mirror of
https://github.com/cc65/cc65.git
synced 2024-12-27 00:29:31 +00:00
189 lines
4.1 KiB
ArmAsm
189 lines
4.1 KiB
ArmAsm
;
|
|
; int __fastcall__ vsscanf (const char* str, const char* format, va_list ap);
|
|
; /* Standard C function */
|
|
;
|
|
; 2004-11-28, Ullrich von Bassewitz
|
|
; 2004-12-21, Greg King
|
|
;
|
|
|
|
.export _vsscanf
|
|
|
|
.import popax, __scanf
|
|
.importzp sp, ptr1, ptr2
|
|
|
|
.macpack generic
|
|
|
|
|
|
; ----------------------------------------------------------------------------
|
|
; Structure used to pass data to the callback functions
|
|
|
|
.struct SSCANFDATA
|
|
STR .addr
|
|
INDEX .word
|
|
.endstruct
|
|
|
|
|
|
; ----------------------------------------------------------------------------
|
|
; static int __fastcall__ get (struct sscanfdata* d)
|
|
; /* Read a character from the input string and return it */
|
|
; {
|
|
; char C = d->str[d->index];
|
|
; if (C == '\0') {
|
|
; return EOF;
|
|
; }
|
|
; /* Increment index only if end not reached */
|
|
; ++d->index;
|
|
; return C;
|
|
; }
|
|
;
|
|
|
|
.code
|
|
.proc get
|
|
|
|
sta ptr1
|
|
stx ptr1+1 ; Save d
|
|
|
|
; Get d->str adding the high byte of index to the pointer, so we can access
|
|
; the byte in the string with just the low byte as index
|
|
|
|
ldy #SSCANFDATA::STR
|
|
lda (ptr1),y
|
|
sta ptr2
|
|
iny
|
|
lda (ptr1),y
|
|
ldy #SSCANFDATA::INDEX+1
|
|
add (ptr1),y
|
|
sta ptr2+1
|
|
|
|
; Load the low byte of the index and fetch the byte from the string
|
|
|
|
dey ; = SSCANFDATA::INDEX
|
|
lda (ptr1),y
|
|
tay
|
|
lda (ptr2),y
|
|
|
|
; Return EOF if we are at the end of the string
|
|
|
|
bne L1
|
|
lda #$FF
|
|
tax
|
|
rts
|
|
|
|
; Bump the index (beware: A contains the char we must return)
|
|
|
|
L1: tax ; Save return value
|
|
tya ; Low byte of index
|
|
ldy #SSCANFDATA::INDEX
|
|
add #<1
|
|
sta (ptr1),y
|
|
iny
|
|
lda (ptr1),y
|
|
adc #>1
|
|
sta (ptr1),y
|
|
|
|
; Return the char just read
|
|
|
|
txa
|
|
ldx #>0
|
|
rts
|
|
|
|
.endproc
|
|
|
|
; ----------------------------------------------------------------------------
|
|
; static int __fastcall__ unget (int c, struct sscanfdata* d)
|
|
; /* Push back a character onto the input stream */
|
|
; {
|
|
; /* We do assume here that the _scanf routine will not push back anything
|
|
; * not read, so we can ignore c safely and won't check the index.
|
|
; */
|
|
; --d->index;
|
|
; return c;
|
|
; }
|
|
;
|
|
|
|
.code
|
|
.proc unget
|
|
|
|
sta ptr1
|
|
stx ptr1+1 ; Save d
|
|
|
|
; Decrement the index
|
|
|
|
ldy #SSCANFDATA::INDEX
|
|
lda (ptr1),y
|
|
sub #<1
|
|
sta (ptr1),y
|
|
iny
|
|
lda (ptr1),y
|
|
sbc #>1
|
|
sta (ptr1),y
|
|
|
|
; Return c
|
|
|
|
jmp popax
|
|
|
|
.endproc
|
|
|
|
; ----------------------------------------------------------------------------
|
|
; int __fastcall__ vsscanf (const char* str, const char* format, va_list ap)
|
|
; /* Standard C function */
|
|
; {
|
|
; /* Initialize the data structs. The sscanfdata struct will be passed back
|
|
; * to the get and unget functions by _scanf().
|
|
; */
|
|
; static struct sscanfdata sd;
|
|
; static const struct scanfdata d = {
|
|
; ( getfunc) get,
|
|
; (ungetfunc) unget,
|
|
; (void*) &sd
|
|
; };
|
|
;
|
|
; sd.str = str;
|
|
; sd.index = 0;
|
|
;
|
|
; /* Call the internal function and return the result */
|
|
; return _scanf (&d, format, ap);
|
|
; }
|
|
;
|
|
|
|
.bss
|
|
sd: .tag SSCANFDATA
|
|
|
|
.rodata
|
|
d: .addr get
|
|
.addr unget
|
|
.addr sd
|
|
|
|
.code
|
|
.proc _vsscanf
|
|
|
|
; Save the low byte of ap (which is passed in a/x)
|
|
|
|
pha
|
|
|
|
; Initialize sd and at the same time replace str on the stack by a pointer
|
|
; to d
|
|
|
|
ldy #2 ; Stack offset of str
|
|
lda (sp),y
|
|
sta sd + SSCANFDATA::STR
|
|
lda #<d
|
|
sta (sp),y
|
|
iny
|
|
lda (sp),y
|
|
sta sd + SSCANFDATA::STR+1
|
|
lda #>d
|
|
sta (sp),y
|
|
|
|
lda #$00
|
|
sta sd + SSCANFDATA::INDEX
|
|
sta sd + SSCANFDATA::INDEX+1
|
|
|
|
; Restore the low byte of ap, and jump to _scanf() which will clean up the stack
|
|
|
|
pla
|
|
jmp __scanf
|
|
|
|
.endproc
|
|
|