Files
bear/compiler/compiler.v
T

733 lines
19 KiB
V

// compiler.v — bytecode code generator for VuurRaaf.
//
// Compiles a parsed program into a VROBJ object file: flat bytecode plus a
// symbol per function and a relocation per call site. Call targets are left as
// relocations and resolved by the linker, so functions may live in other files.
module compiler
import os
import obj
// opcodes — keep in sync with vm/vm.v and assembler/assembler.v
const op_halt = u8(0)
const op_push_i = u8(1)
const op_push_s = u8(2)
const op_load = u8(3)
const op_store = u8(4)
const op_pop = u8(5)
const op_dup = u8(6)
const op_add = u8(7)
const op_sub = u8(8)
const op_mul = u8(9)
const op_div = u8(10)
const op_mod = u8(11)
const op_neg = u8(12)
const op_eq = u8(13)
const op_ne = u8(14)
const op_lt = u8(15)
const op_le = u8(16)
const op_gt = u8(17)
const op_ge = u8(18)
const op_and = u8(19)
const op_or = u8(20)
const op_not = u8(21)
const op_jmp = u8(22)
const op_jz = u8(23)
const op_jnz = u8(24)
const op_call = u8(25)
const op_ret = u8(26)
const op_retv = u8(27)
const op_print = u8(28)
const op_println = u8(29)
const op_assert = u8(30)
const op_enter = u8(31)
const op_mkarray = u8(32)
const op_aget = u8(33)
const op_aset = u8(34)
const op_alen = u8(35)
const op_apush = u8(36)
const op_mkstruct = u8(37)
const op_sget = u8(38)
const op_sset = u8(39)
// compile parses and compiles VuurRaaf source into an object file.
pub fn compile(src string) !obj.Obj {
toks := tokenize(src)!
prog := parse(toks)!
return gen(prog)
}
pub fn compile_file(path string) !obj.Obj {
src := os.read_file(path)!
return compile(src)!
}
// ---------------------------------------------------------------------------
struct Fixup {
name string
off u32
}
// LoopCtx records where `break` and `continue` should jump while generating
// the body of a loop. For `for` loops `continue` targets the increment, not
// the condition check, so the loop variable still advances.
struct LoopCtx {
break_l string
continue_l string
}
struct Gen {
mut:
code []u8
strings []string
str_map map[string]int
symbols []obj.Symbol
relocs []obj.Reloc
locals map[string]int
types map[string]string // local name -> declared struct type ('' = unknown)
structs map[string][]string // declared struct name -> field list
enums map[string][]string // enum name -> variant list
enum_vals map[string]int // 'Enum.variant' -> integer value
local_cnt int
argc int
cur_fn string
labels map[string]int
fixups []Fixup
loops []LoopCtx
enter_off u32
next_lbl int
}
fn gen(prog Program) !obj.Obj {
mut g := Gen{}
// register enums first so their values are available everywhere
for ed in prog.enums {
if ed.name in g.enums {
return error('duplicate enum declaration "${ed.name}"')
}
g.enums[ed.name] = ed.variants
for i, v in ed.variants {
g.enum_vals['${ed.name}.${v}'] = i
}
}
// register struct declarations
for sd in prog.structs {
if sd.name in g.structs {
return error('duplicate struct declaration "${sd.name}"')
}
g.structs[sd.name] = sd.fields
}
// compile imported files and merge their objects
for imp in prog.imports {
imported := compile_file(imp.path)!
// merge symbols from the imported object
for s in imported.symbols {
g.symbols << s
}
// merge strings
for s in imported.strings {
g.strings << s
}
// append imported bytecode and adjust relocations
code_off := g.code.len
g.code << imported.code
for r in imported.relocs {
g.relocs << obj.Reloc{ offset: u32(code_off) + r.offset, name: r.name, kind: r.kind }
}
}
for fd in prog.fns {
g.gen_fn(fd)!
}
return obj.Obj{
symbols: g.symbols
strings: g.strings
code: g.code
relocs: g.relocs
}
}
fn (mut g Gen) gen_fn(fd FnDecl) ! {
// methods compile to functions named `Type.method`; the receiver is the
// implicit first argument, so `p.dist(x)` becomes `call Point.dist p, x`
sym := if fd.recv_type.len > 0 { '${fd.recv_type}.${fd.name}' } else { fd.name }
g.cur_fn = sym
g.symbols << obj.Symbol{ name: sym, entry: g.code.len }
g.locals.clear()
g.types.clear()
g.local_cnt = 0
g.argc = fd.params.len + if fd.recv_type.len > 0 { 1 } else { 0 }
mut next := 0
if fd.recv_type.len > 0 {
g.locals[fd.recv_name] = 0
g.types[fd.recv_name] = fd.recv_type
next = 1
}
for i, p in fd.params {
g.locals[p] = i + next
}
g.local_cnt = g.argc
// `enter n` reserves the non-parameter locals; n is patched once the body
// has been scanned.
g.code << op_enter
g.enter_off = u32(g.code.len)
g.code << obj.encode_i64(0)
for st in fd.body {
g.gen_stmt(st)!
