Using source line numbers

OK, here's quick guide how you can quickly add support for the %L symbol that gives you the number of currently processed source line.

First, you need to modify the PARSER.INC file, so the parser will be able to recognize the %L symbol. Find the "get_predefined_id" label (somewhere around line 826), somewhere below it you can find those two lines:

Code:

        cmp     al,'t'
        je      get_timestamp_id

just after them you can add check for any additional "%+letter" symbols you want to use, in this case:

Code:

        cmp     al,'l'
        je      get_linenumber_id

The "get_timestamp_id" routine is defined somewhere above, you can add the "get_linenumber_id" just after it, and it should look like:

Code:

      get_linenumber_id:
        mov     eax,3
        ret

where 3 is the identifier of %L symbol which will appear in the parsed source.

Now you have to modify also EXPRESSI.INC file to allow the assembler to recognize this new type of symbol and get the right value for it during the calculations. Find the "predefined_label" routine (around line 999), it looks like:

Code:

      predefined_label:
        or      eax,eax
        jz      current_offset_label
        cmp     eax,1
        je      counter_label
        cmp     eax,2
        je      timestamp_label

of course you have to add there something like:

Code:

        cmp     eax,3
        je      linenumber_label

The "timestamp_label" routine is just above, after it you can add the routine that gets the number of current line:

Code:

      linenumber_label:
        mov     eax,[current_line]
        mov     eax,[eax+4]
        jmp     make_dword_label_value

And that's all - now you can use %L symbol to get the line number. Please note that in case of line inside the macro, it has the bit 31 set, and the lower bits contain the number of line in the macro, not in the file. To get number of source line that invoked the macro or number of line in macro definition, you would have to make some more modifications.