Allow Hashable: ~Copyable

lib/SILGen/SILGenExpr.cpp

@@ -37,6 +37,8 @@
 #include "swift/AST/Expr.h"
 #include "swift/AST/ForeignErrorConvention.h"
 #include "swift/AST/GenericEnvironment.h"
+#include "swift/AST/InFlightSubstitution.h"
+#include "swift/AST/KnownProtocols.h"
 #include "swift/AST/ParameterList.h"
 #include "swift/AST/ProtocolConformance.h"
 #include "swift/AST/SubstitutionMap.h"
@@ -2430,8 +2432,20 @@ RValue SILGenFunction::emitAnyHashableErasure(SILLocation loc,
     return emitUndefRValue(loc, getASTContext().getAnyHashableType());
 
   // Construct the substitution for T: Hashable.
-  auto subMap = SubstitutionMap::getProtocolSubstitutions(
-      conformance.getProtocol(), type, conformance);
+  auto subMap = SubstitutionMap::get(convertFn->getGenericSignature(), type,
+    [&](InFlightSubstitution &ifs,
+        Type ty,
+        ProtocolDecl *proto) -> ProtocolConformanceRef {
+      switch (*proto->getKnownProtocolKind()) {
+      case KnownProtocolKind::Hashable:
+        return conformance;
+      case KnownProtocolKind::Copyable:
+      case KnownProtocolKind::Escapable:
+        return lookupConformance(type, proto);
+      default:
+        llvm_unreachable("no other conformances should be involved");
+      }
+    });
 
   return emitApplyOfLibraryIntrinsic(loc, convertFn, subMap, value, C);
 }

stdlib/public/core/Hashable.swift

@@ -101,7 +101,7 @@
 ///         print("New tap detected at (\(nextTap.x), \(nextTap.y)).")
 ///     }
 ///     // Prints "New tap detected at (0, 1).")
-public protocol Hashable: Equatable {
+public protocol Hashable: Equatable & ~Copyable {
   /// The hash value.
   ///
   /// Hash values are not guaranteed to be equal across different executions of
@@ -135,9 +135,10 @@ public protocol Hashable: Equatable {
   func _rawHashValue(seed: Int) -> Int
 }
 
-extension Hashable {
+extension Hashable where Self: ~Copyable {
   @inlinable
   @inline(__always)
+  @_preInverseGenerics
   public func _rawHashValue(seed: Int) -> Int {
     var hasher = Hasher(_seed: seed)
     hasher.combine(self)
@@ -148,7 +149,8 @@ extension Hashable {
 // Called by synthesized `hashValue` implementations.
 @inlinable
 @inline(__always)
-public func _hashValue<H: Hashable>(for value: H) -> Int {
+@_preInverseGenerics
+public func _hashValue<H: Hashable & ~Copyable>(for value: borrowing H) -> Int {
   return value._rawHashValue(seed: 0)
 }
 

stdlib/public/core/Hasher.swift

@@ -350,7 +350,8 @@ public struct Hasher {
   /// - Parameter value: A value to add to the hasher.
   @inlinable
   @inline(__always)
-  public mutating func combine<H: Hashable>(_ value: H) {
+  @_preInverseGenerics
+  public mutating func combine<H: Hashable & ~Copyable>(_ value: borrowing H) {
     value.hash(into: &self)
   }
 

test/Frontend/dump-parse.swift

@@ -58,7 +58,7 @@ enum TrailingSemi {
 // CHECK-AST-LABEL:   (func_decl{{.*}}"generic(_:)" "<T : Hashable>" interface_type="<T where T : Hashable> (T) -> ()" access=internal captures=(<generic> {{.*}})
 func generic<T: Hashable>(_: T) {}
 // CHECK-AST:       (pattern_binding_decl
-// CHECK-AST:         (processed_init=declref_expr type="(Int) -> ()" location={{.*}} range={{.*}} decl="main.(file).generic@{{.*}} [with (substitution_map generic_signature=<T where T : Hashable> T -> Int)]" function_ref=unapplied))
+// CHECK-AST:         (processed_init=declref_expr type="(Int) -> ()" location={{.*}} range={{.*}} decl="main.(file).generic@{{.*}} [with (substitution_map generic_signature=<T where T : Copyable, T : Hashable> T -> Int)]" function_ref=unapplied))
 let _: (Int) -> () = generic
 
