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594 lines
14 KiB
V
594 lines
14 KiB
V
// compiler.v — bytecode code generator for VuurRaaf.
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//
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// Compiles a parsed program into a VROBJ object file: flat bytecode plus a
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// symbol per function and a relocation per call site. Call targets are left as
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// relocations and resolved by the linker, so functions may live in other files.
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module compiler
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import os
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import obj
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// opcodes — keep in sync with vm/vm.v and assembler/assembler.v
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const op_halt = u8(0)
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const op_push_i = u8(1)
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const op_push_s = u8(2)
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const op_load = u8(3)
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const op_store = u8(4)
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const op_pop = u8(5)
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const op_dup = u8(6)
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const op_add = u8(7)
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const op_sub = u8(8)
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const op_mul = u8(9)
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const op_div = u8(10)
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const op_mod = u8(11)
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const op_neg = u8(12)
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const op_eq = u8(13)
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const op_ne = u8(14)
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const op_lt = u8(15)
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const op_le = u8(16)
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const op_gt = u8(17)
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const op_ge = u8(18)
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const op_and = u8(19)
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const op_or = u8(20)
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const op_not = u8(21)
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const op_jmp = u8(22)
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const op_jz = u8(23)
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const op_jnz = u8(24)
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const op_call = u8(25)
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const op_ret = u8(26)
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const op_retv = u8(27)
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const op_print = u8(28)
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const op_println = u8(29)
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const op_assert = u8(30)
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const op_enter = u8(31)
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const op_mkarray = u8(32)
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const op_aget = u8(33)
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const op_aset = u8(34)
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const op_alen = u8(35)
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const op_apush = u8(36)
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const op_mkstruct = u8(37)
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const op_sget = u8(38)
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const op_sset = u8(39)
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// compile parses and compiles VuurRaaf source into an object file.
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pub fn compile(src string) !obj.Obj {
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toks := tokenize(src)!
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prog := parse(toks)!
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return gen(prog)
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}
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pub fn compile_file(path string) !obj.Obj {
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src := os.read_file(path)!
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return compile(src)!
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}
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// ---------------------------------------------------------------------------
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struct Fixup {
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name string
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off u32
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}
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// LoopCtx records where `break` and `continue` should jump while generating
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// the body of a loop. For `for` loops `continue` targets the increment, not
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// the condition check, so the loop variable still advances.
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struct LoopCtx {
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break_l string
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continue_l string
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}
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struct Gen {
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mut:
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code []u8
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strings []string
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str_map map[string]int
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symbols []obj.Symbol
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relocs []obj.Reloc
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locals map[string]int
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local_cnt int
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argc int
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cur_fn string
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labels map[string]int
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fixups []Fixup
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loops []LoopCtx
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enter_off u32
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next_lbl int
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}
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fn gen(prog Program) !obj.Obj {
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mut g := Gen{}
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for fd in prog.fns {
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g.gen_fn(fd)!
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}
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return obj.Obj{
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symbols: g.symbols
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strings: g.strings
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code: g.code
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relocs: g.relocs
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}
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}
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fn (mut g Gen) gen_fn(fd FnDecl) ! {
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g.cur_fn = fd.name
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g.symbols << obj.Symbol{ name: fd.name, entry: g.code.len }
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g.locals.clear()
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g.local_cnt = 0
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g.argc = fd.params.len
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for i, p in fd.params {
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g.locals[p] = i
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}
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g.local_cnt = g.argc
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// `enter n` reserves the non-parameter locals; n is patched once the body
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// has been scanned.
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g.code << op_enter
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g.enter_off = u32(g.code.len)
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g.code << obj.encode_i64(0)
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for st in fd.body {
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g.gen_stmt(st)!
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}
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g.code << op_ret // trailing return for fall-through
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obj.patch_i64(mut g.code, g.enter_off, i64(g.local_cnt - g.argc))
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// resolve intra-function jump targets
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for f in g.fixups {
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target := g.labels[f.name] or {
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return error('internal error: unresolved label ${f.name} in fn ${fd.name}')
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}
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obj.patch_i64(mut g.code, f.off, i64(target))
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}
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g.fixups.clear()
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g.labels.clear()
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g.cur_fn = ''
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}
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fn (mut g Gen) gen_stmt(st Stmt) ! {
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match st.kind {
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.expr_stmt {
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g.gen_expr(st.expr)!
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// print/println already consume their value; everything else
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// leaves one on the stack that must be discarded
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if st.expr.kind == .call && (st.expr.name == 'print' || st.expr.name == 'println') {
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// nothing to discard
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} else {
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g.code << op_pop
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}
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}
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.let_stmt {
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g.gen_expr(st.expr)!
