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wasm-vm-runtime.oak
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1995 lines (1843 loc) · 77.1 KB
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// wasm-vm-runtime -- WebAssembly Text format VM runtime generator
//
// Generates a complete, self-contained WAT module that contains a bytecode
// interpreter for Oak programs. The module embeds compiled bytecode,
// a constant pool, and function templates in linear memory, and implements
// a stack-based VM that executes them without requiring an external Oak
// interpreter.
//
// Host imports required (minimal I/O only):
// env.print_string(ptr, len) — write bytes to stdout
// env.exit(code) — terminate execution
//
// Memory layout (offsets computed per-program):
// [0x0000 .. VSTACK_END) Value stack — 8 bytes per entry (type:i32, val:i32)
// [VSTACK_END .. CSTACK_END) Call/frame stack
// [CSTACK_END .. BYTECODE_END) Bytecode program
// [BYTECODE_END .. CONSTPOOL_END) Constant pool
// [CONSTPOOL_END .. FNTABLE_END) Function template table
// [FNTABLE_END .. ) Heap (bump-allocated, grows upward)
std := import('std')
map := std.map
each := std.each
len := std.len
str := import('str')
join := str.join
fmt := import('fmt')
format := fmt.format
// Memory region sizes (in bytes)
VSTACK_SIZE := 16384 // 16KB = 2048 value slots
CSTACK_SIZE := 16384 // 16KB for call frames
PAGE_SIZE := 65536 // WASM page = 64KB
// generateVMWat produces the complete WAT source for the VM module.
//
// Parameters:
// bytecodeWAT — WAT-escaped bytecode data string
// bytecodeLen — byte length of bytecode
// constpoolWAT — WAT-escaped constant pool data string
// constpoolLen — byte length of constant pool
// fntableWAT — WAT-escaped function table data string
// fntableLen — byte length of function table
fn generateVMWat(bytecodeWAT, bytecodeLen, constpoolWAT, constpoolLen, fntableWAT, fntableLen) {
// Compute memory addresses
vstackBase := 0
vstackEnd := vstackBase + VSTACK_SIZE
cstackBase := vstackEnd
cstackEnd := cstackBase + CSTACK_SIZE
bytecodeBase := cstackEnd
bytecodeEnd := bytecodeBase + bytecodeLen
constpoolBase := bytecodeEnd
constpoolEnd := constpoolBase + constpoolLen
fntableBase := constpoolEnd
fntableEnd := fntableBase + fntableLen
heapStart := fntableEnd
// Align heap to 16-byte boundary
heapStart <- if heapStart % 16 > 0 {
true -> heapStart + 16 - (heapStart % 16)
_ -> heapStart
}
totalBytes := heapStart + 65536 // 64KB initial heap
memoryPages := int(totalBytes / PAGE_SIZE)
if totalBytes % PAGE_SIZE > 0 -> memoryPages <- memoryPages + 1
if memoryPages < 1 -> memoryPages <- 1
// Helper to emit i32.const
fn ic(v) 'i32.const ' << string(v)
// Build the WAT module
';; Oak WASM VM — generated by oak build --wasm
;; Bytecode VM: no external Oak interpreter required
(module
;; ---- Host imports (I/O only) ----
(import "env" "print_string" (func $host_print (param i32 i32)))
(import "env" "exit" (func $host_exit (param i32)))
;; ---- Memory ----
(memory (export "memory") ' << string(memoryPages) << ')
;; ---- Data segments ----
;; Bytecode at offset ' << string(bytecodeBase) << '
(data (' << ic(bytecodeBase) << ') "' << bytecodeWAT << '")
;; Constant pool at offset ' << string(constpoolBase) << '
(data (' << ic(constpoolBase) << ') "' << constpoolWAT << '")
;; Function table at offset ' << string(fntableBase) << '
(data (' << ic(fntableBase) << ') "' << fntableWAT << '")
;; ---- Globals ----
(global $pc (mut i32) (' << ic(bytecodeBase) << ')) ;; program counter (absolute addr)
(global $sp (mut i32) (' << ic(vstackBase) << ')) ;; value stack pointer
(global $csp (mut i32) (' << ic(cstackBase) << ')) ;; call stack pointer
(global $hp (mut i32) (' << ic(heapStart) << ')) ;; heap pointer
;; Memory layout constants (exported for host inspection)
(global $vstack_base (export "vstack_base") i32 (' << ic(vstackBase) << '))
(global $cstack_base (export "cstack_base") i32 (' << ic(cstackBase) << '))
(global $bytecode_base (export "bytecode_base") i32 (' << ic(bytecodeBase) << '))
(global $constpool_base(export "constpool_base")i32 (' << ic(constpoolBase) << '))
(global $fntable_base (export "fntable_base") i32 (' << ic(fntableBase) << '))
(global $heap_start (export "heap_start") i32 (' << ic(heapStart) << '))
;; ---- Bump allocator ----
(func $alloc (param $size i32) (result i32)
(local $ptr i32)
;; Align size to 8 bytes
(local.set $size (i32.and
(i32.add (local.get $size) (i32.const 7))
