From 990f5d95ec26b947c0adced8b9c6f5cb83516173 Mon Sep 17 00:00:00 2001
From: Meghana Gupta <meghanavgupta@gmail.com>
Date: Fri, 31 Jan 2025 15:03:01 -0800
Subject: [PATCH] Fix swift::areUsesWithinValueLifetime for guaranteed values

To find if all the uses are within a guaranteed value, we should find all borrow introducers.

swift::findOwnershipReferenceAggregate looks only through forwarding operations with single operands.

For simplicity, continue using swift::findOwnershipReferenceAggregate, but return false when it does
not find a borrow introducer.
---
 lib/SILOptimizer/Utils/OwnershipOptUtils.cpp |  7 ++++++
 test/SILOptimizer/outliner_ossa.sil          | 25 ++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/lib/SILOptimizer/Utils/OwnershipOptUtils.cpp b/lib/SILOptimizer/Utils/OwnershipOptUtils.cpp
index 850533fec9148..f3d5308eddcde 100644
--- a/lib/SILOptimizer/Utils/OwnershipOptUtils.cpp
+++ b/lib/SILOptimizer/Utils/OwnershipOptUtils.cpp
@@ -468,8 +468,15 @@ bool swift::areUsesWithinValueLifetime(SILValue value, ArrayRef<Operand *> uses,
     return false;
   }
   if (value->getOwnershipKind() == OwnershipKind::Guaranteed) {
+    // For guaranteed values, we have to find the borrow introducing guaranteed
+    // reference roots and then ensure uses are within all of their lifetimes.
+    // For simplicity, we only look through single forwarding operations to find
+    // a borrow introducer here.
     value = findOwnershipReferenceAggregate(value);
     BorrowedValue borrowedValue(value);
+    if (!borrowedValue) {
+      return false;
+    }
     if (!borrowedValue.isLocalScope()) {
       return true;
     }
diff --git a/test/SILOptimizer/outliner_ossa.sil b/test/SILOptimizer/outliner_ossa.sil
index 7e2598530d8e6..78f66e9f9ec33 100644
--- a/test/SILOptimizer/outliner_ossa.sil
+++ b/test/SILOptimizer/outliner_ossa.sil
@@ -16,6 +16,7 @@ import Foundation
 
 struct DataWrapper {
   let data: Data
+  let otherData: Data
 }
 
 sil @getData : $@convention(thin) () -> @owned Data
@@ -200,6 +201,30 @@ bb0(%0: @owned $MyObject):
   return %51 : $Optional<NSData>
 }
 
+// Not optimized
+// CHECK-LABEL: sil [Osize] [ossa] @test_struct_guaranteed :
+// CHECK: objc_method
+// CHECK-LABEL: } // end sil function 'test_struct_guaranteed'
+sil [Osize] [ossa] @test_struct_guaranteed : $@convention(thin) (@owned MyObject) -> @owned Optional<NSData> {
+bb0(%0 : @owned $MyObject):
+  %1 = metatype $@objc_metatype MyObject.Type
+  %2 = function_ref @getData : $@convention(thin) () -> @owned Data
+  %3 = apply %2() : $@convention(thin) () -> @owned Data
+  %4 = begin_borrow %3
+  %5 = struct $DataWrapper (%4, %4)
+  %6 = struct_extract %5, #DataWrapper.data
+  %7 = function_ref @$s10Foundation4DataV19_bridgeToObjectiveCSo6NSDataCyF : $@convention(method) (@guaranteed Data) -> @owned NSData
+  %8 = apply %7(%6) : $@convention(method) (@guaranteed Data) -> @owned NSData
+  %9 = enum $Optional<NSData>, #Optional.some!enumelt, %8
+  end_borrow %4
+  %13 = objc_method %1, #MyObject.take!foreign : (MyObject.Type) -> (Data?) -> Data?, $@convention(objc_method) (Optional<NSData>, @objc_metatype MyObject.Type) -> @autoreleased Optional<NSData>
+  %14 = apply %13(%9, %1) : $@convention(objc_method) (Optional<NSData>, @objc_metatype MyObject.Type) -> @autoreleased Optional<NSData>
+  destroy_value %0
+  destroy_value %3
+  destroy_value %9
+  return %14
+}
+
 sil [Osize] [ossa] @test_dont_crash : $@convention(thin) (@owned MyObject) -> () {
 bb0(%0: @owned $MyObject):
   %35 = metatype $@objc_metatype MyObject.Type