pjh123
a8378694be
return/break/continue 逃出 for-of 时此前完全不执行 IteratorClose： BREAK/CONTINUE/RETURN 指令现在经 ext 字携带词法逃出的迭代器层数 （for-of + for-in 各 16 位），运行时在全部 finally 穿越之后、真正 跳转/返回之前按 LIFO 关闭——与规范 §13.7.5.4（循环体完成值已含 内部 try-finally 处理，IteratorClose 在后）顺序一致。 - emit 词法：LabelCtx 增加 for-of/for-in 深度计数，loop/switch/label 打开时快照，break/continue/return 按当前深度减目标深度计算逃出层数 （switch 内 break 以 switch 打开点为基准，目标循环自身不计入） - 指令编码：brk/cont/ret 三参构造，lower 跳转路径补发 ext 字 - 运行时：dispatch_break/continue/return 读取逃出计数，无 finally 时 直接关闭后跳转/返回，有 finally 时随 Completion 悬挂由 TRY_FINALLY_END 在穿越完成后消费；生成器 .return()/.throw() 注入经 complete_generator_return 全关快照栈迭代器；return() 抛错经 unwind 替代完成值并关闭剩余迭代器 - 顺带：for-in 逃出残留（无 return() 语义，仅弹栈）；for-await-of 的 异步迭代器不做同步关闭（return() promise 须 await，走异步机制） - 新增 15 项回归测试：return/labeled break/continue/switch/while/finally 顺序/抛错优先/生成器注入/for-in/for-await-of 嵌套
97 lines
4.5 KiB
Rust
97 lines
4.5 KiB
Rust
//! break/continue 语句 emit：解析标签与最近循环的跳转目标。
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//!
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//! 计算 break/continue 逃出的 finally 域数（目标打开时的 finally 深度与当前深度之差）
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//! 与逃出的迭代器层数（for-of/for-in 深度之差，目标循环自身的关闭由 CLOSE /
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//! FOR_IN_CLEANUP 处理，不计入）：逃出 ≥1 个 finally 域或 ≥1 层迭代器 → 发
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//! BREAK/CONTINUE（运行时穿越 finally、关闭逃出迭代器后再跳转）；否则发普通 JMP。
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use crate::{CompileCtx, Emitter};
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use oxide_ir::inst::Inst;
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impl Emitter {
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pub(crate) fn emit_break_statement(
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&self, stmt: &oxide_parser::BreakStatement, ctx: &mut CompileCtx,
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) -> Result<Option<u32>, String> {
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let (break_label, fd_at_open, fod_at_open, fid_at_open) = if let Some(label) = &stmt.label {
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let name = label.name.as_str();
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let scope = ctx
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.find_label(name)
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.ok_or_else(|| format!("SyntaxError: Undefined label '{name}'"))?;
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(
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scope.break_label,
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scope.finally_depth_at_open,
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scope.for_of_depth_at_open,
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scope.for_in_depth_at_open,
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)
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} else if let Some((sw_label, fd, fod, fid)) = ctx.current_switch() {
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// switch 内 break：目标为 switch 出口。逃出计数以 switch 打开时的
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// 深度快照为基准——switch 之前已打开的循环不属于本次逃出，仅当
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// case 内新打开了迭代循环（并逃出）时才需关闭。
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(*sw_label, *fd, *fod, *fid)
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} else {
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let entry = ctx.current_loop().ok_or("break outside switch or loop".to_string())?;
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(
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entry.break_label,
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entry.finally_depth_at_open,
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entry.for_of_depth_at_open,
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entry.for_in_depth_at_open,
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)
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};
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let crossed = ctx.labels.finally_depth.saturating_sub(fd_at_open) as u16;
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let (for_of_count, for_in_count) = escape_iter_counts(ctx, fod_at_open, fid_at_open);
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if crossed > 0 || for_of_count > 0 || for_in_count > 0 {
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ctx.inst(Inst::brk(break_label, crossed, for_of_count, for_in_count));
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} else {
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ctx.inst(Inst::jmp(break_label));
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}
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Ok(None)
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}
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pub(crate) fn emit_continue_statement(
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&self, stmt: &oxide_parser::ContinueStatement, ctx: &mut CompileCtx,
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) -> Result<Option<u32>, String> {
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let (continue_label, fd_at_open, fod_at_open, fid_at_open) = if let Some(label) = &stmt.label {
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let name = label.name.as_str();
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let scope = ctx
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.find_label(name)
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.ok_or_else(|| format!("SyntaxError: Undefined label '{name}'"))?;
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(
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scope.continue_label.ok_or_else(|| {
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format!("SyntaxError: Illegal continue statement: '{name}' does not denote an iteration statement")
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})?,
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scope.finally_depth_at_open,
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scope.for_of_depth_at_open,
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scope.for_in_depth_at_open,
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)
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} else {
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let entry = ctx.current_loop().ok_or("continue outside loop".to_string())?;
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(
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entry.continue_label,
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entry.finally_depth_at_open,
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entry.for_of_depth_at_open,
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entry.for_in_depth_at_open,
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)
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};
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let crossed = ctx.labels.finally_depth.saturating_sub(fd_at_open) as u16;
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let (for_of_count, for_in_count) = escape_iter_counts(ctx, fod_at_open, fid_at_open);
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if crossed > 0 || for_of_count > 0 || for_in_count > 0 {
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ctx.inst(Inst::cont(continue_label, crossed, for_of_count, for_in_count));
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} else {
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ctx.inst(Inst::jmp(continue_label));
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}
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Ok(None)
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}
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}
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/// 计算逃出目标循环需要关闭的 for-of / for-in 迭代器层数。
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///
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/// 深度快照（`fod_at_open`/`fid_at_open`）取目标循环打开后（含自身）的深度：
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/// 当前深度与之差 = 被逃出的中间层数。目标循环自身的关闭由循环收尾指令
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/// （FOR_OF_CLOSE / FOR_IN_CLEANUP）处理，不计入——break 的跳转目标在收尾指令
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/// 之后（含其 CLOSE），continue 则目标循环继续迭代。
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fn escape_iter_counts(ctx: &CompileCtx, fod_at_open: usize, fid_at_open: usize) -> (usize, usize) {
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let for_of_count = ctx.labels.for_of_depth.saturating_sub(fod_at_open);
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let for_in_count = ctx.labels.for_in_depth.saturating_sub(fid_at_open);
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(for_of_count, for_in_count)
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}
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