(i32.const -8)))
(local.set $ptr (global.get $hp))
(global.set $hp (i32.add (global.get $hp) (local.get $size)))
;; Grow memory if needed
(if (i32.gt_u (global.get $hp) (i32.mul (memory.size) (i32.const 65536)))
(then
(drop (memory.grow (i32.const 1)))
)
)
(local.get $ptr)
)
;; ---- Value stack operations ----
;; Each stack entry is 8 bytes: [type:i32 @ sp+0] [payload:i32 @ sp+4]
(func $push_val (param $type i32) (param $val i32)
(i32.store (global.get $sp) (local.get $type))
(i32.store (i32.add (global.get $sp) (i32.const 4)) (local.get $val))
(global.set $sp (i32.add (global.get $sp) (i32.const 8)))
)
(func $peek_type (result i32)
(i32.load (i32.sub (global.get $sp) (i32.const 8)))
)
(func $peek_val (result i32)
(i32.load (i32.sub (global.get $sp) (i32.const 4)))
)
(func $pop_type (result i32)
(global.set $sp (i32.sub (global.get $sp) (i32.const 8)))
(i32.load (global.get $sp))
)
(func $pop_val (result i32)
;; Must be called immediately after pop_type
(i32.load (i32.add (global.get $sp) (i32.const 4)))
)
;; Pop a full tagged value, returning type in first result
;; We use a global to pass the second value since WASM MVP has single returns
(global $tmp_val (mut i32) (i32.const 0))
(func $pop_tagged (result i32)
(local $t i32)
(global.set $sp (i32.sub (global.get $sp) (i32.const 8)))
(local.set $t (i32.load (global.get $sp)))
(global.set $tmp_val (i32.load (i32.add (global.get $sp) (i32.const 4))))
(local.get $t)
)
;; ---- Bytecode fetch helpers ----
(func $fetch_u8 (result i32)
(local $v i32)
(local.set $v (i32.load8_u (global.get $pc)))
(global.set $pc (i32.add (global.get $pc) (i32.const 1)))
(local.get $v)
)
(func $fetch_u16 (result i32)
(local $lo i32)
(local $hi i32)
(local.set $lo (i32.load8_u (global.get $pc)))
(local.set $hi (i32.load8_u (i32.add (global.get $pc) (i32.const 1))))
(global.set $pc (i32.add (global.get $pc) (i32.const 2)))
(i32.or (local.get $lo) (i32.shl (local.get $hi) (i32.const 8)))
)
(func $fetch_i32 (result i32)
(local $v i32)
(local.set $v (i32.load (global.get $pc)))
(global.set $pc (i32.add (global.get $pc) (i32.const 4)))
(local.get $v)
)
;; ---- Heap string helpers ----
;; Heap string format: [len:i32][byte0 byte1 ...]
(func $alloc_string (param $src i32) (param $slen i32) (result i32)
(local $ptr i32)
(local.set $ptr (call $alloc (i32.add (local.get $slen) (i32.const 4))))
(i32.store (local.get $ptr) (local.get $slen))
(call $memcpy
(i32.add (local.get $ptr) (i32.const 4))
(local.get $src)
(local.get $slen))
(local.get $ptr)
)
(func $string_len (param $ptr i32) (result i32)
(i32.load (local.get $ptr))
)
(func $string_data (param $ptr i32) (result i32)
(i32.add (local.get $ptr) (i32.const 4))
)
;; ---- Memory copy ----
(func $memcpy (param $dst i32) (param $src i32) (param $n i32)
(local $i i32)
(local.set $i (i32.const 0))
(block $done
(loop $copy
(br_if $done (i32.ge_u (local.get $i) (local.get $n)))
(i32.store8
(i32.add (local.get $dst) (local.get $i))
(i32.load8_u (i32.add (local.get $src) (local.get $i))))
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $copy)
)
)
)
;; ---- String comparison ----
(func $str_eq (param $a i32) (param $b i32) (result i32)
(local $alen i32) (local $blen i32) (local $i i32)
(local.set $alen (call $string_len (local.get $a)))
(local.set $blen (call $string_len (local.get $b)))
(if (i32.ne (local.get $alen) (local.get $blen))
(then (return (i32.const 0))))
(local.set $i (i32.const 0))
(block $done
(loop $cmp
(br_if $done (i32.ge_u (local.get $i) (local.get $alen)))
(if (i32.ne
(i32.load8_u (i32.add (call $string_data (local.get $a)) (local.get $i)))
(i32.load8_u (i32.add (call $string_data (local.get $b)) (local.get $i))))
(then (return (i32.const 0))))
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $cmp)
)
)
(i32.const 1)
)
;; ---- String concatenation ----
(func $str_concat (param $a i32) (param $b i32) (result i32)
(local $alen i32) (local $blen i32) (local $ptr i32) (local $total i32)
(local.set $alen (call $string_len (local.get $a)))
(local.set $blen (call $string_len (local.get $b)))
(local.set $total (i32.add (local.get $alen) (local.get $blen)))
(local.set $ptr (call $alloc (i32.add (local.get $total) (i32.const 4))))
(i32.store (local.get $ptr) (local.get $total))
(call $memcpy
(i32.add (local.get $ptr) (i32.const 4))
(call $string_data (local.get $a))
(local.get $alen))
(call $memcpy
(i32.add (i32.add (local.get $ptr) (i32.const 4)) (local.get $alen))
