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OxideJS/crates/oxide_emit/src/emit.rs
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//! emit:AST → IR 代码生成(parse → IR → bytecode 中段)。
//!
//! `Emitter` 提供各语法域的 emit_* 方法;核心状态集中在 `CompileCtx`:
//! 执行流字段(insts/registers/constants/labels)平铺其上,标识符绑定与
//! 闭包捕获分别下沉到 `SymbolTable` / `captured_bindings`。产出分域组合的
//! `IRFunction`,由 `oxide_ir::lower` 降为 bytecode。
use std::collections::{BTreeMap, HashMap, HashSet};
use oxide_bytecode::module::UpvalueCapture;
use oxide_bytecode::opcode::OpCode;
use oxide_ir::inst::Inst;
use oxide_ir::operand::{LabelId, Operand};
use oxide_ir::IRFunction;
/// 是否为匿名函数定义(剥括号):函数/箭头/class 表达式。
pub fn is_anonymous_function_definition(expr: &oxide_parser::Expression) -> bool {
match expr {
oxide_parser::Expression::ArrowFunctionExpression(_)
| oxide_parser::Expression::FunctionExpression(_)
| oxide_parser::Expression::ClassExpression(_) => true,
oxide_parser::Expression::ParenthesizedExpression(p) => is_anonymous_function_definition(&p.expression),
_ => false,
}
}
use crate::emit_ctx::{LabelCtx, ScopeCtx};
use crate::symbol_table::{Binding, ScopeKind, SymbolTable};
/// 常量池项(bytecode module 类型)re-export,供调用方构造常量。
pub use oxide_bytecode::module::Constant;
/// 变量声明种类(var/let/const),re-export 自 parser。
pub use oxide_parser::VariableDeclarationKind;
/// AST 语法树节点与运算符类型,re-export 自 parser。
pub use oxide_parser::{AssignmentOperator, BinaryOperator, Expression, Statement, UnaryOperator};
/// 编译入口(marker 类型)。方法按语法域组织在 `impl Emitter` 中。
pub struct Emitter;
/// 判断 f64 是否为整数值且在 i32 范围内(整数常量编码用)。
pub fn is_int_literal(value: f64) -> bool {
value.fract() == 0.0 && value >= i32::MIN as f64 && value <= i32::MAX as f64
}
/// 判断表达式是否无副作用(字面量/标识符/纯二元运算等)。
/// 用于可丢弃值的优化路径。
pub fn is_side_effect_free(expr: &Expression) -> bool {
let mut stack = vec![expr];
while let Some(expr) = stack.pop() {
match expr {
Expression::NumericLiteral(_)
| Expression::StringLiteral(_)
| Expression::BooleanLiteral(_)
| Expression::NullLiteral(_)
| Expression::Identifier(_)
| Expression::RegExpLiteral(_)
| Expression::ThisExpression(_) => {}
Expression::ParenthesizedExpression(p) => stack.push(&p.expression),
Expression::BinaryExpression(bin) => {
stack.push(&bin.left);
stack.push(&bin.right);
}
Expression::UnaryExpression(un) if !matches!(un.operator, UnaryOperator::Delete) => {
stack.push(&un.argument);
}
_ => return false,
}
}
true
}
const BUILTIN_GLOBALS: &[&str] = &[
"NaN",
"undefined",
"Infinity",
"globalThis",
"Object",
"Array",
"String",
"Number",
"Boolean",
"Function",
"Error",
"TypeError",
"ReferenceError",
"RangeError",
"SyntaxError",
"URIError",
"EvalError",
"Math",
"JSON",
"Promise",
"Date",
"Set",
"Map",
"RegExp",
"Symbol",
"parseInt",
"parseFloat",
"isNaN",
"isFinite",
"Proxy",
"WeakMap",
"WeakSet",
"WeakRef",
"FinalizationRegistry",
"Atomics",
"SharedArrayBuffer",
"ArrayBuffer",
"DataView",
"Iterator",
"BigInt",
"Int8Array",
"Uint8Array",
"Uint8ClampedArray",
"Int16Array",
"Uint16Array",
"Int32Array",
"Uint32Array",
"Float32Array",
"Float64Array",
"BigInt64Array",
"BigUint64Array",
"Reflect",
"escape",
"unescape",
"encodeURI",
"decodeURI",
"encodeURIComponent",
"decodeURIComponent",
];
pub(crate) struct FieldBuffer {
pub(crate) insts: Vec<Inst>,
pub(crate) labels: Vec<(LabelId, usize)>,
}
/// 标签语句作用域:编译期内登记 `break label` / `continue label` 的跳转目标。
/// `continue_label` 仅在标签直接包裹迭代语句时存在。
#[derive(Debug, Clone)]
pub struct LabelScope {
pub(crate) name: String,
pub(crate) break_label: LabelId,
pub(crate) continue_label: Option<LabelId>,
}
/// 单函数编译上下文:执行流 + 作用域 + 闭包捕获的聚合状态。
/// 指令、常量池、寄存器分配平铺于此,作用域/绑定见 `ScopeCtx`,跳转见 `LabelCtx`。
