From: Skgland <bennet.blessmann+github@googlemail.com>
Date: Sun, 7 Dec 2025 20:31:24 +0000 (+0100)
Subject: use checked multiplication in heap_index! macro
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=d63b0a192c25f9dd33902b8577fc813fea77efec;p=scryer-prolog.git

use checked multiplication in heap_index! macro
---

diff --git a/src/macros.rs b/src/macros.rs
index 2eda4980..4ac590eb 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -471,11 +471,16 @@ macro_rules! resource_error_call_result {
 }
 
 macro_rules! heap_index {
-    ($idx:expr) => {
+    ($idx:expr) => {{
+        let idx = $idx;
         std::mem::size_of::<HeapCellValue>()
-            .checked_mul($idx)
-            .unwrap()
-    };
+            .checked_mul(idx)
+            .expect(&format!(
+                "overflow while calculating heap index {idx} * {} > {}",
+                std::mem::size_of::<HeapCellValue>(),
+                usize::MAX,
+            ))
+    }};
 }
 
 macro_rules! cell_index {