core: fix (and test) operands/results directives with no variadics (#…

…3551)

Managed to miss the test for when there are no variadic/optional
operands or results. Turns out this functionality was broken.

tests/irdl/test_declarative_assembly_format.py

@@ -1014,8 +1014,8 @@ class TwoOperandsOp(IRDLOperation):
         "test.operands_directive %0, %1, %2 : i32, i32, i32",
     ],
 )
-def test_operands_directive(program: str):
-    """Test the operands directive"""
+def test_operands_directive_with_variadic(program: str):
+    """Test the operands directive with a variadic operand"""
 
     @irdl_op_definition
     class OperandsDirectiveOp(IRDLOperation):
@@ -1041,7 +1041,7 @@ class OperandsDirectiveOp(IRDLOperation):
     ],
 )
 def test_operands_directive_with_optional(program: str):
-    """Test the operands directive"""
+    """Test the operands directive with an optional operand"""
 
     @irdl_op_definition
     class OperandsDirectiveOp(IRDLOperation):
@@ -1059,6 +1059,25 @@ class OperandsDirectiveOp(IRDLOperation):
     check_roundtrip(program, ctx)
 
 
+def test_operands_directive_with_no_variadic():
+    """Test the operands directive with no variadic operands"""
+
+    @irdl_op_definition
+    class OperandsDirectiveOp(IRDLOperation):
+        name = "test.operands_directive"
+
+        op1 = operand_def()
+        op2 = operand_def()
+
+        assembly_format = "operands `:` type(operands) attr-dict"
+
+    ctx = MLContext()
+    ctx.load_op(OperandsDirectiveOp)
+    ctx.load_dialect(Test)
+
+    check_roundtrip("test.operands_directive %0, %1 : i32, i32", ctx)
+
+
 def test_operands_directive_fails_with_two_var():
     """Test operands directive cannot be used with two variadic operands"""
 
@@ -1393,8 +1412,8 @@ class OptionalResultOp(IRDLOperation):
         "%0, %1, %2 = test.results_directive : i32, i32, i32",
     ],
 )
-def test_results_directive(program: str):
-    """Test the results directive"""
+def test_results_directive_with_variadic(program: str):
+    """Test the results directive with a variadic result"""
 
     @irdl_op_definition
     class ResultsDirectiveOp(IRDLOperation):
@@ -1438,6 +1457,25 @@ class ResultsDirectiveOp(IRDLOperation):
     check_roundtrip(program, ctx)
 
 
+def test_results_directive_with_no_variadic():
+    """Test the results directive with no variadic results"""
+
+    @irdl_op_definition
+    class ResultsDirectiveOp(IRDLOperation):
+        name = "test.results_directive"
+
+        res1 = result_def()
+        res2 = result_def()
+
+        assembly_format = "attr-dict `:` type(results)"
+
+    ctx = MLContext()
+    ctx.load_op(ResultsDirectiveOp)
+    ctx.load_dialect(Test)
+
+    check_roundtrip("%0, %1 = test.results_directive : i32, i32", ctx)
+
+
 def test_results_directive_fails_with_two_var():
     """Test results directive cannot be used with two variadic results"""
 

xdsl/irdl/declarative_assembly_format.py

@@ -629,7 +629,7 @@ def _set_using_variadic_index(
         if self.variadic_index is None:
             if len(set_to) != len(field):
                 return f"Expected {len(field)} {field_name} but found {len(set_to)}"
-            field = [o for o in set_to]  # Copy needed as list is not covariant
+            field[:] = set_to
             return
 
         is_optional, var_position = self.variadic_index