}
g.code << op_ret // trailing return for fall-through
obj.patch_i64(mut g.code, g.enter_off, i64(g.local_cnt - g.argc))
// resolve intra-function jump targets
for f in g.fixups {
target := g.labels[f.name] or {
return error('internal error: unresolved label ${f.name} in fn ${fd.name}')
}
obj.patch_i64(mut g.code, f.off, i64(target))
}
g.fixups.clear()
g.labels.clear()
g.cur_fn = ''
}
fn (mut g Gen) gen_stmt(st Stmt) ! {
match st.kind {
.expr_stmt {
g.gen_expr(st.expr)!
// print/println already consume their value; everything else
// leaves one on the stack that must be discarded
if st.expr.kind == .call && (st.expr.name == 'print' || st.expr.name == 'println') {
// nothing to discard
} else {
g.code << op_pop
}
}
.let_stmt {
g.gen_expr(st.expr)!
idx := g.local_cnt
g.local_cnt++
g.locals[st.target] = idx
g.types[st.target] = g.expr_type(st.expr)
g.code << op_store
g.code << obj.encode_i64(i64(idx))
}
.assign_stmt {
idx := g.locals[st.target] or {
return error('unknown variable "${st.target}" at line ${st.line}')
}
g.gen_expr(st.expr)!
g.types[st.target] = g.expr_type(st.expr)
g.code << op_store
g.code << obj.encode_i64(i64(idx))
}
.index_assign {
g.gen_expr(st.base)!
g.gen_expr(st.idx)!
g.gen_expr(st.expr)!
g.code << op_aset
}
.field_assign {
// a.b = v → a, v, "b" sset (field name on top of the stack)
g.gen_expr(st.base)!
g.gen_expr(st.expr)!
g.emit_field_name(st.target)
g.code << op_sset
}
.if_stmt {
else_l := g.new_label()
end_l := g.new_label()
g.gen_expr(st.cond)!
g.code << op_jz
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: else_l, off: u32(g.code.len) - 8 }
for s in st.body {
g.gen_stmt(s)!
}
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(else_l)
for s in st.els {
g.gen_stmt(s)!
}
g.emit_label(end_l)
}
.match_stmt {
// match x { v1 {..} v2 {..} else {..} } → subject := x; a chain of
// equality tests jumping to the matching arm; else falls through.
subj_idx := g.new_local()
end_l := g.new_label()
g.gen_expr(st.expr)!
g.emit_store(subj_idx)
for i, arm in st.arms {
next_l := g.new_label()
g.emit_load(subj_idx)
g.gen_expr(arm.val)!
g.code << op_eq
g.code << op_jz
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: next_l, off: u32(g.code.len) - 8 }
for s in arm.body {
g.gen_stmt(s)!
}
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(next_l)
if i == st.arms.len - 1 && !st.has_else {
// no else: fall through to the end label
g.emit_label(end_l)
}
}
if st.has_else {
for s in st.els_body {
g.gen_stmt(s)!
}
g.emit_label(end_l)
}
}
.while_stmt {
loop_l := g.new_label()
end_l := g.new_label()
g.emit_label(loop_l)
g.gen_expr(st.cond)!
g.code << op_jz
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
g.loops << LoopCtx{ break_l: end_l, continue_l: loop_l }
for s in st.body {
g.gen_stmt(s)!
}
g.loops.delete_last()
g.code << op_jmp
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: loop_l, off: u32(g.code.len) - 8 }
g.emit_label(end_l)
}
.for_range_stmt {
// for i in a..b / for i in a...b → i := a; while i <(<=) b { body; i++ }
var_idx := g.new_local()
bound_idx := g.new_local()
loop_l := g.new_label()
inc_l := g.new_label()
end_l := g.new_label()
g.gen_expr(st.expr)!
g.gen_expr(st.cond)!
g.emit_store(bound_idx)
g.emit_store(var_idx)
g.emit_label(loop_l)
g.emit_load(var_idx)
g.emit_load(bound_idx)
g.code << if st.inclusive { op_le } else { op_lt }
g.code << op_jz
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
g.loops << LoopCtx{ break_l: end_l, continue_l: inc_l }
prev := g.locals[st.target] or { -1 }
prev_t := g.types[st.target] or { '' }
g.locals[st.target] = var_idx
g.types.delete(st.target)
for s in st.body {
g.gen_stmt(s)!
