1 | //===--- SemaLambda.cpp - Semantic Analysis for C++11 Lambdas -------------===// |
---|---|
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++ lambda expressions. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | #include "clang/Sema/SemaLambda.h" |
13 | #include "TypeLocBuilder.h" |
14 | #include "clang/AST/ASTLambda.h" |
15 | #include "clang/AST/CXXInheritance.h" |
16 | #include "clang/AST/ExprCXX.h" |
17 | #include "clang/AST/MangleNumberingContext.h" |
18 | #include "clang/Basic/TargetInfo.h" |
19 | #include "clang/Sema/DeclSpec.h" |
20 | #include "clang/Sema/Initialization.h" |
21 | #include "clang/Sema/Lookup.h" |
22 | #include "clang/Sema/Scope.h" |
23 | #include "clang/Sema/ScopeInfo.h" |
24 | #include "clang/Sema/SemaARM.h" |
25 | #include "clang/Sema/SemaCUDA.h" |
26 | #include "clang/Sema/SemaInternal.h" |
27 | #include "clang/Sema/SemaOpenMP.h" |
28 | #include "clang/Sema/SemaSYCL.h" |
29 | #include "clang/Sema/Template.h" |
30 | #include "llvm/ADT/STLExtras.h" |
31 | #include <optional> |
32 | using namespace clang; |
33 | using namespace sema; |
34 | |
35 | /// Examines the FunctionScopeInfo stack to determine the nearest |
36 | /// enclosing lambda (to the current lambda) that is 'capture-ready' for |
37 | /// the variable referenced in the current lambda (i.e. \p VarToCapture). |
38 | /// If successful, returns the index into Sema's FunctionScopeInfo stack |
39 | /// of the capture-ready lambda's LambdaScopeInfo. |
40 | /// |
41 | /// Climbs down the stack of lambdas (deepest nested lambda - i.e. current |
42 | /// lambda - is on top) to determine the index of the nearest enclosing/outer |
43 | /// lambda that is ready to capture the \p VarToCapture being referenced in |
44 | /// the current lambda. |
45 | /// As we climb down the stack, we want the index of the first such lambda - |
46 | /// that is the lambda with the highest index that is 'capture-ready'. |
47 | /// |
48 | /// A lambda 'L' is capture-ready for 'V' (var or this) if: |
49 | /// - its enclosing context is non-dependent |
50 | /// - and if the chain of lambdas between L and the lambda in which |
51 | /// V is potentially used (i.e. the lambda at the top of the scope info |
52 | /// stack), can all capture or have already captured V. |
53 | /// If \p VarToCapture is 'null' then we are trying to capture 'this'. |
54 | /// |
55 | /// Note that a lambda that is deemed 'capture-ready' still needs to be checked |
56 | /// for whether it is 'capture-capable' (see |
57 | /// getStackIndexOfNearestEnclosingCaptureCapableLambda), before it can truly |
58 | /// capture. |
59 | /// |
60 | /// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a |
61 | /// LambdaScopeInfo inherits from). The current/deepest/innermost lambda |
62 | /// is at the top of the stack and has the highest index. |
63 | /// \param VarToCapture - the variable to capture. If NULL, capture 'this'. |
64 | /// |
65 | /// \returns An UnsignedOrNone Index that if evaluates to 'true' |
66 | /// contains the index (into Sema's FunctionScopeInfo stack) of the innermost |
67 | /// lambda which is capture-ready. If the return value evaluates to 'false' |
68 | /// then no lambda is capture-ready for \p VarToCapture. |
69 | |
70 | static inline UnsignedOrNone getStackIndexOfNearestEnclosingCaptureReadyLambda( |
71 | ArrayRef<const clang::sema::FunctionScopeInfo *> FunctionScopes, |
72 | ValueDecl *VarToCapture) { |
73 | // Label failure to capture. |
74 | const UnsignedOrNone NoLambdaIsCaptureReady = std::nullopt; |
75 | |
76 | // Ignore all inner captured regions. |
77 | unsigned CurScopeIndex = FunctionScopes.size() - 1; |
78 | while (CurScopeIndex > 0 && isa<clang::sema::CapturedRegionScopeInfo>( |
79 | Val: FunctionScopes[CurScopeIndex])) |
80 | --CurScopeIndex; |
81 | assert( |
82 | isa<clang::sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]) && |
83 | "The function on the top of sema's function-info stack must be a lambda"); |
84 | |
85 | // If VarToCapture is null, we are attempting to capture 'this'. |
86 | const bool IsCapturingThis = !VarToCapture; |
87 | const bool IsCapturingVariable = !IsCapturingThis; |
88 | |
89 | // Start with the current lambda at the top of the stack (highest index). |
90 | DeclContext *EnclosingDC = |
91 | cast<sema::LambdaScopeInfo>(Val: FunctionScopes[CurScopeIndex])->CallOperator; |
92 | |
93 | do { |
94 | const clang::sema::LambdaScopeInfo *LSI = |
95 | cast<sema::LambdaScopeInfo>(Val: FunctionScopes[CurScopeIndex]); |
96 | // IF we have climbed down to an intervening enclosing lambda that contains |
97 | // the variable declaration - it obviously can/must not capture the |
98 | // variable. |
99 | // Since its enclosing DC is dependent, all the lambdas between it and the |
100 | // innermost nested lambda are dependent (otherwise we wouldn't have |
101 | // arrived here) - so we don't yet have a lambda that can capture the |
102 | // variable. |
103 | if (IsCapturingVariable && |
104 | VarToCapture->getDeclContext()->Equals(EnclosingDC)) |
105 | return NoLambdaIsCaptureReady; |
106 | |
107 | // For an enclosing lambda to be capture ready for an entity, all |
108 | // intervening lambda's have to be able to capture that entity. If even |
109 | // one of the intervening lambda's is not capable of capturing the entity |
110 | // then no enclosing lambda can ever capture that entity. |
111 | // For e.g. |
112 | // const int x = 10; |
113 | // [=](auto a) { #1 |
114 | // [](auto b) { #2 <-- an intervening lambda that can never capture 'x' |
115 | // [=](auto c) { #3 |
116 | // f(x, c); <-- can not lead to x's speculative capture by #1 or #2 |
117 | // }; }; }; |
118 | // If they do not have a default implicit capture, check to see |
119 | // if the entity has already been explicitly captured. |
120 | // If even a single dependent enclosing lambda lacks the capability |
121 | // to ever capture this variable, there is no further enclosing |
122 | // non-dependent lambda that can capture this variable. |
123 | if (LSI->ImpCaptureStyle == sema::LambdaScopeInfo::ImpCap_None) { |
124 | if (IsCapturingVariable && !LSI->isCaptured(VarToCapture)) |
125 | return NoLambdaIsCaptureReady; |
126 | if (IsCapturingThis && !LSI->isCXXThisCaptured()) |
127 | return NoLambdaIsCaptureReady; |
128 | } |
129 | EnclosingDC = getLambdaAwareParentOfDeclContext(DC: EnclosingDC); |
130 | |
131 | assert(CurScopeIndex); |
132 | --CurScopeIndex; |
133 | } while (!EnclosingDC->isTranslationUnit() && |
134 | EnclosingDC->isDependentContext() && |
135 | isLambdaCallOperator(DC: EnclosingDC)); |
136 | |
137 | assert(CurScopeIndex < (FunctionScopes.size() - 1)); |
138 | // If the enclosingDC is not dependent, then the immediately nested lambda |
139 | // (one index above) is capture-ready. |
140 | if (!EnclosingDC->isDependentContext()) |
141 | return CurScopeIndex + 1; |
142 | return NoLambdaIsCaptureReady; |
143 | } |
144 | |
145 | /// Examines the FunctionScopeInfo stack to determine the nearest |
146 | /// enclosing lambda (to the current lambda) that is 'capture-capable' for |
147 | /// the variable referenced in the current lambda (i.e. \p VarToCapture). |
148 | /// If successful, returns the index into Sema's FunctionScopeInfo stack |
149 | /// of the capture-capable lambda's LambdaScopeInfo. |
150 | /// |
151 | /// Given the current stack of lambdas being processed by Sema and |
152 | /// the variable of interest, to identify the nearest enclosing lambda (to the |
153 | /// current lambda at the top of the stack) that can truly capture |
154 | /// a variable, it has to have the following two properties: |
155 | /// a) 'capture-ready' - be the innermost lambda that is 'capture-ready': |
156 | /// - climb down the stack (i.e. starting from the innermost and examining |
157 | /// each outer lambda step by step) checking if each enclosing |
