/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/Sema/SemaCoroutine.cpp
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1 | | //===-- SemaCoroutine.cpp - Semantic Analysis for Coroutines --------------===// |
2 | | // |
3 | | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | | // See https://llvm.org/LICENSE.txt for license information. |
5 | | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | | // |
7 | | //===----------------------------------------------------------------------===// |
8 | | // |
9 | | // This file implements semantic analysis for C++ Coroutines. |
10 | | // |
11 | | // This file contains references to sections of the Coroutines TS, which |
12 | | // can be found at http://wg21.link/coroutines. |
13 | | // |
14 | | //===----------------------------------------------------------------------===// |
15 | | |
16 | | #include "CoroutineStmtBuilder.h" |
17 | | #include "clang/AST/ASTLambda.h" |
18 | | #include "clang/AST/Decl.h" |
19 | | #include "clang/AST/ExprCXX.h" |
20 | | #include "clang/AST/StmtCXX.h" |
21 | | #include "clang/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 | | |
29 | | using namespace clang; |
30 | | using namespace sema; |
31 | | |
32 | | static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD, |
33 | 1.50k | SourceLocation Loc, bool &Res) { |
34 | 1.50k | DeclarationName DN = S.PP.getIdentifierInfo(Name); |
35 | 1.50k | 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 | 1.50k | LR.suppressDiagnostics(); |
39 | 1.50k | Res = S.LookupQualifiedName(LR, RD); |
40 | 1.50k | return LR; |
41 | 1.50k | } |
42 | | |
43 | | static bool lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD, |
44 | 650 | SourceLocation Loc) { |
45 | 650 | bool Res; |
46 | 650 | lookupMember(S, Name, RD, Loc, Res); |
47 | 650 | return Res; |
48 | 650 | } |
49 | | |
50 | | /// Look up the std::coroutine_traits<...>::promise_type for the given |
51 | | /// function type. |
52 | | static QualType lookupPromiseType(Sema &S, const FunctionDecl *FD, |
53 | 506 | SourceLocation KwLoc) { |
54 | 506 | const FunctionProtoType *FnType = FD->getType()->castAs<FunctionProtoType>(); |
55 | 506 | const SourceLocation FuncLoc = FD->getLocation(); |
56 | | |
57 | 506 | ClassTemplateDecl *CoroTraits = |
58 | 506 | S.lookupCoroutineTraits(KwLoc, FuncLoc); |
59 | 506 | if (!CoroTraits) |
60 | 8 | return QualType(); |
61 | | |
62 | | // Form template argument list for coroutine_traits<R, P1, P2, ...> according |
63 | | // to [dcl.fct.def.coroutine]3 |
64 | 498 | TemplateArgumentListInfo Args(KwLoc, KwLoc); |
65 | 929 | auto AddArg = [&](QualType T) { |
66 | 929 | Args.addArgument(TemplateArgumentLoc( |
67 | 929 | TemplateArgument(T), S.Context.getTrivialTypeSourceInfo(T, KwLoc))); |
68 | 929 | }; |
69 | 498 | AddArg(FnType->getReturnType()); |
70 | | // If the function is a non-static member function, add the type |
71 | | // of the implicit object parameter before the formal parameters. |
72 | 498 | if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) { |
73 | 126 | if (MD->isImplicitObjectMemberFunction()) { |
74 | | // [over.match.funcs]4 |
75 | | // For non-static member functions, the type of the implicit object |
76 | | // parameter is |
77 | | // -- "lvalue reference to cv X" for functions declared without a |
78 | | // ref-qualifier or with the & ref-qualifier |
79 | | // -- "rvalue reference to cv X" for functions declared with the && |
80 | | // ref-qualifier |
81 | 97 | QualType T = MD->getFunctionObjectParameterType(); |
82 | 97 | T = FnType->getRefQualifier() == RQ_RValue |
83 | 97 | ? S.Context.getRValueReferenceType(T)15 |
84 | 97 | : S.Context.getLValueReferenceType(T, /*SpelledAsLValue*/ true)82 ; |
85 | 97 | AddArg(T); |
86 | 97 | } |
87 | 126 | } |
88 | 498 | for (QualType T : FnType->getParamTypes()) |
89 | 334 | AddArg(T); |
90 | | |
91 | | // Build the template-id. |
92 | 498 | QualType CoroTrait = |
93 | 498 | S.CheckTemplateIdType(TemplateName(CoroTraits), KwLoc, Args); |
94 | 498 | if (CoroTrait.isNull()) |
95 | 0 | return QualType(); |
96 | 498 | if (S.RequireCompleteType(KwLoc, CoroTrait, |
97 | 498 | diag::err_coroutine_type_missing_specialization)) |
98 | 2 | return QualType(); |
99 | | |
100 | 496 | auto *RD = CoroTrait->getAsCXXRecordDecl(); |
101 | 496 | assert(RD && "specialization of class template is not a class?"); |
102 | | |
103 | | // Look up the ::promise_type member. |
104 | 496 | LookupResult R(S, &S.PP.getIdentifierTable().get("promise_type"), KwLoc, |
105 | 496 | Sema::LookupOrdinaryName); |
106 | 496 | S.LookupQualifiedName(R, RD); |
107 | 496 | auto *Promise = R.getAsSingle<TypeDecl>(); |
108 | 496 | if (!Promise) { |
109 | 12 | S.Diag(FuncLoc, |
110 | 12 | diag::err_implied_std_coroutine_traits_promise_type_not_found) |
111 | 12 | << RD; |
112 | 12 | return QualType(); |
113 | 12 | } |
114 | | // The promise type is required to be a class type. |
115 | 484 | QualType PromiseType = S.Context.getTypeDeclType(Promise); |
116 | | |
117 | 484 | auto buildElaboratedType = [&]() { |
118 | 484 | auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, S.getStdNamespace()); |
119 | 484 | NNS = NestedNameSpecifier::Create(S.Context, NNS, false, |
120 | 484 | CoroTrait.getTypePtr()); |
121 | 484 | return S.Context.getElaboratedType(ElaboratedTypeKeyword::None, NNS, |
122 | 484 | PromiseType); |
123 | 484 | }; |
124 | | |
125 | 484 | if (!PromiseType->getAsCXXRecordDecl()) { |
126 | 2 | S.Diag(FuncLoc, |
127 | 2 | diag::err_implied_std_coroutine_traits_promise_type_not_class) |
128 | 2 | << buildElaboratedType(); |
129 | 2 | return QualType(); |
130 | 2 | } |
131 | 482 | if (S.RequireCompleteType(FuncLoc, buildElaboratedType(), |
132 | 482 | diag::err_coroutine_promise_type_incomplete)) |
133 | 2 | return QualType(); |
134 | | |
135 | 480 | return PromiseType; |
136 | 482 | } |
137 | | |
138 | | /// Look up the std::coroutine_handle<PromiseType>. |
139 | | static QualType lookupCoroutineHandleType(Sema &S, QualType PromiseType, |
140 | 1.23k | SourceLocation Loc) { |
141 | 1.23k | if (PromiseType.isNull()) |
142 | 0 | return QualType(); |
143 | | |
144 | 1.23k | NamespaceDecl *CoroNamespace = S.getStdNamespace(); |
145 | 1.23k | assert(CoroNamespace && "Should already be diagnosed"); |
146 | | |
147 | 1.23k | LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_handle"), |
148 | 1.23k | Loc, Sema::LookupOrdinaryName); |
149 | 1.23k | if (!S.LookupQualifiedName(Result, CoroNamespace)) { |
150 | 2 | S.Diag(Loc, diag::err_implied_coroutine_type_not_found) |
151 | 2 | << "std::coroutine_handle"; |
152 | 2 | return QualType(); |
153 | 2 | } |
154 | | |
155 | 1.23k | ClassTemplateDecl *CoroHandle = Result.getAsSingle<ClassTemplateDecl>(); |
156 | 1.23k | if (!CoroHandle) { |
157 | 0 | Result.suppressDiagnostics(); |
158 | | // We found something weird. Complain about the first thing we found. |
159 | 0 | NamedDecl *Found = *Result.begin(); |
160 | 0 | S.Diag(Found->getLocation(), diag::err_malformed_std_coroutine_handle); |
161 | 0 | return QualType(); |
162 | 0 | } |
163 | | |
164 | | // Form template argument list for coroutine_handle<Promise>. |
165 | 1.23k | TemplateArgumentListInfo Args(Loc, Loc); |
166 | 1.23k | Args.addArgument(TemplateArgumentLoc( |
167 | 1.23k | TemplateArgument(PromiseType), |
168 | 1.23k | S.Context.getTrivialTypeSourceInfo(PromiseType, Loc))); |
169 | | |
170 | | // Build the template-id. |
171 | 1.23k | QualType CoroHandleType = |
172 | 1.23k | S.CheckTemplateIdType(TemplateName(CoroHandle), Loc, Args); |
173 | 1.23k | if (CoroHandleType.isNull()) |
174 | 0 | return QualType(); |
175 | 1.23k | if (S.RequireCompleteType(Loc, CoroHandleType, |
176 | 1.23k | diag::err_coroutine_type_missing_specialization)) |
177 | 0 | return QualType(); |
178 | | |
179 | 1.23k | return CoroHandleType; |
180 | 1.23k | } |
181 | | |
182 | | static bool isValidCoroutineContext(Sema &S, SourceLocation Loc, |
183 | 2.94k | StringRef Keyword) { |
184 | | // [expr.await]p2 dictates that 'co_await' and 'co_yield' must be used within |
185 | | // a function body. |
186 | | // FIXME: This also covers [expr.await]p2: "An await-expression shall not |
187 | | // appear in a default argument." But the diagnostic QoI here could be |
188 | | // improved to inform the user that default arguments specifically are not |
189 | | // allowed. |
190 | 2.94k | auto *FD = dyn_cast<FunctionDecl>(S.CurContext); |
191 | 2.94k | if (!FD) { |
192 | 2 | S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext) |
193 | 2 | ? diag::err_coroutine_objc_method0 |
194 | 2 | : diag::err_coroutine_outside_function) << Keyword; |
195 | 2 | return false; |
196 | 2 | } |
197 | | |
198 | | // An enumeration for mapping the diagnostic type to the correct diagnostic |
199 | | // selection index. |
200 | 2.94k | enum InvalidFuncDiag { |
201 | 2.94k | DiagCtor = 0, |
202 | 2.94k | DiagDtor, |
203 | 2.94k | DiagMain, |
204 | 2.94k | DiagConstexpr, |
205 | 2.94k | DiagAutoRet, |
206 | 2.94k | DiagVarargs, |
207 | 2.94k | DiagConsteval, |
208 | 2.94k | }; |
209 | 2.94k | bool Diagnosed = false; |
210 | 2.94k | auto DiagInvalid = [&](InvalidFuncDiag ID) { |
211 | 17 | S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword; |
212 | 17 | Diagnosed = true; |
213 | 17 | return false; |
214 | 17 | }; |
215 | | |
216 | | // Diagnose when a constructor, destructor |
217 | | // or the function 'main' are declared as a coroutine. |
218 | 2.94k | auto *MD = dyn_cast<CXXMethodDecl>(FD); |
219 | | // [class.ctor]p11: "A constructor shall not be a coroutine." |
220 | 2.94k | if (MD && isa<CXXConstructorDecl>(MD)751 ) |
221 | 4 | return DiagInvalid(DiagCtor); |
222 | | // [class.dtor]p17: "A destructor shall not be a coroutine." |
223 | 2.94k | else if (MD && isa<CXXDestructorDecl>(MD)747 ) |
224 | 2 | return DiagInvalid(DiagDtor); |
225 | | // [basic.start.main]p3: "The function main shall not be a coroutine." |
226 | 2.93k | else if (FD->isMain()) |
227 | 2 | return DiagInvalid(DiagMain); |
228 | | |
229 | | // Emit a diagnostics for each of the following conditions which is not met. |
230 | | // [expr.const]p2: "An expression e is a core constant expression unless the |
231 | | // evaluation of e [...] would evaluate one of the following expressions: |
232 | | // [...] an await-expression [...] a yield-expression." |
233 | 2.93k | if (FD->isConstexpr()) |
234 | 3 | DiagInvalid(FD->isConsteval() ? DiagConsteval0 : DiagConstexpr); |
235 | | // [dcl.spec.auto]p15: "A function declared with a return type that uses a |
236 | | // placeholder type shall not be a coroutine." |
237 | 2.93k | if (FD->getReturnType()->isUndeducedType()) |
238 | 4 | DiagInvalid(DiagAutoRet); |
239 | | // [dcl.fct.def.coroutine]p1 |
240 | | // The parameter-declaration-clause of the coroutine shall not terminate with |
241 | | // an ellipsis that is not part of a parameter-declaration. |
242 | 2.93k | if (FD->isVariadic()) |
243 | 2 | DiagInvalid(DiagVarargs); |
244 | | |
245 | 2.93k | return !Diagnosed; |
246 | 2.94k | } |
247 | | |
248 | | /// Build a call to 'operator co_await' if there is a suitable operator for |
249 | | /// the given expression. |
250 | | ExprResult Sema::BuildOperatorCoawaitCall(SourceLocation Loc, Expr *E, |
251 | 1.47k | UnresolvedLookupExpr *Lookup) { |
252 | 1.47k | UnresolvedSet<16> Functions; |
253 | 1.47k | Functions.append(Lookup->decls_begin(), Lookup->decls_end()); |
254 | 1.47k | return CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E); |
255 | 1.47k | } |
256 | | |
257 | | static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, Scope *S, |
258 | 1.04k | SourceLocation Loc, Expr *E) { |
259 | 1.04k | ExprResult R = SemaRef.BuildOperatorCoawaitLookupExpr(S, Loc); |
260 | 1.04k | if (R.isInvalid()) |
261 | 0 | return ExprError(); |
262 | 1.04k | return SemaRef.BuildOperatorCoawaitCall(Loc, E, |
263 | 1.04k | cast<UnresolvedLookupExpr>(R.get())); |
264 | 1.04k | } |
265 | | |
266 | | static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType, |
