clang  9.0.0svn
SemaCoroutine.cpp
Go to the documentation of this file.
1 //===-- SemaCoroutine.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  // [expr.await]p2 dictates that 'co_await' and 'co_yield' must be used within
189  // a function body.
190  // FIXME: This also covers [expr.await]p2: "An await-expression shall not
191  // appear in a default argument." But the diagnostic QoI here could be
192  // improved to inform the user that default arguments specifically are not
193  // allowed.
194  auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
195  if (!FD) {
196  S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
197  ? diag::err_coroutine_objc_method
198  : diag::err_coroutine_outside_function) << Keyword;
199  return false;
200  }
201 
202  // An enumeration for mapping the diagnostic type to the correct diagnostic
203  // selection index.
204  enum InvalidFuncDiag {
205  DiagCtor = 0,
206  DiagDtor,
207  DiagCopyAssign,
208  DiagMoveAssign,
209  DiagMain,
210  DiagConstexpr,
211  DiagAutoRet,
212  DiagVarargs,
213  };
214  bool Diagnosed = false;
215  auto DiagInvalid = [&](InvalidFuncDiag ID) {
216  S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
217  Diagnosed = true;
218  return false;
219  };
220 
221  // Diagnose when a constructor, destructor, copy/move assignment operator,
222  // or the function 'main' are declared as a coroutine.
223  auto *MD = dyn_cast<CXXMethodDecl>(FD);
224  // [class.ctor]p6: "A constructor shall not be a coroutine."
225  if (MD && isa<CXXConstructorDecl>(MD))
226  return DiagInvalid(DiagCtor);
227  // [class.dtor]p17: "A destructor shall not be a coroutine."
228  else if (MD && isa<CXXDestructorDecl>(MD))
229  return DiagInvalid(DiagDtor);
230  // N4499 [special]p6: "A special member function shall not be a coroutine."
231  // Per C++ [special]p1, special member functions are the "default constructor,
232  // copy constructor and copy assignment operator, move constructor and move
233  // assignment operator, and destructor."
234  else if (MD && MD->isCopyAssignmentOperator())
235  return DiagInvalid(DiagCopyAssign);
236  else if (MD && MD->isMoveAssignmentOperator())
237  return DiagInvalid(DiagMoveAssign);
238  // [basic.start.main]p3: "The function main shall not be a coroutine."
239  else if (FD->isMain())
240  return DiagInvalid(DiagMain);
241 
242  // Emit a diagnostics for each of the following conditions which is not met.
243  // [expr.const]p2: "An expression e is a core constant expression unless the
244  // evaluation of e [...] would evaluate one of the following expressions:
245  // [...] an await-expression [...] a yield-expression."
246  if (FD->isConstexpr())
247  DiagInvalid(DiagConstexpr);
248  // [dcl.spec.auto]p15: "A function declared with a return type that uses a
249  // placeholder type shall not be a coroutine."
250  if (FD->getReturnType()->isUndeducedType())
251  DiagInvalid(DiagAutoRet);
252  // [dcl.fct.def.coroutine]p1: "The parameter-declaration-clause of the
253  // coroutine shall not terminate with an ellipsis that is not part of a
254  // parameter-declaration."
255  if (FD->isVariadic())
256  DiagInvalid(DiagVarargs);
257 
258  return !Diagnosed;
259 }
260 
262  SourceLocation Loc) {
263  DeclarationName OpName =
264  SemaRef.Context.DeclarationNames.getCXXOperatorName(OO_Coawait);
265  LookupResult Operators(SemaRef, OpName, SourceLocation(),
267  SemaRef.LookupName(Operators, S);
268 
269  assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
270  const auto &Functions = Operators.asUnresolvedSet();
271  bool IsOverloaded =
272  Functions.size() > 1 ||
273  (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
274  Expr *CoawaitOp = UnresolvedLookupExpr::Create(
275  SemaRef.Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(),
276  DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded,
277  Functions.begin(), Functions.end());
278  assert(CoawaitOp);
279  return CoawaitOp;
280 }
281 
282 /// Build a call to 'operator co_await' if there is a suitable operator for
283 /// the given expression.
285  Expr *E,
286  UnresolvedLookupExpr *Lookup) {
287  UnresolvedSet<16> Functions;
288  Functions.append(Lookup->decls_begin(), Lookup->decls_end());
289  return SemaRef.CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E);
290 }
291 
293  SourceLocation Loc, Expr *E) {
294  ExprResult R = buildOperatorCoawaitLookupExpr(SemaRef, S, Loc);
295  if (R.isInvalid())
296  return ExprError();
297  return buildOperatorCoawaitCall(SemaRef, Loc, E,
298  cast<UnresolvedLookupExpr>(R.get()));
299 }
300 
302  MultiExprArg CallArgs) {
303  StringRef Name = S.Context.BuiltinInfo.getName(Id);
305  S.LookupName(R, S.TUScope, /*AllowBuiltinCreation=*/true);
306 
307  auto *BuiltInDecl = R.getAsSingle<FunctionDecl>();
308  assert(BuiltInDecl && "failed to find builtin declaration");
309 
310  ExprResult DeclRef =
311  S.BuildDeclRefExpr(BuiltInDecl, BuiltInDecl->getType(), VK_LValue, Loc);
312  assert(DeclRef.isUsable() && "Builtin reference cannot fail");
313 
314  ExprResult Call =
315  S.BuildCallExpr(/*Scope=*/nullptr, DeclRef.get(), Loc, CallArgs, Loc);
316 
317  assert(!Call.isInvalid() && "Call to builtin cannot fail!");
318  return Call.get();
319 }
320 
322  SourceLocation Loc) {
323  QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
324  if (CoroHandleType.isNull())
325  return ExprError();
326 
327  DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType);
328  LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc,
330  if (!S.LookupQualifiedName(Found, LookupCtx)) {
331  S.Diag(Loc, diag::err_coroutine_handle_missing_member)
332  << "from_address";
333  return ExprError();
334  }
335 
336  Expr *FramePtr =
337  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
338 
339  CXXScopeSpec SS;
340  ExprResult FromAddr =
341  S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
342  if (FromAddr.isInvalid())
343  return ExprError();
344 
345  return S.BuildCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc);
346 }
347 
349  enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
350  Expr *Results[3];
352  bool IsInvalid;
353 };
354 
356  StringRef Name, MultiExprArg Args) {
357  DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc);
358 
359  // FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&.
360  CXXScopeSpec SS;
362  Base, Base->getType(), Loc, /*IsPtr=*/false, SS,
363  SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr,
364  /*Scope=*/nullptr);
365  if (Result.isInvalid())
366  return ExprError();
367 
368  // We meant exactly what we asked for. No need for typo correction.