pub struct CompileCtx {
pub(crate) insts: Vec<Inst>,
pub(crate) constants: Vec<Constant>,
constant_map: HashMap<ConstantKey, u16>,
next_reg: u32,
pub(crate) max_regs: u32,
reserved_reg_start: u32,
pub(crate) labels: LabelCtx,
pub(crate) scopes: ScopeCtx,
pub(crate) nested: Vec<IRFunction>,
/// 外层函数上下文中持有 `this` 的寄存器。
/// 箭头函数用它捕获词法 `this`;顶层初始化为 254(约定 this 寄存器)。
pub(crate) enclosing_this_reg: u8,
pub(crate) in_derived_constructor: bool,
pub(crate) in_instance_method: bool,
pub(crate) in_static_method: bool,
pub(crate) static_block_this_reg: Option<u8>,
pub(crate) field_buffer: Option<FieldBuffer>,
pub(crate) current_upvalue_captures: Vec<UpvalueCapture>,
/// 本函数作用域声明的绑定名(参数 + 变量/函数声明,AST 收集,emit 前确定)。
pub(crate) own_bindings: HashSet<String>,
/// 本函数被嵌套函数捕获的绑定名 → cell_idx(名字排序分配,稳定跨 run)。
/// 捕获判断(MAKE_CELL / CELL_GET / CELL_SET)与子函数 upvalue cell_idx 统一查此映射,
/// 消除符号表时序依赖与 cell 索引错位。
pub(crate) captured_bindings: BTreeMap<String, u8>,
pub(crate) const_overflow: bool,
}
/// 函数体编译上下文:决定 `this`/`super` 绑定与参数前导(prologue)形态。
#[derive(Clone, Copy)]
pub enum FunctionBodyContext {
/// 普通函数:自身 `this`、独立作用域。
Ordinary,
/// 箭头函数:词法捕获外层 `this`,不生成参数前导。
Arrow,
/// 类元素方法:按类语义处理 `super` 与 home object。
ClassElement,
}
/// 参数规格:普通形参为标识符(可带默认值 initializer),解构形参用合成名 + 原始 pattern。
pub enum ParamSpec<'a> {
Identifier {
name: String,
initializer: Option<&'a Expression<'a>>,
},
Pattern {
synthetic_name: String,
pattern: &'a oxide_parser::BindingPattern<'a>,
initializer: Option<&'a Expression<'a>>,
},
}
impl ParamSpec<'_> {
pub(crate) fn register_name(&self) -> &str {
match self {
Self::Identifier { name, .. } => name,
Self::Pattern { synthetic_name, .. } => synthetic_name,
}
}
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
enum ConstantKey {
Number(u64),
Int(i32),
String(String),
Boolean(bool),
Null,
Undefined,
}
impl CompileCtx {
pub(crate) fn new() -> Self {
Self {
insts: Vec::new(),
constants: Vec::new(),
constant_map: HashMap::new(),
next_reg: 1,
max_regs: 1,
reserved_reg_start: 1,
labels: LabelCtx {
label_pos: Vec::new(),
loop_stack: Vec::new(),
switch_stack: Vec::new(),
label_scopes: Vec::new(),
pending_loop_labels: Vec::new(),
label_counter: 0,
},
scopes: ScopeCtx {
symbols: SymbolTable::new(),
builtin_reg_map: Vec::new(),
private_name_map: Vec::new(),
next_private_name_id: 1,
},
nested: Vec::new(),
enclosing_this_reg: 254, // conventional this register at top level
in_derived_constructor: false,
in_instance_method: false,
in_static_method: false,
static_block_this_reg: None,
field_buffer: None,
current_upvalue_captures: Vec::new(),
own_bindings: HashSet::new(),
captured_bindings: BTreeMap::new(),
const_overflow: false,
}
}
pub(crate) fn inst(&mut self, inst: Inst) {
self.insts.push(inst);
}
pub(crate) fn alloc_reg(&mut self) -> u32 {
let r = self.next_reg;
// vreg 化:寄存器号无上限,RegAlloc 阶段负责压缩到物理域(≤253)。
// 254/255 是 VM 保留的 this/new.target,vreg 世界允许虚拟号越过它们,
// 只有 RegAlloc 完成映射后 lower 的物理域检查才相关。
self.next_reg += 1;
if self.next_reg > self.max_regs {
self.max_regs = self.next_reg;
}
r
}
pub(crate) fn reset_regs(&mut self) {
self.next_reg = self.builtin_reg_floor().max(self.reserved_reg_start);
self.labels.label_counter = 0;
}
pub(crate) fn reserve_reg(&mut self, reg: u32) {
let next = reg.wrapping_add(1);
if self.next_reg <= reg {
self.next_reg = next;
}
if self.max_regs < next {
self.max_regs = next;
}
}
pub(crate) fn add_constant(&mut self, c: Constant) -> u16 {
if let Some(key) = ConstantKey::from_constant(&c) {
if let Some(&idx) = self.constant_map.get(&key) {
return idx;
}
if self.constants.len() >= u16::MAX as usize {
self.const_overflow = true;
return u16::MAX;
}
let idx = self.constants.len() as u16;