158 | /// lambda can either implicitly or explicitly capture the variable. |
159 | /// Record the first such lambda that is enclosed in a non-dependent |
160 | /// context. If no such lambda currently exists return failure. |
161 | /// b) 'capture-capable' - make sure the 'capture-ready' lambda can truly |
162 | /// capture the variable by checking all its enclosing lambdas: |
163 | /// - check if all outer lambdas enclosing the 'capture-ready' lambda |
164 | /// identified above in 'a' can also capture the variable (this is done |
165 | /// via tryCaptureVariable for variables and CheckCXXThisCapture for |
166 | /// 'this' by passing in the index of the Lambda identified in step 'a') |
167 | /// |
168 | /// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a |
169 | /// LambdaScopeInfo inherits from). The current/deepest/innermost lambda |
170 | /// is at the top of the stack. |
171 | /// |
172 | /// \param VarToCapture - the variable to capture. If NULL, capture 'this'. |
173 | /// |
174 | /// |
175 | /// \returns An UnsignedOrNone Index that if evaluates to 'true' |
176 | /// contains the index (into Sema's FunctionScopeInfo stack) of the innermost |
177 | /// lambda which is capture-capable. If the return value evaluates to 'false' |
178 | /// then no lambda is capture-capable for \p VarToCapture. |
179 | |
180 | UnsignedOrNone clang::getStackIndexOfNearestEnclosingCaptureCapableLambda( |
181 | ArrayRef<const sema::FunctionScopeInfo *> FunctionScopes, |
182 | ValueDecl *VarToCapture, Sema &S) { |
183 | |
184 | const UnsignedOrNone NoLambdaIsCaptureCapable = std::nullopt; |
185 | |
186 | const UnsignedOrNone OptionalStackIndex = |
187 | getStackIndexOfNearestEnclosingCaptureReadyLambda(FunctionScopes, |
188 | VarToCapture); |
189 | if (!OptionalStackIndex) |
190 | return NoLambdaIsCaptureCapable; |
191 | |
192 | const unsigned IndexOfCaptureReadyLambda = *OptionalStackIndex; |
193 | assert(((IndexOfCaptureReadyLambda != (FunctionScopes.size() - 1)) || |
194 | S.getCurGenericLambda()) && |
195 | "The capture ready lambda for a potential capture can only be the " |
196 | "current lambda if it is a generic lambda"); |
197 | |
198 | const sema::LambdaScopeInfo *const CaptureReadyLambdaLSI = |
199 | cast<sema::LambdaScopeInfo>(Val: FunctionScopes[IndexOfCaptureReadyLambda]); |
200 | |
201 | // If VarToCapture is null, we are attempting to capture 'this' |
202 | const bool IsCapturingThis = !VarToCapture; |
203 | const bool IsCapturingVariable = !IsCapturingThis; |
204 | |
205 | if (IsCapturingVariable) { |
206 | // Check if the capture-ready lambda can truly capture the variable, by |
207 | // checking whether all enclosing lambdas of the capture-ready lambda allow |
208 | // the capture - i.e. make sure it is capture-capable. |
209 | QualType CaptureType, DeclRefType; |
210 | const bool CanCaptureVariable = !S.tryCaptureVariable( |
211 | Var: VarToCapture, |
212 | /*ExprVarIsUsedInLoc*/ Loc: SourceLocation(), Kind: TryCaptureKind::Implicit, |
213 | /*EllipsisLoc*/ SourceLocation(), |
214 | /*BuildAndDiagnose*/ false, CaptureType, DeclRefType, |
215 | FunctionScopeIndexToStopAt: &IndexOfCaptureReadyLambda); |
216 | if (!CanCaptureVariable) |
217 | return NoLambdaIsCaptureCapable; |
218 | } else { |
219 | // Check if the capture-ready lambda can truly capture 'this' by checking |
220 | // whether all enclosing lambdas of the capture-ready lambda can capture |
221 | // 'this'. |
222 | const bool CanCaptureThis = |
223 | !S.CheckCXXThisCapture( |
224 | Loc: CaptureReadyLambdaLSI->PotentialThisCaptureLocation, |
225 | /*Explicit*/ false, /*BuildAndDiagnose*/ false, |
226 | FunctionScopeIndexToStopAt: &IndexOfCaptureReadyLambda); |
227 | if (!CanCaptureThis) |
228 | return NoLambdaIsCaptureCapable; |
229 | } |
230 | return IndexOfCaptureReadyLambda; |
231 | } |
232 | |
233 | static inline TemplateParameterList * |
234 | getGenericLambdaTemplateParameterList(LambdaScopeInfo *LSI, Sema &SemaRef) { |
235 | if (!LSI->GLTemplateParameterList && !LSI->TemplateParams.empty()) { |
236 | LSI->GLTemplateParameterList = TemplateParameterList::Create( |
237 | C: SemaRef.Context, |
238 | /*Template kw loc*/ TemplateLoc: SourceLocation(), |
239 | /*L angle loc*/ LAngleLoc: LSI->ExplicitTemplateParamsRange.getBegin(), |
240 | Params: LSI->TemplateParams, |
241 | /*R angle loc*/RAngleLoc: LSI->ExplicitTemplateParamsRange.getEnd(), |
242 | RequiresClause: LSI->RequiresClause.get()); |
243 | } |
244 | return LSI->GLTemplateParameterList; |
245 | } |
246 | |
247 | CXXRecordDecl * |
248 | Sema::createLambdaClosureType(SourceRange IntroducerRange, TypeSourceInfo *Info, |
249 | unsigned LambdaDependencyKind, |
250 | LambdaCaptureDefault CaptureDefault) { |
251 | DeclContext *DC = CurContext; |
252 | while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext())) |
253 | DC = DC->getParent(); |
254 | |
255 | bool IsGenericLambda = |
256 | Info && getGenericLambdaTemplateParameterList(LSI: getCurLambda(), SemaRef&: *this); |
257 | // Start constructing the lambda class. |
258 | CXXRecordDecl *Class = CXXRecordDecl::CreateLambda( |
259 | C: Context, DC, Info, Loc: IntroducerRange.getBegin(), DependencyKind: LambdaDependencyKind, |
260 | IsGeneric: IsGenericLambda, CaptureDefault); |
261 | DC->addDecl(Class); |
262 | |
263 | return Class; |
264 | } |
265 | |
266 | /// Determine whether the given context is or is enclosed in an inline |
267 | /// function. |
268 | static bool isInInlineFunction(const DeclContext *DC) { |
269 | while (!DC->isFileContext()) { |
270 | if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: DC)) |
271 | if (FD->isInlined()) |
272 | return true; |
273 | |
274 | DC = DC->getLexicalParent(); |
275 | } |
276 | |
277 | return false; |
278 | } |
279 | |
280 | std::tuple<MangleNumberingContext *, Decl *> |
281 | Sema::getCurrentMangleNumberContext(const DeclContext *DC) { |
282 | // Compute the context for allocating mangling numbers in the current |
283 | // expression, if the ABI requires them. |
284 | Decl *ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl; |
285 | |
286 | enum ContextKind { |
287 | Normal, |
288 | DefaultArgument, |
289 | DataMember, |
290 | InlineVariable, |
291 | TemplatedVariable, |
292 | Concept, |
293 | NonInlineInModulePurview |
294 | } Kind = Normal; |
295 | |
296 | bool IsInNonspecializedTemplate = |
297 | inTemplateInstantiation() || CurContext->isDependentContext(); |
298 | |
299 | // Default arguments of member function parameters that appear in a class |
300 | // definition, as well as the initializers of data members, receive special |
301 | // treatment. Identify them. |
302 | Kind = [&]() { |
303 | if (!ManglingContextDecl) |
304 | return Normal; |
305 | |
306 | if (auto *ND = dyn_cast<NamedDecl>(Val: ManglingContextDecl)) { |
307 | // See discussion in https://github.com/itanium-cxx-abi/cxx-abi/issues/186 |
308 | // |
309 | // zygoloid: |
310 | // Yeah, I think the only cases left where lambdas don't need a |
311 | // mangling are when they have (effectively) internal linkage or appear |
312 | // in a non-inline function in a non-module translation unit. |
313 | Module *M = ManglingContextDecl->getOwningModule(); |
314 | if (M && M->getTopLevelModule()->isNamedModuleUnit() && |
315 | ND->isExternallyVisible()) |
316 | return NonInlineInModulePurview; |
317 | } |
318 | |
319 | if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Val: ManglingContextDecl)) { |
320 | if (const DeclContext *LexicalDC |
321 | = Param->getDeclContext()->getLexicalParent()) |
322 | if (LexicalDC->isRecord()) |
323 | return DefaultArgument; |
324 | } else if (VarDecl *Var = dyn_cast<VarDecl>(Val: ManglingContextDecl)) { |
325 | if (Var->getMostRecentDecl()->isInline()) |
326 | return InlineVariable; |
327 | |
328 | if (Var->getDeclContext()->isRecord() && IsInNonspecializedTemplate) |
329 | return TemplatedVariable; |
330 | |
331 | if (Var->getDescribedVarTemplate()) |
332 | return TemplatedVariable; |
333 | |
334 | if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Val: Var)) { |
335 | if (!VTS->isExplicitSpecialization()) |
336 | return TemplatedVariable; |
337 | } |
338 | } else if (isa<FieldDecl>(Val: ManglingContextDecl)) { |
339 | return DataMember; |
340 | } else if (isa<ImplicitConceptSpecializationDecl>(Val: ManglingContextDecl)) { |
341 | return Concept; |
342 | } |
343 | |
344 | return Normal; |
345 | }(); |
346 | |
347 | // Itanium ABI [5.1.7]: |
348 | // In the following contexts [...] the one-definition rule requires closure |
349 | // types in different translation units to "correspond": |
350 | switch (Kind) { |
351 | case Normal: { |
352 | // -- the bodies of inline or templated functions |
353 | if ((IsInNonspecializedTemplate && |
354 | !(ManglingContextDecl && isa<ParmVarDecl>(Val: ManglingContextDecl))) || |
355 | isInInlineFunction(DC: CurContext)) { |
356 | while (auto *CD = dyn_cast<CapturedDecl>(Val: DC)) |
357 | DC = CD->getParent(); |
358 | return std::make_tuple(args: &Context.getManglingNumberContext(DC), args: nullptr); |
359 | } |
360 | |
361 | return std::make_tuple(args: nullptr, args: nullptr); |
362 | } |
363 | |
364 | case NonInlineInModulePurview: |
365 | case Concept: |
366 | // Concept definitions aren't code generated and thus aren't mangled, |
367 | // however the ManglingContextDecl is important for the purposes of |
368 | // re-forming the template argument list of the lambda for constraint |
369 | // evaluation. |
370 | case DataMember: |
371 | // -- default member initializers |
372 | case DefaultArgument: |
373 | // -- default arguments appearing in class definitions |
374 | case InlineVariable: |
375 | case TemplatedVariable: |
376 | // -- the initializers of inline or templated variables |
377 | return std::make_tuple( |
378 | args: &Context.getManglingNumberContext(ASTContext::NeedExtraManglingDecl, |
379 | D: ManglingContextDecl), |
380 | args&: ManglingContextDecl); |
381 | } |
382 | |
383 | llvm_unreachable("unexpected context"); |
384 | } |
385 | |
386 | static QualType |
387 | buildTypeForLambdaCallOperator(Sema &S, clang::CXXRecordDecl *Class, |
388 | TemplateParameterList *TemplateParams, |
389 | TypeSourceInfo *MethodTypeInfo) { |
390 | assert(MethodTypeInfo && "expected a non null type"); |
391 | |
392 | QualType MethodType = MethodTypeInfo->getType(); |
393 | // If a lambda appears in a dependent context or is a generic lambda (has |
394 | // template parameters) and has an 'auto' return type, deduce it to a |
395 | // dependent type. |
396 | if (Class->isDependentContext() || TemplateParams) { |
397 | const FunctionProtoType *FPT = MethodType->castAs<FunctionProtoType>(); |
398 | QualType Result = FPT->getReturnType(); |
399 | if (Result->isUndeducedType()) { |
400 | Result = S.SubstAutoTypeDependent(TypeWithAuto: Result); |
401 | MethodType = S.Context.getFunctionType(ResultTy: Result, Args: FPT->getParamTypes(), |
402 | EPI: FPT->getExtProtoInfo()); |
403 | } |
404 | } |
405 | return MethodType; |
406 | } |
407 | |
408 | // [C++2b] [expr.prim.lambda.closure] p4 |
409 | // Given a lambda with a lambda-capture, the type of the explicit object |
410 | // parameter, if any, of the lambda's function call operator (possibly |
411 | // instantiated from a function call operator template) shall be either: |
412 | // - the closure type, |
413 | // - class type publicly and unambiguously derived from the closure type, or |
414 | // - a reference to a possibly cv-qualified such type. |
415 | bool Sema::DiagnoseInvalidExplicitObjectParameterInLambda( |
416 | CXXMethodDecl *Method, SourceLocation CallLoc) { |
417 | if (!isLambdaCallWithExplicitObjectParameter(Method)) |
418 | return false; |
419 | CXXRecordDecl *RD = Method->getParent(); |
420 | if (Method->getType()->isDependentType()) |
421 | return false; |
422 | if (RD->isCapturelessLambda()) |
423 | return false; |
424 | |
425 | ParmVarDecl *Param = Method->getParamDecl(0); |
426 | QualType ExplicitObjectParameterType = Param->getType() |
427 | .getNonReferenceType() |
428 | .getUnqualifiedType() |
429 | .getDesugaredType(getASTContext()); |
430 | QualType LambdaType = getASTContext().getRecordType(RD); |
431 | if (LambdaType == ExplicitObjectParameterType) |
432 | return false; |
433 | |
434 | // Don't check the same instantiation twice. |
435 | // |
436 | // If this call operator is ill-formed, there is no point in issuing |
437 | // a diagnostic every time it is called because the problem is in the |
438 | // definition of the derived type, not at the call site. |
439 | // |
440 | // FIXME: Move this check to where we instantiate the method? This should |
441 | // be possible, but the naive approach of just marking the method as invalid |
442 | // leads to us emitting more diagnostics than we should have to for this case |
443 | // (1 error here *and* 1 error about there being no matching overload at the |
444 | // call site). It might be possible to avoid that by also checking if there |
445 | // is an empty cast path for the method stored in the context (signalling that |
446 | // we've already diagnosed it) and then just not building the call, but that |
447 | // doesn't really seem any simpler than diagnosing it at the call site... |
448 | auto [It, Inserted] = Context.LambdaCastPaths.try_emplace(Method); |
449 | if (!Inserted) |
450 | return It->second.empty(); |
451 | |
452 | CXXCastPath &Path = It->second; |
453 | CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, |
454 | /*DetectVirtual=*/false); |
455 | if (!IsDerivedFrom(RD->getLocation(), ExplicitObjectParameterType, LambdaType, |
456 | Paths)) { |
457 | Diag(Param->getLocation(), diag::err_invalid_explicit_object_type_in_lambda) |
458 | << ExplicitObjectParameterType; |
459 | return true; |
460 | } |
461 | |
462 | if (Paths.isAmbiguous(BaseType: LambdaType->getCanonicalTypeUnqualified())) { |
463 | std::string PathsDisplay = getAmbiguousPathsDisplayString(Paths); |
464 | Diag(CallLoc, diag::err_explicit_object_lambda_ambiguous_base) |
465 | << LambdaType << PathsDisplay; |
466 | return true; |
467 | } |
468 | |
469 | if (CheckBaseClassAccess(CallLoc, LambdaType, ExplicitObjectParameterType, |
470 | Paths.front(), |
471 | diag::err_explicit_object_lambda_inaccessible_base)) |
472 | return true; |
473 | |
474 | BuildBasePathArray(Paths, BasePath&: Path); |
475 | return false; |
476 | } |
477 | |
478 | void Sema::handleLambdaNumbering( |
479 | CXXRecordDecl *Class, CXXMethodDecl *Method, |
480 | std::optional<CXXRecordDecl::LambdaNumbering> NumberingOverride) { |
481 | if (NumberingOverride) { |
482 | Class->setLambdaNumbering(*NumberingOverride); |
483 | return; |
484 | } |
485 | |
486 | ContextRAII ManglingContext(*this, Class->getDeclContext()); |
487 | |
488 | auto getMangleNumberingContext = |
489 | [this](CXXRecordDecl *Class, |
490 | Decl *ManglingContextDecl) -> MangleNumberingContext * { |
491 | // Get mangle numbering context if there's any extra decl context. |
492 | if (ManglingContextDecl) |
493 | return &Context.getManglingNumberContext( |
494 | ASTContext::NeedExtraManglingDecl, D: ManglingContextDecl); |
495 | // Otherwise, from that lambda's decl context. |
496 | auto DC = Class->getDeclContext(); |
497 | while (auto *CD = dyn_cast<CapturedDecl>(DC)) |
498 | DC = CD->getParent(); |
499 | return &Context.getManglingNumberContext(DC); |
500 | }; |
501 | |
502 | CXXRecordDecl::LambdaNumbering Numbering; |
503 | MangleNumberingContext *MCtx; |
504 | std::tie(args&: MCtx, args&: Numbering.ContextDecl) = |
505 | getCurrentMangleNumberContext(DC: Class->getDeclContext()); |
506 | if (!MCtx && (getLangOpts().CUDA || getLangOpts().SYCLIsDevice || |
