Add serialization/deserialization support to lifetime depedence on initializers

Author: meg-gupta

include/swift/AST/Decl.h

@@ -8334,6 +8334,8 @@ class ConstructorDecl : public AbstractFunctionDecl {
 
   TypeRepr *getResultTypeRepr() const { return InitRetType.getTypeRepr(); }
 
+  void setDeserializedResultTypeLoc(TypeLoc ResultTyR);
+
   /// Get the typechecked call to super.init expression, which needs to be
   /// inserted at the end of the initializer by SILGen.
   Expr *getSuperInitCall() { return CallToSuperInit; }

lib/AST/Decl.cpp

@@ -10423,6 +10423,10 @@ ConstructorDecl *ConstructorDecl::createImported(
   return ctor;
 }
 
+void ConstructorDecl::setDeserializedResultTypeLoc(TypeLoc ResultTyR) {
+  InitRetType = ResultTyR;
+}
+
 bool ConstructorDecl::isObjCZeroParameterWithLongSelector() const {
   // The initializer must have a single, non-empty argument name.
   if (getName().getArgumentNames().size() != 1 ||

lib/Serialization/Deserialization.cpp

@@ -3532,7 +3532,6 @@ class DeclDeserializer {
       return thrownTypeOrError.takeError();
     const auto thrownType = thrownTypeOrError.get();
 
-    // Handle LifetimeDependence here
     auto ctor = MF.createDecl<ConstructorDecl>(name, SourceLoc(), isFailable,
                                                /*FailabilityLoc=*/SourceLoc(),
                                                /*Async=*/async,
@@ -3556,6 +3555,15 @@ class DeclDeserializer {
     assert(bodyParams && "missing parameters for constructor");
     ctor->setParameters(bodyParams);
 
+    SmallVector<LifetimeDependenceSpecifier> specifierList;
+    if (MF.maybeReadLifetimeDependence(specifierList, bodyParams->size())) {
+      auto SelfType = ctor->getDeclaredInterfaceType();
+      auto typeRepr = new (ctx) FixedTypeRepr(SelfType, SourceLoc());
+      auto lifetimeTypeRepr =
+          LifetimeDependentReturnTypeRepr::create(ctx, typeRepr, specifierList);
+      ctor->setDeserializedResultTypeLoc(TypeLoc(lifetimeTypeRepr, SelfType));
+    }
+
     if (auto errorConvention = MF.maybeReadForeignErrorConvention())
       ctor->setForeignErrorConvention(*errorConvention);
     if (auto asyncConvention = MF.maybeReadForeignAsyncConvention())

lib/Serialization/Serialization.cpp

@@ -4783,6 +4783,12 @@ class Serializer::DeclSerializer : public DeclVisitor<DeclSerializer> {
     writeGenericParams(ctor->getGenericParams());
     writeParameterList(ctor->getParameters());
 
+    auto fnType = ty->getAs<FunctionType>();
+    if (fnType && fnType->hasLifetimeDependenceInfo()) {
+      assert(!fnType->getLifetimeDependenceInfo().empty());
+      writeLifetimeDependenceInfo(fnType->getLifetimeDependenceInfo());
+    }
+
     if (auto errorConvention = ctor->getForeignErrorConvention())
       writeForeignErrorConvention(*errorConvention);
     if (auto asyncConvention = ctor->getForeignAsyncConvention())

test/Serialization/Inputs/def_explicit_lifetime_dependence.swift

@@ -4,6 +4,18 @@ public struct BufferView : ~Escapable {
   public init(_ ptr: UnsafeRawBufferPointer) {
     self.ptr = ptr
   }
+  public init(_ ptr: UnsafeRawBufferPointer, _ a: borrowing Array<Int>) -> _borrow(a) Self {
+    self.ptr = ptr
+    return self
+  }
+  public init(_ ptr: UnsafeRawBufferPointer, _ a: consuming Array<Double>) -> _consume(a) Self {
+    self.ptr = ptr
+    return self
+  }
+  public init(_ ptr: UnsafeRawBufferPointer, _ a: consuming Array<Int>, _ b: borrowing Array<Int>) -> _consume(a) _borrow(b) Self {
+    self.ptr = ptr
+    return self
+  }
 }
 
 public struct MutableBufferView : ~Escapable, ~Copyable {

test/Serialization/Inputs/def_implicit_lifetime_dependence.swift

@@ -4,6 +4,9 @@ public struct BufferView : ~Escapable {
   public init(_ ptr: UnsafeRawBufferPointer) {
     self.ptr = ptr
   }
+  public init(_ otherBV: borrowing BufferView) {
+    self.ptr = otherBV.ptr
+  }
 }
 
 public struct MutableBufferView : ~Escapable, ~Copyable {

test/Serialization/explicit_lifetime_dependence.swift

@@ -28,7 +28,22 @@ func testBasic() {
   }
 }
 
+func testInitializers() {
+  let capacity = 4
+  let a = Array(0..<capacity)
+  let b = Array(0..<capacity)
+  a.withUnsafeBytes {
+    let view1 = BufferView($0, a)
+    let view2 = BufferView($0, a, b)
+    let mysteryView = deriveThisOrThat(view1, view2)
+    use(mysteryView)
+  }
+}
 // CHECK: sil @$s32def_explicit_lifetime_dependence6deriveyAA10BufferViewVADF : $@convention(thin) (@guaranteed BufferView) -> _borrow(1) @owned BufferView
 // CHECK: sil @$s32def_explicit_lifetime_dependence16consumeAndCreateyAA10BufferViewVADnF : $@convention(thin) (@owned BufferView) -> _inherit(1) @owned BufferView
 // CHECK: sil @$s32def_explicit_lifetime_dependence15borrowAndCreateyAA10BufferViewVADF : $@convention(thin) (@guaranteed BufferView) -> _borrow(1) @owned BufferView
 // CHECK: sil @$s32def_explicit_lifetime_dependence16deriveThisOrThatyAA10BufferViewVAD_ADtF : $@convention(thin) (@guaranteed BufferView, @guaranteed BufferView) -> _borrow(1, 2) @owned BufferView
+
+// CHECK: sil @$s32def_explicit_lifetime_dependence10BufferViewVyACSW_SaySiGhtcfC : $@convention(method) (UnsafeRawBufferPointer, @guaranteed Array<Int>, @thin BufferView.Type) -> _borrow(2) @owned BufferView
+
+// CHECK: sil @$s32def_explicit_lifetime_dependence10BufferViewVyACSW_SaySiGADhtcfC : $@convention(method) (UnsafeRawBufferPointer, @owned Array<Int>, @guaranteed Array<Int>, @thin BufferView.Type) -> _inherit(2)_borrow(3) @owned BufferView

test/Serialization/implicit_lifetime_dependence.swift

@@ -28,7 +28,26 @@ func testBasic() {
   }
 }
 
+func testInitializers() {
+  let capacity = 4
+  let a = Array(0..<capacity)
+  a.withUnsafeBytes {
+    let view1 = BufferView($0)
+    let view2 = BufferView(view1)
+    let view3 = BufferView(view2)
+    use(view3)
+  }
+}
+
+func unsafetest(_ ptr: UnsafeRawBufferPointer) {
+  let view1 = BufferView(ptr)
+  let view2 = BufferView(view1)
+  let view3 = BufferView(view2)
+  use(view3)
+}
+
 // CHECK: sil @$s32def_implicit_lifetime_dependence6deriveyAA10BufferViewVADF : $@convention(thin) (@guaranteed BufferView) -> _borrow(1) @owned BufferView
 // CHECK: sil @$s32def_implicit_lifetime_dependence16consumeAndCreateyAA10BufferViewVADnF : $@convention(thin) (@owned BufferView) -> _inherit(1) @owned BufferView
 // CHECK: sil @$s32def_implicit_lifetime_dependence15borrowAndCreateyAA10BufferViewVADF : $@convention(thin) (@guaranteed BufferView) -> _borrow(1) @owned BufferView
+// CHECK: sil @$s32def_implicit_lifetime_dependence10BufferViewVyA2ChcfC : $@convention(method) (@guaranteed BufferView, @thin BufferView.Type) -> _borrow(1) @owned BufferView