Merge pull request #71665 from meg-gupta/fixgeninit

Fix generic initializers with lifetime dependence

Author: meg-gupta

include/swift/AST/AnyFunctionRef.h

@@ -118,7 +118,7 @@ class AnyFunctionRef {
         return FD->mapTypeIntoContext(FD->getResultInterfaceType());
       if (auto *CD = dyn_cast<ConstructorDecl>(AFD)) {
         if (CD->hasLifetimeDependentReturn()) {
-          return CD->getResultInterfaceType();
+          return CD->mapTypeIntoContext(CD->getResultInterfaceType());
         }
       }
       return TupleType::getEmpty(AFD->getASTContext());

lib/AST/ASTVerifier.cpp

@@ -1078,6 +1078,7 @@ class Verifier : public ASTWalker {
       } else if (auto *CD = dyn_cast<ConstructorDecl>(func)) {
         if (CD->hasLifetimeDependentReturn()) {
           resultType = CD->getResultInterfaceType();
+          resultType = CD->mapTypeIntoContext(resultType);
         } else {
           resultType = TupleType::getEmpty(Ctx);
         }

lib/Sema/TypeCheckStmt.cpp

@@ -1719,16 +1719,10 @@ Stmt *PreCheckReturnStmtRequest::evaluate(Evaluator &evaluator, ReturnStmt *RS,
     auto *nilExpr = dyn_cast<NilLiteralExpr>(E->getSemanticsProvidingExpr());
     if (!nilExpr) {
       if (ctor->hasLifetimeDependentReturn()) {
-        // Typecheck the expression unconditionally.
-        TypeChecker::typeCheckExpression(E, DC, {});
-
-        auto *checkE = E;
-        if (auto *load = dyn_cast<LoadExpr>(checkE))
-          checkE = load->getSubExpr();
         bool isSelf = false;
-        if (auto DRE = dyn_cast<DeclRefExpr>(checkE))
-          isSelf = DRE->getDecl() == ctor->getImplicitSelfDecl();
-
+        if (auto *UDRE = dyn_cast<UnresolvedDeclRefExpr>(E)) {
+          isSelf = UDRE->getName().isSimpleName(ctx.Id_self);
+        }
         if (!isSelf) {
           ctx.Diags.diagnose(
               RS->getStartLoc(),

test/Sema/explicit_lifetime_dependence_specifiers.swift

@@ -137,3 +137,27 @@ struct Wrapper : ~Escapable {
     return view
   } 
 }
+
+public struct GenericBufferView<Element> : ~Escapable {
+  public typealias Index = Int
+  public typealias Pointer = UnsafePointer<Element>
+
+  public let baseAddress: Pointer
+  public let count: Int
+
+  public init<Storage>(unsafeBuffer: UnsafeBufferPointer<Element>,
+                       storage: borrowing Storage)
+    -> _borrow(storage) Self {
+    let baseAddress = unsafeBuffer.baseAddress!
+    self = GenericBufferView<Element>(baseAddress: baseAddress,
+                                      count: unsafeBuffer.count)
+    return self
+  }
+  // unsafe private API
+  @_unsafeNonescapableResult
+  init(baseAddress: Pointer, count: Int) {
+    precondition(count >= 0, "Count must not be negative")
+    self.baseAddress = baseAddress
+    self.count = count
+  } 
+}