self.constants.push(c);
self.constant_map.insert(key, idx);
return idx;
}
let idx = self.constants.len();
if idx >= u16::MAX as usize {
self.const_overflow = true;
return u16::MAX;
}
self.constants.push(c);
idx as u16
}
pub(crate) fn push_scope(&mut self) {
self.scopes.symbols.push_scope();
}
pub(crate) fn pop_scope(&mut self) {
self.scopes.symbols.pop_scope();
}
pub(crate) fn declare(
&mut self, name: &str, reg: u32, kind: VariableDeclarationKind, is_const: bool,
) -> Result<(), String> {
self.scopes.symbols.declare(name, reg, kind, is_const)
}
pub(crate) fn declare_initialized(
&mut self, name: &str, reg: u32, kind: VariableDeclarationKind, is_const: bool,
) -> Result<(), String> {
self.scopes.symbols.declare_initialized(name, reg, kind, is_const)
}
pub(crate) fn push_scope_with_kind(&mut self, kind: ScopeKind) {
self.scopes.symbols.push_scope_with_kind(kind);
}
pub(crate) fn lookup(&self, name: &str) -> Result<u32, String> {
self.scopes.symbols.lookup(name)
}
pub(crate) fn lookup_or_builtin(&mut self, name: &str) -> Result<u32, String> {
match self.scopes.symbols.lookup(name) {
Ok(reg) => Ok(reg),
Err(err) if Self::is_known_builtin(name) && err.contains("is not defined") => {
let reg = self.alloc_reg();
self.scopes.symbols.pre_register_global(name, reg);
self.scopes.builtin_reg_map.push((name.to_string(), reg));
Ok(reg)
}
Err(err) => Err(err),
}
}
pub(crate) fn lookup_or_global(&mut self, name: &str) -> u32 {
if let Some(reg) = self.scopes.symbols.lookup_any(name) {
return reg;
}
let reg = self.alloc_reg();
self.scopes.symbols.lookup_or_global(name, reg)
}
pub(crate) fn lookup_const_flag(&self, name: &str) -> bool {
self.scopes.symbols.lookup_is_const(name)
}
pub(crate) fn init_var(&mut self, name: &str) {
self.scopes.symbols.init_var(name);
}
pub(crate) fn next_label_id(&mut self) -> u32 {
let id = self.labels.label_counter;
self.labels.label_counter += 1;
id
}
pub(crate) fn push_loop(&mut self, break_label: LabelId, continue_label: LabelId) {
self.labels.loop_stack.push((break_label, continue_label));
}
pub(crate) fn pop_loop(&mut self) {
self.labels.loop_stack.pop();
}
pub(crate) fn current_loop(&self) -> Option<&(LabelId, LabelId)> {
self.labels.loop_stack.last()
}
pub(crate) fn push_switch(&mut self, break_label: LabelId) {
self.labels.switch_stack.push(break_label);
}
pub(crate) fn pop_switch(&mut self) {
self.labels.switch_stack.pop();
}
pub(crate) fn current_switch(&self) -> Option<&LabelId> {
self.labels.switch_stack.last()
}
pub(crate) fn push_label_scope(
&mut self, name: &str, break_label: LabelId, continue_label: Option<LabelId>,
) -> Result<(), String> {
if self.labels.label_scopes.iter().any(|s| s.name == name) {
return Err(format!("SyntaxError: Label '{name}' has already been declared"));
}
self.labels.label_scopes.push(LabelScope {
name: name.to_string(),
break_label,
continue_label,
});
Ok(())
}
pub(crate) fn pop_label_scope(&mut self) {
self.labels.label_scopes.pop();
}
pub(crate) fn find_label(&self, name: &str) -> Option<&LabelScope> {
self.labels.label_scopes.iter().rev().find(|s| s.name == name)
}
/// 登记一个待绑定标签名:该标签将作为下一个 emit 的循环(标签语句体)的
/// continue 目标。活动集合与待绑定集合中出现重名报错。
pub(crate) fn queue_loop_label(&mut self, name: &str) -> Result<(), String> {
if self.labels.label_scopes.iter().any(|s| s.name == name)
|| self.labels.pending_loop_labels.iter().any(|n| n == name)
{
return Err(format!("SyntaxError: Label '{name}' has already been declared"));
}
self.labels.pending_loop_labels.push(name.to_string());
Ok(())
}
/// 把待绑定标签名落地为活动标签作用域,绑定到本次循环的 break/continue 目标。
/// 返回压入的作用域个数(供事后对称弹出)。
pub(crate) fn take_pending_loop_labels(&mut self, break_label: LabelId, continue_label: LabelId) -> usize {
