clang  10.0.0svn
SemaCoroutine.cpp
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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()->castAs<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  DiagMain,
208  DiagConstexpr,
209  DiagAutoRet,
210  DiagVarargs,
211  DiagConsteval,
212  };
213  bool Diagnosed = false;
214  auto DiagInvalid = [&](InvalidFuncDiag ID) {
215  S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
216  Diagnosed = true;
217  return false;
218  };
219 
220  // Diagnose when a constructor, destructor
221  // or the function 'main' are declared as a coroutine.
222  auto *MD = dyn_cast<CXXMethodDecl>(FD);
223  // [class.ctor]p11: "A constructor shall not be a coroutine."
224  if (MD && isa<CXXConstructorDecl>(MD))
225  return DiagInvalid(DiagCtor);
226  // [class.dtor]p17: "A destructor shall not be a coroutine."
227  else if (MD && isa<CXXDestructorDecl>(MD))
228  return DiagInvalid(DiagDtor);
229  // [basic.start.main]p3: "The function main shall not be a coroutine."
230  else if (FD->isMain())
231  return DiagInvalid(DiagMain);
232 
233  // Emit a diagnostics for each of the following conditions which is not met.
234  // [expr.const]p2: "An expression e is a core constant expression unless the
235  // evaluation of e [...] would evaluate one of the following expressions:
236  // [...] an await-expression [...] a yield-expression."
237  if (FD->isConstexpr())
238  DiagInvalid(FD->isConsteval() ? DiagConsteval : DiagConstexpr);
239  // [dcl.spec.auto]p15: "A function declared with a return type that uses a
240  // placeholder type shall not be a coroutine."
241  if (FD->getReturnType()->isUndeducedType())
242  DiagInvalid(DiagAutoRet);
243  // [dcl.fct.def.coroutine]p1: "The parameter-declaration-clause of the
244  // coroutine shall not terminate with an ellipsis that is not part of a
245  // parameter-declaration."
246  if (FD->isVariadic())
247  DiagInvalid(DiagVarargs);
248 
249  return !Diagnosed;
250 }
251 
253  SourceLocation Loc) {
254  DeclarationName OpName =
255  SemaRef.Context.DeclarationNames.getCXXOperatorName(OO_Coawait);
256  LookupResult Operators(SemaRef, OpName, SourceLocation(),
258  SemaRef.LookupName(Operators, S);
259 
260  assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
261  const auto &Functions = Operators.asUnresolvedSet();
262  bool IsOverloaded =
263  Functions.size() > 1 ||
264  (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
265  Expr *CoawaitOp = UnresolvedLookupExpr::Create(
266  SemaRef.Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(),
267  DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded,
268  Functions.begin(), Functions.end());
269  assert(CoawaitOp);
270  return CoawaitOp;
271 }
272 
273 /// Build a call to 'operator co_await' if there is a suitable operator for
274 /// the given expression.
276  Expr *E,
277  UnresolvedLookupExpr *Lookup) {
278  UnresolvedSet<16> Functions;
279  Functions.append(Lookup->decls_begin(), Lookup->decls_end());
280  return SemaRef.CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E);
281 }
282 
284  SourceLocation Loc, Expr *E) {
285  ExprResult R = buildOperatorCoawaitLookupExpr(SemaRef, S, Loc);
286  if (R.isInvalid())
287  return ExprError();
288  return buildOperatorCoawaitCall(SemaRef, Loc, E,
289  cast<UnresolvedLookupExpr>(R.get()));
290 }
291 
293  MultiExprArg CallArgs) {
294  StringRef Name = S.Context.BuiltinInfo.getName(Id);
296  S.LookupName(R, S.TUScope, /*AllowBuiltinCreation=*/true);
297 
298  auto *BuiltInDecl = R.getAsSingle<FunctionDecl>();
299  assert(BuiltInDecl && "failed to find builtin declaration");
300 
301  ExprResult DeclRef =
302  S.BuildDeclRefExpr(BuiltInDecl, BuiltInDecl->getType(), VK_LValue, Loc);
303  assert(DeclRef.isUsable() && "Builtin reference cannot fail");
304 
305  ExprResult Call =
306  S.BuildCallExpr(/*Scope=*/nullptr, DeclRef.get(), Loc, CallArgs, Loc);
307 
308  assert(!Call.isInvalid() && "Call to builtin cannot fail!");
309  return Call.get();
310 }
311 
313  SourceLocation Loc) {
314  QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
315  if (CoroHandleType.isNull())
316  return ExprError();
317 
318  DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType);
319  LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc,
321  if (!S.LookupQualifiedName(Found, LookupCtx)) {
322  S.Diag(Loc, diag::err_coroutine_handle_missing_member)
323  << "from_address";
324  return ExprError();
325  }
326 
327  Expr *FramePtr =
328  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
329 
330  CXXScopeSpec SS;
331  ExprResult FromAddr =
332  S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
333  if (FromAddr.isInvalid())
334  return ExprError();
335 
336  return S.BuildCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc);
337 }
338 
340  enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
341  Expr *Results[3];
343  bool IsInvalid;
344 };
345 
347  StringRef Name, MultiExprArg Args) {
348  DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc);
349 
350  // FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&.
351  CXXScopeSpec SS;
353  Base, Base->getType(), Loc, /*IsPtr=*/false, SS,
354  SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr,
355  /*Scope=*/nullptr);
356  if (Result.isInvalid())
357  return ExprError();
358 
359  // We meant exactly what we asked for. No need for typo correction.
360  if (auto *TE = dyn_cast<TypoExpr>(Result.get())) {
361  S.clearDelayedTypo(TE);
362  S.Diag(Loc, diag::err_no_member)
363  << NameInfo.getName() << Base->getType()->getAsCXXRecordDecl()
364  << Base->getSourceRange();
365  return ExprError();
366  }
367 
368  return S.BuildCallExpr(nullptr, Result.get(), Loc, Args, Loc, nullptr);
369 }
370 
371 // See if return type is coroutine-handle and if so, invoke builtin coro-resume
372 // on its address. This is to enable experimental support for coroutine-handle
373 // returning await_suspend that results in a guaranteed tail call to the target
374 // coroutine.
375 static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
376  SourceLocation Loc) {
377  if (RetType->isReferenceType())
378  return nullptr;
379  Type const *T = RetType.getTypePtr();
380  if (!T->isClassType() && !T->isStructureType())
381  return nullptr;
382 
383  // FIXME: Add convertability check to coroutine_handle<>. Possibly via
384  // EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment
385  // a private function in SemaExprCXX.cpp
386 
387  ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", None);
388  if (AddressExpr.isInvalid())
389  return nullptr;
390 
391  Expr *JustAddress = AddressExpr.get();
392  // FIXME: Check that the type of AddressExpr is void*
393  return buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_resume,
394  JustAddress);
395 }
396 
397 /// Build calls to await_ready, await_suspend, and await_resume for a co_await
398 /// expression.
400  SourceLocation Loc, Expr *E) {
401  OpaqueValueExpr *Operand = new (S.Context)
402  OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
403 
404  // Assume invalid until we see otherwise.
405  ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/true};
406 
407  ExprResult CoroHandleRes = buildCoroutineHandle(S, CoroPromise->getType(), Loc);
408  if (CoroHandleRes.isInvalid())
409  return Calls;
410  Expr *CoroHandle = CoroHandleRes.get();
411 
412  const StringRef Funcs[] = {"await_ready", "await_suspend", "await_resume"};
413  MultiExprArg Args[] = {None, CoroHandle, None};
414  for (size_t I = 0, N = llvm::array_lengthof(Funcs); I != N; ++I) {
415  ExprResult Result = buildMemberCall(S, Operand, Loc, Funcs[I], Args[I]);
416  if (Result.isInvalid())
417  return Calls;
418  Calls.Results[I] = Result.get();
419  }
420 
421  // Assume the calls are valid; all further checking should make them invalid.
422  Calls.IsInvalid = false;
423 
425  CallExpr *AwaitReady = cast<CallExpr>(Calls.Results[ACT::ACT_Ready]);
426  if (!AwaitReady->getType()->isDependentType()) {
427  // [expr.await]p3 [...]
428  // — await-ready is the expression e.await_ready(), contextually converted
429  // to bool.
430  ExprResult Conv = S.PerformContextuallyConvertToBool(AwaitReady);
431  if (Conv.isInvalid()) {
432  S.Diag(AwaitReady->getDirectCallee()->getBeginLoc(),
433  diag::note_await_ready_no_bool_conversion);
434  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
435  << AwaitReady->getDirectCallee() << E->getSourceRange();
436  Calls.IsInvalid = true;
437  }
438  Calls.Results[ACT::ACT_Ready] = Conv.get();
439  }
440  CallExpr *AwaitSuspend = cast<CallExpr>(Calls.Results[ACT::ACT_Suspend]);
441  if (!AwaitSuspend->getType()->isDependentType()) {
442  // [expr.await]p3 [...]
443  // - await-suspend is the expression e.await_suspend(h), which shall be
444  // a prvalue of type void or bool.
445  QualType RetType = AwaitSuspend->getCallReturnType(S.Context);
446 
447  // Experimental support for coroutine_handle returning await_suspend.
448  if (Expr *TailCallSuspend = maybeTailCall(S, RetType, AwaitSuspend, Loc))
449  Calls.Results[ACT::ACT_Suspend] = TailCallSuspend;
450  else {
451  // non-class prvalues always have cv-unqualified types
452  if (RetType->isReferenceType() ||
453  (!RetType->isBooleanType() && !RetType->isVoidType())) {
454  S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(),
455  diag::err_await_suspend_invalid_return_type)
456  << RetType;
457  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
458  << AwaitSuspend->getDirectCallee();
459  Calls.IsInvalid = true;
460  }
461  }
462  }
463 
464  return Calls;
465 }
466 
468  SourceLocation Loc, StringRef Name,
469  MultiExprArg Args) {
470 
471  // Form a reference to the promise.
472  ExprResult PromiseRef = S.BuildDeclRefExpr(
473  Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc);
474  if (PromiseRef.isInvalid())
475  return ExprError();
476 
477  return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
478 }
479 
481  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
482  auto *FD = cast<FunctionDecl>(CurContext);
483  bool IsThisDependentType = [&] {
484  if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
485  return MD->isInstance() && MD->getThisType()->isDependentType();
486  else
487  return false;
488  }();
489 
490  QualType T = FD->getType()->isDependentType() || IsThisDependentType
491  ? Context.DependentTy
492  : lookupPromiseType(*this, FD, Loc);
493  if (T.isNull())
494  return nullptr;
495 
496  auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(),
497  &PP.getIdentifierTable().get("__promise"), T,
498  Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
499  CheckVariableDeclarationType(VD);
500  if (VD->isInvalidDecl())
501  return nullptr;
502 
503  auto *ScopeInfo = getCurFunction();
504  // Build a list of arguments, based on the coroutine functions arguments,
505  // that will be passed to the promise type's constructor.
506  llvm::SmallVector<Expr *, 4> CtorArgExprs;
507 
508  // Add implicit object parameter.
509  if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
510  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
511  ExprResult ThisExpr = ActOnCXXThis(Loc);
512  if (ThisExpr.isInvalid())
513  return nullptr;
514  ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
515  if (ThisExpr.isInvalid())
516  return nullptr;
517  CtorArgExprs.push_back(ThisExpr.get());
518  }
519  }
520 
521  auto &Moves = ScopeInfo->CoroutineParameterMoves;
522  for (auto *PD : FD->parameters()) {
523  if (PD->getType()->isDependentType())
524  continue;
525 
526  auto RefExpr = ExprEmpty();
527  auto Move = Moves.find(PD);
528  assert(Move != Moves.end() &&
529  "Coroutine function parameter not inserted into move map");
530  // If a reference to the function parameter exists in the coroutine
531  // frame, use that reference.
532  auto *MoveDecl =
533  cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl());
534  RefExpr =
535  BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(),
536  ExprValueKind::VK_LValue, FD->getLocation());
537  if (RefExpr.isInvalid())
538  return nullptr;
539  CtorArgExprs.push_back(RefExpr.get());
540  }
541 
542  // Create an initialization sequence for the promise type using the
543  // constructor arguments, wrapped in a parenthesized list expression.
544  Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(),
545  CtorArgExprs, FD->getLocation());
548  VD->getLocation(), /*DirectInit=*/true, PLE);
549  InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs,
550  /*TopLevelOfInitList=*/false,
551  /*TreatUnavailableAsInvalid=*/false);
552 
553  // Attempt to initialize the promise type with the arguments.
554  // If that fails, fall back to the promise type's default constructor.
555  if (InitSeq) {
556  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs);
557  if (Result.isInvalid()) {
558  VD->setInvalidDecl();
559  } else if (Result.get()) {
560  VD->setInit(MaybeCreateExprWithCleanups(Result.get()));
561  VD->setInitStyle(VarDecl::CallInit);
562  CheckCompleteVariableDeclaration(VD);
563  }
564  } else
565  ActOnUninitializedDecl(VD);
566 
567  FD->addDecl(VD);
568  return VD;
569 }
570 
571 /// Check that this is a context in which a coroutine suspension can appear.
573  StringRef Keyword,
574  bool IsImplicit = false) {
575  if (!isValidCoroutineContext(S, Loc, Keyword))
576  return nullptr;
577 
578  assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope");
579 
580  auto *ScopeInfo = S.getCurFunction();
581  assert(ScopeInfo && "missing function scope for function");
582 
583  if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit)
584  ScopeInfo->setFirstCoroutineStmt(Loc, Keyword);
585 
586  if (ScopeInfo->CoroutinePromise)
587  return ScopeInfo;
588 
589  if (!S.buildCoroutineParameterMoves(Loc))
590  return nullptr;
591 
592  ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc);
593  if (!ScopeInfo->CoroutinePromise)
594  return nullptr;
595 
596  return ScopeInfo;
597 }
598 
600  StringRef Keyword) {
601  if (!checkCoroutineContext(*this, KWLoc, Keyword))
602  return false;
603  auto *ScopeInfo = getCurFunction();
604  assert(ScopeInfo->CoroutinePromise);
605 
606  // If we have existing coroutine statements then we have already built
607  // the initial and final suspend points.
608  if (!ScopeInfo->NeedsCoroutineSuspends)
609  return true;
610 
611  ScopeInfo->setNeedsCoroutineSuspends(false);
612 
613  auto *Fn = cast<FunctionDecl>(CurContext);
614  SourceLocation Loc = Fn->getLocation();
615  // Build the initial suspend point
616  auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
617  ExprResult Suspend =
618  buildPromiseCall(*this, ScopeInfo->CoroutinePromise, Loc, Name, None);
619  if (Suspend.isInvalid())
620  return StmtError();
621  Suspend = buildOperatorCoawaitCall(*this, SC, Loc, Suspend.get());
622  if (Suspend.isInvalid())
623  return StmtError();
624  Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),
625  /*IsImplicit*/ true);
626  Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
627  if (Suspend.isInvalid()) {
628  Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
629  << ((Name == "initial_suspend") ? 0 : 1);
630  Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
631  return StmtError();
632  }
633  return cast<Stmt>(Suspend.get());
634  };
635 
636  StmtResult InitSuspend = buildSuspends("initial_suspend");
637  if (InitSuspend.isInvalid())
638  return true;
639 
640  StmtResult FinalSuspend = buildSuspends("final_suspend");
641  if (FinalSuspend.isInvalid())
642  return true;
643 
644  ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());
645 
646  return true;
647 }
648 
649 // Recursively walks up the scope hierarchy until either a 'catch' or a function
650 // scope is found, whichever comes first.
651 static bool isWithinCatchScope(Scope *S) {
652  // 'co_await' and 'co_yield' keywords are disallowed within catch blocks, but
653  // lambdas that use 'co_await' are allowed. The loop below ends when a
654  // function scope is found in order to ensure the following behavior:
655  //
656  // void foo() { // <- function scope
657  // try { //
658  // co_await x; // <- 'co_await' is OK within a function scope
659  // } catch { // <- catch scope
660  // co_await x; // <- 'co_await' is not OK within a catch scope
661  // []() { // <- function scope
662  // co_await x; // <- 'co_await' is OK within a function scope
663  // }();
664  // }
665  // }
666  while (S && !(S->getFlags() & Scope::FnScope)) {
667  if (S->getFlags() & Scope::CatchScope)
668  return true;
669  S = S->getParent();
670  }
671  return false;
672 }
673 
674 // [expr.await]p2, emphasis added: "An await-expression shall appear only in
675 // a *potentially evaluated* expression within the compound-statement of a
676 // function-body *outside of a handler* [...] A context within a function
677 // where an await-expression can appear is called a suspension context of the
678 // function."
680  StringRef Keyword) {
681  // First emphasis of [expr.await]p2: must be a potentially evaluated context.
682  // That is, 'co_await' and 'co_yield' cannot appear in subexpressions of
683  // \c sizeof.
684  if (S.isUnevaluatedContext())
685  S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
686 
687  // Second emphasis of [expr.await]p2: must be outside of an exception handler.
689  S.Diag(Loc, diag::err_coroutine_within_handler) << Keyword;
690 }
691 
693  if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) {
694  CorrectDelayedTyposInExpr(E);
695  return ExprError();
696  }
697 
698  checkSuspensionContext(*this, Loc, "co_await");
699 
700  if (E->getType()->isPlaceholderType()) {
701  ExprResult R = CheckPlaceholderExpr(E);
702  if (R.isInvalid()) return ExprError();
703  E = R.get();
704  }
705  ExprResult Lookup = buildOperatorCoawaitLookupExpr(*this, S, Loc);
706  if (Lookup.isInvalid())
707  return ExprError();
708  return BuildUnresolvedCoawaitExpr(Loc, E,
709  cast<UnresolvedLookupExpr>(Lookup.get()));
710 }
711 
713  UnresolvedLookupExpr *Lookup) {
714  auto *FSI = checkCoroutineContext(*this, Loc, "co_await");
715  if (!FSI)
716  return ExprError();
717 
718  if (E->getType()->isPlaceholderType()) {
719  ExprResult R = CheckPlaceholderExpr(E);
720  if (R.isInvalid())
721  return ExprError();
722  E = R.get();
723  }
724 
725  auto *Promise = FSI->CoroutinePromise;
726  if (Promise->getType()->isDependentType()) {
727  Expr *Res =
728  new (Context) DependentCoawaitExpr(Loc, Context.DependentTy, E, Lookup);
729  return Res;
730  }
731 
732  auto *RD = Promise->getType()->getAsCXXRecordDecl();
733  if (lookupMember(*this, "await_transform", RD, Loc)) {
734  ExprResult R = buildPromiseCall(*this, Promise, Loc, "await_transform", E);
735  if (R.isInvalid()) {
736  Diag(Loc,
737  diag::note_coroutine_promise_implicit_await_transform_required_here)
738  << E->getSourceRange();
739  return ExprError();
740  }
741  E = R.get();
742  }
743  ExprResult Awaitable = buildOperatorCoawaitCall(*this, Loc, E, Lookup);
744  if (Awaitable.isInvalid())
745  return ExprError();
746 
747  return BuildResolvedCoawaitExpr(Loc, Awaitable.get());
748 }
749 
751  bool IsImplicit) {
752  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit);
753  if (!Coroutine)
754  return ExprError();
755 
756  if (E->getType()->isPlaceholderType()) {
757  ExprResult R = CheckPlaceholderExpr(E);
758  if (R.isInvalid()) return ExprError();
759  E = R.get();
760  }
761 
762  if (E->getType()->isDependentType()) {
763  Expr *Res = new (Context)
764  CoawaitExpr(Loc, Context.DependentTy, E, IsImplicit);
765  return Res;
766  }
767 
768  // If the expression is a temporary, materialize it as an lvalue so that we
769  // can use it multiple times.
770  if (E->getValueKind() == VK_RValue)
771  E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
772 
773  // The location of the `co_await` token cannot be used when constructing
774  // the member call expressions since it's before the location of `Expr`, which
775  // is used as the start of the member call expression.
776  SourceLocation CallLoc = E->getExprLoc();
777 
778  // Build the await_ready, await_suspend, await_resume calls.
780  buildCoawaitCalls(*this, Coroutine->CoroutinePromise, CallLoc, E);
781  if (RSS.IsInvalid)
782  return ExprError();
783 
784  Expr *Res =
785  new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
786  RSS.Results[2], RSS.OpaqueValue, IsImplicit);
787 
788  return Res;
789 }
790 
792  if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) {
793  CorrectDelayedTyposInExpr(E);
794  return ExprError();
795  }
796 
797  checkSuspensionContext(*this, Loc, "co_yield");
798 
799  // Build yield_value call.
800  ExprResult Awaitable = buildPromiseCall(
801  *this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E);
802  if (Awaitable.isInvalid())
803  return ExprError();
804 
805  // Build 'operator co_await' call.
806  Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get());
807  if (Awaitable.isInvalid())
808  return ExprError();
809 
810  return BuildCoyieldExpr(Loc, Awaitable.get());
811 }
813  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
814  if (!Coroutine)
815  return ExprError();
816 
817  if (E->getType()->isPlaceholderType()) {
818  ExprResult R = CheckPlaceholderExpr(E);
819  if (R.isInvalid()) return ExprError();
820  E = R.get();
821  }
822 
823  if (E->getType()->isDependentType()) {
824  Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, E);
825  return Res;
826  }
827 
828  // If the expression is a temporary, materialize it as an lvalue so that we
829  // can use it multiple times.
830  if (E->getValueKind() == VK_RValue)
831  E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
832 
833  // Build the await_ready, await_suspend, await_resume calls.
835  buildCoawaitCalls(*this, Coroutine->CoroutinePromise, Loc, E);
836  if (RSS.IsInvalid)
837  return ExprError();
838 
839  Expr *Res =
840  new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
841  RSS.Results[2], RSS.OpaqueValue);
842 
843  return Res;
844 }
845 
847  if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) {
848  CorrectDelayedTyposInExpr(E);
849  return StmtError();
850  }
851  return BuildCoreturnStmt(Loc, E);
852 }
853 
855  bool IsImplicit) {
856  auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit);
857  if (!FSI)
858  return StmtError();
859 
860  if (E && E->getType()->isPlaceholderType() &&
861  !E->getType()->isSpecificPlaceholderType(BuiltinType::Overload)) {
862  ExprResult R = CheckPlaceholderExpr(E);
863  if (R.isInvalid()) return StmtError();
864  E = R.get();
865  }
866 
867  // Move the return value if we can
868  if (E) {
869  auto NRVOCandidate = this->getCopyElisionCandidate(E->getType(), E, CES_AsIfByStdMove);
870  if (NRVOCandidate) {
871  InitializedEntity Entity =
872  InitializedEntity::InitializeResult(Loc, E->getType(), NRVOCandidate);
873  ExprResult MoveResult = this->PerformMoveOrCopyInitialization(
874  Entity, NRVOCandidate, E->getType(), E);
875  if (MoveResult.get())
876  E = MoveResult.get();
877  }
878  }
879 
880  // FIXME: If the operand is a reference to a variable that's about to go out
881  // of scope, we should treat the operand as an xvalue for this overload
882  // resolution.
883  VarDecl *Promise = FSI->CoroutinePromise;
884  ExprResult PC;
885  if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
886  PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
887  } else {
888  E = MakeFullDiscardedValueExpr(E).get();
889  PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
890  }
891  if (PC.isInvalid())
892  return StmtError();
893 
894  Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
895 
896  Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
897  return Res;
898 }
899 
900 /// Look up the std::nothrow object.
903  assert(Std && "Should already be diagnosed");
904 
905  LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
907  if (!S.LookupQualifiedName(Result, Std)) {
908  // FIXME: <experimental/coroutine> should have been included already.
909  // If we require it to include <new> then this diagnostic is no longer
910  // needed.
911  S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
912  return nullptr;
913  }
914 
915  auto *VD = Result.getAsSingle<VarDecl>();
916  if (!VD) {
917  Result.suppressDiagnostics();
918  // We found something weird. Complain about the first thing we found.
919  NamedDecl *Found = *Result.begin();
920  S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
921  return nullptr;
922  }
923 
924  ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
925  if (DR.isInvalid())
926  return nullptr;
927 
928  return DR.get();
929 }
930 
931 // Find an appropriate delete for the promise.
933  QualType PromiseType) {
934  FunctionDecl *OperatorDelete = nullptr;
935 
936  DeclarationName DeleteName =
938 
939  auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
940  assert(PointeeRD && "PromiseType must be a CxxRecordDecl type");
941 
942  if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete))
943  return nullptr;
944 
945  if (!OperatorDelete) {
946  // Look for a global declaration.
947  const bool CanProvideSize = S.isCompleteType(Loc, PromiseType);
948  const bool Overaligned = false;
949  OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
950  Overaligned, DeleteName);
951  }
952  S.MarkFunctionReferenced(Loc, OperatorDelete);
953  return OperatorDelete;
954 }
955 
956 
958  FunctionScopeInfo *Fn = getCurFunction();
959  assert(Fn && Fn->isCoroutine() && "not a coroutine");
960  if (!Body) {
961  assert(FD->isInvalidDecl() &&
962  "a null body is only allowed for invalid declarations");
963  return;
964  }
965  // We have a function that uses coroutine keywords, but we failed to build
966  // the promise type.
967  if (!Fn->CoroutinePromise)
968  return FD->setInvalidDecl();
969 
970  if (isa<CoroutineBodyStmt>(Body)) {
971  // Nothing todo. the body is already a transformed coroutine body statement.
972  return;
973  }
974 
975  // Coroutines [stmt.return]p1:
976  // A return statement shall not appear in a coroutine.
977  if (Fn->FirstReturnLoc.isValid()) {
978  assert(Fn->FirstCoroutineStmtLoc.isValid() &&
979  "first coroutine location not set");
980  Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
981  Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
983  }
984  CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body);
985  if (Builder.isInvalid() || !Builder.buildStatements())
986  return FD->setInvalidDecl();
987 
988  // Build body for the coroutine wrapper statement.
989  Body = CoroutineBodyStmt::Create(Context, Builder);
990 }
991 
994  Stmt *Body)
995  : S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()),
996  IsPromiseDependentType(
997  !Fn.CoroutinePromise ||
998  Fn.CoroutinePromise->getType()->isDependentType()) {
999  this->Body = Body;
1000 
1001  for (auto KV : Fn.CoroutineParameterMoves)
1002  this->ParamMovesVector.push_back(KV.second);
1003  this->ParamMoves = this->ParamMovesVector;
1004 
1005  if (!IsPromiseDependentType) {
1006  PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl();
1007  assert(PromiseRecordDecl && "Type should have already been checked");
1008  }
1009  this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend();
1010 }
1011 
1013  assert(this->IsValid && "coroutine already invalid");
1014  this->IsValid = makeReturnObject();
1015  if (this->IsValid && !IsPromiseDependentType)
1017  return this->IsValid;
1018 }
1019 
1021  assert(this->IsValid && "coroutine already invalid");
1022  assert(!this->IsPromiseDependentType &&
1023  "coroutine cannot have a dependent promise type");
1024  this->IsValid = makeOnException() && makeOnFallthrough() &&
1025  makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
1026  makeNewAndDeleteExpr();
1027  return this->IsValid;
1028 }
1029 
1030 bool CoroutineStmtBuilder::makePromiseStmt() {
1031  // Form a declaration statement for the promise declaration, so that AST
1032  // visitors can more easily find it.
1033  StmtResult PromiseStmt =
1035  if (PromiseStmt.isInvalid())
1036  return false;
1037 
1038  this->Promise = PromiseStmt.get();
1039  return true;
1040 }
1041 
1042 bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() {
1043  if (Fn.hasInvalidCoroutineSuspends())
1044  return false;
1045  this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first);
1046  this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second);
1047  return true;
1048 }
1049 
1051  CXXRecordDecl *PromiseRecordDecl,
1052  FunctionScopeInfo &Fn) {
1053  auto Loc = E->getExprLoc();
1054  if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) {
1055  auto *Decl = DeclRef->getDecl();
1056  if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) {
1057  if (Method->isStatic())
1058  return true;
1059  else
1060  Loc = Decl->getLocation();
1061  }
1062  }
1063 
1064  S.Diag(
1065  Loc,
1066  diag::err_coroutine_promise_get_return_object_on_allocation_failure)
1067  << PromiseRecordDecl;
1068  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1070  return false;
1071 }
1072 
1073 bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
1074  assert(!IsPromiseDependentType &&
1075  "cannot make statement while the promise type is dependent");
1076 
1077  // [dcl.fct.def.coroutine]/8
1078  // The unqualified-id get_return_object_on_allocation_failure is looked up in
1079  // the scope of class P by class member access lookup (3.4.5). ...
1080  // If an allocation function returns nullptr, ... the coroutine return value
1081  // is obtained by a call to ... get_return_object_on_allocation_failure().
1082 
1083  DeclarationName DN =
1084  S.PP.getIdentifierInfo("get_return_object_on_allocation_failure");
1085  LookupResult Found(S, DN, Loc, Sema::LookupMemberName);
1086  if (!S.LookupQualifiedName(Found, PromiseRecordDecl))
1087  return true;
1088 
1089  CXXScopeSpec SS;
1090  ExprResult DeclNameExpr =
1091  S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
1092  if (DeclNameExpr.isInvalid())
1093  return false;
1094 
1095  if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn))
1096  return false;
1097 
1098  ExprResult ReturnObjectOnAllocationFailure =
1099  S.BuildCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc);
1100  if (ReturnObjectOnAllocationFailure.isInvalid())
1101  return false;
1102 
1104  S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
1105  if (ReturnStmt.isInvalid()) {
1106  S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here)
1107  << DN;
1108  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1110  return false;
1111  }
1112 
1113  this->ReturnStmtOnAllocFailure = ReturnStmt.get();
1114  return true;
1115 }
1116 
1117 bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
1118  // Form and check allocation and deallocation calls.
1119  assert(!IsPromiseDependentType &&
1120  "cannot make statement while the promise type is dependent");
1121  QualType PromiseType = Fn.CoroutinePromise->getType();
1122 
1123  if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
1124  return false;
1125 
1126  const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
1127 
1128  // [dcl.fct.def.coroutine]/7
1129  // Lookup allocation functions using a parameter list composed of the
1130  // requested size of the coroutine state being allocated, followed by
1131  // the coroutine function's arguments. If a matching allocation function
1132  // exists, use it. Otherwise, use an allocation function that just takes
1133  // the requested size.
1134 
1135  FunctionDecl *OperatorNew = nullptr;
1136  FunctionDecl *OperatorDelete = nullptr;
1137  FunctionDecl *UnusedResult = nullptr;
1138  bool PassAlignment = false;
1139  SmallVector<Expr *, 1> PlacementArgs;
1140 
1141  // [dcl.fct.def.coroutine]/7
1142  // "The allocation function’s name is looked up in the scope of P.
1143  // [...] If the lookup finds an allocation function in the scope of P,
1144  // overload resolution is performed on a function call created by assembling
1145  // an argument list. The first argument is the amount of space requested,
1146  // and has type std::size_t. The lvalues p1 ... pn are the succeeding
1147  // arguments."
1148  //
1149  // ...where "p1 ... pn" are defined earlier as:
1150  //
1151  // [dcl.fct.def.coroutine]/3
1152  // "For a coroutine f that is a non-static member function, let P1 denote the
1153  // type of the implicit object parameter (13.3.1) and P2 ... Pn be the types
1154  // of the function parameters; otherwise let P1 ... Pn be the types of the
1155  // function parameters. Let p1 ... pn be lvalues denoting those objects."
1156  if (auto *MD = dyn_cast<CXXMethodDecl>(&FD)) {
1157  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
1158  ExprResult ThisExpr = S.ActOnCXXThis(Loc);
1159  if (ThisExpr.isInvalid())
1160  return false;
1161  ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
1162  if (ThisExpr.isInvalid())
1163  return false;
1164  PlacementArgs.push_back(ThisExpr.get());
1165  }
1166  }
1167  for (auto *PD : FD.parameters()) {
1168  if (PD->getType()->isDependentType())
1169  continue;
1170 
1171  // Build a reference to the parameter.
1172  auto PDLoc = PD->getLocation();
1173  ExprResult PDRefExpr =
1174  S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(),
1175  ExprValueKind::VK_LValue, PDLoc);
1176  if (PDRefExpr.isInvalid())
1177  return false;
1178 
1179  PlacementArgs.push_back(PDRefExpr.get());
1180  }
1181  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1182  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1183  /*isArray*/ false, PassAlignment, PlacementArgs,
1184  OperatorNew, UnusedResult, /*Diagnose*/ false);
1185 
1186  // [dcl.fct.def.coroutine]/7
1187  // "If no matching function is found, overload resolution is performed again
1188  // on a function call created by passing just the amount of space required as
1189  // an argument of type std::size_t."
1190  if (!OperatorNew && !PlacementArgs.empty()) {
1191  PlacementArgs.clear();
1192  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1193  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1194  /*isArray*/ false, PassAlignment, PlacementArgs,
1195  OperatorNew, UnusedResult, /*Diagnose*/ false);
1196  }
1197 
1198  // [dcl.fct.def.coroutine]/7
1199  // "The allocation function’s name is looked up in the scope of P. If this
1200  // lookup fails, the allocation function’s name is looked up in the global
1201  // scope."
1202  if (!OperatorNew) {
1203  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Global,
1204  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1205  /*isArray*/ false, PassAlignment, PlacementArgs,
1206  OperatorNew, UnusedResult);
1207  }
1208 
1209  bool IsGlobalOverload =
1210  OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
1211  // If we didn't find a class-local new declaration and non-throwing new
1212  // was is required then we need to lookup the non-throwing global operator
1213  // instead.
1214  if (RequiresNoThrowAlloc && (!OperatorNew || IsGlobalOverload)) {
1215  auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
1216  if (!StdNoThrow)
1217  return false;
1218  PlacementArgs = {StdNoThrow};
1219  OperatorNew = nullptr;
1220  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Both,
1221  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1222  /*isArray*/ false, PassAlignment, PlacementArgs,
1223  OperatorNew, UnusedResult);
1224  }
1225 
1226  if (!OperatorNew)
1227  return false;
1228 
1229  if (RequiresNoThrowAlloc) {
1230  const auto *FT = OperatorNew->getType()->getAs<FunctionProtoType>();
1231  if (!FT->isNothrow(/*ResultIfDependent*/ false)) {
1232  S.Diag(OperatorNew->getLocation(),
1233  diag::err_coroutine_promise_new_requires_nothrow)
1234  << OperatorNew;
1235  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
1236  << OperatorNew;
1237  return false;
1238  }
1239  }
1240 
1241  if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr)
1242  return false;
1243 
1244  Expr *FramePtr =
1245  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
1246 
1247  Expr *FrameSize =
1248  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_size, {});
1249 
1250  // Make new call.
1251 
1252  ExprResult NewRef =
1253  S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
1254  if (NewRef.isInvalid())
1255  return false;
1256 
1257  SmallVector<Expr *, 2> NewArgs(1, FrameSize);
1258  for (auto Arg : PlacementArgs)
1259  NewArgs.push_back(Arg);
1260 
1261  ExprResult NewExpr =
1262  S.BuildCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
1263  NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
1264  if (NewExpr.isInvalid())
1265  return false;
1266 
1267  // Make delete call.
1268 
1269  QualType OpDeleteQualType = OperatorDelete->getType();
1270 
1271  ExprResult DeleteRef =
1272  S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
1273  if (DeleteRef.isInvalid())
1274  return false;
1275 
1276  Expr *CoroFree =
1277  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_free, {FramePtr});
1278 
1279  SmallVector<Expr *, 2> DeleteArgs{CoroFree};
1280 
1281  // Check if we need to pass the size.
1282  const auto *OpDeleteType =
1283  OpDeleteQualType.getTypePtr()->getAs<FunctionProtoType>();
1284  if (OpDeleteType->getNumParams() > 1)
1285  DeleteArgs.push_back(FrameSize);
1286 
1287  ExprResult DeleteExpr =
1288  S.BuildCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
1289  DeleteExpr =
1290  S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
1291  if (DeleteExpr.isInvalid())
1292  return false;
1293 
1294  this->Allocate = NewExpr.get();
1295  this->Deallocate = DeleteExpr.get();
1296 
1297  return true;
1298 }
1299 
1300 bool CoroutineStmtBuilder::makeOnFallthrough() {
1301  assert(!IsPromiseDependentType &&
1302  "cannot make statement while the promise type is dependent");
1303 
1304  // [dcl.fct.def.coroutine]/4
1305  // The unqualified-ids 'return_void' and 'return_value' are looked up in
1306  // the scope of class P. If both are found, the program is ill-formed.
1307  bool HasRVoid, HasRValue;
1308  LookupResult LRVoid =
1309  lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid);
1310  LookupResult LRValue =
1311  lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue);
1312 
1313  StmtResult Fallthrough;
1314  if (HasRVoid && HasRValue) {
1315  // FIXME Improve this diagnostic
1316  S.Diag(FD.getLocation(),
1317  diag::err_coroutine_promise_incompatible_return_functions)
1318  << PromiseRecordDecl;
1319  S.Diag(LRVoid.getRepresentativeDecl()->getLocation(),
1320  diag::note_member_first_declared_here)
1321  << LRVoid.getLookupName();
1322  S.Diag(LRValue.getRepresentativeDecl()->getLocation(),
1323  diag::note_member_first_declared_here)
1324  << LRValue.getLookupName();
1325  return false;
1326  } else if (!HasRVoid && !HasRValue) {
1327  // FIXME: The PDTS currently specifies this case as UB, not ill-formed.
1328  // However we still diagnose this as an error since until the PDTS is fixed.
1329  S.Diag(FD.getLocation(),
1330  diag::err_coroutine_promise_requires_return_function)
1331  << PromiseRecordDecl;
1332  S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1333  << PromiseRecordDecl;
1334  return false;
1335  } else if (HasRVoid) {
1336  // If the unqualified-id return_void is found, flowing off the end of a
1337  // coroutine is equivalent to a co_return with no operand. Otherwise,
1338  // flowing off the end of a coroutine results in undefined behavior.
1339  Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr,
1340  /*IsImplicit*/false);
1341  Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get());
1342  if (Fallthrough.isInvalid())
1343  return false;
1344  }
1345 
1346  this->OnFallthrough = Fallthrough.get();
1347  return true;
1348 }
1349 
1350 bool CoroutineStmtBuilder::makeOnException() {
1351  // Try to form 'p.unhandled_exception();'
1352  assert(!IsPromiseDependentType &&
1353  "cannot make statement while the promise type is dependent");
1354 
1355  const bool RequireUnhandledException = S.getLangOpts().CXXExceptions;
1356 
1357  if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) {
1358  auto DiagID =
1359  RequireUnhandledException
1360  ? diag::err_coroutine_promise_unhandled_exception_required
1361  : diag::
1362  warn_coroutine_promise_unhandled_exception_required_with_exceptions;
1363  S.Diag(Loc, DiagID) << PromiseRecordDecl;
1364  S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1365  << PromiseRecordDecl;
1366  return !RequireUnhandledException;
1367  }
1368 
1369  // If exceptions are disabled, don't try to build OnException.
1370  if (!S.getLangOpts().CXXExceptions)
1371  return true;
1372 
1373  ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
1374  "unhandled_exception", None);
1375  UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
1376  /*DiscardedValue*/ false);
1377  if (UnhandledException.isInvalid())
1378  return false;
1379 
1380  // Since the body of the coroutine will be wrapped in try-catch, it will
1381  // be incompatible with SEH __try if present in a function.
1382  if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) {
1383  S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions);
1384  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1386  return false;
1387  }
1388 
1389  this->OnException = UnhandledException.get();
1390  return true;
1391 }
1392 
1393 bool CoroutineStmtBuilder::makeReturnObject() {
1394  // Build implicit 'p.get_return_object()' expression and form initialization
1395  // of return type from it.
1396  ExprResult ReturnObject =
1397  buildPromiseCall(S, Fn.CoroutinePromise, Loc, "get_return_object", None);
1398  if (ReturnObject.isInvalid())
1399  return false;
1400 
1401  this->ReturnValue = ReturnObject.get();
1402  return true;
1403 }
1404 
1406  if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
1407  auto *MethodDecl = MbrRef->getMethodDecl();
1408  S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here)
1409  << MethodDecl;
1410  }
1411  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1413 }
1414 
1415 bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
1416  assert(!IsPromiseDependentType &&
1417  "cannot make statement while the promise type is dependent");
1418  assert(this->ReturnValue && "ReturnValue must be already formed");
1419 
1420  QualType const GroType = this->ReturnValue->getType();
1421  assert(!GroType->isDependentType() &&
1422  "get_return_object type must no longer be dependent");
1423 
1424  QualType const FnRetType = FD.getReturnType();
1425  assert(!FnRetType->isDependentType() &&
1426  "get_return_object type must no longer be dependent");
1427 
1428  if (FnRetType->isVoidType()) {
1429  ExprResult Res =
1430  S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
1431  if (Res.isInvalid())
1432  return false;
1433 
1434  this->ResultDecl = Res.get();
1435  return true;
1436  }
1437 
1438  if (GroType->isVoidType()) {
1439  // Trigger a nice error message.
1440  InitializedEntity Entity =
1441  InitializedEntity::InitializeResult(Loc, FnRetType, false);
1442  S.PerformMoveOrCopyInitialization(Entity, nullptr, FnRetType, ReturnValue);
1444  return false;
1445  }
1446 
1447  auto *GroDecl = VarDecl::Create(
1448  S.Context, &FD, FD.getLocation(), FD.getLocation(),
1449  &S.PP.getIdentifierTable().get("__coro_gro"), GroType,
1450  S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
1451 
1452  S.CheckVariableDeclarationType(GroDecl);
1453  if (GroDecl->isInvalidDecl())
1454  return false;
1455 
1457  ExprResult Res = S.PerformMoveOrCopyInitialization(Entity, nullptr, GroType,
1458  this->ReturnValue);
1459  if (Res.isInvalid())
1460  return false;
1461 
1462  Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
1463  if (Res.isInvalid())
1464  return false;
1465 
1466  S.AddInitializerToDecl(GroDecl, Res.get(),
1467  /*DirectInit=*/false);
1468 
1469  S.FinalizeDeclaration(GroDecl);
1470 
1471  // Form a declaration statement for the return declaration, so that AST
1472  // visitors can more easily find it.
1473  StmtResult GroDeclStmt =
1474  S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
1475  if (GroDeclStmt.isInvalid())
1476  return false;
1477 
1478  this->ResultDecl = GroDeclStmt.get();
1479 
1480  ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
1481  if (declRef.isInvalid())
1482  return false;
1483 
1484  StmtResult ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
1485  if (ReturnStmt.isInvalid()) {
1487  return false;
1488  }
1489  if (cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl)
1490  GroDecl->setNRVOVariable(true);
1491 
1492  this->ReturnStmt = ReturnStmt.get();
1493  return true;
1494 }
1495 
1496 // Create a static_cast<T&&>(expr).
1497 static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) {
1498  if (T.isNull())
1499  T = E->getType();
1500  QualType TargetType = S.BuildReferenceType(
1501  T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName());
1502  SourceLocation ExprLoc = E->getBeginLoc();
1503  TypeSourceInfo *TargetLoc =
1504  S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc);
1505 
1506  return S
1507  .BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
1508  SourceRange(ExprLoc, ExprLoc), E->getSourceRange())
1509  .get();
1510 }
1511 
1512 /// Build a variable declaration for move parameter.
1514  IdentifierInfo *II) {
1515  TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc);
1516  VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type,
1517  TInfo, SC_None);
1518  Decl->setImplicit();
1519  return Decl;
1520 }
1521 
1522 // Build statements that move coroutine function parameters to the coroutine
1523 // frame, and store them on the function scope info.
1525  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
1526  auto *FD = cast<FunctionDecl>(CurContext);
1527 
1528  auto *ScopeInfo = getCurFunction();
1529  assert(ScopeInfo->CoroutineParameterMoves.empty() &&
1530  "Should not build parameter moves twice");
1531 
1532  for (auto *PD : FD->parameters()) {
1533  if (PD->getType()->isDependentType())
1534  continue;
1535 
1536  ExprResult PDRefExpr =
1537  BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(),
1538  ExprValueKind::VK_LValue, Loc); // FIXME: scope?
1539  if (PDRefExpr.isInvalid())
1540  return false;
1541 
1542  Expr *CExpr = nullptr;
1543  if (PD->getType()->getAsCXXRecordDecl() ||
1544  PD->getType()->isRValueReferenceType())
1545  CExpr = castForMoving(*this, PDRefExpr.get());
1546  else
1547  CExpr = PDRefExpr.get();
1548 
1549  auto D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier());
1550  AddInitializerToDecl(D, CExpr, /*DirectInit=*/true);
1551 
1552  // Convert decl to a statement.
1553  StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc);
1554  if (Stmt.isInvalid())
1555  return false;
1556 
1557  ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get()));
1558  }
1559  return true;
1560 }
1561 
1563  CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args);
1564  if (!Res)
1565  return StmtError();
1566  return Res;
1567 }
1568 
1570  SourceLocation FuncLoc) {
1571  if (!StdCoroutineTraitsCache) {
1572  if (auto StdExp = lookupStdExperimentalNamespace()) {
1573  LookupResult Result(*this,
1574  &PP.getIdentifierTable().get("coroutine_traits"),
1575  FuncLoc, LookupOrdinaryName);
1576  if (!LookupQualifiedName(Result, StdExp)) {
1577  Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
1578  << "std::experimental::coroutine_traits";
1579  return nullptr;
1580  }
1581  if (!(StdCoroutineTraitsCache =
1582  Result.getAsSingle<ClassTemplateDecl>())) {
1583  Result.suppressDiagnostics();
1584  NamedDecl *Found = *Result.begin();
1585  Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits);
1586  return nullptr;
1587  }
1588  }
1589  }
1590  return StdCoroutineTraitsCache;
1591 }
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:559
Represents a function declaration or definition.
Definition: Decl.h:1784
Represents a &#39;co_await&#39; expression while the type of the promise is dependent.
Definition: ExprCXX.h:4741
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:4062
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2585
A (possibly-)qualified type.
Definition: Type.h:643
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:3315
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:66
bool isSpecificPlaceholderType(unsigned K) const
Test for a specific placeholder type.
Definition: Type.h:6637
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:1375
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:3037
Scope * TUScope
Translation Unit Scope - useful to Objective-C actions that need to lookup file scope declarations in...
Definition: Sema.h:888
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:6339
The base class of the type hierarchy.
Definition: Type.h:1436
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:458
Represent a C++ namespace.
Definition: Decl.h:522
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:15395
std::pair< Stmt *, Stmt * > CoroutineSuspends
The initial and final coroutine suspend points.
Definition: ScopeInfo.h:200
Retains information about a function, method, or block that is currently being parsed.
Definition: ScopeInfo.h:97
This file provides some common utility functions for processing Lambda related AST Constructs...
Represents a variable declaration or definition.
Definition: Decl.h:827
ActionResult< Stmt * > StmtResult
Definition: Ownership.h:264
bool isStructureType() const
Definition: Type.cpp:495
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:2365
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6858
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:5707
bool isAmbiguous() const
Definition: Lookup.h:301
bool isInvalidDecl() const
Definition: DeclBase.h:553
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:197
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:3934
bool ActOnCoroutineBodyStart(Scope *S, SourceLocation KwLoc, StringRef Keyword)
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:274
DeclGroupPtrTy ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType=nullptr)
Definition: SemaDecl.cpp:54
static FunctionDecl * findDeleteForPromise(Sema &S, SourceLocation Loc, QualType PromiseType)
bool isReferenceType() const
Definition: Type.h:6403
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Decl.h:746
IdentifierTable & Idents
Definition: ASTContext.h:579
SourceLocation FirstSEHTryLoc
First SEH &#39;__try&#39; statement in the current function.
Definition: ScopeInfo.h:174
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:125
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2325
static ParenListExpr * Create(const ASTContext &Ctx, SourceLocation LParenLoc, ArrayRef< Expr *> Exprs, SourceLocation RParenLoc)
Create a paren list.
Definition: Expr.cpp:4443
bool isCompleteType(SourceLocation Loc, QualType T)
Definition: Sema.h:1765
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...
DeclRefExpr * BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK, SourceLocation Loc, const CXXScopeSpec *SS=nullptr)
Definition: SemaExpr.cpp:1771
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:414
StmtResult StmtError()
Definition: Ownership.h:280
Represents a declaration of a type.
Definition: Decl.h:2943
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:6148
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:7556
Preprocessor & PP
Definition: Sema.h:376
static VarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S)
Definition: Decl.cpp:1965
const LangOptions & getLangOpts() const
Definition: Sema.h:1288
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:8030
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:3323
ExprResult BuildDeclarationNameExpr(const CXXScopeSpec &SS, LookupResult &R, bool NeedsADL, bool AcceptInvalidDecl=false)
Definition: SemaExpr.cpp:2906
static UnresolvedLookupExpr * Create(const ASTContext &Context, CXXRecordDecl *NamingClass, NestedNameSpecifierLoc QualifierLoc, const DeclarationNameInfo &NameInfo, bool RequiresADL, bool Overloaded, UnresolvedSetIterator Begin, UnresolvedSetIterator End)
Definition: ExprCXX.cpp:403
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:331
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:1692
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3725
StmtResult BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp)
Definition: SemaStmt.cpp:3578
StmtResult ActOnCoreturnStmt(Scope *S, SourceLocation KwLoc, Expr *E)
DeclarationNameTable DeclarationNames
Definition: ASTContext.h:582
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:11430
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:5609
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6923
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:132
Defines the clang::Preprocessor interface.
static bool isWithinCatchScope(Scope *S)
DeclContext * getDeclContext()
Definition: DeclBase.h:438
ExprResult BuildCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind, TypeSourceInfo *Ty, Expr *E, SourceRange AngleBrackets, SourceRange Parens)
Definition: SemaCast.cpp:258
static bool IsOverloaded(const UnresolvedSetImpl &Functions)
FunctionDecl * getDirectCallee()
If the callee is a FunctionDecl, return it. Otherwise return null.
Definition: Expr.h:2656
Represents a C++ template name within the type system.
Definition: TemplateName.h:187
decls_iterator decls_begin() const
Definition: ExprCXX.h:2936
bool RequireCompleteType(SourceLocation Loc, QualType T, TypeDiagnoser &Diagnoser)
Ensure that the type T is a complete type.
Definition: SemaType.cpp:7826
static bool isValidCoroutineContext(Sema &S, SourceLocation Loc, StringRef Keyword)
QualType getType() const
Definition: Expr.h:137
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:2620
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:1403
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:708
VarDecl * CoroutinePromise
The promise object for this coroutine, if any.
Definition: ScopeInfo.h:193
ExprObjectKind getObjectKind() const
getObjectKind - The object kind that this expression produces.
Definition: Expr.h:421
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:1050
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:3651
void FinalizeDeclaration(Decl *D)
FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform any semantic actions neces...
Definition: SemaDecl.cpp:12634
FunctionDecl * FindUsualDeallocationFunction(SourceLocation StartLoc, bool CanProvideSize, bool Overaligned, DeclarationName Name)
IdentifierTable & getIdentifierTable()
Definition: Preprocessor.h:911
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:1905
Only look for allocation functions in the scope of the allocated class.
Definition: Sema.h:5587
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:165
QualType BuildReferenceType(QualType T, bool LValueRef, SourceLocation Loc, DeclarationName Entity)
Build a reference type.
Definition: SemaType.cpp:2032
An rvalue ref-qualifier was provided (&&).
Definition: Type.h:1395
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:221
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:6624
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:1271
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:4792
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:6767
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:1496
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:11570
static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType, SourceLocation Loc)
SourceLocation FirstReturnLoc
First &#39;return&#39; statement in the current function.
Definition: ScopeInfo.h:168
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:5590
CanQualType DependentTy
Definition: ASTContext.h:1044
Represents a &#39;co_await&#39; expression.
Definition: ExprCXX.h:4705
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:13450
ExprResult ActOnCoyieldExpr(Scope *S, SourceLocation KwLoc, Expr *E)
bool isClassType() const
Definition: Type.cpp:489
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:835
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:3121
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:5584
Represents a C++ struct/union/class.
Definition: DeclCXX.h:255
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:6650
sema::FunctionScopeInfo * getCurFunction() const
Definition: Sema.h:1452
Builtin::Context & BuiltinInfo
Definition: ASTContext.h:581
DeclContext * CurContext
CurContext - This is the current declaration context of parsing.
Definition: Sema.h:389
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:262
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2521
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:2121
bool hasInvalidCoroutineSuspends() const
Definition: ScopeInfo.h:476
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:655
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:129
A trivial tuple used to represent a source range.
ASTContext & Context
Definition: Sema.h:377
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:5147
Describes an entity that is being initialized.
Look up of an operator name (e.g., operator+) for use with operator overloading.
Definition: Sema.h:3327
NamedDecl * getRepresentativeDecl() const
Fetches a representative decl. Useful for lazy diagnostics.
Definition: Lookup.h:524
Decl * getCalleeDecl()
Definition: Expr.h:2650
decls_iterator decls_end() const
Definition: ExprCXX.h:2939
static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD, SourceLocation Loc, bool &Res)
SourceLocation getLocation() const
Definition: DeclBase.h:429
LangStandard::Kind Std
VarDecl * buildCoroutinePromise(SourceLocation Loc)
static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn)