From fcf3bdcac8ccf6f6f68759ebd9d643eab4d1625e Mon Sep 17 00:00:00 2001
From: Taeer Bar-Yam <taeer@bar-yam.me>
Date: Mon, 10 Nov 2025 20:42:28 +0100
Subject: [PATCH] move ExprAttrs data into Exprs::alloc

---
 src/libexpr/nixexpr.cc | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc
index 2bf77c477..3de5bdcb8 100644
--- a/src/libexpr/nixexpr.cc
+++ b/src/libexpr/nixexpr.cc
@@ -401,6 +401,17 @@ ExprAttrs::bindInheritSources(EvalState & es, const std::shared_ptr<const Static
 
 void ExprAttrs::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
 {
+    // Move storage into the Exprs arena
+    {
+        auto arena = es.mem.exprs.alloc;
+        AttrDefs newAttrs{std::move(*attrs), arena};
+        attrs.emplace(std::move(newAttrs), arena);
+        DynamicAttrDefs newDynamicAttrs{std::move(*dynamicAttrs), arena};
+        dynamicAttrs.emplace(std::move(newDynamicAttrs), arena);
+        if (inheritFromExprs)
+            inheritFromExprs = std::make_unique<std::pmr::vector<Expr *>>(std::move(*inheritFromExprs), arena);
+    }
+
     if (es.debugRepl)
         es.exprEnvs.insert(std::make_pair(this, env));