let names = std::mem::take(&mut self.labels.pending_loop_labels);
let count = names.len();
for name in names {
self.labels.label_scopes.push(LabelScope {
name,
break_label,
continue_label: Some(continue_label),
});
}
count
}
pub(crate) fn pop_label_scopes(&mut self, n: usize) {
for _ in 0..n {
self.labels.label_scopes.pop();
}
}
pub(crate) fn is_builtin(&self, name: &str) -> bool {
self.scopes.builtin_reg_map.iter().any(|(n, _)| n == name)
}
pub(crate) fn is_known_builtin(name: &str) -> bool {
BUILTIN_GLOBALS.contains(&name)
}
fn builtin_reg_floor(&self) -> u32 {
self.scopes
.builtin_reg_map
.iter()
.map(|(_, reg)| reg.saturating_add(1))
.max()
.unwrap_or(0)
}
pub(crate) fn pre_register_builtins(&mut self) {
// builtin 全局由 lookup_or_builtin() 惰性解析。保留此钩子维持编译管线形态,
// 避免在每个模块预留约 60 个寄存器槽。
}
/// 组装 IRFunction(两出口共用),take 走编译产物状态。
/// `parent_ctx` 用于补全 upvalue_captures 的 enclosing_reg(父符号表在父 emit 完成后完整)。
fn assemble_ir(&mut self, param_layout: oxide_ir::ParamLayout, parent_ctx: Option<&CompileCtx>) -> IRFunction {
let upvalue_captures = self
.current_upvalue_captures
.iter()
.map(|u| {
let enclosing_reg = parent_ctx
.and_then(|p| p.scopes.symbols.lookup_any(u.name.as_str()))
.unwrap_or(0);
UpvalueCapture {
name: u.name.clone(),
enclosing_reg,
cell_idx: u.cell_idx,
parent_uv_idx: u.parent_uv_idx,
}
})
.collect();
IRFunction {
insts: std::mem::take(&mut self.insts),
label_pos: std::mem::take(&mut self.labels.label_pos),
label_count: self.labels.label_counter,
constants: std::mem::take(&mut self.constants),
param_layout,
builtin_reg_map: std::mem::take(&mut self.scopes.builtin_reg_map),
upvalue_captures,
cells_needed: self.captured_bindings.len() as u8,
n_registers: self.max_regs,
is_arrow: false,
is_class_constructor: false,
is_derived_constructor: false,
needs_home_object: false,
captured_this_const_idx: 0,
function_name: None,
is_top_level: parent_ctx.is_none(),
const_overflow: self.const_overflow,
nested: std::mem::take(&mut self.nested),
}
}
}
impl ConstantKey {
fn from_constant(value: &Constant) -> Option<Self> {
match value {
Constant::Number(v) => Some(Self::Number(v.to_bits())),
Constant::Int(v) => Some(Self::Int(*v)),
Constant::String(v) => Some(Self::String(v.clone())),
Constant::Boolean(v) => Some(Self::Boolean(*v)),
Constant::Null => Some(Self::Null),
Constant::Undefined => Some(Self::Undefined),
}
}
}
impl Emitter {
/// 构造空 `Emitter`(无内部状态,所有状态在 `CompileCtx` 中)。
pub fn new() -> Self {
Self
}
/// 遍历解构 pattern 收集内嵌默认值表达式(AssignmentPattern.right)。
fn collect_pattern_default_exprs<'a>(
&self, pattern: &'a oxide_parser::BindingPattern<'a>, out: &mut Vec<&'a oxide_parser::Expression<'a>>,
) {
use oxide_parser::BindingPattern;
match pattern {
BindingPattern::AssignmentPattern(ap) => {
out.push(&ap.right);
self.collect_pattern_default_exprs(&ap.left, out);
}
BindingPattern::ArrayPattern(ap) => {
for elem in &ap.elements {
if let Some(p) = elem {
self.collect_pattern_default_exprs(p, out);
}
}
if let Some(rest) = &ap.rest {
self.collect_pattern_default_exprs(&rest.argument, out);
}
}
BindingPattern::ObjectPattern(op) => {
for prop in &op.properties {
self.collect_pattern_default_exprs(&prop.value, out);
}
if let Some(rest) = &op.rest {
self.collect_pattern_default_exprs(&rest.argument, out);
}
}
_ => {}
}
}
// ── 闭包捕获分析(AST 级,时序无关)──
/// 收集函数参数的绑定名(BindingIdentifier 形态)。
pub(crate) fn extract_function_parts<'a>(
&self, function: &'a oxide_parser::Function<'a>,
) -> Result<(Vec<ParamSpec<'a>>, &'a [Statement<'a>]), String> {
let mut param_specs = Vec::new();
for (idx, param) in function.params.items.iter().enumerate() {
match &param.pattern {
oxide_parser::BindingPattern::BindingIdentifier(bi) => {
param_specs.push(ParamSpec::Identifier {
name: bi.name.to_string(),
initializer: param.initializer.as_deref(),
});
}
pattern => {
param_specs.push(ParamSpec::Pattern {
synthetic_name: format!("@@param_{idx}"),
pattern,
initializer: param.initializer.as_deref(),
});
}
}
}
let body_stmts: &[Statement] = if let Some(body) = &function.body { &body.statements } else { &[] };
Ok((param_specs, body_stmts))
}
/// 编译函数体(函数声明/函数表达式/箭头函数共用),单 pass 完成发码。
///
/// `is_expression_body` 为 true(箭头表达式体)时返回最后一个表达式的值,
/// 否则返回 undefined。`is_arrow` 控制 super 相关标志的继承:箭头函数词法
/// 继承外层 super,普通函数重置 super 作用域。
pub(crate) fn compile_function_body<'a>(
&self, param_specs: &[ParamSpec<'a>], body_stmts: &[Statement<'a>], parent_ctx: &CompileCtx,
is_expression_body: bool, is_arrow: bool,
) -> Result<IRFunction, String> {
let body_context = if is_arrow {
FunctionBodyContext::Arrow
} else {
FunctionBodyContext::Ordinary
};
self.compile_function_body_with_bindings(
param_specs,
body_stmts,
parent_ctx,
is_expression_body,
&[],
body_context,
)
}
pub(crate) fn compile_function_body_with_bindings<'a>(
&self, param_specs: &[ParamSpec<'a>], body_stmts: &[Statement<'a>], parent_ctx: &CompileCtx,
is_expression_body: bool, extra_bindings: &[(&str, u32)], body_context: FunctionBodyContext,
) -> Result<IRFunction, String> {
self.compile_function_body_with_field_hooks(
param_specs,
body_stmts,
parent_ctx,
is_expression_body,
extra_bindings,
body_context,
None::<fn(&Emitter, &mut CompileCtx) -> Result<(), String>>,
false,
)
}
/// 预注册 builtin 引用并编译函数体(普通/箭头/类元素方法共用入口)。
///
/// 本函数体内任意位置(表达式、成员对象、调用实参、类字段等)引用的内置全局
/// 标识符,其寄存器槽都先于任何临时寄存器登记。
///
/// vreg 化后临时值不复用(独立 vreg),但 builtin 槽预注册仍保证分配序稳定:
/// builtin 槽先于临时值池,嵌套函数继承边界不受扰。
#[allow(clippy::too_many_arguments)]
pub(crate) fn compile_function_body_with_field_hooks<'a, E>(
&self, param_specs: &[ParamSpec<'a>], body_stmts: &[Statement<'a>], parent_ctx: &CompileCtx,
is_expression_body: bool, extra_bindings: &[(&str, u32)], body_context: FunctionBodyContext,
mut emit_fields: Option<E>, fields_after_super: bool,
) -> Result<IRFunction, String>
where
E: FnMut(&Emitter, &mut CompileCtx) -> Result<(), String>,
{
let mut ctx = CompileCtx::new();
// 继承父内置寄存器映射:子模块寄存器文件中,内置标识符(Math、Object 等)
// 解析到父预先分配的槽位。
ctx.scopes.builtin_reg_map = parent_ctx.scopes.builtin_reg_map.clone();
ctx.scopes.private_name_map = parent_ctx.scopes.private_name_map.clone();
ctx.scopes.next_private_name_id = parent_ctx.scopes.next_private_name_id;
// 传递 enclosing_this_reg:嵌套箭头函数捕获正确的 `this`。
ctx.enclosing_this_reg = parent_ctx.enclosing_this_reg;
// 箭头函数词法继承 super;类方法体顶层编译也需要类提供的 super 上下文。
if matches!(body_context, FunctionBodyContext::Arrow | FunctionBodyContext::ClassElement) {
ctx.in_derived_constructor = parent_ctx.in_derived_constructor;
ctx.in_instance_method = parent_ctx.in_instance_method;
ctx.in_static_method = parent_ctx.in_static_method;
} else {
ctx.in_derived_constructor = false;
ctx.in_instance_method = false;
ctx.in_static_method = false;
}
// 继承父全局作用域条目:先前声明的函数名在函数体内可见。
let mut inherited_reg_start = 1u32.max(ctx.builtin_reg_floor());
for (name, binding) in &parent_ctx.scopes.symbols.scopes[0].bindings {
ctx.scopes.symbols.scopes[0].bindings.insert(
name.clone(),
Binding {
reg: binding.reg,
initialized: binding.initialized,
is_const: binding.is_const,
},
);
inherited_reg_start = inherited_reg_start.max(binding.reg.saturating_add(1));
}
for (name, reg) in extra_bindings {
ctx.scopes.symbols.scopes[0].bindings.insert(
(*name).to_string(),
Binding {
reg: *reg,
initialized: true,
is_const: true,
},
);
