From 30ff21e757a54224edf7e1aff5f956aa4376467a Mon Sep 17 00:00:00 2001
From: Michael Gottesman <mgottesman@apple.com>
Date: Tue, 24 Aug 2021 19:31:35 -0700
Subject: [PATCH] [silgen] Ensure that the outer cleanup is emitted along
 failure paths when initializing sub-tuple patterns

Previously, we would leak in this case along the inner failure path since we had
already forwarded the outer cleanup. Instead in this patch, I change the outer
cleanup to be persistently active (ensuring that failure paths along the
sub-pattern are cleaned up appropriately) and forward it manually afterwards
ensuring that we do not /actually/ emit the cleanup along the success path.

rdar://81817725
---
 lib/SILGen/SILGenDecl.cpp | 13 +++++++++++--
 test/SILGen/enum.swift    | 20 ++++++++++++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/lib/SILGen/SILGenDecl.cpp b/lib/SILGen/SILGenDecl.cpp
index 6943ec9201f69..c7d8e94ec2334 100644
--- a/lib/SILGen/SILGenDecl.cpp
+++ b/lib/SILGen/SILGenDecl.cpp
@@ -69,9 +69,16 @@ void TupleInitialization::copyOrInitValueInto(SILGenFunction &SGF,
   // In the address case, we forward the underlying value and store it
   // into memory and then create a +1 cleanup. since we assume here
   // that we have a +1 value since we are forwarding into memory.
+  //
+  // In order to ensure that we properly clean up along any failure paths, we
+  // need to mark value as being persistently active. We then unforward it once
+  // we are done.
   assert(value.isPlusOne(SGF) && "Can not store a +0 value into memory?!");
-  value = ManagedValue::forUnmanaged(value.forward(SGF));
-  return copyOrInitValueIntoHelper(
+  CleanupStateRestorationScope valueScope(SGF.Cleanups);
+  if (value.hasCleanup())
+    valueScope.pushCleanupState(value.getCleanup(),
+                                CleanupState::PersistentlyActive);
+  copyOrInitValueIntoHelper(
       SGF, loc, value, isInit, SubInitializations,
       [&](ManagedValue aggregate, unsigned i,
           SILType fieldType) -> ManagedValue {
@@ -83,6 +90,8 @@ void TupleInitialization::copyOrInitValueInto(SILGenFunction &SGF,
 
         return SGF.emitManagedRValueWithCleanup(elt.getValue());
       });
+  std::move(valueScope).pop();
+  value.forward(SGF);
 }
 
 void TupleInitialization::finishUninitialized(SILGenFunction &SGF) {
diff --git a/test/SILGen/enum.swift b/test/SILGen/enum.swift
index 00b1b21cada77..5a9ca073cdb66 100644
--- a/test/SILGen/enum.swift
+++ b/test/SILGen/enum.swift
@@ -219,3 +219,23 @@ func sr7799_1(bar: SR7799??) {
   default: print("default")
   }
 }
+
+// Make sure that we handle enum, tuple initialization composed
+// correctly. Previously, we leaked down a failure path due to us misusing
+// scopes.
+enum rdar81817725 {
+    case localAddress
+    case setOption(Int, Any)
+
+    static func takeAny(_:Any) -> Bool { return true }
+
+    static func testSwitchCleanup(syscall: rdar81817725, expectedLevel: Int,
+                                  valueMatcher: (Any) -> Bool)
+      throws -> Bool {
+        if case .setOption(expectedLevel, let value) = syscall {
+            return rdar81817725.takeAny(value)
+        } else {
+            return false
+        }
+    }
+}