SIL: Use @in_guaranteed convention for 'self' parameter of materializeForSet callback of non-mutating setter

We cannot in general use @guaranteed here, otherwise classes will not
be able to conform to protocols with mutable property requirements
(or we could always open-code materializeForSet witness thunks for
classes, but that has its own downsides so its not a clear win).

Fixes <rdar://problem/36867783>.

Author: slavapestov

lib/SIL/TypeLowering.cpp

@@ -2071,25 +2071,28 @@ CanSILFunctionType TypeConverter::getMaterializeForSetCallbackType(
   auto selfMetatypeType = MetatypeType::get(selfType,
                                             MetatypeRepresentation::Thick);
 
+  auto canSelfType = selfType->getCanonicalType(genericSig);
+  auto canSelfMetatypeType = selfMetatypeType->getCanonicalType(genericSig);
+  auto selfConvention = (storage->isSetterMutating()
+                         ? ParameterConvention::Indirect_Inout
+                         : ParameterConvention::Indirect_In_Guaranteed);
+
   {
     GenericContextScope scope(*this, genericSig);
 
     // If 'self' is a metatype, make it @thin or @thick as needed, but not inside
     // selfMetatypeType.
-    if (auto metatype = selfType->getAs<MetatypeType>()) {
+    if (auto metatype = canSelfType->getAs<MetatypeType>()) {
       if (!metatype->hasRepresentation())
-        selfType = getLoweredType(metatype).getSwiftRValueType();
+        canSelfType = getLoweredType(metatype).getSwiftRValueType();
     }
   }
 
-  auto canSelfType = selfType->getCanonicalType(genericSig);
-  auto canSelfMetatypeType = selfMetatypeType->getCanonicalType(genericSig);
-
   // Create the SILFunctionType for the callback.
   SILParameterInfo params[] = {
     { ctx.TheRawPointerType, ParameterConvention::Direct_Unowned },
     { ctx.TheUnsafeValueBufferType, ParameterConvention::Indirect_Inout },
-    { canSelfType, ParameterConvention::Indirect_Inout },
+    { canSelfType, selfConvention },
     { canSelfMetatypeType, ParameterConvention::Direct_Unowned },
   };
   ArrayRef<SILResultInfo> results = {};

lib/SILGen/SILGenMaterializeForSet.cpp

@@ -964,7 +964,7 @@ MaterializeForSetEmitter::createSetterCallback(SILFunction &F,
     }
 
     // The callback gets the address of 'self' at +0.
-    ManagedValue mSelf = ManagedValue::forLValue(self);
+    ManagedValue mSelf = ManagedValue::forUnmanaged(self);
 
     // That's enough to build the l-value.
     LValue lvalue = buildLValue(SGF, loc, mSelf, std::move(indices),

test/SILGen/accessors.swift

@@ -65,9 +65,8 @@ func test0(_ ref: A) {
 // CHECK-NEXT: switch_enum [[OPT_CALLBACK]] : $Optional<Builtin.RawPointer>, case #Optional.some!enumelt.1: [[WRITEBACK:bb[0-9]+]], case #Optional.none!enumelt: [[CONT:bb[0-9]+]]
 
