Bug Summary

File:clang/lib/Sema/SemaCoroutine.cpp
Warning:line 700, column 13
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaCoroutine.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-12/lib/clang/12.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema -I /build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/include -I /build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/build-llvm/include -I /build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-12/lib/clang/12.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2021-01-15-025533-4418-1 -x c++ /build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp
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/Basic/Builtins.h"
22#include "clang/Lex/Preprocessor.h"
23#include "clang/Sema/Initialization.h"
24#include "clang/Sema/Overload.h"
25#include "clang/Sema/ScopeInfo.h"
26#include "clang/Sema/SemaInternal.h"
27#include "llvm/ADT/SmallSet.h"
28
29using namespace clang;
30using namespace sema;
31
32static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
33 SourceLocation Loc, bool &Res) {
34 DeclarationName DN = S.PP.getIdentifierInfo(Name);
35 LookupResult LR(S, DN, Loc, Sema::LookupMemberName);
36 // Suppress diagnostics when a private member is selected. The same warnings
37 // will be produced again when building the call.
38 LR.suppressDiagnostics();
39 Res = S.LookupQualifiedName(LR, RD);
40 return LR;
41}
42
43static bool lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
44 SourceLocation Loc) {
45 bool Res;
46 lookupMember(S, Name, RD, Loc, Res);
47 return Res;
48}
49
50/// Look up the std::coroutine_traits<...>::promise_type for the given
51/// function type.
52static QualType lookupPromiseType(Sema &S, const FunctionDecl *FD,
53 SourceLocation KwLoc) {
54 const FunctionProtoType *FnType = FD->getType()->castAs<FunctionProtoType>();
55 const SourceLocation FuncLoc = FD->getLocation();
56 // FIXME: Cache std::coroutine_traits once we've found it.
57 NamespaceDecl *StdExp = S.lookupStdExperimentalNamespace();
58 if (!StdExp) {
59 S.Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
60 << "std::experimental::coroutine_traits";
61 return QualType();
62 }
63
64 ClassTemplateDecl *CoroTraits = S.lookupCoroutineTraits(KwLoc, FuncLoc);
65 if (!CoroTraits) {
66 return QualType();
67 }
68
69 // Form template argument list for coroutine_traits<R, P1, P2, ...> according
70 // to [dcl.fct.def.coroutine]3
71 TemplateArgumentListInfo Args(KwLoc, KwLoc);
72 auto AddArg = [&](QualType T) {
73 Args.addArgument(TemplateArgumentLoc(
74 TemplateArgument(T), S.Context.getTrivialTypeSourceInfo(T, KwLoc)));
75 };
76 AddArg(FnType->getReturnType());
77 // If the function is a non-static member function, add the type
78 // of the implicit object parameter before the formal parameters.
79 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
80 if (MD->isInstance()) {
81 // [over.match.funcs]4
82 // For non-static member functions, the type of the implicit object
83 // parameter is
84 // -- "lvalue reference to cv X" for functions declared without a
85 // ref-qualifier or with the & ref-qualifier
86 // -- "rvalue reference to cv X" for functions declared with the &&
87 // ref-qualifier
88 QualType T = MD->getThisType()->castAs<PointerType>()->getPointeeType();
89 T = FnType->getRefQualifier() == RQ_RValue
90 ? S.Context.getRValueReferenceType(T)
91 : S.Context.getLValueReferenceType(T, /*SpelledAsLValue*/ true);
92 AddArg(T);
93 }
94 }
95 for (QualType T : FnType->getParamTypes())
96 AddArg(T);
97
98 // Build the template-id.
99 QualType CoroTrait =
100 S.CheckTemplateIdType(TemplateName(CoroTraits), KwLoc, Args);
101 if (CoroTrait.isNull())
102 return QualType();
103 if (S.RequireCompleteType(KwLoc, CoroTrait,
104 diag::err_coroutine_type_missing_specialization))
105 return QualType();
106
107 auto *RD = CoroTrait->getAsCXXRecordDecl();
108 assert(RD && "specialization of class template is not a class?")((RD && "specialization of class template is not a class?"
) ? static_cast<void> (0) : __assert_fail ("RD && \"specialization of class template is not a class?\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 108, __PRETTY_FUNCTION__))
;
109
110 // Look up the ::promise_type member.
111 LookupResult R(S, &S.PP.getIdentifierTable().get("promise_type"), KwLoc,
112 Sema::LookupOrdinaryName);
113 S.LookupQualifiedName(R, RD);
114 auto *Promise = R.getAsSingle<TypeDecl>();
115 if (!Promise) {
116 S.Diag(FuncLoc,
117 diag::err_implied_std_coroutine_traits_promise_type_not_found)
118 << RD;
119 return QualType();
120 }
121 // The promise type is required to be a class type.
122 QualType PromiseType = S.Context.getTypeDeclType(Promise);
123
124 auto buildElaboratedType = [&]() {
125 auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, StdExp);
126 NNS = NestedNameSpecifier::Create(S.Context, NNS, false,
127 CoroTrait.getTypePtr());
128 return S.Context.getElaboratedType(ETK_None, NNS, PromiseType);
129 };
130
131 if (!PromiseType->getAsCXXRecordDecl()) {
132 S.Diag(FuncLoc,
133 diag::err_implied_std_coroutine_traits_promise_type_not_class)
134 << buildElaboratedType();
135 return QualType();
136 }
137 if (S.RequireCompleteType(FuncLoc, buildElaboratedType(),
138 diag::err_coroutine_promise_type_incomplete))
139 return QualType();
140
141 return PromiseType;
142}
143
144/// Look up the std::experimental::coroutine_handle<PromiseType>.
145static QualType lookupCoroutineHandleType(Sema &S, QualType PromiseType,
146 SourceLocation Loc) {
147 if (PromiseType.isNull())
148 return QualType();
149
150 NamespaceDecl *StdExp = S.lookupStdExperimentalNamespace();
151 assert(StdExp && "Should already be diagnosed")((StdExp && "Should already be diagnosed") ? static_cast
<void> (0) : __assert_fail ("StdExp && \"Should already be diagnosed\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 151, __PRETTY_FUNCTION__))
;
152
153 LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_handle"),
154 Loc, Sema::LookupOrdinaryName);
155 if (!S.LookupQualifiedName(Result, StdExp)) {
156 S.Diag(Loc, diag::err_implied_coroutine_type_not_found)
157 << "std::experimental::coroutine_handle";
158 return QualType();
159 }
160
161 ClassTemplateDecl *CoroHandle = Result.getAsSingle<ClassTemplateDecl>();
162 if (!CoroHandle) {
163 Result.suppressDiagnostics();
164 // We found something weird. Complain about the first thing we found.
165 NamedDecl *Found = *Result.begin();
166 S.Diag(Found->getLocation(), diag::err_malformed_std_coroutine_handle);
167 return QualType();
168 }
169
170 // Form template argument list for coroutine_handle<Promise>.
171 TemplateArgumentListInfo Args(Loc, Loc);
172 Args.addArgument(TemplateArgumentLoc(
173 TemplateArgument(PromiseType),
174 S.Context.getTrivialTypeSourceInfo(PromiseType, Loc)));
175
176 // Build the template-id.
177 QualType CoroHandleType =
178 S.CheckTemplateIdType(TemplateName(CoroHandle), Loc, Args);
179 if (CoroHandleType.isNull())
180 return QualType();
181 if (S.RequireCompleteType(Loc, CoroHandleType,
182 diag::err_coroutine_type_missing_specialization))
183 return QualType();
184
185 return CoroHandleType;
186}
187
188static bool isValidCoroutineContext(Sema &S, SourceLocation Loc,
189 StringRef Keyword) {
190 // [expr.await]p2 dictates that 'co_await' and 'co_yield' must be used within
191 // a function body.
192 // FIXME: This also covers [expr.await]p2: "An await-expression shall not
193 // appear in a default argument." But the diagnostic QoI here could be
194 // improved to inform the user that default arguments specifically are not
195 // allowed.
196 auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
197 if (!FD) {
198 S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
199 ? diag::err_coroutine_objc_method
200 : diag::err_coroutine_outside_function) << Keyword;
201 return false;
202 }
203
204 // An enumeration for mapping the diagnostic type to the correct diagnostic
205 // selection index.
206 enum InvalidFuncDiag {
207 DiagCtor = 0,
208 DiagDtor,
209 DiagMain,
210 DiagConstexpr,
211 DiagAutoRet,
212 DiagVarargs,
213 DiagConsteval,
214 };
215 bool Diagnosed = false;
216 auto DiagInvalid = [&](InvalidFuncDiag ID) {
217 S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
218 Diagnosed = true;
219 return false;
220 };
221
222 // Diagnose when a constructor, destructor
223 // or the function 'main' are declared as a coroutine.
224 auto *MD = dyn_cast<CXXMethodDecl>(FD);
225 // [class.ctor]p11: "A constructor shall not be a coroutine."
226 if (MD && isa<CXXConstructorDecl>(MD))
227 return DiagInvalid(DiagCtor);
228 // [class.dtor]p17: "A destructor shall not be a coroutine."
