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cc65/libsrc/c16/mainargs.s
uz 5c5d01d84a Moved most platform assembler includes into asminc, so they will be available
in the distribution. 
Added --forget-inc-paths to the command line of the assembler in the
Makefiles, because the assembler does now have builtin paths and will find
include files from an installation first.
Hopefully fixed any problems that arose from the two changes.


git-svn-id: svn://svn.cc65.org/cc65/trunk@4223 b7a2c559-68d2-44c3-8de9-860c34a00d81
2009-09-24 17:44:22 +00:00

142 lines
3.8 KiB
ArmAsm

; mainargs.s
;
; Ullrich von Bassewitz, 2003-03-07
; Based on code from Stefan A. Haubenthal, <polluks@web.de>
; 2003-05-18, Greg King
; 2004-04-28, 2005-02-26, Ullrich von Bassewitz
;
; 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:
;
; run
; run : rem
; run:rem arg1 " arg 2 is quoted " arg3 "" arg5
;
; "run" and "rem" are entokenned; the args. are not. Leading and trailing
; spaces outside of quotes are ignored.
;
; 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 "plus4.inc"
MAXARGS = 10 ; Maximum number of arguments allowed
REM = $8f ; BASIC token-code
NAME_LEN = 16 ; maximum length of command-name
; Get possible command-line arguments. Goes into the special INIT segment,
; which may be reused after the startup code is run
.segment "INIT"
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 ; Vector address
jsr FETCH ; Load byte from RAM
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
; 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
; 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
; 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