 // Closures should be marked as escaping or not.

test/Parse/inverses.swift

@@ -52,7 +52,9 @@ public struct MoveOnlyS1<T> : ~Copyable { /*deinit {}*/ }
 public struct MoveOnlyS2<T: Equatable> : ~Copyable { /*deinit {}*/ }
 public struct MoveOnlyS3<T: ~Copyable> : ~Copyable { /*deinit {}*/ }
 
-protocol Rope<Element>: Hashable, ~Copyable {  // expected-error {{'Self' required to be 'Copyable' but is marked with '~Copyable'}}
+protocol CopyHashable {  }
+
+protocol Rope<Element>: CopyHashable, ~Copyable {  // expected-error {{'Self' required to be 'Copyable' but is marked with '~Copyable'}}
   associatedtype Element: ~Copyable
 }
 
@@ -102,8 +104,8 @@ typealias Z4 = ~Rope<Int> // expected-error {{type 'Rope<Int>' cannot be suppres
 typealias Z5 = (~Int) -> Void // expected-error {{type 'Int' cannot be suppressed}}
 typealias Z6 = ~() -> () // expected-error {{single argument function types require parentheses}}
                          // expected-error@-1 {{type '()' cannot be suppressed}}
-typealias Z7 = ~(Copyable & Hashable) // expected-error {{type 'Hashable' cannot be suppressed}}
-typealias Z8 = ~Copyable & Hashable // expected-error {{composition cannot contain '~Copyable' when another member requires 'Copyable'}}
+typealias Z7 = ~(Copyable & CopyHashable) // expected-error {{type 'CopyHashable' cannot be suppressed}}
+typealias Z8 = ~Copyable & CopyHashable // expected-error {{composition cannot contain '~Copyable' when another member requires 'Copyable'}}
 
 struct NotAProtocol {}
 

test/SILGen/synthesized_conformance_enum.swift

@@ -83,9 +83,9 @@ extension NoValues: Codable {}
 
 // CHECK-LABEL: sil_witness_table hidden <T where T : Hashable> Enum<T>: Hashable module synthesized_conformance_enum {
 // CHECK-DAG:   base_protocol Equatable: <T where T : Equatable> Enum<T>: Equatable module synthesized_conformance_enum
-// CHECK-DAG:   method #Hashable.hashValue!getter: <Self where Self : Hashable> (Self) -> () -> Int : @$s28synthesized_conformance_enum4EnumOyxGSHAASHRzlSH9hashValueSivgTW	// protocol witness for Hashable.hashValue.getter in conformance <A> Enum<A>
-// CHECK-DAG:   method #Hashable.hash: <Self where Self : Hashable> (Self) -> (inout Hasher) -> () : @$s28synthesized_conformance_enum4EnumOyxGSHAASHRzlSH4hash4intoys6HasherVz_tFTW	// protocol witness for Hashable.hash(into:) in conformance <A> Enum<A>
-// CHECK-DAG:   method #Hashable._rawHashValue: <Self where Self : Hashable> (Self) -> (Int) -> Int : @$s28synthesized_conformance_enum4EnumOyxGSHAASHRzlSH13_rawHashValue4seedS2i_tFTW // protocol witness for Hashable._rawHashValue(seed:) in conformance <A> Enum<A>
+// CHECK-DAG:   method #Hashable.hashValue!getter: <Self where Self : Hashable, Self : ~Copyable> (Self) -> () -> Int : @$s28synthesized_conformance_enum4EnumOyxGSHAASHRzlSH9hashValueSivgTW	// protocol witness for Hashable.hashValue.getter in conformance <A> Enum<A>
+// CHECK-DAG:   method #Hashable.hash: <Self where Self : Hashable, Self : ~Copyable> (Self) -> (inout Hasher) -> () : @$s28synthesized_conformance_enum4EnumOyxGSHAASHRzlSH4hash4intoys6HasherVz_tFTW	// protocol witness for Hashable.hash(into:) in conformance <A> Enum<A>
+// CHECK-DAG:   method #Hashable._rawHashValue: <Self where Self : Hashable, Self : ~Copyable> (Self) -> (Int) -> Int : @$s28synthesized_conformance_enum4EnumOyxGSHAASHRzlSH13_rawHashValue4seedS2i_tFTW // protocol witness for Hashable._rawHashValue(seed:) in conformance <A> Enum<A>
 // CHECK-DAG:   conditional_conformance (T: Hashable): dependent
 // CHECK: }
 