507 | getLangOpts().SYCLIsHost)) { |
508 | // Force lambda numbering in CUDA/HIP as we need to name lambdas following |
509 | // ODR. Both device- and host-compilation need to have a consistent naming |
510 | // on kernel functions. As lambdas are potential part of these `__global__` |
511 | // function names, they needs numbering following ODR. |
512 | // Also force for SYCL, since we need this for the |
513 | // __builtin_sycl_unique_stable_name implementation, which depends on lambda |
514 | // mangling. |
515 | MCtx = getMangleNumberingContext(Class, Numbering.ContextDecl); |
516 | assert(MCtx && "Retrieving mangle numbering context failed!"); |
517 | Numbering.HasKnownInternalLinkage = true; |
518 | } |
519 | if (MCtx) { |
520 | Numbering.IndexInContext = MCtx->getNextLambdaIndex(); |
521 | Numbering.ManglingNumber = MCtx->getManglingNumber(CallOperator: Method); |
522 | Numbering.DeviceManglingNumber = MCtx->getDeviceManglingNumber(Method); |
523 | Class->setLambdaNumbering(Numbering); |
524 | |
525 | if (auto *Source = |
526 | dyn_cast_or_null<ExternalSemaSource>(Val: Context.getExternalSource())) |
527 | Source->AssignedLambdaNumbering(Lambda: Class); |
528 | } |
529 | } |
530 | |
531 | static void buildLambdaScopeReturnType(Sema &S, LambdaScopeInfo *LSI, |
532 | CXXMethodDecl *CallOperator, |
533 | bool ExplicitResultType) { |
534 | if (ExplicitResultType) { |
535 | LSI->HasImplicitReturnType = false; |
536 | LSI->ReturnType = CallOperator->getReturnType(); |
537 | if (!LSI->ReturnType->isDependentType() && !LSI->ReturnType->isVoidType()) |
538 | S.RequireCompleteType(CallOperator->getBeginLoc(), LSI->ReturnType, |
539 | diag::err_lambda_incomplete_result); |
540 | } else { |
541 | LSI->HasImplicitReturnType = true; |
542 | } |
543 | } |
544 | |
545 | void Sema::buildLambdaScope(LambdaScopeInfo *LSI, CXXMethodDecl *CallOperator, |
546 | SourceRange IntroducerRange, |
547 | LambdaCaptureDefault CaptureDefault, |
548 | SourceLocation CaptureDefaultLoc, |
549 | bool ExplicitParams, bool Mutable) { |
550 | LSI->CallOperator = CallOperator; |
551 | CXXRecordDecl *LambdaClass = CallOperator->getParent(); |
552 | LSI->Lambda = LambdaClass; |
553 | if (CaptureDefault == LCD_ByCopy) |
554 | LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByval; |
555 | else if (CaptureDefault == LCD_ByRef) |
556 | LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByref; |
557 | LSI->CaptureDefaultLoc = CaptureDefaultLoc; |
558 | LSI->IntroducerRange = IntroducerRange; |
559 | LSI->ExplicitParams = ExplicitParams; |
560 | LSI->Mutable = Mutable; |
561 | } |
562 | |
563 | void Sema::finishLambdaExplicitCaptures(LambdaScopeInfo *LSI) { |
564 | LSI->finishedExplicitCaptures(); |
565 | } |
566 | |
567 | void Sema::ActOnLambdaExplicitTemplateParameterList( |
568 | LambdaIntroducer &Intro, SourceLocation LAngleLoc, |
569 | ArrayRef<NamedDecl *> TParams, SourceLocation RAngleLoc, |
570 | ExprResult RequiresClause) { |
571 | LambdaScopeInfo *LSI = getCurLambda(); |
572 | assert(LSI && "Expected a lambda scope"); |
573 | assert(LSI->NumExplicitTemplateParams == 0 && |
574 | "Already acted on explicit template parameters"); |
575 | assert(LSI->TemplateParams.empty() && |
576 | "Explicit template parameters should come " |
577 | "before invented (auto) ones"); |
578 | assert(!TParams.empty() && |
579 | "No template parameters to act on"); |
580 | LSI->TemplateParams.append(in_start: TParams.begin(), in_end: TParams.end()); |
581 | LSI->NumExplicitTemplateParams = TParams.size(); |
582 | LSI->ExplicitTemplateParamsRange = {LAngleLoc, RAngleLoc}; |
583 | LSI->RequiresClause = RequiresClause; |
584 | } |
585 | |
586 | /// If this expression is an enumerator-like expression of some type |
587 | /// T, return the type T; otherwise, return null. |
588 | /// |
589 | /// Pointer comparisons on the result here should always work because |
590 | /// it's derived from either the parent of an EnumConstantDecl |
591 | /// (i.e. the definition) or the declaration returned by |
592 | /// EnumType::getDecl() (i.e. the definition). |
593 | static EnumDecl *findEnumForBlockReturn(Expr *E) { |
594 | // An expression is an enumerator-like expression of type T if, |
595 | // ignoring parens and parens-like expressions: |
596 | E = E->IgnoreParens(); |
597 | |
598 | // - it is an enumerator whose enum type is T or |
599 | if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Val: E)) { |
600 | if (EnumConstantDecl *D |
601 | = dyn_cast<EnumConstantDecl>(Val: DRE->getDecl())) { |
602 | return cast<EnumDecl>(D->getDeclContext()); |
603 | } |
604 | return nullptr; |
605 | } |
606 | |
607 | // - it is a comma expression whose RHS is an enumerator-like |
608 | // expression of type T or |
609 | if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Val: E)) { |
610 | if (BO->getOpcode() == BO_Comma) |
611 | return findEnumForBlockReturn(E: BO->getRHS()); |
612 | return nullptr; |
613 | } |
614 | |
615 | // - it is a statement-expression whose value expression is an |
616 | // enumerator-like expression of type T or |
617 | if (StmtExpr *SE = dyn_cast<StmtExpr>(Val: E)) { |
618 | if (Expr *last = dyn_cast_or_null<Expr>(Val: SE->getSubStmt()->body_back())) |
619 | return findEnumForBlockReturn(E: last); |
620 | return nullptr; |
621 | } |
622 | |
623 | // - it is a ternary conditional operator (not the GNU ?: |
624 | // extension) whose second and third operands are |
625 | // enumerator-like expressions of type T or |
626 | if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(Val: E)) { |
627 | if (EnumDecl *ED = findEnumForBlockReturn(E: CO->getTrueExpr())) |
628 | if (ED == findEnumForBlockReturn(E: CO->getFalseExpr())) |
629 | return ED; |
630 | return nullptr; |
631 | } |
632 | |
633 | // (implicitly:) |
634 | // - it is an implicit integral conversion applied to an |
635 | // enumerator-like expression of type T or |
636 | if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Val: E)) { |
637 | // We can sometimes see integral conversions in valid |
638 | // enumerator-like expressions. |
639 | if (ICE->getCastKind() == CK_IntegralCast) |
640 | return findEnumForBlockReturn(ICE->getSubExpr()); |
641 | |
642 | // Otherwise, just rely on the type. |
643 | } |
644 | |
645 | // - it is an expression of that formal enum type. |
646 | if (const EnumType *ET = E->getType()->getAs<EnumType>()) { |
647 | return ET->getDecl(); |
648 | } |
649 | |
650 | // Otherwise, nope. |
651 | return nullptr; |
652 | } |
653 | |
654 | /// Attempt to find a type T for which the returned expression of the |
655 | /// given statement is an enumerator-like expression of that type. |
656 | static EnumDecl *findEnumForBlockReturn(ReturnStmt *ret) { |
657 | if (Expr *retValue = ret->getRetValue()) |
658 | return findEnumForBlockReturn(E: retValue); |
659 | return nullptr; |
660 | } |
661 | |
662 | /// Attempt to find a common type T for which all of the returned |
663 | /// expressions in a block are enumerator-like expressions of that |
664 | /// type. |
665 | static EnumDecl *findCommonEnumForBlockReturns(ArrayRef<ReturnStmt*> returns) { |
666 | ArrayRef<ReturnStmt*>::iterator i = returns.begin(), e = returns.end(); |
667 | |
668 | // Try to find one for the first return. |
669 | EnumDecl *ED = findEnumForBlockReturn(ret: *i); |
670 | if (!ED) return nullptr; |
671 | |
672 | // Check that the rest of the returns have the same enum. |
673 | for (++i; i != e; ++i) { |
674 | if (findEnumForBlockReturn(ret: *i) != ED) |
675 | return nullptr; |
676 | } |
677 | |
678 | // Never infer an anonymous enum type. |
679 | if (!ED->hasNameForLinkage()) return nullptr; |
680 | |
681 | return ED; |
682 | } |
683 | |
684 | /// Adjust the given return statements so that they formally return |
685 | /// the given type. It should require, at most, an IntegralCast. |
686 | static void adjustBlockReturnsToEnum(Sema &S, ArrayRef<ReturnStmt*> returns, |
687 | QualType returnType) { |
688 | for (ArrayRef<ReturnStmt*>::iterator |
689 | i = returns.begin(), e = returns.end(); i != e; ++i) { |
690 | ReturnStmt *ret = *i; |
691 | Expr *retValue = ret->getRetValue(); |
692 | if (S.Context.hasSameType(T1: retValue->getType(), T2: returnType)) |
693 | continue; |
694 | |
695 | // Right now we only support integral fixup casts. |
696 | assert(returnType->isIntegralOrUnscopedEnumerationType()); |
697 | assert(retValue->getType()->isIntegralOrUnscopedEnumerationType()); |
698 | |
699 | ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(Val: retValue); |
700 | |
701 | Expr *E = (cleanups ? cleanups->getSubExpr() : retValue); |
702 | E = ImplicitCastExpr::Create(Context: S.Context, T: returnType, Kind: CK_IntegralCast, Operand: E, |
703 | /*base path*/ BasePath: nullptr, Cat: VK_PRValue, |
704 | FPO: FPOptionsOverride()); |
705 | if (cleanups) { |
706 | cleanups->setSubExpr(E); |
707 | } else { |
708 | ret->setRetValue(E); |
709 | } |
710 | } |
711 | } |
712 | |
713 | void Sema::deduceClosureReturnType(CapturingScopeInfo &CSI) { |
714 | assert(CSI.HasImplicitReturnType); |
715 | // If it was ever a placeholder, it had to been deduced to DependentTy. |
716 | assert(CSI.ReturnType.isNull() || !CSI.ReturnType->isUndeducedType()); |
717 | assert((!isa<LambdaScopeInfo>(CSI) || !getLangOpts().CPlusPlus14) && |
718 | "lambda expressions use auto deduction in C++14 onwards"); |
719 | |
720 | // C++ core issue 975: |
721 | // If a lambda-expression does not include a trailing-return-type, |
722 | // it is as if the trailing-return-type denotes the following type: |
723 | // - if there are no return statements in the compound-statement, |
724 | // or all return statements return either an expression of type |
725 | // void or no expression or braced-init-list, the type void; |
726 | // - otherwise, if all return statements return an expression |
727 | // and the types of the returned expressions after |
728 | // lvalue-to-rvalue conversion (4.1 [conv.lval]), |
729 | // array-to-pointer conversion (4.2 [conv.array]), and |
730 | // function-to-pointer conversion (4.3 [conv.func]) are the |
731 | // same, that common type; |
732 | // - otherwise, the program is ill-formed. |
733 | // |
734 | // C++ core issue 1048 additionally removes top-level cv-qualifiers |
735 | // from the types of returned expressions to match the C++14 auto |
736 | // deduction rules. |
737 | // |
738 | // In addition, in blocks in non-C++ modes, if all of the return |
739 | // statements are enumerator-like expressions of some type T, where |
740 | // T has a name for linkage, then we infer the return type of the |
741 | // block to be that type. |
742 | |
743 | // First case: no return statements, implicit void return type. |
744 | ASTContext &Ctx = getASTContext(); |
745 | if (CSI.Returns.empty()) { |
746 | // It's possible there were simply no /valid/ return statements. |
747 | // In this case, the first one we found may have at least given us a type. |
748 | if (CSI.ReturnType.isNull()) |
749 | CSI.ReturnType = Ctx.VoidTy; |
750 | return; |
751 | } |
752 | |
753 | // Second case: at least one return statement has dependent type. |
754 | // Delay type checking until instantiation. |
755 | assert(!CSI.ReturnType.isNull() && "We should have a tentative return type."); |
756 | if (CSI.ReturnType->isDependentType()) |
757 | return; |
758 | |
759 | // Try to apply the enum-fuzz rule. |
760 | if (!getLangOpts().CPlusPlus) { |
761 | assert(isa<BlockScopeInfo>(CSI)); |
762 | const EnumDecl *ED = findCommonEnumForBlockReturns(returns: CSI.Returns); |
763 | if (ED) { |
764 | CSI.ReturnType = Context.getTypeDeclType(ED); |
765 | adjustBlockReturnsToEnum(*this, CSI.Returns, CSI.ReturnType); |
766 | return; |
767 | } |
768 | } |
769 | |
770 | // Third case: only one return statement. Don't bother doing extra work! |
771 | if (CSI.Returns.size() == 1) |
772 | return; |
773 | |
774 | // General case: many return statements. |
775 | // Check that they all have compatible return types. |
776 | |
777 | // We require the return types to strictly match here. |
778 | // Note that we've already done the required promotions as part of |
779 | // processing the return statement. |
780 | for (const ReturnStmt *RS : CSI.Returns) { |
781 | const Expr *RetE = RS->getRetValue(); |
782 | |
783 | QualType ReturnType = |
784 | (RetE ? RetE->getType() : Context.VoidTy).getUnqualifiedType(); |
785 | if (Context.getCanonicalFunctionResultType(ResultType: ReturnType) == |
786 | Context.getCanonicalFunctionResultType(ResultType: CSI.ReturnType)) { |
787 | // Use the return type with the strictest possible nullability annotation. |
788 | auto RetTyNullability = ReturnType->getNullability(); |
789 | auto BlockNullability = CSI.ReturnType->getNullability(); |
790 | if (BlockNullability && |
791 | (!RetTyNullability || |
792 | hasWeakerNullability(*RetTyNullability, *BlockNullability))) |
793 | CSI.ReturnType = ReturnType; |
794 | continue; |
795 | } |
796 | |
797 | // FIXME: This is a poor diagnostic for ReturnStmts without expressions. |
798 | // TODO: It's possible that the *first* return is the divergent one. |
799 | Diag(RS->getBeginLoc(), |
800 | diag::err_typecheck_missing_return_type_incompatible) |
801 | << ReturnType << CSI.ReturnType << isa<LambdaScopeInfo>(CSI); |
802 | // Continue iterating so that we keep emitting diagnostics. |
803 | } |
804 | } |
805 | |
806 | QualType Sema::buildLambdaInitCaptureInitialization( |
807 | SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc, |
808 | UnsignedOrNone NumExpansions, IdentifierInfo *Id, bool IsDirectInit, |
809 | Expr *&Init) { |
810 | // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to |
811 | // deduce against. |
812 | QualType DeductType = Context.getAutoDeductType(); |
813 | TypeLocBuilder TLB; |
814 | AutoTypeLoc TL = TLB.push<AutoTypeLoc>(T: DeductType); |
815 | TL.setNameLoc(Loc); |
816 | if (ByRef) { |
817 | DeductType = BuildReferenceType(T: DeductType, LValueRef: true, Loc, Entity: Id); |
818 | assert(!DeductType.isNull() && "can't build reference to auto"); |
819 | TLB.push<ReferenceTypeLoc>(T: DeductType).setSigilLoc(Loc); |
820 | } |
821 | if (EllipsisLoc.isValid()) { |
822 | if (Init->containsUnexpandedParameterPack()) { |
823 | Diag(EllipsisLoc, getLangOpts().CPlusPlus20 |
824 | ? diag::warn_cxx17_compat_init_capture_pack |
825 | : diag::ext_init_capture_pack); |
826 | DeductType = Context.getPackExpansionType(Pattern: DeductType, NumExpansions, |
827 | /*ExpectPackInType=*/false); |
828 | TLB.push<PackExpansionTypeLoc>(T: DeductType).setEllipsisLoc(EllipsisLoc); |
829 | } else { |
830 | // Just ignore the ellipsis for now and form a non-pack variable. We'll |
831 | // diagnose this later when we try to capture it. |
832 | } |
833 | } |
834 | TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, T: DeductType); |
835 | |
836 | // Deduce the type of the init capture. |
837 | QualType DeducedType = deduceVarTypeFromInitializer( |
838 | /*VarDecl*/VDecl: nullptr, Name: DeclarationName(Id), Type: DeductType, TSI, |
839 | Range: SourceRange(Loc, Loc), DirectInit: IsDirectInit, Init); |
840 | if (DeducedType.isNull()) |
841 | return QualType(); |
842 | |
843 | // Are we a non-list direct initialization? |
844 | ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Val: Init); |
845 | |
846 | // Perform initialization analysis and ensure any implicit conversions |
847 | // (such as lvalue-to-rvalue) are enforced. |
848 | InitializedEntity Entity = |
849 | InitializedEntity::InitializeLambdaCapture(VarID: Id, FieldType: DeducedType, Loc); |
850 | InitializationKind Kind = |
851 | IsDirectInit |
852 | ? (CXXDirectInit ? InitializationKind::CreateDirect( |
