From 6cdfb160999a048d2e933c1296ac01c0762ea44f Mon Sep 17 00:00:00 2001
From: Sasha Lopoukhine <superlopuh@gmail.com>
Date: Wed, 29 Jan 2025 11:42:29 +0100
Subject: [PATCH] dialects: (builtin) integer bitwidths must not be negative
 (#3799)

---
 tests/dialects/test_builtin.py | 6 ++++++
 xdsl/dialects/builtin.py       | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/tests/dialects/test_builtin.py b/tests/dialects/test_builtin.py
index 30c0f2ab37..0012e71f62 100644
--- a/tests/dialects/test_builtin.py
+++ b/tests/dialects/test_builtin.py
@@ -72,6 +72,12 @@ def test_FloatType_formats():
         Float128Type().format
 
 
+def test_IntegerType_verifier():
+    IntegerType(32)
+    with pytest.raises(VerifyException):
+        IntegerType(-1)
+
+
 def test_IntegerType_formats():
     assert IntegerType(1).format == "<b"
     assert IntegerType(2).format == "<b"
diff --git a/xdsl/dialects/builtin.py b/xdsl/dialects/builtin.py
index 493978021e..9144251cc2 100644
--- a/xdsl/dialects/builtin.py
+++ b/xdsl/dialects/builtin.py
@@ -478,6 +478,12 @@ def __init__(
             signedness = SignednessAttr(signedness)
         super().__init__([data, signedness])
 
+    def verify(self):
+        if self.width.data < 0:
+            raise VerifyException(
+                f"integer type bitwidth should be nonnegative (got {self.width.data})"
+            )
+
     def value_range(self) -> tuple[int, int]:
         return self.signedness.data.value_range(self.width.data)