(call $string_data (local.get $b))
(local.get $blen))
(local.get $ptr)
)
;; ---- String append byte ----
(func $str_append_byte (param $s i32) (param $byte i32) (result i32)
(local $slen i32) (local $ptr i32)
(local.set $slen (call $string_len (local.get $s)))
(local.set $ptr (call $alloc (i32.add (local.get $slen) (i32.const 5))))
(i32.store (local.get $ptr) (i32.add (local.get $slen) (i32.const 1)))
(call $memcpy
(i32.add (local.get $ptr) (i32.const 4))
(call $string_data (local.get $s))
(local.get $slen))
(i32.store8
(i32.add (i32.add (local.get $ptr) (i32.const 4)) (local.get $slen))
(i32.and (local.get $byte) (i32.const 255)))
(local.get $ptr)
)
;; ---- String set byte in place ----
(func $str_set_byte (param $s i32) (param $idx i32) (param $byte i32)
(if (i32.lt_u (local.get $idx) (call $string_len (local.get $s)))
(then
(i32.store8
(i32.add (call $string_data (local.get $s)) (local.get $idx))
(i32.and (local.get $byte) (i32.const 255)))
)
)
)
;; ---- List push (append value) ----
(func $list_push (param $lst i32) (param $vtype i32) (param $vval i32)
(local $len i32) (local $cap i32) (local $items i32)
(local $new_items i32) (local $new_cap i32)
(local.set $len (i32.load (local.get $lst)))
(local.set $cap (i32.load (i32.add (local.get $lst) (i32.const 4))))
(local.set $items (i32.load (i32.add (local.get $lst) (i32.const 8))))
(if (i32.ge_u (local.get $len) (local.get $cap))
(then
;; Grow: double capacity
(local.set $new_cap (i32.mul (i32.add (local.get $cap) (i32.const 1)) (i32.const 2)))
(local.set $new_items (call $alloc (i32.mul (local.get $new_cap) (i32.const 8))))
(call $memcpy (local.get $new_items) (local.get $items)
(i32.mul (local.get $len) (i32.const 8)))
(i32.store (i32.add (local.get $lst) (i32.const 4)) (local.get $new_cap))
(i32.store (i32.add (local.get $lst) (i32.const 8)) (local.get $new_items))
(local.set $items (local.get $new_items))
)
)
;; Append at position len
(call $list_set (local.get $lst) (local.get $len)
(local.get $vtype) (local.get $vval))
;; Increment length
(i32.store (local.get $lst) (i32.add (local.get $len) (i32.const 1)))
)
;; ---- Helper: set local in an explicit locals block ----
(func $set_local_at (param $locals_ptr i32) (param $idx i32)
(param $type i32) (param $val i32)
(local $base i32)
(local.set $base (i32.add
(local.get $locals_ptr)
(i32.mul (local.get $idx) (i32.const 8))))
(i32.store (local.get $base) (local.get $type))
(i32.store (i32.add (local.get $base) (i32.const 4)) (local.get $val))
)
;; ---- Constant pool access ----
;; Pool format: [count:u32] [entry...]
;; Each entry: [type:u8] [len:u32] [data:bytes]
(func $constpool_entry (param $idx i32) (result i32)
;; Returns a heap-allocated string pointer for the constant at $idx.
;; Walks the constant pool to find the entry.
(local $pos i32) (local $count i32) (local $i i32)
(local $etype i32) (local $elen i32) (local $ptr i32)
(local.set $pos (' << ic(constpoolBase) << '))
(local.set $count (i32.load (local.get $pos)))
(local.set $pos (i32.add (local.get $pos) (i32.const 4)))
(local.set $i (i32.const 0))
(block $found
(loop $scan
(br_if $found (i32.ge_u (local.get $i) (local.get $count)))
(local.set $etype (i32.load8_u (local.get $pos)))
(local.set $pos (i32.add (local.get $pos) (i32.const 1)))
(local.set $elen (i32.load (local.get $pos)))
(local.set $pos (i32.add (local.get $pos) (i32.const 4)))
(if (i32.eq (local.get $i) (local.get $idx))
(then
;; Allocate a heap string and copy data into it
(local.set $ptr (call $alloc_string (local.get $pos) (local.get $elen)))
(return (local.get $ptr))
)
)
(local.set $pos (i32.add (local.get $pos) (local.get $elen)))
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $scan)
)
)
;; Not found — return null (0)
(i32.const 0)
)
;; ---- Function table access ----
;; Table format: [count:u32] [entry...], each entry variable-length:
;; [offset:u32][arity:u16][localCount:u16][hasRestArg:u8]
;; [nameCount:u16] for each name: [len:u16][data]
;; We walk the table to find the entry at a given index.
(global $fntable_cache_idx (mut i32) (i32.const -1))
(global $fntable_cache_off (mut i32) (i32.const 0))
(global $fntable_cache_ar (mut i32) (i32.const 0))
(global $fntable_cache_lc (mut i32) (i32.const 0))
(func $fntable_seek (param $idx i32)
;; Walk the function table to entry $idx and cache its fields.
(local $pos i32) (local $count i32) (local $i i32)
(local $nc i32) (local $j i32) (local $nlen i32)
;; Quick check: already cached?
