diff --git a/docs/ReferenceGuides/UnderscoredAttributes.md b/docs/ReferenceGuides/UnderscoredAttributes.md
index 07d66bc5013b9..5e1f1376b7c33 100644
--- a/docs/ReferenceGuides/UnderscoredAttributes.md
+++ b/docs/ReferenceGuides/UnderscoredAttributes.md
@@ -1131,15 +1131,17 @@ ways to misuse it:
   be reliably recovered through C interfaces like `dlsym`. If you want to
   implement a plugin-style interface, use `Bundle`/`NSBundle` if available, or
   export your plugin entry points as C entry points using `@_cdecl`.
-  
+- Don't use `@_silgen_name` when you need to make a change to an ABI-stable
+  declaration's signature that would normally alter its mangled name, but you
+  need to preserve the old mangled name for ABI compatibility. We used to use it
+  for this task, but `@abi` can do it with fewer limitations, more safety, and
+  better readability. If for some reason you do need `@_silgen_name`, you will
+  need to be careful that the change doesn't materially affect the actual
+  calling convention of the function in an incompatible way.
+
 Legitimate uses may include:
 
 - Use `@_silgen_name` if you're implementing the Swift runtime.
-- Use `@_silgen_name` if you need to make a change to an ABI-stable
-  declaration's signature that would normally alter its mangled name, but you
-  need to preserve the old mangled name for ABI compatibility. You will need
-  to be careful that the change doesn't materially affect the actual calling
-  convention of the function in an incompatible way.
 - Use `@_silgen_name` if certain declarations need to have predictable symbol
   names, such as to be easily referenced by linker scripts or other highly
   customized build environments (and it's OK for those predictable symbols to
diff --git a/docs/StandardLibraryProgrammersManual.md b/docs/StandardLibraryProgrammersManual.md
index fae6b2e6bf26e..10ca628e3385a 100644
--- a/docs/StandardLibraryProgrammersManual.md
+++ b/docs/StandardLibraryProgrammersManual.md
@@ -455,6 +455,8 @@ This attribute specifies the name that a declaration will have at link time. It
 1. To specify the symbol name of a Swift function so that it can be called from Swift-aware C. Such functions have bodies.
 2. To provide a Swift declaration which really represents a C declaration. Such functions do not have bodies.
 
+In the past it was sometimes used for ABI backwards compatibility hacks, but `@abi` does this job better.
+
 ##### Using `@_silgen_name` to call Swift from Swift-aware C
 
 Rather than hard-code Swift mangling into C code, `@_silgen_name` is used to provide a stable and known symbol name for linking. Note that C code still must understand and use the Swift calling convention (available in swift-clang) for such Swift functions (if they use Swift's CC). Example:
diff --git a/stdlib/cmake/modules/SwiftSource.cmake b/stdlib/cmake/modules/SwiftSource.cmake
index a7893dfec0f73..eea2765736e80 100644
--- a/stdlib/cmake/modules/SwiftSource.cmake
+++ b/stdlib/cmake/modules/SwiftSource.cmake
@@ -637,6 +637,7 @@ function(_compile_swift_files
   list(APPEND swift_flags "-enable-experimental-feature" "LifetimeDependence")
   list(APPEND swift_flags "-enable-experimental-feature" "InoutLifetimeDependence")
   list(APPEND swift_flags "-enable-experimental-feature" "LifetimeDependenceMutableAccessors")
+  list(APPEND swift_flags "-enable-experimental-feature" "ABIAttribute")
 
   list(APPEND swift_flags "-enable-upcoming-feature" "MemberImportVisibility")
 
diff --git a/stdlib/public/Concurrency/AsyncStream.swift b/stdlib/public/Concurrency/AsyncStream.swift
index ca6eb979695c1..ae26ebad1e563 100644
--- a/stdlib/public/Concurrency/AsyncStream.swift
+++ b/stdlib/public/Concurrency/AsyncStream.swift
@@ -330,7 +330,12 @@ public struct AsyncStream<Element> {
   ///     }
   ///
   ///
-  @_silgen_name("$sScS9unfolding8onCancelScSyxGxSgyYac_yyYbcSgtcfC")
+  @abi(
+    init(
+      unfolding produce: @escaping /* not @Sendable*/ () async -> Element?,
+      onCancel: (@Sendable () -> Void)?
+    )
+  )
   @preconcurrency // Original API had `@Sendable` only on `onCancel`
   public init(
     unfolding produce: @escaping @Sendable () async -> Element?,
diff --git a/stdlib/public/Concurrency/CheckedContinuation.swift b/stdlib/public/Concurrency/CheckedContinuation.swift
index a4f0f1553d050..06aca69367a96 100644
--- a/stdlib/public/Concurrency/CheckedContinuation.swift
+++ b/stdlib/public/Concurrency/CheckedContinuation.swift
@@ -313,9 +313,14 @@ public func withCheckedContinuation<T>(
 //
 // This function also doubles as an ABI-compatibility shim predating the
 // introduction of #isolation.
+@abi(
+  func withCheckedContinuation<T>(
+    function: String,
+    _ body: (CheckedContinuation<T, Never>) -> Void
+  ) async -> T
+)
 @available(SwiftStdlib 5.1, *)
 @_unsafeInheritExecutor // ABI compatibility with Swift 5.1
-@_silgen_name("$ss23withCheckedContinuation8function_xSS_yScCyxs5NeverOGXEtYalF")
 public func _unsafeInheritExecutor_withCheckedContinuation<T>(
   function: String = #function,
   _ body: (CheckedContinuation<T, Never>) -> Void
@@ -377,9 +382,14 @@ public func withCheckedThrowingContinuation<T>(
 //
 // This function also doubles as an ABI-compatibility shim predating the
 // introduction of #isolation.
+@abi(
+  func withCheckedThrowingContinuation<T>(
+    function: String,
+    _ body: (CheckedContinuation<T, Error>) -> Void
+  ) async throws -> T
+)
 @available(SwiftStdlib 5.1, *)
 @_unsafeInheritExecutor // ABI compatibility with Swift 5.1
-@_silgen_name("$ss31withCheckedThrowingContinuation8function_xSS_yScCyxs5Error_pGXEtYaKlF")
 public func _unsafeInheritExecutor_withCheckedThrowingContinuation<T>(
   function: String = #function,
   _ body: (CheckedContinuation<T, Error>) -> Void
diff --git a/stdlib/public/Concurrency/Clock.swift b/stdlib/public/Concurrency/Clock.swift
index 8c6864ca3447c..dffa58ba039a9 100644
--- a/stdlib/public/Concurrency/Clock.swift
+++ b/stdlib/public/Concurrency/Clock.swift
@@ -127,8 +127,12 @@ extension Clock {
   //
   // This function also doubles as an ABI-compatibility shim predating the
   // introduction of #isolation.
+  @abi(
+    func measure(
+        _ work: () async throws -> Void
+    ) async rethrows -> Instant.Duration
+  )
   @available(SwiftStdlib 5.7, *)
-  @_silgen_name("$ss5ClockPsE7measurey8DurationQzyyYaKXEYaKF")
   @_unsafeInheritExecutor // for ABI compatibility
   public func _unsafeInheritExecutor_measure(
     _ work: () async throws -> Void
diff --git a/stdlib/public/Concurrency/DiscardingTaskGroup.swift b/stdlib/public/Concurrency/DiscardingTaskGroup.swift
index 1de2e5311abcf..8cd24a9730a54 100644
--- a/stdlib/public/Concurrency/DiscardingTaskGroup.swift
+++ b/stdlib/public/Concurrency/DiscardingTaskGroup.swift
@@ -97,9 +97,14 @@ public func withDiscardingTaskGroup<GroupResult>(
 //
 // This function also doubles as an ABI-compatibility shim predating the
 // introduction of #isolation.
+@abi(
+  func withDiscardingTaskGroup<GroupResult>(
+    returning returnType: GroupResult.Type,
+    body: (inout DiscardingTaskGroup) async -> GroupResult
+  ) async -> GroupResult
+)
 @available(SwiftStdlib 5.9, *)
 @_unsafeInheritExecutor // for ABI compatibility
-@_silgen_name("$ss23withDiscardingTaskGroup9returning4bodyxxm_xs0bcD0VzYaXEtYalF")
 public func _unsafeInheritExecutor_withDiscardingTaskGroup<GroupResult>(
   returning returnType: GroupResult.Type = GroupResult.self,
   body: (inout DiscardingTaskGroup) async -> GroupResult
@@ -367,9 +372,14 @@ public func withThrowingDiscardingTaskGroup<GroupResult>(
   return result
 }
 
+@abi(
+  func withThrowingDiscardingTaskGroup<GroupResult>(
+      returning returnType: GroupResult.Type,
+      body: (inout ThrowingDiscardingTaskGroup<Error>) async throws -> GroupResult
+  ) async throws -> GroupResult
+)
 @available(SwiftStdlib 5.9, *)
 @_unsafeInheritExecutor // for ABI compatibility
-@_silgen_name("$ss31withThrowingDiscardingTaskGroup9returning4bodyxxm_xs0bcdE0Vys5Error_pGzYaKXEtYaKlF")
 public func _unsafeInheritExecutor_withThrowingDiscardingTaskGroup<GroupResult>(
     returning returnType: GroupResult.Type = GroupResult.self,
     body: (inout ThrowingDiscardingTaskGroup<Error>) async throws -> GroupResult
diff --git a/stdlib/public/Concurrency/ExecutorAssertions.swift b/stdlib/public/Concurrency/ExecutorAssertions.swift
index 79143faad9c62..e06dfb6db22c0 100644
--- a/stdlib/public/Concurrency/ExecutorAssertions.swift
+++ b/stdlib/public/Concurrency/ExecutorAssertions.swift
@@ -368,11 +368,16 @@ extension Actor {
     }
   }
 
+  @abi(
+    nonisolated func assumeIsolated<T /* not ': Sendable' */>(
+        _ operation: (isolated Self) throws -> T,
+        file: StaticString, line: UInt
+    ) rethrows -> T
+  )
   @available(SwiftStdlib 5.9, *)
   @usableFromInline
   @_unavailableInEmbedded
-  @_silgen_name("$sScAsE14assumeIsolated_4file4lineqd__qd__xYiKXE_s12StaticStringVSutKlF")
-  internal nonisolated func __abi__assumeIsolated<T : Sendable>(
+  internal nonisolated func __nonsendable_assumeIsolated<T : Sendable>(
       _ operation: (isolated Self) throws -> T,
       _ file: StaticString, _ line: UInt
   ) rethrows -> T {
diff --git a/stdlib/public/Concurrency/MainActor.swift b/stdlib/public/Concurrency/MainActor.swift
index cddb4f83162b6..65532024e9015 100644
--- a/stdlib/public/Concurrency/MainActor.swift
+++ b/stdlib/public/Concurrency/MainActor.swift
@@ -152,10 +152,15 @@ extension MainActor {
     }
   }
 
+  @abi(
+    static func assumeIsolated<T /* not ': Sendable' */>(
+        _ operation: @MainActor () throws -> T,
+        file: StaticString, line: UInt
+    ) rethrows -> T
+  )
   @available(SwiftStdlib 5.9, *)
   @usableFromInline
-  @_silgen_name("$sScM14assumeIsolated_4file4linexxyKScMYcXE_s12StaticStringVSutKlFZ")
-  internal static func __abi__assumeIsolated<T : Sendable>(
+  internal static func __nonsendable_assumeIsolated<T : Sendable>(
       _ operation: @MainActor () throws -> T,
       _ file: StaticString, _ line: UInt
   ) rethrows -> T {
diff --git a/stdlib/public/Concurrency/Task+TaskExecutor.swift b/stdlib/public/Concurrency/Task+TaskExecutor.swift
index 611fe9265630f..6d1fcd62e9f0e 100644
--- a/stdlib/public/Concurrency/Task+TaskExecutor.swift
+++ b/stdlib/public/Concurrency/Task+TaskExecutor.swift
@@ -164,10 +164,15 @@ public func withTaskExecutorPreference<T, Failure>(
 //
 // This function also doubles as an ABI-compatibility shim predating the
 // introduction of #isolation.
+@abi(
+  func withTaskExecutorPreference<T: Sendable>(
+    _ taskExecutor: (any TaskExecutor)?,
+    operation: @Sendable () async throws -> T
+  ) async rethrows -> T
+)
 @_unavailableInEmbedded
 @available(SwiftStdlib 6.0, *)
 @_unsafeInheritExecutor // for ABI compatibility
-@_silgen_name("$ss26withTaskExecutorPreference_9operationxSch_pSg_xyYaYbKXEtYaKs8SendableRzlF")
 public func _unsafeInheritExecutor_withTaskExecutorPreference<T: Sendable>(
   _ taskExecutor: (any TaskExecutor)?,
   operation: @Sendable () async throws -> T
diff --git a/stdlib/public/Concurrency/TaskCancellation.swift b/stdlib/public/Concurrency/TaskCancellation.swift
index 62ce412e60798..04a8b79efae44 100644
--- a/stdlib/public/Concurrency/TaskCancellation.swift
+++ b/stdlib/public/Concurrency/TaskCancellation.swift
@@ -89,9 +89,14 @@ public func withTaskCancellationHandler<T>(
 //
 // This function also doubles as an ABI-compatibility shim predating the
 // introduction of #isolation.
+@abi(
+  func withTaskCancellationHandler<T>(
+    operation: () async throws -> T,
+    onCancel handler: @Sendable () -> Void
+  ) async rethrows -> T
+)
 @_unsafeInheritExecutor // ABI compatibility with Swift 5.1
 @available(SwiftStdlib 5.1, *)
-@_silgen_name("$ss27withTaskCancellationHandler9operation8onCancelxxyYaKXE_yyYbXEtYaKlF")
 public func _unsafeInheritExecutor_withTaskCancellationHandler<T>(
   operation: () async throws -> T,
   onCancel handler: @Sendable () -> Void
diff --git a/stdlib/public/Concurrency/TaskGroup.swift b/stdlib/public/Concurrency/TaskGroup.swift
index 3b0e4728c5cac..9f89515d59138 100644
--- a/stdlib/public/Concurrency/TaskGroup.swift
+++ b/stdlib/public/Concurrency/TaskGroup.swift
@@ -97,8 +97,15 @@ public func withTaskGroup<ChildTaskResult, GroupResult>(
 //
 // This function also doubles as an ABI-compatibility shim predating the
 // introduction of #isolation.
+@abi(
+  @preconcurrency   // TaskGroup.ChildTaskResult: Sendable
+  func withTaskGroup<ChildTaskResult, GroupResult>(
+    of childTaskResultType: ChildTaskResult.Type,
+    returning returnType: GroupResult.Type,
+    body: (inout TaskGroup<ChildTaskResult>) async -> GroupResult
+  ) async -> GroupResult
+)
 @available(SwiftStdlib 5.1, *)
-@_silgen_name("$ss13withTaskGroup2of9returning4bodyq_xm_q_mq_ScGyxGzYaXEtYar0_lF")
 @_unsafeInheritExecutor // for ABI compatibility
 @inlinable
 public func _unsafeInheritExecutor_withTaskGroup<ChildTaskResult, GroupResult>(
@@ -243,8 +250,15 @@ public func withThrowingTaskGroup<ChildTaskResult, GroupResult>(
 //
 // This function also doubles as an ABI-compatibility shim predating the
 // introduction of #isolation.
+@abi(
+  @preconcurrency   // ThrowingTaskGroup.ChildTaskResult: Sendable
+  func withThrowingTaskGroup<ChildTaskResult, GroupResult>(
+    of childTaskResultType: ChildTaskResult.Type,
+    returning returnType: GroupResult.Type,
+    body: (inout ThrowingTaskGroup<ChildTaskResult, Error>) async throws -> GroupResult
+  ) async rethrows -> GroupResult
+)
 @available(SwiftStdlib 5.1, *)
-@_silgen_name("$ss21withThrowingTaskGroup2of9returning4bodyq_xm_q_mq_Scgyxs5Error_pGzYaKXEtYaKr0_lF")
 @_unsafeInheritExecutor // for ABI compatibility
 public func _unsafeInheritExecutor_withThrowingTaskGroup<ChildTaskResult, GroupResult>(
   of childTaskResultType: ChildTaskResult.Type,
@@ -690,7 +704,7 @@ public struct ThrowingTaskGroup<ChildTaskResult: Sendable, Failure: Error> {
     return try await _taskGroupWaitNext(group: _group)
   }
 
-  @_silgen_name("$sScg10nextResults0B0Oyxq_GSgyYaKF")
+  @abi(mutating func nextResult() async throws -> Result<ChildTaskResult, Failure>?)
   @usableFromInline
   mutating func nextResultForABI() async throws -> Result<ChildTaskResult, Failure>? {
     do {
diff --git a/stdlib/public/Concurrency/TaskLocal.swift b/stdlib/public/Concurrency/TaskLocal.swift
index df1811d14d6e6..8ff12abb98e6f 100644
--- a/stdlib/public/Concurrency/TaskLocal.swift
+++ b/stdlib/public/Concurrency/TaskLocal.swift
@@ -221,10 +221,16 @@ public final class TaskLocal<Value: Sendable>: Sendable, CustomStringConvertible
   //
   // This function also doubles as an ABI-compatibility shim predating the
   // introduction of #isolation.
+  @abi(
+    func withValue<R>(
+      _ valueDuringOperation: Value,
+      operation: () async throws -> R,
+      file: String, line: UInt
+    ) async rethrows -> R
+  )
   @discardableResult
   @_unsafeInheritExecutor // ABI compatibility with Swift 5.1
   @available(SwiftStdlib 5.1, *)
-  @_silgen_name("$ss9TaskLocalC9withValue_9operation4file4lineqd__x_qd__yYaKXESSSutYaKlF")
   public func _unsafeInheritExecutor_withValue<R>(
     _ valueDuringOperation: Value,
     operation: () async throws -> R,
@@ -265,7 +271,13 @@ public final class TaskLocal<Value: Sendable>: Sendable, CustomStringConvertible
     return try await operation()
   }
 
-  @_silgen_name("$ss9TaskLocalC13withValueImpl_9operation4file4lineqd__xn_qd__yYaKXESSSutYaKlF")
+  @abi(
+    func withValueImpl<R>(
+      _ valueDuringOperation: __owned Value,
+      operation: () async throws -> R,
+      file: String, line: UInt
+    ) async rethrows -> R
+  )
   @inlinable
   @discardableResult
   @_unsafeInheritExecutor // internal for backwards compatibility; though may be able to be removed safely?
diff --git a/stdlib/public/Distributed/DistributedActor.swift b/stdlib/public/Distributed/DistributedActor.swift
index a2df218e2e45c..93ddc3045d11a 100644
--- a/stdlib/public/Distributed/DistributedActor.swift
+++ b/stdlib/public/Distributed/DistributedActor.swift
@@ -362,10 +362,15 @@ extension DistributedActor {
   /// state.
   ///
   /// When the actor is remote, the closure won't be executed and this function will return nil.
+  @abi(
+    // We need to @abi here because the signature is the same as
+    // `__separately_compiled_typed_throws_whenLocal(_:)`, and even though this
+    // is @AEIC, the symbol name would conflict.
+    nonisolated func __typed_throws_whenLocal<T: Sendable, E>(
+      _ body: @Sendable (isolated Self) async throws(E) -> T
+    ) async throws(E) -> T?
+  )
   @_alwaysEmitIntoClient
-  // we need to silgen_name here because the signature is the same as __abi_whenLocal,
-  // and even though this is @AEIC, the symbol name would conflict.
-  @_silgen_name("$s11Distributed0A5ActorPAAE20whenLocalTypedThrowsyqd__Sgqd__xYiYaYbqd_0_YKXEYaqd_0_YKs8SendableRd__s5ErrorRd_0_r0_lF")
   public nonisolated func whenLocal<T: Sendable, E>(
     _ body: @Sendable (isolated Self) async throws(E) -> T
   ) async throws(E) -> T? {
@@ -380,18 +385,26 @@ extension DistributedActor {
   // ABI: This is a workaround when in Swift 6 this method was introduced
   // in order to support typed-throws, but missed to add @_aeic.
   // In practice, this method should not ever be used by anyone, ever.
+  @abi(
+    nonisolated func whenLocal<T: Sendable, E>(
+      _ body: @Sendable (isolated Self) async throws(E) -> T
+    ) async throws(E) -> T?
+  )
   @usableFromInline
-  @_silgen_name("$s11Distributed0A5ActorPAAE9whenLocalyqd__Sgqd__xYiYaYbqd_0_YKXEYaqd_0_YKs8SendableRd__s5ErrorRd_0_r0_lF")
-  internal nonisolated func __abi_whenLocal<T: Sendable, E>(
+  nonisolated func __separately_compiled_typed_throws_whenLocal<T: Sendable, E>(
     _ body: @Sendable (isolated Self) async throws(E) -> T
   ) async throws(E) -> T? {
     try await whenLocal(body)
   }
 
   // ABI: Historical whenLocal, rethrows was changed to typed throws `throws(E)`
-  @_silgen_name("$s11Distributed0A5ActorPAAE9whenLocalyqd__Sgqd__xYiYaYbKXEYaKs8SendableRd__lF")
+  @abi(
+    nonisolated func whenLocal<T: Sendable>(
+      _ body: @Sendable (isolated Self) async throws -> T
+    ) async rethrows -> T?
+  )
   @usableFromInline
-  nonisolated func __abi_whenLocal<T: Sendable>(
+  nonisolated func __rethrows_whenLocal<T: Sendable>(
     _ body: @Sendable (isolated Self) async throws -> T
   ) async rethrows -> T? {
     try await whenLocal(body)
diff --git a/stdlib/public/Distributed/DistributedAssertions.swift b/stdlib/public/Distributed/DistributedAssertions.swift
index 881741904c81d..3e749337267c6 100644
--- a/stdlib/public/Distributed/DistributedAssertions.swift
+++ b/stdlib/public/Distributed/DistributedAssertions.swift
@@ -179,10 +179,15 @@ extension DistributedActor {
     }
   }
 
+  @abi(
+    nonisolated func assumeIsolated<T /* not ': Sendable' */>(
+      _ operation: (isolated Self) throws -> T,
+      file: StaticString, line: UInt
+    ) rethrows -> T
+  )
   @available(SwiftStdlib 5.9, *)
   @usableFromInline
-  @_silgen_name("$s11Distributed0A5ActorPAAE14assumeIsolated_4file4lineqd__qd__xYiKXE_s12StaticStringVSutKlF")
-  internal nonisolated func __abi__assumeIsolated<T : Sendable>(
+  internal nonisolated func __nonsendable_assumeIsolated<T : Sendable>(
       _ operation: (isolated Self) throws -> T,
       _ file: StaticString, _ line: UInt
   ) rethrows -> T {
diff --git a/stdlib/public/core/Array.swift b/stdlib/public/core/Array.swift
index e0798e8597782..8ddf4b6aaa3a0 100644
--- a/stdlib/public/core/Array.swift
+++ b/stdlib/public/core/Array.swift
@@ -1634,12 +1634,16 @@ extension Array {
 
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
+  @abi(
+    mutating func withUnsafeMutableBufferPointer<R>(
+      _ body: (inout UnsafeMutableBufferPointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @_semantics("array.withUnsafeMutableBufferPointer")
   @_effects(notEscaping self.value**)
   @usableFromInline
   @inline(__always)
-  @_silgen_name("$sSa30withUnsafeMutableBufferPointeryqd__qd__SryxGzKXEKlF")
-  mutating func __abi_withUnsafeMutableBufferPointer<R>(
+  mutating func __rethrows_withUnsafeMutableBufferPointer<R>(
     _ body: (inout UnsafeMutableBufferPointer<Element>) throws -> R
   ) rethrows -> R {
     _makeMutableAndUnique()
diff --git a/stdlib/public/core/ArrayBuffer.swift b/stdlib/public/core/ArrayBuffer.swift
index 777d868016eeb..0513da27cbea8 100644
--- a/stdlib/public/core/ArrayBuffer.swift
+++ b/stdlib/public/core/ArrayBuffer.swift
@@ -649,9 +649,13 @@ extension _ArrayBuffer {
   /// created on-demand.
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
+  @abi(
+    func withUnsafeBufferPointer<R>(
+      _ body: (UnsafeBufferPointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @usableFromInline
-  @_silgen_name("$ss12_ArrayBufferV010withUnsafeB7Pointeryqd__qd__SRyxGKXEKlF")
-  internal func __abi_withUnsafeBufferPointer<R>(
+  internal func __rethrows_withUnsafeBufferPointer<R>(
     _ body: (UnsafeBufferPointer<Element>) throws -> R
   ) rethrows -> R {
     if _fastPath(_isNative) {
@@ -679,9 +683,13 @@ extension _ArrayBuffer {
 
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
+  @abi(
+    mutating func withUnsafeMutableBufferPointer<R>(
+      _ body: (UnsafeMutableBufferPointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @usableFromInline
-  @_silgen_name("$ss12_ArrayBufferV017withUnsafeMutableB7Pointeryqd__qd__SryxGKXEKlF")
-  internal mutating func __abi_withUnsafeMutableBufferPointer<R>(
+  internal mutating func __rethrows_withUnsafeMutableBufferPointer<R>(
     _ body: (UnsafeMutableBufferPointer<Element>) throws -> R
   ) rethrows -> R {
     return try unsafe withUnsafeMutableBufferPointer(body)
diff --git a/stdlib/public/core/ArraySlice.swift b/stdlib/public/core/ArraySlice.swift
index 2d312f763071c..f60dfdfc4c55c 100644
--- a/stdlib/public/core/ArraySlice.swift
+++ b/stdlib/public/core/ArraySlice.swift
@@ -1223,11 +1223,15 @@ extension ArraySlice {
 
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
+  @abi(
+    mutating func withUnsafeMutableBufferPointer<R>(
+      _ body: (inout UnsafeMutableBufferPointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @_semantics("array.withUnsafeMutableBufferPointer")
   @usableFromInline
   @inline(__always)
-  @_silgen_name("$ss10ArraySliceV30withUnsafeMutableBufferPointeryqd__qd__SryxGzKXEKlF")
-  mutating func __abi_withUnsafeMutableBufferPointer<R>(
+  mutating func __rethrows_withUnsafeMutableBufferPointer<R>(
     _ body: (inout UnsafeMutableBufferPointer<Element>) throws -> R
   ) rethrows -> R {
     return try unsafe withUnsafeMutableBufferPointer(body)
diff --git a/stdlib/public/core/Builtin.swift b/stdlib/public/core/Builtin.swift
index a2bea81aec659..2831556bb8d2c 100644
--- a/stdlib/public/core/Builtin.swift
+++ b/stdlib/public/core/Builtin.swift
@@ -983,8 +983,8 @@ public func type<T: ~Copyable & ~Escapable, Metatype>(
   Builtin.unreachable()
 }
 
+@abi(func type<T, Metatype>(of _: T) -> Metatype)
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss4type2ofq_x_tr0_lF")
 @usableFromInline
 func __abi_type<T, Metatype>(of value: T) -> Metatype {
   // This is a legacy entry point for the original definition of `type(of:)`
@@ -1091,9 +1091,14 @@ public func withoutActuallyEscaping<ClosureType, ResultType, Failure>(
   Builtin.unreachable()
 }
 
-@_silgen_name("$ss23withoutActuallyEscaping_2doq_x_q_xKXEtKr0_lF")
+@abi(
+  func withoutActuallyEscaping<ClosureType, ResultType>(
+    _ closure: ClosureType,
+    do body: (_ escapingClosure: ClosureType) throws -> ResultType
+  ) throws -> ResultType
+)
 @usableFromInline
-func __abi_withoutActuallyEscaping<ClosureType, ResultType>(
+func __rethrows_withoutActuallyEscaping<ClosureType, ResultType>(
   _ closure: ClosureType,
   do body: (_ escapingClosure: ClosureType) throws -> ResultType
 ) throws -> ResultType {
@@ -1122,9 +1127,14 @@ public func _openExistential<ExistentialType, ContainedType, ResultType, Failure
   Builtin.unreachable()
 }
 
+@abi(
+  func _openExistential<ExistentialType, ContainedType, ResultType>(
+    _ existential: ExistentialType,
+    do body: (_ escapingClosure: ContainedType) throws -> ResultType
+  ) throws -> ResultType
+)
 @usableFromInline
-@_silgen_name("$ss16_openExistential_2doq0_x_q0_q_KXEtKr1_lF")
-func __abi_openExistential<ExistentialType, ContainedType, ResultType>(
+func __rethrows_openExistential<ExistentialType, ContainedType, ResultType>(
   _ existential: ExistentialType,
   do body: (_ escapingClosure: ContainedType) throws -> ResultType
 ) throws -> ResultType {
diff --git a/stdlib/public/core/CString.swift b/stdlib/public/core/CString.swift
index caa56549530b0..8f0ccae72100e 100644
--- a/stdlib/public/core/CString.swift
+++ b/stdlib/public/core/CString.swift
@@ -186,7 +186,7 @@ extension String {
   ///
   /// - Parameter nullTerminatedUTF8:
   ///     A pointer to a null-terminated sequence of UTF-8 code units.
-  @_silgen_name("$sSS14validatingUTF8SSSgSPys4Int8VG_tcfC")
+  @abi(init?(validatingUTF8 nullTerminatedUTF8: UnsafePointer<CChar>))
   public init?(validatingCString nullTerminatedUTF8: UnsafePointer<CChar>) {
     let len = unsafe UTF8._nullCodeUnitOffset(in: nullTerminatedUTF8)
     let validated = unsafe nullTerminatedUTF8.withMemoryRebound(
@@ -231,7 +231,7 @@ extension String {
   @inlinable
   @_alwaysEmitIntoClient
   @available(swift, deprecated: 6, renamed: "String.init(validatingCString:)")
-  @_silgen_name("_swift_se0405_String_validatingUTF8")
+  @abi(init?(validatingCString nullTerminatedUTF8: UnsafePointer<CChar>))
   public init?(validatingUTF8 cString: UnsafePointer<CChar>) {
     unsafe self.init(validatingCString: cString)
   }
diff --git a/stdlib/public/core/Collection.swift b/stdlib/public/core/Collection.swift
index b56f3d15b9d6d..018326fd32f61 100644
--- a/stdlib/public/core/Collection.swift
+++ b/stdlib/public/core/Collection.swift
@@ -1214,11 +1214,14 @@ extension Collection {
   }
 
   // ABI-only entrypoint for the rethrows version of map, which has been
-  // superseded by the typed-throws version. Expressed as "throws", which is
-  // ABI-compatible with "rethrows".
+  // superseded by the typed-throws version.
+  @abi(
+    func map<T>(
+      _ transform: (Element) throws -> T
+    ) rethrows -> [T]
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
   @usableFromInline
-  @_silgen_name("$sSlsE3mapySayqd__Gqd__7ElementQzKXEKlF")
   func __rethrows_map<T>(
     _ transform: (Element) throws -> T
   ) throws -> [T] {
diff --git a/stdlib/public/core/ContiguousArray.swift b/stdlib/public/core/ContiguousArray.swift
index 6537d818ab188..5ab7e4ae42f7a 100644
--- a/stdlib/public/core/ContiguousArray.swift
+++ b/stdlib/public/core/ContiguousArray.swift
@@ -1166,11 +1166,15 @@ extension ContiguousArray {
 
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
+  @abi(
+    mutating func withUnsafeMutableBufferPointer<R>(
+      _ body: (inout UnsafeMutableBufferPointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @_semantics("array.withUnsafeMutableBufferPointer")
   @usableFromInline
   @inline(__always)
-  @_silgen_name("$ss15ContiguousArrayV30withUnsafeMutableBufferPointeryqd__qd__SryxGzKXEKlF")
-  mutating func __abi_withUnsafeMutableBufferPointer<R>(
+  mutating func __rethrows_withUnsafeMutableBufferPointer<R>(
     _ body: (inout UnsafeMutableBufferPointer<Element>) throws -> R
   ) rethrows -> R {
     return try unsafe withUnsafeMutableBufferPointer(body)
diff --git a/stdlib/public/core/ContiguousArrayBuffer.swift b/stdlib/public/core/ContiguousArrayBuffer.swift
index f49d15fb5afb1..7130feddd9f10 100644
--- a/stdlib/public/core/ContiguousArrayBuffer.swift
+++ b/stdlib/public/core/ContiguousArrayBuffer.swift
@@ -447,9 +447,13 @@ internal struct _ContiguousArrayBuffer<Element>: _ArrayBufferProtocol {
 
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
+  @abi(
+    func withUnsafeBufferPointer<R>(
+      _ body: (UnsafeBufferPointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @usableFromInline
-  @_silgen_name("$ss22_ContiguousArrayBufferV010withUnsafeC7Pointeryqd__qd__SRyxGKXEKlF")
-  internal func __abi_withUnsafeBufferPointer<R>(
+  internal func __rethrows_withUnsafeBufferPointer<R>(
     _ body: (UnsafeBufferPointer<Element>) throws -> R
   ) rethrows -> R {
     defer { _fixLifetime(self) }
@@ -470,9 +474,13 @@ internal struct _ContiguousArrayBuffer<Element>: _ArrayBufferProtocol {
 
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
+  @abi(
+    mutating func withUnsafeMutableBufferPointer<R>(
+      _ body: (UnsafeMutableBufferPointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @usableFromInline
-  @_silgen_name("$ss22_ContiguousArrayBufferV017withUnsafeMutableC7Pointeryqd__qd__SryxGKXEKlF")
-  internal mutating func __abi_withUnsafeMutableBufferPointer<R>(
+  internal mutating func __rethrows_withUnsafeMutableBufferPointer<R>(
     _ body: (UnsafeMutableBufferPointer<Element>) throws -> R
   ) rethrows -> R {
     defer { _fixLifetime(self) }
diff --git a/stdlib/public/core/ExistentialCollection.swift b/stdlib/public/core/ExistentialCollection.swift
index 13d412b8704b4..c8a15fd8c681e 100644
--- a/stdlib/public/core/ExistentialCollection.swift
+++ b/stdlib/public/core/ExistentialCollection.swift
@@ -1335,11 +1335,14 @@ extension AnySequence {
   }
 
   // ABI-only entrypoint for the rethrows version of map, which has been
-  // superseded by the typed-throws version. Expressed as "throws", which is
-  // ABI-compatible with "rethrows".
+  // superseded by the typed-throws version.
+  @abi(
+    func map<T>(
+      _ transform: (Element) throws -> T
+    ) rethrows -> [T]
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
   @usableFromInline
-  @_silgen_name("$ss11AnySequenceV3mapySayqd__Gqd__xKXEKlF")
   func __rethrows_map<T>(
     _ transform: (Element) throws -> T
   ) throws -> [T] {
@@ -1439,11 +1442,14 @@ extension AnyCollection {
   }
 
   // ABI-only entrypoint for the rethrows version of map, which has been
-  // superseded by the typed-throws version. Expressed as "throws", which is
-  // ABI-compatible with "rethrows".
+  // superseded by the typed-throws version.
+  @abi(
+    func map<T>(
+      _ transform: (Element) throws -> T
+    ) rethrows -> [T]
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
   @usableFromInline
-  @_silgen_name("$ss13AnyCollectionV3mapySayqd__Gqd__xKXEKlF")
   func __rethrows_map<T>(
     _ transform: (Element) throws -> T
   ) throws -> [T] {
@@ -1549,11 +1555,14 @@ extension AnyBidirectionalCollection {
   }
 
   // ABI-only entrypoint for the rethrows version of map, which has been
-  // superseded by the typed-throws version. Expressed as "throws", which is
-  // ABI-compatible with "rethrows".
+  // superseded by the typed-throws version.
+  @abi(
+    func map<T>(
+      _ transform: (Element) throws -> T
+    ) rethrows -> [T]
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
   @usableFromInline
-  @_silgen_name("$ss26AnyBidirectionalCollectionV3mapySayqd__Gqd__xKXEKlF")
   func __rethrows_map<T>(
     _ transform: (Element) throws -> T
   ) throws -> [T] {
@@ -1663,9 +1672,13 @@ extension AnyRandomAccessCollection {
   // ABI-only entrypoint for the rethrows version of map, which has been
   // superseded by the typed-throws version. Expressed as "throws", which is
   // ABI-compatible with "rethrows".
+  @abi(
+    func map<T>(
+      _ transform: (Element) throws -> T
+    ) rethrows -> [T]
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
   @usableFromInline
-  @_silgen_name("$ss25AnyRandomAccessCollectionV3mapySayqd__Gqd__xKXEKlF")
   func __rethrows_map<T>(
     _ transform: (Element) throws -> T
   ) throws -> [T] {
diff --git a/stdlib/public/core/LifetimeManager.swift b/stdlib/public/core/LifetimeManager.swift
index eeaeba32b2484..070cb295c4216 100644
--- a/stdlib/public/core/LifetimeManager.swift
+++ b/stdlib/public/core/LifetimeManager.swift
@@ -43,10 +43,14 @@ public func withExtendedLifetime<
   return try body()
 }
 
+@abi(
+  func withExtendedLifetime<T, Result>(
+    _ x: T, _ body: () throws -> Result
+  ) rethrows -> Result
+)
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss20withExtendedLifetimeyq_x_q_yKXEtKr0_lF")
 @usableFromInline
-internal func __abi_withExtendedLifetime<T, Result>(
+internal func __rethrows_withExtendedLifetime<T, Result>(
   _ x: T,
   _ body: () throws -> Result
 ) rethrows -> Result {
@@ -76,10 +80,14 @@ public func withExtendedLifetime<
   return try body(x)
 }
 
+@abi(
+  func withExtendedLifetime<T, Result>(
+    _ x: T, _ body: (T) throws -> Result
+  ) rethrows -> Result
+)
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss20withExtendedLifetimeyq_x_q_xKXEtKr0_lF")
 @usableFromInline
-internal func __abi_withExtendedLifetime<T, Result>(
+internal func __rethrows_withExtendedLifetime<T, Result>(
   _ x: T, _ body: (T) throws -> Result
 ) rethrows -> Result {
   defer { _fixLifetime(x) }
@@ -126,8 +134,13 @@ public func withUnsafeMutablePointer<
   try unsafe body(UnsafeMutablePointer<T>(Builtin.addressof(&value)))
 }
 
+@abi(
+  func withUnsafeMutablePointer<T, Result>(
+    to value: inout T,
+    _ body: (UnsafeMutablePointer<T>) throws -> Result
+  ) throws -> Result
+)
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss24withUnsafeMutablePointer2to_q_xz_q_SpyxGKXEtKr0_lF")
 @usableFromInline
 internal func __abi_se0413_withUnsafeMutablePointer<T, Result>(
   to value: inout T,
@@ -186,10 +199,15 @@ public func withUnsafePointer<T: ~Copyable, E: Error, Result: ~Copyable>(
 
 /// ABI: Historical withUnsafePointer(to:_:) rethrows, expressed as "throws",
 /// which is ABI-compatible with "rethrows".
+@abi(
+  func withUnsafePointer<T, Result>(
+    to value: T,
+    _ body: (UnsafePointer<T>) throws -> Result
+  ) throws -> Result
+)
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss17withUnsafePointer2to_q_x_q_SPyxGKXEtKr0_lF")
 @usableFromInline
-internal func __abi_withUnsafePointer<T, Result>(
+internal func __rethrows_withUnsafePointer<T, Result>(
   to value: T,
   _ body: (UnsafePointer<T>) throws -> Result
 ) throws -> Result
@@ -231,8 +249,13 @@ public func withUnsafePointer<T: ~Copyable, E: Error, Result: ~Copyable>(
 
 /// ABI: Historical withUnsafePointer(to:_:) rethrows,
 /// expressed as "throws", which is ABI-compatible with "rethrows".
+@abi(
+  func withUnsafePointer<T, Result>(
+    to value: inout T,
+    _ body: (UnsafePointer<T>) throws -> Result
+  ) throws -> Result
+)
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss17withUnsafePointer2to_q_xz_q_SPyxGKXEtKr0_lF")
 @usableFromInline
 internal func __abi_se0413_withUnsafePointer<T, Result>(
   to value: inout T,
diff --git a/stdlib/public/core/ManagedBuffer.swift b/stdlib/public/core/ManagedBuffer.swift
index 99b36341c30f0..00e658a05a7df 100644
--- a/stdlib/public/core/ManagedBuffer.swift
+++ b/stdlib/public/core/ManagedBuffer.swift
@@ -174,8 +174,12 @@ extension ManagedBuffer where Element: ~Copyable {
 }
 
 extension ManagedBuffer {
+  @abi(
+    final func withUnsafeMutablePointerToHeader<R>(
+      _ body: (UnsafeMutablePointer<Header>) throws -> R
+    ) rethrows -> R
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss13ManagedBufferC32withUnsafeMutablePointerToHeaderyqd__qd__SpyxGKXEKlF")
   @usableFromInline
   internal final func __legacy_withUnsafeMutablePointerToHeader<R>(
     _ body: (UnsafeMutablePointer<Header>) throws -> R
@@ -183,8 +187,12 @@ extension ManagedBuffer {
     return try unsafe withUnsafeMutablePointers { (v, _) in return try unsafe body(v) }
   }
 
+  @abi(
+    final func withUnsafeMutablePointerToElements<R>(
+      _ body: (UnsafeMutablePointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss13ManagedBufferC34withUnsafeMutablePointerToElementsyqd__qd__Spyq_GKXEKlF")
   @usableFromInline
   internal final func __legacy_withUnsafeMutablePointerToElements<R>(
     _ body: (UnsafeMutablePointer<Element>) throws -> R
@@ -192,8 +200,14 @@ extension ManagedBuffer {
     return try unsafe withUnsafeMutablePointers { return try unsafe body($1) }
   }
 
+  @abi(
+    final func withUnsafeMutablePointers<R>(
+      _ body: (
+        UnsafeMutablePointer<Header>, UnsafeMutablePointer<Element>
+      ) throws -> R
+    ) rethrows -> R
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss13ManagedBufferC25withUnsafeMutablePointersyqd__qd__SpyxG_Spyq_GtKXEKlF")
   @usableFromInline
   internal final func __legacy_withUnsafeMutablePointers<R>(
     _ body: (
@@ -473,27 +487,41 @@ extension ManagedBufferPointer where Element: ~Copyable {
   }
 }
 
-extension ManagedBufferPointer {
+extension ManagedBufferPointer /* where Element: Copyable */ {
+  @abi(
+    func withUnsafeMutablePointerToHeader<R>(
+      _ body: (UnsafeMutablePointer<Header>) throws -> R
+    ) rethrows -> R
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss20ManagedBufferPointerV017withUnsafeMutableC8ToHeaderyqd__qd__SpyxGKXEKlF")
   @usableFromInline
-  internal func withUnsafeMutablePointerToHeader<R>(
+  internal func __rethrows_withUnsafeMutablePointerToHeader<R>(
     _ body: (UnsafeMutablePointer<Header>) throws -> R
   ) rethrows -> R {
     try unsafe withUnsafeMutablePointers { (v, _) in try unsafe body(v) }
   }
 
+  @abi(
+    func withUnsafeMutablePointerToElements<R>(
+      _ body: (UnsafeMutablePointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss20ManagedBufferPointerV017withUnsafeMutableC10ToElementsyqd__qd__Spyq_GKXEKlF")
   @usableFromInline
-  internal func withUnsafeMutablePointerToElements<R>(
+  internal func __rethrows_withUnsafeMutablePointerToElements<R>(
     _ body: (UnsafeMutablePointer<Element>) throws -> R
   ) rethrows -> R {
     try unsafe withUnsafeMutablePointers { (_, v) in try unsafe body(v) }
   }
 
+  @abi(
+    func withUnsafeMutablePointers<R>(
+      _ body: (
+        UnsafeMutablePointer<Header>, UnsafeMutablePointer<Element>
+      ) throws -> R
+    ) rethrows -> R
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss20ManagedBufferPointerV25withUnsafeMutablePointersyqd__qd__SpyxG_Spyq_GtKXEKlF")
   @usableFromInline
   internal func withUnsafeMutablePointers<R>(
     _ body: (
diff --git a/stdlib/public/core/Optional.swift b/stdlib/public/core/Optional.swift
index f7614db294703..d70b063b156b8 100644
--- a/stdlib/public/core/Optional.swift
+++ b/stdlib/public/core/Optional.swift
@@ -848,10 +848,15 @@ public func ?? <T: ~Copyable>(
   }
 }
 
+@abi(
+  func ?? <T>(
+    optional: T?,
+    defaultValue: @autoclosure () throws -> T
+  ) rethrows -> T
+)
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss2qqoiyxxSg_xyKXKtKlF")
 @usableFromInline
-internal func _legacy_abi_optionalNilCoalescingOperator <T>(
+internal func _copyable_optionalNilCoalescingOperator <T>(
   optional: T?,
   defaultValue: @autoclosure () throws -> T
 ) rethrows -> T {
@@ -924,9 +929,15 @@ public func ?? <T: ~Copyable>(
   }
 }
 
+@abi(
+  func ?? <T>(
+    optional: T?,
+    defaultValue: @autoclosure () throws -> T?
+  ) rethrows -> T?
+)
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
 @usableFromInline
-internal func ?? <T>(
+internal func _copyable_optionalNilCoalescingOperator <T>(
   optional: T?,
   defaultValue: @autoclosure () throws -> T?
 ) rethrows -> T? {
diff --git a/stdlib/public/core/Result.swift b/stdlib/public/core/Result.swift
index 4d5c8fc58c6ff..af48cb9a4226e 100644
--- a/stdlib/public/core/Result.swift
+++ b/stdlib/public/core/Result.swift
@@ -67,10 +67,14 @@ extension Result {
 }
 
 extension Result {
+  @abi(
+    func map<NewSuccess>(
+      _ transform: (Success) -> NewSuccess
+    ) -> Result<NewSuccess, Failure>
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss6ResultO3mapyAByqd__q_Gqd__xXElF")
   @usableFromInline
-  internal func __abi_map<NewSuccess>(
+  internal func __copyable_map<NewSuccess>(
     _ transform: (Success) -> NewSuccess
   ) -> Result<NewSuccess, Failure> {
     switch self {
@@ -210,10 +214,14 @@ extension Result {
 }
 
 extension Result {
+  @abi(
+    func flatMap<NewSuccess>(
+      _ transform: (Success) -> Result<NewSuccess, Failure>
+    ) -> Result<NewSuccess, Failure>
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss6ResultO7flatMapyAByqd__q_GADxXElF")
   @usableFromInline
-  internal func __abi_flatMap<NewSuccess>(
+  internal func __copyable_flatMap<NewSuccess>(
     _ transform: (Success) -> Result<NewSuccess, Failure>
   ) -> Result<NewSuccess, Failure> {
     switch self {
@@ -278,10 +286,14 @@ extension Result where Success: ~Copyable {
 }
 
 extension Result {
+  @abi(
+    func flatMapError<NewFailure>(
+      _ transform: (Failure) -> Result<Success, NewFailure>
+    ) -> Result<Success, NewFailure>
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss6ResultO12flatMapErroryAByxqd__GADq_XEs0D0Rd__lF")
   @usableFromInline
-  internal func __abi_flatMapError<NewFailure>(
+  internal func __copyable_flatMapError<NewFailure>(
     _ transform: (Failure) -> Result<Success, NewFailure>
   ) -> Result<Success, NewFailure> {
     switch self {
@@ -324,10 +336,10 @@ extension Result where Success: ~Copyable & ~Escapable {
 
 extension Result {
   /// ABI: Historical get() throws
+  @abi(func get() throws -> Success)
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss6ResultO3getxyKF")
   @usableFromInline
-  func __abi_get() throws -> Success {
+  func __untyped_throws_get() throws -> Success {
     switch self {
     case let .success(success):
       return success
@@ -355,11 +367,12 @@ extension Result where Success: ~Copyable {
 }
 
 extension Result where Failure == Swift.Error {
-  /// ABI: Historical init(catching:)
+  // ABI: Historical `init(catching:)`; this gets the old ABI because of the
+  // `where` clause on the extension.
+  @abi(init(catching body: () throws -> Success))
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$ss6ResultOss5Error_pRs_rlE8catchingAByxsAC_pGxyKXE_tcfC")
   @usableFromInline
-  init(__abi_catching body: () throws(Failure) -> Success) {
+  init(__untyped_throws_catching body: () throws(Failure) -> Success) {
     do {
       self = .success(try body())
     } catch {
diff --git a/stdlib/public/core/Sequence.swift b/stdlib/public/core/Sequence.swift
index e34bb9d8df267..43f8f72e3df20 100644
--- a/stdlib/public/core/Sequence.swift
+++ b/stdlib/public/core/Sequence.swift
@@ -706,11 +706,14 @@ extension Sequence {
   }
 
   // ABI-only entrypoint for the rethrows version of map, which has been
-  // superseded by the typed-throws version. Expressed as "throws", which is
-  // ABI-compatible with "rethrows".
+  // superseded by the typed-throws version.
+  @abi(
+    func map<T>(
+      _ transform: (Element) throws -> T
+    ) rethrows -> [T]
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
   @usableFromInline
-  @_silgen_name("$sSTsE3mapySayqd__Gqd__7ElementQzKXEKlF")
   func __rethrows_map<T>(
     _ transform: (Element) throws -> T
   ) throws -> [T] {
diff --git a/stdlib/public/core/SliceBuffer.swift b/stdlib/public/core/SliceBuffer.swift
index ba4956fdbab0d..237da627920b6 100644
--- a/stdlib/public/core/SliceBuffer.swift
+++ b/stdlib/public/core/SliceBuffer.swift
@@ -433,9 +433,13 @@ internal struct _SliceBuffer<Element>
   //===--- misc -----------------------------------------------------------===//
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
+  @abi(
+    func withUnsafeBufferPointer<R>(
+      _ body: (UnsafeBufferPointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @usableFromInline
-  @_silgen_name("$ss12_SliceBufferV010withUnsafeB7Pointeryqd__qd__SRyxGKXEKlF")
-  internal func __abi_withUnsafeBufferPointer<R>(
+  internal func __rethrows_withUnsafeBufferPointer<R>(
     _ body: (UnsafeBufferPointer<Element>) throws -> R
   ) rethrows -> R {
     defer { _fixLifetime(self) }
@@ -456,9 +460,13 @@ internal struct _SliceBuffer<Element>
 
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
+  @abi(
+    mutating func withUnsafeMutableBufferPointer<R>(
+      _ body: (UnsafeMutableBufferPointer<Element>) throws -> R
+    ) rethrows -> R
+  )
   @usableFromInline
-  @_silgen_name("$ss12_SliceBufferV017withUnsafeMutableB7Pointeryqd__qd__SryxGKXEKlF")
-  internal mutating func __abi_withUnsafeMutableBufferPointer<R>(
+  internal mutating func __rethrows_withUnsafeMutableBufferPointer<R>(
     _ body: (UnsafeMutableBufferPointer<Element>) throws -> R
   ) rethrows -> R {
     defer { _fixLifetime(self) }
diff --git a/stdlib/public/core/UnsafeBufferPointer.swift.gyb b/stdlib/public/core/UnsafeBufferPointer.swift.gyb
index ca385ef259525..98b9c313749d0 100644
--- a/stdlib/public/core/UnsafeBufferPointer.swift.gyb
+++ b/stdlib/public/core/UnsafeBufferPointer.swift.gyb
@@ -937,8 +937,13 @@ extension UnsafeMutableBufferPointer {
   ///   buffer.
   /// - Returns: An iterator to any elements of `source` that didn't fit in the
   ///   buffer, and an index to the next uninitialized element in the buffer.
+  @abi(
+    func initialize<S: Sequence>(
+      from source: S
+    ) -> (/* not 'unwritten:' */ S.Iterator, /* not 'index:' */ Index)
+      where S.Element == Element
+  )
   @inlinable // unsafe-performance
-  @_silgen_name("$sSr10initialize4from8IteratorQyd___Sitqd___t7ElementQyd__RszSTRd__lF")
   public func initialize<S: Sequence>(
     from source: S
   ) -> (unwritten: S.Iterator, index: Index) where S.Element == Element {
@@ -1009,8 +1014,8 @@ extension UnsafeMutableBufferPointer {
   ///
   /// - Parameters:
   ///   - repeatedValue: The value used when updating this pointer's memory.
+  @abi(func assign(repeating repeatedValue: Element))
   @inlinable // unsafe-performance
-  @_silgen_name("$sSr6assign9repeatingyx_tF")
   public func update(repeating repeatedValue: Element) {
     guard let dstBase = _position else {
       return
@@ -1019,9 +1024,9 @@ extension UnsafeMutableBufferPointer {
     unsafe dstBase.update(repeating: repeatedValue, count: count)
   }
 
+  @abi(func update(repeating repeatedValue: Element))
   @_alwaysEmitIntoClient
   @available(*, deprecated, renamed: "update(repeating:)")
-  @_silgen_name("_swift_se0370_UnsafeMutableBufferPointer_assign_repeating")
   public func assign(repeating repeatedValue: Element) {
     unsafe update(repeating: repeatedValue)
   }
@@ -1431,12 +1436,13 @@ extension Unsafe${Mutable}BufferPointer {
   // of `withMemoryRebound<T, Result>(to:_:)`, and provides
   // an entry point for any binary linked against the stdlib binary
   // for Swift 5.6 and older.
+  @abi(
+    func withMemoryRebound<T, Result>(
+      to type: T.Type,
+      _ body: (${Self}<T>) throws -> Result
+    ) rethrows -> Result
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-% if Mutable:
-  @_silgen_name("$sSr17withMemoryRebound2to_qd_0_qd__m_qd_0_Sryqd__GKXEtKr0_lF")
-% else:
-  @_silgen_name("$sSR17withMemoryRebound2to_qd_0_qd__m_qd_0_SRyqd__GKXEtKr0_lF")
-% end
   @usableFromInline
   internal func _legacy_se0333_withMemoryRebound<T, Result>(
     to type: T.Type,
diff --git a/stdlib/public/core/UnsafePointer.swift b/stdlib/public/core/UnsafePointer.swift
index db53ea3a0e57b..54db6a18e280e 100644
--- a/stdlib/public/core/UnsafePointer.swift
+++ b/stdlib/public/core/UnsafePointer.swift
@@ -421,8 +421,14 @@ extension UnsafePointer {
   // of `withMemoryRebound<T, Result>(to:capacity:_:)`, and provides
   // an entry point for any binary linked against the stdlib binary
   // for Swift 5.6 and older.
+  @abi(
+    func withMemoryRebound<T, Result>(
+      to type: T.Type,
+      capacity count: Int,
+      _ body: (UnsafePointer<T>) throws -> Result
+    ) rethrows -> Result
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$sSP17withMemoryRebound2to8capacity_qd_0_qd__m_Siqd_0_SPyqd__GKXEtKr0_lF")
   @usableFromInline
   internal func _legacy_se0333_withMemoryRebound<T, Result>(
     to type: T.Type,
@@ -954,8 +960,8 @@ extension UnsafeMutablePointer {
   ///   - repeatedValue: The value used when updating this pointer's memory.
   ///   - count: The number of consecutive elements to update.
   ///     `count` must not be negative.
+  @abi(func assign(repeating repeatedValue: Pointee, count: Int))
   @inlinable
-  @_silgen_name("$sSp6assign9repeating5countyx_SitF")
   public func update(repeating repeatedValue: Pointee, count: Int) {
     _debugPrecondition(count >= 0, "UnsafeMutablePointer.update(repeating:count:) with negative count")
     for i in 0..<count {
@@ -963,9 +969,9 @@ extension UnsafeMutablePointer {
     }
   }
 
+  @abi(func update(repeating repeatedValue: Pointee, count: Int))
   @_alwaysEmitIntoClient
   @available(*, deprecated, renamed: "update(repeating:count:)")
-  @_silgen_name("_swift_se0370_UnsafeMutablePointer_assign_repeating_count")
   public func assign(repeating repeatedValue: Pointee, count: Int) {
     unsafe update(repeating: repeatedValue, count: count)
   }
@@ -988,8 +994,8 @@ extension UnsafeMutablePointer {
   ///     pointer may overlap.
   ///   - count: The number of instances to copy from the memory referenced by
   ///     `source` to this pointer's memory. `count` must not be negative.
+  @abi(func assign(from source: UnsafePointer<Pointee>, count: Int))
   @inlinable
-  @_silgen_name("$sSp6assign4from5countySPyxG_SitF")
   public func update(from source: UnsafePointer<Pointee>, count: Int) {
     _debugPrecondition(
       count >= 0, "UnsafeMutablePointer.update with negative count")
@@ -1015,9 +1021,9 @@ extension UnsafeMutablePointer {
     }
   }
 
+  @abi(func update(from source: UnsafePointer<Pointee>, count: Int))
   @_alwaysEmitIntoClient
   @available(*, deprecated, renamed: "update(from:count:)")
-  @_silgen_name("_swift_se0370_UnsafeMutablePointer_assign_from_count")
   @unsafe
   public func assign(from source: UnsafePointer<Pointee>, count: Int) {
     unsafe update(from: source, count: count)
@@ -1126,8 +1132,13 @@ extension UnsafeMutablePointer where Pointee: ~Copyable {
   ///     referenced by `source` and this pointer must not overlap.
   ///   - count: The number of instances to move from `source` to this
   ///     pointer's memory. `count` must not be negative.
+  @abi(
+    @_preInverseGenerics
+    func moveAssign(
+      from source: UnsafeMutablePointer, count: Int
+    )
+  )
   @inlinable
-  @_silgen_name("$sSp10moveAssign4from5countySpyxG_SitF")
   @_preInverseGenerics
   public func moveUpdate(
     @_nonEphemeral from source: UnsafeMutablePointer, count: Int
@@ -1147,9 +1158,13 @@ extension UnsafeMutablePointer where Pointee: ~Copyable {
 }
 
 extension UnsafeMutablePointer {
+  @abi(
+    func moveUpdate(
+      from source: UnsafeMutablePointer, count: Int
+    )
+  )
   @_alwaysEmitIntoClient
   @available(*, deprecated, renamed: "moveUpdate(from:count:)")
-  @_silgen_name("_swift_se0370_UnsafeMutablePointer_moveAssign_from_count")
   public func moveAssign(
     @_nonEphemeral from source: UnsafeMutablePointer, count: Int
   ) {
@@ -1268,8 +1283,14 @@ extension UnsafeMutablePointer {
   // This obsolete implementation uses the expected mangled name of
   // `withMemoryRebound<T, Result>(to:capacity:_:)`, and provides an entry point
   // for any binary linked against the stdlib binary for Swift 5.6 and older.
+  @abi(
+    func withMemoryRebound<T, Result>(
+      to type: T.Type,
+      capacity count: Int,
+      _ body: (UnsafeMutablePointer<T>) throws -> Result
+    ) rethrows -> Result
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$sSp17withMemoryRebound2to8capacity_qd_0_qd__m_Siqd_0_Spyqd__GKXEtKr0_lF")
   @usableFromInline
   internal func _legacy_se0333_withMemoryRebound<T, Result>(
     to type: T.Type,
diff --git a/stdlib/public/core/UnsafeRawBufferPointer.swift.gyb b/stdlib/public/core/UnsafeRawBufferPointer.swift.gyb
index 2ee50c1b77af2..3d88b66173d19 100644
--- a/stdlib/public/core/UnsafeRawBufferPointer.swift.gyb
+++ b/stdlib/public/core/UnsafeRawBufferPointer.swift.gyb
@@ -504,9 +504,13 @@ extension Unsafe${Mutable}RawBufferPointer {
   ///   - type: The type to use for the newly constructed instance. The memory
   ///     must be initialized to a value of a type that is layout compatible
   ///     with `type`.
+  @abi(
+    // This is chosen to not interfere with the old ABI
+    func _new_se0349_storeBytes<T>(
+      of value: T, toByteOffset offset: Int, as type: T.Type
+    )
+  )
   @_alwaysEmitIntoClient
-  // This custom silgen name is chosen to not interfere with the old ABI
-  @_silgen_name("_swift_se0349_UnsafeMutableRawBufferPointer_storeBytes")
   public func storeBytes<T>(
     of value: T, toByteOffset offset: Int = 0, as type: T.Type
   ) {
@@ -521,8 +525,12 @@ extension Unsafe${Mutable}RawBufferPointer {
   // This unavailable implementation uses the expected mangled name
   // of `storeBytes<T>(of:toByteOffset:as:)`, and provides an entry point for
   // any binary linked against the stdlib binary for Swift 5.6 and older.
+  @abi(
+    func storeBytes<T>(
+      of value: T, toByteOffset offset: Int, as type: T.Type
+    )
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$sSw10storeBytes2of12toByteOffset2asyx_SixmtlF")
   @usableFromInline
   func _legacy_se0349_storeBytes<T>(
     of value: T, toByteOffset offset: Int = 0, as type: T.Type
@@ -1245,10 +1253,14 @@ public func withUnsafeMutableBytes<T: ~Copyable, E: Error, Result: ~Copyable>(
   return try unsafe body(unsafe .init(start: pointer, count: MemoryLayout<T>.size))
 }
 
-/// ABI: Historical withUnsafeMutableBytes(of:_:) rethrows,
-/// expressed as "throws", which is ABI-compatible with "rethrows".
+/// ABI: Historical withUnsafeMutableBytes(of:_:) rethrows.
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss22withUnsafeMutableBytes2of_q_xz_q_SwKXEtKr0_lF")
+@abi(
+  func withUnsafeMutableBytes<T, Result>(
+    of value: inout T,
+    _ body: (UnsafeMutableRawBufferPointer) throws -> Result
+  ) rethrows -> Result
+)
 @usableFromInline
 func __abi_se0413_withUnsafeMutableBytes<T, Result>(
   of value: inout T,
@@ -1312,10 +1324,14 @@ public func withUnsafeBytes<T: ~Copyable, E: Error, Result: ~Copyable>(
   return try unsafe body(unsafe .init(start: address, count: MemoryLayout<T>.size))
 }
 
-/// ABI: Historical withUnsafeBytes(of:_:) rethrows,
-/// expressed as "throws", which is ABI-compatible with "rethrows".
+/// ABI: Historical withUnsafeBytes(of:_:) rethrows.
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss15withUnsafeBytes2of_q_xz_q_SWKXEtKr0_lF")
+@abi(
+  func withUnsafeBytes<T, Result>(
+    of value: inout T,
+    _ body: (UnsafeRawBufferPointer) throws -> Result
+  ) rethrows -> Result
+)
 @usableFromInline
 func __abi_se0413_withUnsafeBytes<T, Result>(
   of value: inout T,
@@ -1379,7 +1395,12 @@ public func withUnsafeBytes<
 /// ABI: Historical withUnsafeBytes(of:_:) rethrows,
 /// expressed as "throws", which is ABI-compatible with "rethrows".
 @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-@_silgen_name("$ss15withUnsafeBytes2of_q_x_q_SWKXEtKr0_lF")
+@abi(
+  func withUnsafeBytes<T, Result>(
+    of value: T,
+    _ body: (UnsafeRawBufferPointer) throws -> Result
+  ) throws -> Result
+)
 @usableFromInline
 func __abi_se0413_withUnsafeBytes<T, Result>(
   of value: T,
diff --git a/stdlib/public/core/UnsafeRawPointer.swift b/stdlib/public/core/UnsafeRawPointer.swift
index f3c4d16e04380..f1984890eacd5 100644
--- a/stdlib/public/core/UnsafeRawPointer.swift
+++ b/stdlib/public/core/UnsafeRawPointer.swift
@@ -1457,10 +1457,14 @@ extension UnsafeMutableRawPointer {
   ///   - offset: The offset from this pointer, in bytes. `offset` must be
   ///     nonnegative. The default is zero.
   ///   - type: The type of `value`.
+  @abi(
+    // This custom ABI is chosen to not interfere with the old ABI
+    func _new_se0349_storeBytes<T>(
+      of value: T, toByteOffset offset: Int, as type: T.Type
+    )
+  )
   @inlinable
   @_alwaysEmitIntoClient
-  // This custom silgen name is chosen to not interfere with the old ABI
-  @_silgen_name("_swift_se0349_UnsafeMutableRawPointer_storeBytes")
   public func storeBytes<T>(
     of value: T, toByteOffset offset: Int = 0, as type: T.Type
   ) {
@@ -1483,8 +1487,12 @@ extension UnsafeMutableRawPointer {
   // This obsolete implementation uses the expected mangled name
   // of `storeBytes<T>(of:toByteOffset:as:)`, and provides an entry point for
   // any binary compiled against the stdlib binary for Swift 5.6 and older.
+  @abi(
+    func storeBytes<T>(
+      of value: T, toByteOffset offset: Int, as type: T.Type
+    )
+  )
   @_spi(SwiftStdlibLegacyABI) @available(swift, obsoleted: 1)
-  @_silgen_name("$sSv10storeBytes2of12toByteOffset2asyx_SixmtlF")
   @usableFromInline
   func _legacy_se0349_storeBytes<T>(
     of value: T, toByteOffset offset: Int = 0, as type: T.Type
diff --git a/test/Macros/macro_expand.swift b/test/Macros/macro_expand.swift
index 08c8c008cc059..cd1980c6f998c 100644
--- a/test/Macros/macro_expand.swift
+++ b/test/Macros/macro_expand.swift
@@ -1,23 +1,24 @@
 // REQUIRES: swift_swift_parser, executable_test
+// REQUIRES: swift_feature_ABIAttribute
 
 // RUN: %empty-directory(%t)
 // RUN: %host-build-swift -swift-version 5 -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift
 
 // Diagnostics testing
-// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS
+// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -enable-experimental-feature ABIAttribute
 
 // Diagnostics testing by importing macros from a module
 // RUN: %target-swift-frontend -swift-version 5 -emit-module -o %t/freestanding_macro_library.swiftmodule %S/Inputs/freestanding_macro_library.swift -module-name freestanding_macro_library -load-plugin-library %t/%target-library-name(MacroDefinition)
 // RUN: %target-swift-frontend -swift-version 5 -emit-module -o %t/freestanding_macro_library_2.swiftmodule %S/Inputs/freestanding_macro_library_2.swift -module-name freestanding_macro_library_2 -load-plugin-library %t/%target-library-name(MacroDefinition) -I %t
 
-// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -I %t -DIMPORT_MACRO_LIBRARY
+// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -I %t -DIMPORT_MACRO_LIBRARY -enable-experimental-feature ABIAttribute
 
-// RUN: not %target-swift-frontend -swift-version 5 -typecheck -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -serialize-diagnostics-path %t/macro_expand.dia %s -emit-macro-expansion-files no-diagnostics -Rmacro-loading > %t/macro-printing.txt
+// RUN: not %target-swift-frontend -swift-version 5 -typecheck -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -serialize-diagnostics-path %t/macro_expand.dia %s -emit-macro-expansion-files no-diagnostics -Rmacro-loading > %t/macro-printing.txt -enable-experimental-feature ABIAttribute
 // RUN: c-index-test -read-diagnostics %t/macro_expand.dia 2>&1 | %FileCheck -check-prefix CHECK-DIAGS -dump-input=always %s
 
 // RUN: %FileCheck %s  --check-prefix CHECK-MACRO-PRINTED < %t/macro-printing.txt
 
-// RUN: not %target-swift-frontend -swift-version 5 -typecheck -diagnostic-style=swift -load-plugin-library %t/%target-library-name(MacroDefinition)  -module-name MacroUser -DTEST_DIAGNOSTICS %s > %t/pretty-macro-diagnostics.txt 2>&1
+// RUN: not %target-swift-frontend -swift-version 5 -typecheck -diagnostic-style=swift -load-plugin-library %t/%target-library-name(MacroDefinition)  -module-name MacroUser -DTEST_DIAGNOSTICS %s -enable-experimental-feature ABIAttribute > %t/pretty-macro-diagnostics.txt 2>&1
 // RUN: %FileCheck %s --check-prefix PRETTY-DIAGS < %t/pretty-macro-diagnostics.txt
 
 // Debug info SIL testing
@@ -707,6 +708,29 @@ func testPropertyWrapperMacro() {
   #hasPropertyWrapperParam($x: .init(wrappedValue: 0))
 }
 
+#if swift(>=1.0) && TEST_DIAGNOSTICS
+// Test that macros can't be used in @abi
+
+struct ABIAttrWithFreestandingMacro1 {
+  // expected-error@+1 {{cannot use pound literal in '@abi'}}
+  @abi(#varValue)
+  #varValue
+  // expected-note@-1 {{in expansion of macro 'varValue' here}}
+}
+
+struct ABIAttrWithFreestandingMacro2 {
+  // expected-error@+1 {{cannot use pound literal in '@abi'}}
+  @abi(#varValue)
+  var value: Int { 0 }
+}
+
+struct ABIAttrWithFreestandingMacro3 {
+  @abi(var value: Int)
+  #varValue
+}
+
+#endif
+
 #if TEST_DIAGNOSTICS
 @freestanding(expression)
 macro missingMacro() = #externalMacro(module: "MacroDefinition", type: "BluhBlah")
diff --git a/test/Macros/macro_expand_peers.swift b/test/Macros/macro_expand_peers.swift
index 99f8febe7fe7f..6f866a6ffd753 100644
--- a/test/Macros/macro_expand_peers.swift
+++ b/test/Macros/macro_expand_peers.swift
@@ -1,4 +1,5 @@
 // REQUIRES: swift_swift_parser, executable_test
+// REQUIRES: swift_feature_ABIAttribute
 
 // For _Concurrency.
 // UNSUPPORTED: use_os_stdlib
@@ -6,12 +7,12 @@
 
 // RUN: %empty-directory(%t)
 // RUN: %host-build-swift -swift-version 5 -emit-library -o %t/%target-library-name(MacroDefinition) -parse-as-library -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath
-// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -parse-as-library -disable-availability-checking -DTEST_DIAGNOSTICS
+// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -parse-as-library -disable-availability-checking -enable-experimental-feature ABIAttribute -DTEST_DIAGNOSTICS
 
 // Check with the imported macro library vs. the local declaration of the macro.
 // RUN: %target-swift-frontend -swift-version 5 -emit-module -o %t/macro_library.swiftmodule %S/Inputs/macro_library.swift -module-name macro_library -load-plugin-library %t/%target-library-name(MacroDefinition)
 
-// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -parse-as-library -disable-availability-checking -DIMPORT_MACRO_LIBRARY -I %t -DTEST_DIAGNOSTICS
+// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -parse-as-library -disable-availability-checking -DIMPORT_MACRO_LIBRARY -I %t -enable-experimental-feature ABIAttribute -DTEST_DIAGNOSTICS
 
 
 // RUN: %target-swift-frontend -swift-version 5 -typecheck -load-plugin-library %t/%target-library-name(MacroDefinition) -parse-as-library %s -disable-availability-checking -dump-macro-expansions > %t/expansions-dump.txt 2>&1
@@ -309,3 +310,26 @@ func closuresInPeerMacroCrash() {}
 @trait(Trait {})
 @trait(Trait {})
 var closuresInPeerMacroOnVariableCrash: Int = 0
+
+// Test that macros can't be used in @abi
+
+#if TEST_DIAGNOSTICS
+struct ABIAttrWithAttachedMacro {
+  // expected-error@+1 {{macro 'addCompletionHandler()' cannot be expanded in '@abi' attribute}}
+  @abi(@addCompletionHandler func fn1() async)
+  @addCompletionHandler func fn1() async {}
+  // From diagnostics in the expansion:
+  // expected-note@-2 3{{in expansion of macro 'addCompletionHandler' on instance method 'fn1()' here}}
+  // expected-note@-4 {{'fn1()' previously declared here}}
+
+  // expected-error@+1 {{macro 'addCompletionHandler()' cannot be expanded in '@abi' attribute}}
+  @abi(@addCompletionHandler func fn2() async)
+  func fn2() async {}
+
+  @abi(func fn3() async)
+  @addCompletionHandler func fn3() async {}
+  // From diagnostics in the expansion:
+  // expected-note@-2 2{{in expansion of macro 'addCompletionHandler' on instance method 'fn3()' here}}
+  // expected-note@-4 {{'fn3()' previously declared here}}
+}
+#endif
diff --git a/test/api-digester/Outputs/stability-stdlib-source-base.swift.expected b/test/api-digester/Outputs/stability-stdlib-source-base.swift.expected
index 131ce99fa0cfb..cd0df7f8c1205 100644
--- a/test/api-digester/Outputs/stability-stdlib-source-base.swift.expected
+++ b/test/api-digester/Outputs/stability-stdlib-source-base.swift.expected
@@ -375,3 +375,15 @@ Accessor UnsafeMutableBufferPointer.indices.Get() has generic signature change f
 
 Func type(of:) has generic signature change from <T, Metatype> to <T, Metatype where T : ~Copyable, T : ~Escapable>
 Func type(of:) has parameter 0 changing from Default to Shared
+
+// Renames made by SE-0370. There are also new deprecated methods to preserve
+// source compatibility. These only started being flagged when the ABI magic
+// switched from @_silgen_name to @abi.
+Func UnsafeMutableBufferPointer.assign(repeating:) has been renamed to Func update(repeating:)
+Func UnsafeMutablePointer.assign(from:count:) has been renamed to Func update(from:count:)
+Func UnsafeMutablePointer.assign(repeating:count:) has been renamed to Func update(repeating:count:)
+
+// False positive: this is a new overload of a method with some @abi trickery
+// that confuses the API checker into losing track of the old overload.
+// FIXME: It'd be nice if this didn't happen.
+Func UnsafeMutableRawPointer.storeBytes(of:toByteOffset:as:) has generic signature change from <T> to <T where T : Swift.BitwiseCopyable>
diff --git a/test/api-digester/stability-concurrency-abi.test b/test/api-digester/stability-concurrency-abi.test
index 3625780b555bf..cfc285aff877b 100644
--- a/test/api-digester/stability-concurrency-abi.test
+++ b/test/api-digester/stability-concurrency-abi.test
@@ -80,24 +80,13 @@ Protocol Executor has added inherited protocol SendableMetatype
 Protocol SerialExecutor has added inherited protocol SendableMetatype
 
 // #isolated adoption in with...Continuation
-// api-digester is not aware of silgen_name trickery we do to keep this ABI compatible
-Func withCheckedContinuation(function:_:) has parameter 0 type change from Swift.String to (any _Concurrency.Actor)?
-Func withCheckedContinuation(function:_:) has parameter 1 type change from (_Concurrency.CheckedContinuation<τ_0_0, Swift.Never>) -> () to Swift.String
-Func withCheckedThrowingContinuation(function:_:) has been renamed to Func withCheckedThrowingContinuation(isolation:function:_:)
-Func withCheckedThrowingContinuation(function:_:) has mangled name changing from '_Concurrency.withCheckedThrowingContinuation<A>(function: Swift.String, _: (Swift.CheckedContinuation<A, Swift.Error>) -> ()) async throws -> A' to '_Concurrency.withCheckedThrowingContinuation<A>(isolation: isolated Swift.Optional<Swift.Actor>, function: Swift.String, _: (Swift.CheckedContinuation<A, Swift.Error>) -> ()) async throws -> A'
-Func withCheckedThrowingContinuation(function:_:) has parameter 0 type change from Swift.String to (any _Concurrency.Actor)?
-Func withCheckedThrowingContinuation(function:_:) has parameter 1 type change from (_Concurrency.CheckedContinuation<τ_0_0, any Swift.Error>) -> () to Swift.String
+// There are new @_alwaysEmitIntoClient functions to preserve source compatibility
+Func withCheckedContinuation(function:_:) has been renamed to Func _unsafeInheritExecutor_withCheckedContinuation(function:_:)
+Func withCheckedThrowingContinuation(function:_:) has been renamed to Func _unsafeInheritExecutor_withCheckedThrowingContinuation(function:_:)
 
 // #isolation adoption for cancellation handlers; old APIs are kept ABI compatible
-Func withTaskCancellationHandler(operation:onCancel:) has been renamed to Func withTaskCancellationHandler(operation:onCancel:isolation:)
-Func withTaskCancellationHandler(operation:onCancel:) has mangled name changing from '_Concurrency.withTaskCancellationHandler<A>(operation: () async throws -> A, onCancel: @Sendable () -> ()) async throws -> A' to '_Concurrency.withTaskCancellationHandler<A>(operation: () async throws -> A, onCancel: @Sendable () -> (), isolation: isolated Swift.Optional<Swift.Actor>) async throws -> A'
-
-// #isolated was adopted and the old methods kept: $ss31withCheckedThrowingContinuation8function_xSS_yScCyxs5Error_pGXEtYaKlF
-Func withCheckedContinuation(function:_:) has been renamed to Func withCheckedContinuation(isolation:function:_:)
-Func withCheckedContinuation(function:_:) has mangled name changing from '_Concurrency.withCheckedContinuation<A>(function: Swift.String, _: (Swift.CheckedContinuation<A, Swift.Never>) -> ()) async -> A' to '_Concurrency.withCheckedContinuation<A>(isolation: isolated Swift.Optional<Swift.Actor>, function: Swift.String, _: (Swift.CheckedContinuation<A, Swift.Never>) -> ()) async -> A'
-
-// AsyncStream.init(unfolding:onCancel:) uses @_silgen_name to preserve mangling after adding @preconcurrency.
-Constructor AsyncStream.init(unfolding:onCancel:) has mangled name changing from 'Swift.AsyncStream.init(unfolding: () async -> Swift.Optional<A>, onCancel: Swift.Optional<@Sendable () -> ()>) -> Swift.AsyncStream<A>' to 'Swift.AsyncStream.init(unfolding: () async -> Swift.Optional<A>, onCancel: Swift.Optional<() -> ()>) -> Swift.AsyncStream<A>'
+// There's a new @_alwaysEmitIntoClient function to preserve source compatibility
+Func withTaskCancellationHandler(operation:onCancel:) has been renamed to Func _unsafeInheritExecutor_withTaskCancellationHandler(operation:onCancel:)
 
 // We did not change the mangling, we did change from Default to Shared. Both
 // took their arg at +0, so there is no actual ABI difference.
@@ -114,13 +103,7 @@ Func SerialExecutor.enqueue(_:) has been added as a protocol requirement
 Func Executor.enqueue(_:) is a new API without @available attribute
 
 // Adopt #isolation in TaskLocal.withValue APIs
-Func TaskLocal.withValue(_:operation:file:line:) has been renamed to Func withValue(_:operation:isolation:file:line:)
-Func TaskLocal.withValue(_:operation:file:line:) has mangled name changing from '_Concurrency.TaskLocal.withValue<A>(_: A, operation: () async throws -> A1, file: Swift.String, line: Swift.UInt) async throws -> A1' to '_Concurrency.TaskLocal.withValue<A>(_: A, operation: () throws -> A1, file: Swift.String, line: Swift.UInt) throws -> A1'
-Func TaskLocal.withValue(_:operation:file:line:) has mangled name changing from '_Concurrency.TaskLocal.withValue<A>(_: A, operation: () throws -> A1, file: Swift.String, line: Swift.UInt) throws -> A1' to '_Concurrency.TaskLocal.withValue<A>(_: A, operation: () async throws -> A1, isolation: isolated Swift.Optional<Swift.Actor>, file: Swift.String, line: Swift.UInt) async throws -> A1'
-Func TaskLocal.withValue(_:operation:file:line:) has parameter 1 type change from () async throws -> τ_1_0 to () throws -> τ_1_0
-Func TaskLocal.withValue(_:operation:file:line:) has parameter 1 type change from () throws -> τ_1_0 to () async throws -> τ_1_0
-Func TaskLocal.withValue(_:operation:file:line:) has parameter 2 type change from Swift.String to (any _Concurrency.Actor)?
-Func TaskLocal.withValue(_:operation:file:line:) has parameter 3 type change from Swift.UInt to Swift.String
+Func TaskLocal.withValue(_:operation:file:line:) has been renamed to Func _unsafeInheritExecutor_withValue(_:operation:file:line:)
 Func withTaskGroup(of:returning:body:) has parameter 2 type change from (inout _Concurrency.TaskGroup<τ_0_0>) async -> τ_0_1 to (any _Concurrency.Actor)?
 Func withThrowingTaskGroup(of:returning:body:) has been renamed to Func withThrowingTaskGroup(of:returning:isolation:body:)
 Func withThrowingTaskGroup(of:returning:body:) has mangled name changing from '_Concurrency.withThrowingTaskGroup<A, B where A: Swift.Sendable>(of: A.Type, returning: B.Type, body: (inout Swift.ThrowingTaskGroup<A, Swift.Error>) async throws -> B) async throws -> B' to '_Concurrency.withThrowingTaskGroup<A, B where A: Swift.Sendable>(of: A.Type, returning: B.Type, isolation: isolated Swift.Optional<Swift.Actor>, body: (inout Swift.ThrowingTaskGroup<A, Swift.Error>) async throws -> B) async throws -> B'
@@ -128,6 +111,11 @@ Func withThrowingTaskGroup(of:returning:body:) has parameter 2 type change from
 Func withTaskGroup(of:returning:body:) has been renamed to Func withTaskGroup(of:returning:isolation:body:)
 Func withTaskGroup(of:returning:body:) has mangled name changing from '_Concurrency.withTaskGroup<A, B where A: Swift.Sendable>(of: A.Type, returning: B.Type, body: (inout Swift.TaskGroup<A>) async -> B) async -> B' to '_Concurrency.withTaskGroup<A, B where A: Swift.Sendable>(of: A.Type, returning: B.Type, isolation: isolated Swift.Optional<Swift.Actor>, body: (inout Swift.TaskGroup<A>) async -> B) async -> B'
 
+// False ABI digester positive caused by replacement of @_silgen_name hack with
+// @abi; the USR isn't affected by @_silgen_name but is affected by @abi, so the
+// baseline has data in it that doesn't reflect the actual mangled name.
+Func ThrowingTaskGroup.nextResultForABI() has mangled name changing from 'Swift.ThrowingTaskGroup.nextResultForABI() async throws -> Swift.Optional<Swift.Result<A, B>>' to 'Swift.ThrowingTaskGroup.nextResult() async throws -> Swift.Optional<Swift.Result<A, B>>'
+
 // *** DO NOT DISABLE OR XFAIL THIS TEST. *** (See comment above.)
 
 
diff --git a/test/api-digester/stability-stdlib-abi-without-asserts.test b/test/api-digester/stability-stdlib-abi-without-asserts.test
index 1c502ec017541..591e1040138b6 100644
--- a/test/api-digester/stability-stdlib-abi-without-asserts.test
+++ b/test/api-digester/stability-stdlib-abi-without-asserts.test
@@ -84,7 +84,7 @@ Enum Never has added a conformance to an existing protocol Decodable
 Enum Never has added a conformance to an existing protocol Encodable
 Enum Never has added a conformance to an existing protocol Identifiable
 
-// These functions haven't actually changed ABI, but are using @_silgen_name tricks to maintain the old ABI while moving to typed throws.
+// These functions haven't actually changed ABI, but are using @abi tricks to maintain the old ABI while moving to typed throws.
 Func AnyBidirectionalCollection.map(_:) has been removed
 Func AnyCollection.map(_:) has been removed
 Func AnyRandomAccessCollection.map(_:) has been removed
@@ -92,14 +92,11 @@ Func AnySequence.map(_:) has been removed
 Func Collection.map(_:) has been removed
 Func Sequence.map(_:) has been removed
 Constructor Result.init(catching:) has been removed
-Func withoutActuallyEscaping(_:do:) has been renamed to Func __abi_withoutActuallyEscaping(_:do:)
-Func withoutActuallyEscaping(_:do:) has mangled name changing from 'Swift.withoutActuallyEscaping<A, B>(_: A, do: (A) throws -> B) throws -> B' to 'Swift.__abi_withoutActuallyEscaping<A, B>(_: A, do: (A) throws -> B) throws -> B'
+Func withoutActuallyEscaping(_:do:) has been renamed to Func __rethrows_withoutActuallyEscaping(_:do:)
 Func withoutActuallyEscaping(_:do:) is now without rethrows
-Func _openExistential(_:do:) has been renamed to Func __abi_openExistential(_:do:)
-Func _openExistential(_:do:) has mangled name changing from 'Swift._openExistential<A, B, C>(_: A, do: (B) throws -> C) throws -> C' to 'Swift.__abi_openExistential<A, B, C>(_: A, do: (B) throws -> C) throws -> C'
+Func _openExistential(_:do:) has been renamed to Func __rethrows_openExistential(_:do:)
 Func _openExistential(_:do:) is now without rethrows
 
-
 // These haven't actually been removed; they are simply marked unavailable.
 // This seems to be a false positive in the ABI checker. This is not an ABI
 // break because the symbols are still present, and is not a source break
@@ -129,25 +126,20 @@ Func _RandomAccessCollectionBox._map(_:) is now without rethrows
 Func _SequenceBox._map(_:) is now without rethrows
 Func UnsafeMutableRawBufferPointer.storeBytes(of:toByteOffset:as:) has been removed
 Func UnsafeMutableRawPointer.storeBytes(of:toByteOffset:as:) has been removed
-Func UnsafeMutableBufferPointer.assign(repeating:) has been removed
-Func UnsafeMutableBufferPointer.update(repeating:) is a new API without @available attribute
-Func UnsafeMutablePointer.assign(from:count:) has been removed
-Func UnsafeMutablePointer.update(from:count:) is a new API without @available attribute
-Func UnsafeMutablePointer.assign(repeating:count:) has been removed
-Func UnsafeMutablePointer.update(repeating:count:) is a new API without @available attribute
+Func UnsafeMutableBufferPointer.assign(repeating:) has been renamed to Func update(repeating:)
+Func UnsafeMutablePointer.assign(from:count:) has been renamed to Func update(from:count:)
+Func UnsafeMutablePointer.assign(repeating:count:) has been renamed to Func update(repeating:count:)
 Func UnsafeMutablePointer.moveAssign(from:count:) has been removed
 Func UnsafeMutablePointer.moveUpdate(from:count:) is a new API without @available attribute
 
 // These haven't actually been removed; they were renamed at the source level while
 // retaining their old mangled name. The source break was accepted as part of se-0370.
-Func UnsafeMutableBufferPointer.initialize(from:) has mangled name changing from 'Swift.UnsafeMutableBufferPointer.initialize<A where A == A1.Element, A1: Swift.Sequence>(from: A1) -> (A1.Iterator, Swift.Int)' to 'Swift.UnsafeMutableBufferPointer.initialize<A where A == A1.Element, A1: Swift.Sequence>(from: A1) -> (unwritten: A1.Iterator, index: Swift.Int)'
 Func UnsafeMutableBufferPointer.initialize(from:) has return type change from (τ_1_0.Iterator, Swift.Int) to (unwritten: τ_1_0.Iterator, index: Swift.Int)
 
-// This hasn't actually been removed; it was renamed at the source level while
-// retaining its old mangled/silgen name. The old source-level name is preserved
-// as an @_alwaysEmitIntoClient function. The source break was accepted as part of se-0405.
-Constructor String.init(validatingCString:) is a new API without @available attribute
-Constructor String.init(validatingUTF8:) has been removed
+// This was renamed at the source level while preserving its ABI using @abi.
+// The old source-level name is preserved as an @_alwaysEmitIntoClient function.
+// The source break was accepted as part of se-0405.
+Constructor String.init(validatingUTF8:) has been renamed to Constructor init(validatingCString:)
 
 // These haven't actually been removed; they are simply marked unavailable.
 // This seems to be a false positive in the ABI checker. This is not an ABI
@@ -801,26 +793,17 @@ Func _isPOD(_:) is now with @_preInverseGenerics
 
 Func FixedWidthInteger.&*(_:_:) has been added as a protocol requirement
 
-Func Array.withUnsafeMutableBufferPointer(_:) has been renamed to Func __abi_withUnsafeMutableBufferPointer(_:)
-Func Array.withUnsafeMutableBufferPointer(_:) has mangled name changing from 'Swift.Array.withUnsafeMutableBufferPointer<A>((inout Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1' to 'Swift.Array.__abi_withUnsafeMutableBufferPointer<A>((inout Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1'
-Func ArraySlice.withUnsafeMutableBufferPointer(_:) has been renamed to Func __abi_withUnsafeMutableBufferPointer(_:)
-Func ArraySlice.withUnsafeMutableBufferPointer(_:) has mangled name changing from 'Swift.ArraySlice.withUnsafeMutableBufferPointer<A>((inout Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1' to 'Swift.ArraySlice.__abi_withUnsafeMutableBufferPointer<A>((inout Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1'
-Func ContiguousArray.withUnsafeMutableBufferPointer(_:) has been renamed to Func __abi_withUnsafeMutableBufferPointer(_:)
-Func ContiguousArray.withUnsafeMutableBufferPointer(_:) has mangled name changing from 'Swift.ContiguousArray.withUnsafeMutableBufferPointer<A>((inout Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1' to 'Swift.ContiguousArray.__abi_withUnsafeMutableBufferPointer<A>((inout Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1'
-Func _ArrayBuffer.withUnsafeBufferPointer(_:) has been renamed to Func __abi_withUnsafeBufferPointer(_:)
-Func _ArrayBuffer.withUnsafeBufferPointer(_:) has mangled name changing from 'Swift._ArrayBuffer.withUnsafeBufferPointer<A>((Swift.UnsafeBufferPointer<A>) throws -> A1) throws -> A1' to 'Swift._ArrayBuffer.__abi_withUnsafeBufferPointer<A>((Swift.UnsafeBufferPointer<A>) throws -> A1) throws -> A1'
-Func _ArrayBuffer.withUnsafeMutableBufferPointer(_:) has been renamed to Func __abi_withUnsafeMutableBufferPointer(_:)
-Func _ArrayBuffer.withUnsafeMutableBufferPointer(_:) has mangled name changing from 'Swift._ArrayBuffer.withUnsafeMutableBufferPointer<A>((Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1' to 'Swift._ArrayBuffer.__abi_withUnsafeMutableBufferPointer<A>((Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1'
+Func Array.withUnsafeMutableBufferPointer(_:) has been renamed to Func __rethrows_withUnsafeMutableBufferPointer(_:)
+Func ArraySlice.withUnsafeMutableBufferPointer(_:) has been renamed to Func __rethrows_withUnsafeMutableBufferPointer(_:)
+Func ContiguousArray.withUnsafeMutableBufferPointer(_:) has been renamed to Func __rethrows_withUnsafeMutableBufferPointer(_:)
+Func _ArrayBuffer.withUnsafeBufferPointer(_:) has been renamed to Func __rethrows_withUnsafeBufferPointer(_:)
+Func _ArrayBuffer.withUnsafeMutableBufferPointer(_:) has been renamed to Func __rethrows_withUnsafeMutableBufferPointer(_:)
 Func _ArrayBufferProtocol.withUnsafeBufferPointer(_:) has been added as a protocol requirement
 Func _ArrayBufferProtocol.withUnsafeMutableBufferPointer(_:) has been added as a protocol requirement
-Func _ContiguousArrayBuffer.withUnsafeBufferPointer(_:) has been renamed to Func __abi_withUnsafeBufferPointer(_:)
-Func _ContiguousArrayBuffer.withUnsafeBufferPointer(_:) has mangled name changing from 'Swift._ContiguousArrayBuffer.withUnsafeBufferPointer<A>((Swift.UnsafeBufferPointer<A>) throws -> A1) throws -> A1' to 'Swift._ContiguousArrayBuffer.__abi_withUnsafeBufferPointer<A>((Swift.UnsafeBufferPointer<A>) throws -> A1) throws -> A1'
-Func _ContiguousArrayBuffer.withUnsafeMutableBufferPointer(_:) has been renamed to Func __abi_withUnsafeMutableBufferPointer(_:)
-Func _ContiguousArrayBuffer.withUnsafeMutableBufferPointer(_:) has mangled name changing from 'Swift._ContiguousArrayBuffer.withUnsafeMutableBufferPointer<A>((Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1' to 'Swift._ContiguousArrayBuffer.__abi_withUnsafeMutableBufferPointer<A>((Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1'
-Func _SliceBuffer.withUnsafeBufferPointer(_:) has been renamed to Func __abi_withUnsafeBufferPointer(_:)
-Func _SliceBuffer.withUnsafeBufferPointer(_:) has mangled name changing from 'Swift._SliceBuffer.withUnsafeBufferPointer<A>((Swift.UnsafeBufferPointer<A>) throws -> A1) throws -> A1' to 'Swift._SliceBuffer.__abi_withUnsafeBufferPointer<A>((Swift.UnsafeBufferPointer<A>) throws -> A1) throws -> A1'
-Func _SliceBuffer.withUnsafeMutableBufferPointer(_:) has been renamed to Func __abi_withUnsafeMutableBufferPointer(_:)
-Func _SliceBuffer.withUnsafeMutableBufferPointer(_:) has mangled name changing from 'Swift._SliceBuffer.withUnsafeMutableBufferPointer<A>((Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1' to 'Swift._SliceBuffer.__abi_withUnsafeMutableBufferPointer<A>((Swift.UnsafeMutableBufferPointer<A>) throws -> A1) throws -> A1'
+Func _ContiguousArrayBuffer.withUnsafeBufferPointer(_:) has been renamed to Func __rethrows_withUnsafeBufferPointer(_:)
+Func _ContiguousArrayBuffer.withUnsafeMutableBufferPointer(_:) has been renamed to Func __rethrows_withUnsafeMutableBufferPointer(_:)
+Func _SliceBuffer.withUnsafeBufferPointer(_:) has been renamed to Func __rethrows_withUnsafeBufferPointer(_:)
+Func _SliceBuffer.withUnsafeMutableBufferPointer(_:) has been renamed to Func __rethrows_withUnsafeMutableBufferPointer(_:)
 
 Struct String.Index has added a conformance to an existing protocol CustomDebugStringConvertible