better error message

xdslproject · Feb 19, 2025 · b941802 · b941802
1 parent ecccb15
commit b941802
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Showing 2 changed files with 7 additions and 4 deletions.
diff --git a/tests/backend/test_register.py b/tests/backend/test_register.py
@@ -24,5 +24,8 @@ def infinite_register_prefix(cls):
 
 
 def test_register_clashes():
-    with pytest.raises(AssertionError, match="Invalid 'infinite' register name x"):
+    with pytest.raises(
+        AssertionError,
+        match="Invalid 'infinite' register name: x0 clashes with finite register set",
+    ):
         TestRegister.infinite_register(0)
diff --git a/xdsl/backend/register_type.py b/xdsl/backend/register_type.py
@@ -96,9 +96,9 @@ def infinite_register(cls, index: int) -> Self:
         """
         Provide the register at the given index in the "infinite" register set.
         """
-        spelling = cls.infinite_register_prefix()
-        res = cls(spelling + str(index))
+        spelling = cls.infinite_register_prefix() + str(index)
+        res = cls(spelling)
         assert isinstance(res.index, NoneAttr), (
-            f"Invalid 'infinite' register name {spelling}"
+            f"Invalid 'infinite' register name: {spelling} clashes with finite register set"
         )
         return res