From 1527d68566d82a6d22f57105d7e141aab519d069 Mon Sep 17 00:00:00 2001
From: Stevengre <zhaojianhong96@gmail.com>
Date: Mon, 10 Nov 2025 12:41:21 +0800
Subject: [PATCH] fix(rt): add fallback for zero-sized constants in operand
 decoding

---
 kmir/src/kmir/kdist/mir-semantics/rt/data.md | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/kmir/src/kmir/kdist/mir-semantics/rt/data.md b/kmir/src/kmir/kdist/mir-semantics/rt/data.md
index 087af074d..6d273684d 100644
--- a/kmir/src/kmir/kdist/mir-semantics/rt/data.md
+++ b/kmir/src/kmir/kdist/mir-semantics/rt/data.md
@@ -128,6 +128,13 @@ Constant operands are simply decoded according to their type.
        ...
        </k>
     requires typeInfoVoidType =/=K lookupTy(TY)
+
+  // Fallback for zero-sized constants whose type metadata was not emitted.
+  rule <k> operandConstant(constOperand(_, _, mirConst(constantKindZeroSized, TY, _)))
+        => Aggregate(variantIdx(0), .List)
+       ...
+       </k>
+    requires typeInfoVoidType ==K lookupTy(TY) 
 ```
 
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