(if (i32.eq (global.get $fntable_cache_idx) (local.get $idx))
(then (return)))
(local.set $pos (' << ic(fntableBase) << '))
(local.set $count (i32.load (local.get $pos)))
(local.set $pos (i32.add (local.get $pos) (i32.const 4)))
(local.set $i (i32.const 0))
(block $done
(loop $scan
(br_if $done (i32.ge_u (local.get $i) (local.get $count)))
(if (i32.eq (local.get $i) (local.get $idx))
(then
(global.set $fntable_cache_idx (local.get $idx))
(global.set $fntable_cache_off (i32.load (local.get $pos)))
(global.set $fntable_cache_ar
(i32.load16_u (i32.add (local.get $pos) (i32.const 4))))
(global.set $fntable_cache_lc
(i32.load16_u (i32.add (local.get $pos) (i32.const 6))))
(return)
)
)
;; Skip fixed header: offset(4) + arity(2) + localCount(2) + hasRestArg(1) = 9
(local.set $pos (i32.add (local.get $pos) (i32.const 9)))
;; Skip local names: nameCount(2) then for each: len(2) + data
(local.set $nc (i32.load16_u (local.get $pos)))
(local.set $pos (i32.add (local.get $pos) (i32.const 2)))
(local.set $j (i32.const 0))
(block $names_done
(loop $names
(br_if $names_done (i32.ge_u (local.get $j) (local.get $nc)))
(local.set $nlen (i32.load16_u (local.get $pos)))
(local.set $pos (i32.add (local.get $pos)
(i32.add (i32.const 2) (local.get $nlen))))
(local.set $j (i32.add (local.get $j) (i32.const 1)))
(br $names)
)
)
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $scan)
)
)
)
(func $fntable_offset (param $idx i32) (result i32)
(call $fntable_seek (local.get $idx))
(global.get $fntable_cache_off)
)
(func $fntable_arity (param $idx i32) (result i32)
(call $fntable_seek (local.get $idx))
(global.get $fntable_cache_ar)
)
(func $fntable_locals (param $idx i32) (result i32)
(call $fntable_seek (local.get $idx))
(global.get $fntable_cache_lc)
)
;; ---- Call frame management ----
;; Frame layout on call stack:
;; [return_pc:i32][saved_sp:i32][locals_ptr:i32][local_count:i32]
;; Total frame header = 16 bytes. Locals are heap-allocated.
(func $push_frame (param $ret_pc i32) (param $saved_sp i32)
(param $locals_ptr i32) (param $local_count i32)
(i32.store (global.get $csp) (local.get $ret_pc))
(i32.store (i32.add (global.get $csp) (i32.const 4)) (local.get $saved_sp))
(i32.store (i32.add (global.get $csp) (i32.const 8)) (local.get $locals_ptr))
(i32.store (i32.add (global.get $csp) (i32.const 12)) (local.get $local_count))
(global.set $csp (i32.add (global.get $csp) (i32.const 16)))
)
(func $pop_frame
(global.set $csp (i32.sub (global.get $csp) (i32.const 16)))
)
(func $frame_ret_pc (result i32)
(i32.load (i32.sub (global.get $csp) (i32.const 16)))
)
(func $frame_saved_sp (result i32)
(i32.load (i32.sub (global.get $csp) (i32.const 12)))
)
(func $frame_locals_ptr (result i32)
(i32.load (i32.sub (global.get $csp) (i32.const 8)))
)
(func $frame_local_count (result i32)
(i32.load (i32.sub (global.get $csp) (i32.const 4)))
)
;; ---- Local variable access (within current frame) ----
;; Locals are 8-byte tagged values on the heap
;; locals_ptr[idx] = [type:i32][val:i32]
(func $get_local_type (param $idx i32) (result i32)
(i32.load (i32.add
(call $frame_locals_ptr)
(i32.mul (local.get $idx) (i32.const 8))))
)
(func $get_local_val (param $idx i32) (result i32)
(i32.load (i32.add
(i32.add (call $frame_locals_ptr) (i32.const 4))
(i32.mul (local.get $idx) (i32.const 8))))
)
(func $set_local (param $idx i32) (param $type i32) (param $val i32)
(local $base i32)
(local.set $base (i32.add
(call $frame_locals_ptr)
(i32.mul (local.get $idx) (i32.const 8))))
(i32.store (local.get $base) (local.get $type))
(i32.store (i32.add (local.get $base) (i32.const 4)) (local.get $val))
)
;; ---- Allocate locals block ----
(func $alloc_locals (param $count i32) (result i32)
(local $ptr i32) (local $size i32)
(local.set $size (i32.mul (local.get $count) (i32.const 8)))
(local.set $ptr (call $alloc (local.get $size)))
;; Zero-initialize (all nulls: type=0, val=0)
(call $memzero (local.get $ptr) (local.get $size))
(local.get $ptr)
)
(func $memzero (param $dst i32) (param $n i32)
(local $i i32)
(local.set $i (i32.const 0))
(block $done
(loop $zero
(br_if $done (i32.ge_u (local.get $i) (local.get $n)))
(i32.store8 (i32.add (local.get $dst) (local.get $i)) (i32.const 0))
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $zero)
)
)
)
;; ---- Heap list helpers ----
;; List format: [len:i32][cap:i32][items_ptr:i32]
;; Items: array of 8-byte tagged values
(func $alloc_list (param $count i32) (result i32)
(local $ptr i32) (local $items i32)