369  if (auto *TE = dyn_cast<TypoExpr>(Result.get())) {
370  S.clearDelayedTypo(TE);
371  S.Diag(Loc, diag::err_no_member)
372  << NameInfo.getName() << Base->getType()->getAsCXXRecordDecl()
373  << Base->getSourceRange();
374  return ExprError();
375  }
376 
377  return S.BuildCallExpr(nullptr, Result.get(), Loc, Args, Loc, nullptr);
378 }
379 
380 // See if return type is coroutine-handle and if so, invoke builtin coro-resume
381 // on its address. This is to enable experimental support for coroutine-handle
382 // returning await_suspend that results in a guaranteed tail call to the target
383 // coroutine.
384 static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
385  SourceLocation Loc) {
386  if (RetType->isReferenceType())
387  return nullptr;
388  Type const *T = RetType.getTypePtr();
389  if (!T->isClassType() && !T->isStructureType())
390  return nullptr;
391 
392  // FIXME: Add convertability check to coroutine_handle<>. Possibly via
393  // EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment
394  // a private function in SemaExprCXX.cpp
395 
396  ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", None);
397  if (AddressExpr.isInvalid())
398  return nullptr;
399 
400  Expr *JustAddress = AddressExpr.get();
401  // FIXME: Check that the type of AddressExpr is void*
402  return buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_resume,
403  JustAddress);
404 }
405 
406 /// Build calls to await_ready, await_suspend, and await_resume for a co_await
407 /// expression.
409  SourceLocation Loc, Expr *E) {
410  OpaqueValueExpr *Operand = new (S.Context)
411  OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
412 
413  // Assume invalid until we see otherwise.
414  ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/true};
415 
416  ExprResult CoroHandleRes = buildCoroutineHandle(S, CoroPromise->getType(), Loc);
417  if (CoroHandleRes.isInvalid())
418  return Calls;
419  Expr *CoroHandle = CoroHandleRes.get();
420 
421  const StringRef Funcs[] = {"await_ready", "await_suspend", "await_resume"};
422  MultiExprArg Args[] = {None, CoroHandle, None};
423  for (size_t I = 0, N = llvm::array_lengthof(Funcs); I != N; ++I) {
424  ExprResult Result = buildMemberCall(S, Operand, Loc, Funcs[I], Args[I]);
425  if (Result.isInvalid())
426  return Calls;
427  Calls.Results[I] = Result.get();
428  }
429 
430  // Assume the calls are valid; all further checking should make them invalid.
431  Calls.IsInvalid = false;
432 
434  CallExpr *AwaitReady = cast<CallExpr>(Calls.Results[ACT::ACT_Ready]);
435  if (!AwaitReady->getType()->isDependentType()) {
436  // [expr.await]p3 [...]
437  // — await-ready is the expression e.await_ready(), contextually converted
438  // to bool.
439  ExprResult Conv = S.PerformContextuallyConvertToBool(AwaitReady);
440  if (Conv.isInvalid()) {
441  S.Diag(AwaitReady->getDirectCallee()->getBeginLoc(),
442  diag::note_await_ready_no_bool_conversion);
443  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
444  << AwaitReady->getDirectCallee() << E->getSourceRange();
445  Calls.IsInvalid = true;
446  }
447  Calls.Results[ACT::ACT_Ready] = Conv.get();
448  }
449  CallExpr *AwaitSuspend = cast<CallExpr>(Calls.Results[ACT::ACT_Suspend]);
450  if (!AwaitSuspend->getType()->isDependentType()) {
451  // [expr.await]p3 [...]
452  // - await-suspend is the expression e.await_suspend(h), which shall be
453  // a prvalue of type void or bool.
454  QualType RetType = AwaitSuspend->getCallReturnType(S.Context);
455 
456  // Experimental support for coroutine_handle returning await_suspend.
457  if (Expr *TailCallSuspend = maybeTailCall(S, RetType, AwaitSuspend, Loc))
458  Calls.Results[ACT::ACT_Suspend] = TailCallSuspend;
459  else {
460  // non-class prvalues always have cv-unqualified types
461  if (RetType->isReferenceType() ||
462  (!RetType->isBooleanType() && !RetType->isVoidType())) {
463  S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(),
464  diag::err_await_suspend_invalid_return_type)
465  << RetType;
466  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
467  << AwaitSuspend->getDirectCallee();
468  Calls.IsInvalid = true;
469  }
470  }
471  }
472 
473  return Calls;
474 }
475 
477  SourceLocation Loc, StringRef Name,
478  MultiExprArg Args) {
479 
480  // Form a reference to the promise.
481  ExprResult PromiseRef = S.BuildDeclRefExpr(
482  Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc);
483  if (PromiseRef.isInvalid())
484  return ExprError();
485 
486  return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
487 }
488 
490  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
491  auto *FD = cast<FunctionDecl>(CurContext);
492  bool IsThisDependentType = [&] {
493  if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
494  return MD->isInstance() && MD->getThisType()->isDependentType();
495  else
496  return false;
497  }();
498 
499  QualType T = FD->getType()->isDependentType() || IsThisDependentType
500  ? Context.DependentTy
501  : lookupPromiseType(*this, FD, Loc);
502  if (T.isNull())
503  return nullptr;
504 
505  auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(),
506  &PP.getIdentifierTable().get("__promise"), T,
507  Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
508  CheckVariableDeclarationType(VD);
509  if (VD->isInvalidDecl())
510  return nullptr;
511 
512  auto *ScopeInfo = getCurFunction();
513  // Build a list of arguments, based on the coroutine functions arguments,
514  // that will be passed to the promise type's constructor.
515  llvm::SmallVector<Expr *, 4> CtorArgExprs;
516 
517  // Add implicit object parameter.
518  if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
519  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
520  ExprResult ThisExpr = ActOnCXXThis(Loc);
521  if (ThisExpr.isInvalid())
522  return nullptr;
523  ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
524  if (ThisExpr.isInvalid())
525  return nullptr;
526  CtorArgExprs.push_back(ThisExpr.get());
527  }
528  }
529 
530  auto &Moves = ScopeInfo->CoroutineParameterMoves;
531  for (auto *PD : FD->parameters()) {
532  if (PD->getType()->isDependentType())
533  continue;
534 
535  auto RefExpr = ExprEmpty();
536  auto Move = Moves.find(PD);
537  assert(Move != Moves.end() &&
538  "Coroutine function parameter not inserted into move map");
539  // If a reference to the function parameter exists in the coroutine
540  // frame, use that reference.
541  auto *MoveDecl =
542  cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl());
543  RefExpr =
544  BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(),
545  ExprValueKind::VK_LValue, FD->getLocation());
546  if (RefExpr.isInvalid())
547  return nullptr;
548  CtorArgExprs.push_back(RefExpr.get());
549  }
550 
551  // Create an initialization sequence for the promise type using the
552  // constructor arguments, wrapped in a parenthesized list expression.
553  Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(),
554  CtorArgExprs, FD->getLocation());
557  VD->getLocation(), /*DirectInit=*/true, PLE);
558  InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs,
559  /*TopLevelOfInitList=*/false,
560  /*TreatUnavailableAsInvalid=*/false);
561 
562  // Attempt to initialize the promise type with the arguments.
