clang  8.0.0
SemaCoroutine.cpp
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1 //===--- SemaCoroutines.cpp - Semantic Analysis for Coroutines ------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements semantic analysis for C++ Coroutines.
11 //
12 // This file contains references to sections of the Coroutines TS, which
13 // can be found at http://wg21.link/coroutines.
14 //
15 //===----------------------------------------------------------------------===//
16 
17 #include "CoroutineStmtBuilder.h"
18 #include "clang/AST/ASTLambda.h"
19 #include "clang/AST/Decl.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/StmtCXX.h"
22 #include "clang/Lex/Preprocessor.h"
24 #include "clang/Sema/Overload.h"
25 #include "clang/Sema/ScopeInfo.h"
27 
28 using namespace clang;
29 using namespace sema;
30 
31 static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
32  SourceLocation Loc, bool &Res) {
34  LookupResult LR(S, DN, Loc, Sema::LookupMemberName);
35  // Suppress diagnostics when a private member is selected. The same warnings
36  // will be produced again when building the call.
38  Res = S.LookupQualifiedName(LR, RD);
39  return LR;
40 }
41 
42 static bool lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
43  SourceLocation Loc) {
44  bool Res;
45  lookupMember(S, Name, RD, Loc, Res);
46  return Res;
47 }
48 
49 /// Look up the std::coroutine_traits<...>::promise_type for the given
50 /// function type.
52  SourceLocation KwLoc) {
53  const FunctionProtoType *FnType = FD->getType()->castAs<FunctionProtoType>();
54  const SourceLocation FuncLoc = FD->getLocation();
55  // FIXME: Cache std::coroutine_traits once we've found it.
57  if (!StdExp) {
58  S.Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
59  << "std::experimental::coroutine_traits";
60  return QualType();
61  }
62 
63  ClassTemplateDecl *CoroTraits = S.lookupCoroutineTraits(KwLoc, FuncLoc);
64  if (!CoroTraits) {
65  return QualType();
66  }
67 
68  // Form template argument list for coroutine_traits<R, P1, P2, ...> according
69  // to [dcl.fct.def.coroutine]3
70  TemplateArgumentListInfo Args(KwLoc, KwLoc);
71  auto AddArg = [&](QualType T) {
74  };
75  AddArg(FnType->getReturnType());
76  // If the function is a non-static member function, add the type
77  // of the implicit object parameter before the formal parameters.
78  if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
79  if (MD->isInstance()) {
80  // [over.match.funcs]4
81  // For non-static member functions, the type of the implicit object
82  // parameter is
83  // -- "lvalue reference to cv X" for functions declared without a
84  // ref-qualifier or with the & ref-qualifier
85  // -- "rvalue reference to cv X" for functions declared with the &&
86  // ref-qualifier
87  QualType T = MD->getThisType()->getAs<PointerType>()->getPointeeType();
88  T = FnType->getRefQualifier() == RQ_RValue
90  : S.Context.getLValueReferenceType(T, /*SpelledAsLValue*/ true);
91  AddArg(T);
92  }
93  }
94  for (QualType T : FnType->getParamTypes())
95  AddArg(T);
96 
97  // Build the template-id.
98  QualType CoroTrait =
99  S.CheckTemplateIdType(TemplateName(CoroTraits), KwLoc, Args);
100  if (CoroTrait.isNull())
101  return QualType();
102  if (S.RequireCompleteType(KwLoc, CoroTrait,
103  diag::err_coroutine_type_missing_specialization))
104  return QualType();
105 
106  auto *RD = CoroTrait->getAsCXXRecordDecl();
107  assert(RD && "specialization of class template is not a class?");
108 
109  // Look up the ::promise_type member.
110  LookupResult R(S, &S.PP.getIdentifierTable().get("promise_type"), KwLoc,
112  S.LookupQualifiedName(R, RD);
113  auto *Promise = R.getAsSingle<TypeDecl>();
114  if (!Promise) {
115  S.Diag(FuncLoc,
116  diag::err_implied_std_coroutine_traits_promise_type_not_found)
117  << RD;
118  return QualType();
119  }
120  // The promise type is required to be a class type.
121  QualType PromiseType = S.Context.getTypeDeclType(Promise);
122 
123  auto buildElaboratedType = [&]() {
124  auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, StdExp);
125  NNS = NestedNameSpecifier::Create(S.Context, NNS, false,
126  CoroTrait.getTypePtr());
127  return S.Context.getElaboratedType(ETK_None, NNS, PromiseType);
128  };
129 
130  if (!PromiseType->getAsCXXRecordDecl()) {
131  S.Diag(FuncLoc,
132  diag::err_implied_std_coroutine_traits_promise_type_not_class)
133  << buildElaboratedType();
134  return QualType();
135  }
136  if (S.RequireCompleteType(FuncLoc, buildElaboratedType(),
137  diag::err_coroutine_promise_type_incomplete))
138  return QualType();
139 
140  return PromiseType;
141 }
142 
143 /// Look up the std::experimental::coroutine_handle<PromiseType>.
145  SourceLocation Loc) {
146  if (PromiseType.isNull())
147  return QualType();
148 
150  assert(StdExp && "Should already be diagnosed");
151 
152  LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_handle"),
154  if (!S.LookupQualifiedName(Result, StdExp)) {
155  S.Diag(Loc, diag::err_implied_coroutine_type_not_found)
156  << "std::experimental::coroutine_handle";
157  return QualType();
158  }
159 
160  ClassTemplateDecl *CoroHandle = Result.getAsSingle<ClassTemplateDecl>();
161  if (!CoroHandle) {
162  Result.suppressDiagnostics();
163  // We found something weird. Complain about the first thing we found.
164  NamedDecl *Found = *Result.begin();
165  S.Diag(Found->getLocation(), diag::err_malformed_std_coroutine_handle);
166  return QualType();
167  }
168 
169  // Form template argument list for coroutine_handle<Promise>.
170  TemplateArgumentListInfo Args(Loc, Loc);
172  TemplateArgument(PromiseType),
173  S.Context.getTrivialTypeSourceInfo(PromiseType, Loc)));
174 
175  // Build the template-id.
176  QualType CoroHandleType =
177  S.CheckTemplateIdType(TemplateName(CoroHandle), Loc, Args);
178  if (CoroHandleType.isNull())
179  return QualType();
180  if (S.RequireCompleteType(Loc, CoroHandleType,
181  diag::err_coroutine_type_missing_specialization))
182  return QualType();
183 
184  return CoroHandleType;
185 }
186 
188  StringRef Keyword) {
189  // 'co_await' and 'co_yield' are not permitted in unevaluated operands,
190  // such as subexpressions of \c sizeof.
191  //
192  // [expr.await]p2, emphasis added: "An await-expression shall appear only in
193  // a *potentially evaluated* expression within the compound-statement of a
194  // function-body outside of a handler [...] A context within a function where
195  // an await-expression can appear is called a suspension context of the
196  // function." And per [expr.yield]p1: "A yield-expression shall appear only
197  // within a suspension context of a function."
198  if (S.isUnevaluatedContext()) {
199  S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
200  return false;
201  }
202 
203  // Per [expr.await]p2, any other usage must be within a function.
204  // FIXME: This also covers [expr.await]p2: "An await-expression shall not
205  // appear in a default argument." But the diagnostic QoI here could be
206  // improved to inform the user that default arguments specifically are not
207  // allowed.
208  auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
209  if (!FD) {
210  S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
211  ? diag::err_coroutine_objc_method
212  : diag::err_coroutine_outside_function) << Keyword;
213  return false;
214  }
215 
216  // An enumeration for mapping the diagnostic type to the correct diagnostic
217  // selection index.
218  enum InvalidFuncDiag {
219  DiagCtor = 0,
220  DiagDtor,
221  DiagCopyAssign,
222  DiagMoveAssign,
223  DiagMain,
224  DiagConstexpr,
225  DiagAutoRet,
226  DiagVarargs,
227  };
228  bool Diagnosed = false;
229  auto DiagInvalid = [&](InvalidFuncDiag ID) {
230  S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
231  Diagnosed = true;
232  return false;
233  };
234 
235  // Diagnose when a constructor, destructor, copy/move assignment operator,
236  // or the function 'main' are declared as a coroutine.
237  auto *MD = dyn_cast<CXXMethodDecl>(FD);
238  // [class.ctor]p6: "A constructor shall not be a coroutine."
239  if (MD && isa<CXXConstructorDecl>(MD))
240  return DiagInvalid(DiagCtor);
241  // [class.dtor]p17: "A destructor shall not be a coroutine."
242  else if (MD && isa<CXXDestructorDecl>(MD))
243  return DiagInvalid(DiagDtor);
244  // N4499 [special]p6: "A special member function shall not be a coroutine."
245  // Per C++ [special]p1, special member functions are the "default constructor,
246  // copy constructor and copy assignment operator, move constructor and move
247  // assignment operator, and destructor."
248  else if (MD && MD->isCopyAssignmentOperator())
249  return DiagInvalid(DiagCopyAssign);
250  else if (MD && MD->isMoveAssignmentOperator())
251  return DiagInvalid(DiagMoveAssign);
252  // [basic.start.main]p3: "The function main shall not be a coroutine."
253  else if (FD->isMain())
254  return DiagInvalid(DiagMain);
255 
256  // Emit a diagnostics for each of the following conditions which is not met.
257  // [expr.const]p2: "An expression e is a core constant expression unless the
258  // evaluation of e [...] would evaluate one of the following expressions:
259  // [...] an await-expression [...] a yield-expression."
260  if (FD->isConstexpr())
261  DiagInvalid(DiagConstexpr);
262  // [dcl.spec.auto]p15: "A function declared with a return type that uses a
263  // placeholder type shall not be a coroutine."
264  if (FD->getReturnType()->isUndeducedType())
265  DiagInvalid(DiagAutoRet);
266  // [dcl.fct.def.coroutine]p1: "The parameter-declaration-clause of the
267  // coroutine shall not terminate with an ellipsis that is not part of a
268  // parameter-declaration."
269  if (FD->isVariadic())
270  DiagInvalid(DiagVarargs);
271 
272  return !Diagnosed;
273 }
274 
276  SourceLocation Loc) {
277  DeclarationName OpName =
278  SemaRef.Context.DeclarationNames.getCXXOperatorName(OO_Coawait);
279  LookupResult Operators(SemaRef, OpName, SourceLocation(),
281  SemaRef.LookupName(Operators, S);
282 
283  assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
284  const auto &Functions = Operators.asUnresolvedSet();
285  bool IsOverloaded =
286  Functions.size() > 1 ||
287  (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
288  Expr *CoawaitOp = UnresolvedLookupExpr::Create(
289  SemaRef.Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(),
290  DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded,
291  Functions.begin(), Functions.end());
292  assert(CoawaitOp);
293  return CoawaitOp;
294 }
295 
296 /// Build a call to 'operator co_await' if there is a suitable operator for
297 /// the given expression.
299  Expr *E,
300  UnresolvedLookupExpr *Lookup) {
301  UnresolvedSet<16> Functions;
302  Functions.append(Lookup->decls_begin(), Lookup->decls_end());
303  return SemaRef.CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E);
304 }
305 
307  SourceLocation Loc, Expr *E) {
308  ExprResult R = buildOperatorCoawaitLookupExpr(SemaRef, S, Loc);
309  if (R.isInvalid())
310  return ExprError();
311  return buildOperatorCoawaitCall(SemaRef, Loc, E,
312  cast<UnresolvedLookupExpr>(R.get()));
313 }
314 
316  MultiExprArg CallArgs) {
317  StringRef Name = S.Context.BuiltinInfo.getName(Id);
319  S.LookupName(R, S.TUScope, /*AllowBuiltinCreation=*/true);
320 
321  auto *BuiltInDecl = R.getAsSingle<FunctionDecl>();
322  assert(BuiltInDecl && "failed to find builtin declaration");
323 
324  ExprResult DeclRef =
325  S.BuildDeclRefExpr(BuiltInDecl, BuiltInDecl->getType(), VK_LValue, Loc);
326  assert(DeclRef.isUsable() && "Builtin reference cannot fail");
327 
328  ExprResult Call =
329  S.ActOnCallExpr(/*Scope=*/nullptr, DeclRef.get(), Loc, CallArgs, Loc);
330 
331  assert(!Call.isInvalid() && "Call to builtin cannot fail!");
332  return Call.get();
333 }
334 
336  SourceLocation Loc) {
337  QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
338  if (CoroHandleType.isNull())
339  return ExprError();
340 
341  DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType);
342  LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc,
344  if (!S.LookupQualifiedName(Found, LookupCtx)) {
345  S.Diag(Loc, diag::err_coroutine_handle_missing_member)
346  << "from_address";
347  return ExprError();
348  }
349 
350  Expr *FramePtr =
351  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
352 
353  CXXScopeSpec SS;
354  ExprResult FromAddr =
355  S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
356  if (FromAddr.isInvalid())
357  return ExprError();
358 
359  return S.ActOnCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc);
360 }
361 
363  enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
364  Expr *Results[3];
366  bool IsInvalid;
367 };
368 
370  StringRef Name, MultiExprArg Args) {
371  DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc);
372 
373  // FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&.
374  CXXScopeSpec SS;
376  Base, Base->getType(), Loc, /*IsPtr=*/false, SS,
377  SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr,
378  /*Scope=*/nullptr);
379  if (Result.isInvalid())
380  return ExprError();
381 
382  // We meant exactly what we asked for. No need for typo correction.
383  if (auto *TE = dyn_cast<TypoExpr>(Result.get())) {
384  S.clearDelayedTypo(TE);
385  S.Diag(Loc, diag::err_no_member)
386  << NameInfo.getName() << Base->getType()->getAsCXXRecordDecl()
387  << Base->getSourceRange();
388  return ExprError();
389  }
390 
391  return S.ActOnCallExpr(nullptr, Result.get(), Loc, Args, Loc, nullptr);
392 }
393 
394 // See if return type is coroutine-handle and if so, invoke builtin coro-resume
395 // on its address. This is to enable experimental support for coroutine-handle
396 // returning await_suspend that results in a guaranteed tail call to the target
397 // coroutine.
398 static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
399  SourceLocation Loc) {
400  if (RetType->isReferenceType())
401  return nullptr;
402  Type const *T = RetType.getTypePtr();
403  if (!T->isClassType() && !T->isStructureType())
404  return nullptr;
405 
406  // FIXME: Add convertability check to coroutine_handle<>. Possibly via
407  // EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment
408  // a private function in SemaExprCXX.cpp
409 
410  ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", None);
411  if (AddressExpr.isInvalid())
412  return nullptr;
413 
414  Expr *JustAddress = AddressExpr.get();
415  // FIXME: Check that the type of AddressExpr is void*
416  return buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_resume,
417  JustAddress);
418 }
419 
420 /// Build calls to await_ready, await_suspend, and await_resume for a co_await
421 /// expression.
423  SourceLocation Loc, Expr *E) {
424  OpaqueValueExpr *Operand = new (S.Context)
425  OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
426 
427  // Assume invalid until we see otherwise.
