Fix array unpacking case

guppylang/checker/core.py

@@ -175,7 +175,8 @@ class SubscriptAccess:
     ty: Type
     item_expr: ast.expr
     getitem_call: ast.expr | None = None
-    setitem_call: ast.expr | None = None
+    # Store a temp variable for the RHS of an assignment so it can be assigned a port.
+    setitem_call: tuple[ast.expr, ast.expr] | None = None
 
     @dataclass(frozen=True)
     class Id:

guppylang/checker/expr_checker.py

@@ -923,6 +923,7 @@ def check_inout_arg_place(place: Place, ctx: Context, node: PlaceNode) -> Place:
             return replace(place, parent=check_inout_arg_place(parent, ctx, node))
         case SubscriptAccess(parent=parent, item=item, ty=ty):
             # Check a call to the `__setitem__` instance function
+            rhs = with_type(ty, with_loc(node, InoutReturnSentinel(var=place)))
             exp_sig = FunctionType(
                 [
                     FuncInput(parent.ty, InputFlags.Inout),
@@ -934,7 +935,7 @@ def check_inout_arg_place(place: Place, ctx: Context, node: PlaceNode) -> Place:
             setitem_args = [
                 with_type(parent.ty, with_loc(node, PlaceNode(parent))),
                 with_type(item.ty, with_loc(node, PlaceNode(item))),
-                with_type(ty, with_loc(node, InoutReturnSentinel(var=place))),
+                rhs,
             ]
             setitem_call, _ = ExprSynthesizer(ctx).synthesize_instance_func(
                 setitem_args[0],
@@ -944,7 +945,7 @@ def check_inout_arg_place(place: Place, ctx: Context, node: PlaceNode) -> Place:
                 exp_sig,
                 True,
             )
-            return replace(place, setitem_call=setitem_call)
+            return replace(place, setitem_call=(setitem_call, rhs))
 
 
 def synthesize_call(

guppylang/checker/linearity_checker.py

@@ -332,7 +332,7 @@ def _reassign_single_inout_arg(self, place: Place, node: AstNode) -> None:
         # Places involving subscripts are given back by visiting the `__setitem__` call
         if subscript := contains_subscript(place):
             assert subscript.setitem_call is not None
-            self.visit(subscript.setitem_call)
+            self.visit(subscript.setitem_call[0])
             self._reassign_single_inout_arg(subscript.parent, node)
         else:
             for leaf in leaf_places(place):

guppylang/checker/stmt_checker.py

@@ -196,6 +196,9 @@ def _check_subscript_assign(
         item_expr, item_ty = self._synth_expr(lhs.slice)
         item = Variable(next(tmp_vars), item_ty, item_expr)
 
+        # Create and store a temp variable to ensure RHS has a wire during compilation.
+        tmp_rhs = self._check_assign(make_var(next(tmp_vars), rhs), rhs, rhs_ty)
+
         parent = value.place
 
         exp_set_sig = FunctionType(
@@ -209,7 +212,7 @@ def _check_subscript_assign(
         setitem_args = [
             with_type(parent.ty, with_loc(lhs, PlaceNode(parent))),
             with_type(item.ty, with_loc(lhs, PlaceNode(item))),
-            rhs,
+            tmp_rhs,
         ]
         setitem_call, _ = self._synth_instance_fun(
             setitem_args[0],
@@ -221,7 +224,7 @@ def _check_subscript_assign(
         )
 
         place = SubscriptAccess(
-            parent, item, rhs_ty, item_expr, setitem_call=setitem_call
+            parent, item, rhs_ty, item_expr, setitem_call=(setitem_call, tmp_rhs)
         )
         return with_loc(lhs, with_type(rhs_ty, PlaceNode(place=place)))
 

guppylang/compiler/expr_compiler.py

@@ -282,7 +282,8 @@ def _update_inout_ports(
                 # `arg.place.parent` occurs as an arg of this call, so will also
                 # be recursively reassigned.
                 if subscript := contains_subscript(arg.place):
-                    self.visit(subscript.setitem_call)
+                    assert subscript.setitem_call is not None
+                    self.visit(subscript.setitem_call[0])
         assert next(inout_ports, None) is None, "Too many inout return ports"
 
     def visit_LocalCall(self, node: LocalCall) -> Wire:

guppylang/compiler/stmt_compiler.py

@@ -72,7 +72,6 @@ def _assign(self, lhs: ast.expr, port: Wire) -> None:
 
     @_assign.register
     def _assign_place(self, lhs: PlaceNode, port: Wire) -> None:
-        self.dfg[lhs.place] = port
         if (subscript := contains_subscript(lhs.place)) and isinstance(
             lhs.place, SubscriptAccess
         ):
@@ -81,7 +80,10 @@ def _assign_place(self, lhs: PlaceNode, port: Wire) -> None:
                 self.dfg[subscript.item] = self.expr_compiler.compile(
                     subscript.item_expr, self.dfg
                 )
-            self.expr_compiler.visit(subscript.setitem_call)
+            self._assign(subscript.setitem_call[1], port)
+            self.expr_compiler.visit(subscript.setitem_call[0])
+        else:
+            self.dfg[lhs.place] = port
 
     @_assign.register
     def _assign_tuple(self, lhs: TupleUnpack, port: Wire) -> None:

tests/integration/test_array.py

@@ -526,7 +526,6 @@ def main() -> int:
     run_int_fn(compiled, expected=5)
 
 
-@pytest.mark.skip("TODO: Fix this")
 def test_subscript_assign_unpacking_range(validate, run_int_fn):
     module = GuppyModule("test")
 
@@ -538,10 +537,9 @@ def main() -> int:
 
     compiled = module.compile()
     validate(compiled)
-    run_int_fn(compiled, expected=4)
+    run_int_fn(compiled, expected=9)
 
 
-@pytest.mark.skip("TODO: Fix this")
 def test_subscript_assign_unpacking_array(validate, run_int_fn):
     module = GuppyModule("test")