563  // If that fails, fall back to the promise type's default constructor.
564  if (InitSeq) {
565  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs);
566  if (Result.isInvalid()) {
567  VD->setInvalidDecl();
568  } else if (Result.get()) {
569  VD->setInit(MaybeCreateExprWithCleanups(Result.get()));
570  VD->setInitStyle(VarDecl::CallInit);
571  CheckCompleteVariableDeclaration(VD);
572  }
573  } else
574  ActOnUninitializedDecl(VD);
575 
576  FD->addDecl(VD);
577  return VD;
578 }
579 
580 /// Check that this is a context in which a coroutine suspension can appear.
582  StringRef Keyword,
583  bool IsImplicit = false) {
584  if (!isValidCoroutineContext(S, Loc, Keyword))
585  return nullptr;
586 
587  assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope");
588 
589  auto *ScopeInfo = S.getCurFunction();
590  assert(ScopeInfo && "missing function scope for function");
591 
592  if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit)
593  ScopeInfo->setFirstCoroutineStmt(Loc, Keyword);
594 
595  if (ScopeInfo->CoroutinePromise)
596  return ScopeInfo;
597 
598  if (!S.buildCoroutineParameterMoves(Loc))
599  return nullptr;
600 
601  ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc);
602  if (!ScopeInfo->CoroutinePromise)
603  return nullptr;
604 
605  return ScopeInfo;
606 }
607 
609  StringRef Keyword) {
610  if (!checkCoroutineContext(*this, KWLoc, Keyword))
611  return false;
612  auto *ScopeInfo = getCurFunction();
613  assert(ScopeInfo->CoroutinePromise);
614 
615  // If we have existing coroutine statements then we have already built
616  // the initial and final suspend points.
617  if (!ScopeInfo->NeedsCoroutineSuspends)
618  return true;
619 
620  ScopeInfo->setNeedsCoroutineSuspends(false);
621 
622  auto *Fn = cast<FunctionDecl>(CurContext);
623  SourceLocation Loc = Fn->getLocation();
624  // Build the initial suspend point
625  auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
626  ExprResult Suspend =
627  buildPromiseCall(*this, ScopeInfo->CoroutinePromise, Loc, Name, None);
628  if (Suspend.isInvalid())
629  return StmtError();
630  Suspend = buildOperatorCoawaitCall(*this, SC, Loc, Suspend.get());
631  if (Suspend.isInvalid())
632  return StmtError();
633  Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),
634  /*IsImplicit*/ true);
635  Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
636  if (Suspend.isInvalid()) {
637  Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
638  << ((Name == "initial_suspend") ? 0 : 1);
639  Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
640  return StmtError();
641  }
642  return cast<Stmt>(Suspend.get());
643  };
644 
645  StmtResult InitSuspend = buildSuspends("initial_suspend");
646  if (InitSuspend.isInvalid())
647  return true;
648 
649  StmtResult FinalSuspend = buildSuspends("final_suspend");
650  if (FinalSuspend.isInvalid())
651  return true;
652 
653  ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());
654 
655  return true;
656 }
657 
658 // Recursively walks up the scope hierarchy until either a 'catch' or a function
659 // scope is found, whichever comes first.
660 static bool isWithinCatchScope(Scope *S) {
661  // 'co_await' and 'co_yield' keywords are disallowed within catch blocks, but
662  // lambdas that use 'co_await' are allowed. The loop below ends when a
663  // function scope is found in order to ensure the following behavior:
664  //
665  // void foo() { // <- function scope
666  // try { //
667  // co_await x; // <- 'co_await' is OK within a function scope
668  // } catch { // <- catch scope
669  // co_await x; // <- 'co_await' is not OK within a catch scope
670  // []() { // <- function scope
671  // co_await x; // <- 'co_await' is OK within a function scope
672  // }();
673  // }
674  // }
675  while (S && !(S->getFlags() & Scope::FnScope)) {
676  if (S->getFlags() & Scope::CatchScope)
677  return true;
678  S = S->getParent();
679  }
680  return false;
681 }
682 
683 // [expr.await]p2, emphasis added: "An await-expression shall appear only in
684 // a *potentially evaluated* expression within the compound-statement of a
685 // function-body *outside of a handler* [...] A context within a function
686 // where an await-expression can appear is called a suspension context of the
687 // function."
689  StringRef Keyword) {
690  // First emphasis of [expr.await]p2: must be a potentially evaluated context.
691  // That is, 'co_await' and 'co_yield' cannot appear in subexpressions of
692  // \c sizeof.
693  if (S.isUnevaluatedContext())
694  S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
695 
696  // Second emphasis of [expr.await]p2: must be outside of an exception handler.
698  S.Diag(Loc, diag::err_coroutine_within_handler) << Keyword;
699 }
700 
702  if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) {
703  CorrectDelayedTyposInExpr(E);
704  return ExprError();
705  }
706 
707  checkSuspensionContext(*this, Loc, "co_await");
708 
709  if (E->getType()->isPlaceholderType()) {
710  ExprResult R = CheckPlaceholderExpr(E);
711  if (R.isInvalid()) return ExprError();
712  E = R.get();
713  }
714  ExprResult Lookup = buildOperatorCoawaitLookupExpr(*this, S, Loc);
715  if (Lookup.isInvalid())
716  return ExprError();
717  return BuildUnresolvedCoawaitExpr(Loc, E,
718  cast<UnresolvedLookupExpr>(Lookup.get()));
719 }
720 
722  UnresolvedLookupExpr *Lookup) {
723  auto *FSI = checkCoroutineContext(*this, Loc, "co_await");
724  if (!FSI)
725  return ExprError();
726 
727  if (E->getType()->isPlaceholderType()) {
728  ExprResult R = CheckPlaceholderExpr(E);
729  if (R.isInvalid())
730  return ExprError();
731  E = R.get();
732  }
733 
734  auto *Promise = FSI->CoroutinePromise;
735  if (Promise->getType()->isDependentType()) {
736  Expr *Res =
737  new (Context) DependentCoawaitExpr(Loc, Context.DependentTy, E, Lookup);
738  return Res;
739  }
740 
741  auto *RD = Promise->getType()->getAsCXXRecordDecl();
742  if (lookupMember(*this, "await_transform", RD, Loc)) {
743  ExprResult R = buildPromiseCall(*this, Promise, Loc, "await_transform", E);
744  if (R.isInvalid()) {
745  Diag(Loc,
746  diag::note_coroutine_promise_implicit_await_transform_required_here)
747  << E->getSourceRange();
748  return ExprError();
749  }
750  E = R.get();
751  }
752  ExprResult Awaitable = buildOperatorCoawaitCall(*this, Loc, E, Lookup);
753  if (Awaitable.isInvalid())
754  return ExprError();
755 
756  return BuildResolvedCoawaitExpr(Loc, Awaitable.get());
757 }
758 
760  bool IsImplicit) {
761  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit);
762  if (!Coroutine)
763  return ExprError();
764 
765  if (E->getType()->isPlaceholderType()) {
766  ExprResult R = CheckPlaceholderExpr(E);
767  if (R.isInvalid()) return ExprError();
768  E = R.get();
769  }
770 
771  if (E->getType()->isDependentType()) {
772  Expr *Res = new (Context)
773  CoawaitExpr(Loc, Context.DependentTy, E, IsImplicit);
774  return Res;
775  }
776 
777  // If the expression is a temporary, materialize it as an lvalue so that we
778  // can use it multiple times.
779  if (E->getValueKind() == VK_RValue)
780  E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
781 
782  // The location of the `co_await` token cannot be used when constructing
783  // the member call expressions since it's before the location of `Expr`, which
784  // is used as the start of the member call expression.
785  SourceLocation CallLoc = E->getExprLoc();
786 
787  // Build the await_ready, await_suspend, await_resume calls.
789  buildCoawaitCalls(*this, Coroutine->CoroutinePromise, CallLoc, E);
790  if (RSS.IsInvalid)
791  return ExprError();
792 
793  Expr *Res =
794  new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
795  RSS.Results[2], RSS.OpaqueValue, IsImplicit);
796 
797  return Res;
798 }
799 
801  if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) {
802  CorrectDelayedTyposInExpr(E);
803  return ExprError();
804  }
805 
806  checkSuspensionContext(*this, Loc, "co_yield");
807 
808  // Build yield_value call.
809  ExprResult Awaitable = buildPromiseCall(
810  *this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E);
811  if (Awaitable.isInvalid())
812  return ExprError();
813 
814  // Build 'operator co_await' call.
815  Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get());
816  if (Awaitable.isInvalid())
817  return ExprError();
818 
819  return BuildCoyieldExpr(Loc, Awaitable.get());
820 }
822  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
823  if (!Coroutine)
824  return ExprError();
825 
826  if (E->getType()->isPlaceholderType()) {
827  ExprResult R = CheckPlaceholderExpr(E);
828  if (R.isInvalid()) return ExprError();
829  E = R.get();
830  }
831 
832  if (E->getType()->isDependentType()) {
833  Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, E);
834  return Res;
835  }
836 
837  // If the expression is a temporary, materialize it as an lvalue so that we
838  // can use it multiple times.
839  if (E->getValueKind() == VK_RValue)
840  E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
841 
842  // Build the await_ready, await_suspend, await_resume calls.
844  buildCoawaitCalls(*this, Coroutine->CoroutinePromise, Loc, E);
845  if (RSS.IsInvalid)
846  return ExprError();
847 
848  Expr *Res =
849  new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
850  RSS.Results[2], RSS.OpaqueValue);
851 
852  return Res;
853 }
854 
856  if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) {
857  CorrectDelayedTyposInExpr(E);
858  return StmtError();
859  }
860  return BuildCoreturnStmt(Loc, E);
861 }
862 
864  bool IsImplicit) {
865  auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit);
866  if (!FSI)
867  return StmtError();
868 
869  if (E && E->getType()->isPlaceholderType() &&
870  !E->getType()->isSpecificPlaceholderType(BuiltinType::Overload)) {
871  ExprResult R = CheckPlaceholderExpr(E);
872  if (R.isInvalid()) return StmtError();
873  E = R.get();
874  }
875 
876  // Move the return value if we can
877  if (E) {
878  auto NRVOCandidate = this->getCopyElisionCandidate(E->getType(), E, CES_AsIfByStdMove);
879  if (NRVOCandidate) {
880  InitializedEntity Entity =
881  InitializedEntity::InitializeResult(Loc, E->getType(), NRVOCandidate);
882  ExprResult MoveResult = this->PerformMoveOrCopyInitialization(
883  Entity, NRVOCandidate, E->getType(), E);
884  if (MoveResult.get())
885  E = MoveResult.get();
886  }
887  }
888 
889  // FIXME: If the operand is a reference to a variable that's about to go out
890  // of scope, we should treat the operand as an xvalue for this overload
891  // resolution.
892  VarDecl *Promise = FSI->CoroutinePromise;
893  ExprResult PC;
894  if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
895  PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
896  } else {
897  E = MakeFullDiscardedValueExpr(E).get();
898  PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
899  }
900  if (PC.isInvalid())
901  return StmtError();
902 
903  Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
904 
905  Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
906  return Res;
907 }
908 
909 /// Look up the std::nothrow object.
912  assert(Std && "Should already be diagnosed");
913 
914  LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
916  if (!S.LookupQualifiedName(Result, Std)) {
917  // FIXME: <experimental/coroutine> should have been included already.
918  // If we require it to include <new> then this diagnostic is no longer
919  // needed.
920  S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
921  return nullptr;
922  }
923 
924  auto *VD = Result.getAsSingle<VarDecl>();
925  if (!VD) {
926  Result.suppressDiagnostics();
927  // We found something weird. Complain about the first thing we found.
928  NamedDecl *Found = *Result.begin();
929  S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
930  return nullptr;
931  }
932 
933  ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
934  if (DR.isInvalid())
935  return nullptr;
936 
937  return DR.get();
938 }
939 
940 // Find an appropriate delete for the promise.
942  QualType PromiseType) {
943  FunctionDecl *OperatorDelete = nullptr;
944 
945  DeclarationName DeleteName =
947 
948  auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
949  assert(PointeeRD && "PromiseType must be a CxxRecordDecl type");
950 
951  if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete))
952  return nullptr;
953 
954  if (!OperatorDelete) {
955  // Look for a global declaration.
956  const bool CanProvideSize = S.isCompleteType(Loc, PromiseType);
957  const bool Overaligned = false;
958  OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
959  Overaligned, DeleteName);
960  }
961  S.MarkFunctionReferenced(Loc, OperatorDelete);
962  return OperatorDelete;
963 }
964 
965 
967  FunctionScopeInfo *Fn = getCurFunction();
968  assert(Fn && Fn->isCoroutine() && "not a coroutine");
969  if (!Body) {
970  assert(FD->isInvalidDecl() &&
971  "a null body is only allowed for invalid declarations");
972  return;
973  }
974  // We have a function that uses coroutine keywords, but we failed to build
975  // the promise type.
976  if (!Fn->CoroutinePromise)
977  return FD->setInvalidDecl();
978 
979  if (isa<CoroutineBodyStmt>(Body)) {
980  // Nothing todo. the body is already a transformed coroutine body statement.
981  return;
982  }
983 
984  // Coroutines [stmt.return]p1:
985  // A return statement shall not appear in a coroutine.
986  if (Fn->FirstReturnLoc.isValid()) {
987  assert(Fn->FirstCoroutineStmtLoc.isValid() &&
988  "first coroutine location not set");
989  Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
990  Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
992  }
993  CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body);
994  if (Builder.isInvalid() || !Builder.buildStatements())
995  return FD->setInvalidDecl();
996 
997  // Build body for the coroutine wrapper statement.
998  Body = CoroutineBodyStmt::Create(Context, Builder);
999 }
1000 
1003  Stmt *Body)
1004  : S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()),
1005  IsPromiseDependentType(
1006  !Fn.CoroutinePromise ||
1007  Fn.CoroutinePromise->getType()->isDependentType()) {
1008  this->Body = Body;
1009 
1010  for (auto KV : Fn.CoroutineParameterMoves)
1011  this->ParamMovesVector.push_back(KV.second);
1012  this->ParamMoves = this->ParamMovesVector;
1013 
1014  if (!IsPromiseDependentType) {
1015  PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl();
1016  assert(PromiseRecordDecl && "Type should have already been checked");
1017  }
1018  this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend();
1019 }
1020 
1022  assert(this->IsValid && "coroutine already invalid");
1023  this->IsValid = makeReturnObject();
1024  if (this->IsValid && !IsPromiseDependentType)
1026  return this->IsValid;
1027 }
1028 
1030  assert(this->IsValid && "coroutine already invalid");
1031  assert(!this->IsPromiseDependentType &&
1032  "coroutine cannot have a dependent promise type");
1033  this->IsValid = makeOnException() && makeOnFallthrough() &&
1034  makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
1035  makeNewAndDeleteExpr();
1036  return this->IsValid;
1037 }
1038 
1039 bool CoroutineStmtBuilder::makePromiseStmt() {
1040  // Form a declaration statement for the promise declaration, so that AST
1041  // visitors can more easily find it.
1042  StmtResult PromiseStmt =
1044  if (PromiseStmt.isInvalid())
1045  return false;
1046 
1047  this->Promise = PromiseStmt.get();
1048  return true;
1049 }
1050 
1051 bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() {
1052  if (Fn.hasInvalidCoroutineSuspends())
1053  return false;
1054  this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first);
1055  this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second);
1056  return true;
1057 }
1058 
1060  CXXRecordDecl *PromiseRecordDecl,
1061  FunctionScopeInfo &Fn) {
1062  auto Loc = E->getExprLoc();
1063  if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) {
1064  auto *Decl = DeclRef->getDecl();
1065  if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) {
1066  if (Method->isStatic())
1067  return true;
1068  else
1069  Loc = Decl->getLocation();
1070  }
1071  }
1072 
1073  S.Diag(
1074  Loc,
1075  diag::err_coroutine_promise_get_return_object_on_allocation_failure)
1076  << PromiseRecordDecl;
1077  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1079  return false;
1080 }
1081 
1082 bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
1083  assert(!IsPromiseDependentType &&
1084  "cannot make statement while the promise type is dependent");
1085 
1086  // [dcl.fct.def.coroutine]/8
1087  // The unqualified-id get_return_object_on_allocation_failure is looked up in
1088  // the scope of class P by class member access lookup (3.4.5). ...
1089  // If an allocation function returns nullptr, ... the coroutine return value
1090  // is obtained by a call to ... get_return_object_on_allocation_failure().
1091 
1092  DeclarationName DN =
1093  S.PP.getIdentifierInfo("get_return_object_on_allocation_failure");
1094  LookupResult Found(S, DN, Loc, Sema::LookupMemberName);
1095  if (!S.LookupQualifiedName(Found, PromiseRecordDecl))
1096  return true;
1097 
1098  CXXScopeSpec SS;
1099  ExprResult DeclNameExpr =
1100  S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
1101  if (DeclNameExpr.isInvalid())
1102  return false;
1103 
1104  if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn))
1105  return false;
1106 
1107  ExprResult ReturnObjectOnAllocationFailure =
1108  S.BuildCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc);
1109  if (ReturnObjectOnAllocationFailure.isInvalid())
1110  return false;
1111 
1113  S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
1114  if (ReturnStmt.isInvalid()) {
1115  S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here)
1116  << DN;
1117  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1119  return false;
1120  }
1121 
1122  this->ReturnStmtOnAllocFailure = ReturnStmt.get();
1123  return true;
1124 }
1125 
1126 bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
1127  // Form and check allocation and deallocation calls.
1128  assert(!IsPromiseDependentType &&
1129  "cannot make statement while the promise type is dependent");
1130  QualType PromiseType = Fn.CoroutinePromise->getType();
1131 
1132  if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
1133  return false;
1134 
1135  const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
1136 
1137  // [dcl.fct.def.coroutine]/7
1138  // Lookup allocation functions using a parameter list composed of the
1139  // requested size of the coroutine state being allocated, followed by
1140  // the coroutine function's arguments. If a matching allocation function
1141  // exists, use it. Otherwise, use an allocation function that just takes
1142  // the requested size.
1143 
1144  FunctionDecl *OperatorNew = nullptr;
1145  FunctionDecl *OperatorDelete = nullptr;
1146  FunctionDecl *UnusedResult = nullptr;
1147  bool PassAlignment = false;
1148  SmallVector<Expr *, 1> PlacementArgs;
1149 
1150  // [dcl.fct.def.coroutine]/7
1151  // "The allocation function’s name is looked up in the scope of P.
1152  // [...] If the lookup finds an allocation function in the scope of P,
1153  // overload resolution is performed on a function call created by assembling
1154  // an argument list. The first argument is the amount of space requested,
1155  // and has type std::size_t. The lvalues p1 ... pn are the succeeding
1156  // arguments."
1157  //
1158  // ...where "p1 ... pn" are defined earlier as:
1159  //
1160  // [dcl.fct.def.coroutine]/3
1161  // "For a coroutine f that is a non-static member function, let P1 denote the
1162  // type of the implicit object parameter (13.3.1) and P2 ... Pn be the types
1163  // of the function parameters; otherwise let P1 ... Pn be the types of the
1164  // function parameters. Let p1 ... pn be lvalues denoting those objects."
1165  if (auto *MD = dyn_cast<CXXMethodDecl>(&FD)) {
1166  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
1167  ExprResult ThisExpr = S.ActOnCXXThis(Loc);
1168  if (ThisExpr.isInvalid())
1169  return false;
1170  ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
1171  if (ThisExpr.isInvalid())
1172  return false;
1173  PlacementArgs.push_back(ThisExpr.get());
1174  }
1175  }
1176  for (auto *PD : FD.parameters()) {
1177  if (PD->getType()->isDependentType())
1178  continue;
1179 
1180  // Build a reference to the parameter.
1181  auto PDLoc = PD->getLocation();
1182  ExprResult PDRefExpr =
1183  S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(),
1184  ExprValueKind::VK_LValue, PDLoc);
1185  if (PDRefExpr.isInvalid())
1186  return false;
1187 
1188  PlacementArgs.push_back(PDRefExpr.get());
1189  }
1190  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1191  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1192  /*isArray*/ false, PassAlignment, PlacementArgs,
1193  OperatorNew, UnusedResult, /*Diagnose*/ false);
1194 
1195  // [dcl.fct.def.coroutine]/7
1196  // "If no matching function is found, overload resolution is performed again
1197  // on a function call created by passing just the amount of space required as
1198  // an argument of type std::size_t."
