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;
; Ullrich von Bassewitz, 2002-12-16
;
; __sigfunc __fastcall__ signal (int sig, __sigfunc func);
;
.import popax
.importzp ptr1
.include "signal.inc"
.include "errno.inc"
; Default signal functions: The standard specifies explicitly that the values
; for SIG_IGN and SIG_DFL must be distinct, so we make them so by using both
; rts exits we have. This works because signal functions are __fastcall__, so
; we don't have arguments on the stack.
;----------------------------------------------------------------------------
; __sigfunc __fastcall__ signal (int sig, __sigfunc func);
_signal:
sta ptr1
stx ptr1+1 ; Remember func
jsr popax ; Get sig
cpx #0
bne invalidsig
cmp #SIGCOUNT
bcs invalidsig
; Signal number is valid. Replace the pointer in the table saving the old
; value temporarily on the stack.
asl a ; Prepare for word access
tax
sei ; Disable interrupts in case of async signals
lda sigtable,x
pha
lda ptr1
sta sigtable,x
lda sigtable+1,x
pha
lda ptr1+1
sta sigtable+1,x
cli ; Reenable interrupts
; Get the old value from the stack and return it
pla
tax
pla
__sig_ign:
rts
; Error entry: We use our knowledge that SIG_ERR is zero here to save a byte
invalidsig:
lda #<EINVAL
jsr __seterrno ; Returns 0 in A
tax ; A/X = 0
__sig_dfl:
rts
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