clang  9.0.0svn
SemaCoroutine.cpp
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1 //===--- SemaCoroutines.cpp - Semantic Analysis for Coroutines ------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements semantic analysis for C++ Coroutines.
10 //
11 // This file contains references to sections of the Coroutines TS, which
12 // can be found at http://wg21.link/coroutines.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "CoroutineStmtBuilder.h"
17 #include "clang/AST/ASTLambda.h"
18 #include "clang/AST/Decl.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/StmtCXX.h"
21 #include "clang/Lex/Preprocessor.h"
23 #include "clang/Sema/Overload.h"
24 #include "clang/Sema/ScopeInfo.h"
26 
27 using namespace clang;
28 using namespace sema;
29 
30 static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
31  SourceLocation Loc, bool &Res) {
33  LookupResult LR(S, DN, Loc, Sema::LookupMemberName);
34  // Suppress diagnostics when a private member is selected. The same warnings
35  // will be produced again when building the call.
37  Res = S.LookupQualifiedName(LR, RD);
38  return LR;
39 }
40 
41 static bool lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
42  SourceLocation Loc) {
43  bool Res;
44  lookupMember(S, Name, RD, Loc, Res);
45  return Res;
46 }
47 
48 /// Look up the std::coroutine_traits<...>::promise_type for the given
49 /// function type.
51  SourceLocation KwLoc) {
52  const FunctionProtoType *FnType = FD->getType()->castAs<FunctionProtoType>();
53  const SourceLocation FuncLoc = FD->getLocation();
54  // FIXME: Cache std::coroutine_traits once we've found it.
56  if (!StdExp) {
57  S.Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
58  << "std::experimental::coroutine_traits";
59  return QualType();
60  }
61 
62  ClassTemplateDecl *CoroTraits = S.lookupCoroutineTraits(KwLoc, FuncLoc);
63  if (!CoroTraits) {
64  return QualType();
65  }
66 
67  // Form template argument list for coroutine_traits<R, P1, P2, ...> according
68  // to [dcl.fct.def.coroutine]3
69  TemplateArgumentListInfo Args(KwLoc, KwLoc);
70  auto AddArg = [&](QualType T) {
73  };
74  AddArg(FnType->getReturnType());
75  // If the function is a non-static member function, add the type
76  // of the implicit object parameter before the formal parameters.
77  if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
78  if (MD->isInstance()) {
79  // [over.match.funcs]4
80  // For non-static member functions, the type of the implicit object
81  // parameter is
82  // -- "lvalue reference to cv X" for functions declared without a
83  // ref-qualifier or with the & ref-qualifier
84  // -- "rvalue reference to cv X" for functions declared with the &&
85  // ref-qualifier
86  QualType T = MD->getThisType()->getAs<PointerType>()->getPointeeType();
87  T = FnType->getRefQualifier() == RQ_RValue
89  : S.Context.getLValueReferenceType(T, /*SpelledAsLValue*/ true);
90  AddArg(T);
91  }
92  }
93  for (QualType T : FnType->getParamTypes())
94  AddArg(T);
95 
96  // Build the template-id.
97  QualType CoroTrait =
98  S.CheckTemplateIdType(TemplateName(CoroTraits), KwLoc, Args);
99  if (CoroTrait.isNull())
100  return QualType();
101  if (S.RequireCompleteType(KwLoc, CoroTrait,
102  diag::err_coroutine_type_missing_specialization))
103  return QualType();
104 
105  auto *RD = CoroTrait->getAsCXXRecordDecl();
106  assert(RD && "specialization of class template is not a class?");
107 
108  // Look up the ::promise_type member.
109  LookupResult R(S, &S.PP.getIdentifierTable().get("promise_type"), KwLoc,
111  S.LookupQualifiedName(R, RD);
112  auto *Promise = R.getAsSingle<TypeDecl>();
113  if (!Promise) {
114  S.Diag(FuncLoc,
115  diag::err_implied_std_coroutine_traits_promise_type_not_found)
116  << RD;
117  return QualType();
118  }
119  // The promise type is required to be a class type.
120  QualType PromiseType = S.Context.getTypeDeclType(Promise);
121 
122  auto buildElaboratedType = [&]() {
123  auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, StdExp);
124  NNS = NestedNameSpecifier::Create(S.Context, NNS, false,
125  CoroTrait.getTypePtr());
126  return S.Context.getElaboratedType(ETK_None, NNS, PromiseType);
127  };
128 
129  if (!PromiseType->getAsCXXRecordDecl()) {
130  S.Diag(FuncLoc,
131  diag::err_implied_std_coroutine_traits_promise_type_not_class)
132  << buildElaboratedType();
133  return QualType();
134  }
135  if (S.RequireCompleteType(FuncLoc, buildElaboratedType(),
136  diag::err_coroutine_promise_type_incomplete))
137  return QualType();
138 
139  return PromiseType;
140 }
141 
142 /// Look up the std::experimental::coroutine_handle<PromiseType>.
144  SourceLocation Loc) {
145  if (PromiseType.isNull())
146  return QualType();
147 
149  assert(StdExp && "Should already be diagnosed");
150 
151  LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_handle"),
153  if (!S.LookupQualifiedName(Result, StdExp)) {
154  S.Diag(Loc, diag::err_implied_coroutine_type_not_found)
155  << "std::experimental::coroutine_handle";
156  return QualType();
157  }
158 
159  ClassTemplateDecl *CoroHandle = Result.getAsSingle<ClassTemplateDecl>();
160  if (!CoroHandle) {
161  Result.suppressDiagnostics();
162  // We found something weird. Complain about the first thing we found.
163  NamedDecl *Found = *Result.begin();
164  S.Diag(Found->getLocation(), diag::err_malformed_std_coroutine_handle);
165  return QualType();
166  }
167 
168  // Form template argument list for coroutine_handle<Promise>.
169  TemplateArgumentListInfo Args(Loc, Loc);
171  TemplateArgument(PromiseType),
172  S.Context.getTrivialTypeSourceInfo(PromiseType, Loc)));
173 
174  // Build the template-id.
175  QualType CoroHandleType =
176  S.CheckTemplateIdType(TemplateName(CoroHandle), Loc, Args);
177  if (CoroHandleType.isNull())
178  return QualType();
179  if (S.RequireCompleteType(Loc, CoroHandleType,
180  diag::err_coroutine_type_missing_specialization))
181  return QualType();
182 
183  return CoroHandleType;
184 }
185 
187  StringRef Keyword) {
188  // 'co_await' and 'co_yield' are not permitted in unevaluated operands,
189  // such as subexpressions of \c sizeof.
190  //
191  // [expr.await]p2, emphasis added: "An await-expression shall appear only in
192  // a *potentially evaluated* expression within the compound-statement of a
193  // function-body outside of a handler [...] A context within a function where
194  // an await-expression can appear is called a suspension context of the
195  // function." And per [expr.yield]p1: "A yield-expression shall appear only
196  // within a suspension context of a function."
197  if (S.isUnevaluatedContext()) {
198  S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
199  return false;
200  }
201 
202  // Per [expr.await]p2, any other usage must be within a function.
203  // FIXME: This also covers [expr.await]p2: "An await-expression shall not
204  // appear in a default argument." But the diagnostic QoI here could be
205  // improved to inform the user that default arguments specifically are not
206  // allowed.
207  auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
208  if (!FD) {
209  S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
210  ? diag::err_coroutine_objc_method
211  : diag::err_coroutine_outside_function) << Keyword;
212  return false;
213  }
214 
215  // An enumeration for mapping the diagnostic type to the correct diagnostic
216  // selection index.
217  enum InvalidFuncDiag {
218  DiagCtor = 0,
219  DiagDtor,
220  DiagCopyAssign,
221  DiagMoveAssign,
222  DiagMain,
223  DiagConstexpr,
224  DiagAutoRet,
225  DiagVarargs,
226  };
227  bool Diagnosed = false;
228  auto DiagInvalid = [&](InvalidFuncDiag ID) {
229  S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
230  Diagnosed = true;
231  return false;
232  };
233 
234  // Diagnose when a constructor, destructor, copy/move assignment operator,
235  // or the function 'main' are declared as a coroutine.
236  auto *MD = dyn_cast<CXXMethodDecl>(FD);
237  // [class.ctor]p6: "A constructor shall not be a coroutine."
238  if (MD && isa<CXXConstructorDecl>(MD))
239  return DiagInvalid(DiagCtor);
240  // [class.dtor]p17: "A destructor shall not be a coroutine."
241  else if (MD && isa<CXXDestructorDecl>(MD))
242  return DiagInvalid(DiagDtor);
243  // N4499 [special]p6: "A special member function shall not be a coroutine."
244  // Per C++ [special]p1, special member functions are the "default constructor,
245  // copy constructor and copy assignment operator, move constructor and move
246  // assignment operator, and destructor."
247  else if (MD && MD->isCopyAssignmentOperator())
248  return DiagInvalid(DiagCopyAssign);
249  else if (MD && MD->isMoveAssignmentOperator())
250  return DiagInvalid(DiagMoveAssign);
251  // [basic.start.main]p3: "The function main shall not be a coroutine."
252  else if (FD->isMain())
253  return DiagInvalid(DiagMain);
254 
255  // Emit a diagnostics for each of the following conditions which is not met.
