fixing bug with multi-return values in statement (#358)

Author: weinbe58

src/kirin/analysis/const/prop.py

@@ -67,7 +67,7 @@ def try_eval_const_pure(
         if method is not None:
             value = method(self._interp, _frame, stmt)
         else:
-            return (Unknown(),)
+            return tuple(Unknown() for _ in stmt.results)
         match value:
             case tuple():
                 return tuple(Value(each) for each in value)

test/analysis/dataflow/constprop/__init__.py

@@ -0,0 +1,57 @@
+from kirin import ir, types, lowering
+from kirin.decl import info, statement
+from kirin.passes import Fold, TypeInfer
+from kirin.prelude import structural_no_opt
+from kirin.analysis import const
+from kirin.dialects import py, func, ilist
+
+dialect = ir.Dialect("analysis")
+
+
+@statement(dialect=dialect)
+class MultiReturnStatement(ir.Statement):
+    traits = frozenset({lowering.FromPythonCall(), ir.Pure()})
+    inputs: tuple[ir.SSAValue] = info.argument(types.Any)
+
+    def __init__(self, *args: ir.SSAValue):
+        super().__init__(
+            args=args,
+            result_types=tuple(arg.type for arg in args),
+            args_slice={"inputs": slice(None)},
+        )
+
+
+@ir.dialect_group(structural_no_opt.add(dialect))
+def dialect_group_test(self):
+    fold = Fold(self)
+    type_infer = TypeInfer(self)
+
+    def run_pass(mt):
+        type_infer(mt)
+        fold(mt)
+
+    return run_pass
+
+
+def test_multi_return_default_prop():
+
+    stmts = [
+        (a := py.Constant(1)),
+        (b := py.Constant(2)),
+        (res := MultiReturnStatement(a.result, b.result)),
+        (return_result := ilist.New((res.results[0], res.results[1]))),
+        (func.Return(return_result.result)),
+    ]
+
+    body = ir.Region(ir.Block(stmts))
+    func_code = func.Function(
+        sym_name="test", signature=func.Signature((), types.Any), body=body
+    )
+    mt = ir.Method(None, None, "test", (), dialect_group_test, func_code)
+
+    frame, return_result = const.Propagate(dialect_group_test).run_analysis(
+        mt, no_raise=False
+    )
+
+    assert frame.entries[res.results[0]] == const.Unknown()
+    assert frame.entries[res.results[1]] == const.Unknown()