爱特每羊队
103 lines
3.7 KiB
Rust
103 lines
3.7 KiB
Rust
//! Pass 3：异常边。
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//!
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//! 块内扫 TRY_BEGIN / TRY_FINALLY_BEGIN（块内标记，非 terminator），
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//! 从所在 BB 连 Exception 边到处理入口（仅起始 BB，不扩散）。
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use oxide_bytecode::opcode::OpCode;
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use oxide_ir::operand::Operand;
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use oxide_ir::IRFunction;
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use crate::{BasicBlock, EdgeKind};
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/// 补异常边：从 TRY 标记所在 BB 出发，指向处理入口块。
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pub(super) fn add_exception_edges(f: &IRFunction, blocks: &mut [BasicBlock]) {
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for i in 0..blocks.len() {
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let range = blocks[i].inst_range.clone();
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for inst_idx in range.start..range.end {
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let inst = &f.insts[inst_idx];
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if !matches!(inst.op, OpCode::TRY_BEGIN | OpCode::TRY_FINALLY_BEGIN) {
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continue;
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}
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if let Operand::Label(l) = inst.b {
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match f.label_pos.get(l as usize).and_then(|p| *p) {
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Some(p) => {
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let target = crate::split::block_id_of(p, blocks);
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// push 前去重：块内多个 TRY 标记可指向同一目标，只保留一条边。
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if !blocks[i].succs.contains(&(target, EdgeKind::Exception)) {
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blocks[i].succs.push((target, EdgeKind::Exception));
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}
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}
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None => debug_assert!(false, "unresolved label {l}"),
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}
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}
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}
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use crate::BasicBlock;
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use oxide_ir::inst::Inst;
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/// TRY_BEGIN 所在 BB 出发 Exception 边 → catch 入口块（仅起始 BB）。
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#[test]
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fn try_begin_emits_exception_edge_to_handler() {
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let mut f = IRFunction::new();
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f.insts.push(Inst::try_begin(0)); // 0: TRY_BEGIN → catch（label 0 → inst 2）
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f.insts
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.push(Inst::new(OpCode::NOP, Operand::None, Operand::None, Operand::None)); // 1
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f.insts
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.push(Inst::new(OpCode::NOP, Operand::None, Operand::None, Operand::None)); // 2: catch 入口
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f.label_pos = vec![Some(2)];
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f.label_count = 1;
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let mut blocks = vec![
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BasicBlock {
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inst_range: 0..2,
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preds: Vec::new(),
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succs: Vec::new(),
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},
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BasicBlock {
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inst_range: 2..3,
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preds: Vec::new(),
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succs: Vec::new(),
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},
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];
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add_exception_edges(&f, &mut blocks);
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assert_eq!(blocks[0].succs, vec![(1, EdgeKind::Exception)], "TRY_BEGIN 所在 BB 出 Exception 边");
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assert!(blocks[1].succs.is_empty(), "catch 入口块无出边");
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}
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/// 块内多个 TRY 标记指向同一目标：Exception 边去重。
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#[test]
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fn duplicate_exception_targets_deduplicated() {
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let mut f = IRFunction::new();
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f.insts.push(Inst::try_begin(0)); // 0: TRY_BEGIN → L0
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f.insts.push(Inst::try_finally_begin(0)); // 1: TRY_FINALLY_BEGIN → 同一 L0
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f.insts
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.push(Inst::new(OpCode::NOP, Operand::None, Operand::None, Operand::None)); // 2: L0 目标
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f.label_pos = vec![Some(2)];
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f.label_count = 1;
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let mut blocks = vec![
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BasicBlock {
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inst_range: 0..2,
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preds: Vec::new(),
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succs: Vec::new(),
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},
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BasicBlock {
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inst_range: 2..3,
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preds: Vec::new(),
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succs: Vec::new(),
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},
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];
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add_exception_edges(&f, &mut blocks);
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assert_eq!(
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blocks[0].succs,
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vec![(1, EdgeKind::Exception)],
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"两个 TRY 标记指向同一目标只保留一条 Exception 边"
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);
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}
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}
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