From f39e43e5d09eb92e5e86c3104960c0971f707400 Mon Sep 17 00:00:00 2001
From: Sauyon Lee <sauyon@github.com>
Date: Tue, 17 Aug 2021 09:28:11 -0700
Subject: [PATCH] Allow conversions to an array to panic

---
 ql/src/semmle/go/controlflow/ControlFlowGraphImpl.qll | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/ql/src/semmle/go/controlflow/ControlFlowGraphImpl.qll b/ql/src/semmle/go/controlflow/ControlFlowGraphImpl.qll
index 341f92925db..5642a853513 100644
--- a/ql/src/semmle/go/controlflow/ControlFlowGraphImpl.qll
+++ b/ql/src/semmle/go/controlflow/ControlFlowGraphImpl.qll
@@ -1184,6 +1184,14 @@ module CFG {
   }
 
   private class ConversionExprTree extends PostOrderTree, ConversionExpr {
+    override Completion getCompletion() {
+      // conversions of a slice to an array pointer are the only kind that may panic
+      this.getType().(PointerType).getBaseType() instanceof ArrayType and
+      result = Panic()
+      or
+      result = Done()
+    }
+
     override ControlFlow::Node getNode() { result = MkExprNode(this) }
 
     override ControlFlowTree getChildTree(int i) { i = 0 and result = getOperand() }