mango/host/assembler.fnl

46 lines
1.3 KiB
Fennel

(local
{: r
: move
: branch
: branch-link}
(require :host.assembler.opcodes))
(local {: any : slice : push : map} (require :deps.lume))
(local {: word->byte} (require :host.util))
(local {: emulate} (require :host.util.emulator))
(fn label [name] {:label name})
(fn label? [value]
(if (and (= (type value) :table) (. value :label)) true false))
(fn insert-label [table label index]
(if (. table :label)
(:error (.. "Duplicate label " label))
(tset table :labels label index)))
(fn assemble [forms offset]
(let [state {:labels {} :instructions [] :reverse-labels []}]
(each [_ form (ipairs forms)]
(if (= (type form) :string)
(insert-label state form (+ offset (* 4 (length (. state :instructions)))))
(push (. state :instructions)
(if (any (slice form 2) label?)
(do
(push (. state :reverse-labels) (+ 1 (length (. state :instructions))))
form)
((. form 1) (table.unpack (slice form 2)))))))
state))
; (fn link [{: labels : instructions : reverse-labels}]
; ())
(assemble
[[move (r 8) (r 2)]
:label-1
[move (r 9) (r 3)]
[branch (label :label-1)]]
0x8000)
(let [assembly (assemble [[move (r 8) 127]])
byte-string (table.concat (map (. assembly :instructions) word->byte) "")]
(emulate byte-string))