(local.set $items (call $alloc (i32.mul (local.get $count) (i32.const 8))))
(local.set $ptr (call $alloc (i32.const 12)))
(i32.store (local.get $ptr) (local.get $count))
(i32.store (i32.add (local.get $ptr) (i32.const 4)) (local.get $count))
(i32.store (i32.add (local.get $ptr) (i32.const 8)) (local.get $items))
(local.get $ptr)
)
(func $list_len (param $ptr i32) (result i32)
(i32.load (local.get $ptr))
)
(func $list_get_type (param $ptr i32) (param $idx i32) (result i32)
(local $items i32)
(local.set $items (i32.load (i32.add (local.get $ptr) (i32.const 8))))
(i32.load (i32.add (local.get $items) (i32.mul (local.get $idx) (i32.const 8))))
)
(func $list_get_val (param $ptr i32) (param $idx i32) (result i32)
(local $items i32)
(local.set $items (i32.load (i32.add (local.get $ptr) (i32.const 8))))
(i32.load (i32.add
(i32.add (local.get $items) (i32.const 4))
(i32.mul (local.get $idx) (i32.const 8))))
)
(func $list_set (param $ptr i32) (param $idx i32)
(param $type i32) (param $val i32)
(local $items i32) (local $base i32)
(local.set $items (i32.load (i32.add (local.get $ptr) (i32.const 8))))
(local.set $base (i32.add (local.get $items) (i32.mul (local.get $idx) (i32.const 8))))
(i32.store (local.get $base) (local.get $type))
(i32.store (i32.add (local.get $base) (i32.const 4)) (local.get $val))
)
;; ---- Heap object helpers ----
;; Object format: [count:i32][capacity:i32][entries_ptr:i32]
;; Each entry: [key_str_ptr:i32][val_type:i32][val_payload:i32] = 12 bytes
(func $alloc_object (param $cap i32) (result i32)
(local $ptr i32) (local $entries i32)
(local.set $entries (call $alloc (i32.mul (local.get $cap) (i32.const 12))))
(call $memzero (local.get $entries) (i32.mul (local.get $cap) (i32.const 12)))
(local.set $ptr (call $alloc (i32.const 12)))
(i32.store (local.get $ptr) (i32.const 0))
(i32.store (i32.add (local.get $ptr) (i32.const 4)) (local.get $cap))
(i32.store (i32.add (local.get $ptr) (i32.const 8)) (local.get $entries))
(local.get $ptr)
)
(func $object_count (param $ptr i32) (result i32)
(i32.load (local.get $ptr))
)
(func $object_set (param $obj i32) (param $key i32)
(param $vtype i32) (param $vval i32)
(local $count i32) (local $cap i32) (local $entries i32)
(local $i i32) (local $base i32) (local $ekey i32)
(local.set $count (i32.load (local.get $obj)))
(local.set $cap (i32.load (i32.add (local.get $obj) (i32.const 4))))
(local.set $entries (i32.load (i32.add (local.get $obj) (i32.const 8))))
;; Search for existing key
(local.set $i (i32.const 0))
(block $found
(loop $search
(br_if $found (i32.ge_u (local.get $i) (local.get $count)))
(local.set $base (i32.add (local.get $entries)
(i32.mul (local.get $i) (i32.const 12))))
(local.set $ekey (i32.load (local.get $base)))
(if (call $str_eq (local.get $ekey) (local.get $key))
(then
;; Update existing entry
(i32.store (i32.add (local.get $base) (i32.const 4)) (local.get $vtype))
(i32.store (i32.add (local.get $base) (i32.const 8)) (local.get $vval))
(return)
)
)
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $search)
)
)
;; Append new entry (simple, no resize for now)
(local.set $base (i32.add (local.get $entries)
(i32.mul (local.get $count) (i32.const 12))))
(i32.store (local.get $base) (local.get $key))
(i32.store (i32.add (local.get $base) (i32.const 4)) (local.get $vtype))
(i32.store (i32.add (local.get $base) (i32.const 8)) (local.get $vval))
(i32.store (local.get $obj) (i32.add (local.get $count) (i32.const 1)))
)
(func $object_get (param $obj i32) (param $key i32) (result i32)
;; Returns: type via result, val via $tmp_val global
;; Returns TAG_NULL (0) if key not found
(local $count i32) (local $entries i32)
(local $i i32) (local $base i32) (local $ekey i32)
(local.set $count (i32.load (local.get $obj)))
(local.set $entries (i32.load (i32.add (local.get $obj) (i32.const 8))))
(local.set $i (i32.const 0))
(block $done
(loop $search
(br_if $done (i32.ge_u (local.get $i) (local.get $count)))
(local.set $base (i32.add (local.get $entries)
(i32.mul (local.get $i) (i32.const 12))))
(local.set $ekey (i32.load (local.get $base)))
(if (call $str_eq (local.get $ekey) (local.get $key))
(then
(global.set $tmp_val
(i32.load (i32.add (local.get $base) (i32.const 8))))
(return (i32.load (i32.add (local.get $base) (i32.const 4))))
)
)
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $search)
)
)
;; Not found
(global.set $tmp_val (i32.const 0))
(i32.const 0)
)
;; ---- Closure helpers ----
;; Closure heap format: [fn_idx:i32][scope_csp:i32]
(func $alloc_closure (param $fn_idx i32) (param $scope_csp i32) (result i32)
(local $ptr i32)
(local.set $ptr (call $alloc (i32.const 8)))
(i32.store (local.get $ptr) (local.get $fn_idx))
(i32.store (i32.add (local.get $ptr) (i32.const 4)) (local.get $scope_csp))
(local.get $ptr)
)
(func $closure_fn_idx (param $ptr i32) (result i32)
(i32.load (local.get $ptr))
)
;; ---- Integer to string conversion ----
(func $int_to_string (param $val i32) (result i32)
(local $ptr i32) (local $pos i32) (local $n i32)
(local $neg i32) (local $digit i32) (local $start i32) (local $end i32)
(local $tmp i32)
;; Max 12 chars for i32 (-2147483648)
(local.set $ptr (call $alloc (i32.const 16)))
(local.set $start (i32.add (local.get $ptr) (i32.const 4)))
(local.set $pos (local.get $start))
(local.set $n (local.get $val))
(local.set $neg (i32.const 0))
(if (i32.lt_s (local.get $n) (i32.const 0))
(then
(local.set $neg (i32.const 1))
(local.set $n (i32.sub (i32.const 0) (local.get $n)))
)
)
(if (i32.eqz (local.get $n))
(then
(i32.store8 (local.get $pos) (i32.const 48))
(local.set $pos (i32.add (local.get $pos) (i32.const 1)))
)
(else
(block $digits_done
(loop $digits
(br_if $digits_done (i32.eqz (local.get $n)))
(local.set $digit (i32.rem_u (local.get $n) (i32.const 10)))
(i32.store8 (local.get $pos) (i32.add (local.get $digit) (i32.const 48)))
(local.set $pos (i32.add (local.get $pos) (i32.const 1)))
(local.set $n (i32.div_u (local.get $n) (i32.const 10)))
(br $digits)
)
)
(if (local.get $neg)
(then
(i32.store8 (local.get $pos) (i32.const 45))
(local.set $pos (i32.add (local.get $pos) (i32.const 1)))
)
)
;; Reverse the digits in place
(local.set $end (i32.sub (local.get $pos) (i32.const 1)))
(block $rev_done
(loop $rev
(br_if $rev_done (i32.ge_u (local.get $start) (local.get $end)))
(local.set $tmp (i32.load8_u (local.get $start)))
(i32.store8 (local.get $start) (i32.load8_u (local.get $end)))
(i32.store8 (local.get $end) (local.get $tmp))
(local.set $start (i32.add (local.get $start) (i32.const 1)))
(local.set $end (i32.sub (local.get $end) (i32.const 1)))
(br $rev)
)
)
)
)
;; Store length
(i32.store (local.get $ptr)
(i32.sub (local.get $pos) (i32.add (local.get $ptr) (i32.const 4))))
(local.get $ptr)
)
;; ---- Value equality ----
(func $val_eq (param $t1 i32) (param $v1 i32)
(param $t2 i32) (param $v2 i32) (result i32)
;; Oak empty (_) equals everything
(if (i32.or (i32.eq (local.get $t1) (i32.const 1))
(i32.eq (local.get $t2) (i32.const 1)))
(then (return (i32.const 1))))
;; Types must match for all other comparisons
(if (i32.ne (local.get $t1) (local.get $t2))
(then (return (i32.const 0))))
;; Same type — compare by type
(if (i32.or (i32.eq (local.get $t1) (i32.const 0)) ;; null = null
(i32.eq (local.get $t1) (i32.const 1))) ;; empty = empty
(then (return (i32.const 1))))
(if (i32.le_u (local.get $t1) (i32.const 4)) ;; int, float, bool: compare payload
(then (return (i32.eq (local.get $v1) (local.get $v2)))))
(if (i32.or (i32.eq (local.get $t1) (i32.const 5)) ;; string
(i32.eq (local.get $t1) (i32.const 6))) ;; atom
(then (return (call $str_eq (local.get $v1) (local.get $v2)))))
;; Lists & objects: reference equality for now
(i32.eq (local.get $v1) (local.get $v2))
)
;; ---- Static string constructors (for builtins) ----
(func $make_static_str (param $c0 i32) (param $c1 i32) (param $c2 i32)
(param $c3 i32) (param $c4 i32) (param $slen i32) (result i32)
(local $ptr i32)
(local.set $ptr (call $alloc (i32.add (local.get $slen) (i32.const 4))))
(i32.store (local.get $ptr) (local.get $slen))
(if (i32.gt_u (local.get $slen) (i32.const 0))
(then (i32.store8 (i32.add (local.get $ptr) (i32.const 4)) (local.get $c0))))
(if (i32.gt_u (local.get $slen) (i32.const 1))
(then (i32.store8 (i32.add (local.get $ptr) (i32.const 5)) (local.get $c1))))
(if (i32.gt_u (local.get $slen) (i32.const 2))
(then (i32.store8 (i32.add (local.get $ptr) (i32.const 6)) (local.get $c2))))
(if (i32.gt_u (local.get $slen) (i32.const 3))
(then (i32.store8 (i32.add (local.get $ptr) (i32.const 7)) (local.get $c3))))
(if (i32.gt_u (local.get $slen) (i32.const 4))
(then (i32.store8 (i32.add (local.get $ptr) (i32.const 8)) (local.get $c4))))
(local.get $ptr)
)
;; "true"
(func $make_static_str_true (result i32)
(call $make_static_str (i32.const 116)(i32.const 114)(i32.const 117)(i32.const 101)(i32.const 0)(i32.const 4)))
;; "false"
(func $make_static_str_false (result i32)
(call $make_static_str (i32.const 102)(i32.const 97)(i32.const 108)(i32.const 115)(i32.const 101)(i32.const 5)))
;; "?"