 // CHECK:    [[WRITEBACK]]([[CALLBACK_ADDR:%.*]] : @trivial $Builtin.RawPointer):
-// CHECK-NEXT: [[CALLBACK:%.*]] = pointer_to_thin_function [[CALLBACK_ADDR]] : $Builtin.RawPointer to $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout A, @thick A.Type) -> ()
+// CHECK-NEXT: [[CALLBACK:%.*]] = pointer_to_thin_function [[CALLBACK_ADDR]] : $Builtin.RawPointer to $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed A, @thick A.Type) -> ()
 // CHECK-NEXT: [[TEMP2:%.*]] = alloc_stack $A
-// SEMANTIC SIL TODO: This is an issue caused by the callback for materializeForSet in the class case taking the value as @inout when it should really take it as @guaranteed.
 // CHECK-NEXT: store_borrow [[BORROWED_ARG_LHS]] to [[TEMP2]] : $*A
 // CHECK-NEXT: [[T0:%.*]] = metatype $@thick A.Type
 // CHECK-NEXT: [[T1:%.*]] = address_to_pointer [[ADDR]] : $*OrdinarySub to $Builtin.RawPointer
@@ -128,7 +127,7 @@ func test1(_ ref: B) {
 // CHECK-NEXT: switch_enum [[OPT_CALLBACK]] : $Optional<Builtin.RawPointer>, case #Optional.some!enumelt.1: [[WRITEBACK:bb[0-9]+]], case #Optional.none!enumelt: [[CONT:bb[0-9]+]]
 //
 // CHECK:    [[WRITEBACK]]([[CALLBACK_ADDR:%.*]] : @trivial $Builtin.RawPointer):
-// CHECK-NEXT: [[CALLBACK:%.*]] = pointer_to_thin_function [[CALLBACK_ADDR]] : $Builtin.RawPointer to $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout B, @thick B.Type) -> ()
+// CHECK-NEXT: [[CALLBACK:%.*]] = pointer_to_thin_function [[CALLBACK_ADDR]] : $Builtin.RawPointer to $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed B, @thick B.Type) -> ()
 // CHECK-NEXT: [[TEMP2:%.*]] = alloc_stack $B
 // CHECK-NEXT: store_borrow [[BORROWED_ARG_RHS]] to [[TEMP2]] : $*B
 // CHECK-NEXT: [[T0:%.*]] = metatype $@thick B.Type
@@ -154,7 +153,7 @@ func test1(_ ref: B) {
 // CHECK-NEXT: switch_enum [[OPT_CALLBACK]] : $Optional<Builtin.RawPointer>, case #Optional.some!enumelt.1: [[WRITEBACK:bb[0-9]+]], case #Optional.none!enumelt: [[CONT:bb[0-9]+]]
 //
 // CHECK:    [[WRITEBACK]]([[CALLBACK_ADDR:%.*]] : @trivial $Builtin.RawPointer):
-// CHECK-NEXT: [[CALLBACK:%.*]] = pointer_to_thin_function [[CALLBACK_ADDR]] : $Builtin.RawPointer to $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout B, @thick B.Type) -> ()
+// CHECK-NEXT: [[CALLBACK:%.*]] = pointer_to_thin_function [[CALLBACK_ADDR]] : $Builtin.RawPointer to $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed B, @thick B.Type) -> ()
 // CHECK-NEXT: [[TEMP2:%.*]] = alloc_stack $B
 // CHECK-NEXT: store_borrow [[BORROWED_ARG_LHS]] to [[TEMP2]] : $*B
 // CHECK-NEXT: [[T0:%.*]] = metatype $@thick B.Type

test/SILGen/addressors.swift

@@ -354,7 +354,7 @@ class G {
 // CHECK:   strong_release [[OWNER]] : $Builtin.NativeObject
 
 //   materializeForSet callback for G.value
-// CHECK-LABEL: sil private [transparent] @$S10addressors1GC5values5Int32VvmytfU_ : $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout G, @thick G.Type) -> () {
+// CHECK-LABEL: sil private [transparent] @$S10addressors1GC5values5Int32VvmytfU_ : $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed G, @thick G.Type) -> () {
 // CHECK: bb0([[BUFFER:%0]] : $Builtin.RawPointer, [[STORAGE:%1]] : $*Builtin.UnsafeValueBuffer, [[SELF:%2]] : $*G, [[SELFTYPE:%3]] : $@thick G.Type):
 // CHECK:   [[T0:%.*]] = project_value_buffer $Builtin.NativeObject in [[STORAGE]] : $*Builtin.UnsafeValueBuffer
 // CHECK:   [[OWNER:%.*]] = load [[T0]]
@@ -475,7 +475,7 @@ class I {
 // CHECK:   strong_unpin [[OWNER]] : $Optional<Builtin.NativeObject>
 
 //   materializeForSet callback for I.value
-// CHECK-LABEL: sil private [transparent] @$S10addressors1IC5values5Int32VvmytfU_ : $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout I, @thick I.Type) -> () {
+// CHECK-LABEL: sil private [transparent] @$S10addressors1IC5values5Int32VvmytfU_ : $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed I, @thick I.Type) -> () {
 // CHECK: bb0([[BUFFER:%0]] : $Builtin.RawPointer, [[STORAGE:%1]] : $*Builtin.UnsafeValueBuffer, [[SELF:%2]] : $*I, [[SELFTYPE:%3]] : $@thick I.Type):
 // CHECK:   [[T0:%.*]] = project_value_buffer $Optional<Builtin.NativeObject> in [[STORAGE]] : $*Builtin.UnsafeValueBuffer
 // CHECK:   [[OWNER:%.*]] = load [[T0]]

test/SILGen/constrained_extensions.swift

@@ -137,7 +137,7 @@ public class GenericClass<X, Y> {}
 extension GenericClass where Y == () {
   // CHECK-LABEL: sil @$S22constrained_extensions12GenericClassCAAytRs_rlE5valuexvg : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @out X
   // CHECK-LABEL: sil @$S22constrained_extensions12GenericClassCAAytRs_rlE5valuexvs : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
-  // CHECK-LABEL: sil shared [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlE5valuexvmytfU_ : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout GenericClass<X, ()>, @thick GenericClass<X, ()>.Type) -> ()
+  // CHECK-LABEL: sil shared [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlE5valuexvmytfU_ : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed GenericClass<X, ()>, @thick GenericClass<X, ()>.Type) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlE5valuexvm : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @guaranteed GenericClass<X, ()>) -> (Builtin.RawPointer, Optional<Builtin.RawPointer>)
   public var value: X {
     get { while true {} }
@@ -146,7 +146,7 @@ extension GenericClass where Y == () {
 
   // CHECK-LABEL: sil @$S22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvg : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> ()
   // CHECK-LABEL: sil @$S22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvs : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> ()
-  // CHECK-LABEL: sil shared [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvmytfU_ : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout GenericClass<X, ()>, @thick GenericClass<X, ()>.Type) -> ()
+  // CHECK-LABEL: sil shared [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvmytfU_ : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed GenericClass<X, ()>, @thick GenericClass<X, ()>.Type) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlE5emptyytvm : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @guaranteed GenericClass<X, ()>) -> (Builtin.RawPointer, Optional<Builtin.RawPointer>)
   public var empty: Y {
     get { return () }
@@ -155,7 +155,7 @@ extension GenericClass where Y == () {
 
   // CHECK-LABEL: sil @$S22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tcig : $@convention(method) <X, Y where Y == ()> (@guaranteed GenericClass<X, ()>) -> @out X
   // CHECK-LABEL: sil @$S22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tcis : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
-  // CHECK-LABEL: sil shared [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tcimytfU_ : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout GenericClass<X, ()>, @thick GenericClass<X, ()>.Type) -> ()
+  // CHECK-LABEL: sil shared [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tcimytfU_ : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed GenericClass<X, ()>, @thick GenericClass<X, ()>.Type) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlEyxyt_tcim : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @guaranteed GenericClass<X, ()>) -> (Builtin.RawPointer, Optional<Builtin.RawPointer>)
   public subscript(_: Y) -> X {
     get { while true {} }
@@ -164,7 +164,7 @@ extension GenericClass where Y == () {
 
   // CHECK-LABEL: sil @$S22constrained_extensions12GenericClassCAAytRs_rlEyyxcig : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
   // CHECK-LABEL: sil @$S22constrained_extensions12GenericClassCAAytRs_rlEyyxcis : $@convention(method) <X, Y where Y == ()> (@in X, @guaranteed GenericClass<X, ()>) -> ()
-  // CHECK-LABEL: sil shared [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlEyyxcimytfU_ : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout GenericClass<X, ()>, @thick GenericClass<X, ()>.Type) -> ()
+  // CHECK-LABEL: sil shared [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlEyyxcimytfU_ : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed GenericClass<X, ()>, @thick GenericClass<X, ()>.Type) -> ()
   // CHECK-LABEL: sil [transparent] [serialized] @$S22constrained_extensions12GenericClassCAAytRs_rlEyyxcim : $@convention(method) <X, Y where Y == ()> (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in X, @guaranteed GenericClass<X, ()>) -> (Builtin.RawPointer, Optional<Builtin.RawPointer>)
   public subscript(_: X) -> Y {
     get { while true {} }

test/SILGen/lifetime.swift

@@ -389,7 +389,7 @@ func logical_lvalue_lifetime(_ r: RefWithProp, _ i: Int, _ v: Val) {
   // CHECK: [[ADDR:%.*]] = pointer_to_address [[PTR]]
   // CHECK: [[MARKED_ADDR:%.*]] = mark_dependence [[ADDR]] : $*Aleph on [[R2]]
   // CHECK: {{.*}}([[CALLBACK_ADDR:%.*]] : 
-  // CHECK: [[CALLBACK:%.*]] = pointer_to_thin_function [[CALLBACK_ADDR]] : $Builtin.RawPointer to $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @inout RefWithProp, @thick RefWithProp.Type) -> ()
+  // CHECK: [[CALLBACK:%.*]] = pointer_to_thin_function [[CALLBACK_ADDR]] : $Builtin.RawPointer to $@convention(method) (Builtin.RawPointer, @inout Builtin.UnsafeValueBuffer, @in_guaranteed RefWithProp, @thick RefWithProp.Type) -> ()
   // CHECK: [[TEMP:%.*]] = alloc_stack $RefWithProp
   // CHECK: store [[R2]] to [init] [[TEMP]]
   // CHECK: apply [[CALLBACK]]({{.*}}, [[STORAGE]], [[TEMP]], {{%.*}})