}
if prev >= 0 {
g.locals[st.target] = prev
} else {
g.locals.delete(st.target)
}
if prev_t.len > 0 {
g.types[st.target] = prev_t
}
g.loops.delete_last()
g.emit_label(inc_l)
g.emit_load(var_idx)
g.code << op_push_i
g.code << obj.encode_i64(1)
g.code << op_add
g.emit_store(var_idx)
g.code << op_jmp
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: loop_l, off: u32(g.code.len) - 8 }
g.emit_label(end_l)
}
.for_in_stmt {
// for x in arr → idx := 0; while idx < len(arr) { x := arr[idx]; body; idx++ }
arr_idx := g.new_local()
idx_idx := g.new_local()
elem_idx := g.new_local()
loop_l := g.new_label()
inc_l := g.new_label()
end_l := g.new_label()
g.gen_expr(st.expr)!
g.emit_store(arr_idx)
g.code << op_push_i
g.code << obj.encode_i64(0)
g.emit_store(idx_idx)
g.emit_label(loop_l)
g.emit_load(idx_idx)
g.emit_load(arr_idx)
g.code << op_alen
g.code << op_lt
g.code << op_jz
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
g.loops << LoopCtx{ break_l: end_l, continue_l: inc_l }
g.emit_load(arr_idx)
g.emit_load(idx_idx)
g.code << op_aget
g.emit_store(elem_idx)
prev := g.locals[st.target] or { -1 }
prev_t := g.types[st.target] or { '' }
g.locals[st.target] = elem_idx
g.types.delete(st.target)
for s in st.body {
g.gen_stmt(s)!
}
if prev >= 0 {
g.locals[st.target] = prev
} else {
g.locals.delete(st.target)
}
if prev_t.len > 0 {
g.types[st.target] = prev_t
}
g.loops.delete_last()
g.emit_label(inc_l)
g.emit_load(idx_idx)
g.code << op_push_i
g.code << obj.encode_i64(1)
g.code << op_add
g.emit_store(idx_idx)
g.code << op_jmp
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: loop_l, off: u32(g.code.len) - 8 }
g.emit_label(end_l)
}
.ret_stmt {
if st.has_val {
g.gen_expr(st.expr)!
g.code << op_retv
} else {
g.code << op_ret
}
}
.assert_stmt {
g.gen_expr(st.expr)!
g.code << op_assert
}
.break_stmt {
if g.loops.len == 0 {
return error('break outside of a loop (line ${st.line})')
}
ctx := g.loops[g.loops.len - 1]
g.code << op_jmp
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: ctx.break_l, off: u32(g.code.len) - 8 }
}
.continue_stmt {
if g.loops.len == 0 {
return error('continue outside of a loop (line ${st.line})')
}
ctx := g.loops[g.loops.len - 1]
g.code << op_jmp
g.code << obj.encode_i64(0)
g.fixups << Fixup{ name: ctx.continue_l, off: u32(g.code.len) - 8 }
}
}
}
fn (mut g Gen) gen_expr(e Expr) ! {
match e.kind {
.int_lit {
g.code << op_push_i
g.code << obj.encode_i64(e.int_v)
}
.str_lit {
// the index is a placeholder; the linker rebases it via a string
// relocation so multi-file links keep working
g.code << op_push_s
g.code << obj.encode_i64(0)
g.relocs << obj.Reloc{ offset: u32(g.code.len) - 8, name: e.str_v, kind: 1 }
}
.array_lit {
for el in e.elems {
g.gen_expr(el)!
}
g.code << op_mkarray
g.code << obj.encode_i64(i64(e.elems.len))
}
.struct_lit {
// typed literals validate their fields against the declaration
// (an undeclared type name is allowed — it may live in another
// file, where the same validation applies)
if e.name.len > 0 && e.name in g.structs {
decl_fields := g.structs[e.name]
mut seen := map[string]bool{}
for f in e.fields {
if f.name !in decl_fields {
return error('unknown field "${f.name}" for struct ${e.name} (line ${e.line})')
}
if f.name in seen {
return error('duplicate field "${f.name}" in struct literal (line ${e.line})')
}
seen[f.name] = true
}
}
// for each field: push the name string then the value; mkstruct n
// pops the (name, value) pairs and builds the record
for f in e.fields {
g.emit_field_name(f.name)
g.gen_expr(f.val)!
}
g.code << op_mkstruct
g.code << obj.encode_i64(i64(e.fields.len))
}
.field {
// check if it's an enum variant (e.g., Color.red)
if e.left.kind == .ident {
key := '${e.left.name}.${e.name}'
if key in g.enum_vals {
g.code << op_push_i
g.code << obj.encode_i64(i64(g.enum_vals[key]))
return
}
}
g.gen_expr(*e.left)!
g.emit_field_name(e.name)
g.code << op_sget
}
.method_call {
// p.dist(x) → call <Type>.dist p, x
recv_t := g.method_receiver_type(e)!
g.gen_expr(*e.left)!
for a in e.args {
g.gen_expr(a)!