256  // [expr.const]p2: "An expression e is a core constant expression unless the
257  // evaluation of e [...] would evaluate one of the following expressions:
258  // [...] an await-expression [...] a yield-expression."
259  if (FD->isConstexpr())
260  DiagInvalid(DiagConstexpr);
261  // [dcl.spec.auto]p15: "A function declared with a return type that uses a
262  // placeholder type shall not be a coroutine."
263  if (FD->getReturnType()->isUndeducedType())
264  DiagInvalid(DiagAutoRet);
265  // [dcl.fct.def.coroutine]p1: "The parameter-declaration-clause of the
266  // coroutine shall not terminate with an ellipsis that is not part of a
267  // parameter-declaration."
268  if (FD->isVariadic())
269  DiagInvalid(DiagVarargs);
270 
271  return !Diagnosed;
272 }
273 
275  SourceLocation Loc) {
276  DeclarationName OpName =
277  SemaRef.Context.DeclarationNames.getCXXOperatorName(OO_Coawait);
278  LookupResult Operators(SemaRef, OpName, SourceLocation(),
280  SemaRef.LookupName(Operators, S);
281 
282  assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
283  const auto &Functions = Operators.asUnresolvedSet();
284  bool IsOverloaded =
285  Functions.size() > 1 ||
286  (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
287  Expr *CoawaitOp = UnresolvedLookupExpr::Create(
288  SemaRef.Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(),
289  DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded,
290  Functions.begin(), Functions.end());
291  assert(CoawaitOp);
292  return CoawaitOp;
293 }
294 
295 /// Build a call to 'operator co_await' if there is a suitable operator for
296 /// the given expression.
298  Expr *E,
299  UnresolvedLookupExpr *Lookup) {
300  UnresolvedSet<16> Functions;
301  Functions.append(Lookup->decls_begin(), Lookup->decls_end());
302  return SemaRef.CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E);
303 }
304 
306  SourceLocation Loc, Expr *E) {
307  ExprResult R = buildOperatorCoawaitLookupExpr(SemaRef, S, Loc);
308  if (R.isInvalid())
309  return ExprError();
310  return buildOperatorCoawaitCall(SemaRef, Loc, E,
311  cast<UnresolvedLookupExpr>(R.get()));
312 }
313 
315  MultiExprArg CallArgs) {
316  StringRef Name = S.Context.BuiltinInfo.getName(Id);
318  S.LookupName(R, S.TUScope, /*AllowBuiltinCreation=*/true);
319 
320  auto *BuiltInDecl = R.getAsSingle<FunctionDecl>();
321  assert(BuiltInDecl && "failed to find builtin declaration");
322 
323  ExprResult DeclRef =
324  S.BuildDeclRefExpr(BuiltInDecl, BuiltInDecl->getType(), VK_LValue, Loc);
325  assert(DeclRef.isUsable() && "Builtin reference cannot fail");
326 
327  ExprResult Call =
328  S.ActOnCallExpr(/*Scope=*/nullptr, DeclRef.get(), Loc, CallArgs, Loc);
329 
330  assert(!Call.isInvalid() && "Call to builtin cannot fail!");
331  return Call.get();
332 }
333 
335  SourceLocation Loc) {
336  QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
337  if (CoroHandleType.isNull())
338  return ExprError();
339 
340  DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType);
341  LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc,
343  if (!S.LookupQualifiedName(Found, LookupCtx)) {
344  S.Diag(Loc, diag::err_coroutine_handle_missing_member)
345  << "from_address";
346  return ExprError();
347  }
348 
349  Expr *FramePtr =
350  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
351 
352  CXXScopeSpec SS;
353  ExprResult FromAddr =
354  S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
355  if (FromAddr.isInvalid())
356  return ExprError();
357 
358  return S.ActOnCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc);
359 }
360 
362  enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
363  Expr *Results[3];
365  bool IsInvalid;
366 };
367 
369  StringRef Name, MultiExprArg Args) {
370  DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc);
371 
372  // FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&.
373  CXXScopeSpec SS;
375  Base, Base->getType(), Loc, /*IsPtr=*/false, SS,
376  SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr,
377  /*Scope=*/nullptr);
378  if (Result.isInvalid())
379  return ExprError();
380 
381  // We meant exactly what we asked for. No need for typo correction.
382  if (auto *TE = dyn_cast<TypoExpr>(Result.get())) {
383  S.clearDelayedTypo(TE);
384  S.Diag(Loc, diag::err_no_member)
385  << NameInfo.getName() << Base->getType()->getAsCXXRecordDecl()
386  << Base->getSourceRange();
387  return ExprError();
388  }
389 
390  return S.ActOnCallExpr(nullptr, Result.get(), Loc, Args, Loc, nullptr);
391 }
392 
393 // See if return type is coroutine-handle and if so, invoke builtin coro-resume
394 // on its address. This is to enable experimental support for coroutine-handle
395 // returning await_suspend that results in a guaranteed tail call to the target
396 // coroutine.
397 static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
398  SourceLocation Loc) {
399  if (RetType->isReferenceType())
400  return nullptr;
401  Type const *T = RetType.getTypePtr();
402  if (!T->isClassType() && !T->isStructureType())
403  return nullptr;
404 
405  // FIXME: Add convertability check to coroutine_handle<>. Possibly via
406  // EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment
407  // a private function in SemaExprCXX.cpp
408 
409  ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", None);
410  if (AddressExpr.isInvalid())
411  return nullptr;
412 
413  Expr *JustAddress = AddressExpr.get();
414  // FIXME: Check that the type of AddressExpr is void*
415  return buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_resume,
416  JustAddress);
417 }
418 
419 /// Build calls to await_ready, await_suspend, and await_resume for a co_await
420 /// expression.
422  SourceLocation Loc, Expr *E) {
423  OpaqueValueExpr *Operand = new (S.Context)
424  OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
425 
426  // Assume invalid until we see otherwise.
427  ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/true};
428 
429  ExprResult CoroHandleRes = buildCoroutineHandle(S, CoroPromise->getType(), Loc);
430  if (CoroHandleRes.isInvalid())
431  return Calls;
432  Expr *CoroHandle = CoroHandleRes.get();
433 
434  const StringRef Funcs[] = {"await_ready", "await_suspend", "await_resume"};
435  MultiExprArg Args[] = {None, CoroHandle, None};
436  for (size_t I = 0, N = llvm::array_lengthof(Funcs); I != N; ++I) {
437  ExprResult Result = buildMemberCall(S, Operand, Loc, Funcs[I], Args[I]);
438  if (Result.isInvalid())
439  return Calls;
440  Calls.Results[I] = Result.get();
441  }
442 
443  // Assume the calls are valid; all further checking should make them invalid.
444  Calls.IsInvalid = false;
445 
447  CallExpr *AwaitReady = cast<CallExpr>(Calls.Results[ACT::ACT_Ready]);
448  if (!AwaitReady->getType()->isDependentType()) {
449  // [expr.await]p3 [...]
450  // — await-ready is the expression e.await_ready(), contextually converted
451  // to bool.
452  ExprResult Conv = S.PerformContextuallyConvertToBool(AwaitReady);
453  if (Conv.isInvalid()) {
454  S.Diag(AwaitReady->getDirectCallee()->getBeginLoc(),
455  diag::note_await_ready_no_bool_conversion);
456  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
457  << AwaitReady->getDirectCallee() << E->getSourceRange();
458  Calls.IsInvalid = true;
459  }
460  Calls.Results[ACT::ACT_Ready] = Conv.get();
461  }
462  CallExpr *AwaitSuspend = cast<CallExpr>(Calls.Results[ACT::ACT_Suspend]);
463  if (!AwaitSuspend->getType()->isDependentType()) {
464  // [expr.await]p3 [...]
465  // - await-suspend is the expression e.await_suspend(h), which shall be
466  // a prvalue of type void or bool.
467  QualType RetType = AwaitSuspend->getCallReturnType(S.Context);
468 
469  // Experimental support for coroutine_handle returning await_suspend.
470  if (Expr *TailCallSuspend = maybeTailCall(S, RetType, AwaitSuspend, Loc))
471  Calls.Results[ACT::ACT_Suspend] = TailCallSuspend;
472  else {
473  // non-class prvalues always have cv-unqualified types
474  if (RetType->isReferenceType() ||
475  (!RetType->isBooleanType() && !RetType->isVoidType())) {
476  S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(),
477  diag::err_await_suspend_invalid_return_type)
478  << RetType;
479  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
480  << AwaitSuspend->getDirectCallee();
481  Calls.IsInvalid = true;
482  }
483  }
484  }
485 
486  return Calls;
487 }
488 
490  SourceLocation Loc, StringRef Name,
491  MultiExprArg Args) {
492 
493  // Form a reference to the promise.
494  ExprResult PromiseRef = S.BuildDeclRefExpr(
495  Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc);
496  if (PromiseRef.isInvalid())
497  return ExprError();
498 
499  return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
500 }
501 
503  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
504  auto *FD = cast<FunctionDecl>(CurContext);
505  bool IsThisDependentType = [&] {
506  if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
507  return MD->isInstance() && MD->getThisType()->isDependentType();
508  else
509  return false;
510  }();
511 
512  QualType T = FD->getType()->isDependentType() || IsThisDependentType
513  ? Context.DependentTy
514  : lookupPromiseType(*this, FD, Loc);
515  if (T.isNull())
516  return nullptr;
517 
518  auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(),
519  &PP.getIdentifierTable().get("__promise"), T,
520  Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
521  CheckVariableDeclarationType(VD);
522  if (VD->isInvalidDecl())
523  return nullptr;
524 
525  auto *ScopeInfo = getCurFunction();
526  // Build a list of arguments, based on the coroutine functions arguments,
527  // that will be passed to the promise type's constructor.
528  llvm::SmallVector<Expr *, 4> CtorArgExprs;
529 
530  // Add implicit object parameter.
531  if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
532  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
533  ExprResult ThisExpr = ActOnCXXThis(Loc);
534  if (ThisExpr.isInvalid())
535  return nullptr;
536  ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
537  if (ThisExpr.isInvalid())
538  return nullptr;
539  CtorArgExprs.push_back(ThisExpr.get());
540  }
541  }
542 
543  auto &Moves = ScopeInfo->CoroutineParameterMoves;
544  for (auto *PD : FD->parameters()) {
545  if (PD->getType()->isDependentType())
546  continue;
547 
548  auto RefExpr = ExprEmpty();
549  auto Move = Moves.find(PD);
550  assert(Move != Moves.end() &&
551  "Coroutine function parameter not inserted into move map");
552  // If a reference to the function parameter exists in the coroutine
553  // frame, use that reference.
554  auto *MoveDecl =
555  cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl());
556  RefExpr =
557  BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(),
558  ExprValueKind::VK_LValue, FD->getLocation());
559  if (RefExpr.isInvalid())
560  return nullptr;
561  CtorArgExprs.push_back(RefExpr.get());
562  }
563 
564  // Create an initialization sequence for the promise type using the
565  // constructor arguments, wrapped in a parenthesized list expression.
566  Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(),
567  CtorArgExprs, FD->getLocation());
570  VD->getLocation(), /*DirectInit=*/true, PLE);
571  InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs,
572  /*TopLevelOfInitList=*/false,
573  /*TreatUnavailableAsInvalid=*/false);
574 
575  // Attempt to initialize the promise type with the arguments.
576  // If that fails, fall back to the promise type's default constructor.
577  if (InitSeq) {
578  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs);
579  if (Result.isInvalid()) {
580  VD->setInvalidDecl();
581  } else if (Result.get()) {
582  VD->setInit(MaybeCreateExprWithCleanups(Result.get()));
583  VD->setInitStyle(VarDecl::CallInit);
584  CheckCompleteVariableDeclaration(VD);
585  }
586  } else
587  ActOnUninitializedDecl(VD);
588 
589  FD->addDecl(VD);
590  return VD;
591 }
592 
593 /// Check that this is a context in which a coroutine suspension can appear.
595  StringRef Keyword,
596  bool IsImplicit = false) {
597  if (!isValidCoroutineContext(S, Loc, Keyword))
598  return nullptr;
599 
600  assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope");
601 
602  auto *ScopeInfo = S.getCurFunction();
603  assert(ScopeInfo && "missing function scope for function");
604 
605  if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit)
606  ScopeInfo->setFirstCoroutineStmt(Loc, Keyword);
607 
608  if (ScopeInfo->CoroutinePromise)
609  return ScopeInfo;
610 
611  if (!S.buildCoroutineParameterMoves(Loc))
612  return nullptr;
613 
614  ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc);
615  if (!ScopeInfo->CoroutinePromise)
616  return nullptr;
617 
618  return ScopeInfo;
619 }
620 
622  StringRef Keyword) {
623  if (!checkCoroutineContext(*this, KWLoc, Keyword))
624  return false;
625  auto *ScopeInfo = getCurFunction();
626  assert(ScopeInfo->CoroutinePromise);
627 
628  // If we have existing coroutine statements then we have already built
629  // the initial and final suspend points.
630  if (!ScopeInfo->NeedsCoroutineSuspends)
631  return true;
632 
633  ScopeInfo->setNeedsCoroutineSuspends(false);
634 
635  auto *Fn = cast<FunctionDecl>(CurContext);
636  SourceLocation Loc = Fn->getLocation();
637  // Build the initial suspend point
638  auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
639  ExprResult Suspend =
640  buildPromiseCall(*this, ScopeInfo->CoroutinePromise, Loc, Name, None);
641  if (Suspend.isInvalid())
642  return StmtError();
643  Suspend = buildOperatorCoawaitCall(*this, SC, Loc, Suspend.get());
644  if (Suspend.isInvalid())
645  return StmtError();
646  Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),
647  /*IsImplicit*/ true);
648  Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
649  if (Suspend.isInvalid()) {
650  Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
651  << ((Name == "initial_suspend") ? 0 : 1);
652  Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
653  return StmtError();
654  }
655  return cast<Stmt>(Suspend.get());
656  };
657 
658  StmtResult InitSuspend = buildSuspends("initial_suspend");
659  if (InitSuspend.isInvalid())
660  return true;
661 
662  StmtResult FinalSuspend = buildSuspends("final_suspend");
663  if (FinalSuspend.isInvalid())
664  return true;
665 
666  ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());
667 
668  return true;
669 }
670 
672  if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) {
673  CorrectDelayedTyposInExpr(E);
674  return ExprError();
675  }
676 
677  if (E->getType()->isPlaceholderType()) {
678  ExprResult R = CheckPlaceholderExpr(E);
679  if (R.isInvalid()) return ExprError();
680  E = R.get();
681  }
682  ExprResult Lookup = buildOperatorCoawaitLookupExpr(*this, S, Loc);
683  if (Lookup.isInvalid())
684  return ExprError();
685  return BuildUnresolvedCoawaitExpr(Loc, E,
686  cast<UnresolvedLookupExpr>(Lookup.get()));
687 }
688 
690  UnresolvedLookupExpr *Lookup) {
691  auto *FSI = checkCoroutineContext(*this, Loc, "co_await");
692  if (!FSI)
693  return ExprError();
694 
695  if (E->getType()->isPlaceholderType()) {
696  ExprResult R = CheckPlaceholderExpr(E);
697  if (R.isInvalid())
698  return ExprError();
699  E = R.get();
700  }
701 
702  auto *Promise = FSI->CoroutinePromise;
703  if (Promise->getType()->isDependentType()) {
704  Expr *Res =
705  new (Context) DependentCoawaitExpr(Loc, Context.DependentTy, E, Lookup);
706  return Res;
707  }
708 
709  auto *RD = Promise->getType()->getAsCXXRecordDecl();
710  if (lookupMember(*this, "await_transform", RD, Loc)) {
711  ExprResult R = buildPromiseCall(*this, Promise, Loc, "await_transform", E);
712  if (R.isInvalid()) {
713  Diag(Loc,
714  diag::note_coroutine_promise_implicit_await_transform_required_here)
715  << E->getSourceRange();
716  return ExprError();
717  }
718  E = R.get();
719  }
720  ExprResult Awaitable = buildOperatorCoawaitCall(*this, Loc, E, Lookup);
721  if (Awaitable.isInvalid())
722  return ExprError();
723 
724  return BuildResolvedCoawaitExpr(Loc, Awaitable.get());
725 }
726 
728  bool IsImplicit) {
729  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit);
730  if (!Coroutine)
731  return ExprError();
732 
733  if (E->getType()->isPlaceholderType()) {
734  ExprResult R = CheckPlaceholderExpr(E);
735  if (R.isInvalid()) return ExprError();
736  E = R.get();
737  }
738 
739  if (E->getType()->isDependentType()) {
740  Expr *Res = new (Context)
741  CoawaitExpr(Loc, Context.DependentTy, E, IsImplicit);
742  return Res;
743  }
744 
745  // If the expression is a temporary, materialize it as an lvalue so that we
746  // can use it multiple times.
747  if (E->getValueKind() == VK_RValue)
748  E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
749 
750  // The location of the `co_await` token cannot be used when constructing
751  // the member call expressions since it's before the location of `Expr`, which
752  // is used as the start of the member call expression.
753  SourceLocation CallLoc = E->getExprLoc();
754 
755  // Build the await_ready, await_suspend, await_resume calls.
757  buildCoawaitCalls(*this, Coroutine->CoroutinePromise, CallLoc, E);
758  if (RSS.IsInvalid)
759  return ExprError();
760 
761  Expr *Res =
762  new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
763  RSS.Results[2], RSS.OpaqueValue, IsImplicit);
764 
765  return Res;
766 }
767 
769  if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) {
770  CorrectDelayedTyposInExpr(E);
771  return ExprError();
772  }
773 
774  // Build yield_value call.
775  ExprResult Awaitable = buildPromiseCall(
776  *this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E);
777  if (Awaitable.isInvalid())
778  return ExprError();
779 
780  // Build 'operator co_await' call.
781  Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get());
782  if (Awaitable.isInvalid())
783  return ExprError();
784 
785  return BuildCoyieldExpr(Loc, Awaitable.get());
786 }
788  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
789  if (!Coroutine)
790  return ExprError();
791 
792  if (E->getType()->isPlaceholderType()) {
793  ExprResult R = CheckPlaceholderExpr(E);
794  if (R.isInvalid()) return ExprError();
795  E = R.get();
796  }
797 
798  if (E->getType()->isDependentType()) {
799  Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, E);
800  return Res;
801  }
802 
803  // If the expression is a temporary, materialize it as an lvalue so that we
804  // can use it multiple times.
805  if (E->getValueKind() == VK_RValue)
806  E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
807 
808  // Build the await_ready, await_suspend, await_resume calls.
810  buildCoawaitCalls(*this, Coroutine->CoroutinePromise, Loc, E);
811  if (RSS.IsInvalid)
812  return ExprError();
813 
814  Expr *Res =
815  new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
816  RSS.Results[2], RSS.OpaqueValue);
817 
818  return Res;
819 }
820 
822  if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) {
823  CorrectDelayedTyposInExpr(E);
824  return StmtError();
825  }
826  return BuildCoreturnStmt(Loc, E);
827 }
828 
830  bool IsImplicit) {
831  auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit);
832  if (!FSI)
833  return StmtError();
834 
835  if (E && E->getType()->isPlaceholderType() &&
836  !E->getType()->isSpecificPlaceholderType(BuiltinType::Overload)) {
837  ExprResult R = CheckPlaceholderExpr(E);
838  if (R.isInvalid()) return StmtError();
839  E = R.get();
840  }
841 
842  // Move the return value if we can
843  if (E) {
844  auto NRVOCandidate = this->getCopyElisionCandidate(E->getType(), E, CES_AsIfByStdMove);
845  if (NRVOCandidate) {
846  InitializedEntity Entity =
847  InitializedEntity::InitializeResult(Loc, E->getType(), NRVOCandidate);
848  ExprResult MoveResult = this->PerformMoveOrCopyInitialization(
849  Entity, NRVOCandidate, E->getType(), E);
850  if (MoveResult.get())
851  E = MoveResult.get();
852  }
853  }
854 
855  // FIXME: If the operand is a reference to a variable that's about to go out
856  // of scope, we should treat the operand as an xvalue for this overload
857  // resolution.
858  VarDecl *Promise = FSI->CoroutinePromise;
859  ExprResult PC;
860  if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
861  PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
862  } else {
863  E = MakeFullDiscardedValueExpr(E).get();
864  PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
865  }
866  if (PC.isInvalid())
867  return StmtError();
868 
869  Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
870 
871  Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
872  return Res;
873 }
874 
875 /// Look up the std::nothrow object.
878  assert(Std && "Should already be diagnosed");
879 
880  LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
882  if (!S.LookupQualifiedName(Result, Std)) {
883  // FIXME: <experimental/coroutine> should have been included already.
884  // If we require it to include <new> then this diagnostic is no longer
885  // needed.
886  S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
887  return nullptr;
888  }
889 
890  auto *VD = Result.getAsSingle<VarDecl>();
891  if (!VD) {
892  Result.suppressDiagnostics();
893  // We found something weird. Complain about the first thing we found.
894  NamedDecl *Found = *Result.begin();
895  S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
896  return nullptr;
897  }
898 
899  ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
900  if (DR.isInvalid())
901  return nullptr;
902 
903  return DR.get();
904 }
905 
906 // Find an appropriate delete for the promise.
908  QualType PromiseType) {
909  FunctionDecl *OperatorDelete = nullptr;
910 
911  DeclarationName DeleteName =
913 
914  auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
915  assert(PointeeRD && "PromiseType must be a CxxRecordDecl type");
916 
917  if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete))
918  return nullptr;
919 
920  if (!OperatorDelete) {
921  // Look for a global declaration.
922  const bool CanProvideSize = S.isCompleteType(Loc, PromiseType);
923  const bool Overaligned = false;
924  OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
925  Overaligned, DeleteName);
926  }
927  S.MarkFunctionReferenced(Loc, OperatorDelete);
928  return OperatorDelete;
929 }
930 
931 
933  FunctionScopeInfo *Fn = getCurFunction();
934  assert(Fn && Fn->isCoroutine() && "not a coroutine");
935  if (!Body) {
936  assert(FD->isInvalidDecl() &&
937  "a null body is only allowed for invalid declarations");
938  return;
939  }
940  // We have a function that uses coroutine keywords, but we failed to build
941  // the promise type.
942  if (!Fn->CoroutinePromise)
943  return FD->setInvalidDecl();
944 
945  if (isa<CoroutineBodyStmt>(Body)) {
946  // Nothing todo. the body is already a transformed coroutine body statement.
947  return;
948  }
949 
950  // Coroutines [stmt.return]p1:
951  // A return statement shall not appear in a coroutine.
952  if (Fn->FirstReturnLoc.isValid()) {
953  assert(Fn->FirstCoroutineStmtLoc.isValid() &&
954  "first coroutine location not set");
955  Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
956  Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
958  }
959  CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body);
960  if (Builder.isInvalid() || !Builder.buildStatements())
961  return FD->setInvalidDecl();
962 
963  // Build body for the coroutine wrapper statement.
964  Body = CoroutineBodyStmt::Create(Context, Builder);
965 }
966 
969  Stmt *Body)
970  : S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()),
971  IsPromiseDependentType(
972  !Fn.CoroutinePromise ||
973  Fn.CoroutinePromise->getType()->isDependentType()) {
974  this->Body = Body;
975 
976  for (auto KV : Fn.CoroutineParameterMoves)
977  this->ParamMovesVector.push_back(KV.second);
978  this->ParamMoves = this->ParamMovesVector;
979 
980  if (!IsPromiseDependentType) {
981  PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl();
982  assert(PromiseRecordDecl && "Type should have already been checked");
983  }
984  this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend();
985 }
986 
988  assert(this->IsValid && "coroutine already invalid");
989  this->IsValid = makeReturnObject();
990  if (this->IsValid && !IsPromiseDependentType)
992  return this->IsValid;
993 }
994 
996  assert(this->IsValid && "coroutine already invalid");
997  assert(!this->IsPromiseDependentType &&
998  "coroutine cannot have a dependent promise type");
999  this->IsValid = makeOnException() && makeOnFallthrough() &&
1000  makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
1001  makeNewAndDeleteExpr();
1002  return this->IsValid;
1003 }
1004 
1005 bool CoroutineStmtBuilder::makePromiseStmt() {
1006  // Form a declaration statement for the promise declaration, so that AST
1007  // visitors can more easily find it.
1008  StmtResult PromiseStmt =
1010  if (PromiseStmt.isInvalid())
1011  return false;
1012 
1013  this->Promise = PromiseStmt.get();
1014  return true;
1015 }
1016 
1017 bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() {
1018  if (Fn.hasInvalidCoroutineSuspends())
1019  return false;
1020  this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first);
1021  this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second);
1022  return true;
1023 }
1024 
1026  CXXRecordDecl *PromiseRecordDecl,
1027  FunctionScopeInfo &Fn) {
1028  auto Loc = E->getExprLoc();
1029  if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) {
1030  auto *Decl = DeclRef->getDecl();
1031  if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) {
1032  if (Method->isStatic())
1033  return true;
1034  else
1035  Loc = Decl->getLocation();
1036  }
1037  }
1038 
1039  S.Diag(
1040  Loc,
1041  diag::err_coroutine_promise_get_return_object_on_allocation_failure)
1042  << PromiseRecordDecl;
1043  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1045  return false;
1046 }
1047 
1048 bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
1049  assert(!IsPromiseDependentType &&
1050  "cannot make statement while the promise type is dependent");
1051 
1052  // [dcl.fct.def.coroutine]/8
1053  // The unqualified-id get_return_object_on_allocation_failure is looked up in
1054  // the scope of class P by class member access lookup (3.4.5). ...
1055  // If an allocation function returns nullptr, ... the coroutine return value
1056  // is obtained by a call to ... get_return_object_on_allocation_failure().
1057 
1058  DeclarationName DN =
1059  S.PP.getIdentifierInfo("get_return_object_on_allocation_failure");
1060  LookupResult Found(S, DN, Loc, Sema::LookupMemberName);
1061  if (!S.LookupQualifiedName(Found, PromiseRecordDecl))
1062  return true;
1063 
1064  CXXScopeSpec SS;
1065  ExprResult DeclNameExpr =
1066  S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
1067  if (DeclNameExpr.isInvalid())
1068  return false;
1069 
1070  if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn))
1071  return false;
1072 
1073  ExprResult ReturnObjectOnAllocationFailure =
1074  S.ActOnCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc);
1075  if (ReturnObjectOnAllocationFailure.isInvalid())
1076  return false;
1077 
1079  S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
1080  if (ReturnStmt.isInvalid()) {
1081  S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here)
1082  << DN;
1083  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1085  return false;
1086  }
1087 
1088  this->ReturnStmtOnAllocFailure = ReturnStmt.get();
1089  return true;
1090 }
1091 
1092 bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
1093  // Form and check allocation and deallocation calls.
1094  assert(!IsPromiseDependentType &&
1095  "cannot make statement while the promise type is dependent");
1096  QualType PromiseType = Fn.CoroutinePromise->getType();
1097 
1098  if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
1099  return false;
1100 
1101  const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
1102 
1103  // [dcl.fct.def.coroutine]/7
1104  // Lookup allocation functions using a parameter list composed of the
1105  // requested size of the coroutine state being allocated, followed by
1106  // the coroutine function's arguments. If a matching allocation function
1107  // exists, use it. Otherwise, use an allocation function that just takes
1108  // the requested size.
1109 
1110  FunctionDecl *OperatorNew = nullptr;
1111  FunctionDecl *OperatorDelete = nullptr;
1112  FunctionDecl *UnusedResult = nullptr;
1113  bool PassAlignment = false;
1114  SmallVector<Expr *, 1> PlacementArgs;
1115 
1116  // [dcl.fct.def.coroutine]/7
1117  // "The allocation function’s name is looked up in the scope of P.
1118  // [...] If the lookup finds an allocation function in the scope of P,
1119  // overload resolution is performed on a function call created by assembling
1120  // an argument list. The first argument is the amount of space requested,
1121  // and has type std::size_t. The lvalues p1 ... pn are the succeeding
1122  // arguments."
1123  //
1124  // ...where "p1 ... pn" are defined earlier as:
1125  //
1126  // [dcl.fct.def.coroutine]/3
1127  // "For a coroutine f that is a non-static member function, let P1 denote the
1128  // type of the implicit object parameter (13.3.1) and P2 ... Pn be the types
1129  // of the function parameters; otherwise let P1 ... Pn be the types of the
1130  // function parameters. Let p1 ... pn be lvalues denoting those objects."
1131  if (auto *MD = dyn_cast<CXXMethodDecl>(&FD)) {
1132  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
1133  ExprResult ThisExpr = S.ActOnCXXThis(Loc);
1134  if (ThisExpr.isInvalid())
1135  return false;
1136  ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
1137  if (ThisExpr.isInvalid())
1138  return false;
1139  PlacementArgs.push_back(ThisExpr.get());
1140  }
1141  }
1142  for (auto *PD : FD.parameters()) {
1143  if (PD->getType()->isDependentType())
1144  continue;
1145 
1146  // Build a reference to the parameter.
1147  auto PDLoc = PD->getLocation();
1148  ExprResult PDRefExpr =
1149  S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(),
1150  ExprValueKind::VK_LValue, PDLoc);
1151  if (PDRefExpr.isInvalid())
1152  return false;
1153 
1154  PlacementArgs.push_back(PDRefExpr.get());
1155  }
1156  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1157  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1158  /*isArray*/ false, PassAlignment, PlacementArgs,
1159  OperatorNew, UnusedResult, /*Diagnose*/ false);
1160 
1161  // [dcl.fct.def.coroutine]/7
1162  // "If no matching function is found, overload resolution is performed again
1163  // on a function call created by passing just the amount of space required as
1164  // an argument of type std::size_t."
1165  if (!OperatorNew && !PlacementArgs.empty()) {
1166  PlacementArgs.clear();
1167  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1168  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1169  /*isArray*/ false, PassAlignment, PlacementArgs,
1170  OperatorNew, UnusedResult, /*Diagnose*/ false);
1171  }
1172 
1173  // [dcl.fct.def.coroutine]/7
1174  // "The allocation function’s name is looked up in the scope of P. If this
1175  // lookup fails, the allocation function’s name is looked up in the global
1176  // scope."
1177  if (!OperatorNew) {
1178  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Global,
1179  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1180  /*isArray*/ false, PassAlignment, PlacementArgs,
1181  OperatorNew, UnusedResult);
1182  }
1183 
1184  bool IsGlobalOverload =
1185  OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
1186  // If we didn't find a class-local new declaration and non-throwing new
1187  // was is required then we need to lookup the non-throwing global operator
1188  // instead.
1189  if (RequiresNoThrowAlloc && (!OperatorNew || IsGlobalOverload)) {
1190  auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
1191  if (!StdNoThrow)
1192  return false;
1193  PlacementArgs = {StdNoThrow};
1194  OperatorNew = nullptr;
1195  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Both,
1196  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1197  /*isArray*/ false, PassAlignment, PlacementArgs,
1198  OperatorNew, UnusedResult);
1199  }
1200 
1201  if (!OperatorNew)
1202  return false;
1203 
1204  if (RequiresNoThrowAlloc) {
1205  const auto *FT = OperatorNew->getType()->getAs<FunctionProtoType>();
1206  if (!FT->isNothrow(/*ResultIfDependent*/ false)) {
1207  S.Diag(OperatorNew->getLocation(),
1208  diag::err_coroutine_promise_new_requires_nothrow)
1209  << OperatorNew;
1210  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
1211  << OperatorNew;
1212  return false;
1213  }
1214  }
1215 
1216  if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr)
1217  return false;
1218 
1219  Expr *FramePtr =
1220  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
1221 
1222  Expr *FrameSize =
1223  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_size, {});
1224 
1225  // Make new call.
1226 
1227  ExprResult NewRef =
1228  S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
1229  if (NewRef.isInvalid())
1230  return false;
1231 
1232  SmallVector<Expr *, 2> NewArgs(1, FrameSize);
1233  for (auto Arg : PlacementArgs)
1234  NewArgs.push_back(Arg);
1235 
1236  ExprResult NewExpr =
1237  S.ActOnCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
1238  NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
1239  if (NewExpr.isInvalid())
1240  return false;
1241 
1242  // Make delete call.
1243 
1244  QualType OpDeleteQualType = OperatorDelete->getType();
1245 
1246  ExprResult DeleteRef =
1247  S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
1248  if (DeleteRef.isInvalid())
1249  return false;
1250 
1251  Expr *CoroFree =
1252  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_free, {FramePtr});
1253 
1254  SmallVector<Expr *, 2> DeleteArgs{CoroFree};
1255 
1256  // Check if we need to pass the size.
1257  const auto *OpDeleteType =
1258  OpDeleteQualType.getTypePtr()->getAs<FunctionProtoType>();
1259  if (OpDeleteType->getNumParams() > 1)
1260  DeleteArgs.push_back(FrameSize);
1261 
1262  ExprResult DeleteExpr =
1263  S.ActOnCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
1264  DeleteExpr =
1265  S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
1266  if (DeleteExpr.isInvalid())
1267  return false;
1268 
1269  this->Allocate = NewExpr.get();
1270  this->Deallocate = DeleteExpr.get();
1271 
1272  return true;
1273 }
1274 
1275 bool CoroutineStmtBuilder::makeOnFallthrough() {
1276  assert(!IsPromiseDependentType &&
1277  "cannot make statement while the promise type is dependent");
1278 
1279  // [dcl.fct.def.coroutine]/4
1280  // The unqualified-ids 'return_void' and 'return_value' are looked up in
1281  // the scope of class P. If both are found, the program is ill-formed.
1282  bool HasRVoid, HasRValue;
1283  LookupResult LRVoid =
1284  lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid);
1285  LookupResult LRValue =
1286  lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue);
1287 
1288  StmtResult Fallthrough;
1289  if (HasRVoid && HasRValue) {
1290  // FIXME Improve this diagnostic
1291  S.Diag(FD.getLocation(),
1292  diag::err_coroutine_promise_incompatible_return_functions)
1293  << PromiseRecordDecl;
1294  S.Diag(LRVoid.getRepresentativeDecl()->getLocation(),
1295  diag::note_member_first_declared_here)
1296  << LRVoid.getLookupName();
1297  S.Diag(LRValue.getRepresentativeDecl()->getLocation(),
1298  diag::note_member_first_declared_here)
1299  << LRValue.getLookupName();
1300  return false;
1301  } else if (!HasRVoid && !HasRValue) {
1302  // FIXME: The PDTS currently specifies this case as UB, not ill-formed.
1303  // However we still diagnose this as an error since until the PDTS is fixed.
1304  S.Diag(FD.getLocation(),
1305  diag::err_coroutine_promise_requires_return_function)
1306  << PromiseRecordDecl;
1307  S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1308  << PromiseRecordDecl;
1309  return false;
1310  } else if (HasRVoid) {
1311  // If the unqualified-id return_void is found, flowing off the end of a
1312  // coroutine is equivalent to a co_return with no operand. Otherwise,
1313  // flowing off the end of a coroutine results in undefined behavior.
1314  Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr,
1315  /*IsImplicit*/false);
1316  Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get());
1317  if (Fallthrough.isInvalid())
1318  return false;
1319  }
1320 
1321  this->OnFallthrough = Fallthrough.get();
1322  return true;
1323 }
1324 
1325 bool CoroutineStmtBuilder::makeOnException() {
1326  // Try to form 'p.unhandled_exception();'
1327  assert(!IsPromiseDependentType &&
1328  "cannot make statement while the promise type is dependent");
1329 
1330  const bool RequireUnhandledException = S.getLangOpts().CXXExceptions;
1331 
1332  if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) {
1333  auto DiagID =
1334  RequireUnhandledException
1335  ? diag::err_coroutine_promise_unhandled_exception_required
1336  : diag::
1337  warn_coroutine_promise_unhandled_exception_required_with_exceptions;
1338  S.Diag(Loc, DiagID) << PromiseRecordDecl;
1339  S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1340  << PromiseRecordDecl;
1341  return !RequireUnhandledException;
1342  }
1343 
1344  // If exceptions are disabled, don't try to build OnException.
1345  if (!S.getLangOpts().CXXExceptions)
1346  return true;
1347 
1348  ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
1349  "unhandled_exception", None);
1350  UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
1351  /*DiscardedValue*/ false);
1352  if (UnhandledException.isInvalid())
1353  return false;
1354 
1355  // Since the body of the coroutine will be wrapped in try-catch, it will
1356  // be incompatible with SEH __try if present in a function.
1357  if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) {
1358  S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions);
1359  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1361  return false;
1362  }
1363 
1364  this->OnException = UnhandledException.get();
1365  return true;
1366 }
1367 
1368 bool CoroutineStmtBuilder::makeReturnObject() {
1369  // Build implicit 'p.get_return_object()' expression and form initialization
1370  // of return type from it.
1371  ExprResult ReturnObject =
1372  buildPromiseCall(S, Fn.CoroutinePromise, Loc, "get_return_object", None);
1373  if (ReturnObject.isInvalid())
1374  return false;
1375 
1376  this->ReturnValue = ReturnObject.get();
1377  return true;
1378 }
1379 
1381  if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
1382  auto *MethodDecl = MbrRef->getMethodDecl();
1383  S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here)
1384  << MethodDecl;
1385  }
1386  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1388 }
1389 
1390 bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
1391  assert(!IsPromiseDependentType &&
1392  "cannot make statement while the promise type is dependent");
1393  assert(this->ReturnValue && "ReturnValue must be already formed");
1394 
1395  QualType const GroType = this->ReturnValue->getType();
1396  assert(!GroType->isDependentType() &&
1397  "get_return_object type must no longer be dependent");
1398 
1399  QualType const FnRetType = FD.getReturnType();
1400  assert(!FnRetType->isDependentType() &&
1401  "get_return_object type must no longer be dependent");
1402 
1403  if (FnRetType->isVoidType()) {
1404  ExprResult Res =
1405  S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
1406  if (Res.isInvalid())
1407  return false;
1408 
1409  this->ResultDecl = Res.get();
1410  return true;
1411  }
1412 
1413  if (GroType->isVoidType()) {
1414  // Trigger a nice error message.
1415  InitializedEntity Entity =
1416  InitializedEntity::InitializeResult(Loc, FnRetType, false);
1417  S.PerformMoveOrCopyInitialization(Entity, nullptr, FnRetType, ReturnValue);
1419  return false;
1420  }
1421 
1422  auto *GroDecl = VarDecl::Create(
1423  S.Context, &FD, FD.getLocation(), FD.getLocation(),
1424  &S.PP.getIdentifierTable().get("__coro_gro"), GroType,
1425  S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
1426 
1427  S.CheckVariableDeclarationType(GroDecl);
1428  if (GroDecl->isInvalidDecl())
1429  return false;
1430 
1432  ExprResult Res = S.PerformMoveOrCopyInitialization(Entity, nullptr, GroType,
1433  this->ReturnValue);
1434  if (Res.isInvalid())
1435  return false;
1436 
1437  Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
1438  if (Res.isInvalid())
1439  return false;
1440 
1441  S.AddInitializerToDecl(GroDecl, Res.get(),
1442  /*DirectInit=*/false);
1443 
1444  S.FinalizeDeclaration(GroDecl);
1445 
1446  // Form a declaration statement for the return declaration, so that AST
1447  // visitors can more easily find it.
1448  StmtResult GroDeclStmt =
1449  S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
1450  if (GroDeclStmt.isInvalid())
1451  return false;
1452 
1453  this->ResultDecl = GroDeclStmt.get();
1454 
1455  ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
1456  if (declRef.isInvalid())
1457  return false;
1458 
1459  StmtResult ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
1460  if (ReturnStmt.isInvalid()) {
1462  return false;
1463  }
1464  if (cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl)
1465  GroDecl->setNRVOVariable(true);
1466 
1467  this->ReturnStmt = ReturnStmt.get();
1468  return true;
1469 }
1470 
1471 // Create a static_cast<T&&>(expr).
1472 static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) {
1473  if (T.isNull())
1474  T = E->getType();
1475  QualType TargetType = S.BuildReferenceType(
1476  T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName());
1477  SourceLocation ExprLoc = E->getBeginLoc();
1478  TypeSourceInfo *TargetLoc =
1479  S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc);
1480 
1481  return S
1482  .BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
1483  SourceRange(ExprLoc, ExprLoc), E->getSourceRange())
1484  .get();
1485 }
1486 
1487 /// Build a variable declaration for move parameter.
1489  IdentifierInfo *II) {
1490  TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc);
1491  VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type,
1492  TInfo, SC_None);
1493  Decl->setImplicit();
1494  return Decl;
1495 }
1496 
1497 // Build statements that move coroutine function parameters to the coroutine
1498 // frame, and store them on the function scope info.
1500  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
1501  auto *FD = cast<FunctionDecl>(CurContext);
1502 
1503  auto *ScopeInfo = getCurFunction();
1504  assert(ScopeInfo->CoroutineParameterMoves.empty() &&
1505  "Should not build parameter moves twice");
1506 
1507  for (auto *PD : FD->parameters()) {
1508  if (PD->getType()->isDependentType())
1509  continue;
1510 
1511  ExprResult PDRefExpr =
1512  BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(),
1513  ExprValueKind::VK_LValue, Loc); // FIXME: scope?
1514  if (PDRefExpr.isInvalid())
1515  return false;
1516 
1517  Expr *CExpr = nullptr;
1518  if (PD->getType()->getAsCXXRecordDecl() ||
1519  PD->getType()->isRValueReferenceType())
1520  CExpr = castForMoving(*this, PDRefExpr.get());
1521  else
1522  CExpr = PDRefExpr.get();
1523 
1524  auto D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier());
1525  AddInitializerToDecl(D, CExpr, /*DirectInit=*/true);
1526 
1527  // Convert decl to a statement.
1528  StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc);
1529  if (Stmt.isInvalid())
1530  return false;
1531 
1532  ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get()));
1533  }
1534  return true;
1535 }
1536 
1538  CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args);
1539  if (!Res)
1540  return StmtError();
1541  return Res;
1542 }
1543 
1545  SourceLocation FuncLoc) {
1546  if (!StdCoroutineTraitsCache) {
1547  if (auto StdExp = lookupStdExperimentalNamespace()) {
1548  LookupResult Result(*this,
1549  &PP.getIdentifierTable().get("coroutine_traits"),
1550  FuncLoc, LookupOrdinaryName);
1551  if (!LookupQualifiedName(Result, StdExp)) {
1552  Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
1553  << "std::experimental::coroutine_traits";
1554  return nullptr;
1555  }
1556  if (!(StdCoroutineTraitsCache =
1557  Result.getAsSingle<ClassTemplateDecl>())) {
1558  Result.suppressDiagnostics();
1559  NamedDecl *Found = *Result.begin();
1560  Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits);
1561  return nullptr;
1562  }
1563  }
1564  }
1565  return StdCoroutineTraitsCache;
1566 }
NamespaceDecl * lookupStdExperimentalNamespace()
static Expr * buildStdNoThrowDeclRef(Sema &S, SourceLocation Loc)
Look up the std::nothrow object.
static ExprResult buildMemberCall(Sema &S, Expr *Base, SourceLocation Loc, StringRef Name, MultiExprArg Args)
void setImplicit(bool I=true)
Definition: DeclBase.h:550
Represents a function declaration or definition.
Definition: Decl.h:1737
Represents a &#39;co_await&#39; expression while the type of the promise is dependent.
Definition: ExprCXX.h:4454
bool FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, DeclarationName Name, FunctionDecl *&Operator, bool Diagnose=true)
NamespaceDecl * getStdNamespace() const
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
ExprResult PerformContextuallyConvertToBool(Expr *From)
PerformContextuallyConvertToBool - Perform a contextual conversion of the expression From to bool (C+...
RefQualifierKind getRefQualifier() const
Retrieve the ref-qualifier associated with this function type.
Definition: Type.h:4028
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2542
A (possibly-)qualified type.
Definition: Type.h:634
static Expr * maybeTailCall(Sema &S, QualType RetType, Expr *E, SourceLocation Loc)
static VarDecl * buildVarDecl(Sema &S, SourceLocation Loc, QualType Type, IdentifierInfo *II)
Build a variable declaration for move parameter.
IdentifierInfo * getIdentifierInfo(StringRef Name) const
Return information about the specified preprocessor identifier token.
Ordinary name lookup, which finds ordinary names (functions, variables, typedefs, etc...
Definition: Sema.h:3118
bool LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation=false)
Perform unqualified name lookup starting from a given scope.
static Expr * castForMoving(Sema &S, Expr *E, QualType T=QualType())
Represents a &#39;co_return&#39; statement in the C++ Coroutines TS.
Definition: StmtCXX.h:434
Stmt - This represents one statement.
Definition: Stmt.h:65
bool isSpecificPlaceholderType(unsigned K) const
Test for a specific placeholder type.
Definition: Type.h:6540
QualType getLValueReferenceType(QualType T, bool SpelledAsLValue=true) const
Return the uniqued reference to the type for an lvalue reference to the specified type...
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
Emit a diagnostic.
Definition: Sema.h:1342
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
A reference to a name which we were able to look up during parsing but could not resolve to a specifi...
Definition: ExprCXX.h:2827
Scope * TUScope
Translation Unit Scope - useful to Objective-C actions that need to lookup file scope declarations in...
Definition: Sema.h:862
QualType getNonReferenceType() const
If Type is a reference type (e.g., const int&), returns the type that the reference refers to ("const...
Definition: Type.h:6250
The base class of the type hierarchy.
Definition: Type.h:1409
OpaqueValueExpr * OpaqueValue
StringRef getFirstCoroutineStmtKeyword() const
Definition: ScopeInfo.h:457
Represent a C++ namespace.
Definition: Decl.h:514
A container of type source information.
Definition: Decl.h:86
void MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func, bool MightBeOdrUse=true)
Mark a function referenced, and check whether it is odr-used (C++ [basic.def.odr]p2, C99 6.9p3)
Definition: SemaExpr.cpp:14712
std::pair< Stmt *, Stmt * > CoroutineSuspends
The initial and final coroutine suspend points.
Definition: ScopeInfo.h:199
Retains information about a function, method, or block that is currently being parsed.
Definition: ScopeInfo.h:96
This file provides some common utility functions for processing Lambda related AST Constructs...
Represents a variable declaration or definition.
Definition: Decl.h:812
ActionResult< Stmt * > StmtResult
Definition: Ownership.h:264
bool isStructureType() const
Definition: Type.cpp:443
static NestedNameSpecifier * Create(const ASTContext &Context, NestedNameSpecifier *Prefix, IdentifierInfo *II)
Builds a specifier combining a prefix and an identifier.
DeclarationName getLookupName() const
Gets the name to look up.
Definition: Lookup.h:243
QualType getReturnType() const
Definition: Decl.h:2301
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6761
DeclContext * computeDeclContext(QualType T)
Compute the DeclContext that is associated with the given type.
StmtResult BuildCoreturnStmt(SourceLocation KwLoc, Expr *E, bool IsImplicit=false)
ExprResult ActOnFinishFullExpr(Expr *Expr, bool DiscardedValue)
Definition: Sema.h:5416
bool isAmbiguous() const
Definition: Lookup.h:301
bool isInvalidDecl() const
Definition: DeclBase.h:544
static InitializedEntity InitializeResult(SourceLocation ReturnLoc, QualType Type, bool NRVO)
Create the initialization entity for the result of a function.
static bool diagReturnOnAllocFailure(Sema &S, Expr *E, CXXRecordDecl *PromiseRecordDecl, FunctionScopeInfo &Fn)
Defines the clang::Expr interface and subclasses for C++ expressions.
ExprResult ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc, MultiExprArg ArgExprs, SourceLocation RParenLoc, Expr *ExecConfig=nullptr, bool IsExecConfig=false)
ActOnCallExpr - Handle a call to Fn with the specified array of arguments.
Definition: SemaExpr.cpp:5524
llvm::SmallMapVector< ParmVarDecl *, Stmt *, 4 > CoroutineParameterMoves
A mapping between the coroutine function parameters that were moved to the coroutine frame...
Definition: ScopeInfo.h:196
bool FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, AllocationFunctionScope NewScope, AllocationFunctionScope DeleteScope, QualType AllocType, bool IsArray, bool &PassAlignment, MultiExprArg PlaceArgs, FunctionDecl *&OperatorNew, FunctionDecl *&OperatorDelete, bool Diagnose=true)
Finds the overloads of operator new and delete that are appropriate for the allocation.
One of these records is kept for each identifier that is lexed.
static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise, SourceLocation Loc, Expr *E)
Build calls to await_ready, await_suspend, and await_resume for a co_await expression.
A C++ nested-name-specifier augmented with source location information.
ExprResult ExprEmpty()
Definition: Ownership.h:285
static InitializationKind CreateForInit(SourceLocation Loc, bool DirectInit, Expr *Init)
Create an initialization from an initializer (which, for direct initialization from a parenthesized l...
ArrayRef< QualType > getParamTypes() const
Definition: Type.h:3900
bool ActOnCoroutineBodyStart(Scope *S, SourceLocation KwLoc, StringRef Keyword)
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:263
DeclGroupPtrTy ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType=nullptr)
Definition: SemaDecl.cpp:53
static FunctionDecl * findDeleteForPromise(Sema &S, SourceLocation Loc, QualType PromiseType)
bool isReferenceType() const
Definition: Type.h:6313
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Decl.h:738
IdentifierTable & Idents
Definition: ASTContext.h:565
SourceLocation FirstSEHTryLoc
First SEH &#39;__try&#39; statement in the current function.
Definition: ScopeInfo.h:173
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:109
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2261
static ParenListExpr * Create(const ASTContext &Ctx, SourceLocation LParenLoc, ArrayRef< Expr *> Exprs, SourceLocation RParenLoc)
Create a paren list.
Definition: Expr.cpp:4115
bool isCompleteType(SourceLocation Loc, QualType T)
Definition: Sema.h:1692
Represents the results of name lookup.
Definition: Lookup.h:46
PtrTy get() const
Definition: Ownership.h:170
ExprResult CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc, const UnresolvedSetImpl &Fns, Expr *input, bool RequiresADL=true)
Create a unary operation that may resolve to an overloaded operator.
static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, SourceLocation Loc, Expr *E, UnresolvedLookupExpr *Lookup)
Build a call to &#39;operator co_await&#39; if there is a suitable operator for the given expression...
A convenient class for passing around template argument information.
Definition: TemplateBase.h:554
ExprValueKind getValueKind() const
getValueKind - The value kind that this expression produces.
Definition: Expr.h:407
StmtResult StmtError()
Definition: Ownership.h:280
Represents a declaration of a type.
Definition: Decl.h:2873
static ExprResult buildPromiseCall(Sema &S, VarDecl *Promise, SourceLocation Loc, StringRef Name, MultiExprArg Args)
static QualType lookupPromiseType(Sema &S, const FunctionDecl *FD, SourceLocation KwLoc)
Look up the std::coroutine_traits<...>::promise_type for the given function type. ...
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:40
const Type * getTypePtr() const
Retrieves a pointer to the underlying (unqualified) type.
Definition: Type.h:6077
ExprResult ActOnCXXThis(SourceLocation loc)
void append(iterator I, iterator E)
Represents a C++ nested-name-specifier or a global scope specifier.
Definition: DeclSpec.h:62
void CheckVariableDeclarationType(VarDecl *NewVD)
Definition: SemaDecl.cpp:7296
Preprocessor & PP
Definition: Sema.h:357
static VarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S)
Definition: Decl.cpp:1917
const LangOptions & getLangOpts() const
Definition: Sema.h:1265
bool isLambdaCallOperator(const CXXMethodDecl *MD)
Definition: ASTLambda.h:27
bool isUnevaluatedContext() const
Determines whether we are currently in a context that is not evaluated as per C++ [expr] p5...
Definition: Sema.h:7628
ExprResult BuildMemberReferenceExpr(Expr *Base, QualType BaseType, SourceLocation OpLoc, bool IsArrow, CXXScopeSpec &SS, SourceLocation TemplateKWLoc, NamedDecl *FirstQualifierInScope, const DeclarationNameInfo &NameInfo, const TemplateArgumentListInfo *TemplateArgs, const Scope *S, ActOnMemberAccessExtraArgs *ExtraArgs=nullptr)
Member name lookup, which finds the names of class/struct/union members.
Definition: Sema.h:3126
ExprResult BuildDeclarationNameExpr(const CXXScopeSpec &SS, LookupResult &R, bool NeedsADL, bool AcceptInvalidDecl=false)
Definition: SemaExpr.cpp:2885
static UnresolvedLookupExpr * Create(const ASTContext &Context, CXXRecordDecl *NamingClass, NestedNameSpecifierLoc QualifierLoc, const DeclarationNameInfo &NameInfo, bool RequiresADL, bool Overloaded, UnresolvedSetIterator Begin, UnresolvedSetIterator End)
Definition: ExprCXX.cpp:324
QualType CheckTemplateIdType(TemplateName Template, SourceLocation TemplateLoc, TemplateArgumentListInfo &TemplateArgs)
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:312
StmtResult ActOnDeclStmt(DeclGroupPtrTy Decl, SourceLocation StartLoc, SourceLocation EndLoc)
Definition: SemaStmt.cpp:71
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1634
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3692
StmtResult BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp)
Definition: SemaStmt.cpp:3515
StmtResult ActOnCoreturnStmt(Scope *S, SourceLocation KwLoc, Expr *E)
DeclarationNameTable DeclarationNames
Definition: ASTContext.h:568
const char * getName(unsigned ID) const
Return the identifier name for the specified builtin, e.g.
Definition: Builtins.h:85
bool buildCoroutineParameterMoves(SourceLocation Loc)
TypeSourceInfo * getTrivialTypeSourceInfo(QualType T, SourceLocation Loc=SourceLocation()) const
Allocate a TypeSourceInfo where all locations have been initialized to a given location, which defaults to the empty location.
Scope * getCurScope() const
Retrieve the parser&#39;s current scope.
Definition: Sema.h:10864
This represents one expression.
Definition: Expr.h:108
int Id
Definition: ASTDiff.cpp:190
ClassTemplateDecl * lookupCoroutineTraits(SourceLocation KwLoc, SourceLocation FuncLoc)
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6824
static InitializedEntity InitializeVariable(VarDecl *Var)
Create the initialization entity for a variable.
StmtResult BuildCoroutineBodyStmt(CoroutineBodyStmt::CtorArgs)
void setInvalidDecl(bool Invalid=true)
setInvalidDecl - Indicates the Decl had a semantic error.
Definition: DeclBase.cpp:131
Defines the clang::Preprocessor interface.
DeclContext * getDeclContext()
Definition: DeclBase.h:429
ExprResult BuildCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind, TypeSourceInfo *Ty, Expr *E, SourceRange AngleBrackets, SourceRange Parens)
Definition: SemaCast.cpp:257
static bool IsOverloaded(const UnresolvedSetImpl &Functions)
FunctionDecl * getDirectCallee()
If the callee is a FunctionDecl, return it. Otherwise return null.
Definition: Expr.h:2565
Represents a C++ template name within the type system.
Definition: TemplateName.h:178
decls_iterator decls_begin() const
Definition: ExprCXX.h:2726
bool RequireCompleteType(SourceLocation Loc, QualType T, TypeDiagnoser &Diagnoser)
Ensure that the type T is a complete type.
Definition: SemaType.cpp:7659
static bool isValidCoroutineContext(Sema &S, SourceLocation Loc, StringRef Keyword)
QualType getType() const
Definition: Expr.h:130
bool buildStatements()
Build the coroutine body statements, including the "promise dependent" statements when the promise ty...
DeclarationName getCXXOperatorName(OverloadedOperatorKind Op)
Get the name of the overloadable C++ operator corresponding to Op.
static FunctionScopeInfo * checkCoroutineContext(Sema &S, SourceLocation Loc, StringRef Keyword, bool IsImplicit=false)
Check that this is a context in which a coroutine suspension can appear.
ReturnStmt - This represents a return, optionally of an expression: return; return 4;...
Definition: Stmt.h:2462
static Expr * buildBuiltinCall(Sema &S, SourceLocation Loc, Builtin::ID Id, MultiExprArg CallArgs)
bool isInvalid() const
Definition: Ownership.h:166
bool isUsable() const
Definition: Ownership.h:167
QualType getTypeDeclType(const TypeDecl *Decl, const TypeDecl *PrevDecl=nullptr) const
Return the unique reference to the type for the specified type declaration.
Definition: ASTContext.h:1395
The result type of a method or function.
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:699
VarDecl * CoroutinePromise
The promise object for this coroutine, if any.
Definition: ScopeInfo.h:192
ExprObjectKind getObjectKind() const
getObjectKind - The object kind that this expression produces.
Definition: Expr.h:414
static CoroutineBodyStmt * Create(const ASTContext &C, CtorArgs const &Args)
Definition: StmtCXX.cpp:86
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:978
Kind
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:153
QualType getElaboratedType(ElaboratedTypeKeyword Keyword, NestedNameSpecifier *NNS, QualType NamedType, TagDecl *OwnedTagDecl=nullptr) const
Encodes a location in the source.
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
QualType getReturnType() const
Definition: Type.h:3618
void FinalizeDeclaration(Decl *D)
FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform any semantic actions neces...
Definition: SemaDecl.cpp:12022
FunctionDecl * FindUsualDeallocationFunction(SourceLocation StartLoc, bool CanProvideSize, bool Overaligned, DeclarationName Name)
IdentifierTable & getIdentifierTable()
Definition: Preprocessor.h:825
static QualType lookupCoroutineHandleType(Sema &S, QualType PromiseType, SourceLocation Loc)
Look up the std::experimental::coroutine_handle<PromiseType>.
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2048
Only look for allocation functions in the scope of the allocated class.
Definition: Sema.h:5296
ArrayRef< Stmt * > ParamMoves
Definition: StmtCXX.h:344
Describes the kind of initialization being performed, along with location information for tokens rela...
SourceLocation FirstCoroutineStmtLoc
First coroutine statement in the current function.
Definition: ScopeInfo.h:164
QualType BuildReferenceType(QualType T, bool LValueRef, SourceLocation Loc, DeclarationName Entity)
Build a reference type.
Definition: SemaType.cpp:1982
An rvalue ref-qualifier was provided (&&).
Definition: Type.h:1368
void addArgument(const TemplateArgumentLoc &Loc)
Definition: TemplateBase.h:594
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:214
bool isPlaceholderType() const
Test for a type which does not represent an actual type-system type but is instead used as a placehol...
Definition: Type.h:6527
Represents a template argument.
Definition: TemplateBase.h:50
Dataflow Directional Tag Classes.
bool isValid() const
Return true if this is a valid SourceLocation object.
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1265
void clearDelayedTypo(TypoExpr *TE)
Clears the state of the given TypoExpr.
CoroutineStmtBuilder(Sema &S, FunctionDecl &FD, sema::FunctionScopeInfo &Fn, Stmt *Body)
Construct a CoroutineStmtBuilder and initialize the promise statement and initial/final suspends from...
Represents a &#39;co_yield&#39; expression.
Definition: ExprCXX.h:4501
The name of a declaration.
NamedDecl * getFoundDecl() const
Fetch the unique decl found by this lookup.
Definition: Lookup.h:517
bool isBooleanType() const
Definition: Type.h:6670
A set of unresolved declarations.
ExprResult BuildUnresolvedCoawaitExpr(SourceLocation KwLoc, Expr *E, UnresolvedLookupExpr *Lookup)
QualType getCallReturnType(const ASTContext &Ctx) const
getCallReturnType - Get the return type of the call expr.
Definition: Expr.cpp:1395
DeclarationNameInfo - A collector data type for bundling together a DeclarationName and the correspnd...
void AddInitializerToDecl(Decl *dcl, Expr *init, bool DirectInit)
AddInitializerToDecl - Adds the initializer Init to the declaration dcl.
Definition: SemaDecl.cpp:10990
static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType, SourceLocation Loc)
SourceLocation FirstReturnLoc
First &#39;return&#39; statement in the current function.
Definition: ScopeInfo.h:167
StmtResult ActOnFinishFullStmt(Stmt *Stmt)
const UnresolvedSetImpl & asUnresolvedSet() const
Definition: Lookup.h:331
Represents the body of a coroutine.
Definition: StmtCXX.h:301
Location wrapper for a TemplateArgument.
Definition: TemplateBase.h:449
ExprResult ActOnCoawaitExpr(Scope *S, SourceLocation KwLoc, Expr *E)
Look for allocation functions in both the global scope and in the scope of the allocated class...
Definition: Sema.h:5299
CanQualType DependentTy
Definition: ASTContext.h:1044
Represents a &#39;co_await&#39; expression.
Definition: ExprCXX.h:4418
static ExprResult buildOperatorCoawaitLookupExpr(Sema &SemaRef, Scope *S, SourceLocation Loc)
ExprResult BuildCoyieldExpr(SourceLocation KwLoc, Expr *E)
ExprResult CreateBuiltinUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc, Expr *InputExpr)
Definition: SemaExpr.cpp:12988
ExprResult ActOnCoyieldExpr(Scope *S, SourceLocation KwLoc, Expr *E)
bool isClassType() const
Definition: Type.cpp:437
bool LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, bool InUnqualifiedLookup=false)
Perform qualified name lookup into a given context.
Call-style initialization (C++98)
Definition: Decl.h:820
ExprResult PerformMoveOrCopyInitialization(const InitializedEntity &Entity, const VarDecl *NRVOCandidate, QualType ResultType, Expr *Value, bool AllowNRVO=true)
Perform the initialization of a potentially-movable value, which is the result of return value...
Definition: SemaStmt.cpp:3071
ExprResult BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK, SourceLocation Loc, const CXXScopeSpec *SS=nullptr)
Definition: SemaExpr.cpp:1788
Describes the sequence of initializations required to initialize a given object or reference with a s...
Only look for allocation functions in the global scope.
Definition: Sema.h:5293
Represents a C++ struct/union/class.
Definition: DeclCXX.h:299
QualType getRValueReferenceType(QualType T) const
Return the uniqued reference to the type for an rvalue reference to the specified type...
bool isVoidType() const
Definition: Type.h:6553
sema::FunctionScopeInfo * getCurFunction() const
Definition: Sema.h:1392
Builtin::Context & BuiltinInfo
Definition: ASTContext.h:567
DeclContext * CurContext
CurContext - This is the current declaration context of parsing.
Definition: Sema.h:370
Declaration of a class template.
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:251
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2429
ExprResult ExprError()
Definition: Ownership.h:279
bool isDependentType() const
Whether this type is a dependent type, meaning that its definition somehow depends on a template para...
Definition: Type.h:2081
bool hasInvalidCoroutineSuspends() const
Definition: ScopeInfo.h:475
void CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body)
void suppressDiagnostics()
Suppress the diagnostics that would normally fire because of this lookup.
Definition: Lookup.h:583
ExprResult BuildResolvedCoawaitExpr(SourceLocation KwLoc, Expr *E, bool IsImplicit=false)
bool buildDependentStatements()
Build the coroutine body statements that require a non-dependent promise type in order to construct...
QualType getType() const
Definition: Decl.h:647
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:113
A trivial tuple used to represent a source range.
ASTContext & Context
Definition: Sema.h:358
This represents a decl that may have a name.
Definition: Decl.h:248
No keyword precedes the qualified type name.
Definition: Type.h:5076
Describes an entity that is being initialized.
Look up of an operator name (e.g., operator+) for use with operator overloading.
Definition: Sema.h:3130
NamedDecl * getRepresentativeDecl() const
Fetches a representative decl. Useful for lazy diagnostics.
Definition: Lookup.h:524
Decl * getCalleeDecl()
Definition: Expr.h:2559
decls_iterator decls_end() const
Definition: ExprCXX.h:2729
static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD, SourceLocation Loc, bool &Res)
SourceLocation getLocation() const
Definition: DeclBase.h:420
LangStandard::Kind Std
VarDecl * buildCoroutinePromise(SourceLocation Loc)
static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn)