1 files changed, 99 insertions, 19 deletions

diff --git a/clang/lib/Sema/SemaCoroutine.cpp b/clang/lib/Sema/SemaCoroutine.cpp
index c709a1a723d..be89cd16deb 100644
--- a/clang/lib/Sema/SemaCoroutine.cpp
+++ b/clang/lib/Sema/SemaCoroutine.cpp
@@ -373,7 +373,6 @@ static ExprResult buildPromiseCall(Sema &S, VarDecl *Promise,
   if (PromiseRef.isInvalid())
     return ExprError();
 
-  // Call 'yield_value', passing in E.
   return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
 }
 
@@ -780,7 +779,8 @@ bool CoroutineStmtBuilder::buildDependentStatements() {
   assert(!this->IsPromiseDependentType &&
          "coroutine cannot have a dependent promise type");
   this->IsValid = makeOnException() && makeOnFallthrough() &&
-                  makeReturnOnAllocFailure() && makeNewAndDeleteExpr();
+                  makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
+                  makeNewAndDeleteExpr();
   return this->IsValid;
 }
 
@@ -857,15 +857,16 @@ bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
   if (ReturnObjectOnAllocationFailure.isInvalid())
     return false;
 
-  // FIXME: ActOnReturnStmt expects a scope that is inside of the function, due
-  //   to CheckJumpOutOfSEHFinally(*this, ReturnLoc, *CurScope->getFnParent());
-  //   S.getCurScope()->getFnParent() == nullptr at ActOnFinishFunctionBody when
-  //   CoroutineBodyStmt is built. Figure it out and fix it.
-  //   Use BuildReturnStmt here to unbreak sanitized tests. (Gor:3/27/2017)
   StmtResult ReturnStmt =
       S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
-  if (ReturnStmt.isInvalid())
+  if (ReturnStmt.isInvalid()) {
+    S.Diag(Found.getFoundDecl()->getLocation(),
+           diag::note_promise_member_declared_here)
+        << DN.getAsString();
+    S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
+        << Fn.getFirstCoroutineStmtKeyword();
     return false;
+  }
 
   this->ReturnStmtOnAllocFailure = ReturnStmt.get();
   return true;
@@ -1047,27 +1048,106 @@ bool CoroutineStmtBuilder::makeOnException() {
 }
 
 bool CoroutineStmtBuilder::makeReturnObject() {
-
   // Build implicit 'p.get_return_object()' expression and form initialization
   // of return type from it.
   ExprResult ReturnObject =
       buildPromiseCall(S, Fn.CoroutinePromise, Loc, "get_return_object", None);
   if (ReturnObject.isInvalid())
     return false;
-  QualType RetType = FD.getReturnType();
-  if (!RetType->isDependentType()) {
-    InitializedEntity Entity =
-        InitializedEntity::InitializeResult(Loc, RetType, false);
-    ReturnObject = S.PerformMoveOrCopyInitialization(Entity, nullptr, RetType,
-                                                   ReturnObject.get());
-    if (ReturnObject.isInvalid())
+
+  this->ReturnValue = ReturnObject.get();
+  return true;
+}
+
+static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn) {
+  if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
+    auto *MethodDecl = MbrRef->getMethodDecl();
+    S.Diag(MethodDecl->getLocation(), diag::note_promise_member_declared_here)
+        << MethodDecl->getName();
+  }
+  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
+      << Fn.getFirstCoroutineStmtKeyword();
+}
+
+bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
+  assert(!IsPromiseDependentType &&
+         "cannot make statement while the promise type is dependent");
+  assert(this->ReturnValue && "ReturnValue must be already formed");
+
+  QualType const GroType = this->ReturnValue->getType();
+  assert(!GroType->isDependentType() &&
+         "get_return_object type must no longer be dependent");
+
+  QualType const FnRetType = FD.getReturnType();
+  assert(!FnRetType->isDependentType() &&
+         "get_return_object type must no longer be dependent");
+
+  if (FnRetType->isVoidType()) {
+    ExprResult Res = S.ActOnFinishFullExpr(this->ReturnValue, Loc);
+    if (Res.isInvalid())
       return false;
+
+    this->ResultDecl = Res.get();
+    return true;
   }
-  ReturnObject = S.ActOnFinishFullExpr(ReturnObject.get(), Loc);
-  if (ReturnObject.isInvalid())
+
+  if (GroType->isVoidType()) {
+    // Trigger a nice error message.
+    InitializedEntity Entity =
+        InitializedEntity::InitializeResult(Loc, FnRetType, false);
+    S.PerformMoveOrCopyInitialization(Entity, nullptr, FnRetType, ReturnValue);
+    noteMemberDeclaredHere(S, ReturnValue, Fn);
     return false;
+  }
 
-  this->ReturnValue = ReturnObject.get();
+  auto *GroDecl = VarDecl::Create(
+      S.Context, &FD, FD.getLocation(), FD.getLocation(),
+      &S.PP.getIdentifierTable().get("__coro_gro"), GroType,
+      S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
+
+  S.CheckVariableDeclarationType(GroDecl);
+  if (GroDecl->isInvalidDecl())
+    return false;
+
+  InitializedEntity Entity = InitializedEntity::InitializeVariable(GroDecl);
+  ExprResult Res = S.PerformMoveOrCopyInitialization(Entity, nullptr, GroType,
+                                                     this->ReturnValue);
+  if (Res.isInvalid())
+    return false;
+
+  Res = S.ActOnFinishFullExpr(Res.get());
+  if (Res.isInvalid())
+    return false;
+
+  if (GroType == FnRetType) {
+    GroDecl->setNRVOVariable(true);
+  }
+
+  S.AddInitializerToDecl(GroDecl, Res.get(),
+                         /*DirectInit=*/false);
+
+  S.FinalizeDeclaration(GroDecl);
+
+  // Form a declaration statement for the return declaration, so that AST
+  // visitors can more easily find it.
+  StmtResult GroDeclStmt =
+      S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
+  if (GroDeclStmt.isInvalid())
+    return false;
+
+  this->ResultDecl = GroDeclStmt.get();
+
+  ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
+  if (declRef.isInvalid())
+    return false;
+
+  StmtResult ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
+  if (ReturnStmt.isInvalid()) {
+    noteMemberDeclaredHere(S, ReturnValue, Fn);
+    return false;
+  }
+
+  this->ReturnStmt = ReturnStmt.get();
   return true;
 }