From c8b8e25fbb6bde1eb8f59ba98338e2c2616c49b0 Mon Sep 17 00:00:00 2001
From: Owen Mansel-Chan <owen-mc@github.com>
Date: Mon, 5 May 2025 18:50:04 -0400
Subject: [PATCH] Convert post-update logic to IR (part 1)

---
 .../go/dataflow/internal/DataFlowNodes.qll       | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/go/ql/lib/semmle/go/dataflow/internal/DataFlowNodes.qll b/go/ql/lib/semmle/go/dataflow/internal/DataFlowNodes.qll
index 79026544d4d..cf93dd042f3 100644
--- a/go/ql/lib/semmle/go/dataflow/internal/DataFlowNodes.qll
+++ b/go/ql/lib/semmle/go/dataflow/internal/DataFlowNodes.qll
@@ -807,12 +807,18 @@ module Public {
     abstract Node getPreUpdateNode();
   }
 
+  predicate insnHasPostUpdateNode(IR::Instruction insn) {
+    exists(Expr e | insn.(IR::EvalInstruction).getExpr() = e |
+      e instanceof AddressExpr or
+      e = any(AddressExpr ae).getOperand() or
+      e = any(StarExpr ae).getBase() or
+      e = any(DerefExpr ae).getOperand() or
+      e = any(IR::EvalImplicitDerefInstruction eidi).getOperand()
+    )
+  }
+
   predicate hasPostUpdateNode(Node preupd) {
-    preupd instanceof AddressOperationNode
-    or
-    preupd = any(AddressOperationNode addr).getOperand()
-    or
-    preupd = any(PointerDereferenceNode deref).getOperand()
+    insnHasPostUpdateNode(preupd.asInstruction())
     or
     preupd = getAWrittenNode()
     or