229 else if (MD && isa<CXXDestructorDecl>(MD))
230 return DiagInvalid(DiagDtor);
231 // [basic.start.main]p3: "The function main shall not be a coroutine."
232 else if (FD->isMain())
233 return DiagInvalid(DiagMain);
234
235 // Emit a diagnostics for each of the following conditions which is not met.
236 // [expr.const]p2: "An expression e is a core constant expression unless the
237 // evaluation of e [...] would evaluate one of the following expressions:
238 // [...] an await-expression [...] a yield-expression."
239 if (FD->isConstexpr())
240 DiagInvalid(FD->isConsteval() ? DiagConsteval : DiagConstexpr);
241 // [dcl.spec.auto]p15: "A function declared with a return type that uses a
242 // placeholder type shall not be a coroutine."
243 if (FD->getReturnType()->isUndeducedType())
244 DiagInvalid(DiagAutoRet);
245 // [dcl.fct.def.coroutine]p1: "The parameter-declaration-clause of the
246 // coroutine shall not terminate with an ellipsis that is not part of a
247 // parameter-declaration."
248 if (FD->isVariadic())
249 DiagInvalid(DiagVarargs);
250
251 return !Diagnosed;
252}
253
254static ExprResult buildOperatorCoawaitLookupExpr(Sema &SemaRef, Scope *S,
255 SourceLocation Loc) {
256 DeclarationName OpName =
257 SemaRef.Context.DeclarationNames.getCXXOperatorName(OO_Coawait);
258 LookupResult Operators(SemaRef, OpName, SourceLocation(),
259 Sema::LookupOperatorName);
260 SemaRef.LookupName(Operators, S);
261
262 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous")((!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"
) ? static_cast<void> (0) : __assert_fail ("!Operators.isAmbiguous() && \"Operator lookup cannot be ambiguous\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 262, __PRETTY_FUNCTION__))
;
263 const auto &Functions = Operators.asUnresolvedSet();
264 bool IsOverloaded =
265 Functions.size() > 1 ||
266 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
267 Expr *CoawaitOp = UnresolvedLookupExpr::Create(
268 SemaRef.Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(),
269 DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded,
270 Functions.begin(), Functions.end());
271 assert(CoawaitOp)((CoawaitOp) ? static_cast<void> (0) : __assert_fail ("CoawaitOp"
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 271, __PRETTY_FUNCTION__))
;
272 return CoawaitOp;
273}
274
275/// Build a call to 'operator co_await' if there is a suitable operator for
276/// the given expression.
277static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, SourceLocation Loc,
278 Expr *E,
279 UnresolvedLookupExpr *Lookup) {
280 UnresolvedSet<16> Functions;
281 Functions.append(Lookup->decls_begin(), Lookup->decls_end());
282 return SemaRef.CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E);
283}
284
285static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, Scope *S,
286 SourceLocation Loc, Expr *E) {
287 ExprResult R = buildOperatorCoawaitLookupExpr(SemaRef, S, Loc);
288 if (R.isInvalid())
289 return ExprError();
290 return buildOperatorCoawaitCall(SemaRef, Loc, E,
291 cast<UnresolvedLookupExpr>(R.get()));
292}
293
294static Expr *buildBuiltinCall(Sema &S, SourceLocation Loc, Builtin::ID Id,
295 MultiExprArg CallArgs) {
296 StringRef Name = S.Context.BuiltinInfo.getName(Id);
297 LookupResult R(S, &S.Context.Idents.get(Name), Loc, Sema::LookupOrdinaryName);
298 S.LookupName(R, S.TUScope, /*AllowBuiltinCreation=*/true);
299
300 auto *BuiltInDecl = R.getAsSingle<FunctionDecl>();
301 assert(BuiltInDecl && "failed to find builtin declaration")((BuiltInDecl && "failed to find builtin declaration"
) ? static_cast<void> (0) : __assert_fail ("BuiltInDecl && \"failed to find builtin declaration\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 301, __PRETTY_FUNCTION__))
;
302
303 ExprResult DeclRef =
304 S.BuildDeclRefExpr(BuiltInDecl, BuiltInDecl->getType(), VK_LValue, Loc);
305 assert(DeclRef.isUsable() && "Builtin reference cannot fail")((DeclRef.isUsable() && "Builtin reference cannot fail"
) ? static_cast<void> (0) : __assert_fail ("DeclRef.isUsable() && \"Builtin reference cannot fail\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 305, __PRETTY_FUNCTION__))
;
306
307 ExprResult Call =
308 S.BuildCallExpr(/*Scope=*/nullptr, DeclRef.get(), Loc, CallArgs, Loc);
309
310 assert(!Call.isInvalid() && "Call to builtin cannot fail!")((!Call.isInvalid() && "Call to builtin cannot fail!"
) ? static_cast<void> (0) : __assert_fail ("!Call.isInvalid() && \"Call to builtin cannot fail!\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 310, __PRETTY_FUNCTION__))
;
311 return Call.get();
312}
313
314static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType,
315 SourceLocation Loc) {
316 QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
317 if (CoroHandleType.isNull())
318 return ExprError();
319
320 DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType);
321 LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc,
322 Sema::LookupOrdinaryName);
323 if (!S.LookupQualifiedName(Found, LookupCtx)) {
324 S.Diag(Loc, diag::err_coroutine_handle_missing_member)
325 << "from_address";
326 return ExprError();
327 }
328
329 Expr *FramePtr =
330 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
331
332 CXXScopeSpec SS;
333 ExprResult FromAddr =
334 S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
335 if (FromAddr.isInvalid())
336 return ExprError();
337
338 return S.BuildCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc);
339}
340
341struct ReadySuspendResumeResult {
342 enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
343 Expr *Results[3];
344 OpaqueValueExpr *OpaqueValue;
345 bool IsInvalid;
346};
347
348static ExprResult buildMemberCall(Sema &S, Expr *Base, SourceLocation Loc,
349 StringRef Name, MultiExprArg Args) {
350 DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc);
351
352 // FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&.
353 CXXScopeSpec SS;
354 ExprResult Result = S.BuildMemberReferenceExpr(
355 Base, Base->getType(), Loc, /*IsPtr=*/false, SS,
356 SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr,
357 /*Scope=*/nullptr);
358 if (Result.isInvalid())
359 return ExprError();
360
361 // We meant exactly what we asked for. No need for typo correction.
362 if (auto *TE = dyn_cast<TypoExpr>(Result.get())) {
363 S.clearDelayedTypo(TE);
364 S.Diag(Loc, diag::err_no_member)
365 << NameInfo.getName() << Base->getType()->getAsCXXRecordDecl()
366 << Base->getSourceRange();
367 return ExprError();
368 }
369
370 return S.BuildCallExpr(nullptr, Result.get(), Loc, Args, Loc, nullptr);
371}
372
373// See if return type is coroutine-handle and if so, invoke builtin coro-resume
374// on its address. This is to enable experimental support for coroutine-handle
375// returning await_suspend that results in a guaranteed tail call to the target
376// coroutine.
377static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
378 SourceLocation Loc) {
379 if (RetType->isReferenceType())
380 return nullptr;
381 Type const *T = RetType.getTypePtr();
382 if (!T->isClassType() && !T->isStructureType())
383 return nullptr;
384
385 // FIXME: Add convertability check to coroutine_handle<>. Possibly via
386 // EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment
387 // a private function in SemaExprCXX.cpp
388
389 ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", None);
390 if (AddressExpr.isInvalid())
391 return nullptr;
392
393 Expr *JustAddress = AddressExpr.get();
394
395 // Check that the type of AddressExpr is void*
396 if (!JustAddress->getType().getTypePtr()->isVoidPointerType())
397 S.Diag(cast<CallExpr>(JustAddress)->getCalleeDecl()->getLocation(),
398 diag::warn_coroutine_handle_address_invalid_return_type)
399 << JustAddress->getType();
400
401 // Clean up temporary objects so that they don't live across suspension points
402 // unnecessarily. We choose to clean up before the call to
403 // __builtin_coro_resume so that the cleanup code are not inserted in-between
404 // the resume call and return instruction, which would interfere with the
405 // musttail call contract.
406 JustAddress = S.MaybeCreateExprWithCleanups(JustAddress);
407 return buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_resume,
408 JustAddress);
409}
410
411/// Build calls to await_ready, await_suspend, and await_resume for a co_await
412/// expression.
413/// The generated AST tries to clean up temporary objects as early as
414/// possible so that they don't live across suspension points if possible.
415/// Having temporary objects living across suspension points unnecessarily can
416/// lead to large frame size, and also lead to memory corruptions if the
417/// coroutine frame is destroyed after coming back from suspension. This is done
418/// by wrapping both the await_ready call and the await_suspend call with
419/// ExprWithCleanups. In the end of this function, we also need to explicitly
420/// set cleanup state so that the CoawaitExpr is also wrapped with an
421/// ExprWithCleanups to clean up the awaiter associated with the co_await
422/// expression.
423static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
424 SourceLocation Loc, Expr *E) {
425 OpaqueValueExpr *Operand = new (S.Context)
426 OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
427
428 // Assume valid until we see otherwise.
429 // Further operations are responsible for setting IsInalid to true.
430 ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/false};
431
432 using ACT = ReadySuspendResumeResult::AwaitCallType;
433
434 auto BuildSubExpr = [&](ACT CallType, StringRef Func,
435 MultiExprArg Arg) -> Expr * {
436 ExprResult Result = buildMemberCall(S, Operand, Loc, Func, Arg);
437 if (Result.isInvalid()) {
438 Calls.IsInvalid = true;
439 return nullptr;
440 }
441 Calls.Results[CallType] = Result.get();
442 return Result.get();
443 };
444
445 CallExpr *AwaitReady =
446 cast_or_null<CallExpr>(BuildSubExpr(ACT::ACT_Ready, "await_ready", None));
447 if (!AwaitReady)
448 return Calls;
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 } else
461 Calls.Results[ACT::ACT_Ready] = S.MaybeCreateExprWithCleanups(Conv.get());
462 }
463
464 ExprResult CoroHandleRes =
465 buildCoroutineHandle(S, CoroPromise->getType(), Loc);
466 if (CoroHandleRes.isInvalid()) {
467 Calls.IsInvalid = true;
468 return Calls;
469 }
470 Expr *CoroHandle = CoroHandleRes.get();
471 CallExpr *AwaitSuspend = cast_or_null<CallExpr>(
472 BuildSubExpr(ACT::ACT_Suspend, "await_suspend", CoroHandle));
473 if (!AwaitSuspend)
474 return Calls;
475 if (!AwaitSuspend->getType()->isDependentType()) {
476 // [expr.await]p3 [...]
477 // - await-suspend is the expression e.await_suspend(h), which shall be
478 // a prvalue of type void, bool, or std::coroutine_handle<Z> for some
479 // type Z.
480 QualType RetType = AwaitSuspend->getCallReturnType(S.Context);
481
482 // Experimental support for coroutine_handle returning await_suspend.
483 if (Expr *TailCallSuspend =
484 maybeTailCall(S, RetType, AwaitSuspend, Loc))
485 // Note that we don't wrap the expression with ExprWithCleanups here
486 // because that might interfere with tailcall contract (e.g. inserting
487 // clean up instructions in-between tailcall and return). Instead
488 // ExprWithCleanups is wrapped within maybeTailCall() prior to the resume
489 // call.
490 Calls.Results[ACT::ACT_Suspend] = TailCallSuspend;
491 else {
492 // non-class prvalues always have cv-unqualified types
493 if (RetType->isReferenceType() ||
494 (!RetType->isBooleanType() && !RetType->isVoidType())) {
495 S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(),
496 diag::err_await_suspend_invalid_return_type)
497 << RetType;
498 S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
499 << AwaitSuspend->getDirectCallee();
500 Calls.IsInvalid = true;
501 } else
502 Calls.Results[ACT::ACT_Suspend] =
503 S.MaybeCreateExprWithCleanups(AwaitSuspend);
504 }
505 }
506
507 BuildSubExpr(ACT::ACT_Resume, "await_resume", None);
508
509 // Make sure the awaiter object gets a chance to be cleaned up.
510 S.Cleanup.setExprNeedsCleanups(true);
511
512 return Calls;
513}
514
515static ExprResult buildPromiseCall(Sema &S, VarDecl *Promise,
516 SourceLocation Loc, StringRef Name,
517 MultiExprArg Args) {
518
519 // Form a reference to the promise.
520 ExprResult PromiseRef = S.BuildDeclRefExpr(
521 Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc);
522 if (PromiseRef.isInvalid())
523 return ExprError();
524
525 return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
526}
527
528VarDecl *Sema::buildCoroutinePromise(SourceLocation Loc) {
529 assert(isa<FunctionDecl>(CurContext) && "not in a function scope")((isa<FunctionDecl>(CurContext) && "not in a function scope"
) ? static_cast<void> (0) : __assert_fail ("isa<FunctionDecl>(CurContext) && \"not in a function scope\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 529, __PRETTY_FUNCTION__))
;
530 auto *FD = cast<FunctionDecl>(CurContext);
531 bool IsThisDependentType = [&] {
532 if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
533 return MD->isInstance() && MD->getThisType()->isDependentType();
534 else
535 return false;
536 }();
537
538 QualType T = FD->getType()->isDependentType() || IsThisDependentType
539 ? Context.DependentTy
540 : lookupPromiseType(*this, FD, Loc);
541 if (T.isNull())
542 return nullptr;
543
544 auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(),
545 &PP.getIdentifierTable().get("__promise"), T,
546 Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
547 VD->setImplicit();
548 CheckVariableDeclarationType(VD);
549 if (VD->isInvalidDecl())
550 return nullptr;
551
552 auto *ScopeInfo = getCurFunction();
553
554 // Build a list of arguments, based on the coroutine function's arguments,
555 // that if present will be passed to the promise type's constructor.
556 llvm::SmallVector<Expr *, 4> CtorArgExprs;
557
558 // Add implicit object parameter.
559 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
560 if (MD->isInstance() && !isLambdaCallOperator(MD)) {
561 ExprResult ThisExpr = ActOnCXXThis(Loc);
562 if (ThisExpr.isInvalid())
563 return nullptr;
564 ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
565 if (ThisExpr.isInvalid())
566 return nullptr;
567 CtorArgExprs.push_back(ThisExpr.get());
568 }
569 }
570
571 // Add the coroutine function's parameters.
572 auto &Moves = ScopeInfo->CoroutineParameterMoves;
573 for (auto *PD : FD->parameters()) {
574 if (PD->getType()->isDependentType())
575 continue;
576
577 auto RefExpr = ExprEmpty();
578 auto Move = Moves.find(PD);
579 assert(Move != Moves.end() &&((Move != Moves.end() && "Coroutine function parameter not inserted into move map"
) ? static_cast<void> (0) : __assert_fail ("Move != Moves.end() && \"Coroutine function parameter not inserted into move map\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 580, __PRETTY_FUNCTION__))
580 "Coroutine function parameter not inserted into move map")((Move != Moves.end() && "Coroutine function parameter not inserted into move map"
) ? static_cast<void> (0) : __assert_fail ("Move != Moves.end() && \"Coroutine function parameter not inserted into move map\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 580, __PRETTY_FUNCTION__))
;
581 // If a reference to the function parameter exists in the coroutine
582 // frame, use that reference.
583 auto *MoveDecl =
584 cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl());
585 RefExpr =
586 BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(),
587 ExprValueKind::VK_LValue, FD->getLocation());
588 if (RefExpr.isInvalid())
589 return nullptr;
590 CtorArgExprs.push_back(RefExpr.get());
591 }
592
593 // If we have a non-zero number of constructor arguments, try to use them.
594 // Otherwise, fall back to the promise type's default constructor.
595 if (!CtorArgExprs.empty()) {
596 // Create an initialization sequence for the promise type using the
597 // constructor arguments, wrapped in a parenthesized list expression.
598 Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(),
599 CtorArgExprs, FD->getLocation());
600 InitializedEntity Entity = InitializedEntity::InitializeVariable(VD);
601 InitializationKind Kind = InitializationKind::CreateForInit(
602 VD->getLocation(), /*DirectInit=*/true, PLE);
603 InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs,
604 /*TopLevelOfInitList=*/false,
605 /*TreatUnavailableAsInvalid=*/false);
606
607 // Attempt to initialize the promise type with the arguments.
608 // If that fails, fall back to the promise type's default constructor.
609 if (InitSeq) {
610 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs);
611 if (Result.isInvalid()) {
612 VD->setInvalidDecl();
613 } else if (Result.get()) {
614 VD->setInit(MaybeCreateExprWithCleanups(Result.get()));
615 VD->setInitStyle(VarDecl::CallInit);
616 CheckCompleteVariableDeclaration(VD);
617 }
618 } else
619 ActOnUninitializedDecl(VD);
620 } else
621 ActOnUninitializedDecl(VD);
622
623 FD->addDecl(VD);
624 return VD;
625}
626
627/// Check that this is a context in which a coroutine suspension can appear.
628static FunctionScopeInfo *checkCoroutineContext(Sema &S, SourceLocation Loc,
629 StringRef Keyword,
630 bool IsImplicit = false) {
631 if (!isValidCoroutineContext(S, Loc, Keyword))
632 return nullptr;
633
634 assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope")((isa<FunctionDecl>(S.CurContext) && "not in a function scope"
) ? static_cast<void> (0) : __assert_fail ("isa<FunctionDecl>(S.CurContext) && \"not in a function scope\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 634, __PRETTY_FUNCTION__))
;
635
636 auto *ScopeInfo = S.getCurFunction();
637 assert(ScopeInfo && "missing function scope for function")((ScopeInfo && "missing function scope for function")
? static_cast<void> (0) : __assert_fail ("ScopeInfo && \"missing function scope for function\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 637, __PRETTY_FUNCTION__))
;
638
639 if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit)
640 ScopeInfo->setFirstCoroutineStmt(Loc, Keyword);
641
642 if (ScopeInfo->CoroutinePromise)
643 return ScopeInfo;
644
645 if (!S.buildCoroutineParameterMoves(Loc))
646 return nullptr;
647
648 ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc);
649 if (!ScopeInfo->CoroutinePromise)
650 return nullptr;
651
652 return ScopeInfo;
653}
654
655/// Recursively check \p E and all its children to see if any call target
656/// (including constructor call) is declared noexcept. Also any value returned
657/// from the call has a noexcept destructor.