inherited_reg_start = inherited_reg_start.max(reg.saturating_add(1));
}
ctx.reserved_reg_start = inherited_reg_start.max(1);
// 让 next_reg 与 builtin 槽位对齐,参数在 builtin 槽之后分配。
ctx.reset_regs();
let param_base = self.emit_params_prologue(param_specs, body_stmts, parent_ctx, &mut ctx, body_context)?;
self.predeclare_function_declarations(body_stmts, &mut ctx);
// 预注册 builtin 引用(先于任何临时寄存器),builtin 槽不与被复用的临时值冲突。
self.pre_register_builtin_references(body_stmts, &mut ctx);
// 预声明 `var` 名,使首个 sub-pass 中提升的函数声明能解析其闭包引用的外层 var。
self.predeclare_var_declarations(body_stmts, &mut ctx);
if let Some(emit) = emit_fields.as_mut() {
if fields_after_super {
let mut parent_insts = Vec::new();
let mut parent_label_pos = Vec::new();
std::mem::swap(&mut ctx.insts, &mut parent_insts);
std::mem::swap(&mut ctx.labels.label_pos, &mut parent_label_pos);
emit(self, &mut ctx)?;
let field_buffer = FieldBuffer {
insts: std::mem::take(&mut ctx.insts),
labels: std::mem::take(&mut ctx.labels.label_pos)
.into_iter()
.enumerate()
.filter_map(|(id, pos)| pos.map(|p| (id as LabelId, p)))
.collect(),
};
ctx.insts = parent_insts;
ctx.labels.label_pos = parent_label_pos;
ctx.field_buffer = Some(field_buffer);
} else {
emit(self, &mut ctx)?;
}
}
// 发 body 语句(先函数声明 hoisting,再其余)。
let last_result_reg = self.emit_body_stmts(body_stmts, &mut ctx)?;
// 隐式 RETURN:表达式体返回最后表达式,语句体返回 undefined。
if is_expression_body {
if let Some(reg) = last_result_reg {
ctx.inst(Inst::new(OpCode::RETURN, Operand::Reg(reg), Operand::None, Operand::None));
} else {
let undef_idx = ctx.add_constant(Constant::Undefined);
let undef_reg = ctx.alloc_reg();
ctx.inst(Inst::load_const(Operand::Reg(undef_reg), undef_idx));
ctx.inst(Inst::new(OpCode::RETURN, Operand::Reg(undef_reg), Operand::None, Operand::None));
}
} else {
let undef_idx = ctx.add_constant(Constant::Undefined);
let undef_reg = ctx.alloc_reg();
ctx.inst(Inst::load_const(Operand::Reg(undef_reg), undef_idx));
ctx.inst(Inst::new(OpCode::RETURN, Operand::Reg(undef_reg), Operand::None, Operand::None));
}
let ir = ctx.assemble_ir(
oxide_ir::ParamLayout {
base: param_base,
count: param_specs.len() as u32,
},
Some(parent_ctx),
);
Ok(ir)
}
/// 参数 prologue:函数作用域 + 参数声明/解构 + 闭包捕获与 upvalue 分析。返回 param_base。
fn emit_params_prologue<'a>(
&self, param_specs: &[ParamSpec<'a>], body_stmts: &[Statement<'a>], parent_ctx: &CompileCtx,
ctx: &mut CompileCtx, body_context: FunctionBodyContext,
) -> Result<u32, String> {
ctx.push_scope_with_kind(ScopeKind::FunctionScope);
let param_base = ctx.next_reg;
// 发参数声明(分配寄存器;分析用 register_name 引用)。
for spec in param_specs {
let name = spec.register_name();
let reg = ctx.alloc_reg();
ctx.declare_initialized(name, reg, VariableDeclarationKind::Var, false)?;
}
// 闭包捕获分析(AST 级,emit 前确定):须在参数默认值 emit 之前,
// 否则默认值内嵌套函数(IIFE)编译时父分析为空 → upvalue 捕获丢失。
let param_names: Vec<&str> = param_specs.iter().map(|s| s.register_name()).collect();
let mut param_defaults: Vec<&oxide_parser::Expression> = Vec::new();
for spec in param_specs {
match spec {
ParamSpec::Identifier { initializer, .. } => {
if let Some(init) = initializer {
param_defaults.push(init);
}
}
ParamSpec::Pattern { pattern, initializer, .. } => {
if let Some(init) = initializer {
param_defaults.push(init);
}
// 模式内嵌默认值(`[x = expr]` 的 AssignmentPattern.right)也会被
// 内部闭包引用,需纳入捕获分析。
self.collect_pattern_default_exprs(pattern, &mut param_defaults);
}
}
}
ctx.own_bindings = self.collect_own_binding_names(&param_names, body_stmts);
// 自动声明 arguments 绑定(非箭头函数,且用户未显式声明同名标识符)。
// 先登记符号并纳入 own_bindings,使嵌套箭头引用 arguments 被识别为本函数
// 绑定(否则被当自由变量 → 子模块 upvalue 解析错位)。
let mut arguments_reg = None;
if !matches!(body_context, FunctionBodyContext::Arrow) && !ctx.own_bindings.contains("arguments") {
