New mainargs module from Stefan Haubenthal

git-svn-id: svn://svn.cc65.org/cc65/trunk@2804 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/apple2/mainargs.s b/libsrc/apple2/mainargs.s
index ebe6d03481e892b017eb3fec7811f5bb7fc429a5..f4481214924b2b78a44779db5294b3e561f81568 100644 (file)
--- a/libsrc/apple2/mainargs.s
+++ b/libsrc/apple2/mainargs.s
@@ -1,21 +1,133 @@
+; mainargs.s
 ;
 ; Ullrich von Bassewitz, 2003-03-07
+; Based on code from Stefan A. Haubenthal <polluks@web.de>, 2003-11-08
+; Greg King, 2003-05-18
 ;
-; Setup arguments for main
+; Scan a group of arguments that are in BASIC's input-buffer.
+; Build an array that points to the beginning of each argument.
+; Send, to main(), that array and the count of the arguments.
+
+; Command-lines look like these lines:
+;
+; call2048
+; call2048 : rem  no arguments because no comma!
+; call2048:rem,arg1," arg 2" , arg 3 ,, arg5, ...
+;
+; "call" and "rem" are entokenned; the args. are not.  Leading spaces are
+; ignored; trailing spaces are included -- unless the argument was quoted.
+
+; TO-DO:
+; - The "file-name" might be a path-name; don't copy the directory-components.
+; - Add a control-character quoting mechanism.
+
+       .constructor    initmainargs, 24
+       .import         __argc, __argv
+
+       .include        "apple2.inc"
+
+; Maximum number of arguments allowed in the argument table.
+; (An argument contains a comma, at least.)
+;
+BASIC_BUF = $200
+BASIC_BUF_LEN = 239
+FNAM_LEN = $280
+FNAM = $281
+MAXARGS         = BASIC_BUF_LEN - 2    ; (don't count REM and terminating '\0')
+
+REM     = $b2                  ; BASIC token-code
+NAME_LEN = 15                  ; maximum length of command-name
+
+; Get possible command-line arguments.
 ;
+initmainargs:
 
+; Assume that the program was loaded, a moment ago, by the traditional LOAD
+; statement.  Save the "most-recent filename" as argument #0.
+; Because the buffer, that we're copying into, was zeroed out,
+; we don't need to add a NUL character.
+;
+       ldy     FNAM_LEN
+       cpy     #NAME_LEN + 1
+       bcc     L1
+       ldy     #NAME_LEN - 1   ; limit the length
+L0:    lda     FNAM,y
+       sta     name,y
+L1:    dey
+       bpl     L0
+       lda     #<name
+       ldx     #>name
+       sta     argv
+       stx     argv + 1
+       inc     __argc          ; argc always is equal to, at least, 1
 
-       .constructor    initmainargs, 24
-               .import         __argc, __argv
+; Find the "rem" token.
+;
+       ldx     #0
+L2:    lda     BASIC_BUF,x
+       beq     done            ; no "rem," no args.
+       inx
+       cmp     #REM
+       bne     L2
+       ldy     #1 * 2
 
+; Find the next argument.
+;
+next:  lda     BASIC_BUF,x
+       beq     done
+       inx
+       cmp     #','            ; look for argument-list separator
+       bne     next
+       lda     #$00
+       sta     BASIC_BUF-1,x   ; make the previous arg. be a legal C string
+       inc     __argc          ; found another arg.
 
-;---------------------------------------------------------------------------
-; Setup arguments for main
+L4:    lda     BASIC_BUF,x
+       beq     point           ; zero-length argument
+       inx
+       cmp     #' '
+       beq     L4              ; skip leading spaces
 
-.proc   initmainargs
+       cmp     #'"'            ; is argument quoted?
+       beq     L5
+       dex                     ; no, don't skip over character
+       clc                     ; (quotation-mark sets flag)
+L5:    ror     quoted          ; save it
 
-        rts
+; BASIC's input-buffer starts at the beginning of a RAM page.
+; So, we don't need to add the offset -- just store it.
+;
+point: txa
+       sta     argv,y          ; argv[y]= &arg
+       iny
+       lda     #>BASIC_BUF
+       sta     argv,y
+       iny
 
-.endproc
+       asl     quoted          ; is argument a string-literal?
+       bcc     next            ; no, don't look for ending quotation-mark
+L7:    lda     BASIC_BUF,x
+       beq     done
+       inx
+       cmp     #'"'
+       bne     L7
+       lda     #$00
+       sta     BASIC_BUF-1,x   ; make this arg. be a legal C string
+       beq     next            ;(bra)
 
+; (The last vector in argv[] already is NULL.)
+;
+done:  lda     #<argv
+       ldx     #>argv
+       sta     __argv
+       stx     __argv + 1
+       rts
 
+; These arrays are zeroed before initmainargs is called.
+; char name[16+1];
+; char* argv[MAXARGS+1]={name};
+;
+       .bss
+quoted:        .res    1, %00000000
+name:  .res    NAME_LEN + 1
+argv:  .res    (MAXARGS + 1) * 2