267 | 1.23k | SourceLocation Loc) { |
268 | 1.23k | QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc); |
269 | 1.23k | if (CoroHandleType.isNull()) |
270 | 2 | return ExprError(); |
271 | | |
272 | 1.23k | DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType); |
273 | 1.23k | LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc, |
274 | 1.23k | Sema::LookupOrdinaryName); |
275 | 1.23k | if (!S.LookupQualifiedName(Found, LookupCtx)) { |
276 | 2 | S.Diag(Loc, diag::err_coroutine_handle_missing_member) |
277 | 2 | << "from_address"; |
278 | 2 | return ExprError(); |
279 | 2 | } |
280 | | |
281 | 1.22k | Expr *FramePtr = |
282 | 1.22k | S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_frame, {}); |
283 | | |
284 | 1.22k | CXXScopeSpec SS; |
285 | 1.22k | ExprResult FromAddr = |
286 | 1.22k | S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false); |
287 | 1.22k | if (FromAddr.isInvalid()) |
288 | 0 | return ExprError(); |
289 | | |
290 | 1.22k | return S.BuildCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc); |
291 | 1.22k | } |
292 | | |
293 | | struct ReadySuspendResumeResult { |
294 | | enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume }; |
295 | | Expr *Results[3]; |
296 | | OpaqueValueExpr *OpaqueValue; |
297 | | bool IsInvalid; |
298 | | }; |
299 | | |
300 | | static ExprResult buildMemberCall(Sema &S, Expr *Base, SourceLocation Loc, |
301 | 6.09k | StringRef Name, MultiExprArg Args) { |
302 | 6.09k | DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc); |
303 | | |
304 | | // FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&. |
305 | 6.09k | CXXScopeSpec SS; |
306 | 6.09k | ExprResult Result = S.BuildMemberReferenceExpr( |
307 | 6.09k | Base, Base->getType(), Loc, /*IsPtr=*/false, SS, |
308 | 6.09k | SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr, |
309 | 6.09k | /*Scope=*/nullptr); |
310 | 6.09k | if (Result.isInvalid()) |
311 | 39 | return ExprError(); |
312 | | |
313 | | // We meant exactly what we asked for. No need for typo correction. |
314 | 6.05k | if (auto *TE = dyn_cast<TypoExpr>(Result.get())) { |
315 | 6 | S.clearDelayedTypo(TE); |
316 | 6 | S.Diag(Loc, diag::err_no_member) |
317 | 6 | << NameInfo.getName() << Base->getType()->getAsCXXRecordDecl() |
318 | 6 | << Base->getSourceRange(); |
319 | 6 | return ExprError(); |
320 | 6 | } |
321 | | |
322 | 6.04k | auto EndLoc = Args.empty() ? Loc4.54k : Args.back()->getEndLoc()1.50k ; |
323 | 6.04k | return S.BuildCallExpr(nullptr, Result.get(), Loc, Args, EndLoc, nullptr); |
324 | 6.05k | } |
325 | | |
326 | | // See if return type is coroutine-handle and if so, invoke builtin coro-resume |
327 | | // on its address. This is to enable the support for coroutine-handle |
328 | | // returning await_suspend that results in a guaranteed tail call to the target |
329 | | // coroutine. |
330 | | static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E, |
331 | 1.22k | SourceLocation Loc) { |
332 | 1.22k | if (RetType->isReferenceType()) |
333 | 4 | return nullptr; |
334 | 1.22k | Type const *T = RetType.getTypePtr(); |
335 | 1.22k | if (!T->isClassType() && !T->isStructureType()) |
336 | 1.18k | return nullptr; |
337 | | |
338 | | // FIXME: Add convertability check to coroutine_handle<>. Possibly via |
339 | | // EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment |
340 | | // a private function in SemaExprCXX.cpp |
341 | | |
342 | 36 | ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", std::nullopt); |
343 | 36 | if (AddressExpr.isInvalid()) |
344 | 0 | return nullptr; |
345 | | |
346 | 36 | Expr *JustAddress = AddressExpr.get(); |
347 | | |
348 | | // FIXME: Without optimizations, the temporary result from `await_suspend()` |
349 | | // may be put on the coroutine frame since the coroutine frame constructor |
350 | | // will think the temporary variable will escape from the |
351 | | // `coroutine_handle<>::address()` call. This is problematic since the |
352 | | // coroutine should be considered to be suspended after it enters |
353 | | // `await_suspend` so it shouldn't access/update the coroutine frame after |
354 | | // that. |
355 | | // |
356 | | // See https://github.com/llvm/llvm-project/issues/65054 for the report. |
357 | | // |
358 | | // The long term solution may wrap the whole logic about `await-suspend` |
359 | | // into a standalone function. This is similar to the proposed solution |
360 | | // in tryMarkAwaitSuspendNoInline. See the comments there for details. |
361 | | // |
362 | | // The short term solution here is to mark `coroutine_handle<>::address()` |
363 | | // function as always-inline so that the coroutine frame constructor won't |
364 | | // think the temporary result is escaped incorrectly. |
365 | 36 | if (auto *FD = cast<CallExpr>(JustAddress)->getDirectCallee()) |
366 | 36 | if (!FD->hasAttr<AlwaysInlineAttr>() && !FD->hasAttr<NoInlineAttr>()18 ) |
367 | 18 | FD->addAttr(AlwaysInlineAttr::CreateImplicit(S.getASTContext(), |
368 | 18 | FD->getLocation())); |
369 | | |
370 | | // Check that the type of AddressExpr is void* |
371 | 36 | if (!JustAddress->getType().getTypePtr()->isVoidPointerType()) |
372 | 1 | S.Diag(cast<CallExpr>(JustAddress)->getCalleeDecl()->getLocation(), |
373 | 1 | diag::warn_coroutine_handle_address_invalid_return_type) |
374 | 1 | << JustAddress->getType(); |
375 | | |
376 | | // Clean up temporary objects so that they don't live across suspension points |
377 | | // unnecessarily. We choose to clean up before the call to |
378 | | // __builtin_coro_resume so that the cleanup code are not inserted in-between |
379 | | // the resume call and return instruction, which would interfere with the |
380 | | // musttail call contract. |
381 | 36 | JustAddress = S.MaybeCreateExprWithCleanups(JustAddress); |
382 | 36 | return S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_resume, |
383 | 36 | JustAddress); |
384 | 36 | } |
385 | | |
386 | | /// The await_suspend call performed by co_await is essentially asynchronous |
387 | | /// to the execution of the coroutine. Inlining it normally into an unsplit |
388 | | /// coroutine can cause miscompilation because the coroutine CFG misrepresents |
389 | | /// the true control flow of the program: things that happen in the |
390 | | /// await_suspend are not guaranteed to happen prior to the resumption of the |
391 | | /// coroutine, and things that happen after the resumption of the coroutine |
392 | | /// (including its exit and the potential deallocation of the coroutine frame) |
393 | | /// are not guaranteed to happen only after the end of await_suspend. |
394 | | /// |
395 | | /// See https://github.com/llvm/llvm-project/issues/56301 and |
396 | | /// https://reviews.llvm.org/D157070 for the example and the full discussion. |
397 | | /// |
398 | | /// The short-term solution to this problem is to mark the call as uninlinable. |
399 | | /// But we don't want to do this if the call is known to be trivial, which is |
400 | | /// very common. |
401 | | /// |
402 | | /// The long-term solution may introduce patterns like: |
403 | | /// |
404 | | /// call @llvm.coro.await_suspend(ptr %awaiter, ptr %handle, |
405 | | /// ptr @awaitSuspendFn) |
406 | | /// |
407 | | /// Then it is much easier to perform the safety analysis in the middle end. |
408 | | /// If it is safe to inline the call to awaitSuspend, we can replace it in the |
409 | | /// CoroEarly pass. Otherwise we could replace it in the CoroSplit pass. |
410 | | static void tryMarkAwaitSuspendNoInline(Sema &S, OpaqueValueExpr *Awaiter, |
411 | 1.22k | CallExpr *AwaitSuspend) { |
412 | | // The method here to extract the awaiter decl is not precise. |
413 | | // This is intentional. Since it is hard to perform the analysis in the |
414 | | // frontend due to the complexity of C++'s type systems. |
415 | | // And we prefer to perform such analysis in the middle end since it is |
416 | | // easier to implement and more powerful. |
417 | 1.22k | CXXRecordDecl *AwaiterDecl = |
418 | 1.22k | Awaiter->getType().getNonReferenceType()->getAsCXXRecordDecl(); |
419 | | |
420 | 1.22k | if (AwaiterDecl && AwaiterDecl->field_empty()) |
421 | 1.19k | return; |
422 | | |
423 | 29 | FunctionDecl *FD = AwaitSuspend->getDirectCallee(); |
424 | | |
425 | 29 | assert(FD); |
426 | | |
427 | | // If the `await_suspend()` function is marked as `always_inline` explicitly, |
428 | | // we should give the user the right to control the codegen. |
429 | 29 | if (FD->hasAttr<NoInlineAttr>() || FD->hasAttr<AlwaysInlineAttr>()17 ) |
430 | 13 | return; |
431 | | |
432 | | // This is problematic if the user calls the await_suspend standalone. But on |
433 | | // the on hand, it is not incorrect semantically since inlining is not part |
434 | | // of the standard. On the other hand, it is relatively rare to call |
435 | | // the await_suspend function standalone. |
436 | | // |
437 | | // And given we've already had the long-term plan, the current workaround |
438 | | // looks relatively tolerant. |
439 | 16 | FD->addAttr( |
440 | 16 | NoInlineAttr::CreateImplicit(S.getASTContext(), FD->getLocation())); |
441 | 16 | } |
442 | | |
443 | | /// Build calls to await_ready, await_suspend, and await_resume for a co_await |
444 | | /// expression. |
445 | | /// The generated AST tries to clean up temporary objects as early as |
446 | | /// possible so that they don't live across suspension points if possible. |
447 | | /// Having temporary objects living across suspension points unnecessarily can |
448 | | /// lead to large frame size, and also lead to memory corruptions if the |
449 | | /// coroutine frame is destroyed after coming back from suspension. This is done |
450 | | /// by wrapping both the await_ready call and the await_suspend call with |
451 | | /// ExprWithCleanups. In the end of this function, we also need to explicitly |
452 | | /// set cleanup state so that the CoawaitExpr is also wrapped with an |
453 | | /// ExprWithCleanups to clean up the awaiter associated with the co_await |
454 | | /// expression. |
455 | | static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise, |
456 | 1.25k | SourceLocation Loc, Expr *E) { |
457 | 1.25k | OpaqueValueExpr *Operand = new (S.Context) |
458 | 1.25k | OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E); |
459 | | |
460 | | // Assume valid until we see otherwise. |
461 | | // Further operations are responsible for setting IsInalid to true. |
462 | 1.25k | ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/false}; |
463 | | |
464 | 1.25k | using ACT = ReadySuspendResumeResult::AwaitCallType; |
465 | | |
466 | 1.25k | auto BuildSubExpr = [&](ACT CallType, StringRef Func, |
467 | 3.71k | MultiExprArg Arg) -> Expr * { |
468 | 3.71k | ExprResult Result = buildMemberCall(S, Operand, Loc, Func, Arg); |
469 | 3.71k | if (Result.isInvalid()) { |
470 | 27 | Calls.IsInvalid = true; |
471 | 27 | return nullptr; |
472 | 27 | } |
473 | 3.68k | Calls.Results[CallType] = Result.get(); |
474 | 3.68k | return Result.get(); |
475 | 3.71k | }; |
476 | | |
477 | 1.25k | CallExpr *AwaitReady = cast_or_null<CallExpr>( |
478 | 1.25k | BuildSubExpr(ACT::ACT_Ready, "await_ready", std::nullopt)); |
479 | 1.25k | if (!AwaitReady) |
480 | 23 | return Calls; |
481 | 1.23k | if (!AwaitReady->getType()->isDependentType()) { |
482 | | // [expr.await]p3 [...] |
483 | | // — await-ready is the expression e.await_ready(), contextually converted |
484 | | // to bool. |
485 | 1.23k | ExprResult Conv = S.PerformContextuallyConvertToBool(AwaitReady); |
486 | 1.23k | if (Conv.isInvalid()) { |
487 | 2 | S.Diag(AwaitReady->getDirectCallee()->getBeginLoc(), |
488 | 2 | diag::note_await_ready_no_bool_conversion); |
489 | 2 | S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required) |
490 | 2 | << AwaitReady->getDirectCallee() << E->getSourceRange(); |
491 | 2 | Calls.IsInvalid = true; |
492 | 2 | } else |
493 | 1.23k | Calls.Results[ACT::ACT_Ready] = S.MaybeCreateExprWithCleanups(Conv.get()); |
494 | 1.23k | } |
495 | | |