428  ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/true};
429 
430  ExprResult CoroHandleRes = buildCoroutineHandle(S, CoroPromise->getType(), Loc);
431  if (CoroHandleRes.isInvalid())
432  return Calls;
433  Expr *CoroHandle = CoroHandleRes.get();
434 
435  const StringRef Funcs[] = {"await_ready", "await_suspend", "await_resume"};
436  MultiExprArg Args[] = {None, CoroHandle, None};
437  for (size_t I = 0, N = llvm::array_lengthof(Funcs); I != N; ++I) {
438  ExprResult Result = buildMemberCall(S, Operand, Loc, Funcs[I], Args[I]);
439  if (Result.isInvalid())
440  return Calls;
441  Calls.Results[I] = Result.get();
442  }
443 
444  // Assume the calls are valid; all further checking should make them invalid.
445  Calls.IsInvalid = false;
446 
448  CallExpr *AwaitReady = cast<CallExpr>(Calls.Results[ACT::ACT_Ready]);
449  if (!AwaitReady->getType()->isDependentType()) {
450  // [expr.await]p3 [...]
451  // — await-ready is the expression e.await_ready(), contextually converted
452  // to bool.
453  ExprResult Conv = S.PerformContextuallyConvertToBool(AwaitReady);
454  if (Conv.isInvalid()) {
455  S.Diag(AwaitReady->getDirectCallee()->getBeginLoc(),
456  diag::note_await_ready_no_bool_conversion);
457  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
458  << AwaitReady->getDirectCallee() << E->getSourceRange();
459  Calls.IsInvalid = true;
460  }
461  Calls.Results[ACT::ACT_Ready] = Conv.get();
462  }
463  CallExpr *AwaitSuspend = cast<CallExpr>(Calls.Results[ACT::ACT_Suspend]);
464  if (!AwaitSuspend->getType()->isDependentType()) {
465  // [expr.await]p3 [...]
466  // - await-suspend is the expression e.await_suspend(h), which shall be
467  // a prvalue of type void or bool.
468  QualType RetType = AwaitSuspend->getCallReturnType(S.Context);
469 
470  // Experimental support for coroutine_handle returning await_suspend.
471  if (Expr *TailCallSuspend = maybeTailCall(S, RetType, AwaitSuspend, Loc))
472  Calls.Results[ACT::ACT_Suspend] = TailCallSuspend;
473  else {
474  // non-class prvalues always have cv-unqualified types
475  if (RetType->isReferenceType() ||
476  (!RetType->isBooleanType() && !RetType->isVoidType())) {
477  S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(),
478  diag::err_await_suspend_invalid_return_type)
479  << RetType;
480  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
481  << AwaitSuspend->getDirectCallee();
482  Calls.IsInvalid = true;
483  }
484  }
485  }
486 
487  return Calls;
488 }
489 
491  SourceLocation Loc, StringRef Name,
492  MultiExprArg Args) {
493 
494  // Form a reference to the promise.
495  ExprResult PromiseRef = S.BuildDeclRefExpr(
496  Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc);
497  if (PromiseRef.isInvalid())
498  return ExprError();
499 
500  return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
501 }
502 
504  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
505  auto *FD = cast<FunctionDecl>(CurContext);
506  bool IsThisDependentType = [&] {
507  if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
508  return MD->isInstance() && MD->getThisType()->isDependentType();
509  else
510  return false;
511  }();
512 
513  QualType T = FD->getType()->isDependentType() || IsThisDependentType
514  ? Context.DependentTy
515  : lookupPromiseType(*this, FD, Loc);
516  if (T.isNull())
517  return nullptr;
518 
519  auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(),
520  &PP.getIdentifierTable().get("__promise"), T,
521  Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
522  CheckVariableDeclarationType(VD);
523  if (VD->isInvalidDecl())
524  return nullptr;
525 
526  auto *ScopeInfo = getCurFunction();
527  // Build a list of arguments, based on the coroutine functions arguments,
528  // that will be passed to the promise type's constructor.
529  llvm::SmallVector<Expr *, 4> CtorArgExprs;
530 
531  // Add implicit object parameter.
532  if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
533  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
534  ExprResult ThisExpr = ActOnCXXThis(Loc);
535  if (ThisExpr.isInvalid())
536  return nullptr;
537  ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
538  if (ThisExpr.isInvalid())
539  return nullptr;
540  CtorArgExprs.push_back(ThisExpr.get());
541  }
542  }
543 
544  auto &Moves = ScopeInfo->CoroutineParameterMoves;
545  for (auto *PD : FD->parameters()) {
546  if (PD->getType()->isDependentType())
547  continue;
548 
549  auto RefExpr = ExprEmpty();
550  auto Move = Moves.find(PD);
551  assert(Move != Moves.end() &&
552  "Coroutine function parameter not inserted into move map");
553  // If a reference to the function parameter exists in the coroutine
554  // frame, use that reference.
555  auto *MoveDecl =
556  cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl());
557  RefExpr =
558  BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(),
559  ExprValueKind::VK_LValue, FD->getLocation());
560  if (RefExpr.isInvalid())
561  return nullptr;
562  CtorArgExprs.push_back(RefExpr.get());
563  }
564 
565  // Create an initialization sequence for the promise type using the
566  // constructor arguments, wrapped in a parenthesized list expression.
567  Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(),
568  CtorArgExprs, FD->getLocation());
571  VD->getLocation(), /*DirectInit=*/true, PLE);
572  InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs,
573  /*TopLevelOfInitList=*/false,
574  /*TreatUnavailableAsInvalid=*/false);
575 
576  // Attempt to initialize the promise type with the arguments.
577  // If that fails, fall back to the promise type's default constructor.
578  if (InitSeq) {
579  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs);
580  if (Result.isInvalid()) {
581  VD->setInvalidDecl();
582  } else if (Result.get()) {
583  VD->setInit(MaybeCreateExprWithCleanups(Result.get()));
584  VD->setInitStyle(VarDecl::CallInit);
585  CheckCompleteVariableDeclaration(VD);
586  }
587  } else
588  ActOnUninitializedDecl(VD);
589 
590  FD->addDecl(VD);
591  return VD;
592 }
593 
594 /// Check that this is a context in which a coroutine suspension can appear.
596  StringRef Keyword,
597  bool IsImplicit = false) {
598  if (!isValidCoroutineContext(S, Loc, Keyword))
599  return nullptr;
600 
601  assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope");
602 
603  auto *ScopeInfo = S.getCurFunction();
604  assert(ScopeInfo && "missing function scope for function");
605 
606  if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit)
607  ScopeInfo->setFirstCoroutineStmt(Loc, Keyword);
608 
609  if (ScopeInfo->CoroutinePromise)
610  return ScopeInfo;
611 
612  if (!S.buildCoroutineParameterMoves(Loc))
613  return nullptr;
614 
615  ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc);
616  if (!ScopeInfo->CoroutinePromise)
617  return nullptr;
618 
619  return ScopeInfo;
620 }
621 
623  StringRef Keyword) {
624  if (!checkCoroutineContext(*this, KWLoc, Keyword))
625  return false;
626  auto *ScopeInfo = getCurFunction();
627  assert(ScopeInfo->CoroutinePromise);
628 
629  // If we have existing coroutine statements then we have already built
630  // the initial and final suspend points.