}
g.code << op_call
g.code << obj.encode_i64(0) // placeholder — patched by the linker
g.relocs << obj.Reloc{ offset: u32(g.code.len) - 8, name: '${recv_t}.${e.name}', kind: 0 }
g.code << obj.encode_i64(i64(e.args.len + 1)) // receiver + args
}
.index {
g.gen_expr(*e.left)!
g.gen_expr(*e.right)!
g.code << op_aget
}
.bool_lit {
g.code << op_push_i
g.code << obj.encode_i64(e.int_v)
}
.ident {
// check if it's an enum variant (e.g., Color.red)
if e.name in g.enum_vals {
g.code << op_push_i
g.code << obj.encode_i64(i64(g.enum_vals[e.name]))
} else {
idx := g.locals[e.name] or {
return error('unknown variable "${e.name}" at line ${e.line}')
}
g.code << op_load
g.code << obj.encode_i64(i64(idx))
}
}
.unary {
g.gen_expr(*e.right)!
if e.op == .kw_not {
g.code << op_not
} else {
g.code << op_neg
}
}
.binary {
g.gen_binary(e)!
}
.call {
g.gen_call(e)!
}
}
}
fn (mut g Gen) gen_call(e Expr) ! {
if e.name == 'print' || e.name == 'println' {
if e.args.len != 1 {
return error('${e.name}() takes exactly one argument (line ${e.line})')
}
g.gen_expr(e.args[0])!
g.code << if e.name == 'print' { op_print } else { op_println }
return
}
if e.name == 'len' {
if e.args.len != 1 {
return error('len() takes exactly one argument (line ${e.line})')
}
g.gen_expr(e.args[0])!
g.code << op_alen
return
}
if e.name == 'push' {
if e.args.len != 2 {
return error('push() takes exactly two arguments (line ${e.line})')
}
g.gen_expr(e.args[0])!
g.gen_expr(e.args[1])!
g.code << op_apush
return
}
for a in e.args {
g.gen_expr(a)!
}
g.code << op_call
g.code << obj.encode_i64(0) // placeholder — patched by the linker
g.relocs << obj.Reloc{ offset: u32(g.code.len) - 8, name: e.name, kind: 0 }
g.code << obj.encode_i64(i64(e.args.len)) // argc
}
fn (mut g Gen) gen_binary(e Expr) ! {
match e.op {
.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 ${e.line}')
}
}
g.code << op
}
}
}
// expr_type returns the declared struct type of an expression when it is
// statically knowable: a typed literal `Point{...}`, a copy of a typed
// variable, or an enum variant `Enum.variant`. Everything else has no
// known type ('').
fn (mut g Gen) expr_type(e Expr) string {
if e.kind == .struct_lit {
return e.name
}
if e.kind == .ident {
return g.types[e.name] or { '' }
}
// enum variant: Color.red → type is "Color"
if e.kind == .field && e.left.kind == .ident {
key := '${e.left.name}.${e.name}'
if key in g.enum_vals {
return e.left.name
}
}
return ''
}
// method_receiver_type resolves the struct type a method call is made on.
// The receiver must be a plain variable whose type the compiler knows
// (from a typed literal, an assignment, or a method receiver binding).
fn (mut g Gen) method_receiver_type(e Expr) !string {
recv := e.left
if recv.kind == .ident {
t := g.types[recv.name] or { '' }
if t.len > 0 {
return t
}
}
return error('cannot resolve method "${e.name}": receiver type unknown (line ${e.line})')
}
// emit_field_name pushes a field name as a string constant. Like string
// literals it goes through a kind-1 relocation so multi-file links rebase it.
fn (mut g Gen) emit_field_name(name string) {
g.code << op_push_s
g.code << obj.encode_i64(0)
g.relocs << obj.Reloc{ offset: u32(g.code.len) - 8, name: name, kind: 1 }
}
fn (mut g Gen) intern(s string) int {
if s in g.str_map {
return g.str_map[s]
}
idx := g.strings.len
g.strings << s
g.str_map[s] = idx
return idx
}
fn (mut g Gen) new_local() int {
idx := g.local_cnt
g.local_cnt++
return idx
}
fn (mut g Gen) emit_load(idx int) {
g.code << op_load
g.code << obj.encode_i64(i64(idx))
}
fn (mut g Gen) emit_store(idx int) {
g.code << op_store
g.code << obj.encode_i64(i64(idx))
}
fn (mut g Gen) new_label() string {
g.next_lbl++
return 'L${g.next_lbl}'
}
fn (mut g Gen) emit_label(name string) {
g.labels[name] = g.code.len
}