let reg = ctx.alloc_reg();
ctx.declare_initialized("arguments", reg, VariableDeclarationKind::Var, false)?;
ctx.own_bindings.insert("arguments".to_string());
arguments_reg = Some(reg);
}
ctx.captured_bindings = self.collect_captured_bindings(body_stmts, &param_defaults, &ctx.own_bindings);
// 自由变量分析:收集 upvalue 捕获(类方法也是普通函数,可捕获外层变量)。
if matches!(
body_context,
FunctionBodyContext::Ordinary | FunctionBodyContext::Arrow | FunctionBodyContext::ClassElement
) {
ctx.current_upvalue_captures = self.collect_upvalue_names(
body_stmts,
&param_defaults,
&parent_ctx.captured_bindings,
&parent_ctx.current_upvalue_captures,
&ctx.own_bindings,
);
}
// 创建 arguments 对象:指令须在默认参数求值前发出(默认参数可引用 arguments)。
if let Some(reg) = arguments_reg {
ctx.inst(Inst::create_arguments(Operand::Reg(reg)));
}
for spec in param_specs {
match spec {
ParamSpec::Pattern { synthetic_name, pattern, initializer } => {
let src_reg = ctx.lookup(synthetic_name)?;
let src_reg = if let Some(init) = initializer {
self.emit_default_if_undefined(src_reg, init, Some(synthetic_name), ctx)?
} else {
src_reg
};
self.emit_binding_pattern(pattern, src_reg, VariableDeclarationKind::Var, false, ctx)?;
}
ParamSpec::Identifier { name, initializer } => {
if let Some(init) = initializer {
// 默认参数:实参为 undefined 时用默认值。
let reg = ctx.lookup(name)?;
self.emit_default_if_undefined(reg, init, Some(name), ctx)?;
}
}
}
}
// 被捕获的参数也必须建 cell(MAKE_CELL):否则子函数经 lazy upvalue 路径读
// 自身寄存器(依赖调用者寄存器残留),vreg 化/RegAlloc 移动寄存器后读到垃圾。
// 与 var/let/const 的 MAKE_CELL 语义一致(binding.rs:50)。须在默认值之后
// (默认值 emit 会读参数寄存器)。
for spec in param_specs {
let name = spec.register_name();
if let Some(&cell_idx) = ctx.captured_bindings.get(name) {
let reg = ctx.lookup(name)?;
ctx.inst(Inst::new(
OpCode::MAKE_CELL,
Operand::Reg(reg),
Operand::Imm(cell_idx as u16),
Operand::None,
));
}
}
// 被捕获的 arguments 绑定同样建 cell(与参数一致,须在默认值之后)。
if let (Some(reg), Some(&cell_idx)) = (arguments_reg, ctx.captured_bindings.get("arguments")) {
ctx.inst(Inst::new(
OpCode::MAKE_CELL,
Operand::Reg(reg),
Operand::Imm(cell_idx as u16),
Operand::None,
));
}
Ok(param_base)
}
/// 双 sub-pass emit body:先函数声明(hoisting),再其余语句。返回最后结果寄存器。
fn emit_body_stmts(&self, body_stmts: &[Statement], ctx: &mut CompileCtx) -> Result<Option<u32>, String> {
let mut last_result_reg = None;
for stmt in body_stmts {
if matches!(stmt, Statement::FunctionDeclaration(_)) {
if let Some(reg) = self.emit_statement(stmt, ctx)? {
last_result_reg = Some(reg);
}
}
}
for stmt in body_stmts {
if matches!(stmt, Statement::FunctionDeclaration(_)) {
continue;
}
if let Some(reg) = self.emit_statement(stmt, ctx)? {
last_result_reg = Some(reg);
}
}
Ok(last_result_reg)
}
pub(crate) fn emit_statement(&self, stmt: &Statement, ctx: &mut CompileCtx) -> Result<Option<u32>, String> {
match stmt {
Statement::ExpressionStatement(_) | Statement::ReturnStatement(_) | Statement::EmptyStatement(_) => {
self.emit_basic_domain(stmt, ctx)
}
Statement::BlockStatement(_) => self.emit_block_domain(stmt, ctx),
Statement::VariableDeclaration(_) | Statement::FunctionDeclaration(_) | Statement::ClassDeclaration(_) => {
self.emit_declaration_domain(stmt, ctx)
}
Statement::IfStatement(_) => self.emit_control_domain(stmt, ctx),
Statement::WhileStatement(_)
| Statement::DoWhileStatement(_)
| Statement::ForStatement(_)
| Statement::ForInStatement(_)
| Statement::ForOfStatement(_) => self.emit_iteration_domain(stmt, ctx),
Statement::SwitchStatement(_) => self.emit_switch_domain(stmt, ctx),
Statement::ThrowStatement(_) | Statement::TryStatement(_) => self.emit_exception_domain(stmt, ctx),
Statement::BreakStatement(b) => self.emit_break_statement(b, ctx),
