Statement setter for last element

Author: maustinstar

include/swift/AST/Stmt.h

@@ -180,6 +180,7 @@ class BraceStmt final : public Stmt,
   ASTNode getLastElement() const { return getElements().back(); }
 
   void setFirstElement(ASTNode node) { getElements().front() = node; }
+  void setLastElement(ASTNode node) { getElements().back() = node; }
 
   /// The elements contained within the BraceStmt.
   MutableArrayRef<ASTNode> getElements() {

lib/AST/Decl.cpp

@@ -684,7 +684,7 @@ Expr *AbstractFunctionDecl::getSingleExpressionBody() const {
   assert(hasSingleExpressionBody() && "Not a single-expression body");
   auto braceStmt = getBody();
   assert(braceStmt != nullptr && "No body currently available.");
-  auto body = getBody()->getElements().back();
+  auto body = getBody()->getLastElement();
   if (auto *stmt = body.dyn_cast<Stmt *>()) {
     if (auto *returnStmt = dyn_cast<ReturnStmt>(stmt)) {
       return returnStmt->getResult();
@@ -701,7 +701,7 @@ Expr *AbstractFunctionDecl::getSingleExpressionBody() const {
 
 void AbstractFunctionDecl::setSingleExpressionBody(Expr *NewBody) {
   assert(hasSingleExpressionBody() && "Not a single-expression body");
-  auto body = getBody()->getElements().back();
+  auto body = getBody()->getLastElement();
   if (auto *stmt = body.dyn_cast<Stmt *>()) {
     if (auto *returnStmt = dyn_cast<ReturnStmt>(stmt)) {
       returnStmt->setResult(NewBody);
@@ -717,7 +717,7 @@ void AbstractFunctionDecl::setSingleExpressionBody(Expr *NewBody) {
       return;
     }
   }
-  getBody()->getElements().back() = NewBody;
+  getBody()->setLastElement(NewBody);
 }
 
 bool AbstractStorageDecl::isTransparent() const {

lib/IDE/CodeCompletion.cpp

@@ -6107,7 +6107,7 @@ static void undoSingleExpressionReturn(DeclContext *DC) {
     if (!RS || !RS->isImplicit())
       return false;
 
-    BS->getElements().back() = RS->getResult();
+    BS->setLastElement(RS->getResult());
     return true;
   };
 

lib/Parse/ParseDecl.cpp

@@ -6683,15 +6683,15 @@ BraceStmt *Parser::parseAbstractFunctionBodyImpl(AbstractFunctionDecl *AFD) {
       }
       if (isa<FuncDecl>(AFD)) {
         auto RS = new (Context) ReturnStmt(SourceLoc(), E);
-        BS->getElements().back() = RS;
+        BS->setLastElement(RS);
         AFD->setHasSingleExpressionBody();
         AFD->setSingleExpressionBody(E);
       } else if (auto *F = dyn_cast<ConstructorDecl>(AFD)) {
         if (F->isFailable() && isa<NilLiteralExpr>(E)) {
           // If it's a nil literal, just insert return.  This is the only
           // legal thing to return.
           auto RS = new (Context) ReturnStmt(E->getStartLoc(), E);
-          BS->getElements().back() = RS;
+          BS->setLastElement(RS);
           AFD->setHasSingleExpressionBody();
           AFD->setSingleExpressionBody(E);
         }

lib/Sema/TypeCheckStmt.cpp

@@ -1926,7 +1926,7 @@ bool TypeCheckASTNodeAtLocRequest::evaluate(Evaluator &evaluator,
                 func->getResultInterfaceType()->isVoid()) {
        // The function returns void.  We don't need an explicit return, no matter
        // what the type of the expression is.  Take the inserted return back out.
-      func->getBody()->getElements().back() = func->getSingleExpressionBody();
+      func->getBody()->setLastElement(func->getSingleExpressionBody());
     }
   }
 
@@ -1991,7 +1991,7 @@ TypeCheckFunctionBodyRequest::evaluate(Evaluator &evaluator,
                func->getResultInterfaceType()->isVoid()) {
       // The function returns void.  We don't need an explicit return, no matter
       // what the type of the expression is.  Take the inserted return back out.
-      body->getElements().back() = func->getSingleExpressionBody();
+      body->setLastElement(func->getSingleExpressionBody());
     }
   } else if (isa<ConstructorDecl>(AFD) &&
              (body->empty() ||
@@ -2025,12 +2025,12 @@ TypeCheckFunctionBodyRequest::evaluate(Evaluator &evaluator,
   // that we have eagerly converted something like `{ fatalError() }`
   // into `{ return fatalError() }` that has to be corrected here.
   if (isa<FuncDecl>(AFD) && cast<FuncDecl>(AFD)->hasSingleExpressionBody()) {
-    if (auto *stmt = body->getElements().back().dyn_cast<Stmt *>()) {
+    if (auto *stmt = body->getLastElement().dyn_cast<Stmt *>()) {
       if (auto *retStmt = dyn_cast<ReturnStmt>(stmt)) {
         if (retStmt->isImplicit() && retStmt->hasResult()) {
           auto returnType = retStmt->getResult()->getType();
           if (returnType && returnType->isUninhabited())
-            body->getElements().back() = retStmt->getResult();
+            body->setLastElement(retStmt->getResult());
         }
       }
     }