853 | InitLoc: Loc, LParenLoc: Init->getBeginLoc(), RParenLoc: Init->getEndLoc()) |
854 | : InitializationKind::CreateDirectList(InitLoc: Loc)) |
855 | : InitializationKind::CreateCopy(InitLoc: Loc, EqualLoc: Init->getBeginLoc()); |
856 | |
857 | MultiExprArg Args = Init; |
858 | if (CXXDirectInit) |
859 | Args = |
860 | MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs()); |
861 | QualType DclT; |
862 | InitializationSequence InitSeq(*this, Entity, Kind, Args); |
863 | ExprResult Result = InitSeq.Perform(S&: *this, Entity, Kind, Args, ResultType: &DclT); |
864 | |
865 | if (Result.isInvalid()) |
866 | return QualType(); |
867 | |
868 | Init = Result.getAs<Expr>(); |
869 | return DeducedType; |
870 | } |
871 | |
872 | VarDecl *Sema::createLambdaInitCaptureVarDecl( |
873 | SourceLocation Loc, QualType InitCaptureType, SourceLocation EllipsisLoc, |
874 | IdentifierInfo *Id, unsigned InitStyle, Expr *Init, DeclContext *DeclCtx) { |
875 | // FIXME: Retain the TypeSourceInfo from buildLambdaInitCaptureInitialization |
876 | // rather than reconstructing it here. |
877 | TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(T: InitCaptureType, Loc); |
878 | if (auto PETL = TSI->getTypeLoc().getAs<PackExpansionTypeLoc>()) |
879 | PETL.setEllipsisLoc(EllipsisLoc); |
880 | |
881 | // Create a dummy variable representing the init-capture. This is not actually |
882 | // used as a variable, and only exists as a way to name and refer to the |
883 | // init-capture. |
884 | // FIXME: Pass in separate source locations for '&' and identifier. |
885 | VarDecl *NewVD = VarDecl::Create(C&: Context, DC: DeclCtx, StartLoc: Loc, IdLoc: Loc, Id, |
886 | T: InitCaptureType, TInfo: TSI, S: SC_Auto); |
887 | NewVD->setInitCapture(true); |
888 | NewVD->setReferenced(true); |
889 | // FIXME: Pass in a VarDecl::InitializationStyle. |
890 | NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle)); |
891 | NewVD->markUsed(Context); |
892 | NewVD->setInit(Init); |
893 | if (NewVD->isParameterPack()) |
894 | getCurLambda()->LocalPacks.push_back(NewVD); |
895 | return NewVD; |
896 | } |
897 | |
898 | void Sema::addInitCapture(LambdaScopeInfo *LSI, VarDecl *Var, bool ByRef) { |
899 | assert(Var->isInitCapture() && "init capture flag should be set"); |
900 | LSI->addCapture(Var, /*isBlock=*/false, isByref: ByRef, |
901 | /*isNested=*/false, Loc: Var->getLocation(), EllipsisLoc: SourceLocation(), |
902 | CaptureType: Var->getType(), /*Invalid=*/false); |
903 | } |
904 | |
905 | // Unlike getCurLambda, getCurrentLambdaScopeUnsafe doesn't |
906 | // check that the current lambda is in a consistent or fully constructed state. |
907 | static LambdaScopeInfo *getCurrentLambdaScopeUnsafe(Sema &S) { |
908 | assert(!S.FunctionScopes.empty()); |
909 | return cast<LambdaScopeInfo>(Val: S.FunctionScopes[S.FunctionScopes.size() - 1]); |
910 | } |
911 | |
912 | static TypeSourceInfo * |
913 | getDummyLambdaType(Sema &S, SourceLocation Loc = SourceLocation()) { |
914 | // C++11 [expr.prim.lambda]p4: |
915 | // If a lambda-expression does not include a lambda-declarator, it is as |
916 | // if the lambda-declarator were (). |
917 | FunctionProtoType::ExtProtoInfo EPI(S.Context.getDefaultCallingConvention( |
918 | /*IsVariadic=*/false, /*IsCXXMethod=*/true)); |
919 | EPI.HasTrailingReturn = true; |
920 | EPI.TypeQuals.addConst(); |
921 | LangAS AS = S.getDefaultCXXMethodAddrSpace(); |
922 | if (AS != LangAS::Default) |
923 | EPI.TypeQuals.addAddressSpace(space: AS); |
924 | |
925 | // C++1y [expr.prim.lambda]: |
926 | // The lambda return type is 'auto', which is replaced by the |
927 | // trailing-return type if provided and/or deduced from 'return' |
928 | // statements |
929 | // We don't do this before C++1y, because we don't support deduced return |
930 | // types there. |
931 | QualType DefaultTypeForNoTrailingReturn = S.getLangOpts().CPlusPlus14 |
932 | ? S.Context.getAutoDeductType() |
933 | : S.Context.DependentTy; |
934 | QualType MethodTy = |
935 | S.Context.getFunctionType(ResultTy: DefaultTypeForNoTrailingReturn, Args: {}, EPI); |
936 | return S.Context.getTrivialTypeSourceInfo(T: MethodTy, Loc); |
937 | } |
938 | |
939 | static TypeSourceInfo *getLambdaType(Sema &S, LambdaIntroducer &Intro, |
940 | Declarator &ParamInfo, Scope *CurScope, |
941 | SourceLocation Loc, |
942 | bool &ExplicitResultType) { |
943 | |
944 | ExplicitResultType = false; |
945 | |
946 | assert( |
947 | (ParamInfo.getDeclSpec().getStorageClassSpec() == |
948 | DeclSpec::SCS_unspecified || |
949 | ParamInfo.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static) && |
950 | "Unexpected storage specifier"); |
951 | bool IsLambdaStatic = |
952 | ParamInfo.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static; |
953 | |
954 | TypeSourceInfo *MethodTyInfo; |
955 | |
956 | if (ParamInfo.getNumTypeObjects() == 0) { |
957 | MethodTyInfo = getDummyLambdaType(S, Loc); |
958 | } else { |
959 | // Check explicit parameters |
960 | S.CheckExplicitObjectLambda(D&: ParamInfo); |
961 | |
962 | DeclaratorChunk::FunctionTypeInfo &FTI = ParamInfo.getFunctionTypeInfo(); |
963 | |
964 | bool HasExplicitObjectParameter = |
965 | ParamInfo.isExplicitObjectMemberFunction(); |
966 | |
967 | ExplicitResultType = FTI.hasTrailingReturnType(); |
968 | if (!FTI.hasMutableQualifier() && !IsLambdaStatic && |
969 | !HasExplicitObjectParameter) |
970 | FTI.getOrCreateMethodQualifiers().SetTypeQual(T: DeclSpec::TQ_const, Loc); |
971 | |
972 | if (ExplicitResultType && S.getLangOpts().HLSL) { |
973 | QualType RetTy = FTI.getTrailingReturnType().get(); |
974 | if (!RetTy.isNull()) { |
975 | // HLSL does not support specifying an address space on a lambda return |
976 | // type. |
977 | LangAS AddressSpace = RetTy.getAddressSpace(); |
978 | if (AddressSpace != LangAS::Default) |
979 | S.Diag(FTI.getTrailingReturnTypeLoc(), |
980 | diag::err_return_value_with_address_space); |
981 | } |
982 | } |
983 | |
984 | MethodTyInfo = S.GetTypeForDeclarator(D&: ParamInfo); |
985 | assert(MethodTyInfo && "no type from lambda-declarator"); |
986 | |
987 | // Check for unexpanded parameter packs in the method type. |
988 | if (MethodTyInfo->getType()->containsUnexpandedParameterPack()) |
989 | S.DiagnoseUnexpandedParameterPack(Loc: Intro.Range.getBegin(), T: MethodTyInfo, |
990 | UPPC: S.UPPC_DeclarationType); |
991 | } |
992 | return MethodTyInfo; |
993 | } |
994 | |
995 | CXXMethodDecl *Sema::CreateLambdaCallOperator(SourceRange IntroducerRange, |
996 | CXXRecordDecl *Class) { |
997 | |
998 | // C++20 [expr.prim.lambda.closure]p3: |
999 | // The closure type for a lambda-expression has a public inline function |
1000 | // call operator (for a non-generic lambda) or function call operator |
1001 | // template (for a generic lambda) whose parameters and return type are |
1002 | // described by the lambda-expression's parameter-declaration-clause |
1003 | // and trailing-return-type respectively. |
1004 | DeclarationName MethodName = |
1005 | Context.DeclarationNames.getCXXOperatorName(Op: OO_Call); |
1006 | DeclarationNameLoc MethodNameLoc = |
1007 | DeclarationNameLoc::makeCXXOperatorNameLoc(Range: IntroducerRange.getBegin()); |
1008 | CXXMethodDecl *Method = CXXMethodDecl::Create( |
1009 | C&: Context, RD: Class, StartLoc: SourceLocation(), |
1010 | NameInfo: DeclarationNameInfo(MethodName, IntroducerRange.getBegin(), |
1011 | MethodNameLoc), |
1012 | T: QualType(), /*Tinfo=*/TInfo: nullptr, SC: SC_None, |
1013 | UsesFPIntrin: getCurFPFeatures().isFPConstrained(), |
1014 | /*isInline=*/true, ConstexprKind: ConstexprSpecKind::Unspecified, EndLocation: SourceLocation(), |
1015 | /*TrailingRequiresClause=*/{}); |
1016 | Method->setAccess(AS_public); |
1017 | return Method; |
1018 | } |
1019 | |
1020 | void Sema::AddTemplateParametersToLambdaCallOperator( |
