absasm21.bas

如何在QBasic环境下实现和利用汇编

    PRINT #2, midline$
    PRINT #2, newline$
    errorcounter% = errorcounter% + 1
    linecounter% = linecounter% - 1
   END IF
   linecounter% = linecounter% + 1
LOOP UNTIL newline$ = "-u 100, 100"

CLOSE #2
CLOSE #1

IF errorcounter% > 0 THEN
 KILL tempfile1$
 KILL tempfile2$
 KILL tempfile3$
 PRINT
 PRINT "Error(s) in source code detected. Look in "; errorfile$; " for information."
 END
END IF

asmlength$ = MID$(oldline$, INSTR(oldline$, ":") + 1, 4)

PRINT "Source code byte length detected."

OPEN tempfile3$ FOR INPUT AS #1
OPEN tempfile4$ FOR OUTPUT AS #2

SEEK #1, SEEK(1) + 5

PRINT #2, "a"

DO
   LINE INPUT #1, sourceline$
   SEEK #1, SEEK(1) + 2
   sourceline$ = RIGHT$(sourceline$, LEN(sourceline$) - 10)
   IF LEN(sourceline$) > 0 THEN PRINT #2, sourceline$
LOOP UNTIL sourceline$ = ""

CLOSE #1

PRINT #2, ""
PRINT #2, "u 100, "; asmlength$
PRINT #2, "q"

CLOSE #2

' -------------------------------------------------------------------------- '
' Run DEBUG again to create a full output file:                              '
' -------------------------------------------------------------------------- '

SHELL rundebug$ + "<" + tempfile4$ + ">" + tempfile3$

' -------------------------------------------------------------------------- '
' Scan through DEBUG output file to get the byte offsets for the lines with  '
' labels in the sourcefile:                                                  '
' -------------------------------------------------------------------------- '

OPEN tempfile3$ FOR INPUT AS #1

DO
   LINE INPUT #1, readline$
LOOP UNTIL INSTR(readline$, "-u 100,")

SEEK #1, SEEK(1) + 2

labelcounter% = 1
linecounter% = 1

DO
   LINE INPUT #1, readline$
   IF label(labelcounter%).labelnum = linecounter% THEN
    label(labelcounter%).labelpos = MID$(readline$, 6, 4)
    labelcounter% = labelcounter% + 1
   END IF
   linecounter% = linecounter% + 1
LOOP UNTIL readline$ = "-q"
  
CLOSE #1

' -------------------------------------------------------------------------- '
' Update tempfile with the correct byte offset numbers for lines with labels '
' in the sourcefile:                                                         '
' -------------------------------------------------------------------------- '

OPEN tempfile2$ FOR INPUT AS #1
OPEN tempfile3$ FOR OUTPUT AS #2

PRINT #2, "a"

DO
   LINE INPUT #1, sourceline$
   FOR labelscan% = 1 TO numlabels%
      IF INSTR(sourceline$, LTRIM$(RTRIM$(label(labelscan%).labelname))) THEN
       sourceline$ = LEFT$(sourceline$, INSTR(sourceline$, LTRIM$(RTRIM$(label(labelscan%).labelname))) - 1) + label(labelscan%).labelpos
      END IF
   NEXT labelscan%
   PRINT #2, sourceline$
LOOP UNTIL EOF(1)

CLOSE #1

PRINT #2, ""
PRINT #2, "u 100, "; asmlength$
PRINT #2, "q"

CLOSE #2

PRINT "Label conversion completed."

' -------------------------------------------------------------------------- '
' Make a final pass through DEBUG to create final output file:               '
' -------------------------------------------------------------------------- '

SHELL rundebug$ + "<" + tempfile3$ + ">" + tempfile3$

PRINT "DEBUG output file successfully created."

' -------------------------------------------------------------------------- '
' Calculate the longest possible BASIC string declaration line:              '
' -------------------------------------------------------------------------- '

linecounter% = 1
longestline% = 0
maxsourcelength% = 0
maxcodelength% = 0

OPEN tempfile3$ FOR INPUT AS #1

DO
   LINE INPUT #1, readline$
LOOP UNTIL INSTR(readline$, "-u 100,")

SEEK #1, SEEK(1) + 2

DO
   LINE INPUT #1, readline$

   linelength% = LEN(RTRIM$(MID$(readline$, 11, 14)))

   IF linelength% >= longestline% THEN
    codelength% = 0
    FOR findcodelength% = 1 TO linelength% STEP 2
       IF MID$(RTRIM$(MID$(readline$, 11, 14)), findcodelength%, 1) = "0" THEN
	codelength% = codelength% + 1
       ELSE
	codelength% = codelength% + 2
       END IF
    NEXT findcodelength%
    IF maxsourcelength% < codelength% THEN maxsourcelength% = codelength%
    longestline% = linelength%
   END IF

   linecounter% = linecounter + 1
LOOP UNTIL readline$ = "-q"

maxcodelength% = LEN(codestring$) + 3 + LEN(codestring$) + (longestline% \ 2) * 11 + maxsourcelength%