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idx := g.local_cnt
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g.local_cnt++
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g.locals[st.target] = idx
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g.code << op_store
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g.code << obj.encode_i64(i64(idx))
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}
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.assign_stmt {
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idx := g.locals[st.target] or {
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return error('unknown variable "${st.target}" at line ${st.line}')
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}
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g.gen_expr(st.expr)!
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g.code << op_store
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g.code << obj.encode_i64(i64(idx))
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}
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.index_assign {
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g.gen_expr(st.base)!
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g.gen_expr(st.idx)!
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g.gen_expr(st.expr)!
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g.code << op_aset
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}
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.field_assign {
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// a.b = v → a, v, "b" sset (field name on top of the stack)
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g.gen_expr(st.base)!
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g.gen_expr(st.expr)!
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g.emit_field_name(st.target)
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g.code << op_sset
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}
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.if_stmt {
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else_l := g.new_label()
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end_l := g.new_label()
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g.gen_expr(st.cond)!
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g.code << op_jz
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: else_l, off: u32(g.code.len) - 8 }
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for s in st.body {
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g.gen_stmt(s)!
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}
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g.code << op_jmp
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
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g.emit_label(else_l)
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for s in st.els {
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g.gen_stmt(s)!
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}
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g.emit_label(end_l)
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}
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.match_stmt {
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// match x { v1 {..} v2 {..} else {..} } → subject := x; a chain of
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// equality tests jumping to the matching arm; else falls through.
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subj_idx := g.new_local()
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end_l := g.new_label()
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g.gen_expr(st.expr)!
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g.emit_store(subj_idx)
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for i, arm in st.arms {
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next_l := g.new_label()
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g.emit_load(subj_idx)
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g.gen_expr(arm.val)!
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g.code << op_eq
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g.code << op_jz
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: next_l, off: u32(g.code.len) - 8 }
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for s in arm.body {
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g.gen_stmt(s)!
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}
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g.code << op_jmp
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
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g.emit_label(next_l)
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if i == st.arms.len - 1 && !st.has_else {
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// no else: fall through to the end label
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g.emit_label(end_l)
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}
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}
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if st.has_else {
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for s in st.els_body {
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g.gen_stmt(s)!
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}
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g.emit_label(end_l)
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}
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}
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.while_stmt {
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loop_l := g.new_label()
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end_l := g.new_label()
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g.emit_label(loop_l)
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g.gen_expr(st.cond)!
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g.code << op_jz
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
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g.loops << LoopCtx{ break_l: end_l, continue_l: loop_l }
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for s in st.body {
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g.gen_stmt(s)!
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}
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g.loops.delete_last()
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g.code << op_jmp
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: loop_l, off: u32(g.code.len) - 8 }
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g.emit_label(end_l)
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}
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.for_range_stmt {
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// for i in a..b / for i in a...b → i := a; while i <(<=) b { body; i++ }
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var_idx := g.new_local()
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bound_idx := g.new_local()
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loop_l := g.new_label()
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inc_l := g.new_label()
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end_l := g.new_label()
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g.gen_expr(st.expr)!
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g.gen_expr(st.cond)!
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g.emit_store(bound_idx)
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g.emit_store(var_idx)
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g.emit_label(loop_l)
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g.emit_load(var_idx)
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g.emit_load(bound_idx)
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g.code << if st.inclusive { op_le } else { op_lt }
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g.code << op_jz
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
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g.loops << LoopCtx{ break_l: end_l, continue_l: inc_l }
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prev := g.locals[st.target] or { -1 }
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g.locals[st.target] = var_idx
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for s in st.body {
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g.gen_stmt(s)!
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}
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if prev >= 0 {
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g.locals[st.target] = prev
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} else {
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g.locals.delete(st.target)
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}
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g.loops.delete_last()
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g.emit_label(inc_l)
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g.emit_load(var_idx)
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g.code << op_push_i
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g.code << obj.encode_i64(1)
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g.code << op_add
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g.emit_store(var_idx)
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g.code << op_jmp
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: loop_l, off: u32(g.code.len) - 8 }
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g.emit_label(end_l)
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}
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.for_in_stmt {
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// for x in arr → idx := 0; while idx < len(arr) { x := arr[idx]; body; idx++ }
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arr_idx := g.new_local()
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idx_idx := g.new_local()
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elem_idx := g.new_local()
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loop_l := g.new_label()
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inc_l := g.new_label()
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end_l := g.new_label()
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g.gen_expr(st.expr)!
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g.emit_store(arr_idx)
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g.code << op_push_i
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g.code << obj.encode_i64(0)
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g.emit_store(idx_idx)
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g.emit_label(loop_l)
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g.emit_load(idx_idx)
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g.emit_load(arr_idx)
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g.code << op_alen
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g.code << op_lt
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g.code << op_jz
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
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g.loops << LoopCtx{ break_l: end_l, continue_l: inc_l }
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g.emit_load(arr_idx)
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g.emit_load(idx_idx)
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g.code << op_aget
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g.emit_store(elem_idx)
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prev := g.locals[st.target] or { -1 }
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g.locals[st.target] = elem_idx
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for s in st.body {
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g.gen_stmt(s)!
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}
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if prev >= 0 {
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g.locals[st.target] = prev
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} else {
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g.locals.delete(st.target)
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}
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g.loops.delete_last()
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g.emit_label(inc_l)
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g.emit_load(idx_idx)
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g.code << op_push_i
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g.code << obj.encode_i64(1)
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g.code << op_add
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g.emit_store(idx_idx)
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g.code << op_jmp
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: loop_l, off: u32(g.code.len) - 8 }
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g.emit_label(end_l)
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}
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.ret_stmt {
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if st.has_val {
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g.gen_expr(st.expr)!
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g.code << op_retv
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} else {
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g.code << op_ret
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}
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}
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.assert_stmt {
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g.gen_expr(st.expr)!
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g.code << op_assert
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}
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.break_stmt {
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if g.loops.len == 0 {
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return error('break outside of a loop (line ${st.line})')
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}
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ctx := g.loops[g.loops.len - 1]
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g.code << op_jmp
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: ctx.break_l, off: u32(g.code.len) - 8 }
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}
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.continue_stmt {
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if g.loops.len == 0 {
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return error('continue outside of a loop (line ${st.line})')
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}
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ctx := g.loops[g.loops.len - 1]
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g.code << op_jmp
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g.code << obj.encode_i64(0)
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g.fixups << Fixup{ name: ctx.continue_l, off: u32(g.code.len) - 8 }
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}
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}
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}
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fn (mut g Gen) gen_expr(e Expr) ! {
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match e.kind {
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.int_lit {
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g.code << op_push_i
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g.code << obj.encode_i64(e.int_v)
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}
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.str_lit {
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// the index is a placeholder; the linker rebases it via a string
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// relocation so multi-file links keep working
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g.code << op_push_s
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g.code << obj.encode_i64(0)
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g.relocs << obj.Reloc{ offset: u32(g.code.len) - 8, name: e.str_v, kind: 1 }
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}
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.array_lit {
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for el in e.elems {
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g.gen_expr(el)!
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}
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g.code << op_mkarray
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g.code << obj.encode_i64(i64(e.elems.len))
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}
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.struct_lit {
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// for each field: push the name string then the value; mkstruct n
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// pops the (name, value) pairs and builds the record
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for f in e.fields {
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g.emit_field_name(f.name)
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g.gen_expr(f.val)!
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}
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g.code << op_mkstruct
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g.code << obj.encode_i64(i64(e.fields.len))
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}
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.field {
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g.gen_expr(*e.left)!
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g.emit_field_name(e.name)
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g.code << op_sget
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}
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.index {
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g.gen_expr(*e.left)!
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g.gen_expr(*e.right)!
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g.code << op_aget
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}
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.bool_lit {
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g.code << op_push_i
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g.code << obj.encode_i64(e.int_v)
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}
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.ident {
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idx := g.locals[e.name] or {
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return error('unknown variable "${e.name}" at line ${e.line}')
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}
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g.code << op_load
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g.code << obj.encode_i64(i64(idx))
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}
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.unary {
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g.gen_expr(*e.right)!
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if e.op == .kw_not {
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g.code << op_not
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} else {
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g.code << op_neg
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}
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}
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.binary {
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g.gen_binary(e)!
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}
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.call {
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g.gen_call(e)!
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}
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}
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}
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fn (mut g Gen) gen_call(e Expr) ! {
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if e.name == 'print' || e.name == 'println' {
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if e.args.len != 1 {
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return error('${e.name}() takes exactly one argument (line ${e.line})')
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}
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g.gen_expr(e.args[0])!
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g.code << if e.name == 'print' { op_print } else { op_println }
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return
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}
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if e.name == 'len' {
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if e.args.len != 1 {
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return error('len() takes exactly one argument (line ${e.line})')
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}
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g.gen_expr(e.args[0])!
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g.code << op_alen
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return
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}
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if e.name == 'push' {
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if e.args.len != 2 {
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return error('push() takes exactly two arguments (line ${e.line})')
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}
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g.gen_expr(e.args[0])!
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g.gen_expr(e.args[1])!
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g.code << op_apush
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return
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}
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for a in e.args {
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g.gen_expr(a)!
