From 0923c044683aead45384f083fb1ac146a3a0c31a Mon Sep 17 00:00:00 2001
From: Mykola Pokhylets <mykola.pokhylets@gmail.com>
Date: Sun, 16 Mar 2025 16:13:18 +0100
Subject: [PATCH] [WIP] Fix https://github.com/swiftlang/swift/issues/80014

---
 lib/SIL/IR/SILType.cpp                        |  7 ++++++-
 lib/SILOptimizer/Analysis/RegionAnalysis.cpp  |  4 +++-
 .../sending_mutable_captures.swift            | 20 +++++++++++++++++++
 3 files changed, 29 insertions(+), 2 deletions(-)
 create mode 100644 test/Concurrency/sending_mutable_captures.swift

diff --git a/lib/SIL/IR/SILType.cpp b/lib/SIL/IR/SILType.cpp
index 78f027f3ede9b..551ff2a6584ac 100644
--- a/lib/SIL/IR/SILType.cpp
+++ b/lib/SIL/IR/SILType.cpp
@@ -1247,7 +1247,12 @@ SILType SILType::removingAnyMoveOnlyWrapping(const SILFunction *fn) {
 }
 
 bool SILType::isSendable(SILFunction *fn) const {
-  return getASTType()->isSendableType();
+  switch (getCategory()) {
+  case SILValueCategory::Object:
+    return getASTType()->isSendableType();
+  case SILValueCategory::Address:
+    return false;
+  }
 }
 
 Type SILType::getRawLayoutSubstitutedLikeType() const {
diff --git a/lib/SILOptimizer/Analysis/RegionAnalysis.cpp b/lib/SILOptimizer/Analysis/RegionAnalysis.cpp
index ac959e18f6733..70b7d2b9d1f85 100644
--- a/lib/SILOptimizer/Analysis/RegionAnalysis.cpp
+++ b/lib/SILOptimizer/Analysis/RegionAnalysis.cpp
@@ -2539,11 +2539,13 @@ class PartitionOpTranslator {
     auto trackableDest = tryToTrackValue(dest);
     if (!trackableDest)
       return;
+    if (requireOperands) {
+      builder.addRequire(trackableDest->getRepresentative().getValue());
+    }
     for (Operand *op : srcCollection) {
       if (auto trackableSrc = tryToTrackValue(op->get())) {
         if (requireOperands) {
           builder.addRequire(trackableSrc->getRepresentative().getValue());
-          builder.addRequire(trackableDest->getRepresentative().getValue());
         }
         builder.addMerge(trackableDest->getRepresentative().getValue(), op);
       }
diff --git a/test/Concurrency/sending_mutable_captures.swift b/test/Concurrency/sending_mutable_captures.swift
new file mode 100644
index 0000000000000..3b5b144619485
--- /dev/null
+++ b/test/Concurrency/sending_mutable_captures.swift
@@ -0,0 +1,20 @@
+// RUN: %target-swift-frontend -emit-sil -swift-version 6 %s -o /dev/null -verify
+
+func foo() {
+  var x: X? = X()
+  // expected-error@+2{{sending value of non-Sendable type '() -> Void' risks causing data races}}
+  // expected-note@+1{{Passing value of non-Sendable type '() -> Void' as a 'sending' argument to global function 'user' risks causing races in between local and caller code}}
+  user {
+    x?.bar()
+    x = nil
+  }
+  x = nil // expected-note{{access can happen concurrently}}
+}
+
+func user(_ block: sending @escaping @isolated(any) () -> Void) {
+
+}
+
+final class X: Sendable {
+  func bar() {}
+}