1 files changed, 26 insertions, 81 deletions

diff --git a/clang/lib/CodeGen/CGCoroutine.cpp b/clang/lib/CodeGen/CGCoroutine.cpp
index c1763cbbc5a0..594c7d49df3c 100644
--- a/clang/lib/CodeGen/CGCoroutine.cpp
+++ b/clang/lib/CodeGen/CGCoroutine.cpp
@@ -238,8 +238,8 @@ static LValueOrRValue emitSuspendExpression(CodeGenFunction &CGF, CGCoroData &Co
     auto Loc = S.getResumeExpr()->getExprLoc();
     auto *Catch = new (CGF.getContext())
         CXXCatchStmt(Loc, /*exDecl=*/nullptr, Coro.ExceptionHandler);
-    auto *TryBody =
-        CompoundStmt::Create(CGF.getContext(), S.getResumeExpr(), Loc, Loc);
+    auto *TryBody = CompoundStmt::Create(CGF.getContext(), S.getResumeExpr(),
+                                         FPOptionsOverride(), Loc, Loc);
     TryStmt = CXXTryStmt::Create(CGF.getContext(), Loc, TryBody, Catch);
     CGF.EnterCXXTryStmt(*TryStmt);
   }
@@ -465,72 +465,6 @@ struct CallCoroDelete final : public EHScopeStack::Cleanup {
 };
 }
 
-namespace {
-struct GetReturnObjectManager {
-  CodeGenFunction &CGF;
-  CGBuilderTy &Builder;
-  const CoroutineBodyStmt &S;
-
-  Address GroActiveFlag;
-  CodeGenFunction::AutoVarEmission GroEmission;
-
-  GetReturnObjectManager(CodeGenFunction &CGF, const CoroutineBodyStmt &S)
-      : CGF(CGF), Builder(CGF.Builder), S(S), GroActiveFlag(Address::invalid()),
-        GroEmission(CodeGenFunction::AutoVarEmission::invalid()) {}
-
-  // The gro variable has to outlive coroutine frame and coroutine promise, but,
-  // it can only be initialized after coroutine promise was created, thus, we
-  // split its emission in two parts. EmitGroAlloca emits an alloca and sets up
-  // cleanups. Later when coroutine promise is available we initialize the gro
-  // and sets the flag that the cleanup is now active.
-
-  void EmitGroAlloca() {
-    auto *GroDeclStmt = dyn_cast<DeclStmt>(S.getResultDecl());
-    if (!GroDeclStmt) {
-      // If get_return_object returns void, no need to do an alloca.
-      return;
-    }
-
-    auto *GroVarDecl = cast<VarDecl>(GroDeclStmt->getSingleDecl());
-
-    // Set GRO flag that it is not initialized yet
-    GroActiveFlag =
-      CGF.CreateTempAlloca(Builder.getInt1Ty(), CharUnits::One(), "gro.active");
-    Builder.CreateStore(Builder.getFalse(), GroActiveFlag);
-
-    GroEmission = CGF.EmitAutoVarAlloca(*GroVarDecl);
-
-    // Remember the top of EHStack before emitting the cleanup.
-    auto old_top = CGF.EHStack.stable_begin();
-    CGF.EmitAutoVarCleanups(GroEmission);
-    auto top = CGF.EHStack.stable_begin();
-
-    // Make the cleanup conditional on gro.active
-    for (auto b = CGF.EHStack.find(top), e = CGF.EHStack.find(old_top);
-      b != e; b++) {
-      if (auto *Cleanup = dyn_cast<EHCleanupScope>(&*b)) {
-        assert(!Cleanup->hasActiveFlag() && "cleanup already has active flag?");
-        Cleanup->setActiveFlag(GroActiveFlag);
-        Cleanup->setTestFlagInEHCleanup();
-        Cleanup->setTestFlagInNormalCleanup();
-      }
-    }
-  }
-
-  void EmitGroInit() {
-    if (!GroActiveFlag.isValid()) {
-      // No Gro variable was allocated. Simply emit the call to
-      // get_return_object.
-      CGF.EmitStmt(S.getResultDecl());
-      return;
-    }
-
-    CGF.EmitAutoVarInit(GroEmission);
-    Builder.CreateStore(Builder.getTrue(), GroActiveFlag);
-  }
-};
-}
-
 static void emitBodyAndFallthrough(CodeGenFunction &CGF,
                                    const CoroutineBodyStmt &S, Stmt *Body) {
   CGF.EmitStmt(Body);
@@ -597,13 +531,6 @@ void CodeGenFunction::EmitCoroutineBody(const CoroutineBodyStmt &S) {
       CGM.getIntrinsic(llvm::Intrinsic::coro_begin), {CoroId, Phi});
   CurCoro.Data->CoroBegin = CoroBegin;
 
-  // We need to emit `get_­return_­object` first. According to:
-  // [dcl.fct.def.coroutine]p7
-  // The call to get_­return_­object is sequenced before the call to
-  // initial_­suspend and is invoked at most once.
-  GetReturnObjectManager GroManager(*this, S);
-  GroManager.EmitGroAlloca();
-
   CurCoro.Data->CleanupJD = getJumpDestInCurrentScope(RetBB);
   {
     CGDebugInfo *DI = getDebugInfo();
@@ -641,8 +568,23 @@ void CodeGenFunction::EmitCoroutineBody(const CoroutineBodyStmt &S) {
     // promise local variable was not emitted yet.
     CoroId->setArgOperand(1, PromiseAddrVoidPtr);
 
-    // Now we have the promise, initialize the GRO
-    GroManager.EmitGroInit();
+    // ReturnValue should be valid as long as the coroutine's return type
+    // is not void. The assertion could help us to reduce the check later.
+    assert(ReturnValue.isValid() == (bool)S.getReturnStmt());
+    // Now we have the promise, initialize the GRO.
+    // We need to emit `get_return_object` first. According to:
+    // [dcl.fct.def.coroutine]p7
+    // The call to get_return_­object is sequenced before the call to
+    // initial_suspend and is invoked at most once.
+    //
+    // So we couldn't emit return value when we emit return statment,
+    // otherwise the call to get_return_object wouldn't be in front
+    // of initial_suspend.
+    if (ReturnValue.isValid()) {
+      EmitAnyExprToMem(S.getReturnValue(), ReturnValue,
+                       S.getReturnValue()->getType().getQualifiers(),
+                       /*IsInit*/ true);
+    }
 
     EHStack.pushCleanup<CallCoroEnd>(EHCleanup);
 
@@ -705,12 +647,15 @@ void CodeGenFunction::EmitCoroutineBody(const CoroutineBodyStmt &S) {
   llvm::Function *CoroEnd = CGM.getIntrinsic(llvm::Intrinsic::coro_end);
   Builder.CreateCall(CoroEnd, {NullPtr, Builder.getFalse()});
 
-  if (Stmt *Ret = S.getReturnStmt())
+  if (Stmt *Ret = S.getReturnStmt()) {
+    // Since we already emitted the return value above, so we shouldn't
+    // emit it again here.
+    cast<ReturnStmt>(Ret)->setRetValue(nullptr);
     EmitStmt(Ret);
+  }
 
-  // LLVM require the frontend to add the function attribute. See
-  // Coroutines.rst.
-  CurFn->addFnAttr("coroutine.presplit", "0");
+  // LLVM require the frontend to mark the coroutine.
+  CurFn->setPresplitCoroutine();
 }
 
 // Emit coroutine intrinsic and patch up arguments of the token type.