feat(coro): M5——协程内 try/except 捕获（raise 与 await 传播异常）

- _HandleCoroTry：except_bb/merge_bb 控制流，单 except 捕获所有异常 - 协程内 raise 与 await 子协程异常传播：处于 try 栈内时改跳 except 处理器，栈外维持原终止语义（done=1 + br exit） - except X as e：异常码绑定到 e（帧槽），捕获后清帧 exc - 预扫描/_CollectFrameVars 递归 Try（handler.name 进帧槽，跨挂起存活） - CoroTest 验证：try 捕获 await 传播异常 → coro result = 42, exc = 0
2026-08-21 14:28:52 +08:00
1 parent 411e0bb774
commit 69447025a7
@@ -96,6 +96,7 @@ class AsyncFunctionHandle(BaseHandle):
            'for_counter': getattr(Gen, '_coro_for_counter', None),
            'wake_ptr': getattr(Gen, '_coro_wake_ptr', None),
            'exc_ptr': getattr(Gen, '_coro_exc_ptr', None),
+            'try_stack': getattr(Gen, '_coro_try_stack', None),
        }
        try:
            self.Trans.VarScopes.append({})
@@ -139,6 +140,7 @@ class AsyncFunctionHandle(BaseHandle):
            Gen._coro_for_counter = saved_coro_state['for_counter']
            Gen._coro_wake_ptr = saved_coro_state['wake_ptr']
            Gen._coro_exc_ptr = saved_coro_state['exc_ptr']
+            Gen._coro_try_stack = saved_coro_state['try_stack']

    # ------------------------------------------------------------------
    # 帧结构体与局部变量收集
@@ -195,6 +197,20 @@ class AsyncFunctionHandle(BaseHandle):
                    if stmt.orelse:
                        _walk(stmt.orelse)
                    continue
+                elif isinstance(stmt, ast.Try):
+                    # except X as e：e 进帧槽（异常码）
+                    for _h in stmt.handlers:
+                        if _h.name and _h.name not in seen:
+                            seen.add(_h.name)
+                            vars_.append((_h.name, ir.IntType(32)))
+                    _walk(stmt.body)
+                    for _h in stmt.handlers:
+                        _walk(_h.body)
+                    if stmt.orelse:
+                        _walk(stmt.orelse)
+                    if stmt.finalbody:
+                        _walk(stmt.finalbody)
+                    continue
                else:
                    continue
                if target not in seen:
@@ -271,6 +287,15 @@ class AsyncFunctionHandle(BaseHandle):
                    if stmt.orelse:
                        _walk(stmt.orelse)
                    continue
+                if isinstance(stmt, ast.Try):
+                    _walk(stmt.body)
+                    for _h in stmt.handlers:
+                        _walk(_h.body)
+                    if stmt.orelse:
+                        _walk(stmt.orelse)
+                    if stmt.finalbody:
+                        _walk(stmt.finalbody)
+                    continue
                if isinstance(stmt, ast.For):
                    if not any(isinstance(n, ast.Await) for n in ast.walk(stmt)):
                        continue  # 无 await：委托 ForHandler，不需额外槽
@@ -449,6 +474,9 @@ class AsyncFunctionHandle(BaseHandle):
            if isinstance(stmt, ast.While):
                self._HandleCoroWhile(stmt, Gen)
                continue
+            if isinstance(stmt, ast.Try):
+                self._HandleCoroTry(stmt, Gen)
+                continue
            if isinstance(stmt, ast.For):
                self._HandleCoroFor(stmt, Gen)
                continue
@@ -678,6 +706,10 @@ class AsyncFunctionHandle(BaseHandle):
        exc_ptr: ir.Value | None = getattr(Gen, '_coro_exc_ptr', None)
        if exc_ptr is not None:
            Gen._store(exc_code, exc_ptr)
+        coro_try_stack: list[ir.Block] | None = getattr(Gen, '_coro_try_stack', None)
+        if coro_try_stack:
+            Gen.builder.branch(coro_try_stack[-1])
+            return
        done_ptr_r: ir.Value | None = getattr(Gen, '_coro_done_ptr', None)
        if done_ptr_r is not None:
            Gen._store(ir.Constant(ir.IntType(32), 1), done_ptr_r)
@@ -783,12 +815,16 @@ class AsyncFunctionHandle(BaseHandle):
        parent_exc_ptr: ir.Value | None = getattr(Gen, '_coro_exc_ptr', None)
        if parent_exc_ptr is not None:
            Gen._store(child_exc, parent_exc_ptr)
-        parent_done_ptr: ir.Value | None = getattr(Gen, '_coro_done_ptr', None)
-        if parent_done_ptr is not None:
-            Gen._store(ir.Constant(ir.IntType(32), 1), parent_done_ptr)
-        exit_bb_ref: ir.Block | None = getattr(Gen, '_coro_exit_bb', None)
-        if exit_bb_ref is not None:
-            Gen.builder.branch(exit_bb_ref)
+        coro_try: list[ir.Block] | None = getattr(Gen, '_coro_try_stack', None)
+        if coro_try:
+            Gen.builder.branch(coro_try[-1])
+        else:
+            parent_done_ptr: ir.Value | None = getattr(Gen, '_coro_done_ptr', None)
+            if parent_done_ptr is not None:
+                Gen._store(ir.Constant(ir.IntType(32), 1), parent_done_ptr)
+            exit_bb_ref: ir.Block | None = getattr(Gen, '_coro_exit_bb', None)
+            if exit_bb_ref is not None:
+                Gen.builder.branch(exit_bb_ref)
        # 正常路径：存父帧局部变量槽 + 挂起
        Gen.builder.position_at_start(normal_bb)
        slot: ir.Value | None = getattr(Gen, '_coro_await_slot_ptr', None)
@@ -918,6 +954,51 @@ class AsyncFunctionHandle(BaseHandle):
        else:
            Gen.builder.position_at_end(AfterBB)