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}
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g.code << op_call
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g.code << obj.encode_i64(0) // placeholder — patched by the linker
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g.relocs << obj.Reloc{ offset: u32(g.code.len) - 8, name: e.name, kind: 0 }
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g.code << obj.encode_i64(i64(e.args.len)) // argc
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}
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fn (mut g Gen) gen_binary(e Expr) ! {
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match e.op {
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.kw_and {
|
|
// a and b → short-circuit: if !a or !b then 0 else 1
|
|
false_l := g.new_label()
|
|
end_l := g.new_label()
|
|
g.gen_expr(*e.left)!
|
|
g.code << op_jz
|
|
g.code << obj.encode_i64(0)
|
|
g.fixups << Fixup{ name: false_l, off: u32(g.code.len) - 8 }
|
|
g.gen_expr(*e.right)!
|
|
g.code << op_jz
|
|
g.code << obj.encode_i64(0)
|
|
g.fixups << Fixup{ name: false_l, off: u32(g.code.len) - 8 }
|
|
g.code << op_push_i
|
|
g.code << obj.encode_i64(1)
|
|
g.code << op_jmp
|
|
g.code << obj.encode_i64(0)
|
|
g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
|
|
g.emit_label(false_l)
|
|
g.code << op_push_i
|
|
g.code << obj.encode_i64(0)
|
|
g.emit_label(end_l)
|
|
}
|
|
.kw_or {
|
|
// a or b → short-circuit: if a or b then 1 else 0
|
|
true_l := g.new_label()
|
|
end_l := g.new_label()
|
|
g.gen_expr(*e.left)!
|
|
g.code << op_jnz
|
|
g.code << obj.encode_i64(0)
|
|
g.fixups << Fixup{ name: true_l, off: u32(g.code.len) - 8 }
|
|
g.gen_expr(*e.right)!
|
|
g.code << op_jnz
|
|
g.code << obj.encode_i64(0)
|
|
g.fixups << Fixup{ name: true_l, off: u32(g.code.len) - 8 }
|
|
g.code << op_push_i
|
|
g.code << obj.encode_i64(0)
|
|
g.code << op_jmp
|
|
g.code << obj.encode_i64(0)
|
|
g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
|
|
g.emit_label(true_l)
|
|
g.code << op_push_i
|
|
g.code << obj.encode_i64(1)
|
|
g.emit_label(end_l)
|
|
}
|
|
else {
|
|
g.gen_expr(*e.left)!
|
|
g.gen_expr(*e.right)!
|
|
op := match e.op {
|
|
.plus { op_add }
|
|
.minus { op_sub }
|
|
.star { op_mul }
|
|
.slash { op_div }
|
|
.percent { op_mod }
|
|
.eq_eq { op_eq }
|
|
.not_eq { op_ne }
|
|
.lt { op_lt }
|
|
.le { op_le }
|
|
.gt { op_gt }
|
|
.ge { op_ge }
|
|
else {
|
|
return error('unsupported binary operator at line ${e.line}')
|
|
}
|
|
}
|
|
g.code << op
|
|
}
|
|
}
|
|
}
|
|
|
|
// emit_field_name pushes a field name as a string constant. Like string
|
|
// literals it goes through a kind-1 relocation so multi-file links rebase it.
|
|
fn (mut g Gen) emit_field_name(name string) {
|
|
g.code << op_push_s
|
|
g.code << obj.encode_i64(0)
|
|
g.relocs << obj.Reloc{ offset: u32(g.code.len) - 8, name: name, kind: 1 }
|
|
}
|
|
|
|
fn (mut g Gen) intern(s string) int {
|
|
if s in g.str_map {
|
|
return g.str_map[s]
|
|
}
|
|
idx := g.strings.len
|
|
g.strings << s
|
|
g.str_map[s] = idx
|
|
return idx
|
|
}
|
|
|
|
fn (mut g Gen) new_local() int {
|
|
idx := g.local_cnt
|
|
g.local_cnt++
|
|
return idx
|
|
}
|
|
|
|
fn (mut g Gen) emit_load(idx int) {
|
|
g.code << op_load
|
|
g.code << obj.encode_i64(i64(idx))
|
|
}
|
|
|
|
fn (mut g Gen) emit_store(idx int) {
|
|
g.code << op_store
|
|
g.code << obj.encode_i64(i64(idx))
|
|
}
|
|
|
|
|
|
|
|
fn (mut g Gen) new_label() string {
|
|
g.next_lbl++
|
|
return 'L${g.next_lbl}'
|
|
}
|
|
|
|
fn (mut g Gen) emit_label(name string) {
|
|
g.labels[name] = g.code.len
|
|
}
|