to compile this file,
the result is: "extra characters on line"
why ?
Because the compiler sometimes sees the "zero" as the end of the line,
and sometimes as the end of the file.

(The solution is in my first post)

Description:		Download
Filename:	EOL_zero.ASM
Filesize:	7 Bytes
Downloaded:	489 Time(s)

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23 Aug 2011, 14:43

AsmGuru62

Joined: 28 Jan 2004
Posts: 1708
Location: Toronto, Canada

AsmGuru62 23 Aug 2011, 16:35

The backslash is a LAST character on line by its definition - and FASM 'knows' it perfectly well. Not a bug IMO.

23 Aug 2011, 16:35

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8394
Location: Kraków, Poland

Tomasz Grysztar 23 Aug 2011, 18:21

It should in fact treat 0 byte as EOF, but it's been broken because I did not add appropriate check in the parent loop when once (long time ago) restructuring the code. So it started working as EOL only, and that's why there is this inconsistency.

23 Aug 2011, 18:21

ouadji

Joined: 24 Dec 2008
Posts: 1081
Location: Belgium

ouadji 23 Aug 2011, 18:47

thank you Tomasz for your reply.

Ok, understood.
Maybe it's time to fix this small inconsistency.
Why not ?

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23 Aug 2011, 18:47

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