+    def _HandleCoroTry(self, Node: ast.Try, Gen: LlvmCodeGenerator) -> None:
+        """协程内 try/except：捕获 raise 与 await 传播的异常（M5：单 except、捕获所有）。"""
+        if not Node.handlers:
+            raise SyntaxError(
+                f"[coro-M5] 协程内 try 需要 except 子句 (line {getattr(Node, 'lineno', 0)})"
+            )
+        if len(Node.handlers) > 1:
+            raise SyntaxError(
+                f"[coro-M5] 协程内仅支持单个 except（多 except 留待扩展）"
+                f"(line {getattr(Node, 'lineno', 0)})"
+            )
+        if Node.finalbody:
+            raise SyntaxError(
+                f"[coro-M5] 协程内暂不支持 try/finally (line {getattr(Node, 'lineno', 0)})"
+            )
+        except_bb: ir.Block = Gen.func.append_basic_block('coro_try_except')
+        merge_bb: ir.Block = Gen.func.append_basic_block('coro_try_merge')
+        if not getattr(Gen, '_coro_try_stack', None):
+            Gen._coro_try_stack = []
+        Gen._coro_try_stack.append(except_bb)
+        # try body
+        self._HandleCoroSegment(Node.body, Gen)
+        if Gen.builder is not None and not Gen.builder.block.is_terminated:
+            Gen.builder.branch(merge_bb)
+        Gen._coro_try_stack.pop()
+        # except handler：异常码已在帧 exc 槽，绑定到 handler.name 后清异常
+        Gen.builder.position_at_start(except_bb)
+        handler: Any = Node.handlers[0]
+        exc_ptr: ir.Value | None = getattr(Gen, '_coro_exc_ptr', None)
+        if handler.name:
+            e_slot: ir.Value | None = Gen.variables.get(handler.name)
+            if e_slot is not None and exc_ptr is not None:
+                exc_val: ir.Value = Gen._load(exc_ptr, name='coro_exc_val')
+                Gen._store(exc_val, e_slot)
+            Gen._record_var_signedness(handler.name, False)
+        if exc_ptr is not None:
+            Gen._store(ir.Constant(ir.IntType(32), 0), exc_ptr)
+        self._HandleCoroSegment(handler.body, Gen)
+        if Gen.builder is not None and not Gen.builder.block.is_terminated:
+            Gen.builder.branch(merge_bb)
+        if not merge_bb.is_terminated:
+            Gen.builder.position_at_start(merge_bb)
+        else:
+            Gen.builder.position_at_end(merge_bb)
+
    def _HandleCoroFor(self, Node: ast.For, Gen: LlvmCodeGenerator) -> None:
        if any(isinstance(n, ast.Await) for n in ast.walk(Node)):
            if not self._IsRangeFor(Node):