Statement::ContinueStatement(c) => self.emit_continue_statement(c, ctx),
Statement::LabeledStatement(ls) => self.emit_labeled_statement(ls, ctx),
_ => Ok(None),
}
}
pub(crate) fn emit_expression(&self, expr: &Expression, ctx: &mut CompileCtx) -> Result<u32, String> {
match expr {
Expression::NumericLiteral(_)
| Expression::StringLiteral(_)
| Expression::BooleanLiteral(_)
| Expression::NullLiteral(_)
| Expression::RegExpLiteral(_) => self.emit_literal(expr, ctx),
Expression::BinaryExpression(_)
| Expression::PrivateInExpression(_)
| Expression::UnaryExpression(_)
| Expression::ConditionalExpression(_)
| Expression::LogicalExpression(_)
| Expression::UpdateExpression(_) => self.emit_operator(expr, ctx),
Expression::StaticMemberExpression(_)
| Expression::ComputedMemberExpression(_)
| Expression::PrivateFieldExpression(_)
| Expression::ChainExpression(_) => self.emit_member_domain(expr, ctx),
Expression::ObjectExpression(_) | Expression::ArrayExpression(_) => self.emit_object_domain(expr, ctx),
Expression::AssignmentExpression(assign) => self.emit_assignment_expression(assign, ctx),
Expression::TemplateLiteral(_) | Expression::TaggedTemplateExpression(_) => {
self.emit_template_domain(expr, ctx)
}
Expression::ArrowFunctionExpression(_)
| Expression::FunctionExpression(_)
| Expression::ClassExpression(_)
| Expression::NewExpression(_) => self.emit_function_domain(expr, ctx),
Expression::Identifier(ident) => self.emit_identifier_expression(ident, ctx),
Expression::CallExpression(_) => self.emit_call_domain(expr, ctx),
Expression::ThisExpression(_) => self.emit_this_expression(ctx),
Expression::SequenceExpression(seq) => self.emit_sequence_expression(seq, ctx),
Expression::ParenthesizedExpression(p) => self.emit_parenthesized_expression(p, ctx),
_ => self.emit_unsupported_expression(expr, ctx),
}
}
/// 把完整程序编译为顶层模块体的 IRFunction。
///
/// 调用方为 `oxide_compiler::Compiler::compile`:本函数完成 emit 半程,
/// 随后由 `oxide_ir::lower::lower` 降为字节码。
pub fn emit_program(&self, program: &oxide_parser::Program) -> Result<IRFunction, String> {
let mut ctx = CompileCtx::new();
ctx.pre_register_builtins();
self.predeclare_function_declarations(&program.body, &mut ctx);
// 预注册 builtin 引用(先于任何临时寄存器),builtin 槽不进入临时寄存器池。
self.pre_register_builtin_references(&program.body, &mut ctx);
// 预声明顶层 `var` 名,使首个 sub-pass 中提升的函数声明能解析外层 var。
self.predeclare_var_declarations(&program.body, &mut ctx);
// 闭包捕获分析(AST 级,emit 前确定)
ctx.own_bindings = self.collect_own_binding_names(&[], &program.body);
ctx.captured_bindings = self.collect_captured_bindings(&program.body, &[], &ctx.own_bindings);
// 首个 sub-pass:发函数声明(hoisting),保证任何代码运行前函数对象已就绪。
for stmt in &program.body {
if matches!(stmt, Statement::FunctionDeclaration(_)) {
self.emit_statement(stmt, &mut ctx)?;
}
}
// 第二个 sub-pass:发其余所有语句。
let mut last_result: Option<u32> = None;
for stmt in &program.body {
if matches!(stmt, Statement::FunctionDeclaration(_)) {
continue; // Already emitted above
}
match self.emit_statement(stmt, &mut ctx)? {
Some(r) => last_result = Some(r),
None => last_result = None,
}
}
if let Some(r) = last_result {
ctx.inst(Inst::new(OpCode::LOAD_VAR, Operand::None, Operand::Reg(r), Operand::None));
} else {
let undef_idx = ctx.add_constant(Constant::Undefined);
ctx.inst(Inst::load_const(Operand::None, undef_idx));
}
ctx.inst(Inst::new(OpCode::HALT, Operand::None, Operand::None, Operand::None));
let ir = ctx.assemble_ir(
oxide_ir::ParamLayout {
// 顶层模块无父函数:base 恒 0。曾用 builtin_reg_map.len(),harness 前缀
// 大时把模块自身低号 vreg 误判为父槽 → 恒等色收缩可分配色集、spill 增多。
base: 0,
count: 0,
},
None,
);
Ok(ir)
}
}
impl Default for Emitter {
fn default() -> Self {
Self::new()
}
}