Revert r300420 - [coroutines] Fix building of new/delete expressions when get_return_object_on_allocation_failure() is present

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@300421 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/DiagnosticSemaKinds.td

@@ -8854,11 +8854,6 @@ def err_coroutine_invalid_func_context : Error<
 def err_implied_coroutine_type_not_found : Error<
   "%0 type was not found; include <experimental/coroutine> before defining "
   "a coroutine">;
-def err_implicit_coroutine_std_nothrow_type_not_found : Error<
-  "std::nothrow was not found; include <new> before defining a coroutine which "
-  "uses get_return_object_on_allocation_failure()">;
-def err_malformed_std_nothrow : Error<
-  "std::nothrow must be a valid variable declaration">;
 def err_malformed_std_coroutine_handle : Error<
   "std::experimental::coroutine_handle must be a class template">;
 def err_coroutine_handle_missing_member : Error<
@@ -8878,7 +8873,7 @@ def err_coroutine_promise_return_ill_formed : Error<
   "%0 declares both 'return_value' and 'return_void'">;
 def note_coroutine_promise_implicit_await_transform_required_here : Note<
   "call to 'await_transform' implicitly required by 'co_await' here">;
-def note_coroutine_promise_suspend_implicitly_required : Note<
+def note_coroutine_promise_call_implicitly_required : Note<
   "call to '%select{initial_suspend|final_suspend}0' implicitly "
   "required by the %select{initial suspend point|final suspend point}0">;
 def err_coroutine_promise_unhandled_exception_required : Error<
@@ -8888,11 +8883,6 @@ def warn_coroutine_promise_unhandled_exception_required_with_exceptions : Warnin
   InGroup<Coroutine>;
 def err_coroutine_promise_get_return_object_on_allocation_failure : Error<
   "%0: 'get_return_object_on_allocation_failure()' must be a static member function">;
-def err_coroutine_promise_new_requires_nothrow : Error<
-  "%0 is required to have a non-throwing noexcept specification when the promise "
-   "type declares 'get_return_object_on_allocation_failure()'">;
-def note_coroutine_promise_call_implicitly_required : Note<
-  "call to %0 implicitly required by coroutine function here">;
 }
 
 let CategoryName = "Documentation Issue" in {

lib/Sema/SemaCoroutine.cpp

@@ -454,7 +454,7 @@ static bool actOnCoroutineBodyStart(Sema &S, Scope *SC, SourceLocation KWLoc,
                                          /*IsImplicit*/ true);
     Suspend = S.ActOnFinishFullExpr(Suspend.get());
     if (Suspend.isInvalid()) {
-      S.Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
+      S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
           << ((Name == "initial_suspend") ? 0 : 1);
       S.Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
       return StmtError();
@@ -660,39 +660,6 @@ StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E,
   return Res;
 }
 
-/// Look up the std::nothrow object.
-static Expr *buildStdNoThrowDeclRef(Sema &S, SourceLocation Loc) {
-  NamespaceDecl *Std = S.getStdNamespace();
-  assert(Std && "Should already be diagnosed");
-
-  LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
-                      Sema::LookupOrdinaryName);
-  if (!S.LookupQualifiedName(Result, Std)) {
-    // FIXME: <experimental/coroutine> should have been included already.
-    // If we require it to include <new> then this diagnostic is no longer
-    // needed.
-    S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
-    return nullptr;
-  }
-
-  // FIXME: Mark the variable as ODR used. This currently does not work
-  // likely due to the scope at in which this function is called.
-  auto *VD = Result.getAsSingle<VarDecl>();
-  if (!VD) {
-    Result.suppressDiagnostics();
-    // We found something weird. Complain about the first thing we found.
-    NamedDecl *Found = *Result.begin();
-    S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
-    return nullptr;
-  }
-
-  ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
-  if (DR.isInvalid())
-    return nullptr;
-
-  return DR.get();
-}
-
 // Find an appropriate delete for the promise.
 static FunctionDecl *findDeleteForPromise(Sema &S, SourceLocation Loc,
                                           QualType PromiseType) {
@@ -880,51 +847,23 @@ bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
   if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
     return false;
 
-  const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
-
+  // FIXME: Add nothrow_t placement arg for global alloc
+  //        if ReturnStmtOnAllocFailure != nullptr.
   // FIXME: Add support for stateful allocators.
 
   FunctionDecl *OperatorNew = nullptr;
   FunctionDecl *OperatorDelete = nullptr;
   FunctionDecl *UnusedResult = nullptr;
   bool PassAlignment = false;
-  MultiExprArg PlacementArgs = None;
 
   S.FindAllocationFunctions(Loc, SourceRange(),
                             /*UseGlobal*/ false, PromiseType,
-                            /*isArray*/ false, PassAlignment, PlacementArgs,
-                            OperatorNew, UnusedResult);
-
-  bool IsGlobalOverload =
-      OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
-  // If we didn't find a class-local new declaration and non-throwing new
-  // was is required then we need to lookup the non-throwing global operator
-  // instead.
-  if (RequiresNoThrowAlloc && (!OperatorNew || IsGlobalOverload)) {
-    auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
-    if (!StdNoThrow)
-      return false;
-    PlacementArgs = MultiExprArg(StdNoThrow);
-    OperatorNew = nullptr;
-    S.FindAllocationFunctions(Loc, SourceRange(),
-                              /*UseGlobal*/ true, PromiseType,
-                              /*isArray*/ false, PassAlignment, PlacementArgs,
-                              OperatorNew, UnusedResult);
-  }
+                            /*isArray*/ false, PassAlignment,
+                            /*PlacementArgs*/ None, OperatorNew, UnusedResult);
 
-  if (OperatorNew && RequiresNoThrowAlloc) {
-    const auto *FT = OperatorNew->getType()->getAs<FunctionProtoType>();
-    if (!FT->isNothrow(S.Context, /*ResultIfDependent*/ false)) {
-      S.Diag(OperatorNew->getLocation(),
-             diag::err_coroutine_promise_new_requires_nothrow)
-          << OperatorNew;
-      S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
-          << OperatorNew;
-      return false;
-    }
-  }
+  OperatorDelete = findDeleteForPromise(S, Loc, PromiseType);
 
-  if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr)
+  if (!OperatorDelete || !OperatorNew)
     return false;
 
   Expr *FramePtr =
@@ -940,13 +879,8 @@ bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
   if (NewRef.isInvalid())
     return false;
 
-  SmallVector<Expr *, 2> NewArgs{FrameSize};
-  for (auto Arg : PlacementArgs)
-    NewArgs.push_back(Arg);
-
   ExprResult NewExpr =
-      S.ActOnCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
-  NewExpr = S.ActOnFinishFullExpr(NewExpr.get());
+      S.ActOnCallExpr(S.getCurScope(), NewRef.get(), Loc, FrameSize, Loc);
   if (NewExpr.isInvalid())
     return false;
 
@@ -972,7 +906,6 @@ bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
 
   ExprResult DeleteExpr =
       S.ActOnCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
-  DeleteExpr = S.ActOnFinishFullExpr(DeleteExpr.get());
   if (DeleteExpr.isInvalid())
     return false;
 

test/CodeGenCoroutines/coro-alloc.cpp

@@ -19,19 +19,8 @@ struct coroutine_handle<void> {
   coroutine_handle(coroutine_handle<PromiseType>) {}
 };
 
-} // end namespace experimental
-
-struct nothrow_t {};
-constexpr nothrow_t nothrow = {};
-
-} // end namespace std
-
-// Required when get_return_object_on_allocation_failure() is defined by
-// the promise.
-using SizeT = decltype(sizeof(int));
-void* operator new(SizeT __sz, const std::nothrow_t&) noexcept;
-void  operator delete(void* __p, const std::nothrow_t&) noexcept;
-
+}
+}
 
 struct suspend_always {
   bool await_ready() { return false; }
@@ -156,7 +145,7 @@ struct std::experimental::coroutine_traits<int, promise_on_alloc_failure_tag> {
 extern "C" int f4(promise_on_alloc_failure_tag) {
   // CHECK: %[[ID:.+]] = call token @llvm.coro.id(i32 16
   // CHECK: %[[SIZE:.+]] = call i64 @llvm.coro.size.i64()
-  // CHECK: %[[MEM:.+]] = call i8* @_ZnwmRKSt9nothrow_t(i64 %[[SIZE]], %"struct.std::nothrow_t"* dereferenceable(1) @_ZStL7nothrow)
+  // CHECK: %[[MEM:.+]] = call i8* @_Znwm(i64 %[[SIZE]])
   // CHECK: %[[OK:.+]] = icmp ne i8* %[[MEM]], null
   // CHECK: br i1 %[[OK]], label %[[OKBB:.+]], label %[[ERRBB:.+]]
 

test/SemaCXX/coroutines.cpp

@@ -654,18 +654,6 @@ float badly_specialized_coro_handle() { // expected-error {{std::experimental::c
   co_return; //expected-note {{function is a coroutine due to use of 'co_return' here}}
 }
 
-namespace std {
-  struct nothrow_t {};
-  constexpr nothrow_t nothrow = {};
-}
-
-using SizeT = decltype(sizeof(int));
-
-void* operator new(SizeT __sz, const std::nothrow_t&) noexcept;
-void  operator delete(void* __p, const std::nothrow_t&) noexcept;
-
-
-
 struct promise_on_alloc_failure_tag {};
 
 template<>
@@ -706,43 +694,3 @@ coro<T> dependent_private_alloc_failure_handler(T) {
 }
 template coro<bad_promise_11> dependent_private_alloc_failure_handler(bad_promise_11);
 // expected-note@-1 {{requested here}}
-
-struct bad_promise_12 {
-  coro<bad_promise_12> get_return_object();
-  suspend_always initial_suspend();
-  suspend_always final_suspend();
-  void unhandled_exception();
-  void return_void();
-  static coro<bad_promise_12> get_return_object_on_allocation_failure();
-
-  static void* operator new(SizeT);
-  // expected-error@-1 2 {{'operator new' is required to have a non-throwing noexcept specification when the promise type declares 'get_return_object_on_allocation_failure()'}}
-};
-coro<bad_promise_12> throwing_in_class_new() { // expected-note {{call to 'operator new' implicitly required by coroutine function here}}
-  co_return;
-}
-
-template <class T>
-coro<T> dependent_throwing_in_class_new(T) { // expected-note {{call to 'operator new' implicitly required by coroutine function here}}
-   co_return;
-}
-template coro<bad_promise_12> dependent_throwing_in_class_new(bad_promise_12); // expected-note {{requested here}}
-
-
-struct good_promise_13 {
-  coro<good_promise_13> get_return_object();
-  suspend_always initial_suspend();
-  suspend_always final_suspend();
-  void unhandled_exception();
-  void return_void();
-  static coro<good_promise_13> get_return_object_on_allocation_failure();
-};
-coro<good_promise_13> uses_nothrow_new() {
-  co_return;
-}
-
-template <class T>
-coro<T> dependent_uses_nothrow_new(T) {
-   co_return;
-}
-template coro<good_promise_13> dependent_uses_nothrow_new(good_promise_13);