(func $make_static_str_qmark (result i32)
(call $make_static_str (i32.const 63)(i32.const 0)(i32.const 0)(i32.const 0)(i32.const 0)(i32.const 1)))
;; Type name string constructors
(func $make_type_name_null (result i32)
(call $make_static_str (i32.const 110)(i32.const 117)(i32.const 108)(i32.const 108)(i32.const 0)(i32.const 4)))
(func $make_type_name_empty (result i32)
(call $make_static_str (i32.const 101)(i32.const 109)(i32.const 112)(i32.const 116)(i32.const 121)(i32.const 5)))
(func $make_type_name_int (result i32)
(call $make_static_str (i32.const 105)(i32.const 110)(i32.const 116)(i32.const 0)(i32.const 0)(i32.const 3)))
(func $make_type_name_float (result i32)
(call $make_static_str (i32.const 102)(i32.const 108)(i32.const 111)(i32.const 97)(i32.const 116)(i32.const 5)))
(func $make_type_name_bool (result i32)
(call $make_static_str (i32.const 98)(i32.const 111)(i32.const 111)(i32.const 108)(i32.const 0)(i32.const 4)))
(func $make_type_name_string (result i32)
;; "string" = 6 chars, need extended version
(local $ptr i32)
(local.set $ptr (call $alloc (i32.const 10)))
(i32.store (local.get $ptr) (i32.const 6))
(i32.store8 (i32.add (local.get $ptr)(i32.const 4))(i32.const 115))
(i32.store8 (i32.add (local.get $ptr)(i32.const 5))(i32.const 116))
(i32.store8 (i32.add (local.get $ptr)(i32.const 6))(i32.const 114))
(i32.store8 (i32.add (local.get $ptr)(i32.const 7))(i32.const 105))
(i32.store8 (i32.add (local.get $ptr)(i32.const 8))(i32.const 110))
(i32.store8 (i32.add (local.get $ptr)(i32.const 9))(i32.const 103))
(local.get $ptr))
(func $make_type_name_atom (result i32)
(call $make_static_str (i32.const 97)(i32.const 116)(i32.const 111)(i32.const 109)(i32.const 0)(i32.const 4)))
(func $make_type_name_list (result i32)
(call $make_static_str (i32.const 108)(i32.const 105)(i32.const 115)(i32.const 116)(i32.const 0)(i32.const 4)))
(func $make_type_name_object (result i32)
;; "object" = 6 chars
(local $ptr i32)
(local.set $ptr (call $alloc (i32.const 10)))
(i32.store (local.get $ptr) (i32.const 6))
(i32.store8 (i32.add (local.get $ptr)(i32.const 4))(i32.const 111))
(i32.store8 (i32.add (local.get $ptr)(i32.const 5))(i32.const 98))
(i32.store8 (i32.add (local.get $ptr)(i32.const 6))(i32.const 106))
(i32.store8 (i32.add (local.get $ptr)(i32.const 7))(i32.const 101))
(i32.store8 (i32.add (local.get $ptr)(i32.const 8))(i32.const 99))
(i32.store8 (i32.add (local.get $ptr)(i32.const 9))(i32.const 116))
(local.get $ptr))
(func $make_type_name_function (result i32)
;; "function" = 8 chars
(local $ptr i32)
(local.set $ptr (call $alloc (i32.const 12)))
(i32.store (local.get $ptr) (i32.const 8))
(i32.store8 (i32.add (local.get $ptr)(i32.const 4))(i32.const 102))
(i32.store8 (i32.add (local.get $ptr)(i32.const 5))(i32.const 117))
(i32.store8 (i32.add (local.get $ptr)(i32.const 6))(i32.const 110))
(i32.store8 (i32.add (local.get $ptr)(i32.const 7))(i32.const 99))
(i32.store8 (i32.add (local.get $ptr)(i32.const 8))(i32.const 116))
(i32.store8 (i32.add (local.get $ptr)(i32.const 9))(i32.const 105))
(i32.store8 (i32.add (local.get $ptr)(i32.const 10))(i32.const 111))
(i32.store8 (i32.add (local.get $ptr)(i32.const 11))(i32.const 110))
(local.get $ptr))
;; ---- Object keys/values helpers ----
(func $object_keys_list (param $obj i32) (result i32)
(local $count i32) (local $entries i32) (local $lst i32)
(local $i i32) (local $base i32)
(local.set $count (i32.load (local.get $obj)))
(local.set $entries (i32.load (i32.add (local.get $obj) (i32.const 8))))
(local.set $lst (call $alloc_list (local.get $count)))
(local.set $i (i32.const 0))
(block $done
(loop $iter
(br_if $done (i32.ge_u (local.get $i) (local.get $count)))
(local.set $base (i32.add (local.get $entries)
(i32.mul (local.get $i) (i32.const 12))))
;; Key is a string pointer at base+0
(call $list_set (local.get $lst) (local.get $i)
(i32.const 5) (i32.load (local.get $base)))
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $iter)
)
)
(local.get $lst)
)
(func $object_values_list (param $obj i32) (result i32)
(local $count i32) (local $entries i32) (local $lst i32)
(local $i i32) (local $base i32)
(local.set $count (i32.load (local.get $obj)))
(local.set $entries (i32.load (i32.add (local.get $obj) (i32.const 8))))
(local.set $lst (call $alloc_list (local.get $count)))
(local.set $i (i32.const 0))
(block $done
(loop $iter
(br_if $done (i32.ge_u (local.get $i) (local.get $count)))
(local.set $base (i32.add (local.get $entries)
(i32.mul (local.get $i) (i32.const 12))))
;; Value type at base+4, value payload at base+8
(call $list_set (local.get $lst) (local.get $i)
(i32.load (i32.add (local.get $base) (i32.const 4)))