631  if (!ScopeInfo->NeedsCoroutineSuspends)
632  return true;
633 
634  ScopeInfo->setNeedsCoroutineSuspends(false);
635 
636  auto *Fn = cast<FunctionDecl>(CurContext);
637  SourceLocation Loc = Fn->getLocation();
638  // Build the initial suspend point
639  auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
640  ExprResult Suspend =
641  buildPromiseCall(*this, ScopeInfo->CoroutinePromise, Loc, Name, None);
642  if (Suspend.isInvalid())
643  return StmtError();
644  Suspend = buildOperatorCoawaitCall(*this, SC, Loc, Suspend.get());
645  if (Suspend.isInvalid())
646  return StmtError();
647  Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),
648  /*IsImplicit*/ true);
649  Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
650  if (Suspend.isInvalid()) {
651  Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
652  << ((Name == "initial_suspend") ? 0 : 1);
653  Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
654  return StmtError();
655  }
656  return cast<Stmt>(Suspend.get());
657  };
658 
659  StmtResult InitSuspend = buildSuspends("initial_suspend");
660  if (InitSuspend.isInvalid())
661  return true;
662 
663  StmtResult FinalSuspend = buildSuspends("final_suspend");
664  if (FinalSuspend.isInvalid())
665  return true;
666 
667  ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());
668 
669  return true;
670 }
671 
673  if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) {
674  CorrectDelayedTyposInExpr(E);
675  return ExprError();
676  }
677 
678  if (E->getType()->isPlaceholderType()) {
679  ExprResult R = CheckPlaceholderExpr(E);
680  if (R.isInvalid()) return ExprError();
681  E = R.get();
682  }
683  ExprResult Lookup = buildOperatorCoawaitLookupExpr(*this, S, Loc);
684  if (Lookup.isInvalid())
685  return ExprError();
686  return BuildUnresolvedCoawaitExpr(Loc, E,
687  cast<UnresolvedLookupExpr>(Lookup.get()));
688 }
689 
691  UnresolvedLookupExpr *Lookup) {
692  auto *FSI = checkCoroutineContext(*this, Loc, "co_await");
693  if (!FSI)
694  return ExprError();
695 
696  if (E->getType()->isPlaceholderType()) {
697  ExprResult R = CheckPlaceholderExpr(E);
698  if (R.isInvalid())
699  return ExprError();
700  E = R.get();
701  }
702 
703  auto *Promise = FSI->CoroutinePromise;
704  if (Promise->getType()->isDependentType()) {
705  Expr *Res =
706  new (Context) DependentCoawaitExpr(Loc, Context.DependentTy, E, Lookup);
707  return Res;
708  }
709 
710  auto *RD = Promise->getType()->getAsCXXRecordDecl();
711  if (lookupMember(*this, "await_transform", RD, Loc)) {
712  ExprResult R = buildPromiseCall(*this, Promise, Loc, "await_transform", E);
713  if (R.isInvalid()) {
714  Diag(Loc,
715  diag::note_coroutine_promise_implicit_await_transform_required_here)
716  << E->getSourceRange();
717  return ExprError();
718  }
719  E = R.get();
720  }
721  ExprResult Awaitable = buildOperatorCoawaitCall(*this, Loc, E, Lookup);
722  if (Awaitable.isInvalid())
723  return ExprError();
724 
725  return BuildResolvedCoawaitExpr(Loc, Awaitable.get());
726 }
727 
729  bool IsImplicit) {
730  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit);
731  if (!Coroutine)
732  return ExprError();
733 
734  if (E->getType()->isPlaceholderType()) {
735  ExprResult R = CheckPlaceholderExpr(E);
736  if (R.isInvalid()) return ExprError();
737  E = R.get();
738  }
739 
740  if (E->getType()->isDependentType()) {
741  Expr *Res = new (Context)
742  CoawaitExpr(Loc, Context.DependentTy, E, IsImplicit);
743  return Res;
744  }
745 
746  // If the expression is a temporary, materialize it as an lvalue so that we
747  // can use it multiple times.
748  if (E->getValueKind() == VK_RValue)
749  E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
750 
751  // The location of the `co_await` token cannot be used when constructing
752  // the member call expressions since it's before the location of `Expr`, which
753  // is used as the start of the member call expression.
754  SourceLocation CallLoc = E->getExprLoc();
755 
756  // Build the await_ready, await_suspend, await_resume calls.
758  buildCoawaitCalls(*this, Coroutine->CoroutinePromise, CallLoc, E);
759  if (RSS.IsInvalid)
760  return ExprError();
761 
762  Expr *Res =
763  new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
764  RSS.Results[2], RSS.OpaqueValue, IsImplicit);
765 
766  return Res;
767 }
768 
770  if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) {
771  CorrectDelayedTyposInExpr(E);
772  return ExprError();
773  }
774 
775  // Build yield_value call.
776  ExprResult Awaitable = buildPromiseCall(
777  *this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E);
778  if (Awaitable.isInvalid())
779  return ExprError();
780 
781  // Build 'operator co_await' call.
782  Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get());
783  if (Awaitable.isInvalid())
784  return ExprError();
785 
786  return BuildCoyieldExpr(Loc, Awaitable.get());
787 }
789  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
790  if (!Coroutine)
791  return ExprError();
792 
793  if (E->getType()->isPlaceholderType()) {
794  ExprResult R = CheckPlaceholderExpr(E);
795  if (R.isInvalid()) return ExprError();
796  E = R.get();
797  }
798 
799  if (E->getType()->isDependentType()) {
800  Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, E);
801  return Res;
802  }
803 
804  // If the expression is a temporary, materialize it as an lvalue so that we
805  // can use it multiple times.
806  if (E->getValueKind() == VK_RValue)
807  E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
808 
809  // Build the await_ready, await_suspend, await_resume calls.
811  buildCoawaitCalls(*this, Coroutine->CoroutinePromise, Loc, E);
812  if (RSS.IsInvalid)
813  return ExprError();
814 
815  Expr *Res =
816  new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
817  RSS.Results[2], RSS.OpaqueValue);
818 
819  return Res;
820 }
821 
823  if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) {
824  CorrectDelayedTyposInExpr(E);
825  return StmtError();
826  }
827  return BuildCoreturnStmt(Loc, E);
828 }
829 
831  bool IsImplicit) {
832  auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit);
833  if (!FSI)
834  return StmtError();
835 
836  if (E && E->getType()->isPlaceholderType() &&
837  !E->getType()->isSpecificPlaceholderType(BuiltinType::Overload)) {
838  ExprResult R = CheckPlaceholderExpr(E);
839  if (R.isInvalid()) return StmtError();
840  E = R.get();
841  }
842 
843  // Move the return value if we can
844  if (E) {
845  auto NRVOCandidate = this->getCopyElisionCandidate(E->getType(), E, CES_AsIfByStdMove);
846  if (NRVOCandidate) {
847  InitializedEntity Entity =
848  InitializedEntity::InitializeResult(Loc, E->getType(), NRVOCandidate);
849  ExprResult MoveResult = this->PerformMoveOrCopyInitialization(
850  Entity, NRVOCandidate, E->getType(), E);
851  if (MoveResult.get())
852  E = MoveResult.get();
853  }
854  }
855 
856  // FIXME: If the operand is a reference to a variable that's about to go out
857  // of scope, we should treat the operand as an xvalue for this overload
858  // resolution.
859  VarDecl *Promise = FSI->CoroutinePromise;
860  ExprResult PC;
861  if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
862  PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
863  } else {
864  E = MakeFullDiscardedValueExpr(E).get();
865  PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
866  }
867  if (PC.isInvalid())
868  return StmtError();
869 
870  Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
871 
872  Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
873  return Res;
874 }
875 
876 /// Look up the std::nothrow object.
879  assert(Std && "Should already be diagnosed");
880 
881  LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
883  if (!S.LookupQualifiedName(Result, Std)) {
884  // FIXME: <experimental/coroutine> should have been included already.
885  // If we require it to include <new> then this diagnostic is no longer
886  // needed.
887  S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
888  return nullptr;
889  }
890 
891  auto *VD = Result.getAsSingle<VarDecl>();
892  if (!VD) {
893  Result.suppressDiagnostics();
894  // We found something weird. Complain about the first thing we found.
895  NamedDecl *Found = *Result.begin();
896  S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
897  return nullptr;
898  }
899 
900  ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
901  if (DR.isInvalid())
902  return nullptr;
903 
904  return DR.get();
905 }
906 
907 // Find an appropriate delete for the promise.
909  QualType PromiseType) {
910  FunctionDecl *OperatorDelete = nullptr;
911 
912  DeclarationName DeleteName =
914 
915  auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
916  assert(PointeeRD && "PromiseType must be a CxxRecordDecl type");
917 
918  if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete))
919  return nullptr;
920 
921  if (!OperatorDelete) {
922  // Look for a global declaration.
923  const bool CanProvideSize = S.isCompleteType(Loc, PromiseType);
924  const bool Overaligned = false;
925  OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
926  Overaligned, DeleteName);
927  }
928  S.MarkFunctionReferenced(Loc, OperatorDelete);
929  return OperatorDelete;
930 }
931 
932 
934  FunctionScopeInfo *Fn = getCurFunction();
935  assert(Fn && Fn->isCoroutine() && "not a coroutine");
936  if (!Body) {
937  assert(FD->isInvalidDecl() &&
938  "a null body is only allowed for invalid declarations");
939  return;
940  }
941  // We have a function that uses coroutine keywords, but we failed to build
942  // the promise type.
943  if (!Fn->CoroutinePromise)
944  return FD->setInvalidDecl();
945 
946  if (isa<CoroutineBodyStmt>(Body)) {
947  // Nothing todo. the body is already a transformed coroutine body statement.
948  return;
949  }
950 
951  // Coroutines [stmt.return]p1:
952  // A return statement shall not appear in a coroutine.
953  if (Fn->FirstReturnLoc.isValid()) {
954  assert(Fn->FirstCoroutineStmtLoc.isValid() &&
955  "first coroutine location not set");
956  Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
957  Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
959  }
960  CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body);
961  if (Builder.isInvalid() || !Builder.buildStatements())
962  return FD->setInvalidDecl();
963 
964  // Build body for the coroutine wrapper statement.
965  Body = CoroutineBodyStmt::Create(Context, Builder);
966 }
967 
970  Stmt *Body)
971  : S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()),
972  IsPromiseDependentType(
973  !Fn.CoroutinePromise ||
974  Fn.CoroutinePromise->getType()->isDependentType()) {
975  this->Body = Body;
976 
977  for (auto KV : Fn.CoroutineParameterMoves)
978  this->ParamMovesVector.push_back(KV.second);
979  this->ParamMoves = this->ParamMovesVector;
980 
981  if (!IsPromiseDependentType) {
982  PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl();
983  assert(PromiseRecordDecl && "Type should have already been checked");
984  }
985  this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend();
986 }
987 
989  assert(this->IsValid && "coroutine already invalid");
990  this->IsValid = makeReturnObject();
991  if (this->IsValid && !IsPromiseDependentType)
993  return this->IsValid;
994 }
995 
997  assert(this->IsValid && "coroutine already invalid");
998  assert(!this->IsPromiseDependentType &&
999  "coroutine cannot have a dependent promise type");
1000  this->IsValid = makeOnException() && makeOnFallthrough() &&
1001  makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
1002  makeNewAndDeleteExpr();
1003  return this->IsValid;
1004 }
1005 
1006 bool CoroutineStmtBuilder::makePromiseStmt() {
1007  // Form a declaration statement for the promise declaration, so that AST
1008  // visitors can more easily find it.
1009  StmtResult PromiseStmt =
1011  if (PromiseStmt.isInvalid())
1012  return false;
1013 
1014  this->Promise = PromiseStmt.get();
1015  return true;
1016 }
1017 
1018 bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() {
1019  if (Fn.hasInvalidCoroutineSuspends())
1020  return false;
1021  this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first);
1022  this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second);
1023  return true;
1024 }
1025 
1027  CXXRecordDecl *PromiseRecordDecl,
1028  FunctionScopeInfo &Fn) {
1029  auto Loc = E->getExprLoc();
1030  if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) {
1031  auto *Decl = DeclRef->getDecl();
1032  if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) {
1033  if (Method->isStatic())
1034  return true;
1035  else
1036  Loc = Decl->getLocation();
1037  }
1038  }
1039 
1040  S.Diag(
1041  Loc,
1042  diag::err_coroutine_promise_get_return_object_on_allocation_failure)
1043  << PromiseRecordDecl;
1044  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1046  return false;
1047 }
1048 
1049 bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
1050  assert(!IsPromiseDependentType &&
1051  "cannot make statement while the promise type is dependent");
1052 
1053  // [dcl.fct.def.coroutine]/8
1054  // The unqualified-id get_return_object_on_allocation_failure is looked up in
1055  // the scope of class P by class member access lookup (3.4.5). ...
1056  // If an allocation function returns nullptr, ... the coroutine return value
1057  // is obtained by a call to ... get_return_object_on_allocation_failure().
1058 
1059  DeclarationName DN =
1060  S.PP.getIdentifierInfo("get_return_object_on_allocation_failure");
1061  LookupResult Found(S, DN, Loc, Sema::LookupMemberName);
1062  if (!S.LookupQualifiedName(Found, PromiseRecordDecl))
1063  return true;
1064 
1065  CXXScopeSpec SS;
1066  ExprResult DeclNameExpr =
1067  S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
1068  if (DeclNameExpr.isInvalid())
1069  return false;
1070 
1071  if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn))
1072  return false;
1073 
1074  ExprResult ReturnObjectOnAllocationFailure =
1075  S.ActOnCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc);
1076  if (ReturnObjectOnAllocationFailure.isInvalid())
1077  return false;
1078 
1080  S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
1081  if (ReturnStmt.isInvalid()) {
1082  S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here)
1083  << DN;
1084  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1086  return false;
1087  }
1088 
1089  this->ReturnStmtOnAllocFailure = ReturnStmt.get();
1090  return true;
1091 }
1092 
1093 bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
1094  // Form and check allocation and deallocation calls.
1095  assert(!IsPromiseDependentType &&
1096  "cannot make statement while the promise type is dependent");
1097  QualType PromiseType = Fn.CoroutinePromise->getType();
1098 
1099  if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
1100  return false;
1101 
1102  const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
1103 
1104  // [dcl.fct.def.coroutine]/7
1105  // Lookup allocation functions using a parameter list composed of the
1106  // requested size of the coroutine state being allocated, followed by
1107  // the coroutine function's arguments. If a matching allocation function
1108  // exists, use it. Otherwise, use an allocation function that just takes
1109  // the requested size.
1110 
1111  FunctionDecl *OperatorNew = nullptr;
1112  FunctionDecl *OperatorDelete = nullptr;
1113  FunctionDecl *UnusedResult = nullptr;
1114  bool PassAlignment = false;
1115  SmallVector<Expr *, 1> PlacementArgs;
1116 
1117  // [dcl.fct.def.coroutine]/7
1118  // "The allocation function’s name is looked up in the scope of P.
1119  // [...] If the lookup finds an allocation function in the scope of P,
1120  // overload resolution is performed on a function call created by assembling
1121  // an argument list. The first argument is the amount of space requested,
1122  // and has type std::size_t. The lvalues p1 ... pn are the succeeding
1123  // arguments."
1124  //
1125  // ...where "p1 ... pn" are defined earlier as:
1126  //
1127  // [dcl.fct.def.coroutine]/3
1128  // "For a coroutine f that is a non-static member function, let P1 denote the
1129  // type of the implicit object parameter (13.3.1) and P2 ... Pn be the types
1130  // of the function parameters; otherwise let P1 ... Pn be the types of the
1131  // function parameters. Let p1 ... pn be lvalues denoting those objects."
1132  if (auto *MD = dyn_cast<CXXMethodDecl>(&FD)) {
1133  if (MD->isInstance() && !isLambdaCallOperator(MD)) {
1134  ExprResult ThisExpr = S.ActOnCXXThis(Loc);
1135  if (ThisExpr.isInvalid())
1136  return false;
1137  ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
1138  if (ThisExpr.isInvalid())
1139  return false;
1140  PlacementArgs.push_back(ThisExpr.get());
1141  }
1142  }
1143  for (auto *PD : FD.parameters()) {
1144  if (PD->getType()->isDependentType())
1145  continue;
1146 
1147  // Build a reference to the parameter.
1148  auto PDLoc = PD->getLocation();
1149  ExprResult PDRefExpr =
1150  S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(),
1151  ExprValueKind::VK_LValue, PDLoc);
1152  if (PDRefExpr.isInvalid())
1153  return false;
1154 
1155  PlacementArgs.push_back(PDRefExpr.get());
1156  }
1157  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1158  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1159  /*isArray*/ false, PassAlignment, PlacementArgs,
1160  OperatorNew, UnusedResult, /*Diagnose*/ false);
1161 
1162  // [dcl.fct.def.coroutine]/7
1163  // "If no matching function is found, overload resolution is performed again
1164  // on a function call created by passing just the amount of space required as
1165  // an argument of type std::size_t."
1166  if (!OperatorNew && !PlacementArgs.empty()) {
1167  PlacementArgs.clear();
1168  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1169  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1170  /*isArray*/ false, PassAlignment, PlacementArgs,
1171  OperatorNew, UnusedResult, /*Diagnose*/ false);
1172  }
1173 
1174  // [dcl.fct.def.coroutine]/7
1175  // "The allocation function’s name is looked up in the scope of P. If this
1176  // lookup fails, the allocation function’s name is looked up in the global
1177  // scope."
1178  if (!OperatorNew) {
1179  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Global,
1180  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1181  /*isArray*/ false, PassAlignment, PlacementArgs,
1182  OperatorNew, UnusedResult);
1183  }
1184 
1185  bool IsGlobalOverload =
1186  OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
1187  // If we didn't find a class-local new declaration and non-throwing new
1188  // was is required then we need to lookup the non-throwing global operator
1189  // instead.
1190  if (RequiresNoThrowAlloc && (!OperatorNew || IsGlobalOverload)) {
1191  auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
1192  if (!StdNoThrow)
1193  return false;
1194  PlacementArgs = {StdNoThrow};
1195  OperatorNew = nullptr;
1196  S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Both,
1197  /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1198  /*isArray*/ false, PassAlignment, PlacementArgs,
1199  OperatorNew, UnusedResult);
1200  }
1201 
1202  if (!OperatorNew)
1203  return false;
1204 
1205  if (RequiresNoThrowAlloc) {
1206  const auto *FT = OperatorNew->getType()->getAs<FunctionProtoType>();
1207  if (!FT->isNothrow(/*ResultIfDependent*/ false)) {
1208  S.Diag(OperatorNew->getLocation(),
1209  diag::err_coroutine_promise_new_requires_nothrow)
1210  << OperatorNew;
1211  S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
1212  << OperatorNew;
1213  return false;
1214  }
1215  }
1216 
1217  if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr)
1218  return false;
1219 
1220  Expr *FramePtr =
1221  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
1222 
1223  Expr *FrameSize =
1224  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_size, {});
1225 
1226  // Make new call.
1227 
1228  ExprResult NewRef =
1229  S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
1230  if (NewRef.isInvalid())
1231  return false;
1232 
1233  SmallVector<Expr *, 2> NewArgs(1, FrameSize);
1234  for (auto Arg : PlacementArgs)
1235  NewArgs.push_back(Arg);
1236 
1237  ExprResult NewExpr =
1238  S.ActOnCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
1239  NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
1240  if (NewExpr.isInvalid())
1241  return false;
1242 
1243  // Make delete call.
1244 
1245  QualType OpDeleteQualType = OperatorDelete->getType();
1246 
1247  ExprResult DeleteRef =
1248  S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
1249  if (DeleteRef.isInvalid())
1250  return false;
1251 
1252  Expr *CoroFree =
1253  buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_free, {FramePtr});
1254 
1255  SmallVector<Expr *, 2> DeleteArgs{CoroFree};
1256 
1257  // Check if we need to pass the size.
1258  const auto *OpDeleteType =
1259  OpDeleteQualType.getTypePtr()->getAs<FunctionProtoType>();
1260  if (OpDeleteType->getNumParams() > 1)
1261  DeleteArgs.push_back(FrameSize);
1262 
1263  ExprResult DeleteExpr =
1264  S.ActOnCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
1265  DeleteExpr =
1266  S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
1267  if (DeleteExpr.isInvalid())
1268  return false;
1269 
1270  this->Allocate = NewExpr.get();
1271  this->Deallocate = DeleteExpr.get();
1272 
1273  return true;
1274 }
1275 
1276 bool CoroutineStmtBuilder::makeOnFallthrough() {
1277  assert(!IsPromiseDependentType &&
1278  "cannot make statement while the promise type is dependent");
1279 
1280  // [dcl.fct.def.coroutine]/4
1281  // The unqualified-ids 'return_void' and 'return_value' are looked up in
1282  // the scope of class P. If both are found, the program is ill-formed.
1283  bool HasRVoid, HasRValue;
1284  LookupResult LRVoid =
1285  lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid);
1286  LookupResult LRValue =
1287  lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue);
1288 
1289  StmtResult Fallthrough;
1290  if (HasRVoid && HasRValue) {
1291  // FIXME Improve this diagnostic
1292  S.Diag(FD.getLocation(),
1293  diag::err_coroutine_promise_incompatible_return_functions)
1294  << PromiseRecordDecl;
1295  S.Diag(LRVoid.getRepresentativeDecl()->getLocation(),
1296  diag::note_member_first_declared_here)
1297  << LRVoid.getLookupName();
1298  S.Diag(LRValue.getRepresentativeDecl()->getLocation(),
1299  diag::note_member_first_declared_here)
1300  << LRValue.getLookupName();
1301  return false;
1302  } else if (!HasRVoid && !HasRValue) {
1303  // FIXME: The PDTS currently specifies this case as UB, not ill-formed.
1304  // However we still diagnose this as an error since until the PDTS is fixed.
1305  S.Diag(FD.getLocation(),
1306  diag::err_coroutine_promise_requires_return_function)
1307  << PromiseRecordDecl;
1308  S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1309  << PromiseRecordDecl;
1310  return false;
1311  } else if (HasRVoid) {
1312  // If the unqualified-id return_void is found, flowing off the end of a
1313  // coroutine is equivalent to a co_return with no operand. Otherwise,
1314  // flowing off the end of a coroutine results in undefined behavior.
1315  Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr,
1316  /*IsImplicit*/false);
1317  Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get());
1318  if (Fallthrough.isInvalid())
1319  return false;
1320  }
1321 
1322  this->OnFallthrough = Fallthrough.get();
1323  return true;
1324 }
1325 
1326 bool CoroutineStmtBuilder::makeOnException() {
1327  // Try to form 'p.unhandled_exception();'
1328  assert(!IsPromiseDependentType &&
1329  "cannot make statement while the promise type is dependent");
1330 
1331  const bool RequireUnhandledException = S.getLangOpts().CXXExceptions;
1332 
1333  if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) {
1334  auto DiagID =
1335  RequireUnhandledException
1336  ? diag::err_coroutine_promise_unhandled_exception_required
1337  : diag::
1338  warn_coroutine_promise_unhandled_exception_required_with_exceptions;
1339  S.Diag(Loc, DiagID) << PromiseRecordDecl;
1340  S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1341  << PromiseRecordDecl;
1342  return !RequireUnhandledException;
1343  }
1344 
1345  // If exceptions are disabled, don't try to build OnException.
1346  if (!S.getLangOpts().CXXExceptions)
1347  return true;
1348 
1349  ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
1350  "unhandled_exception", None);
1351  UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
1352  /*DiscardedValue*/ false);
1353  if (UnhandledException.isInvalid())
1354  return false;
1355 
1356  // Since the body of the coroutine will be wrapped in try-catch, it will
1357  // be incompatible with SEH __try if present in a function.
1358  if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) {
1359  S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions);
1360  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1362  return false;
1363  }
1364 
1365  this->OnException = UnhandledException.get();
1366  return true;
1367 }
1368 
1369 bool CoroutineStmtBuilder::makeReturnObject() {
1370  // Build implicit 'p.get_return_object()' expression and form initialization
1371  // of return type from it.
1372  ExprResult ReturnObject =
1373  buildPromiseCall(S, Fn.CoroutinePromise, Loc, "get_return_object", None);
1374  if (ReturnObject.isInvalid())
1375  return false;
1376 
1377  this->ReturnValue = ReturnObject.get();
1378  return true;
1379 }
1380 
1382  if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
1383  auto *MethodDecl = MbrRef->getMethodDecl();
1384  S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here)
1385  << MethodDecl;
1386  }
1387  S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1389 }
1390 
1391 bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
1392  assert(!IsPromiseDependentType &&
1393  "cannot make statement while the promise type is dependent");
1394  assert(this->ReturnValue && "ReturnValue must be already formed");
1395 
1396  QualType const GroType = this->ReturnValue->getType();
1397  assert(!GroType->isDependentType() &&
1398  "get_return_object type must no longer be dependent");
1399 
1400  QualType const FnRetType = FD.getReturnType();
1401  assert(!FnRetType->isDependentType() &&
1402  "get_return_object type must no longer be dependent");
1403 
1404  if (FnRetType->isVoidType()) {
1405  ExprResult Res =
1406  S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
1407  if (Res.isInvalid())
1408  return false;
1409 
1410  this->ResultDecl = Res.get();
1411  return true;
1412  }
1413 
1414  if (GroType->isVoidType()) {
1415  // Trigger a nice error message.
1416  InitializedEntity Entity =
1417  InitializedEntity::InitializeResult(Loc, FnRetType, false);
1418  S.PerformMoveOrCopyInitialization(Entity, nullptr, FnRetType, ReturnValue);
1420  return false;
1421  }
1422 
1423  auto *GroDecl = VarDecl::Create(
1424  S.Context, &FD, FD.getLocation(), FD.getLocation(),
1425  &S.PP.getIdentifierTable().get("__coro_gro"), GroType,
1426  S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
1427 
1428  S.CheckVariableDeclarationType(GroDecl);
1429  if (GroDecl->isInvalidDecl())
1430  return false;
1431 
1433  ExprResult Res = S.PerformMoveOrCopyInitialization(Entity, nullptr, GroType,
1434  this->ReturnValue);
1435  if (Res.isInvalid())
1436  return false;
1437 
1438  Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
1439  if (Res.isInvalid())
1440  return false;
1441 
1442  S.AddInitializerToDecl(GroDecl, Res.get(),
1443  /*DirectInit=*/false);
1444 
1445  S.FinalizeDeclaration(GroDecl);
1446 
1447  // Form a declaration statement for the return declaration, so that AST
1448  // visitors can more easily find it.
1449  StmtResult GroDeclStmt =
1450  S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
1451  if (GroDeclStmt.isInvalid())
1452  return false;
1453 
1454  this->ResultDecl = GroDeclStmt.get();
1455 
1456  ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
1457  if (declRef.isInvalid())
1458  return false;
1459 
1460  StmtResult ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
1461  if (ReturnStmt.isInvalid()) {
1463  return false;
1464  }
1465  if (cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl)
1466  GroDecl->setNRVOVariable(true);
1467 
1468  this->ReturnStmt = ReturnStmt.get();
1469  return true;
1470 }
1471 
1472 // Create a static_cast<T&&>(expr).
1473 static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) {
1474  if (T.isNull())
1475  T = E->getType();
1476  QualType TargetType = S.BuildReferenceType(
1477  T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName());
1478  SourceLocation ExprLoc = E->getBeginLoc();
1479  TypeSourceInfo *TargetLoc =
1480  S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc);
1481 
1482  return S
1483  .BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
1484  SourceRange(ExprLoc, ExprLoc), E->getSourceRange())
1485  .get();
1486 }
1487 
1488 /// Build a variable declaration for move parameter.
1490  IdentifierInfo *II) {
1491  TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc);
1492  VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type,
1493  TInfo, SC_None);
1494  Decl->setImplicit();
1495  return Decl;
1496 }
1497 
1498 // Build statements that move coroutine function parameters to the coroutine
1499 // frame, and store them on the function scope info.
1501  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
1502  auto *FD = cast<FunctionDecl>(CurContext);
1503 
1504  auto *ScopeInfo = getCurFunction();
1505  assert(ScopeInfo->CoroutineParameterMoves.empty() &&
1506  "Should not build parameter moves twice");
1507 
1508  for (auto *PD : FD->parameters()) {
1509  if (PD->getType()->isDependentType())
1510  continue;
1511 
1512  ExprResult PDRefExpr =
1513  BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(),
1514  ExprValueKind::VK_LValue, Loc); // FIXME: scope?
1515  if (PDRefExpr.isInvalid())
1516  return false;
1517 
1518  Expr *CExpr = nullptr;
1519  if (PD->getType()->getAsCXXRecordDecl() ||
1520  PD->getType()->isRValueReferenceType())
1521  CExpr = castForMoving(*this, PDRefExpr.get());
1522  else
1523  CExpr = PDRefExpr.get();
1524 
1525  auto D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier());
1526  AddInitializerToDecl(D, CExpr, /*DirectInit=*/true);
1527 
1528  // Convert decl to a statement.
1529  StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc);
1530  if (Stmt.isInvalid())
1531  return false;
1532 
1533  ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get()));
1534  }
1535  return true;
1536 }
1537 
1539  CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args);
1540  if (!Res)
1541  return StmtError();
1542  return Res;
1543 }
1544 
1546  SourceLocation FuncLoc) {
1547  if (!StdCoroutineTraitsCache) {
1548  if (auto StdExp = lookupStdExperimentalNamespace()) {
1549  LookupResult Result(*this,
1550  &PP.getIdentifierTable().get("coroutine_traits"),
1551  FuncLoc, LookupOrdinaryName);
1552  if (!LookupQualifiedName(Result, StdExp)) {
1553  Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
1554  << "std::experimental::coroutine_traits";
1555  return nullptr;
1556  }
1557  if (!(StdCoroutineTraitsCache =
1558  Result.getAsSingle<ClassTemplateDecl>())) {
1559  Result.suppressDiagnostics();
1560  NamedDecl *Found = *Result.begin();
1561  Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits);
1562  return nullptr;
1563  }
1564  }
1565  }
1566  return StdCoroutineTraitsCache;
1567 }
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:548
Represents a function declaration or definition.
Definition: Decl.h:1738
Represents a &#39;co_await&#39; expression while the type of the promise is dependent.
Definition: ExprCXX.h:4455
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:4023
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2537
A (possibly-)qualified type.
Definition: Type.h:638
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:3055
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:435
Stmt - This represents one statement.
Definition: Stmt.h:66
bool isSpecificPlaceholderType(unsigned K) const
Test for a specific placeholder type.
Definition: Type.h:6531
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:1308
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:87
A reference to a name which we were able to look up during parsing but could not resolve to a specifi...
Definition: ExprCXX.h:2828
Scope * TUScope
Translation Unit Scope - useful to Objective-C actions that need to lookup file scope declarations in...
Definition: Sema.h:828
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:6245
The base class of the type hierarchy.
Definition: Type.h:1407
OpaqueValueExpr * OpaqueValue
StringRef getFirstCoroutineStmtKeyword() const
Definition: ScopeInfo.h:458
Represent a C++ namespace.
Definition: Decl.h:515
A container of type source information.
Definition: Decl.h:87
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:14628
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:813
ActionResult< Stmt * > StmtResult
Definition: Ownership.h:268
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:241
QualType getReturnType() const
Definition: Decl.h:2302
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6748
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:5349
bool isAmbiguous() const
Definition: Lookup.h:290
bool isInvalidDecl() const
Definition: DeclBase.h:542
static InitializedEntity InitializeResult(SourceLocation ReturnLoc, QualType Type, bool NRVO)
Create the initialization entity for the result of a function.
static bool diagReturnOnAllocFailure(Sema &S, Expr *E, CXXRecordDecl *PromiseRecordDecl, FunctionScopeInfo &Fn)
Defines the clang::Expr interface and subclasses for C++ expressions.
ExprResult ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc, MultiExprArg ArgExprs, SourceLocation RParenLoc, Expr *ExecConfig=nullptr, bool IsExecConfig=false)
ActOnCallExpr - Handle a call to Fn with the specified array of arguments.
Definition: SemaExpr.cpp:5421
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:289
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:3895
bool ActOnCoroutineBodyStart(Scope *S, SourceLocation KwLoc, StringRef Keyword)
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:288
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:6308
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Decl.h:739
IdentifierTable & Idents
Definition: ASTContext.h:566
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:110
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2262
static ParenListExpr * Create(const ASTContext &Ctx, SourceLocation LParenLoc, ArrayRef< Expr *> Exprs, SourceLocation RParenLoc)
Create a paren list.
Definition: Expr.cpp:4051
bool isCompleteType(SourceLocation Loc, QualType T)
Definition: Sema.h:1655
Represents the results of name lookup.
Definition: Lookup.h:47
PtrTy get() const
Definition: Ownership.h:174
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:555
ExprValueKind getValueKind() const
getValueKind - The value kind that this expression produces.
Definition: Expr.h:405
StmtResult StmtError()
Definition: Ownership.h:284
Represents a declaration of a type.
Definition: Decl.h:2874
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:41
const Type * getTypePtr() const
Retrieves a pointer to the underlying (unqualified) type.
Definition: Type.h:6072
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:7286
Preprocessor & PP
Definition: Sema.h:323
static VarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S)
Definition: Decl.cpp:1918
const LangOptions & getLangOpts() const
Definition: Sema.h:1231
bool isLambdaCallOperator(const CXXMethodDecl *MD)
Definition: ASTLambda.h:28
bool isUnevaluatedContext() const
Determines whether we are currently in a context that is not evaluated as per C++ [expr] p5...
Definition: Sema.h:7549
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:3063
ExprResult BuildDeclarationNameExpr(const CXXScopeSpec &SS, LookupResult &R, bool NeedsADL, bool AcceptInvalidDecl=false)
Definition: SemaExpr.cpp:2797
static UnresolvedLookupExpr * Create(const ASTContext &Context, CXXRecordDecl *NamingClass, NestedNameSpecifierLoc QualifierLoc, const DeclarationNameInfo &NameInfo, bool RequiresADL, bool Overloaded, UnresolvedSetIterator Begin, UnresolvedSetIterator End)
Definition: ExprCXX.cpp:325
QualType CheckTemplateIdType(TemplateName Template, SourceLocation TemplateLoc, TemplateArgumentListInfo &TemplateArgs)
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:278
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:1613
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3687
StmtResult BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp)
Definition: SemaStmt.cpp:3520
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:86
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:10729
This represents one expression.
Definition: Expr.h:106
int Id
Definition: ASTDiff.cpp:191
ClassTemplateDecl * lookupCoroutineTraits(SourceLocation KwLoc, SourceLocation FuncLoc)
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6811
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.
DeclContext * getDeclContext()
Definition: DeclBase.h:427
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:2532
Represents a C++ template name within the type system.
Definition: TemplateName.h:179
decls_iterator decls_begin() const
Definition: ExprCXX.h:2727
bool RequireCompleteType(SourceLocation Loc, QualType T, TypeDiagnoser &Diagnoser)
Ensure that the type T is a complete type.
Definition: SemaType.cpp:7598
static bool isValidCoroutineContext(Sema &S, SourceLocation Loc, StringRef Keyword)
QualType getType() const
Definition: Expr.h:128
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:2443
static Expr * buildBuiltinCall(Sema &S, SourceLocation Loc, Builtin::ID Id, MultiExprArg CallArgs)
bool isInvalid() const
Definition: Ownership.h:170
bool isUsable() const
Definition: Ownership.h:171
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:1396
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:703
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:412
static CoroutineBodyStmt * Create(const ASTContext &C, CtorArgs const &Args)
Definition: StmtCXX.cpp:87
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:945
Kind
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:157
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:3613
void FinalizeDeclaration(Decl *D)
FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform any semantic actions neces...
Definition: SemaDecl.cpp:12009
FunctionDecl * FindUsualDeallocationFunction(SourceLocation StartLoc, bool CanProvideSize, bool Overaligned, DeclarationName Name)
IdentifierTable & getIdentifierTable()
Definition: Preprocessor.h:823
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:2041
Only look for allocation functions in the scope of the allocated class.
Definition: Sema.h:5229
ArrayRef< Stmt * > ParamMoves
Definition: StmtCXX.h:345
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:1975
An rvalue ref-qualifier was provided (&&).
Definition: Type.h:1366
void addArgument(const TemplateArgumentLoc &Loc)
Definition: TemplateBase.h:595
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:6518
Represents a template argument.
Definition: TemplateBase.h:51
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:1262
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:4502
The name of a declaration.
NamedDecl * getFoundDecl() const
Fetch the unique decl found by this lookup.
Definition: Lookup.h:506
bool isBooleanType() const
Definition: Type.h:6657
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:1396
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:10977
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:320
Represents the body of a coroutine.
Definition: StmtCXX.h:302
Location wrapper for a TemplateArgument.
Definition: TemplateBase.h:450
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:5232
CanQualType DependentTy
Definition: ASTContext.h:1045
Represents a &#39;co_await&#39; expression.
Definition: ExprCXX.h:4419
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:12867
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:821
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:3076
ExprResult BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK, SourceLocation Loc, const CXXScopeSpec *SS=nullptr)
Definition: SemaExpr.cpp:1700
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:5226
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
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:6544
sema::FunctionScopeInfo * getCurFunction() const
Definition: Sema.h:1358
Builtin::Context & BuiltinInfo
Definition: ASTContext.h:568
DeclContext * CurContext
CurContext - This is the current declaration context of parsing.
Definition: Sema.h:336
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:276
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2396
ExprResult ExprError()
Definition: Ownership.h:283
bool isDependentType() const
Whether this type is a dependent type, meaning that its definition somehow depends on a template para...
Definition: Type.h:2079
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:572
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:648
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:114
A trivial tuple used to represent a source range.
ASTContext & Context
Definition: Sema.h:324
This represents a decl that may have a name.
Definition: Decl.h:249
No keyword precedes the qualified type name.
Definition: Type.h:5071
Describes an entity that is being initialized.
Look up of an operator name (e.g., operator+) for use with operator overloading.
Definition: Sema.h:3067
NamedDecl * getRepresentativeDecl() const
Fetches a representative decl. Useful for lazy diagnostics.
Definition: Lookup.h:513
Decl * getCalleeDecl()
Definition: Expr.h:2526
decls_iterator decls_end() const
Definition: ExprCXX.h:2730
static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD, SourceLocation Loc, bool &Res)
SourceLocation getLocation() const
Definition: DeclBase.h:418
LangStandard::Kind Std
VarDecl * buildCoroutinePromise(SourceLocation Loc)
static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn)