From a0c06f2304ea633572e23651c532aabc4c1b657e Mon Sep 17 00:00:00 2001
From: Guillaume Lessard <guillaume.lessard@apple.com>
Date: Wed, 19 Nov 2025 12:57:30 -0800
Subject: [PATCH 1/2] Revert "Use updated spelling for lifetime annotations.
 (#1584)"

This reverts commit 709808e15435036c64bb9535c061a041916e90cd.
---
 Package.swift                                | 2 +-
 Sources/FoundationEssentials/CMakeLists.txt  | 2 +-
 Sources/FoundationEssentials/Data/Data.swift | 8 ++++----
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Package.swift b/Package.swift
index d0c25c67d..a2b1ccf4b 100644
--- a/Package.swift
+++ b/Package.swift
@@ -147,7 +147,7 @@ let package = Package(
           ] + wasiLibcCSettings,
           swiftSettings: [
             .enableExperimentalFeature("VariadicGenerics"),
-            .enableExperimentalFeature("Lifetimes"),
+            .enableExperimentalFeature("LifetimeDependence"),
             .enableExperimentalFeature("AddressableTypes"),
             .enableExperimentalFeature("AllowUnsafeAttribute"),
             .enableExperimentalFeature("BuiltinModule"),
diff --git a/Sources/FoundationEssentials/CMakeLists.txt b/Sources/FoundationEssentials/CMakeLists.txt
index d009cde11..a5a1e9c79 100644
--- a/Sources/FoundationEssentials/CMakeLists.txt
+++ b/Sources/FoundationEssentials/CMakeLists.txt
@@ -81,7 +81,7 @@ endif()
 
 target_compile_options(FoundationEssentials PRIVATE
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend VariadicGenerics>"
-    "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend Lifetimes>"
+    "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend LifetimeDependence>"
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend AddressableTypes>"
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend BuiltinModule>"
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend AccessLevelOnImport>"
diff --git a/Sources/FoundationEssentials/Data/Data.swift b/Sources/FoundationEssentials/Data/Data.swift
index db43f8d5d..462d03b3c 100644
--- a/Sources/FoundationEssentials/Data/Data.swift
+++ b/Sources/FoundationEssentials/Data/Data.swift
@@ -2212,7 +2212,7 @@ public struct Data : Equatable, Hashable, RandomAccessCollection, MutableCollect
     @available(macOS 10.14.4, iOS 12.2, watchOS 5.2, tvOS 12.2, *)
     @_alwaysEmitIntoClient
     public var bytes: RawSpan {
-        @_lifetime(borrow self)
+        @lifetime(borrow self)
         borrowing get {
             let buffer: UnsafeRawBufferPointer
             switch _representation {
@@ -2240,7 +2240,7 @@ public struct Data : Equatable, Hashable, RandomAccessCollection, MutableCollect
     @available(macOS 10.14.4, iOS 12.2, watchOS 5.2, tvOS 12.2, *)
     @_alwaysEmitIntoClient
     public var span: Span<UInt8> {
-        @_lifetime(borrow self)
+        @lifetime(borrow self)
         borrowing get {
             let span = unsafe bytes._unsafeView(as: UInt8.self)
             return _overrideLifetime(span, borrowing: self)
@@ -2250,7 +2250,7 @@ public struct Data : Equatable, Hashable, RandomAccessCollection, MutableCollect
     @available(macOS 10.14.4, iOS 12.2, watchOS 5.2, tvOS 12.2, *)
     @_alwaysEmitIntoClient
     public var mutableBytes: MutableRawSpan {
-        @_lifetime(&self)
+        @lifetime(&self)
         mutating get {
             let buffer: UnsafeMutableRawBufferPointer
             switch _representation {
@@ -2286,7 +2286,7 @@ public struct Data : Equatable, Hashable, RandomAccessCollection, MutableCollect
     @available(macOS 10.14.4, iOS 12.2, watchOS 5.2, tvOS 12.2, *)
     @_alwaysEmitIntoClient
     public var mutableSpan: MutableSpan<UInt8> {
-        @_lifetime(&self)
+        @lifetime(&self)
         mutating get {
 #if false // see https://github.com/swiftlang/swift/issues/81218
             var bytes = mutableBytes

From 29ffa3d071ead679de02854e85d703f4f4ef794e Mon Sep 17 00:00:00 2001
From: Guillaume Lessard <guillaume.lessard@apple.com>
Date: Wed, 19 Nov 2025 13:06:36 -0800
Subject: [PATCH 2/2] Revert "Use updated spelling for lifetime annotations."

This reverts commit b9bdc6ff329b06c5881481f23687e23a5757bcf0.
---
 Sources/FoundationEssentials/Data/Data+Reading.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sources/FoundationEssentials/Data/Data+Reading.swift b/Sources/FoundationEssentials/Data/Data+Reading.swift
index 4dd3714a3..a7421ead4 100644
--- a/Sources/FoundationEssentials/Data/Data+Reading.swift
+++ b/Sources/FoundationEssentials/Data/Data+Reading.swift
@@ -193,7 +193,7 @@ struct ReadBytesResult {
 }
 
 #if os(Windows)
-@_lifetime(pBuffer: copy pBuffer)
+@lifetime(pBuffer: copy pBuffer)
 private func read(from hFile: HANDLE, at path: PathOrURL,
                   into pBuffer: inout OutputRawSpan,
                   chunkSize dwChunk: Int = 4096, progress bProgress: Bool)