test/SILGen/synthesized_conformance_struct.swift

@@ -69,9 +69,9 @@ extension Struct: Codable where T: Codable {}
 
 // CHECK-LABEL: sil_witness_table hidden <T where T : Hashable> Struct<T>: Hashable module synthesized_conformance_struct {
 // CHECK-DAG:   base_protocol Equatable: <T where T : Equatable> Struct<T>: Equatable module synthesized_conformance_struct
-// CHECK-DAG:   method #Hashable.hashValue!getter: <Self where Self : Hashable> (Self) -> () -> Int : @$s30synthesized_conformance_struct6StructVyxGSHAASHRzlSH9hashValueSivgTW	// protocol witness for Hashable.hashValue.getter in conformance <A> Struct<A>
-// CHECK-DAG:   method #Hashable.hash: <Self where Self : Hashable> (Self) -> (inout Hasher) -> () : @$s30synthesized_conformance_struct6StructVyxGSHAASHRzlSH4hash4intoys6HasherVz_tFTW	// protocol witness for Hashable.hash(into:) in conformance <A> Struct<A>
-// CHECK-DAG:   method #Hashable._rawHashValue: <Self where Self : Hashable> (Self) -> (Int) -> Int : @$s30synthesized_conformance_struct6StructVyxGSHAASHRzlSH13_rawHashValue4seedS2i_tFTW // protocol witness for Hashable._rawHashValue(seed:) in conformance <A> Struct<A>
+// CHECK-DAG:   method #Hashable.hashValue!getter: <Self where Self : Hashable, Self : ~Copyable> (Self) -> () -> Int : @$s30synthesized_conformance_struct6StructVyxGSHAASHRzlSH9hashValueSivgTW	// protocol witness for Hashable.hashValue.getter in conformance <A> Struct<A>
+// CHECK-DAG:   method #Hashable.hash: <Self where Self : Hashable, Self : ~Copyable> (Self) -> (inout Hasher) -> () : @$s30synthesized_conformance_struct6StructVyxGSHAASHRzlSH4hash4intoys6HasherVz_tFTW	// protocol witness for Hashable.hash(into:) in conformance <A> Struct<A>
+// CHECK-DAG:   method #Hashable._rawHashValue: <Self where Self : Hashable, Self : ~Copyable> (Self) -> (Int) -> Int : @$s30synthesized_conformance_struct6StructVyxGSHAASHRzlSH13_rawHashValue4seedS2i_tFTW // protocol witness for Hashable._rawHashValue(seed:) in conformance <A> Struct<A>
 // CHECK-DAG:   conditional_conformance (T: Hashable): dependent
 // CHECK: }
 

test/Sema/moveonly_illegal_types.swift

@@ -52,11 +52,11 @@ func basic_vararg(_ va: MO...) {} // expected-error {{noncopyable type 'MO' cann
 func illegalTypes<T>(_ t: T) {
   let _: Array<MO> // expected-error {{type 'MO' does not conform to protocol 'Copyable'}}
   let _: Maybe<MO> // expected-error {{type 'MO' does not conform to protocol 'Copyable'}}
-  let _: Dictionary<MO, String> // expected-error {{type 'MO' does not conform to protocol 'Hashable'}}
+  let _: Dictionary<MO, String> // expected-error {{type 'MO' does not conform to protocol 'Copyable'}}
   let _: [MO] // expected-error {{type 'MO' does not conform to protocol 'Copyable'}}
   let _: [String : MO] // expected-error {{type 'MO' does not conform to protocol 'Copyable'}}
-  let _: [MO : MO] // expected-error {{type 'MO' does not conform to protocol 'Hashable'}}
-  let _: [MO : T] // expected-error {{type 'MO' does not conform to protocol 'Hashable'}}
+  let _: [MO : MO] // expected-error {{type 'MO' does not conform to protocol 'Copyable'}}
+  let _: [MO : T] // expected-error {{type 'MO' does not conform to protocol 'Copyable'}}
 