CLOSE #1

' -------------------------------------------------------------------------- '
' Transform the source code to BASIC string declaration lines:               '
' -------------------------------------------------------------------------- '

FOR modifylabels% = 1 TO numlabels%
   MID$(label(modifylabels%).labelname, 2, 16) = LCASE$(RIGHT$(label(modifylabels%).labelname, 15))
NEXT modifylabels%

OPEN tempfile3$ FOR INPUT AS #1
OPEN tempfile1$ FOR INPUT AS #2

IF writemethod% = 1 THEN
 OPEN destfilename$ FOR APPEND AS #3
ELSE
 OPEN destfilename$ FOR OUTPUT AS #3
END IF

DO
   LINE INPUT #1, readline$
LOOP UNTIL INSTR(readline$, "-u 100,")

SEEK #1, SEEK(1) + 2

PRINT #3, "' ------ Created with Absolute Assembly 2.1 by Petter Holmberg, -97. ------- '"
PRINT #3, ""

PRINT #3, codestring$ + " = " + CHR$(34) + CHR$(34)

linecounter% = 1
labelcounter% = 1

DO
   LINE INPUT #1, readline$
   readline$ = RTRIM$(readline$)
   IF NOT EOF(2) THEN LINE INPUT #2, sourceline$ ELSE sourceline$ = ""

   IF readline$ <> "-q" THEN

    sourcedata$ = RTRIM$(MID$(readline$, 11, 14))
    basicline$ = codestring$ + " = " + codestring$

    FOR makebasicline% = 1 TO LEN(sourcedata$) STEP 2
       IF MID$(RTRIM$(MID$(readline$, 11, 14)), makebasicline%, 1) = "0" THEN
	basicline$ = basicline$ + " + CHR$(&H" + MID$(sourcedata$, makebasicline% + 1, 1) + ")"
       ELSE
	basicline$ = basicline$ + " + CHR$(&H" + MID$(sourcedata$, makebasicline%, 2) + ")"
       END IF
    NEXT makebasicline%

    IF LEN(basicline$) < maxcodelength% THEN basicline$ = basicline$ + SPACE$(maxcodelength% - LEN(basicline$))

    basicline$ = basicline$ + " ' "

    IF label(labelcounter%).labelnum = linecounter% THEN
     basicline$ = basicline$ + RTRIM$(label(labelcounter%).labelname) + ": "
     labelcounter% = labelcounter% + 1
    END IF

    asmline$ = (RIGHT$(readline$, (LEN(readline$) - 24)))
    IF INSTR(asmline$, CHR$(9)) THEN MID$(asmline$, INSTR(asmline$, CHR$(9))) = " "
    asmline$ = RTRIM$(asmline$)
    basicline$ = basicline$ + asmline$

    FOR labelscan% = 1 TO numlabels%
       IF INSTR(sourceline$, UCASE$(RTRIM$(label(labelscan%).labelname))) AND INSTR(sourceline$, ":") = 0 THEN
	basicline$ = LEFT$(basicline$, LEN(basicline$) - 4)
	basicline$ = basicline$ + RTRIM$(label(labelscan%).labelname)
       END IF
    NEXT labelscan%

    PRINT #3, basicline$

   END IF
  
   linecounter% = linecounter% + 1
LOOP UNTIL readline$ = "-q"

IF callabs% = 1 THEN
 PRINT #3, ""
 PRINT #3, "offset% = SADD("; codestring$; ")"
 PRINT #3, "DEF SEG = VARSEG("; codestring$; ")"
 PRINT #3, "CALL ABSOLUTE(offset%)"
 PRINT #3, "DEF SEG"
END IF

PRINT #3, ""
PRINT #3, "' ------ Created with Absolute Assembly 2.1 by Petter Holmberg, -97. ------- '"

CLOSE #3
CLOSE #2
CLOSE #1

PRINT "Source code successfully moved to BASIC destination file."

KILL tempfile1$
KILL tempfile2$
KILL tempfile3$
KILL tempfile4$

PRINT
PRINT "Time of conversion:"; TIMER - conversiontime!; "seconds."
PRINT

PRINT "Convert another file? (y/n)    : ";

DO
   kbd$ = INKEY$
   IF LCASE$(kbd$) = "n" THEN
    PRINT LCASE$(kbd$)
    END
   END IF
   IF LCASE$(kbd$) = "y" THEN
    PRINT LCASE$(kbd$)
    GOTO Start
   END IF
LOOP

END

' -------------------------------------------------------------------------- '
' Error handler:                                                             '
' -------------------------------------------------------------------------- '

ErrorHandler:

CLEAR
PRINT

PRINT "Whoops! An error occured during program execution."
PRINT "Check the spelling of your filenames and check the sourcefile for illegal lines."
PRINT
PRINT "Press any key to end program..."
DO: LOOP WHILE INKEY$ = ""
END