application/octet-stream
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7.44 KB
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211 lines
;; Nujel - Copyright (C) 2020-2021 - Benjamin Vincent Schulenburg
;; This project uses the MIT license, a copy should be included under /LICENSE
;;
;; Contains the bytecode assembler, so we don't have to write opcodes directly
[defn val->bytecode-op [v]
[def i [val->index v]]
[list [int->bytecode-op [logand [>> i 16] #xFF]]
[int->bytecode-op [logand [>> i 8] #xFF]]
[int->bytecode-op [logand i #xFF]]]]
[defn sym->bytecode-op [v]
[def i [sym->index v]]
[list [int->bytecode-op [logand [>> i 16] #xFF]]
[int->bytecode-op [logand [>> i 8] #xFF]]
[int->bytecode-op [logand i #xFF]]]]
[defn int-fit-in-byte? [a]
[and [<= a 127] [>= a -128]]]
[defn $push/int [a]
"[] -> [a]"
"Push A on the stack as an :int"
[if [int-fit-in-byte? a]
[$push/int/byte a]
[$push/lval a]]]
[defn $push/int/byte [a]
"[] -> [a]"
"Push A on the stack as an :int that fits within a byte"
[when-not [int-fit-in-byte? a]
[throw [list :invalid-bc-op "$push/int/byte can only push a signed 8-bit value" a [current-lambda]]]]
[list #$2 [int->bytecode-op a]]]
[defn $push/lval [v]
"[] -> [v]"
"Pushes v onto the stack"
[when [nil? v]
[throw [list :invalid-bc-op "Can't push #nil as a normal lVal" v [current-lambda]]]]
[list #$5 [val->bytecode-op v]]]
[defn $push/symbol [sym]
"[] -> [sym]"
"Pushes v onto the stack"
[list #$23 [sym->bytecode-op sym]]]
[defn $def [sym]
"[val] -> [val]"
"Define a new binding for SYM and associate VAL to it"
[list #$E [sym->bytecode-op sym]]]
[defn $set [sym]
"[val] -> [val]"
"Update the binding for SYM and associate VAL to it"
[list #$F [sym->bytecode-op sym]]]
[defn $get [sym]
"[] -> [val]"
"Push whatever value is associated to SYM on the stack"
[list #$10 [sym->bytecode-op sym]]]
[defn $apply/optimize? [fun arg-count]
[case fun
[[+ - * / rem] [= arg-count 2]]
[[zero? car cdr add/int cons < <= = >= >] #t]]]
[defn $apply [arg-count fun]
"arguments -> [result]"
"Read arg-count arguments from the stack, apply the to fun and push the result on the stack"
[case arg-count
[1 [case fun
[car [$car]]
[cdr [$cdr]]
[zero? [$zero?]]
[otherwise [exception :arity-error "Wrong number of arguments for that function" fun]]]]
[2 [case fun
[add/int [$add/int]]
[+ [$add]]
[- [$sub]]
[* [$mul]]
[/ [$div]]
[rem [$rem]]
[cons [$cons]]
[< [$<]]
[<= [$<=]]
[= [$=]]
[>= [$>=]]
[> [$>]]
[otherwise [exception :arity-error "Wrong number of arguments for that function" fun]]]]
[otherwise [exception :arity-error "Wrong number of arguments for that function" fun]]]]
[defn $apply/dynamic [arg-count fun]
[list #$4
[int->bytecode-op arg-count]]]
[defn $try [target]
"[] -> []"
"Try something, jumping to target if an exception occurs"
[list #$19 [list :relocate target 8 0 [int->bytecode-op 0]]
[list :relocate target 0 1 [int->bytecode-op 0]]]]
[defn $jmp [target]
[list #$9
[list :relocate target 8 0 [int->bytecode-op 0]]
[list :relocate target 0 1 [int->bytecode-op 0]]]]
[defn $push/val [v]
"[] -> [v]"
"Pushes v onto the stack"
[when [nil? v]
[throw [list :invalid-bc-op "Can't push #nil as a normal lVal" v [current-lambda]]]]
[list #$1A
[list :literal v]]]
[defn $jt [target]
[list #$A
[list :relocate target 8 0 [int->bytecode-op 0]]
[list :relocate target 0 1 [int->bytecode-op 0]]]]
[defn $jf [target]
[list #$B
[list :relocate target 8 0 [int->bytecode-op 0]]
[list :relocate target 0 1 [int->bytecode-op 0]]]]
[defn $fn [name args docs body]
[list #$25
[val->bytecode-op name]
[val->bytecode-op args]
[val->bytecode-op docs]
[val->bytecode-op body]]]
[defn $macro* [name args docs body]
[list #$26
[val->bytecode-op name]
[val->bytecode-op args]
[val->bytecode-op docs]
[val->bytecode-op body]]]
[defn assemble/build-sym-map [code sym-map pos]
[while code
[case [type-of [car code]]
[:bytecode-op [tree/set! sym-map :last-op [inc! pos]]]
[[:symbol :keyword] [and [= [car code] :label]
[tree/set! sym-map [cadr code] pos]]]
[:pair [set! pos [assemble/build-sym-map [car code] sym-map pos]]]]
[cdr! code]]
[when [zero? 123] 123]
[return pos]]
[defn assemble/relocate-op [code sym-map pos out]
[def target [tree/ref sym-map [cadr code]]]
[def off [- [+ target [cadddr code]] pos]]
[array/set! out [inc! pos] [int->bytecode-op [logand [>> off [caddr code]] #xFF]]]
[return pos]]
[defn assemble/emit-relocated-ops [code sym-map pos out]
[if [= [car code] :relocate]
[set! pos [assemble/relocate-op code sym-map pos out]]
[doseq [op code]
[case [type-of op]
[:bytecode-op [array/set! out [inc! pos] op]]
[:pair [set! pos [assemble/emit-relocated-ops op sym-map pos out]]]]]]
[return pos]]
[defn assemble/add-literal [code lit-arr]
[when [>= [array/length lit-arr] 255]
[exception :out-of-bounds "Can only store up to 255 literals per bytecode-arr" code]]
[array/length! lit-arr [+ 1 [array/length lit-arr]]]
[array/set! lit-arr [- [array/length lit-arr] 1] [cadr code]]
[int->bytecode-op [- [array/length lit-arr] 1]]]
[defn assemble/build-lit-arr [code lit-arr]
[when-not code [return #nil]]
[cons [cond [[pair? [car code]]
[assemble/build-lit-arr [car code] lit-arr]]
[[= :literal [car code]]
[assemble/add-literal code lit-arr]]
[#t [car code]]]
[assemble/build-lit-arr [cdr code] lit-arr]]]
[defn assemble/flatten [code ret]
[when-not code [return ret]]
[when-not [pair? code] [return ret]]
[set! ret [assemble/flatten [cdr code] ret]]
[if [and [pair? [car code]]
[not [keyword? [caar code]]]]
[assemble/flatten [car code] ret]
[cons [car code] ret]]]
[defn assemble* [code]
"Assemble all arguments into a single :bytecode-array"
[def sym-map @[]]
[def lit-arr #[]]
[def tmp [-> [assemble/flatten code]
[assemble/build-lit-arr lit-arr]]]
[assemble/build-sym-map tmp sym-map 0]
[def out [array/allocate [tree/ref sym-map :last-op]]]
[assemble/emit-relocated-ops tmp sym-map -1 out]
[arr->bytecode-arr out lit-arr]]
[defn assemble l
"Assemble all arguments into a single :bytecode-array"
[assemble* l]]
[defmacro asmrun ops
"Assemble and evaluate all bytecode arguments"
`[apply [current-closure]
[assemble ~@ops]]]
[defn bytecode-eval [bc env]
[apply [or env [current-closure]] bc]]
