;; exit to the calling definition via "jmp exit".
jmp qword rsi
+ WORD p_exit, 'EXIT',fasm
+ ;; ( -- ) ( R: addr -- )
+ ;; Returns execution to the calling definition as per the
+ ;; return stack.
+exit:
+ popr rsi
+ next
+
;;; Execution semantics for FORTH defition word
;;; At entry, rsi points into the calling definition, at the cell
;;; following the cell indicating this word, rax points to the CFA of
lea rsi, [rax+8] ; rsi = the DFA of the rax word
next
- WORD p_exit, 'EXIT',fasm
- ;; ( -- ) ( R: addr -- )
- ;; Returns execution to the calling definition as per the
- ;; return stack.
-exit:
- popr rsi
+;;; Execution semantics for DOES>
+;;; The cell at [cfa-8] holds an adjustment offset.
+dodoes:
+ pushr rsi
+ lea rsi, [rax+8] ; rsi = the DFA of the rax word
+ add rsi,[rax-8] ; adjust rsi to the DOES> part
next
;; Execution semantics for a variable ( -- addr )
- ;; rax points to doer field
+ ;; rax points to CFA field
dovariable:
- push rax+16
+ add rax,8
+ push rax
next
;; Execution semantics for a constant ( -- v )
- ;; rax points to doer field
+ ;; rax points to CFA field
dovalue:
- push qword [rax+16]
+ push qword [rax+8]
next
;; Execution semantics for a string constant ( -- addr n )
- ;; rax points to doer field
+ ;; rax points to CFA field
dostring:
- add rax,16
+ add rax,8
+ xor rbx,rbx
mov bl,[rax]
- mov byte [rsp],bl
- push rax+1
+ inc rax
+ push rax
+ push rbx
next
include 'wordlists.asm'
include 'stdio.asm'
WORD p_program_version,'PROGRAM_VERSION',dostring
- db length
-program_version_string:
- db 'RRQ Forth version 0.1 - 2021-05-13',10
- length = $ - program_version_string
+ STRING 'RRQ Forth version 0.1 - 2021-05-13',10
WORD p_stdin,'STDIN',dovalue
;; Initialised to hold a STREAM for fd 0
DOFORTH p_stream
pop qword [p_stdin_DFA]
- ;; read a word
- push qword 1 ; ( fd ) =stdout
- push qword [p_stdin_DFA]
- FORTH
- dq p_read_word ; ( fd s n )
- dq sys_write
- ENDFORTH
-
+ ;; Initial blurb
push qword 1 ; stdout
- push qword program_version_string ; address of string
- push qword length ; length of string (cheating)
+ DOFORTH p_program_version ; version string => ( s n )
DOFORTH sys_write ; printout
pop rax ; ignore errors
+
+ DOFORTH p_words
push 0
DOFORTH sys_exit