496 | 1.23k | ExprResult CoroHandleRes = |
497 | 1.23k | buildCoroutineHandle(S, CoroPromise->getType(), Loc); |
498 | 1.23k | if (CoroHandleRes.isInvalid()) { |
499 | 4 | Calls.IsInvalid = true; |
500 | 4 | return Calls; |
501 | 4 | } |
502 | 1.22k | Expr *CoroHandle = CoroHandleRes.get(); |
503 | 1.22k | CallExpr *AwaitSuspend = cast_or_null<CallExpr>( |
504 | 1.22k | BuildSubExpr(ACT::ACT_Suspend, "await_suspend", CoroHandle)); |
505 | 1.22k | if (!AwaitSuspend) |
506 | 2 | return Calls; |
507 | 1.22k | if (!AwaitSuspend->getType()->isDependentType()) { |
508 | | // [expr.await]p3 [...] |
509 | | // - await-suspend is the expression e.await_suspend(h), which shall be |
510 | | // a prvalue of type void, bool, or std::coroutine_handle<Z> for some |
511 | | // type Z. |
512 | 1.22k | QualType RetType = AwaitSuspend->getCallReturnType(S.Context); |
513 | | |
514 | | // We need to mark await_suspend as noinline temporarily. See the comment |
515 | | // of tryMarkAwaitSuspendNoInline for details. |
516 | 1.22k | tryMarkAwaitSuspendNoInline(S, Operand, AwaitSuspend); |
517 | | |
518 | | // Support for coroutine_handle returning await_suspend. |
519 | 1.22k | if (Expr *TailCallSuspend = |
520 | 1.22k | maybeTailCall(S, RetType, AwaitSuspend, Loc)) |
521 | | // Note that we don't wrap the expression with ExprWithCleanups here |
522 | | // because that might interfere with tailcall contract (e.g. inserting |
523 | | // clean up instructions in-between tailcall and return). Instead |
524 | | // ExprWithCleanups is wrapped within maybeTailCall() prior to the resume |
525 | | // call. |
526 | 36 | Calls.Results[ACT::ACT_Suspend] = TailCallSuspend; |
527 | 1.19k | else { |
528 | | // non-class prvalues always have cv-unqualified types |
529 | 1.19k | if (RetType->isReferenceType() || |
530 | 1.19k | (1.18k !RetType->isBooleanType()1.18k && !RetType->isVoidType()1.18k )) { |
531 | 6 | S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(), |
532 | 6 | diag::err_await_suspend_invalid_return_type) |
533 | 6 | << RetType; |
534 | 6 | S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required) |
535 | 6 | << AwaitSuspend->getDirectCallee(); |
536 | 6 | Calls.IsInvalid = true; |
537 | 6 | } else |
538 | 1.18k | Calls.Results[ACT::ACT_Suspend] = |
539 | 1.18k | S.MaybeCreateExprWithCleanups(AwaitSuspend); |
540 | 1.19k | } |
541 | 1.22k | } |
542 | | |
543 | 1.22k | BuildSubExpr(ACT::ACT_Resume, "await_resume", std::nullopt); |
544 | | |
545 | | // Make sure the awaiter object gets a chance to be cleaned up. |
546 | 1.22k | S.Cleanup.setExprNeedsCleanups(true); |
547 | | |
548 | 1.22k | return Calls; |
549 | 1.22k | } |
550 | | |
551 | | static ExprResult buildPromiseCall(Sema &S, VarDecl *Promise, |
552 | | SourceLocation Loc, StringRef Name, |
553 | 2.34k | MultiExprArg Args) { |
554 | | |
555 | | // Form a reference to the promise. |
556 | 2.34k | ExprResult PromiseRef = S.BuildDeclRefExpr( |
557 | 2.34k | Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc); |
558 | 2.34k | if (PromiseRef.isInvalid()) |
559 | 0 | return ExprError(); |
560 | | |
561 | 2.34k | return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args); |
562 | 2.34k | } |
563 | | |
564 | 609 | VarDecl *Sema::buildCoroutinePromise(SourceLocation Loc) { |
565 | 609 | assert(isa<FunctionDecl>(CurContext) && "not in a function scope"); |
566 | 609 | auto *FD = cast<FunctionDecl>(CurContext); |
567 | 609 | bool IsThisDependentType = [&] { |
568 | 609 | if (const auto *MD = dyn_cast_if_present<CXXMethodDecl>(FD)) |
569 | 173 | return MD->isImplicitObjectMemberFunction() && |
570 | 173 | MD->getThisType()->isDependentType()144 ; |
571 | 436 | return false; |
572 | 609 | }(); |
573 | | |
574 | 609 | QualType T = FD->getType()->isDependentType() || IsThisDependentType531 |
575 | 609 | ? Context.DependentTy103 |
576 | 609 | : lookupPromiseType(*this, FD, Loc)506 ; |
577 | 609 | if (T.isNull()) |
578 | 26 | return nullptr; |
579 | | |
580 | 583 | auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(), |
581 | 583 | &PP.getIdentifierTable().get("__promise"), T, |
582 | 583 | Context.getTrivialTypeSourceInfo(T, Loc), SC_None); |
583 | 583 | VD->setImplicit(); |
584 | 583 | CheckVariableDeclarationType(VD); |
585 | 583 | if (VD->isInvalidDecl()) |
586 | 0 | return nullptr; |
587 | | |
588 | 583 | auto *ScopeInfo = getCurFunction(); |
589 | | |
590 | | // Build a list of arguments, based on the coroutine function's arguments, |
591 | | // that if present will be passed to the promise type's constructor. |
592 | 583 | llvm::SmallVector<Expr *, 4> CtorArgExprs; |
593 | | |
594 | | // Add implicit object parameter. |
595 | 583 | if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) { |
596 | 166 | if (MD->isImplicitObjectMemberFunction() && !isLambdaCallOperator(MD)140 ) { |
597 | 109 | ExprResult ThisExpr = ActOnCXXThis(Loc); |
598 | 109 | if (ThisExpr.isInvalid()) |
599 | 0 | return nullptr; |
600 | 109 | ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get()); |
601 | 109 | if (ThisExpr.isInvalid()) |
602 | 0 | return nullptr; |
603 | 109 | CtorArgExprs.push_back(ThisExpr.get()); |
604 | 109 | } |
605 | 166 | } |
606 | | |
607 | | // Add the coroutine function's parameters. |
608 | 583 | auto &Moves = ScopeInfo->CoroutineParameterMoves; |
609 | 583 | for (auto *PD : FD->parameters()) { |
610 | 432 | if (PD->getType()->isDependentType()) |
611 | 84 | continue; |
612 | | |
613 | 348 | auto RefExpr = ExprEmpty(); |
614 | 348 | auto Move = Moves.find(PD); |
615 | 348 | assert(Move != Moves.end() && |
616 | 348 | "Coroutine function parameter not inserted into move map"); |
617 | | // If a reference to the function parameter exists in the coroutine |
618 | | // frame, use that reference. |
619 | 348 | auto *MoveDecl = |
620 | 348 | cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl()); |
621 | 348 | RefExpr = |
622 | 348 | BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(), |
623 | 348 | ExprValueKind::VK_LValue, FD->getLocation()); |
624 | 348 | if (RefExpr.isInvalid()) |
625 | 0 | return nullptr; |
626 | 348 | CtorArgExprs.push_back(RefExpr.get()); |
627 | 348 | } |
628 | | |
629 | | // If we have a non-zero number of constructor arguments, try to use them. |
630 | | // Otherwise, fall back to the promise type's default constructor. |
631 | 583 | if (!CtorArgExprs.empty()) { |
632 | | // Create an initialization sequence for the promise type using the |
633 | | // constructor arguments, wrapped in a parenthesized list expression. |
634 | 291 | Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(), |
635 | 291 | CtorArgExprs, FD->getLocation()); |
636 | 291 | InitializedEntity Entity = InitializedEntity::InitializeVariable(VD); |
637 | 291 | InitializationKind Kind = InitializationKind::CreateForInit( |
638 | 291 | VD->getLocation(), /*DirectInit=*/true, PLE); |
639 | 291 | InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs, |
640 | 291 | /*TopLevelOfInitList=*/false, |
641 | 291 | /*TreatUnavailableAsInvalid=*/false); |
642 | | |
643 | | // [dcl.fct.def.coroutine]5.7 |
644 | | // promise-constructor-arguments is determined as follows: overload |
645 | | // resolution is performed on a promise constructor call created by |
646 | | // assembling an argument list q_1 ... q_n . If a viable constructor is |
647 | | // found ([over.match.viable]), then promise-constructor-arguments is ( q_1 |
648 | | // , ..., q_n ), otherwise promise-constructor-arguments is empty. |
649 | 291 | if (InitSeq) { |
650 | 56 | ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs); |
651 | 56 | if (Result.isInvalid()) { |
652 | 0 | VD->setInvalidDecl(); |
653 | 56 | } else if (Result.get()) { |
654 | 56 | VD->setInit(MaybeCreateExprWithCleanups(Result.get())); |
655 | 56 | VD->setInitStyle(VarDecl::CallInit); |
656 | 56 | CheckCompleteVariableDeclaration(VD); |
657 | 56 | } |
658 | 56 | } else |
659 | 235 | ActOnUninitializedDecl(VD); |
660 | 291 | } else |
661 | 292 | ActOnUninitializedDecl(VD); |
662 | | |
663 | 583 | FD->addDecl(VD); |
664 | 583 | return VD; |
665 | 583 | } |
666 | | |
667 | | /// Check that this is a context in which a coroutine suspension can appear. |
668 | | static FunctionScopeInfo *checkCoroutineContext(Sema &S, SourceLocation Loc, |
669 | | StringRef Keyword, |
670 | 2.94k | bool IsImplicit = false) { |
671 | 2.94k | if (!isValidCoroutineContext(S, Loc, Keyword)) |
672 | 17 | return nullptr; |
673 | | |
674 | 2.93k | assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope"); |
675 | | |
676 | 2.93k | auto *ScopeInfo = S.getCurFunction(); |
677 | 2.93k | assert(ScopeInfo && "missing function scope for function"); |
678 | | |
679 | 2.93k | if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit822 ) |
680 | 608 | ScopeInfo->setFirstCoroutineStmt(Loc, Keyword); |
681 | | |
682 | 2.93k | if (ScopeInfo->CoroutinePromise) |
683 | 2.42k | return ScopeInfo; |
684 | | |
685 | 504 | if (!S.buildCoroutineParameterMoves(Loc)) |
686 | 2 | return nullptr; |
687 | | |
688 | 502 | ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc); |
689 | 502 | if (!ScopeInfo->CoroutinePromise) |
690 | 26 | return nullptr; |
691 | | |
692 | 476 | return ScopeInfo; |
693 | 502 | } |
694 | | |
695 | | /// Recursively check \p E and all its children to see if any call target |
696 | | /// (including constructor call) is declared noexcept. Also any value returned |
697 | | /// from the call has a noexcept destructor. |
698 | | static void checkNoThrow(Sema &S, const Stmt *E, |
699 | 4.64k | llvm::SmallPtrSetImpl<const Decl *> &ThrowingDecls) { |
700 | 4.64k | auto checkDeclNoexcept = [&](const Decl *D, bool IsDtor = false) { |
701 | | // In the case of dtor, the call to dtor is implicit and hence we should |
702 | | // pass nullptr to canCalleeThrow. |
703 | 2.32k | if (Sema::canCalleeThrow(S, IsDtor ? nullptr14 : cast<Expr>(E)2.31k , D)) { |
704 | 37 | if (const auto *FD = dyn_cast<FunctionDecl>(D)) { |
705 | | // co_await promise.final_suspend() could end up calling |
706 | | // __builtin_coro_resume for symmetric transfer if await_suspend() |
707 | | // returns a handle. In that case, even __builtin_coro_resume is not |
708 | | // declared as noexcept and may throw, it does not throw _into_ the |
709 | | // coroutine that just suspended, but rather throws back out from |
710 | | // whoever called coroutine_handle::resume(), hence we claim that |
711 | | // logically it does not throw. |
712 | 37 | if (FD->getBuiltinID() == Builtin::BI__builtin_coro_resume) |
713 | 21 | return; |
714 | 37 | } |
715 | 16 | if (ThrowingDecls.empty()) { |
716 | | // [dcl.fct.def.coroutine]p15 |
717 | | // The expression co_await promise.final_suspend() shall not be |
718 | | // potentially-throwing ([except.spec]). |
719 | | // |
720 | | // First time seeing an error, emit the error message. |
721 | 3 | S.Diag(cast<FunctionDecl>(S.CurContext)->getLocation(), |
722 | 3 | diag::err_coroutine_promise_final_suspend_requires_nothrow); |
723 | 3 | } |
724 | 16 | ThrowingDecls.insert(D); |
725 | 16 | } |
726 | 2.32k | }; |
727 | | |
728 | 4.64k | if (auto *CE = dyn_cast<CXXConstructExpr>(E)) { |
729 | 0 | CXXConstructorDecl *Ctor = CE->getConstructor(); |
730 | 0 | checkDeclNoexcept(Ctor); |
731 | | // Check the corresponding destructor of the constructor. |
732 | 0 | checkDeclNoexcept(Ctor->getParent()->getDestructor(), /*IsDtor=*/true); |
733 | 4.64k | } else if (auto *CE = dyn_cast<CallExpr>(E)) { |
734 | 2.51k | if (CE->isTypeDependent()) |
735 | 206 | return; |
736 | | |
737 | 2.31k | checkDeclNoexcept(CE->getCalleeDecl()); |
738 | 2.31k | QualType ReturnType = CE->getCallReturnType(S.getASTContext()); |
739 | | // Check the destructor of the call return type, if any. |
740 | 2.31k | if (ReturnType.isDestructedType() == |
741 | 2.31k | QualType::DestructionKind::DK_cxx_destructor) { |
742 | 14 | const auto *T = |
743 | 14 | cast<RecordType>(ReturnType.getCanonicalType().getTypePtr()); |
744 | 14 | checkDeclNoexcept(cast<CXXRecordDecl>(T->getDecl())->getDestructor(), |
745 | 14 | /*IsDtor=*/true); |
746 | 14 | } |
747 | 2.31k | } else |
748 | 4.38k | for (const auto *Child : E->children())2.12k { |
749 | 4.38k | if (!Child) |
750 | 309 | continue; |
751 | 4.07k | checkNoThrow(S, Child, ThrowingDecls); |
752 | 4.07k | } |
753 | 4.64k | } |
754 | | |
755 | 565 | bool Sema::checkFinalSuspendNoThrow(const Stmt *FinalSuspend) { |
756 | 565 | llvm::SmallPtrSet<const Decl *, 4> ThrowingDecls; |
757 | | // We first collect all declarations that should not throw but not declared |
758 | | // with noexcept. We then sort them based on the location before printing. |
759 | | // This is to avoid emitting the same note multiple times on the same |
760 | | // declaration, and also provide a deterministic order for the messages. |
761 | 565 | checkNoThrow(*this, FinalSuspend, ThrowingDecls); |
762 | 565 | auto SortedDecls = llvm::SmallVector<const Decl *, 4>{ThrowingDecls.begin(), |
763 | 565 | ThrowingDecls.end()}; |
764 | 565 | sort(SortedDecls, [](const Decl *A, const Decl *B) { |
765 | 14 | return A->getEndLoc() < B->getEndLoc(); |
766 | 14 | }); |
767 | 565 | for (const auto *D : SortedDecls) { |
768 | 11 | Diag(D->getEndLoc(), diag::note_coroutine_function_declare_noexcept); |
769 | 11 | } |
770 | 565 | return ThrowingDecls.empty(); |
771 | 565 | } |
772 | | |
773 | | bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc, |
774 | 630 | StringRef Keyword) { |
775 | 630 | if (!checkCoroutineContext(*this, KWLoc, Keyword)) |
776 | 45 | return false; |
777 | 585 | auto *ScopeInfo = getCurFunction(); |
778 | 585 | assert(ScopeInfo->CoroutinePromise); |
779 | | |
780 | | // If we have existing coroutine statements then we have already built |
781 | | // the initial and final suspend points. |
782 | 585 | if (!ScopeInfo->NeedsCoroutineSuspends) |
783 | 109 | return true; |
784 | | |
785 | 476 | ScopeInfo->setNeedsCoroutineSuspends(false); |
786 | | |
787 | 476 | auto *Fn = cast<FunctionDecl>(CurContext); |
788 | 476 | SourceLocation Loc = Fn->getLocation(); |
789 | | // Build the initial suspend point |
790 | 938 | auto buildSuspends = [&](StringRef Name) mutable -> StmtResult { |
791 | 938 | ExprResult Operand = buildPromiseCall(*this, ScopeInfo->CoroutinePromise, |
792 | 938 | Loc, Name, std::nullopt); |
793 | 938 | if (Operand.isInvalid()) |
794 | 6 | return StmtError(); |
795 | 932 | ExprResult Suspend = |
796 | 932 | buildOperatorCoawaitCall(*this, SC, Loc, Operand.get()); |
797 | 932 | if (Suspend.isInvalid()) |
798 | 0 | return StmtError(); |
799 | 932 | Suspend = BuildResolvedCoawaitExpr(Loc, Operand.get(), Suspend.get(), |
800 | 932 | /*IsImplicit*/ true); |
801 | 932 | Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false); |
802 | 932 | if (Suspend.isInvalid()) { |
803 | 12 | Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required) |
804 | 12 | << ((Name == "initial_suspend") ? 010 : 12 ); |
805 | 12 | Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword; |
806 | 12 | return StmtError(); |
807 | 12 | } |
808 | 920 | return cast<Stmt>(Suspend.get()); |
809 | 932 | }; |
810 | | |
811 | 476 | StmtResult InitSuspend = buildSuspends("initial_suspend"); |
812 | 476 | if (InitSuspend.isInvalid()) |
813 | 14 | return true; |
814 | | |
815 | 462 | StmtResult FinalSuspend = buildSuspends("final_suspend"); |
816 | 462 | if (FinalSuspend.isInvalid() || !checkFinalSuspendNoThrow(FinalSuspend.get())458 ) |
817 | 6 | return true; |
818 | | |
819 | 456 | ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get()); |
820 | | |
821 | 456 | return true; |
822 | 462 | } |
823 | | |
824 | | // Recursively walks up the scope hierarchy until either a 'catch' or a function |
825 | | // scope is found, whichever comes first. |
826 | 373 | static bool isWithinCatchScope(Scope *S) { |
827 | | // 'co_await' and 'co_yield' keywords are disallowed within catch blocks, but |
828 | | // lambdas that use 'co_await' are allowed. The loop below ends when a |
829 | | // function scope is found in order to ensure the following behavior: |
830 | | // |
831 | | // void foo() { // <- function scope |
832 | | // try { // |
833 | | // co_await x; // <- 'co_await' is OK within a function scope |
834 | | // } catch { // <- catch scope |
835 | | // co_await x; // <- 'co_await' is not OK within a catch scope |
836 | | // []() { // <- function scope |
837 | | // co_await x; // <- 'co_await' is OK within a function scope |
838 | | // }(); |
839 | | // } |
840 | | // } |
841 | 452 | while (S && !S->isFunctionScope()444 ) { |
842 | 85 | if (S->isCatchScope()) |
843 | 6 | return true; |
844 | 79 | S = S->getParent(); |
845 | 79 | } |
846 | 367 | return false; |
847 | 373 | } |
848 | | |
849 | | // [expr.await]p2, emphasis added: "An await-expression shall appear only in |
850 | | // a *potentially evaluated* expression within the compound-statement of a |
851 | | // function-body *outside of a handler* [...] A context within a function |
852 | | // where an await-expression can appear is called a suspension context of the |
853 | | // function." |
854 | | static bool checkSuspensionContext(Sema &S, SourceLocation Loc, |
855 | 387 | StringRef Keyword) { |
856 | | // First emphasis of [expr.await]p2: must be a potentially evaluated context. |
857 | | // That is, 'co_await' and 'co_yield' cannot appear in subexpressions of |
858 | | // \c sizeof. |
859 | 387 | if (S.isUnevaluatedContext()) { |
860 | 14 | S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword; |
861 | 14 | return false; |
862 | 14 | } |
863 | | |
864 | | // Second emphasis of [expr.await]p2: must be outside of an exception handler. |
865 | 373 | if (isWithinCatchScope(S.getCurScope())) { |
866 | 6 | S.Diag(Loc, diag::err_coroutine_within_handler) << Keyword; |
867 | 6 | return false; |
868 | 6 | } |
869 | | |
870 | 367 | return true; |
871 | 373 | } |
872 | | |
873 | 253 | ExprResult Sema::ActOnCoawaitExpr(Scope *S, SourceLocation Loc, Expr *E) { |
874 | 253 | if (!checkSuspensionContext(*this, Loc, "co_await")) |
875 | 11 | return ExprError(); |
876 | | |
877 | 242 | if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) { |
878 | 26 | CorrectDelayedTyposInExpr(E); |
879 | 26 | return ExprError(); |
880 | 26 | } |
881 | | |
882 | 216 | if (E->hasPlaceholderType()) { |
883 | 4 | ExprResult R = CheckPlaceholderExpr(E); |
884 | 4 | if (R.isInvalid()) return ExprError()0 ; |
885 | 4 | E = R.get(); |
886 | 4 | } |
887 | 216 | ExprResult Lookup = BuildOperatorCoawaitLookupExpr(S, Loc); |
888 | 216 | if (Lookup.isInvalid()) |
889 | 0 | return ExprError(); |
890 | 216 | return BuildUnresolvedCoawaitExpr(Loc, E, |
891 | 216 | cast<UnresolvedLookupExpr>(Lookup.get())); |
892 | 216 | } |
893 | | |
894 | 1.48k | ExprResult Sema::BuildOperatorCoawaitLookupExpr(Scope *S, SourceLocation Loc) { |
895 | 1.48k | DeclarationName OpName = |
896 | 1.48k | Context.DeclarationNames.getCXXOperatorName(OO_Coawait); |
897 | 1.48k | LookupResult Operators(*this, OpName, SourceLocation(), |
898 | 1.48k | Sema::LookupOperatorName); |
899 | 1.48k | LookupName(Operators, S); |
900 | | |
901 | 1.48k | assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); |
902 | 1.48k | const auto &Functions = Operators.asUnresolvedSet(); |
903 | 1.48k | bool IsOverloaded = |
904 | 1.48k | Functions.size() > 1 || |
905 | 1.48k | (1.39k Functions.size() == 11.39k && isa<FunctionTemplateDecl>(*Functions.begin())69 ); |
906 | 1.48k | Expr *CoawaitOp = UnresolvedLookupExpr::Create( |
907 | 1.48k | Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(), |
908 | 1.48k | DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded, |
909 | 1.48k | Functions.begin(), Functions.end()); |
910 | 1.48k | assert(CoawaitOp); |
911 | 1.48k | return CoawaitOp; |
912 | 1.48k | } |
913 | | |
914 | | // Attempts to resolve and build a CoawaitExpr from "raw" inputs, bailing out to |
915 | | // DependentCoawaitExpr if needed. |
916 | | ExprResult Sema::BuildUnresolvedCoawaitExpr(SourceLocation Loc, Expr *Operand, |
917 | 265 | UnresolvedLookupExpr *Lookup) { |
918 | 265 | auto *FSI = checkCoroutineContext(*this, Loc, "co_await"); |
919 | 265 | if (!FSI) |
920 | 0 | return ExprError(); |
921 | | |
922 | 265 | if (Operand->hasPlaceholderType()) { |
923 | 0 | ExprResult R = CheckPlaceholderExpr(Operand); |
924 | 0 | if (R.isInvalid()) |
925 | 0 | return ExprError(); |
926 | 0 | Operand = R.get(); |
927 | 0 | } |
928 | | |
929 | 265 | auto *Promise = FSI->CoroutinePromise; |
930 | 265 | if (Promise->getType()->isDependentType()) { |
931 | 49 | Expr *Res = new (Context) |
932 | 49 | DependentCoawaitExpr(Loc, Context.DependentTy, Operand, Lookup); |
933 | 49 | return Res; |
934 | 49 | } |
935 | | |
936 | 216 | auto *RD = Promise->getType()->getAsCXXRecordDecl(); |
937 | 216 | auto *Transformed = Operand; |
938 | 216 | if (lookupMember(*this, "await_transform", RD, Loc)) { |
939 | 53 | ExprResult R = |
940 | 53 | buildPromiseCall(*this, Promise, Loc, "await_transform", Operand); |
941 | 53 | if (R.isInvalid()) { |
942 | 5 | Diag(Loc, |
943 | 5 | diag::note_coroutine_promise_implicit_await_transform_required_here) |
944 | 5 | << Operand->getSourceRange(); |
945 | 5 | return ExprError(); |
946 | 5 | } |
947 | 48 | Transformed = R.get(); |
948 | 48 | } |
949 | 211 | ExprResult Awaiter = BuildOperatorCoawaitCall(Loc, Transformed, Lookup); |
950 | 211 | if (Awaiter.isInvalid()) |
951 | 6 | return ExprError(); |
952 | | |
953 | 205 | return BuildResolvedCoawaitExpr(Loc, Operand, Awaiter.get()); |
954 | 211 | } |
955 | | |
956 | | ExprResult Sema::BuildResolvedCoawaitExpr(SourceLocation Loc, Expr *Operand, |
957 | 1.35k | Expr *Awaiter, bool IsImplicit) { |
958 | 1.35k | auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit); |
959 | 1.35k | if (!Coroutine) |
960 | 0 | return ExprError(); |
961 | | |
962 | 1.35k | if (Awaiter->hasPlaceholderType()) { |
963 | 0 | ExprResult R = CheckPlaceholderExpr(Awaiter); |
964 | 0 | if (R.isInvalid()) return ExprError(); |
965 | 0 | Awaiter = R.get(); |
966 | 0 | } |
967 | | |
968 | 1.35k | if (Awaiter->getType()->isDependentType()) { |
969 | 215 | Expr *Res = new (Context) |
970 | 215 | CoawaitExpr(Loc, Context.DependentTy, Operand, Awaiter, IsImplicit); |
971 | 215 | return Res; |
972 | 215 | } |
973 | | |
974 | | // If the expression is a temporary, materialize it as an lvalue so that we |
975 | | // can use it multiple times. |
976 | 1.14k | if (Awaiter->isPRValue()) |
977 | 1.05k | Awaiter = CreateMaterializeTemporaryExpr(Awaiter->getType(), Awaiter, true); |
978 | | |
979 | | // The location of the `co_await` token cannot be used when constructing |
980 | | // the member call expressions since it's before the location of `Expr`, which |
981 | | // is used as the start of the member call expression. |
982 | 1.14k | SourceLocation CallLoc = Awaiter->getExprLoc(); |
983 | | |
984 | | // Build the await_ready, await_suspend, await_resume calls. |
985 | 1.14k | ReadySuspendResumeResult RSS = |
986 | 1.14k | buildCoawaitCalls(*this, Coroutine->CoroutinePromise, CallLoc, Awaiter); |
987 | 1.14k | if (RSS.IsInvalid) |
988 | 37 | return ExprError(); |
989 | | |
990 | 1.10k | Expr *Res = new (Context) |
991 | 1.10k | CoawaitExpr(Loc, Operand, Awaiter, RSS.Results[0], RSS.Results[1], |
992 | 1.10k | RSS.Results[2], RSS.OpaqueValue, IsImplicit); |
993 | | |
994 | 1.10k | return Res; |
995 | 1.14k | } |
996 | | |
997 | 134 | ExprResult Sema::ActOnCoyieldExpr(Scope *S, SourceLocation Loc, Expr *E) { |
998 | 134 | if (!checkSuspensionContext(*this, Loc, "co_yield")) |
999 | 9 | return ExprError(); |
1000 | | |
1001 | 125 | if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) { |
1002 | 6 | CorrectDelayedTyposInExpr(E); |
1003 | 6 | return ExprError(); |
1004 | 6 | } |
1005 | | |
1006 | | // Build yield_value call. |
1007 | 119 | ExprResult Awaitable = buildPromiseCall( |
1008 | 119 | *this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E); |
1009 | 119 | if (Awaitable.isInvalid()) |
1010 | 6 | return ExprError(); |
1011 | | |
1012 | | // Build 'operator co_await' call. |
1013 | 113 | Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get()); |
1014 | 113 | if (Awaitable.isInvalid()) |
1015 | 0 | return ExprError(); |
1016 | | |
1017 | 113 | return BuildCoyieldExpr(Loc, Awaitable.get()); |
1018 | 113 | } |
1019 | 160 | ExprResult Sema::BuildCoyieldExpr(SourceLocation Loc, Expr *E) { |
1020 | 160 | auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield"); |
1021 | 160 | if (!Coroutine) |
1022 | 0 | return ExprError(); |
1023 | | |
1024 | 160 | if (E->hasPlaceholderType()) { |
1025 | 0 | ExprResult R = CheckPlaceholderExpr(E); |
1026 | 0 | if (R.isInvalid()) return ExprError(); |
1027 | 0 | E = R.get(); |
1028 | 0 | } |
1029 | | |
1030 | 160 | Expr *Operand = E; |
1031 | | |
1032 | 160 | if (E->getType()->isDependentType()) { |
1033 | 48 | Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, Operand, E); |
1034 | 48 | return Res; |
1035 | 48 | } |
1036 | | |
1037 | | // If the expression is a temporary, materialize it as an lvalue so that we |
1038 | | // can use it multiple times. |
1039 | 112 | if (E->isPRValue()) |
1040 | 112 | E = CreateMaterializeTemporaryExpr(E->getType(), E, true); |
1041 | | |
1042 | | // Build the await_ready, await_suspend, await_resume calls. |
1043 | 112 | ReadySuspendResumeResult RSS = buildCoawaitCalls( |
1044 | 112 | *this, Coroutine->CoroutinePromise, Loc, E); |
1045 | 112 | if (RSS.IsInvalid) |
1046 | 2 | return ExprError(); |
1047 | | |
1048 | 110 | Expr *Res = |
1049 | 110 | new (Context) CoyieldExpr(Loc, Operand, E, RSS.Results[0], RSS.Results[1], |
1050 | 110 | RSS.Results[2], RSS.OpaqueValue); |
1051 | | |
1052 | 110 | return Res; |
1053 | 112 | } |
1054 | | |
1055 | 255 | StmtResult Sema::ActOnCoreturnStmt(Scope *S, SourceLocation Loc, Expr *E) { |
1056 | 255 | if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) { |
1057 | 12 | CorrectDelayedTyposInExpr(E); |
1058 | 12 | return StmtError(); |
1059 | 12 | } |
1060 | 243 | return BuildCoreturnStmt(Loc, E); |
1061 | 255 | } |
1062 | | |
1063 | | StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E, |
1064 | 533 | bool IsImplicit) { |
1065 | 533 | auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit); |
1066 | 533 | if (!FSI) |
1067 | 0 | return StmtError(); |
1068 | | |
1069 | 533 | if (E && E->hasPlaceholderType()115 && |
1070 | 533 | !E->hasPlaceholderType(BuiltinType::Overload)4 ) { |
1071 | 0 | ExprResult R = CheckPlaceholderExpr(E); |
1072 | 0 | if (R.isInvalid()) return StmtError(); |
1073 | 0 | E = R.get(); |
1074 | 0 | } |
1075 | | |
1076 | 533 | VarDecl *Promise = FSI->CoroutinePromise; |
1077 | 533 | ExprResult PC; |
1078 | 533 | if (E && (115 isa<InitListExpr>(E)115 || !E->getType()->isVoidType()109 )) { |
1079 | 114 | getNamedReturnInfo(E, SimplerImplicitMoveMode::ForceOn); |
1080 | 114 | PC = buildPromiseCall(*this, Promise, Loc, "return_value", E); |
1081 | 419 | } else { |
1082 | 419 | E = MakeFullDiscardedValueExpr(E).get(); |
1083 | 419 | PC = buildPromiseCall(*this, Promise, Loc, "return_void", std::nullopt); |
1084 | 419 | } |
1085 | 533 | if (PC.isInvalid()) |
1086 | 16 | return StmtError(); |
1087 | | |
1088 | 517 | Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get(); |
1089 | | |
1090 | 517 | Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit); |
1091 | 517 | return Res; |
1092 | 533 | } |
1093 | | |
1094 | | /// Look up the std::nothrow object. |
1095 | 19 | static Expr *buildStdNoThrowDeclRef(Sema &S, SourceLocation Loc) { |
1096 | 19 | NamespaceDecl *Std = S.getStdNamespace(); |
1097 | 19 | assert(Std && "Should already be diagnosed"); |
1098 | | |
1099 | 19 | LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc, |
1100 | 19 | Sema::LookupOrdinaryName); |
1101 | 19 | if (!S.LookupQualifiedName(Result, Std)) { |
1102 | | // <coroutine> is not requred to include <new>, so we couldn't omit |
1103 | | // the check here. |
1104 | 0 | S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found); |
1105 | 0 | return nullptr; |
1106 | 0 | } |
1107 | | |
1108 | 19 | auto *VD = Result.getAsSingle<VarDecl>(); |
1109 | 19 | if (!VD) { |
1110 | 0 | Result.suppressDiagnostics(); |
1111 | | // We found something weird. Complain about the first thing we found. |
1112 | 0 | NamedDecl *Found = *Result.begin(); |
1113 | 0 | S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow); |
1114 | 0 | return nullptr; |
1115 | 0 | } |
1116 | | |
1117 | 19 | ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc); |
1118 | 19 | if (DR.isInvalid()) |
1119 | 0 | return nullptr; |
1120 | | |
1121 | 19 | return DR.get(); |
1122 | 19 | } |
1123 | | |
1124 | | static TypeSourceInfo *getTypeSourceInfoForStdAlignValT(Sema &S, |
1125 | 25 | SourceLocation Loc) { |
1126 | 25 | EnumDecl *StdAlignValT = S.getStdAlignValT(); |
1127 | 25 | QualType StdAlignValDecl = S.Context.getTypeDeclType(StdAlignValT); |
1128 | 25 | return S.Context.getTrivialTypeSourceInfo(StdAlignValDecl); |
1129 | 25 | } |
1130 | | |
1131 | | // Find an appropriate delete for the promise. |
1132 | | static bool findDeleteForPromise(Sema &S, SourceLocation Loc, QualType PromiseType, |
1133 | 402 | FunctionDecl *&OperatorDelete) { |
1134 | 402 | DeclarationName DeleteName = |
1135 | 402 | S.Context.DeclarationNames.getCXXOperatorName(OO_Delete); |
1136 | | |
1137 | 402 | auto *PointeeRD = PromiseType->getAsCXXRecordDecl(); |
1138 | 402 | assert(PointeeRD && "PromiseType must be a CxxRecordDecl type"); |
1139 | | |
1140 | 402 | const bool Overaligned = S.getLangOpts().CoroAlignedAllocation; |
1141 | | |
1142 | | // [dcl.fct.def.coroutine]p12 |
1143 | | // The deallocation function's name is looked up by searching for it in the |
1144 | | // scope of the promise type. If nothing is found, a search is performed in |
1145 | | // the global scope. |
1146 | 402 | if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete, |
1147 | 402 | /*Diagnose*/ true, /*WantSize*/ true, |
1148 | 402 | /*WantAligned*/ Overaligned)) |
1149 | 2 | return false; |
1150 | | |
1151 | | // [dcl.fct.def.coroutine]p12 |
1152 | | // If both a usual deallocation function with only a pointer parameter and a |
1153 | | // usual deallocation function with both a pointer parameter and a size |
1154 | | // parameter are found, then the selected deallocation function shall be the |
1155 | | // one with two parameters. Otherwise, the selected deallocation function |
1156 | | // shall be the function with one parameter. |
1157 | 400 | if (!OperatorDelete) { |
1158 | | // Look for a global declaration. |
1159 | | // Coroutines can always provide their required size. |
1160 | 387 | const bool CanProvideSize = true; |
1161 | | // Sema::FindUsualDeallocationFunction will try to find the one with two |
1162 | | // parameters first. It will return the deallocation function with one |
1163 | | // parameter if failed. |
1164 | 387 | OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize, |
1165 | 387 | Overaligned, DeleteName); |
1166 | | |
1167 | 387 | if (!OperatorDelete) |
1168 | 0 | return false; |
1169 | 387 | } |
1170 | | |
1171 | 400 | S.MarkFunctionReferenced(Loc, OperatorDelete); |
1172 | 400 | return true; |
1173 | 400 | } |
1174 | | |
1175 | | |
1176 | 608 | void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) { |
1177 | 608 | FunctionScopeInfo *Fn = getCurFunction(); |
1178 | 608 | assert(Fn && Fn->isCoroutine() && "not a coroutine"); |
1179 | 608 | if (!Body) { |
1180 | 19 | assert(FD->isInvalidDecl() && |
1181 | 19 | "a null body is only allowed for invalid declarations"); |
1182 | 19 | return; |
1183 | 19 | } |
1184 | | // We have a function that uses coroutine keywords, but we failed to build |
1185 | | // the promise type. |
1186 | 589 | if (!Fn->CoroutinePromise) |
1187 | 26 | return FD->setInvalidDecl(); |
1188 | | |
1189 | 563 | if (isa<CoroutineBodyStmt>(Body)) { |
1190 | | // Nothing todo. the body is already a transformed coroutine body statement. |
1191 | 87 | return; |
1192 | 87 | } |
1193 | | |
1194 | | // The always_inline attribute doesn't reliably apply to a coroutine, |
1195 | | // because the coroutine will be split into pieces and some pieces |
1196 | | // might be called indirectly, as in a virtual call. Even the ramp |
1197 | | // function cannot be inlined at -O0, due to pipeline ordering |
1198 | | // problems (see https://llvm.org/PR53413). Tell the user about it. |
1199 | 476 | if (FD->hasAttr<AlwaysInlineAttr>()) |
1200 | 6 | Diag(FD->getLocation(), diag::warn_always_inline_coroutine); |
1201 | | |
1202 | | // The design of coroutines means we cannot allow use of VLAs within one, so |
1203 | | // diagnose if we've seen a VLA in the body of this function. |
1204 | 476 | if (Fn->FirstVLALoc.isValid()) |
1205 | 2 | Diag(Fn->FirstVLALoc, diag::err_vla_in_coroutine_unsupported); |
1206 | | |
1207 | | // [stmt.return.coroutine]p1: |
1208 | | // A coroutine shall not enclose a return statement ([stmt.return]). |
1209 | 476 | if (Fn->FirstReturnLoc.isValid()) { |
1210 | 26 | assert(Fn->FirstCoroutineStmtLoc.isValid() && |
1211 | 26 | "first coroutine location not set"); |
1212 | 26 | Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine); |
1213 | 26 | Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here) |
1214 | 26 | << Fn->getFirstCoroutineStmtKeyword(); |
1215 | 26 | } |
1216 | | |
1217 | | // Coroutines will get splitted into pieces. The GNU address of label |
1218 | | // extension wouldn't be meaningful in coroutines. |
1219 | 476 | for (AddrLabelExpr *ALE : Fn->AddrLabels) |
1220 | 9 | Diag(ALE->getBeginLoc(), diag::err_coro_invalid_addr_of_label); |
1221 | | |
1222 | 476 | CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body); |
1223 | 476 | if (Builder.isInvalid() || !Builder.buildStatements()456 ) |
1224 | 50 | return FD->setInvalidDecl(); |
1225 | | |
1226 | | // Build body for the coroutine wrapper statement. |
1227 | 426 | Body = CoroutineBodyStmt::Create(Context, Builder); |
1228 | 426 | } |
1229 | | |
1230 | 569 | static CompoundStmt *buildCoroutineBody(Stmt *Body, ASTContext &Context) { |
1231 | 569 | if (auto *CS = dyn_cast<CompoundStmt>(Body)) |
1232 | 567 | return CS; |
1233 | | |
1234 | | // The body of the coroutine may be a try statement if it is in |
1235 | | // 'function-try-block' syntax. Here we wrap it into a compound |
1236 | | // statement for consistency. |
1237 | 2 | assert(isa<CXXTryStmt>(Body) && "Unimaged coroutine body type"); |
1238 | 2 | return CompoundStmt::Create(Context, {Body}, FPOptionsOverride(), |
1239 | 2 | SourceLocation(), SourceLocation()); |
1240 | 2 | } |
1241 | | |
1242 | | CoroutineStmtBuilder::CoroutineStmtBuilder(Sema &S, FunctionDecl &FD, |
1243 | | sema::FunctionScopeInfo &Fn, |
1244 | | Stmt *Body) |
1245 | 569 | : S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()), |
1246 | | IsPromiseDependentType( |
1247 | 569 | !Fn.CoroutinePromise || |
1248 | 569 | Fn.CoroutinePromise->getType()->isDependentType()) { |
1249 | 569 | this->Body = buildCoroutineBody(Body, S.getASTContext()); |
1250 | | |
1251 | 569 | for (auto KV : Fn.CoroutineParameterMoves) |
1252 | 332 | this->ParamMovesVector.push_back(KV.second); |
1253 | 569 | this->ParamMoves = this->ParamMovesVector; |
1254 | | |
1255 | 569 | if (!IsPromiseDependentType) { |
1256 | 466 | PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl(); |
1257 | 466 | assert(PromiseRecordDecl && "Type should have already been checked"); |
1258 | 466 | } |
1259 | 569 | this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend(); |
1260 | 569 | } |
1261 | | |
1262 | 456 | bool CoroutineStmtBuilder::buildStatements() { |
1263 | 456 | assert(this->IsValid && "coroutine already invalid"); |
1264 | 456 | this->IsValid = makeReturnObject(); |
1265 | 456 | if (this->IsValid && !IsPromiseDependentType454 ) |
1266 | 359 | buildDependentStatements(); |
1267 | 456 | return this->IsValid; |
1268 | 456 | } |
1269 | | |
1270 | 434 | bool CoroutineStmtBuilder::buildDependentStatements() { |
1271 | 434 | assert(this->IsValid && "coroutine already invalid"); |
1272 | 434 | assert(!this->IsPromiseDependentType && |
1273 | 434 | "coroutine cannot have a dependent promise type"); |
1274 | 434 | this->IsValid = makeOnException() && makeOnFallthrough()429 && |
1275 | 434 | makeGroDeclAndReturnStmt()425 && makeReturnOnAllocFailure()421 && |
1276 | 434 | makeNewAndDeleteExpr()415 ; |
1277 | 434 | return this->IsValid; |
1278 | 434 | } |
1279 | | |
1280 | 569 | bool CoroutineStmtBuilder::makePromiseStmt() { |
1281 | | // Form a declaration statement for the promise declaration, so that AST |
1282 | | // visitors can more easily find it. |
1283 | 569 | StmtResult PromiseStmt = |
1284 | 569 | S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(Fn.CoroutinePromise), Loc, Loc); |
1285 | 569 | if (PromiseStmt.isInvalid()) |
1286 | 0 | return false; |
1287 | | |
1288 | 569 | this->Promise = PromiseStmt.get(); |
1289 | 569 | return true; |
1290 | 569 | } |
1291 | | |
1292 | 569 | bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() { |
1293 | 569 | if (Fn.hasInvalidCoroutineSuspends()) |
1294 | 20 | return false; |
1295 | 549 | this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first); |
1296 | 549 | this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second); |
1297 | 549 | return true; |
1298 | 569 | } |
1299 | | |
1300 | | static bool diagReturnOnAllocFailure(Sema &S, Expr *E, |
1301 | | CXXRecordDecl *PromiseRecordDecl, |
1302 | 33 | FunctionScopeInfo &Fn) { |
1303 | 33 | auto Loc = E->getExprLoc(); |
1304 | 33 | if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) { |
1305 | 33 | auto *Decl = DeclRef->getDecl(); |
1306 | 33 | if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) { |
1307 | 33 | if (Method->isStatic()) |
1308 | 31 | return true; |
1309 | 2 | else |
1310 | 2 | Loc = Decl->getLocation(); |
1311 | 33 | } |
1312 | 33 | } |
1313 | | |
1314 | 2 | S.Diag( |
1315 | 2 | Loc, |
1316 | 2 | diag::err_coroutine_promise_get_return_object_on_allocation_failure) |
1317 | 2 | << PromiseRecordDecl; |
1318 | 2 | S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here) |
1319 | 2 | << Fn.getFirstCoroutineStmtKeyword(); |
1320 | 2 | return false; |
1321 | 33 | } |
1322 | | |
1323 | 421 | bool CoroutineStmtBuilder::makeReturnOnAllocFailure() { |
1324 | 421 | assert(!IsPromiseDependentType && |
1325 | 421 | "cannot make statement while the promise type is dependent"); |
1326 | | |
1327 | | // [dcl.fct.def.coroutine]p10 |
1328 | | // If a search for the name get_return_object_on_allocation_failure in |
1329 | | // the scope of the promise type ([class.member.lookup]) finds any |
1330 | | // declarations, then the result of a call to an allocation function used to |
1331 | | // obtain storage for the coroutine state is assumed to return nullptr if it |
1332 | | // fails to obtain storage, ... If the allocation function returns nullptr, |
1333 | | // ... and the return value is obtained by a call to |
1334 | | // T::get_return_object_on_allocation_failure(), where T is the |
1335 | | // promise type. |
1336 | 421 | DeclarationName DN = |
1337 | 421 | S.PP.getIdentifierInfo("get_return_object_on_allocation_failure"); |
1338 | 421 | LookupResult Found(S, DN, Loc, Sema::LookupMemberName); |
1339 | 421 | if (!S.LookupQualifiedName(Found, PromiseRecordDecl)) |
1340 | 388 | return true; |
1341 | | |
1342 | 33 | CXXScopeSpec SS; |
1343 | 33 | ExprResult DeclNameExpr = |
1344 | 33 | S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false); |
1345 | 33 | if (DeclNameExpr.isInvalid()) |
1346 | 0 | return false; |
1347 | | |
1348 | 33 | if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn)) |
1349 | 2 | return false; |
1350 | | |
1351 | 31 | ExprResult ReturnObjectOnAllocationFailure = |
1352 | 31 | S.BuildCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc); |
1353 | 31 | if (ReturnObjectOnAllocationFailure.isInvalid()) |
1354 | 0 | return false; |
1355 | | |
1356 | 31 | StmtResult ReturnStmt = |
1357 | 31 | S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get()); |
1358 | 31 | if (ReturnStmt.isInvalid()) { |
1359 | 4 | S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here) |
1360 | 4 | << DN; |
1361 | 4 | S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here) |
1362 | 4 | << Fn.getFirstCoroutineStmtKeyword(); |
1363 | 4 | return false; |
1364 | 4 | } |
1365 | | |
1366 | 27 | this->ReturnStmtOnAllocFailure = ReturnStmt.get(); |
1367 | 27 | return true; |
1368 | 31 | } |
1369 | | |
1370 | | // Collect placement arguments for allocation function of coroutine FD. |
1371 | | // Return true if we collect placement arguments succesfully. Return false, |
1372 | | // otherwise. |
1373 | | static bool collectPlacementArgs(Sema &S, FunctionDecl &FD, SourceLocation Loc, |
1374 | 34 | SmallVectorImpl<Expr *> &PlacementArgs) { |
1375 | 34 | if (auto *MD = dyn_cast<CXXMethodDecl>(&FD)) { |
1376 | 2 | if (MD->isImplicitObjectMemberFunction() && !isLambdaCallOperator(MD)0 ) { |
1377 | 0 | ExprResult ThisExpr = S.ActOnCXXThis(Loc); |
1378 | 0 | if (ThisExpr.isInvalid()) |
1379 | 0 | return false; |
1380 | 0 | ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get()); |
1381 | 0 | if (ThisExpr.isInvalid()) |
1382 | 0 | return false; |
1383 | 0 | PlacementArgs.push_back(ThisExpr.get()); |
1384 | 0 | } |
1385 | 2 | } |
1386 | | |
1387 | 37 | for (auto *PD : FD.parameters())34 { |
1388 | 37 | if (PD->getType()->isDependentType()) |
1389 | 0 | continue; |
1390 | | |
1391 | | // Build a reference to the parameter. |
1392 | 37 | auto PDLoc = PD->getLocation(); |
1393 | 37 | ExprResult PDRefExpr = |
1394 | 37 | S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(), |
1395 | 37 | ExprValueKind::VK_LValue, PDLoc); |
1396 | 37 | if (PDRefExpr.isInvalid()) |
1397 | 0 | return false; |
1398 | | |
1399 | 37 | PlacementArgs.push_back(PDRefExpr.get()); |
1400 | 37 | } |
1401 | | |
1402 | 34 | return true; |
1403 | 34 | } |
1404 | | |
1405 | 415 | bool CoroutineStmtBuilder::makeNewAndDeleteExpr() { |
1406 | | // Form and check allocation and deallocation calls. |
1407 | 415 | assert(!IsPromiseDependentType && |
1408 | 415 | "cannot make statement while the promise type is dependent"); |
1409 | 415 | QualType PromiseType = Fn.CoroutinePromise->getType(); |
1410 | | |
1411 | 415 | if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type)) |
1412 | 0 | return false; |
1413 | | |
1414 | 415 | const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr; |
1415 | | |
1416 | | // According to [dcl.fct.def.coroutine]p9, Lookup allocation functions using a |
1417 | | // parameter list composed of the requested size of the coroutine state being |
1418 | | // allocated, followed by the coroutine function's arguments. If a matching |
1419 | | // allocation function exists, use it. Otherwise, use an allocation function |
1420 | | // that just takes the requested size. |
1421 | | // |
1422 | | // [dcl.fct.def.coroutine]p9 |
1423 | | // An implementation may need to allocate additional storage for a |
1424 | | // coroutine. |
1425 | | // This storage is known as the coroutine state and is obtained by calling a |
1426 | | // non-array allocation function ([basic.stc.dynamic.allocation]). The |
1427 | | // allocation function's name is looked up by searching for it in the scope of |
1428 | | // the promise type. |
1429 | | // - If any declarations are found, overload resolution is performed on a |
1430 | | // function call created by assembling an argument list. The first argument is |
1431 | | // the amount of space requested, and has type std::size_t. The |
1432 | | // lvalues p1 ... pn are the succeeding arguments. |
1433 | | // |
1434 | | // ...where "p1 ... pn" are defined earlier as: |
1435 | | // |
1436 | | // [dcl.fct.def.coroutine]p3 |
1437 | | // The promise type of a coroutine is `std::coroutine_traits<R, P1, ..., |
1438 | | // Pn>` |
1439 | | // , where R is the return type of the function, and `P1, ..., Pn` are the |
1440 | | // sequence of types of the non-object function parameters, preceded by the |
1441 | | // type of the object parameter ([dcl.fct]) if the coroutine is a non-static |
1442 | | // member function. [dcl.fct.def.coroutine]p4 In the following, p_i is an |
1443 | | // lvalue of type P_i, where p1 denotes the object parameter and p_i+1 denotes |
1444 | | // the i-th non-object function parameter for a non-static member function, |
1445 | | // and p_i denotes the i-th function parameter otherwise. For a non-static |
1446 | | // member function, q_1 is an lvalue that denotes *this; any other q_i is an |
1447 | | // lvalue that denotes the parameter copy corresponding to p_i. |
1448 | | |
1449 | 415 | FunctionDecl *OperatorNew = nullptr; |
1450 | 415 | SmallVector<Expr *, 1> PlacementArgs; |
1451 | | |
1452 | 415 | const bool PromiseContainsNew = [this, &PromiseType]() -> bool { |
1453 | 415 | DeclarationName NewName = |
1454 | 415 | S.getASTContext().DeclarationNames.getCXXOperatorName(OO_New); |
1455 | 415 | LookupResult R(S, NewName, Loc, Sema::LookupOrdinaryName); |
1456 | | |
1457 | 415 | if (PromiseType->isRecordType()) |
1458 | 415 | S.LookupQualifiedName(R, PromiseType->getAsCXXRecordDecl()); |
1459 | | |
1460 | 415 | return !R.empty() && !R.isAmbiguous()35 ; |
1461 | 415 | }(); |
1462 | | |
1463 | | // Helper function to indicate whether the last lookup found the aligned |
1464 | | // allocation function. |
1465 | 415 | bool PassAlignment = S.getLangOpts().CoroAlignedAllocation; |
1466 | 415 | auto LookupAllocationFunction = [&](Sema::AllocationFunctionScope NewScope = |
1467 | 415 | Sema::AFS_Both, |
1468 | 415 | bool WithoutPlacementArgs = false, |
1469 | 447 | bool ForceNonAligned = false) { |
1470 | | // [dcl.fct.def.coroutine]p9 |
1471 | | // The allocation function's name is looked up by searching for it in the |
1472 | | // scope of the promise type. |
1473 | | // - If any declarations are found, ... |
1474 | | // - If no declarations are found in the scope of the promise type, a search |
1475 | | // is performed in the global scope. |
1476 | 447 | if (NewScope == Sema::AFS_Both) |
1477 | 415 | NewScope = PromiseContainsNew ? Sema::AFS_Class34 : Sema::AFS_Global381 ; |
1478 | | |
1479 | 447 | PassAlignment = !ForceNonAligned && S.getLangOpts().CoroAlignedAllocation443 ; |
1480 | 447 | FunctionDecl *UnusedResult = nullptr; |
1481 | 447 | S.FindAllocationFunctions(Loc, SourceRange(), NewScope, |
1482 | 447 | /*DeleteScope*/ Sema::AFS_Both, PromiseType, |
1483 | 447 | /*isArray*/ false, PassAlignment, |
1484 | 447 | WithoutPlacementArgs ? MultiExprArg{}9 |
1485 | 447 | : PlacementArgs438 , |
1486 | 447 | OperatorNew, UnusedResult, /*Diagnose*/ false); |
1487 | 447 | }; |
1488 | | |
1489 | | // We don't expect to call to global operator new with (size, p0, …, pn). |
1490 | | // So if we choose to lookup the allocation function in global scope, we |
1491 | | // shouldn't lookup placement arguments. |
1492 | 415 | if (PromiseContainsNew && !collectPlacementArgs(S, FD, Loc, PlacementArgs)34 ) |
1493 | 0 | return false; |
1494 | | |
1495 | 415 | LookupAllocationFunction(); |
1496 | | |
1497 | 415 | if (PromiseContainsNew && !PlacementArgs.empty()34 ) { |
1498 | | // [dcl.fct.def.coroutine]p9 |
1499 | | // If no viable function is found ([over.match.viable]), overload |
1500 | | // resolution |
1501 | | // is performed again on a function call created by passing just the amount |
1502 | | // of space required as an argument of type std::size_t. |
1503 | | // |
1504 | | // Proposed Change of [dcl.fct.def.coroutine]p9 in P2014R0: |
1505 | | // Otherwise, overload resolution is performed again on a function call |
1506 | | // created |
1507 | | // by passing the amount of space requested as an argument of type |
1508 | | // std::size_t as the first argument, and the requested alignment as |
1509 | | // an argument of type std:align_val_t as the second argument. |
1510 | 22 | if (!OperatorNew || |
1511 | 22 | (15 S.getLangOpts().CoroAlignedAllocation15 && !PassAlignment5 )) |
1512 | 9 | LookupAllocationFunction(/*NewScope*/ Sema::AFS_Class, |
1513 | 9 | /*WithoutPlacementArgs*/ true); |
1514 | 22 | } |
1515 | | |
1516 | | // Proposed Change of [dcl.fct.def.coroutine]p12 in P2014R0: |
1517 | | // Otherwise, overload resolution is performed again on a function call |
1518 | | // created |
1519 | | // by passing the amount of space requested as an argument of type |
1520 | | // std::size_t as the first argument, and the lvalues p1 ... pn as the |
1521 | | // succeeding arguments. Otherwise, overload resolution is performed again |
1522 | | // on a function call created by passing just the amount of space required as |
1523 | | // an argument of type std::size_t. |
1524 | | // |
1525 | | // So within the proposed change in P2014RO, the priority order of aligned |
1526 | | // allocation functions wiht promise_type is: |
1527 | | // |
1528 | | // void* operator new( std::size_t, std::align_val_t, placement_args... ); |
1529 | | // void* operator new( std::size_t, std::align_val_t); |
1530 | | // void* operator new( std::size_t, placement_args... ); |
1531 | | // void* operator new( std::size_t); |
1532 | | |
1533 | | // Helper variable to emit warnings. |
1534 | 415 | bool FoundNonAlignedInPromise = false; |
1535 | 415 | if (PromiseContainsNew && S.getLangOpts().CoroAlignedAllocation34 ) |
1536 | 12 | if (!OperatorNew || !PassAlignment) { |
1537 | 4 | FoundNonAlignedInPromise = OperatorNew; |
1538 | | |
1539 | 4 | LookupAllocationFunction(/*NewScope*/ Sema::AFS_Class, |
1540 | 4 | /*WithoutPlacementArgs*/ false, |
1541 | 4 | /*ForceNonAligned*/ true); |
1542 | | |
1543 | 4 | if (!OperatorNew && !PlacementArgs.empty()0 ) |
1544 | 0 | LookupAllocationFunction(/*NewScope*/ Sema::AFS_Class, |
1545 | 0 | /*WithoutPlacementArgs*/ true, |
1546 | 0 | /*ForceNonAligned*/ true); |
1547 | 4 | } |
1548 | | |
1549 | 415 | bool IsGlobalOverload = |
1550 | 415 | OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext())410 ; |
1551 | | // If we didn't find a class-local new declaration and non-throwing new |
1552 | | // was is required then we need to lookup the non-throwing global operator |
1553 | | // instead. |
1554 | 415 | if (RequiresNoThrowAlloc && (27 !OperatorNew27 || IsGlobalOverload25 )) { |
1555 | 19 | auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc); |
1556 | 19 | if (!StdNoThrow) |
1557 | 0 | return false; |
1558 | 19 | PlacementArgs = {StdNoThrow}; |
1559 | 19 | OperatorNew = nullptr; |
1560 | 19 | LookupAllocationFunction(Sema::AFS_Global); |
1561 | 19 | } |
1562 | | |
1563 | | // If we found a non-aligned allocation function in the promise_type, |
1564 | | // it indicates the user forgot to update the allocation function. Let's emit |
1565 | | // a warning here. |
1566 | 415 | if (FoundNonAlignedInPromise) { |
1567 | 4 | S.Diag(OperatorNew->getLocation(), |
1568 | 4 | diag::warn_non_aligned_allocation_function) |
1569 | 4 | << &FD; |
1570 | 4 | } |
1571 | | |
1572 | 415 | if (!OperatorNew) { |
1573 | 9 | if (PromiseContainsNew) |
1574 | 5 | S.Diag(Loc, diag::err_coroutine_unusable_new) << PromiseType << &FD; |
1575 | 4 | else if (RequiresNoThrowAlloc) |
1576 | 4 | S.Diag(Loc, diag::err_coroutine_unfound_nothrow_new) |
1577 | 4 | << &FD << S.getLangOpts().CoroAlignedAllocation; |
1578 | | |
1579 | 9 | return false; |
1580 | 9 | } |
1581 | | |
1582 | 406 | if (RequiresNoThrowAlloc) { |
1583 | 21 | const auto *FT = OperatorNew->getType()->castAs<FunctionProtoType>(); |
1584 | 21 | if (!FT->isNothrow(/*ResultIfDependent*/ false)) { |
1585 | 4 | S.Diag(OperatorNew->getLocation(), |
1586 | 4 | diag::err_coroutine_promise_new_requires_nothrow) |
1587 | 4 | << OperatorNew; |
1588 | 4 | S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required) |
1589 | 4 | << OperatorNew; |
1590 | 4 | return false; |
1591 | 4 | } |
1592 | 21 | } |
1593 | | |
1594 | 402 | FunctionDecl *OperatorDelete = nullptr; |
1595 | 402 | if (!findDeleteForPromise(S, Loc, PromiseType, OperatorDelete)) { |
1596 | | // FIXME: We should add an error here. According to: |
1597 | | // [dcl.fct.def.coroutine]p12 |
1598 | | // If no usual deallocation function is found, the program is ill-formed. |
1599 | 2 | return false; |
1600 | 2 | } |
1601 | | |
1602 | 400 | Expr *FramePtr = |
1603 | 400 | S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_frame, {}); |
1604 | | |
1605 | 400 | Expr *FrameSize = |
1606 | 400 | S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_size, {}); |
1607 | | |
1608 | 400 | Expr *FrameAlignment = nullptr; |
1609 | | |
1610 | 400 | if (S.getLangOpts().CoroAlignedAllocation) { |
1611 | 25 | FrameAlignment = |
1612 | 25 | S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_align, {}); |
1613 | | |
1614 | 25 | TypeSourceInfo *AlignValTy = getTypeSourceInfoForStdAlignValT(S, Loc); |
1615 | 25 | if (!AlignValTy) |
1616 | 0 | return false; |
1617 | | |
1618 | 25 | FrameAlignment = S.BuildCXXNamedCast(Loc, tok::kw_static_cast, AlignValTy, |
1619 | 25 | FrameAlignment, SourceRange(Loc, Loc), |
1620 | 25 | SourceRange(Loc, Loc)) |
1621 | 25 | .get(); |
1622 | 25 | } |
1623 | | |
1624 | | // Make new call. |
1625 | 400 | ExprResult NewRef = |
1626 | 400 | S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc); |
1627 | 400 | if (NewRef.isInvalid()) |
1628 | 0 | return false; |
1629 | | |
1630 | 400 | SmallVector<Expr *, 2> NewArgs(1, FrameSize); |
1631 | 400 | if (S.getLangOpts().CoroAlignedAllocation && PassAlignment25 ) |
1632 | 21 | NewArgs.push_back(FrameAlignment); |
1633 | | |
1634 | 400 | if (OperatorNew->getNumParams() > NewArgs.size()) |
1635 | 27 | llvm::append_range(NewArgs, PlacementArgs); |
1636 | | |
1637 | 400 | ExprResult NewExpr = |
1638 | 400 | S.BuildCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc); |
1639 | 400 | NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false); |
1640 | 400 | if (NewExpr.isInvalid()) |
1641 | 0 | return false; |
1642 | | |
1643 | | // Make delete call. |
1644 | | |
1645 | 400 | QualType OpDeleteQualType = OperatorDelete->getType(); |
1646 | | |
1647 | 400 | ExprResult DeleteRef = |
1648 | 400 | S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc); |
1649 | 400 | if (DeleteRef.isInvalid()) |
1650 | 0 | return false; |
1651 | | |
1652 | 400 | Expr *CoroFree = |
1653 | 400 | S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_free, {FramePtr}); |
1654 | | |
1655 | 400 | SmallVector<Expr *, 2> DeleteArgs{CoroFree}; |
1656 | | |
1657 | | // [dcl.fct.def.coroutine]p12 |
1658 | | // The selected deallocation function shall be called with the address of |
1659 | | // the block of storage to be reclaimed as its first argument. If a |
1660 | | // deallocation function with a parameter of type std::size_t is |
1661 | | // used, the size of the block is passed as the corresponding argument. |
1662 | 400 | const auto *OpDeleteType = |
1663 | 400 | OpDeleteQualType.getTypePtr()->castAs<FunctionProtoType>(); |
1664 | 400 | if (OpDeleteType->getNumParams() > DeleteArgs.size() && |
1665 | 400 | S.getASTContext().hasSameUnqualifiedType( |
1666 | 28 | OpDeleteType->getParamType(DeleteArgs.size()), FrameSize->getType())) |
1667 | 8 | DeleteArgs.push_back(FrameSize); |
1668 | | |
1669 | | // Proposed Change of [dcl.fct.def.coroutine]p12 in P2014R0: |
1670 | | // If deallocation function lookup finds a usual deallocation function with |
1671 | | // a pointer parameter, size parameter and alignment parameter then this |
1672 | | // will be the selected deallocation function, otherwise if lookup finds a |
1673 | | // usual deallocation function with both a pointer parameter and a size |
1674 | | // parameter, then this will be the selected deallocation function. |
1675 | | // Otherwise, if lookup finds a usual deallocation function with only a |
1676 | | // pointer parameter, then this will be the selected deallocation |
1677 | | // function. |
1678 | | // |
1679 | | // So we are not forced to pass alignment to the deallocation function. |
1680 | 400 | if (S.getLangOpts().CoroAlignedAllocation && |
1681 | 400 | OpDeleteType->getNumParams() > DeleteArgs.size()25 && |
1682 | 400 | S.getASTContext().hasSameUnqualifiedType( |
1683 | 22 | OpDeleteType->getParamType(DeleteArgs.size()), |
1684 | 22 | FrameAlignment->getType())) |
1685 | 22 | DeleteArgs.push_back(FrameAlignment); |
1686 | | |
1687 | 400 | ExprResult DeleteExpr = |
1688 | 400 | S.BuildCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc); |
1689 | 400 | DeleteExpr = |
1690 | 400 | S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false); |
1691 | 400 | if (DeleteExpr.isInvalid()) |
1692 | 0 | return false; |
1693 | | |
1694 | 400 | this->Allocate = NewExpr.get(); |
1695 | 400 | this->Deallocate = DeleteExpr.get(); |
1696 | | |
1697 | 400 | return true; |
1698 | 400 | } |
1699 | | |
1700 | 429 | bool CoroutineStmtBuilder::makeOnFallthrough() { |
1701 | 429 | assert(!IsPromiseDependentType && |
1702 | 429 | "cannot make statement while the promise type is dependent"); |
1703 | | |
1704 | | // [dcl.fct.def.coroutine]/p6 |
1705 | | // If searches for the names return_void and return_value in the scope of |
1706 | | // the promise type each find any declarations, the program is ill-formed. |
1707 | | // [Note 1: If return_void is found, flowing off the end of a coroutine is |
1708 | | // equivalent to a co_return with no operand. Otherwise, flowing off the end |
1709 | | // of a coroutine results in undefined behavior ([stmt.return.coroutine]). — |
1710 | | // end note] |
1711 | 429 | bool HasRVoid, HasRValue; |
1712 | 429 | LookupResult LRVoid = |
1713 | 429 | lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid); |
1714 | 429 | LookupResult LRValue = |
1715 | 429 | lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue); |
1716 | | |
1717 | 429 | StmtResult Fallthrough; |
1718 | 429 | if (HasRVoid && HasRValue268 ) { |
1719 | | // FIXME Improve this diagnostic |
1720 | 4 | S.Diag(FD.getLocation(), |
1721 | 4 | diag::err_coroutine_promise_incompatible_return_functions) |
1722 | 4 | << PromiseRecordDecl; |
1723 | 4 | S.Diag(LRVoid.getRepresentativeDecl()->getLocation(), |
1724 | 4 | diag::note_member_first_declared_here) |
1725 | 4 | << LRVoid.getLookupName(); |
1726 | 4 | S.Diag(LRValue.getRepresentativeDecl()->getLocation(), |
1727 | 4 | diag::note_member_first_declared_here) |
1728 | 4 | << LRValue.getLookupName(); |
1729 | 4 | return false; |
1730 | 425 | } else if (!HasRVoid && !HasRValue161 ) { |
1731 | | // We need to set 'Fallthrough'. Otherwise the other analysis part might |
1732 | | // think the coroutine has defined a return_value method. So it might emit |
1733 | | // **false** positive warning. e.g., |
1734 | | // |
1735 | | // promise_without_return_func foo() { |
1736 | | // co_await something(); |
1737 | | // } |
1738 | | // |
1739 | | // Then AnalysisBasedWarning would emit a warning about `foo()` lacking a |
1740 | | // co_return statements, which isn't correct. |
1741 | 10 | Fallthrough = S.ActOnNullStmt(PromiseRecordDecl->getLocation()); |
1742 | 10 | if (Fallthrough.isInvalid()) |
1743 | 0 | return false; |
1744 | 415 | } else if (HasRVoid) { |
1745 | 264 | Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr, |
1746 | 264 | /*IsImplicit*/false); |
1747 | 264 | Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get()); |
1748 | 264 | if (Fallthrough.isInvalid()) |
1749 | 0 | return false; |
1750 | 264 | } |
1751 | | |
1752 | 425 | this->OnFallthrough = Fallthrough.get(); |
1753 | 425 | return true; |
1754 | 429 | } |
1755 | | |
1756 | 434 | bool CoroutineStmtBuilder::makeOnException() { |
1757 | | // Try to form 'p.unhandled_exception();' |
1758 | 434 | assert(!IsPromiseDependentType && |
1759 | 434 | "cannot make statement while the promise type is dependent"); |
1760 | | |
1761 | 434 | const bool RequireUnhandledException = S.getLangOpts().CXXExceptions; |
1762 | | |
1763 | 434 | if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) { |
1764 | 26 | auto DiagID = |
1765 | 26 | RequireUnhandledException |
1766 | 26 | ? diag::err_coroutine_promise_unhandled_exception_required4 |
1767 | 26 | : diag:: |
1768 | 22 | warn_coroutine_promise_unhandled_exception_required_with_exceptions; |
1769 | 26 | S.Diag(Loc, DiagID) << PromiseRecordDecl; |
1770 | 26 | S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here) |
1771 | 26 | << PromiseRecordDecl; |
1772 | 26 | return !RequireUnhandledException; |
1773 | 26 | } |
1774 | | |
1775 | | // If exceptions are disabled, don't try to build OnException. |
1776 | 408 | if (!S.getLangOpts().CXXExceptions) |
1777 | 161 | return true; |
1778 | | |
1779 | 247 | ExprResult UnhandledException = buildPromiseCall( |
1780 | 247 | S, Fn.CoroutinePromise, Loc, "unhandled_exception", std::nullopt); |
1781 | 247 | UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc, |
1782 | 247 | /*DiscardedValue*/ false); |
1783 | 247 | if (UnhandledException.isInvalid()) |
1784 | 0 | return false; |
1785 | | |
1786 | | // Since the body of the coroutine will be wrapped in try-catch, it will |
1787 | | // be incompatible with SEH __try if present in a function. |
1788 | 247 | if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) { |
1789 | 1 | S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions); |
1790 | 1 | S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here) |
1791 | 1 | << Fn.getFirstCoroutineStmtKeyword(); |
1792 | 1 | return false; |
1793 | 1 | } |
1794 | | |
1795 | 246 | this->OnException = UnhandledException.get(); |
1796 | 246 | return true; |
1797 | 247 | } |
1798 | | |
1799 | 456 | bool CoroutineStmtBuilder::makeReturnObject() { |
1800 | | // [dcl.fct.def.coroutine]p7 |
1801 | | // The expression promise.get_return_object() is used to initialize the |
1802 | | // returned reference or prvalue result object of a call to a coroutine. |
1803 | 456 | ExprResult ReturnObject = buildPromiseCall(S, Fn.CoroutinePromise, Loc, |
1804 | 456 | "get_return_object", std::nullopt); |
1805 | 456 | if (ReturnObject.isInvalid()) |
1806 | 2 | return false; |
1807 | | |
1808 | 454 | this->ReturnValue = ReturnObject.get(); |
1809 | 454 | return true; |
1810 | 456 | } |
1811 | | |
1812 | 4 | static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn) { |
1813 | 4 | if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) { |
1814 | 4 | auto *MethodDecl = MbrRef->getMethodDecl(); |
1815 | 4 | S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here) |
1816 | 4 | << MethodDecl; |
1817 | 4 | } |
1818 | 4 | S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here) |
1819 | 4 | << Fn.getFirstCoroutineStmtKeyword(); |
1820 | 4 | } |
1821 | | |
1822 | 425 | bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() { |
1823 | 425 | assert(!IsPromiseDependentType && |
1824 | 425 | "cannot make statement while the promise type is dependent"); |
1825 | 425 | assert(this->ReturnValue && "ReturnValue must be already formed"); |
1826 | | |
1827 | 425 | QualType const GroType = this->ReturnValue->getType(); |
1828 | 425 | assert(!GroType->isDependentType() && |
1829 | 425 | "get_return_object type must no longer be dependent"); |
1830 | | |
1831 | 425 | QualType const FnRetType = FD.getReturnType(); |
1832 | 425 | assert(!FnRetType->isDependentType() && |
1833 | 425 | "get_return_object type must no longer be dependent"); |
1834 | | |
1835 | | // The call to get_return_object is sequenced before the call to |
1836 | | // initial_suspend and is invoked at most once, but there are caveats |
1837 | | // regarding on whether the prvalue result object may be initialized |
1838 | | // directly/eager or delayed, depending on the types involved. |
1839 | | // |
1840 | | // More info at https://github.com/cplusplus/papers/issues/1414 |
1841 | 425 | bool GroMatchesRetType = S.getASTContext().hasSameType(GroType, FnRetType); |
1842 | | |
1843 | 425 | if (FnRetType->isVoidType()) { |
1844 | 121 | ExprResult Res = |
1845 | 121 | S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false); |
1846 | 121 | if (Res.isInvalid()) |
1847 | 0 | return false; |
1848 | | |
1849 | 121 | if (!GroMatchesRetType) |
1850 | 0 | this->ResultDecl = Res.get(); |
1851 | 121 | return true; |
1852 | 121 | } |
1853 | | |
1854 | 304 | if (GroType->isVoidType()) { |
1855 | | // Trigger a nice error message. |
1856 | 2 | InitializedEntity Entity = |
1857 | 2 | InitializedEntity::InitializeResult(Loc, FnRetType); |
1858 | 2 | S.PerformCopyInitialization(Entity, SourceLocation(), ReturnValue); |
1859 | 2 | noteMemberDeclaredHere(S, ReturnValue, Fn); |
1860 | 2 | return false; |
1861 | 2 | } |
1862 | | |
1863 | 302 | StmtResult ReturnStmt; |
1864 | 302 | clang::VarDecl *GroDecl = nullptr; |
1865 | 302 | if (GroMatchesRetType) { |
1866 | 295 | ReturnStmt = S.BuildReturnStmt(Loc, ReturnValue); |
1867 | 295 | } else { |
1868 | 7 | GroDecl = VarDecl::Create( |
1869 | 7 | S.Context, &FD, FD.getLocation(), FD.getLocation(), |
1870 | 7 | &S.PP.getIdentifierTable().get("__coro_gro"), GroType, |
1871 | 7 | S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None); |
1872 | 7 | GroDecl->setImplicit(); |
1873 | | |
1874 | 7 | S.CheckVariableDeclarationType(GroDecl); |
1875 | 7 | if (GroDecl->isInvalidDecl()) |
1876 | 0 | return false; |
1877 | | |
1878 | 7 | InitializedEntity Entity = InitializedEntity::InitializeVariable(GroDecl); |
1879 | 7 | ExprResult Res = |
1880 | 7 | S.PerformCopyInitialization(Entity, SourceLocation(), ReturnValue); |
1881 | 7 | if (Res.isInvalid()) |
1882 | 0 | return false; |
1883 | | |
1884 | 7 | Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false); |
1885 | 7 | if (Res.isInvalid()) |
1886 | 0 | return false; |
1887 | | |
1888 | 7 | S.AddInitializerToDecl(GroDecl, Res.get(), |
1889 | 7 | /*DirectInit=*/false); |
1890 | | |
1891 | 7 | S.FinalizeDeclaration(GroDecl); |
1892 | | |
1893 | | // Form a declaration statement for the return declaration, so that AST |
1894 | | // visitors can more easily find it. |
1895 | 7 | StmtResult GroDeclStmt = |
1896 | 7 | S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc); |
1897 | 7 | if (GroDeclStmt.isInvalid()) |
1898 | 0 | return false; |
1899 | | |
1900 | 7 | this->ResultDecl = GroDeclStmt.get(); |
1901 | | |
1902 | 7 | ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc); |
1903 | 7 | if (declRef.isInvalid()) |
1904 | 0 | return false; |
1905 | | |
1906 | 7 | ReturnStmt = S.BuildReturnStmt(Loc, declRef.get()); |
1907 | 7 | } |
1908 | | |
1909 | 302 | if (ReturnStmt.isInvalid()) { |
1910 | 2 | noteMemberDeclaredHere(S, ReturnValue, Fn); |
1911 | 2 | return false; |
1912 | 2 | } |
1913 | | |
1914 | 300 | if (!GroMatchesRetType && |
1915 | 300 | cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl5 ) |
1916 | 0 | GroDecl->setNRVOVariable(true); |
1917 | | |
1918 | 300 | this->ReturnStmt = ReturnStmt.get(); |
1919 | 300 | return true; |
1920 | 302 | } |
1921 | | |
1922 | | // Create a static_cast\<T&&>(expr). |
1923 | 103 | static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) { |
1924 | 103 | if (T.isNull()) |
1925 | 103 | T = E->getType(); |
1926 | 103 | QualType TargetType = S.BuildReferenceType( |
1927 | 103 | T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName()); |
1928 | 103 | SourceLocation ExprLoc = E->getBeginLoc(); |
1929 | 103 | TypeSourceInfo *TargetLoc = |
1930 | 103 | S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc); |
1931 | | |
1932 | 103 | return S |
1933 | 103 | .BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E, |
1934 | 103 | SourceRange(ExprLoc, ExprLoc), E->getSourceRange()) |
1935 | 103 | .get(); |
1936 | 103 | } |
1937 | | |
1938 | | /// Build a variable declaration for move parameter. |
1939 | | static VarDecl *buildVarDecl(Sema &S, SourceLocation Loc, QualType Type, |
1940 | 358 | IdentifierInfo *II) { |
1941 | 358 | TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc); |
1942 | 358 | VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type, |
1943 | 358 | TInfo, SC_None); |
1944 | 358 | Decl->setImplicit(); |
1945 | 358 | return Decl; |
1946 | 358 | } |
1947 | | |
1948 | | // Build statements that move coroutine function parameters to the coroutine |
1949 | | // frame, and store them on the function scope info. |
1950 | 611 | bool Sema::buildCoroutineParameterMoves(SourceLocation Loc) { |
1951 | 611 | assert(isa<FunctionDecl>(CurContext) && "not in a function scope"); |
1952 | 611 | auto *FD = cast<FunctionDecl>(CurContext); |
1953 | | |
1954 | 611 | auto *ScopeInfo = getCurFunction(); |
1955 | 611 | if (!ScopeInfo->CoroutineParameterMoves.empty()) |
1956 | 2 | return false; |
1957 | | |
1958 | | // [dcl.fct.def.coroutine]p13 |
1959 | | // When a coroutine is invoked, after initializing its parameters |
1960 | | // ([expr.call]), a copy is created for each coroutine parameter. For a |
1961 | | // parameter of type cv T, the copy is a variable of type cv T with |
1962 | | // automatic storage duration that is direct-initialized from an xvalue of |
1963 | | // type T referring to the parameter. |
1964 | 609 | for (auto *PD : FD->parameters()) { |
1965 | 442 | if (PD->getType()->isDependentType()) |
1966 | 84 | continue; |
1967 | | |
1968 | | // Preserve the referenced state for unused parameter diagnostics. |
1969 | 358 | bool DeclReferenced = PD->isReferenced(); |
1970 | | |
1971 | 358 | ExprResult PDRefExpr = |
1972 | 358 | BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(), |
1973 | 358 | ExprValueKind::VK_LValue, Loc); // FIXME: scope? |
1974 | | |
1975 | 358 | PD->setReferenced(DeclReferenced); |
1976 | | |
1977 | 358 | if (PDRefExpr.isInvalid()) |
1978 | 0 | return false; |
1979 | | |
1980 | 358 | Expr *CExpr = nullptr; |
1981 | 358 | if (PD->getType()->getAsCXXRecordDecl() || |
1982 | 358 | PD->getType()->isRValueReferenceType()274 ) |
1983 | 103 | CExpr = castForMoving(*this, PDRefExpr.get()); |
1984 | 255 | else |
1985 | 255 | CExpr = PDRefExpr.get(); |
1986 | | // [dcl.fct.def.coroutine]p13 |
1987 | | // The initialization and destruction of each parameter copy occurs in the |
1988 | | // context of the called coroutine. |
1989 | 358 | auto *D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier()); |
1990 | 358 | AddInitializerToDecl(D, CExpr, /*DirectInit=*/true); |
1991 | | |
1992 | | // Convert decl to a statement. |
1993 | 358 | StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc); |
1994 | 358 | if (Stmt.isInvalid()) |
1995 | 0 | return false; |
1996 | | |
1997 | 358 | ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get())); |
1998 | 358 | } |
1999 | 609 | return true; |
2000 | 609 | } |
2001 | | |
2002 | 87 | StmtResult Sema::BuildCoroutineBodyStmt(CoroutineBodyStmt::CtorArgs Args) { |
2003 | 87 | CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args); |
2004 | 87 | if (!Res) |
2005 | 0 | return StmtError(); |
2006 | 87 | return Res; |
2007 | 87 | } |
2008 | | |
2009 | | ClassTemplateDecl *Sema::lookupCoroutineTraits(SourceLocation KwLoc, |
2010 | 506 | SourceLocation FuncLoc) { |
2011 | 506 | if (StdCoroutineTraitsCache) |
2012 | 392 | return StdCoroutineTraitsCache; |
2013 | | |
2014 | 114 | IdentifierInfo const &TraitIdent = |
2015 | 114 | PP.getIdentifierTable().get("coroutine_traits"); |
2016 | | |
2017 | 114 | NamespaceDecl *StdSpace = getStdNamespace(); |
2018 | 114 | LookupResult Result(*this, &TraitIdent, FuncLoc, LookupOrdinaryName); |
2019 | 114 | bool Found = StdSpace && LookupQualifiedName(Result, StdSpace)106 ; |
2020 | | |
2021 | 114 | if (!Found) { |
2022 | | // The goggles, we found nothing! |
2023 | 8 | Diag(KwLoc, diag::err_implied_coroutine_type_not_found) |
2024 | 8 | << "std::coroutine_traits"; |
2025 | 8 | return nullptr; |
2026 | 8 | } |
2027 | | |
2028 | | // coroutine_traits is required to be a class template. |
2029 | 106 | StdCoroutineTraitsCache = Result.getAsSingle<ClassTemplateDecl>(); |
2030 | 106 | if (!StdCoroutineTraitsCache) { |
2031 | 0 | Result.suppressDiagnostics(); |
2032 | 0 | NamedDecl *Found = *Result.begin(); |
2033 | 0 | Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits); |
2034 | 0 | return nullptr; |
2035 | 0 | } |
2036 | | |
2037 | 106 | return StdCoroutineTraitsCache; |
2038 | 106 | } |