1199  if (!OperatorNew && !PlacementArgs.empty()) {
1200  PlacementArgs.clear();
1201  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1202  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1203  /*isArray*/ false, PassAlignment, PlacementArgs,
1204  OperatorNew, UnusedResult, /*Diagnose*/ false);
1205  }
1206 
1207  // [dcl.fct.def.coroutine]/7
1208  // "The allocation function’s name is looked up in the scope of P. If this
1209  // lookup fails, the allocation function’s name is looked up in the global
1210  // scope."
1211  if (!OperatorNew) {
1212  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Global,
1213  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1214  /*isArray*/ false, PassAlignment, PlacementArgs,
1215  OperatorNew, UnusedResult);
1216  }
1217 
1218  bool IsGlobalOverload =
1219  OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
1220  // If we didn't find a class-local new declaration and non-throwing new
1221  // was is required then we need to lookup the non-throwing global operator
1222  // instead.
1223  if (RequiresNoThrowAlloc && (!OperatorNew || IsGlobalOverload)) {
1224  auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
1225  if (!StdNoThrow)
1226  return false;
1227  PlacementArgs = {StdNoThrow};
1228  OperatorNew = nullptr;
1229  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Both,
1230  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1231  /*isArray*/ false, PassAlignment, PlacementArgs,
1232  OperatorNew, UnusedResult);
1233  }
1234 
1235  if (!OperatorNew)
1236  return false;
1237 
1238  if (RequiresNoThrowAlloc) {
1239  const auto *FT = OperatorNew->getType()->getAs<FunctionProtoType>();
1240  if (!FT->isNothrow(/*ResultIfDependent*/ false)) {
1241  S.Diag(OperatorNew->getLocation(),
1242  diag::err_coroutine_promise_new_requires_nothrow)
1243  << OperatorNew;
1244  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
1245  << OperatorNew;
1246  return false;
1247  }
1248  }
1249 
1250  if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr)
1251  return false;
1252 
1253  Expr *FramePtr =
1254  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
1255 
1256  Expr *FrameSize =
1257  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_size, {});
1258 
1259  // Make new call.
1260 
1261  ExprResult NewRef =
1262  S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
1263  if (NewRef.isInvalid())
1264  return false;
1265 
1266  SmallVector<Expr *, 2> NewArgs(1, FrameSize);
1267  for (auto Arg : PlacementArgs)
1268  NewArgs.push_back(Arg);
1269 
1270  ExprResult NewExpr =
1271  S.BuildCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
1272  NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
1273  if (NewExpr.isInvalid())
1274  return false;
1275 
1276  // Make delete call.
1277 
1278  QualType OpDeleteQualType = OperatorDelete->getType();
1279 
1280  ExprResult DeleteRef =
1281  S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
1282  if (DeleteRef.isInvalid())
1283  return false;
1284 
1285  Expr *CoroFree =
1286  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_free, {FramePtr});
1287 
1288  SmallVector<Expr *, 2> DeleteArgs{CoroFree};
1289 
1290  // Check if we need to pass the size.
1291  const auto *OpDeleteType =
1292  OpDeleteQualType.getTypePtr()->getAs<FunctionProtoType>();
1293  if (OpDeleteType->getNumParams() > 1)
1294  DeleteArgs.push_back(FrameSize);
1295 
1296  ExprResult DeleteExpr =
1297  S.BuildCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
1298  DeleteExpr =
1299  S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
1300  if (DeleteExpr.isInvalid())
1301  return false;
1302 
1303  this->Allocate = NewExpr.get();
1304  this->Deallocate = DeleteExpr.get();
1305 
1306  return true;
1307 }
1308 
1309 bool CoroutineStmtBuilder::makeOnFallthrough() {
1310  assert(!IsPromiseDependentType &&
1311  "cannot make statement while the promise type is dependent");
1312 
1313  // [dcl.fct.def.coroutine]/4
1314  // The unqualified-ids 'return_void' and 'return_value' are looked up in
1315  // the scope of class P. If both are found, the program is ill-formed.
1316  bool HasRVoid, HasRValue;
1317  LookupResult LRVoid =
1318  lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid);
1319  LookupResult LRValue =
1320  lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue);
1321 
1322  StmtResult Fallthrough;
1323  if (HasRVoid && HasRValue) {
1324  // FIXME Improve this diagnostic
1325  S.Diag(FD.getLocation(),
1326  diag::err_coroutine_promise_incompatible_return_functions)
1327  << PromiseRecordDecl;
1328  S.Diag(LRVoid.getRepresentativeDecl()->getLocation(),
1329  diag::note_member_first_declared_here)
1330  << LRVoid.getLookupName();
1331  S.Diag(LRValue.getRepresentativeDecl()->getLocation(),
1332  diag::note_member_first_declared_here)
1333  << LRValue.getLookupName();
1334  return false;
1335  } else if (!HasRVoid && !HasRValue) {
1336  // FIXME: The PDTS currently specifies this case as UB, not ill-formed.
1337  // However we still diagnose this as an error since until the PDTS is fixed.
1338  S.Diag(FD.getLocation(),
1339  diag::err_coroutine_promise_requires_return_function)
1340  << PromiseRecordDecl;
1341  S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1342  << PromiseRecordDecl;
1343  return false;
1344  } else if (HasRVoid) {
1345  // If the unqualified-id return_void is found, flowing off the end of a
1346  // coroutine is equivalent to a co_return with no operand. Otherwise,
1347  // flowing off the end of a coroutine results in undefined behavior.
1348  Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr,
1349  /*IsImplicit*/false);
1350  Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get());
1351  if (Fallthrough.isInvalid())
1352  return false;
1353  }
1354 
1355  this->OnFallthrough = Fallthrough.get();
1356  return true;
1357 }
1358 
1359 bool CoroutineStmtBuilder::makeOnException() {
1360  // Try to form 'p.unhandled_exception();'
1361  assert(!IsPromiseDependentType &&
1362  "cannot make statement while the promise type is dependent");
1363 
1364  const bool RequireUnhandledException = S.getLangOpts().CXXExceptions;
1365 
1366  if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) {
1367  auto DiagID =
1368  RequireUnhandledException
1369  ? diag::err_coroutine_promise_unhandled_exception_required
1370  : diag::
1371  warn_coroutine_promise_unhandled_exception_required_with_exceptions;
1372  S.Diag(Loc, DiagID) << PromiseRecordDecl;
1373  S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1374  << PromiseRecordDecl;
1375  return !RequireUnhandledException;
1376  }
1377 
1378  // If exceptions are disabled, don't try to build OnException.
1379  if (!S.getLangOpts().CXXExceptions)
1380  return true;
1381 
1382  ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
1383  "unhandled_exception", None);
1384  UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
1385  /*DiscardedValue*/ false);
1386  if (UnhandledException.isInvalid())
1387  return false;
1388 
1389  // Since the body of the coroutine will be wrapped in try-catch, it will
1390  // be incompatible with SEH __try if present in a function.
1391  if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) {
1392  S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions);
1393  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1395  return false;
1396  }
1397 
1398  this->OnException = UnhandledException.get();
1399  return true;
1400 }
1401 
1402 bool CoroutineStmtBuilder::makeReturnObject() {
1403  // Build implicit 'p.get_return_object()' expression and form initialization
1404  // of return type from it.
1405  ExprResult ReturnObject =
1406  buildPromiseCall(S, Fn.CoroutinePromise, Loc, "get_return_object", None);
1407  if (ReturnObject.isInvalid())
1408  return false;
1409 
1410  this->ReturnValue = ReturnObject.get();
1411  return true;
1412 }
1413 
1415  if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
1416  auto *MethodDecl = MbrRef->getMethodDecl();
1417  S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here)
1418  << MethodDecl;
1419  }
1420  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1422 }
1423 
1424 bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
1425  assert(!IsPromiseDependentType &&
1426  "cannot make statement while the promise type is dependent");
1427  assert(this->ReturnValue && "ReturnValue must be already formed");
1428 
1429  QualType const GroType = this->ReturnValue->getType();
1430  assert(!GroType->isDependentType() &&
1431  "get_return_object type must no longer be dependent");
1432 
1433  QualType const FnRetType = FD.getReturnType();
1434  assert(!FnRetType->isDependentType() &&
1435  "get_return_object type must no longer be dependent");
1436 
1437  if (FnRetType->isVoidType()) {
1438  ExprResult Res =
1439  S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
1440  if (Res.isInvalid())
1441  return false;
1442 
1443  this->ResultDecl = Res.get();
1444  return true;
1445  }
1446 
1447  if (GroType->isVoidType()) {
1448  // Trigger a nice error message.
1449  InitializedEntity Entity =
1450  InitializedEntity::InitializeResult(Loc, FnRetType, false);
1451  S.PerformMoveOrCopyInitialization(Entity, nullptr, FnRetType, ReturnValue);
1453  return false;
1454  }
1455 
1456  auto *GroDecl = VarDecl::Create(
1457  S.Context, &FD, FD.getLocation(), FD.getLocation(),
1458  &S.PP.getIdentifierTable().get("__coro_gro"), GroType,
1459  S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
1460 
1461  S.CheckVariableDeclarationType(GroDecl);
1462  if (GroDecl->isInvalidDecl())
1463  return false;
1464 
1466  ExprResult Res = S.PerformMoveOrCopyInitialization(Entity, nullptr, GroType,
1467  this->ReturnValue);
1468  if (Res.isInvalid())
1469  return false;
1470 
1471  Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
1472  if (Res.isInvalid())
1473  return false;
1474 
1475  S.AddInitializerToDecl(GroDecl, Res.get(),
1476  /*DirectInit=*/false);
1477 
1478  S.FinalizeDeclaration(GroDecl);
1479 
1480  // Form a declaration statement for the return declaration, so that AST
1481  // visitors can more easily find it.
1482  StmtResult GroDeclStmt =
1483  S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
1484  if (GroDeclStmt.isInvalid())
1485  return false;
1486 
1487  this->ResultDecl = GroDeclStmt.get();
1488 
1489  ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
1490  if (declRef.isInvalid())
1491  return false;
1492 
1493  StmtResult ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
1494  if (ReturnStmt.isInvalid()) {
1496  return false;
1497  }
1498  if (cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl)
1499  GroDecl->setNRVOVariable(true);
1500 
1501  this->ReturnStmt = ReturnStmt.get();
1502  return true;
1503 }
1504 
1505 // Create a static_cast<T&&>(expr).
1506 static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) {
1507  if (T.isNull())
1508  T = E->getType();
1509  QualType TargetType = S.BuildReferenceType(
1510  T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName());
1511  SourceLocation ExprLoc = E->getBeginLoc();
1512  TypeSourceInfo *TargetLoc =
1513  S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc);
1514 
1515  return S
1516  .BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
1517  SourceRange(ExprLoc, ExprLoc), E->getSourceRange())
1518  .get();
1519 }
1520 
1521 /// Build a variable declaration for move parameter.
1523  IdentifierInfo *II) {
1524  TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc);
1525  VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type,
1526  TInfo, SC_None);
1527  Decl->setImplicit();
1528  return Decl;
1529 }
1530 
1531 // Build statements that move coroutine function parameters to the coroutine
1532 // frame, and store them on the function scope info.
1534  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
1535  auto *FD = cast<FunctionDecl>(CurContext);
1536 
1537  auto *ScopeInfo = getCurFunction();
1538  assert(ScopeInfo->CoroutineParameterMoves.empty() &&
1539  "Should not build parameter moves twice");
1540 
1541  for (auto *PD : FD->parameters()) {
1542  if (PD->getType()->isDependentType())
1543  continue;
1544 
1545  ExprResult PDRefExpr =
1546  BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(),
1547  ExprValueKind::VK_LValue, Loc); // FIXME: scope?
1548  if (PDRefExpr.isInvalid())
1549  return false;
1550 
1551  Expr *CExpr = nullptr;
1552  if (PD->getType()->getAsCXXRecordDecl() ||
1553  PD->getType()->isRValueReferenceType())
1554  CExpr = castForMoving(*this, PDRefExpr.get());
1555  else
1556  CExpr = PDRefExpr.get();
1557 
1558  auto D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier());
1559  AddInitializerToDecl(D, CExpr, /*DirectInit=*/true);
1560 
1561  // Convert decl to a statement.
1562  StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc);
1563  if (Stmt.isInvalid())
1564  return false;
1565 
1566  ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get()));
1567  }
1568  return true;
1569 }
1570 
1572  CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args);
1573  if (!Res)
1574  return StmtError();
1575  return Res;
1576 }
1577 
1579  SourceLocation FuncLoc) {
1580  if (!StdCoroutineTraitsCache) {
1581  if (auto StdExp = lookupStdExperimentalNamespace()) {
1582  LookupResult Result(*this,
1583  &PP.getIdentifierTable().get("coroutine_traits"),
1584  FuncLoc, LookupOrdinaryName);
1585  if (!LookupQualifiedName(Result, StdExp)) {
1586  Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
1587  << "std::experimental::coroutine_traits";
1588  return nullptr;
1589  }
1590  if (!(StdCoroutineTraitsCache =
1591  Result.getAsSingle<ClassTemplateDecl>())) {
1592  Result.suppressDiagnostics();
1593  NamedDecl *Found = *Result.begin();
1594  Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits);
1595  return nullptr;
1596  }
1597  }
1598  }
1599  return StdCoroutineTraitsCache;
1600 }
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:552
Represents a function declaration or definition.
Definition: Decl.h:1743
Represents a &#39;co_await&#39; expression while the type of the promise is dependent.
Definition: ExprCXX.h:4657
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:4035
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2549
A (possibly-)qualified type.
Definition: Type.h:639
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:3155
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:456
Stmt - This represents one statement.
Definition: Stmt.h:65
bool isSpecificPlaceholderType(unsigned K) const
Test for a specific placeholder type.
Definition: Type.h:6584
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:1353
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:88
A reference to a name which we were able to look up during parsing but could not resolve to a specifi...
Definition: ExprCXX.h:2950
Scope * TUScope
Translation Unit Scope - useful to Objective-C actions that need to lookup file scope declarations in...
Definition: Sema.h:868
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:6294
The base class of the type hierarchy.
Definition: Type.h:1414
OpaqueValueExpr * OpaqueValue
This indicates that the scope corresponds to a function, which means that labels are set here...
Definition: Scope.h:47
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:14792
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:2316
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6805
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:5471
bool isAmbiguous() const
Definition: Lookup.h:301
bool isInvalidDecl() const
Definition: DeclBase.h:546
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.
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:3907
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:6357
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Decl.h:738
IdentifierTable & Idents
Definition: ASTContext.h:566
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:117
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2276
static ParenListExpr * Create(const ASTContext &Ctx, SourceLocation LParenLoc, ArrayRef< Expr *> Exprs, SourceLocation RParenLoc)
Create a paren list.
Definition: Expr.cpp:4177
bool isCompleteType(SourceLocation Loc, QualType T)
Definition: Sema.h:1721
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:2879
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:6121
ExprResult ActOnCXXThis(SourceLocation loc)
void append(iterator I, iterator E)
Represents a C++ nested-name-specifier or a global scope specifier.
Definition: DeclSpec.h:63
void CheckVariableDeclarationType(VarDecl *NewVD)
Definition: SemaDecl.cpp:7354
Preprocessor & PP
Definition: Sema.h:373
static VarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S)
Definition: Decl.cpp:1952
const LangOptions & getLangOpts() const
Definition: Sema.h:1276
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:7714
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:3163
ExprResult BuildDeclarationNameExpr(const CXXScopeSpec &SS, LookupResult &R, bool NeedsADL, bool AcceptInvalidDecl=false)
Definition: SemaExpr.cpp:2869
static UnresolvedLookupExpr * Create(const ASTContext &Context, CXXRecordDecl *NamingClass, NestedNameSpecifierLoc QualifierLoc, const DeclarationNameInfo &NameInfo, bool RequiresADL, bool Overloaded, UnresolvedSetIterator Begin, UnresolvedSetIterator End)
Definition: ExprCXX.cpp:327
unsigned getFlags() const
getFlags - Return the flags for this scope.
Definition: Scope.h:220
QualType CheckTemplateIdType(TemplateName Template, SourceLocation TemplateLoc, TemplateArgumentListInfo &TemplateArgs)
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:328
StmtResult ActOnDeclStmt(DeclGroupPtrTy Decl, SourceLocation StartLoc, SourceLocation EndLoc)
Definition: SemaStmt.cpp:72
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1636
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3699
StmtResult BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp)
Definition: SemaStmt.cpp:3529
StmtResult ActOnCoreturnStmt(Scope *S, SourceLocation KwLoc, Expr *E)
DeclarationNameTable DeclarationNames
Definition: ASTContext.h:569
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:11001
This represents one expression.
Definition: Expr.h:108
int Id
Definition: ASTDiff.cpp:190
ClassTemplateDecl * lookupCoroutineTraits(SourceLocation KwLoc, SourceLocation FuncLoc)
ExprResult BuildCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc, MultiExprArg ArgExprs, SourceLocation RParenLoc, Expr *ExecConfig=nullptr, bool IsExecConfig=false)
BuildCallExpr - Handle a call to Fn with the specified array of arguments.
Definition: SemaExpr.cpp:5534
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6870
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.
static bool isWithinCatchScope(Scope *S)
DeclContext * getDeclContext()
Definition: DeclBase.h:431
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:2570
Represents a C++ template name within the type system.
Definition: TemplateName.h:187
decls_iterator decls_begin() const
Definition: ExprCXX.h:2849
bool RequireCompleteType(SourceLocation Loc, QualType T, TypeDiagnoser &Diagnoser)
Ensure that the type T is a complete type.
Definition: SemaType.cpp:7731
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:2562
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:704
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:3625
void FinalizeDeclaration(Decl *D)
FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform any semantic actions neces...
Definition: SemaDecl.cpp:12110
FunctionDecl * FindUsualDeallocationFunction(SourceLocation StartLoc, bool CanProvideSize, bool Overaligned, DeclarationName Name)
IdentifierTable & getIdentifierTable()
Definition: Preprocessor.h:910
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:2108
Only look for allocation functions in the scope of the allocated class.
Definition: Sema.h:5351
ArrayRef< Stmt * > ParamMoves
Definition: StmtCXX.h:360
static void checkSuspensionContext(Sema &S, SourceLocation Loc, StringRef Keyword)
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:2018
An rvalue ref-qualifier was provided (&&).
Definition: Type.h:1373
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:215
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:6571
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:1264
const Scope * getParent() const
getParent - Return the scope that this is nested in.
Definition: Scope.h:228
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:4708
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:6714
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:1398
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:11063
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:317
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:5354
CanQualType DependentTy
Definition: ASTContext.h:1040
Represents a &#39;co_await&#39; expression.
Definition: ExprCXX.h:4621
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:13039
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:3080
ExprResult BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK, SourceLocation Loc, const CXXScopeSpec *SS=nullptr)
Definition: SemaExpr.cpp:1766
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:5348
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:6597
sema::FunctionScopeInfo * getCurFunction() const
Definition: Sema.h:1416
Builtin::Context & BuiltinInfo
Definition: ASTContext.h:568
DeclContext * CurContext
CurContext - This is the current declaration context of parsing.
Definition: Sema.h:386
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:2434
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:2088
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:121
A trivial tuple used to represent a source range.
ASTContext & Context
Definition: Sema.h:374
This is the scope of a C++ catch statement.
Definition: Scope.h:136
This represents a decl that may have a name.
Definition: Decl.h:248
No keyword precedes the qualified type name.
Definition: Type.h:5120
Describes an entity that is being initialized.
Look up of an operator name (e.g., operator+) for use with operator overloading.
Definition: Sema.h:3167
NamedDecl * getRepresentativeDecl() const
Fetches a representative decl. Useful for lazy diagnostics.
Definition: Lookup.h:524
Decl * getCalleeDecl()
Definition: Expr.h:2564
decls_iterator decls_end() const
Definition: ExprCXX.h:2852
static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD, SourceLocation Loc, bool &Res)
SourceLocation getLocation() const
Definition: DeclBase.h:422
LangStandard::Kind Std
VarDecl * buildCoroutinePromise(SourceLocation Loc)
static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn)