Rewrote argument parsing

git-svn-id: svn://svn.cc65.org/cc65/trunk@2984 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/c64/mainargs.s b/libsrc/c64/mainargs.s
index 268d091597f6cb8e51555cfb08c8c82a5cdcf63a..ffd396cf99f8d7d591a6c1c71ec64accee804587 100644 (file)
--- a/libsrc/c64/mainargs.s
+++ b/libsrc/c64/mainargs.s
@@ -26,11 +26,9 @@
 
        .include        "c64.inc"
 
-; Maximum number of arguments allowed in the argument table.
-; (An argument contains a comma, at least.)
-;
-MAXARGS         = BASIC_BUF_LEN - 2    ; (don't count REM and terminating '\0')
 
+
+MAXARGS         = 10                   ; Maximum number of arguments allowed
 REM     = $8f                  ; BASIC token-code
 NAME_LEN = 16                  ; maximum length of command-name
 
@@ -51,68 +49,73 @@ 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
+       inc     __argc          ; argc always is equal to, at least, 1
 
 ; Find the "rem" token.
 ;
        ldx     #0
 L2:    lda     BASIC_BUF,x
-       beq     done            ; no "rem," no args.
+               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.
-
-L4:    lda     BASIC_BUF,x
-       beq     point           ; zero-length argument
-       inx
-       cmp     #' '
-       beq     L4              ; skip leading spaces
+; Find the next argument
 
-       cmp     #'"'            ; is argument quoted?
-       beq     L5
-       dex                     ; no, don't skip over character
-       clc                     ; (quotation-mark sets flag)
-L5:    ror     quoted          ; save it
+next:   lda     BASIC_BUF,x
+        beq     done            ; End of line reached
+        inx
+        cmp     #' '            ; Skip leading spaces
+        beq     next            ;
 
-; 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
+; Found start of next argument. We've incremented the pointer in X already, so
+; it points to the second character of the argument. This is useful since we
+; will check now for a quoted argument, in which case we will have to skip this
+; first character.
+
+found:  cmp     #'"'            ; Is the argument quoted?
+        beq     setterm         ; Jump if so
+        dex                     ; Reset pointer to first argument character
+        lda     #' '            ; A space ends the argument
+setterm:sta     term            ; Set end of argument marker
+
+; Now store a pointer to the argument into the next slot. Since the BASIC
+; input buffer is located at the start of a RAM page, no calculations are
+; necessary.
+
+        txa                     ; Get low byte
        sta     argv,y          ; argv[y]= &arg
        iny
        lda     #>BASIC_BUF
        sta     argv,y
        iny
+        inc     __argc          ; Found another arg
 
-       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)
+; Search for the end of the argument
+
+argloop:lda     BASIC_BUF,x
+        beq     done
+        inx
+        cmp     term
+        bne     argloop
+
+; We've found the end of the argument. X points one character behind it, and
+; A contains the terminating character. To make the argument a valid C string,
+; replace the terminating character by a zero.
+
+        lda     #0
+        sta     BASIC_BUF-1,x
+
+; Check if the maximum number of command line arguments is reached. If not,
+; parse the next one.
+
+        lda     __argc          ; Get low byte of argument count
+        cmp     #MAXARGS        ; Maximum number of arguments reached?
+        bcc     next            ; Parse next one if not
 
 ; (The last vector in argv[] already is NULL.)
-;
+
 done:  lda     #<argv
        ldx     #>argv
        sta     __argv
@@ -123,7 +126,11 @@ done:      lda     #<argv
 ; char name[16+1];
 ; char* argv[MAXARGS+1]={name};
 ;
-       .bss
-quoted:        .res    1, %00000000
+.bss
+term:  .res    1
 name:  .res    NAME_LEN + 1
-argv:  .res    (MAXARGS + 1) * 2
+
+.data
+argv:   .addr   name
+        .res           MAXARGS * 2
+