(i32.load (i32.add (local.get $base) (i32.const 8))))
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $iter)
)
)
(local.get $lst)
)
;; ---- String slice ----
(func $string_slice (param $s i32) (param $start i32) (param $end i32) (result i32)
(local $slen i32) (local $slice_len i32)
(local.set $slen (call $string_len (local.get $s)))
;; Clamp bounds
(if (i32.lt_s (local.get $start) (i32.const 0))
(then (local.set $start (i32.const 0))))
(if (i32.gt_s (local.get $end) (local.get $slen))
(then (local.set $end (local.get $slen))))
(if (i32.gt_s (local.get $start) (local.get $end))
(then (local.set $start (local.get $end))))
(local.set $slice_len (i32.sub (local.get $end) (local.get $start)))
(call $alloc_string
(i32.add (call $string_data (local.get $s)) (local.get $start))
(local.get $slice_len))
)
;; ---- List slice ----
(func $list_slice (param $lst i32) (param $start i32) (param $end i32) (result i32)
(local $llen i32) (local $new_lst i32) (local $slice_len i32)
(local $i i32) (local $items i32) (local $base i32)
(local.set $llen (call $list_len (local.get $lst)))
;; Clamp bounds
(if (i32.lt_s (local.get $start) (i32.const 0))
(then (local.set $start (i32.const 0))))
(if (i32.gt_s (local.get $end) (local.get $llen))
(then (local.set $end (local.get $llen))))
(if (i32.gt_s (local.get $start) (local.get $end))
(then (local.set $start (local.get $end))))
(local.set $slice_len (i32.sub (local.get $end) (local.get $start)))
(local.set $new_lst (call $alloc_list (local.get $slice_len)))
(local.set $items (i32.load (i32.add (local.get $lst) (i32.const 8))))
(local.set $i (i32.const 0))
(block $done
(loop $copy
(br_if $done (i32.ge_u (local.get $i) (local.get $slice_len)))
(local.set $base (i32.add (local.get $items)
(i32.mul (i32.add (local.get $start) (local.get $i)) (i32.const 8))))
(call $list_set (local.get $new_lst) (local.get $i)
(i32.load (local.get $base))
(i32.load (i32.add (local.get $base) (i32.const 4))))
(local.set $i (i32.add (local.get $i) (i32.const 1)))
(br $copy)
)
)
(local.get $new_lst)
)
;; ---- List append (non-mutating, returns new list) ----
(func $list_append (param $lst i32) (param $vtype i32) (param $vval i32) (result i32)
(local $llen i32) (local $new_lst i32) (local $items i32)
(local $new_items i32) (local $i i32) (local $base i32)
(local.set $llen (call $list_len (local.get $lst)))
(local.set $new_lst (call $alloc_list (i32.add (local.get $llen) (i32.const 1))))
(local.set $items (i32.load (i32.add (local.get $lst) (i32.const 8))))
(local.set $new_items (i32.load (i32.add (local.get $new_lst) (i32.const 8))))
;; Copy existing elements
(call $memcpy (local.get $new_items) (local.get $items)
(i32.mul (local.get $llen) (i32.const 8)))
;; Append new element
(call $list_set (local.get $new_lst) (local.get $llen)
(local.get $vtype) (local.get $vval))
(local.get $new_lst)
)
;; ===================================================================
;; ---- VM DISPATCH LOOP ----
;; ===================================================================
(func $vm_run (export "run")
(local $op i32)
(local $t1 i32) (local $v1 i32)
(local $t2 i32) (local $v2 i32)
(local $idx i32) (local $tmp i32) (local $tmp2 i32)
(local $fn_idx i32) (local $arity i32) (local $expected i32)
(local $locals_ptr i32) (local $i i32)
(local $key_ptr i32) (local $obj_ptr i32) (local $list_ptr i32)
(local $ret_type i32) (local $ret_val i32)
;; Push an initial frame for the top-level program
(call $push_frame
(i32.const 0) ;; no return address
(global.get $sp) ;; saved sp
(call $alloc_locals (i32.const 256)) ;; generous top-level locals
(i32.const 256))
(block $halt
(loop $dispatch
;; ---- Fetch opcode ----
(local.set $op (call $fetch_u8))
;; ---- Dispatch via nested blocks + br_table ----
' << generateDispatchTable() << '
(br $dispatch)
) ;; end loop
) ;; end halt block
) ;; end $vm_run
;; ---- Built-in function dispatcher ----
(func $call_builtin (param $bi i32) (param $arity i32)
(local $t1 i32) (local $v1 i32)
(local $t2 i32) (local $v2 i32)
(local $t3 i32) (local $v3 i32)
(local $tmp i32) (local $i i32)
;; Dispatch by builtin index
(if (i32.eqz (local.get $bi))
(then
;; BUILTIN_PRINT (0): print(value)
(local.set $t1 (call $pop_tagged))
(local.set $v1 (global.get $tmp_val))
(if (i32.eq (local.get $t1) (i32.const 5)) ;; TAG_STRING
(then
(call $host_print
(call $string_data (local.get $v1))
(call $string_len (local.get $v1)))
)
(else
;; Convert to string first
(if (i32.eq (local.get $t1) (i32.const 2)) ;; TAG_INT
(then
(local.set $v1 (call $int_to_string (local.get $v1)))
(call $host_print
(call $string_data (local.get $v1))
(call $string_len (local.get $v1)))
)
(else
(if (i32.eq (local.get $t1) (i32.const 4)) ;; TAG_BOOL