658static void checkNoThrow(Sema &S, const Stmt *E,
659 llvm::SmallPtrSetImpl<const Decl *> &ThrowingDecls) {
660 auto checkDeclNoexcept = [&](const Decl *D, bool IsDtor = false) {
661 // In the case of dtor, the call to dtor is implicit and hence we should
662 // pass nullptr to canCalleeThrow.
663 if (Sema::canCalleeThrow(S, IsDtor ? nullptr : cast<Expr>(E), D)) {
664 if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
665 // co_await promise.final_suspend() could end up calling
666 // __builtin_coro_resume for symmetric transfer if await_suspend()
667 // returns a handle. In that case, even __builtin_coro_resume is not
668 // declared as noexcept and may throw, it does not throw _into_ the
669 // coroutine that just suspended, but rather throws back out from
670 // whoever called coroutine_handle::resume(), hence we claim that
671 // logically it does not throw.
672 if (FD->getBuiltinID() == Builtin::BI__builtin_coro_resume)
673 return;
674 }
675 if (ThrowingDecls.empty()) {
676 // First time seeing an error, emit the error message.
677 S.Diag(cast<FunctionDecl>(S.CurContext)->getLocation(),
678 diag::err_coroutine_promise_final_suspend_requires_nothrow);
679 }
680 ThrowingDecls.insert(D);
681 }
682 };
683 auto SC = E->getStmtClass();
684 if (SC == Expr::CXXConstructExprClass) {
13
Assuming 'SC' is not equal to CXXConstructExprClass
14
Taking false branch
22
Assuming 'SC' is not equal to CXXConstructExprClass
23
Taking false branch
685 auto const *Ctor = cast<CXXConstructExpr>(E)->getConstructor();
686 checkDeclNoexcept(Ctor);
687 // Check the corresponding destructor of the constructor.
688 checkDeclNoexcept(Ctor->getParent()->getDestructor(), true);
689 } else if (SC == Expr::CallExprClass || SC == Expr::CXXMemberCallExprClass ||
15
Assuming 'SC' is not equal to CallExprClass
16
Assuming 'SC' is not equal to CXXMemberCallExprClass
18
Taking false branch
24
Assuming 'SC' is equal to CallExprClass
690 SC == Expr::CXXOperatorCallExprClass) {
17
Assuming 'SC' is not equal to CXXOperatorCallExprClass
691 if (!cast<CallExpr>(E)->isTypeDependent()) {
25
'E' is a 'CallExpr'
26
Assuming the condition is true
27
Taking true branch
692 checkDeclNoexcept(cast<CallExpr>(E)->getCalleeDecl());
28
'E' is a 'CallExpr'
693 auto ReturnType = cast<CallExpr>(E)->getCallReturnType(S.getASTContext());
29
'E' is a 'CallExpr'
694 // Check the destructor of the call return type, if any.
695 if (ReturnType.isDestructedType() ==
30
Assuming the condition is true
31
Taking true branch
696 QualType::DestructionKind::DK_cxx_destructor) {
697 const auto *T =
698 cast<RecordType>(ReturnType.getCanonicalType().getTypePtr());
32
The object is a 'RecordType'
699 checkDeclNoexcept(
700 dyn_cast<CXXRecordDecl>(T->getDecl())->getDestructor(), true);
33
Assuming the object is not a 'CXXRecordDecl'
34
Called C++ object pointer is null
701 }
702 }
703 }
704 for (const auto *Child : E->children()) {
705 if (!Child)
19
Assuming 'Child' is non-null
20
Taking false branch
706 continue;
707 checkNoThrow(S, Child, ThrowingDecls);
21
Calling 'checkNoThrow'
708 }
709}
710
711bool Sema::checkFinalSuspendNoThrow(const Stmt *FinalSuspend) {
712 llvm::SmallPtrSet<const Decl *, 4> ThrowingDecls;
713 // We first collect all declarations that should not throw but not declared
714 // with noexcept. We then sort them based on the location before printing.
715 // This is to avoid emitting the same note multiple times on the same
716 // declaration, and also provide a deterministic order for the messages.
717 checkNoThrow(*this, FinalSuspend, ThrowingDecls);
12
Calling 'checkNoThrow'
718 auto SortedDecls = llvm::SmallVector<const Decl *, 4>{ThrowingDecls.begin(),
719 ThrowingDecls.end()};
720 sort(SortedDecls, [](const Decl *A, const Decl *B) {
721 return A->getEndLoc() < B->getEndLoc();
722 });
723 for (const auto *D : SortedDecls) {
724 Diag(D->getEndLoc(), diag::note_coroutine_function_declare_noexcept);
725 }
726 return ThrowingDecls.empty();
727}
728
729bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc,
730 StringRef Keyword) {
731 if (!checkCoroutineContext(*this, KWLoc, Keyword))
2
Taking false branch
732 return false;
733 auto *ScopeInfo = getCurFunction();
734 assert(ScopeInfo->CoroutinePromise)((ScopeInfo->CoroutinePromise) ? static_cast<void> (
0) : __assert_fail ("ScopeInfo->CoroutinePromise", "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 734, __PRETTY_FUNCTION__))
;
3
Assuming field 'CoroutinePromise' is non-null
4
'?' condition is true
735
736 // If we have existing coroutine statements then we have already built
737 // the initial and final suspend points.
738 if (!ScopeInfo->NeedsCoroutineSuspends)
5
Assuming field 'NeedsCoroutineSuspends' is true
6
Taking false branch
739 return true;
740
741 ScopeInfo->setNeedsCoroutineSuspends(false);
742
743 auto *Fn = cast<FunctionDecl>(CurContext);
7
Field 'CurContext' is a 'FunctionDecl'
744 SourceLocation Loc = Fn->getLocation();
745 // Build the initial suspend point
746 auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
747 ExprResult Suspend =
748 buildPromiseCall(*this, ScopeInfo->CoroutinePromise, Loc, Name, None);
749 if (Suspend.isInvalid())
750 return StmtError();
751 Suspend = buildOperatorCoawaitCall(*this, SC, Loc, Suspend.get());
752 if (Suspend.isInvalid())
753 return StmtError();
754 Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),
755 /*IsImplicit*/ true);
756 Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
757 if (Suspend.isInvalid()) {
758 Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
759 << ((Name == "initial_suspend") ? 0 : 1);
760 Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
761 return StmtError();
762 }
763 return cast<Stmt>(Suspend.get());
764 };
765
766 StmtResult InitSuspend = buildSuspends("initial_suspend");
767 if (InitSuspend.isInvalid())
8
Assuming the condition is false
9
Taking false branch
768 return true;
769
770 StmtResult FinalSuspend = buildSuspends("final_suspend");
771 if (FinalSuspend.isInvalid() || !checkFinalSuspendNoThrow(FinalSuspend.get()))
10
Assuming the condition is false
11
Calling 'Sema::checkFinalSuspendNoThrow'
772 return true;
773
774 ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());
775
776 return true;
777}
778
779// Recursively walks up the scope hierarchy until either a 'catch' or a function
780// scope is found, whichever comes first.
781static bool isWithinCatchScope(Scope *S) {
782 // 'co_await' and 'co_yield' keywords are disallowed within catch blocks, but
783 // lambdas that use 'co_await' are allowed. The loop below ends when a
784 // function scope is found in order to ensure the following behavior:
785 //
786 // void foo() { // <- function scope
787 // try { //
788 // co_await x; // <- 'co_await' is OK within a function scope
789 // } catch { // <- catch scope
790 // co_await x; // <- 'co_await' is not OK within a catch scope
791 // []() { // <- function scope
792 // co_await x; // <- 'co_await' is OK within a function scope
793 // }();
794 // }
795 // }
796 while (S && !(S->getFlags() & Scope::FnScope)) {
797 if (S->getFlags() & Scope::CatchScope)
798 return true;
799 S = S->getParent();
800 }
801 return false;
802}
803
804// [expr.await]p2, emphasis added: "An await-expression shall appear only in
805// a *potentially evaluated* expression within the compound-statement of a
806// function-body *outside of a handler* [...] A context within a function
807// where an await-expression can appear is called a suspension context of the
808// function."
809static void checkSuspensionContext(Sema &S, SourceLocation Loc,
810 StringRef Keyword) {
811 // First emphasis of [expr.await]p2: must be a potentially evaluated context.
812 // That is, 'co_await' and 'co_yield' cannot appear in subexpressions of
813 // \c sizeof.
814 if (S.isUnevaluatedContext())
815 S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
816
817 // Second emphasis of [expr.await]p2: must be outside of an exception handler.
818 if (isWithinCatchScope(S.getCurScope()))
819 S.Diag(Loc, diag::err_coroutine_within_handler) << Keyword;
820}
821
822ExprResult Sema::ActOnCoawaitExpr(Scope *S, SourceLocation Loc, Expr *E) {
823 if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) {
824 CorrectDelayedTyposInExpr(E);
825 return ExprError();
826 }
827
828 checkSuspensionContext(*this, Loc, "co_await");
829
830 if (E->getType()->isPlaceholderType()) {
831 ExprResult R = CheckPlaceholderExpr(E);
832 if (R.isInvalid()) return ExprError();
833 E = R.get();
834 }
835 ExprResult Lookup = buildOperatorCoawaitLookupExpr(*this, S, Loc);
836 if (Lookup.isInvalid())
837 return ExprError();
838 return BuildUnresolvedCoawaitExpr(Loc, E,
839 cast<UnresolvedLookupExpr>(Lookup.get()));
840}
841
842ExprResult Sema::BuildUnresolvedCoawaitExpr(SourceLocation Loc, Expr *E,
843 UnresolvedLookupExpr *Lookup) {
844 auto *FSI = checkCoroutineContext(*this, Loc, "co_await");
845 if (!FSI)
846 return ExprError();
847
848 if (E->getType()->isPlaceholderType()) {
849 ExprResult R = CheckPlaceholderExpr(E);
850 if (R.isInvalid())
851 return ExprError();
852 E = R.get();
853 }
854
855 auto *Promise = FSI->CoroutinePromise;
856 if (Promise->getType()->isDependentType()) {
857 Expr *Res =
858 new (Context) DependentCoawaitExpr(Loc, Context.DependentTy, E, Lookup);
859 return Res;
860 }
861
862 auto *RD = Promise->getType()->getAsCXXRecordDecl();
863 if (lookupMember(*this, "await_transform", RD, Loc)) {
864 ExprResult R = buildPromiseCall(*this, Promise, Loc, "await_transform", E);
865 if (R.isInvalid()) {
866 Diag(Loc,
867 diag::note_coroutine_promise_implicit_await_transform_required_here)
868 << E->getSourceRange();
869 return ExprError();
870 }
871 E = R.get();
872 }
873 ExprResult Awaitable = buildOperatorCoawaitCall(*this, Loc, E, Lookup);
874 if (Awaitable.isInvalid())
875 return ExprError();
876
877 return BuildResolvedCoawaitExpr(Loc, Awaitable.get());
878}
879
880ExprResult Sema::BuildResolvedCoawaitExpr(SourceLocation Loc, Expr *E,
881 bool IsImplicit) {
882 auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit);
883 if (!Coroutine)
884 return ExprError();
885
886 if (E->getType()->isPlaceholderType()) {
887 ExprResult R = CheckPlaceholderExpr(E);
888 if (R.isInvalid()) return ExprError();
889 E = R.get();
890 }
891
892 if (E->getType()->isDependentType()) {
893 Expr *Res = new (Context)
894 CoawaitExpr(Loc, Context.DependentTy, E, IsImplicit);
895 return Res;
896 }
897
898 // If the expression is a temporary, materialize it as an lvalue so that we
899 // can use it multiple times.
900 if (E->getValueKind() == VK_RValue)
901 E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
902
903 // The location of the `co_await` token cannot be used when constructing
904 // the member call expressions since it's before the location of `Expr`, which
905 // is used as the start of the member call expression.
906 SourceLocation CallLoc = E->getExprLoc();
907
908 // Build the await_ready, await_suspend, await_resume calls.
909 ReadySuspendResumeResult RSS = buildCoawaitCalls(
910 *this, Coroutine->CoroutinePromise, CallLoc, E);
911 if (RSS.IsInvalid)
912 return ExprError();
913
914 Expr *Res =
915 new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
916 RSS.Results[2], RSS.OpaqueValue, IsImplicit);
917
918 return Res;
919}
920
921ExprResult Sema::ActOnCoyieldExpr(Scope *S, SourceLocation Loc, Expr *E) {
922 if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) {
923 CorrectDelayedTyposInExpr(E);
924 return ExprError();
925 }
926
927 checkSuspensionContext(*this, Loc, "co_yield");
928
929 // Build yield_value call.
930 ExprResult Awaitable = buildPromiseCall(
931 *this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E);
932 if (Awaitable.isInvalid())
933 return ExprError();
934
935 // Build 'operator co_await' call.
936 Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get());
937 if (Awaitable.isInvalid())
938 return ExprError();
939
940 return BuildCoyieldExpr(Loc, Awaitable.get());
941}
942ExprResult Sema::BuildCoyieldExpr(SourceLocation Loc, Expr *E) {
943 auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
944 if (!Coroutine)
945 return ExprError();
946
947 if (E->getType()->isPlaceholderType()) {
948 ExprResult R = CheckPlaceholderExpr(E);
949 if (R.isInvalid()) return ExprError();
950 E = R.get();
951 }
952
953 if (E->getType()->isDependentType()) {
954 Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, E);
955 return Res;
956 }
957
958 // If the expression is a temporary, materialize it as an lvalue so that we
959 // can use it multiple times.
960 if (E->getValueKind() == VK_RValue)
961 E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
962
963 // Build the await_ready, await_suspend, await_resume calls.
964 ReadySuspendResumeResult RSS = buildCoawaitCalls(
965 *this, Coroutine->CoroutinePromise, Loc, E);
966 if (RSS.IsInvalid)
967 return ExprError();
968
969 Expr *Res =
970 new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
971 RSS.Results[2], RSS.OpaqueValue);
972
973 return Res;
974}
975
976StmtResult Sema::ActOnCoreturnStmt(Scope *S, SourceLocation Loc, Expr *E) {
977 if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) {
1
Calling 'Sema::ActOnCoroutineBodyStart'
978 CorrectDelayedTyposInExpr(E);
979 return StmtError();
980 }
981 return BuildCoreturnStmt(Loc, E);
982}
983
984StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E,
985 bool IsImplicit) {
986 auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit);
987 if (!FSI)
988 return StmtError();
989
990 if (E && E->getType()->isPlaceholderType() &&
991 !E->getType()->isSpecificPlaceholderType(BuiltinType::Overload)) {
992 ExprResult R = CheckPlaceholderExpr(E);
993 if (R.isInvalid()) return StmtError();
994 E = R.get();
995 }
996
997 // Move the return value if we can
998 if (E) {
999 auto NRVOCandidate = this->getCopyElisionCandidate(E->getType(), E, CES_AsIfByStdMove);
1000 if (NRVOCandidate) {
1001 InitializedEntity Entity =
1002 InitializedEntity::InitializeResult(Loc, E->getType(), NRVOCandidate);
1003 ExprResult MoveResult = this->PerformMoveOrCopyInitialization(
1004 Entity, NRVOCandidate, E->getType(), E);
1005 if (MoveResult.get())
1006 E = MoveResult.get();
1007 }
1008 }
1009
1010 // FIXME: If the operand is a reference to a variable that's about to go out
1011 // of scope, we should treat the operand as an xvalue for this overload
1012 // resolution.
1013 VarDecl *Promise = FSI->CoroutinePromise;
1014 ExprResult PC;
1015 if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
1016 PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
1017 } else {
1018 E = MakeFullDiscardedValueExpr(E).get();
1019 PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
1020 }
1021 if (PC.isInvalid())
1022 return StmtError();
1023
1024 Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
1025
1026 Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
1027 return Res;
1028}
1029
1030/// Look up the std::nothrow object.
1031static Expr *buildStdNoThrowDeclRef(Sema &S, SourceLocation Loc) {
1032 NamespaceDecl *Std = S.getStdNamespace();
1033 assert(Std && "Should already be diagnosed")((Std && "Should already be diagnosed") ? static_cast
<void> (0) : __assert_fail ("Std && \"Should already be diagnosed\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1033, __PRETTY_FUNCTION__))
;
1034
1035 LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
1036 Sema::LookupOrdinaryName);
1037 if (!S.LookupQualifiedName(Result, Std)) {
1038 // FIXME: <experimental/coroutine> should have been included already.
1039 // If we require it to include <new> then this diagnostic is no longer
1040 // needed.
1041 S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
1042 return nullptr;
1043 }
1044
1045 auto *VD = Result.getAsSingle<VarDecl>();
1046 if (!VD) {
1047 Result.suppressDiagnostics();
1048 // We found something weird. Complain about the first thing we found.
1049 NamedDecl *Found = *Result.begin();
1050 S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
1051 return nullptr;
1052 }
1053
1054 ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
1055 if (DR.isInvalid())
1056 return nullptr;
1057
1058 return DR.get();
1059}
1060
1061// Find an appropriate delete for the promise.
1062static FunctionDecl *findDeleteForPromise(Sema &S, SourceLocation Loc,
1063 QualType PromiseType) {
1064 FunctionDecl *OperatorDelete = nullptr;
1065
1066 DeclarationName DeleteName =
1067 S.Context.DeclarationNames.getCXXOperatorName(OO_Delete);
1068
1069 auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
1070 assert(PointeeRD && "PromiseType must be a CxxRecordDecl type")((PointeeRD && "PromiseType must be a CxxRecordDecl type"
) ? static_cast<void> (0) : __assert_fail ("PointeeRD && \"PromiseType must be a CxxRecordDecl type\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1070, __PRETTY_FUNCTION__))
;
1071
1072 if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete))
1073 return nullptr;
1074
1075 if (!OperatorDelete) {
1076 // Look for a global declaration.
1077 const bool CanProvideSize = S.isCompleteType(Loc, PromiseType);
1078 const bool Overaligned = false;
1079 OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
1080 Overaligned, DeleteName);
1081 }
1082 S.MarkFunctionReferenced(Loc, OperatorDelete);
1083 return OperatorDelete;
1084}
1085
1086
1087void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) {
1088 FunctionScopeInfo *Fn = getCurFunction();
1089 assert(Fn && Fn->isCoroutine() && "not a coroutine")((Fn && Fn->isCoroutine() && "not a coroutine"
) ? static_cast<void> (0) : __assert_fail ("Fn && Fn->isCoroutine() && \"not a coroutine\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1089, __PRETTY_FUNCTION__))
;
1090 if (!Body) {
1091 assert(FD->isInvalidDecl() &&((FD->isInvalidDecl() && "a null body is only allowed for invalid declarations"
) ? static_cast<void> (0) : __assert_fail ("FD->isInvalidDecl() && \"a null body is only allowed for invalid declarations\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1092, __PRETTY_FUNCTION__))
1092 "a null body is only allowed for invalid declarations")((FD->isInvalidDecl() && "a null body is only allowed for invalid declarations"
) ? static_cast<void> (0) : __assert_fail ("FD->isInvalidDecl() && \"a null body is only allowed for invalid declarations\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1092, __PRETTY_FUNCTION__))
;
1093 return;
1094 }
1095 // We have a function that uses coroutine keywords, but we failed to build
1096 // the promise type.
1097 if (!Fn->CoroutinePromise)
1098 return FD->setInvalidDecl();
1099
1100 if (isa<CoroutineBodyStmt>(Body)) {
1101 // Nothing todo. the body is already a transformed coroutine body statement.
1102 return;
1103 }
1104
1105 // Coroutines [stmt.return]p1:
1106 // A return statement shall not appear in a coroutine.
1107 if (Fn->FirstReturnLoc.isValid()) {
1108 assert(Fn->FirstCoroutineStmtLoc.isValid() &&((Fn->FirstCoroutineStmtLoc.isValid() && "first coroutine location not set"
) ? static_cast<void> (0) : __assert_fail ("Fn->FirstCoroutineStmtLoc.isValid() && \"first coroutine location not set\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1109, __PRETTY_FUNCTION__))
1109 "first coroutine location not set")((Fn->FirstCoroutineStmtLoc.isValid() && "first coroutine location not set"
) ? static_cast<void> (0) : __assert_fail ("Fn->FirstCoroutineStmtLoc.isValid() && \"first coroutine location not set\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1109, __PRETTY_FUNCTION__))
;
1110 Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
1111 Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1112 << Fn->getFirstCoroutineStmtKeyword();
1113 }
1114 CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body);
1115 if (Builder.isInvalid() || !Builder.buildStatements())
1116 return FD->setInvalidDecl();
1117
1118 // Build body for the coroutine wrapper statement.
1119 Body = CoroutineBodyStmt::Create(Context, Builder);
1120}
1121
1122CoroutineStmtBuilder::CoroutineStmtBuilder(Sema &S, FunctionDecl &FD,
1123 sema::FunctionScopeInfo &Fn,
1124 Stmt *Body)
1125 : S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()),
1126 IsPromiseDependentType(
1127 !Fn.CoroutinePromise ||
1128 Fn.CoroutinePromise->getType()->isDependentType()) {
1129 this->Body = Body;
1130
1131 for (auto KV : Fn.CoroutineParameterMoves)
1132 this->ParamMovesVector.push_back(KV.second);
1133 this->ParamMoves = this->ParamMovesVector;
1134
1135 if (!IsPromiseDependentType) {
1136 PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl();
1137 assert(PromiseRecordDecl && "Type should have already been checked")((PromiseRecordDecl && "Type should have already been checked"
) ? static_cast<void> (0) : __assert_fail ("PromiseRecordDecl && \"Type should have already been checked\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1137, __PRETTY_FUNCTION__))
;
1138 }
1139 this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend();
1140}
1141
1142bool CoroutineStmtBuilder::buildStatements() {
1143 assert(this->IsValid && "coroutine already invalid")((this->IsValid && "coroutine already invalid") ? static_cast
<void> (0) : __assert_fail ("this->IsValid && \"coroutine already invalid\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1143, __PRETTY_FUNCTION__))
;
1144 this->IsValid = makeReturnObject();
1145 if (this->IsValid && !IsPromiseDependentType)
1146 buildDependentStatements();
1147 return this->IsValid;
1148}
1149
1150bool CoroutineStmtBuilder::buildDependentStatements() {
1151 assert(this->IsValid && "coroutine already invalid")((this->IsValid && "coroutine already invalid") ? static_cast
<void> (0) : __assert_fail ("this->IsValid && \"coroutine already invalid\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1151, __PRETTY_FUNCTION__))
;
1152 assert(!this->IsPromiseDependentType &&((!this->IsPromiseDependentType && "coroutine cannot have a dependent promise type"
) ? static_cast<void> (0) : __assert_fail ("!this->IsPromiseDependentType && \"coroutine cannot have a dependent promise type\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1153, __PRETTY_FUNCTION__))
1153 "coroutine cannot have a dependent promise type")((!this->IsPromiseDependentType && "coroutine cannot have a dependent promise type"
) ? static_cast<void> (0) : __assert_fail ("!this->IsPromiseDependentType && \"coroutine cannot have a dependent promise type\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1153, __PRETTY_FUNCTION__))
;
1154 this->IsValid = makeOnException() && makeOnFallthrough() &&
1155 makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
1156 makeNewAndDeleteExpr();
1157 return this->IsValid;
1158}
1159
1160bool CoroutineStmtBuilder::makePromiseStmt() {
1161 // Form a declaration statement for the promise declaration, so that AST
1162 // visitors can more easily find it.
1163 StmtResult PromiseStmt =
1164 S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(Fn.CoroutinePromise), Loc, Loc);
1165 if (PromiseStmt.isInvalid())
1166 return false;
1167
1168 this->Promise = PromiseStmt.get();
1169 return true;
1170}
1171
1172bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() {
1173 if (Fn.hasInvalidCoroutineSuspends())
1174 return false;
1175 this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first);
1176 this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second);
1177 return true;
1178}
1179
1180static bool diagReturnOnAllocFailure(Sema &S, Expr *E,
1181 CXXRecordDecl *PromiseRecordDecl,
1182 FunctionScopeInfo &Fn) {
1183 auto Loc = E->getExprLoc();
1184 if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) {
1185 auto *Decl = DeclRef->getDecl();
1186 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) {
1187 if (Method->isStatic())
1188 return true;
1189 else
1190 Loc = Decl->getLocation();
1191 }
1192 }
1193
1194 S.Diag(
1195 Loc,
1196 diag::err_coroutine_promise_get_return_object_on_allocation_failure)
1197 << PromiseRecordDecl;
1198 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1199 << Fn.getFirstCoroutineStmtKeyword();
1200 return false;
1201}
1202
1203bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
1204 assert(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1205, __PRETTY_FUNCTION__))
1205 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1205, __PRETTY_FUNCTION__))
;
1206
1207 // [dcl.fct.def.coroutine]/8
1208 // The unqualified-id get_return_object_on_allocation_failure is looked up in
1209 // the scope of class P by class member access lookup (3.4.5). ...
1210 // If an allocation function returns nullptr, ... the coroutine return value
1211 // is obtained by a call to ... get_return_object_on_allocation_failure().
1212
1213 DeclarationName DN =
1214 S.PP.getIdentifierInfo("get_return_object_on_allocation_failure");
1215 LookupResult Found(S, DN, Loc, Sema::LookupMemberName);
1216 if (!S.LookupQualifiedName(Found, PromiseRecordDecl))
1217 return true;
1218
1219 CXXScopeSpec SS;
1220 ExprResult DeclNameExpr =
1221 S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
1222 if (DeclNameExpr.isInvalid())
1223 return false;
1224
1225 if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn))
1226 return false;
1227
1228 ExprResult ReturnObjectOnAllocationFailure =
1229 S.BuildCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc);
1230 if (ReturnObjectOnAllocationFailure.isInvalid())
1231 return false;
1232
1233 StmtResult ReturnStmt =
1234 S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
1235 if (ReturnStmt.isInvalid()) {
1236 S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here)
1237 << DN;
1238 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1239 << Fn.getFirstCoroutineStmtKeyword();
1240 return false;
1241 }
1242
1243 this->ReturnStmtOnAllocFailure = ReturnStmt.get();
1244 return true;
1245}
1246
1247bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
1248 // Form and check allocation and deallocation calls.
1249 assert(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1250, __PRETTY_FUNCTION__))
1250 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1250, __PRETTY_FUNCTION__))
;
1251 QualType PromiseType = Fn.CoroutinePromise->getType();
1252
1253 if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
1254 return false;
1255
1256 const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
1257
1258 // [dcl.fct.def.coroutine]/7
1259 // Lookup allocation functions using a parameter list composed of the
1260 // requested size of the coroutine state being allocated, followed by
1261 // the coroutine function's arguments. If a matching allocation function
1262 // exists, use it. Otherwise, use an allocation function that just takes
1263 // the requested size.
1264
1265 FunctionDecl *OperatorNew = nullptr;
1266 FunctionDecl *OperatorDelete = nullptr;
1267 FunctionDecl *UnusedResult = nullptr;
1268 bool PassAlignment = false;
1269 SmallVector<Expr *, 1> PlacementArgs;
1270
1271 // [dcl.fct.def.coroutine]/7
1272 // "The allocation function’s name is looked up in the scope of P.
1273 // [...] If the lookup finds an allocation function in the scope of P,
1274 // overload resolution is performed on a function call created by assembling
1275 // an argument list. The first argument is the amount of space requested,
1276 // and has type std::size_t. The lvalues p1 ... pn are the succeeding
1277 // arguments."
1278 //
1279 // ...where "p1 ... pn" are defined earlier as:
1280 //
1281 // [dcl.fct.def.coroutine]/3
1282 // "For a coroutine f that is a non-static member function, let P1 denote the
1283 // type of the implicit object parameter (13.3.1) and P2 ... Pn be the types
1284 // of the function parameters; otherwise let P1 ... Pn be the types of the
1285 // function parameters. Let p1 ... pn be lvalues denoting those objects."
1286 if (auto *MD = dyn_cast<CXXMethodDecl>(&FD)) {
1287 if (MD->isInstance() && !isLambdaCallOperator(MD)) {
1288 ExprResult ThisExpr = S.ActOnCXXThis(Loc);
1289 if (ThisExpr.isInvalid())
1290 return false;
1291 ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
1292 if (ThisExpr.isInvalid())
1293 return false;
1294 PlacementArgs.push_back(ThisExpr.get());
1295 }
1296 }
1297 for (auto *PD : FD.parameters()) {
1298 if (PD->getType()->isDependentType())
1299 continue;
1300
1301 // Build a reference to the parameter.
1302 auto PDLoc = PD->getLocation();
1303 ExprResult PDRefExpr =
1304 S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(),
1305 ExprValueKind::VK_LValue, PDLoc);
1306 if (PDRefExpr.isInvalid())
1307 return false;
1308
1309 PlacementArgs.push_back(PDRefExpr.get());
1310 }
1311 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1312 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1313 /*isArray*/ false, PassAlignment, PlacementArgs,
1314 OperatorNew, UnusedResult, /*Diagnose*/ false);
1315
1316 // [dcl.fct.def.coroutine]/7
1317 // "If no matching function is found, overload resolution is performed again
1318 // on a function call created by passing just the amount of space required as
1319 // an argument of type std::size_t."
1320 if (!OperatorNew && !PlacementArgs.empty()) {
1321 PlacementArgs.clear();
1322 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1323 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1324 /*isArray*/ false, PassAlignment, PlacementArgs,
1325 OperatorNew, UnusedResult, /*Diagnose*/ false);
1326 }
1327
1328 // [dcl.fct.def.coroutine]/7
1329 // "The allocation function’s name is looked up in the scope of P. If this
1330 // lookup fails, the allocation function’s name is looked up in the global
1331 // scope."
1332 if (!OperatorNew) {
1333 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Global,
1334 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1335 /*isArray*/ false, PassAlignment, PlacementArgs,
1336 OperatorNew, UnusedResult);
1337 }
1338
1339 bool IsGlobalOverload =
1340 OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
1341 // If we didn't find a class-local new declaration and non-throwing new
1342 // was is required then we need to lookup the non-throwing global operator
1343 // instead.
1344 if (RequiresNoThrowAlloc && (!OperatorNew || IsGlobalOverload)) {
1345 auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
1346 if (!StdNoThrow)
1347 return false;
1348 PlacementArgs = {StdNoThrow};
1349 OperatorNew = nullptr;
1350 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Both,
1351 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1352 /*isArray*/ false, PassAlignment, PlacementArgs,
1353 OperatorNew, UnusedResult);
1354 }
1355
1356 if (!OperatorNew)
1357 return false;
1358
1359 if (RequiresNoThrowAlloc) {
1360 const auto *FT = OperatorNew->getType()->castAs<FunctionProtoType>();
1361 if (!FT->isNothrow(/*ResultIfDependent*/ false)) {
1362 S.Diag(OperatorNew->getLocation(),
1363 diag::err_coroutine_promise_new_requires_nothrow)
1364 << OperatorNew;
1365 S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
1366 << OperatorNew;
1367 return false;
1368 }
1369 }
1370
1371 if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr)
1372 return false;
1373
1374 Expr *FramePtr =
1375 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
1376
1377 Expr *FrameSize =
1378 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_size, {});
1379
1380 // Make new call.
1381
1382 ExprResult NewRef =
1383 S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
1384 if (NewRef.isInvalid())
1385 return false;
1386
1387 SmallVector<Expr *, 2> NewArgs(1, FrameSize);
1388 for (auto Arg : PlacementArgs)
1389 NewArgs.push_back(Arg);
1390
1391 ExprResult NewExpr =
1392 S.BuildCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
1393 NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
1394 if (NewExpr.isInvalid())
1395 return false;
1396
1397 // Make delete call.
1398
1399 QualType OpDeleteQualType = OperatorDelete->getType();
1400
1401 ExprResult DeleteRef =
1402 S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
1403 if (DeleteRef.isInvalid())
1404 return false;
1405
1406 Expr *CoroFree =
1407 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_free, {FramePtr});
1408
1409 SmallVector<Expr *, 2> DeleteArgs{CoroFree};
1410
1411 // Check if we need to pass the size.
1412 const auto *OpDeleteType =
1413 OpDeleteQualType.getTypePtr()->castAs<FunctionProtoType>();
1414 if (OpDeleteType->getNumParams() > 1)
1415 DeleteArgs.push_back(FrameSize);
1416
1417 ExprResult DeleteExpr =
1418 S.BuildCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
1419 DeleteExpr =
1420 S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
1421 if (DeleteExpr.isInvalid())
1422 return false;
1423
1424 this->Allocate = NewExpr.get();
1425 this->Deallocate = DeleteExpr.get();
1426
1427 return true;
1428}
1429
1430bool CoroutineStmtBuilder::makeOnFallthrough() {
1431 assert(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1432, __PRETTY_FUNCTION__))
1432 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1432, __PRETTY_FUNCTION__))
;
1433
1434 // [dcl.fct.def.coroutine]/4
1435 // The unqualified-ids 'return_void' and 'return_value' are looked up in
1436 // the scope of class P. If both are found, the program is ill-formed.
1437 bool HasRVoid, HasRValue;
1438 LookupResult LRVoid =
1439 lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid);
1440 LookupResult LRValue =
1441 lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue);
1442
1443 StmtResult Fallthrough;
1444 if (HasRVoid && HasRValue) {
1445 // FIXME Improve this diagnostic
1446 S.Diag(FD.getLocation(),
1447 diag::err_coroutine_promise_incompatible_return_functions)
1448 << PromiseRecordDecl;
1449 S.Diag(LRVoid.getRepresentativeDecl()->getLocation(),
1450 diag::note_member_first_declared_here)
1451 << LRVoid.getLookupName();
1452 S.Diag(LRValue.getRepresentativeDecl()->getLocation(),
1453 diag::note_member_first_declared_here)
1454 << LRValue.getLookupName();
1455 return false;
1456 } else if (!HasRVoid && !HasRValue) {
1457 // FIXME: The PDTS currently specifies this case as UB, not ill-formed.
1458 // However we still diagnose this as an error since until the PDTS is fixed.
1459 S.Diag(FD.getLocation(),
1460 diag::err_coroutine_promise_requires_return_function)
1461 << PromiseRecordDecl;
1462 S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1463 << PromiseRecordDecl;
1464 return false;
1465 } else if (HasRVoid) {
1466 // If the unqualified-id return_void is found, flowing off the end of a
1467 // coroutine is equivalent to a co_return with no operand. Otherwise,
1468 // flowing off the end of a coroutine results in undefined behavior.
1469 Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr,
1470 /*IsImplicit*/false);
1471 Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get());
1472 if (Fallthrough.isInvalid())
1473 return false;
1474 }
1475
1476 this->OnFallthrough = Fallthrough.get();
1477 return true;
1478}
1479
1480bool CoroutineStmtBuilder::makeOnException() {
1481 // Try to form 'p.unhandled_exception();'
1482 assert(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1483, __PRETTY_FUNCTION__))
1483 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1483, __PRETTY_FUNCTION__))
;
1484
1485 const bool RequireUnhandledException = S.getLangOpts().CXXExceptions;
1486
1487 if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) {
1488 auto DiagID =
1489 RequireUnhandledException
1490 ? diag::err_coroutine_promise_unhandled_exception_required
1491 : diag::
1492 warn_coroutine_promise_unhandled_exception_required_with_exceptions;
1493 S.Diag(Loc, DiagID) << PromiseRecordDecl;
1494 S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1495 << PromiseRecordDecl;
1496 return !RequireUnhandledException;
1497 }
1498
1499 // If exceptions are disabled, don't try to build OnException.
1500 if (!S.getLangOpts().CXXExceptions)
1501 return true;
1502
1503 ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
1504 "unhandled_exception", None);
1505 UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
1506 /*DiscardedValue*/ false);
1507 if (UnhandledException.isInvalid())
1508 return false;
1509
1510 // Since the body of the coroutine will be wrapped in try-catch, it will
1511 // be incompatible with SEH __try if present in a function.
1512 if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) {
1513 S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions);
1514 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1515 << Fn.getFirstCoroutineStmtKeyword();
1516 return false;
1517 }
1518
1519 this->OnException = UnhandledException.get();
1520 return true;
1521}
1522
1523bool CoroutineStmtBuilder::makeReturnObject() {
1524 // Build implicit 'p.get_return_object()' expression and form initialization
1525 // of return type from it.
1526 ExprResult ReturnObject =
1527 buildPromiseCall(S, Fn.CoroutinePromise, Loc, "get_return_object", None);
1528 if (ReturnObject.isInvalid())
1529 return false;
1530
1531 this->ReturnValue = ReturnObject.get();
1532 return true;
1533}
1534
1535static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn) {
1536 if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
1537 auto *MethodDecl = MbrRef->getMethodDecl();
1538 S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here)
1539 << MethodDecl;
1540 }
1541 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1542 << Fn.getFirstCoroutineStmtKeyword();
1543}
1544
1545bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
1546 assert(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1547, __PRETTY_FUNCTION__))
1547 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1547, __PRETTY_FUNCTION__))
;
1548 assert(this->ReturnValue && "ReturnValue must be already formed")((this->ReturnValue && "ReturnValue must be already formed"
) ? static_cast<void> (0) : __assert_fail ("this->ReturnValue && \"ReturnValue must be already formed\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1548, __PRETTY_FUNCTION__))
;
1549
1550 QualType const GroType = this->ReturnValue->getType();
1551 assert(!GroType->isDependentType() &&((!GroType->isDependentType() && "get_return_object type must no longer be dependent"
) ? static_cast<void> (0) : __assert_fail ("!GroType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1552, __PRETTY_FUNCTION__))
1552 "get_return_object type must no longer be dependent")((!GroType->isDependentType() && "get_return_object type must no longer be dependent"
) ? static_cast<void> (0) : __assert_fail ("!GroType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1552, __PRETTY_FUNCTION__))
;
1553
1554 QualType const FnRetType = FD.getReturnType();
1555 assert(!FnRetType->isDependentType() &&((!FnRetType->isDependentType() && "get_return_object type must no longer be dependent"
) ? static_cast<void> (0) : __assert_fail ("!FnRetType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1556, __PRETTY_FUNCTION__))
1556 "get_return_object type must no longer be dependent")((!FnRetType->isDependentType() && "get_return_object type must no longer be dependent"
) ? static_cast<void> (0) : __assert_fail ("!FnRetType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1556, __PRETTY_FUNCTION__))
;
1557
1558 if (FnRetType->isVoidType()) {
1559 ExprResult Res =
1560 S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
1561 if (Res.isInvalid())
1562 return false;
1563
1564 this->ResultDecl = Res.get();
1565 return true;
1566 }
1567
1568 if (GroType->isVoidType()) {
1569 // Trigger a nice error message.
1570 InitializedEntity Entity =
1571 InitializedEntity::InitializeResult(Loc, FnRetType, false);
1572 S.PerformMoveOrCopyInitialization(Entity, nullptr, FnRetType, ReturnValue);
1573 noteMemberDeclaredHere(S, ReturnValue, Fn);
1574 return false;
1575 }
1576
1577 auto *GroDecl = VarDecl::Create(
1578 S.Context, &FD, FD.getLocation(), FD.getLocation(),
1579 &S.PP.getIdentifierTable().get("__coro_gro"), GroType,
1580 S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
1581 GroDecl->setImplicit();
1582
1583 S.CheckVariableDeclarationType(GroDecl);
1584 if (GroDecl->isInvalidDecl())
1585 return false;
1586
1587 InitializedEntity Entity = InitializedEntity::InitializeVariable(GroDecl);
1588 ExprResult Res = S.PerformMoveOrCopyInitialization(Entity, nullptr, GroType,
1589 this->ReturnValue);
1590 if (Res.isInvalid())
1591 return false;
1592
1593 Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
1594 if (Res.isInvalid())
1595 return false;
1596
1597 S.AddInitializerToDecl(GroDecl, Res.get(),
1598 /*DirectInit=*/false);
1599
1600 S.FinalizeDeclaration(GroDecl);
1601
1602 // Form a declaration statement for the return declaration, so that AST
1603 // visitors can more easily find it.
1604 StmtResult GroDeclStmt =
1605 S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
1606 if (GroDeclStmt.isInvalid())
1607 return false;
1608
1609 this->ResultDecl = GroDeclStmt.get();
1610
1611 ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
1612 if (declRef.isInvalid())
1613 return false;
1614
1615 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
1616 if (ReturnStmt.isInvalid()) {
1617 noteMemberDeclaredHere(S, ReturnValue, Fn);
1618 return false;
1619 }
1620 if (cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl)
1621 GroDecl->setNRVOVariable(true);
1622
1623 this->ReturnStmt = ReturnStmt.get();
1624 return true;
1625}
1626
1627// Create a static_cast\<T&&>(expr).
1628static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) {
1629 if (T.isNull())
1630 T = E->getType();
1631 QualType TargetType = S.BuildReferenceType(
1632 T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName());
1633 SourceLocation ExprLoc = E->getBeginLoc();
1634 TypeSourceInfo *TargetLoc =
1635 S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc);
1636
1637 return S
1638 .BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
1639 SourceRange(ExprLoc, ExprLoc), E->getSourceRange())
1640 .get();
1641}
1642
1643/// Build a variable declaration for move parameter.
1644static VarDecl *buildVarDecl(Sema &S, SourceLocation Loc, QualType Type,
1645 IdentifierInfo *II) {
1646 TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc);
1647 VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type,
1648 TInfo, SC_None);
1649 Decl->setImplicit();
1650 return Decl;
1651}
1652
1653// Build statements that move coroutine function parameters to the coroutine
1654// frame, and store them on the function scope info.
1655bool Sema::buildCoroutineParameterMoves(SourceLocation Loc) {
1656 assert(isa<FunctionDecl>(CurContext) && "not in a function scope")((isa<FunctionDecl>(CurContext) && "not in a function scope"
) ? static_cast<void> (0) : __assert_fail ("isa<FunctionDecl>(CurContext) && \"not in a function scope\""
, "/build/llvm-toolchain-snapshot-12~++20210114111115+2b1e25befefc/clang/lib/Sema/SemaCoroutine.cpp"
, 1656, __PRETTY_FUNCTION__))
;
1657 auto *FD = cast<FunctionDecl>(CurContext);
1658
1659 auto *ScopeInfo = getCurFunction();
1660 if (!ScopeInfo->CoroutineParameterMoves.empty())
1661 return false;
1662
1663 for (auto *PD : FD->parameters()) {
1664 if (PD->getType()->isDependentType())
1665 continue;
1666
1667 ExprResult PDRefExpr =
1668 BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(),
1669 ExprValueKind::VK_LValue, Loc); // FIXME: scope?
1670 if (PDRefExpr.isInvalid())
1671 return false;
1672
1673 Expr *CExpr = nullptr;
1674 if (PD->getType()->getAsCXXRecordDecl() ||
1675 PD->getType()->isRValueReferenceType())
1676 CExpr = castForMoving(*this, PDRefExpr.get());
1677 else
1678 CExpr = PDRefExpr.get();
1679
1680 auto D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier());
1681 AddInitializerToDecl(D, CExpr, /*DirectInit=*/true);
1682
1683 // Convert decl to a statement.
1684 StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc);
1685 if (Stmt.isInvalid())
1686 return false;
1687
1688 ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get()));
1689 }
1690 return true;
1691}
1692
1693StmtResult Sema::BuildCoroutineBodyStmt(CoroutineBodyStmt::CtorArgs Args) {
1694 CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args);
1695 if (!Res)
1696 return StmtError();
1697 return Res;
1698}
1699
1700ClassTemplateDecl *Sema::lookupCoroutineTraits(SourceLocation KwLoc,
1701 SourceLocation FuncLoc) {
1702 if (!StdCoroutineTraitsCache) {
1703 if (auto StdExp = lookupStdExperimentalNamespace()) {
1704 LookupResult Result(*this,
1705 &PP.getIdentifierTable().get("coroutine_traits"),
1706 FuncLoc, LookupOrdinaryName);
1707 if (!LookupQualifiedName(Result, StdExp)) {
1708 Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
1709 << "std::experimental::coroutine_traits";
1710 return nullptr;
1711 }
1712 if (!(StdCoroutineTraitsCache =
1713 Result.getAsSingle<ClassTemplateDecl>())) {
1714 Result.suppressDiagnostics();
1715 NamedDecl *Found = *Result.begin();
1716 Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits);
1717 return nullptr;
1718 }
1719 }
1720 }
1721 return StdCoroutineTraitsCache;
1722}