   _ = t as! ValBox<MO> // expected-error {{type 'MO' does not conform to protocol 'Copyable'}}
 

test/api-digester/Outputs/stability-stdlib-source-base.swift.expected

@@ -114,7 +114,6 @@ Protocol FixedWidthInteger has added inherited protocol Copyable
 Protocol FixedWidthInteger has added inherited protocol Escapable
 Protocol FloatingPoint has added inherited protocol Copyable
 Protocol FloatingPoint has added inherited protocol Escapable
-Protocol Hashable has added inherited protocol Copyable
 Protocol Hashable has added inherited protocol Escapable
 Protocol Identifiable has added inherited protocol Copyable
 Protocol Identifiable has added inherited protocol Escapable
@@ -399,3 +398,10 @@ Func Comparable.>(_:_:) has parameter 1 changing from Default to Shared
 Func Comparable.>=(_:_:) has generic signature change from <Self where Self : Swift.Comparable> to <Self where Self : Swift.Comparable, Self : ~Copyable>
 Func Comparable.>=(_:_:) has parameter 0 changing from Default to Shared
 Func Comparable.>=(_:_:) has parameter 1 changing from Default to Shared
+
+// Hashable: ~Copyable
+Protocol Hashable has generic signature change from <Self : Swift.Equatable> to <Self : Swift.Equatable, Self : ~Copyable>
+Accessor Hashable.hashValue.Get() has generic signature change from <Self where Self : Swift.Hashable> to <Self where Self : Swift.Hashable, Self : ~Copyable>
+Func Hashable.hash(into:) has generic signature change from <Self where Self : Swift.Hashable> to <Self where Self : Swift.Hashable, Self : ~Copyable>
+Func Hasher.combine(_:) has generic signature change from <H where H : Swift.Hashable> to <H where H : Swift.Hashable, H : ~Copyable>
+Func Hasher.combine(_:) has parameter 0 changing from Default to Shared

test/api-digester/stability-stdlib-abi-without-asserts.test

@@ -232,7 +232,6 @@ Protocol FixedWidthInteger has added inherited protocol Copyable
 Protocol FixedWidthInteger has added inherited protocol Escapable
 Protocol FloatingPoint has added inherited protocol Copyable
 Protocol FloatingPoint has added inherited protocol Escapable
-Protocol Hashable has added inherited protocol Copyable
 Protocol Hashable has added inherited protocol Escapable
 Protocol Identifiable has added inherited protocol Copyable
 Protocol Identifiable has added inherited protocol Escapable
@@ -911,5 +910,20 @@ Func Comparable.>=(_:_:) has parameter 0 changing from Default to Shared
 Func Comparable.>=(_:_:) has parameter 1 changing from Default to Shared
 Func Comparable.>=(_:_:) is now with @_preInverseGenerics
 
+// Hashable: ~Copyable
+Protocol Hashable has generic signature change from <Self : Swift.Equatable> to <Self : Swift.Equatable, Self : ~Copyable>
+Accessor Hashable.hashValue.Get() has generic signature change from <Self where Self : Swift.Hashable> to <Self where Self : Swift.Hashable, Self : ~Copyable>
+Func Hashable._rawHashValue(seed:) has generic signature change from <Self where Self : Swift.Hashable> to <Self where Self : Swift.Hashable, Self : ~Copyable>
+Func Hashable._rawHashValue(seed:) has mangled name changing from '(extension in Swift):Swift.Hashable._rawHashValue(seed: Swift.Int) -> Swift.Int' to '(extension in Swift):Swift.Hashable< where A: ~Swift.Copyable>._rawHashValue(seed: Swift.Int) -> Swift.Int'
+Func Hashable._rawHashValue(seed:) is now with @_preInverseGenerics
+Func Hashable.hash(into:) has generic signature change from <Self where Self : Swift.Hashable> to <Self where Self : Swift.Hashable, Self : ~Copyable>
+Func Hasher.combine(_:) has generic signature change from <H where H : Swift.Hashable> to <H where H : Swift.Hashable, H : ~Copyable>
+Func Hasher.combine(_:) has mangled name changing from 'Swift.Hasher.combine<A where A: Swift.Hashable>(A) -> ()' to 'Swift.Hasher.combine<A where A: Swift.Hashable, A: ~Swift.Copyable>(A) -> ()'
+Func Hasher.combine(_:) has parameter 0 changing from Default to Shared
+Func Hasher.combine(_:) is now with @_preInverseGenerics
+Func _hashValue(for:) has generic signature change from <H where H : Swift.Hashable> to <H where H : Swift.Hashable, H : ~Copyable>
+Func _hashValue(for:) has mangled name changing from 'Swift._hashValue<A where A: Swift.Hashable>(for: A) -> Swift.Int' to 'Swift._hashValue<A where A: Swift.Hashable, A: ~Swift.Copyable>(for: A) -> Swift.Int'
+Func _hashValue(for:) has parameter 0 changing from Default to Shared
+Func _hashValue(for:) is now with @_preInverseGenerics
 
 // *** DO NOT DISABLE OR XFAIL THIS TEST. *** (See comment above.)

test/stdlib/NoncopyableHashable.swift

@@ -0,0 +1,75 @@
+//===--- NoncopyableHashable.swift - tests for Hashable: ~Copyable ----------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+// RUN: %target-run-simple-swift
+// REQUIRES: executable_test
+
+import StdlibUnittest
+
+let NoncopyableHashableTests = TestSuite("NoncopyableHashable")
+
+struct Noncopyable<Wrapped: ~Copyable>: ~Copyable {
+  var wrapped: Wrapped
+}
+
+extension Noncopyable: Equatable where Wrapped: Equatable & ~Copyable { }
+
+extension Noncopyable: Hashable where Wrapped: Hashable & ~Copyable { }
+
+
+extension Hashable where Self: ~Copyable {
+  func sameHash(as other: borrowing Self) -> Bool {
+    self.hashValue == other.hashValue
+  }
+}
+
+func differentHash<T: Hashable & ~Copyable>(_ lhs: borrowing T, _ rhs: borrowing T) -> Bool {
+  lhs.hashValue != rhs.hashValue
+}
+
+@available(SwiftStdlib 6.2, *)
+extension InlineArray where Element: Hashable & ~Copyable {
+  func combinedHashes() -> Int {
+    var hasher = Hasher()
+    for i in self.indices {
+      self[i].hash(into: &hasher)
+    }
+    return hasher.finalize()
+  }
+}
+
+NoncopyableHashableTests.test("hashing noncopyables") {
+  let a = Noncopyable(wrapped: 1)
+  let b = Noncopyable(wrapped: 2)
+  let c = Noncopyable(wrapped: 1)
+
+  expectTrue(a.sameHash(as: a))
+  expectFalse(a.sameHash(as: b))
+  expectTrue(a.sameHash(as: c))
+
+  expectTrue(differentHash(a,b))
+  expectFalse(differentHash(a,a))
+  expectFalse(differentHash(a,c))
+
+  let nc2 = Noncopyable(wrapped: Noncopyable(wrapped: "1"))
+  expectTrue(nc2.sameHash(as: nc2))
+  expectTrue(differentHash(nc2, .init(wrapped: .init(wrapped: "2"))))
+
+  guard #available(SwiftStdlib 6.2, *) else { return }
+
+  let a1: [_ of _] = [a,b]
+  let d = Noncopyable(wrapped: 2)
+  let a2: [_ of _] = [c,d]
+  expectEqual(a1.combinedHashes(), a2.combinedHashes())
+
+}
+
+runAllTests()