From 264a295beda3853e845b538fb83c7c312a0eb7f0 Mon Sep 17 00:00:00 2001
From: Tom French <tom@tomfren.ch>
Date: Mon, 11 Sep 2023 18:54:20 +0100
Subject: [PATCH] fix: display correct range for `u128` in
 `OverflowingAssignment` error

---
 crates/noirc_frontend/src/hir/type_check/stmt.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/crates/noirc_frontend/src/hir/type_check/stmt.rs b/crates/noirc_frontend/src/hir/type_check/stmt.rs
index 0407f79049f..f997b048753 100644
--- a/crates/noirc_frontend/src/hir/type_check/stmt.rs
+++ b/crates/noirc_frontend/src/hir/type_check/stmt.rs
@@ -283,12 +283,14 @@ impl<'interner> TypeChecker<'interner> {
             HirExpression::Literal(HirLiteral::Integer(value)) => {
                 let v = value.to_u128();
                 if let Type::Integer(_, bit_count) = annotated_type {
-                    let max = 1 << bit_count;
+                    // Avoid overflow in bitshift
+                    let max: u128 =
+                        if *bit_count == 128 { u128::MAX } else { (1 << bit_count) - 1 };
                     if v >= max {
                         self.errors.push(TypeCheckError::OverflowingAssignment {
                             expr: value,
                             ty: annotated_type.clone(),
-                            range: format!("0..={}", max - 1),
+                            range: format!("0..={}", max),
                             span,
                         });
                     };