initmainargs routine by Stefan Haubenthal.

git-svn-id: svn://svn.cc65.org/cc65/trunk@3949 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/pet/crt0.s b/libsrc/pet/crt0.s
index 89582885e26403f013bb24d11caa4b3a8287e289..1d5641a7c75efec33b5511d297245a20cf444526 100644 (file)
--- a/libsrc/pet/crt0.s
+++ b/libsrc/pet/crt0.s
@@ -42,11 +42,19 @@ L1: lda     sp,x
 
        jsr     CLRCH
 
-; Switch to second charset
-
+; Switch to second charset. The routine that is called by BSOUT to switch the
+; character set will use FNLEN as temporary storage - YUCK! Since the
+; initmainargs routine, which parses the command line for arguments needs this
+; information, we need to save and restore it here.
+; Thanks to Stefan Haubenthal for this information!
+
+        lda     FNLEN
+        pha                     ; Save FNLEN
        lda     #14
 ;      sta     $E84C           ; See PET FAQ
        jsr     BSOUT
+        pla
+        sta     FNLEN           ; Restore FNLEN
 
 ; Clear the BSS data
 

diff --git a/libsrc/pet/mainargs.s b/libsrc/pet/mainargs.s
index a9233382f0ed81ad1b7cfedd681a34d9d5068382..a5892a49c1e5879c8c968a145b12512cb72db52e 100644 (file)
--- a/libsrc/pet/mainargs.s
+++ b/libsrc/pet/mainargs.s
@@ -1,24 +1,125 @@
 ;
 ; Ullrich von Bassewitz, 2003-03-07
+; Stefan Haubenthal, 2008-08-11
 ;
 ; Setup arguments for main
 ;
 
+       .constructor    initmainargs, 24
+       .import         __argc, __argv
 
-       .constructor    initmainargs, 24
-               .import         __argc, __argv
+       .include        "pet.inc"
+
+MAXARGS         = 10                   ; Maximum number of arguments allowed
+REM     = $8f                  ; BASIC token-code
+NAME_LEN = 16                  ; maximum length of command-name
+BASIC_BUF= $200
 
 
 ;---------------------------------------------------------------------------
 ; Get possible command-line arguments. Goes into the special INIT segment,
 ; which may be reused after the startup code is run
 
-.segment        "INIT"
+.segment       "INIT"
+
+.proc  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     FNLEN
+       cpy     #NAME_LEN + 1
+       bcc     L1
+       ldy     #NAME_LEN - 1   ; limit the length
+L0:    lda     (FNADR),y
+       sta     name,y
+L1:    dey
+       bpl     L0
+       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.
+       inx
+       cmp     #REM
+       bne     L2
+       ldy     #1 * 2
+
+; Find the next argument
+
+next:  lda     BASIC_BUF,x
+       beq     done            ; End of line reached
+       inx
+       cmp     #' '            ; Skip leading spaces
+       beq     next            ;
+
+; 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
 
-.proc   initmainargs
+; 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.
 
-        rts
+       txa                     ; Get low byte
+       sta     argv,y          ; argv[y]= &arg
+       iny
+       lda     #>BASIC_BUF
+       sta     argv,y
+       iny
+       inc     __argc          ; Found another arg
+
+; 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
+       stx     __argv + 1
+       rts
 
 .endproc
 
+; These arrays are zeroed before initmainargs is called.
+; char name[16+1];
+; char* argv[MAXARGS+1]={name};
+;
+.bss
+term:  .res    1
+name:  .res    NAME_LEN + 1
 
+.data
+argv:  .addr   name
+       .res    MAXARGS * 2