1021 | CXXMethodDecl *CallOperator, CXXRecordDecl *Class, |
1022 | TemplateParameterList *TemplateParams) { |
1023 | assert(TemplateParams && "no template parameters"); |
1024 | FunctionTemplateDecl *TemplateMethod = FunctionTemplateDecl::Create( |
1025 | C&: Context, DC: Class, L: CallOperator->getLocation(), Name: CallOperator->getDeclName(), |
1026 | Params: TemplateParams, Decl: CallOperator); |
1027 | TemplateMethod->setAccess(AS_public); |
1028 | CallOperator->setDescribedFunctionTemplate(TemplateMethod); |
1029 | } |
1030 | |
1031 | void Sema::CompleteLambdaCallOperator( |
1032 | CXXMethodDecl *Method, SourceLocation LambdaLoc, |
1033 | SourceLocation CallOperatorLoc, |
1034 | const AssociatedConstraint &TrailingRequiresClause, |
1035 | TypeSourceInfo *MethodTyInfo, ConstexprSpecKind ConstexprKind, |
1036 | StorageClass SC, ArrayRef<ParmVarDecl *> Params, |
1037 | bool HasExplicitResultType) { |
1038 | |
1039 | LambdaScopeInfo *LSI = getCurrentLambdaScopeUnsafe(S&: *this); |
1040 | |
1041 | if (TrailingRequiresClause) |
1042 | Method->setTrailingRequiresClause(TrailingRequiresClause); |
1043 | |
1044 | TemplateParameterList *TemplateParams = |
1045 | getGenericLambdaTemplateParameterList(LSI, SemaRef&: *this); |
1046 | |
1047 | DeclContext *DC = Method->getLexicalDeclContext(); |
1048 | // DeclContext::addDecl() assumes that the DeclContext we're adding to is the |
1049 | // lexical context of the Method. Do so. |
1050 | Method->setLexicalDeclContext(LSI->Lambda); |
1051 | if (TemplateParams) { |
1052 | FunctionTemplateDecl *TemplateMethod = |
1053 | Method->getDescribedFunctionTemplate(); |
1054 | assert(TemplateMethod && |
1055 | "AddTemplateParametersToLambdaCallOperator should have been called"); |
1056 | |
1057 | LSI->Lambda->addDecl(TemplateMethod); |
1058 | TemplateMethod->setLexicalDeclContext(DC); |
1059 | } else { |
1060 | LSI->Lambda->addDecl(Method); |
1061 | } |
1062 | LSI->Lambda->setLambdaIsGeneric(TemplateParams); |
1063 | LSI->Lambda->setLambdaTypeInfo(MethodTyInfo); |
1064 | |
1065 | Method->setLexicalDeclContext(DC); |
1066 | Method->setLocation(LambdaLoc); |
1067 | Method->setInnerLocStart(CallOperatorLoc); |
1068 | Method->setTypeSourceInfo(MethodTyInfo); |
1069 | Method->setType(buildTypeForLambdaCallOperator(S&: *this, Class: LSI->Lambda, |
1070 | TemplateParams, MethodTypeInfo: MethodTyInfo)); |
1071 | Method->setConstexprKind(ConstexprKind); |
1072 | Method->setStorageClass(SC); |
1073 | if (!Params.empty()) { |
1074 | CheckParmsForFunctionDef(Parameters: Params, /*CheckParameterNames=*/false); |
1075 | Method->setParams(Params); |
1076 | for (auto P : Method->parameters()) { |
1077 | assert(P && "null in a parameter list"); |
1078 | P->setOwningFunction(Method); |
1079 | } |
1080 | } |
1081 | |
1082 | buildLambdaScopeReturnType(S&: *this, LSI, CallOperator: Method, ExplicitResultType: HasExplicitResultType); |
1083 | } |
1084 | |
1085 | void Sema::ActOnLambdaExpressionAfterIntroducer(LambdaIntroducer &Intro, |
1086 | Scope *CurrentScope) { |
1087 | |
1088 | LambdaScopeInfo *LSI = getCurLambda(); |
1089 | assert(LSI && "LambdaScopeInfo should be on stack!"); |
1090 | |
1091 | if (Intro.Default == LCD_ByCopy) |
1092 | LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByval; |
1093 | else if (Intro.Default == LCD_ByRef) |
1094 | LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByref; |
1095 | LSI->CaptureDefaultLoc = Intro.DefaultLoc; |
1096 | LSI->IntroducerRange = Intro.Range; |
1097 | LSI->AfterParameterList = false; |
1098 | |
1099 | assert(LSI->NumExplicitTemplateParams == 0); |
1100 | |
1101 | // Determine if we're within a context where we know that the lambda will |
1102 | // be dependent, because there are template parameters in scope. |
1103 | CXXRecordDecl::LambdaDependencyKind LambdaDependencyKind = |
1104 | CXXRecordDecl::LDK_Unknown; |
1105 | if (CurScope->getTemplateParamParent() != nullptr) { |
1106 | LambdaDependencyKind = CXXRecordDecl::LDK_AlwaysDependent; |
1107 | } else if (Scope *P = CurScope->getParent()) { |
1108 | // Given a lambda defined inside a requires expression, |
1109 | // |
1110 | // struct S { |
1111 | // S(auto var) requires requires { [&] -> decltype(var) { }; } |
1112 | // {} |
1113 | // }; |
1114 | // |
1115 | // The parameter var is not injected into the function Decl at the point of |
1116 | // parsing lambda. In such scenarios, perceiving it as dependent could |
1117 | // result in the constraint being evaluated, which matches what GCC does. |
1118 | while (P->getEntity() && P->getEntity()->isRequiresExprBody()) |
1119 | P = P->getParent(); |
1120 | if (P->isFunctionDeclarationScope() && |
1121 | llvm::any_of(Range: P->decls(), P: [](Decl *D) { |
1122 | return isa<ParmVarDecl>(D) && |
1123 | cast<ParmVarDecl>(D)->getType()->isTemplateTypeParmType(); |
1124 | })) |
1125 | LambdaDependencyKind = CXXRecordDecl::LDK_AlwaysDependent; |
1126 | } |
1127 | |
1128 | CXXRecordDecl *Class = createLambdaClosureType( |
1129 | IntroducerRange: Intro.Range, /*Info=*/nullptr, LambdaDependencyKind, CaptureDefault: Intro.Default); |
1130 | LSI->Lambda = Class; |
1131 | |
1132 | CXXMethodDecl *Method = CreateLambdaCallOperator(IntroducerRange: Intro.Range, Class); |
1133 | LSI->CallOperator = Method; |
1134 | // Temporarily set the lexical declaration context to the current |
1135 | // context, so that the Scope stack matches the lexical nesting. |
1136 | Method->setLexicalDeclContext(CurContext); |
1137 | |
1138 | PushDeclContext(CurScope, Method); |
1139 | |
1140 | bool ContainsUnexpandedParameterPack = false; |
1141 | |
1142 | // Distinct capture names, for diagnostics. |
1143 | llvm::DenseMap<IdentifierInfo *, ValueDecl *> CaptureNames; |
1144 | |
1145 | // Handle explicit captures. |
1146 | SourceLocation PrevCaptureLoc = |
1147 | Intro.Default == LCD_None ? Intro.Range.getBegin() : Intro.DefaultLoc; |
1148 | for (auto C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E; |
1149 | PrevCaptureLoc = C->Loc, ++C) { |
1150 | if (C->Kind == LCK_This || C->Kind == LCK_StarThis) { |
1151 | if (C->Kind == LCK_StarThis) |
1152 | Diag(C->Loc, !getLangOpts().CPlusPlus17 |
1153 | ? diag::ext_star_this_lambda_capture_cxx17 |
1154 | : diag::warn_cxx14_compat_star_this_lambda_capture); |
1155 | |
1156 | // C++11 [expr.prim.lambda]p8: |
1157 | // An identifier or this shall not appear more than once in a |
1158 | // lambda-capture. |
1159 | if (LSI->isCXXThisCaptured()) { |
1160 | Diag(C->Loc, diag::err_capture_more_than_once) |
1161 | << "'this'"<< SourceRange(LSI->getCXXThisCapture().getLocation()) |
1162 | << FixItHint::CreateRemoval( |
1163 | SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc)); |
1164 | continue; |
1165 | } |
1166 | |
1167 | // C++20 [expr.prim.lambda]p8: |
1168 | // If a lambda-capture includes a capture-default that is =, |
1169 | // each simple-capture of that lambda-capture shall be of the form |
1170 | // "&identifier", "this", or "* this". [ Note: The form [&,this] is |
1171 | // redundant but accepted for compatibility with ISO C++14. --end note ] |
1172 | if (Intro.Default == LCD_ByCopy && C->Kind != LCK_StarThis) |
1173 | Diag(C->Loc, !getLangOpts().CPlusPlus20 |
1174 | ? diag::ext_equals_this_lambda_capture_cxx20 |
1175 | : diag::warn_cxx17_compat_equals_this_lambda_capture); |
1176 | |
1177 | // C++11 [expr.prim.lambda]p12: |
1178 | // If this is captured by a local lambda expression, its nearest |
1179 | // enclosing function shall be a non-static member function. |
1180 | QualType ThisCaptureType = getCurrentThisType(); |
1181 | if (ThisCaptureType.isNull()) { |
1182 | Diag(C->Loc, diag::err_this_capture) << true; |
1183 | continue; |
1184 | } |
1185 | |
1186 | CheckCXXThisCapture(Loc: C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true, |
1187 | /*FunctionScopeIndexToStopAtPtr*/ FunctionScopeIndexToStopAt: nullptr, |
1188 | ByCopy: C->Kind == LCK_StarThis); |
1189 | if (!LSI->Captures.empty()) |
1190 | LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange; |
1191 | continue; |
1192 | } |
1193 | |
1194 | assert(C->Id && "missing identifier for capture"); |
1195 | |
1196 | if (C->Init.isInvalid()) |
1197 | continue; |
1198 | |
1199 | ValueDecl *Var = nullptr; |
1200 | if (C->Init.isUsable()) { |
1201 | Diag(C->Loc, getLangOpts().CPlusPlus14 |
1202 | ? diag::warn_cxx11_compat_init_capture |
1203 | : diag::ext_init_capture); |
1204 | |
1205 | // If the initializer expression is usable, but the InitCaptureType |
1206 | // is not, then an error has occurred - so ignore the capture for now. |
1207 | // for e.g., [n{0}] { }; <-- if no <initializer_list> is included. |
1208 | // FIXME: we should create the init capture variable and mark it invalid |
1209 | // in this case. |
1210 | if (C->InitCaptureType.get().isNull()) |
1211 | continue; |
1212 | |
1213 | if (C->Init.get()->containsUnexpandedParameterPack() && |
1214 | !C->InitCaptureType.get()->getAs<PackExpansionType>()) |
1215 | DiagnoseUnexpandedParameterPack(E: C->Init.get(), UPPC: UPPC_Initializer); |
1216 | |
1217 | unsigned InitStyle; |
1218 | switch (C->InitKind) { |
1219 | case LambdaCaptureInitKind::NoInit: |
1220 | llvm_unreachable("not an init-capture?"); |
1221 | case LambdaCaptureInitKind::CopyInit: |
1222 | InitStyle = VarDecl::CInit; |
1223 | break; |
1224 | case LambdaCaptureInitKind::DirectInit: |
1225 | InitStyle = VarDecl::CallInit; |
1226 | break; |
1227 | case LambdaCaptureInitKind::ListInit: |
1228 | InitStyle = VarDecl::ListInit; |
1229 | break; |
1230 | } |
1231 | Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(), |
1232 | C->EllipsisLoc, C->Id, InitStyle, |
1233 | C->Init.get(), Method); |
1234 | assert(Var && "createLambdaInitCaptureVarDecl returned a null VarDecl?"); |
1235 | if (auto *V = dyn_cast<VarDecl>(Val: Var)) |
1236 | CheckShadow(S: CurrentScope, D: V); |
1237 | PushOnScopeChains(Var, CurrentScope, false); |
1238 | } else { |
1239 | assert(C->InitKind == LambdaCaptureInitKind::NoInit && |
1240 | "init capture has valid but null init?"); |
1241 | |
1242 | // C++11 [expr.prim.lambda]p8: |
1243 | // If a lambda-capture includes a capture-default that is &, the |
1244 | // identifiers in the lambda-capture shall not be preceded by &. |
1245 | // If a lambda-capture includes a capture-default that is =, [...] |
1246 | // each identifier it contains shall be preceded by &. |
1247 | if (C->Kind == LCK_ByRef && Intro.Default == LCD_ByRef) { |
1248 | Diag(C->Loc, diag::err_reference_capture_with_reference_default) |
1249 | << FixItHint::CreateRemoval( |
1250 | SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc)); |
1251 | continue; |
1252 | } else if (C->Kind == LCK_ByCopy && Intro.Default == LCD_ByCopy) { |
1253 | Diag(C->Loc, diag::err_copy_capture_with_copy_default) |
1254 | << FixItHint::CreateRemoval( |
1255 | SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc)); |
1256 | continue; |
1257 | } |
1258 | |
1259 | // C++11 [expr.prim.lambda]p10: |
1260 | // The identifiers in a capture-list are looked up using the usual |
1261 | // rules for unqualified name lookup (3.4.1) |
1262 | DeclarationNameInfo Name(C->Id, C->Loc); |
1263 | LookupResult R(*this, Name, LookupOrdinaryName); |
1264 | LookupName(R, S: CurScope); |
1265 | if (R.isAmbiguous()) |
1266 | continue; |
1267 | if (R.empty()) { |
1268 | // FIXME: Disable corrections that would add qualification? |
1269 | CXXScopeSpec ScopeSpec; |
1270 | DeclFilterCCC<VarDecl> Validator{}; |
1271 | if (DiagnoseEmptyLookup(S: CurScope, SS&: ScopeSpec, R, CCC&: Validator)) |
1272 | continue; |
1273 | } |
1274 | |
1275 | if (auto *BD = R.getAsSingle<BindingDecl>()) |
1276 | Var = BD; |
1277 | else if (R.getAsSingle<FieldDecl>()) { |
1278 | Diag(C->Loc, diag::err_capture_class_member_does_not_name_variable) |
1279 | << C->Id; |
1280 | continue; |
1281 | } else |
1282 | Var = R.getAsSingle<VarDecl>(); |
1283 | if (Var && DiagnoseUseOfDecl(Var, C->Loc)) |
1284 | continue; |
1285 | } |
1286 | |
1287 | // C++11 [expr.prim.lambda]p10: |
1288 | // [...] each such lookup shall find a variable with automatic storage |
1289 | // duration declared in the reaching scope of the local lambda expression. |
1290 | // Note that the 'reaching scope' check happens in tryCaptureVariable(). |
1291 | if (!Var) { |
1292 | Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id; |
1293 | continue; |
1294 | } |
1295 | |
1296 | // C++11 [expr.prim.lambda]p8: |
1297 | // An identifier or this shall not appear more than once in a |
1298 | // lambda-capture. |
1299 | if (auto [It, Inserted] = CaptureNames.insert(KV: std::pair{C->Id, Var}); |
1300 | !Inserted) { |
1301 | if (C->InitKind == LambdaCaptureInitKind::NoInit && |
1302 | !Var->isInitCapture()) { |
1303 | Diag(C->Loc, diag::err_capture_more_than_once) |
1304 | << C->Id << It->second->getBeginLoc() |
1305 | << FixItHint::CreateRemoval( |
1306 | SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc)); |
1307 | Var->setInvalidDecl(); |
1308 | } else if (Var && Var->isPlaceholderVar(getLangOpts())) { |
1309 | DiagPlaceholderVariableDefinition(Loc: C->Loc); |
1310 | } else { |
1311 | // Previous capture captured something different (one or both was |
1312 | // an init-capture): no fixit. |
1313 | Diag(C->Loc, diag::err_capture_more_than_once) << C->Id; |
1314 | continue; |
1315 | } |
1316 | } |
1317 | |
1318 | // Ignore invalid decls; they'll just confuse the code later. |
1319 | if (Var->isInvalidDecl()) |
1320 | continue; |
1321 | |
1322 | VarDecl *Underlying = Var->getPotentiallyDecomposedVarDecl(); |
1323 | |
1324 | if (!Underlying->hasLocalStorage()) { |
1325 | Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id; |
1326 | Diag(Var->getLocation(), diag::note_previous_decl) << C->Id; |
1327 | continue; |
1328 | } |
1329 | |
1330 | // C++11 [expr.prim.lambda]p23: |
1331 | // A capture followed by an ellipsis is a pack expansion (14.5.3). |
1332 | SourceLocation EllipsisLoc; |
1333 | if (C->EllipsisLoc.isValid()) { |
1334 | if (Var->isParameterPack()) { |
1335 | EllipsisLoc = C->EllipsisLoc; |
1336 | } else { |
1337 | Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) |
1338 | << (C->Init.isUsable() ? C->Init.get()->getSourceRange() |
1339 | : SourceRange(C->Loc)); |
1340 | |
1341 | // Just ignore the ellipsis. |
1342 | } |
1343 | } else if (Var->isParameterPack()) { |
1344 | ContainsUnexpandedParameterPack = true; |
1345 | } |
1346 | |
1347 | if (C->Init.isUsable()) { |
1348 | addInitCapture(LSI, Var: cast<VarDecl>(Val: Var), ByRef: C->Kind == LCK_ByRef); |
1349 | } else { |
1350 | TryCaptureKind Kind = C->Kind == LCK_ByRef |
1351 | ? TryCaptureKind::ExplicitByRef |
1352 | : TryCaptureKind::ExplicitByVal; |
1353 | tryCaptureVariable(Var, Loc: C->Loc, Kind, EllipsisLoc); |
1354 | } |
1355 | if (!LSI->Captures.empty()) |
1356 | LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange; |
1357 | } |
1358 | finishLambdaExplicitCaptures(LSI); |
1359 | LSI->ContainsUnexpandedParameterPack |= ContainsUnexpandedParameterPack; |
1360 | PopDeclContext(); |
1361 | } |
1362 | |
1363 | void Sema::ActOnLambdaClosureQualifiers(LambdaIntroducer &Intro, |
1364 | SourceLocation MutableLoc) { |
1365 | |
1366 | LambdaScopeInfo *LSI = getCurrentLambdaScopeUnsafe(S&: *this); |
1367 | LSI->Mutable = MutableLoc.isValid(); |
1368 | ContextRAII Context(*this, LSI->CallOperator, /*NewThisContext*/ false); |
1369 | |
1370 | // C++11 [expr.prim.lambda]p9: |
1371 | // A lambda-expression whose smallest enclosing scope is a block scope is a |
1372 | // local lambda expression; any other lambda expression shall not have a |
1373 | // capture-default or simple-capture in its lambda-introducer. |
1374 | // |
1375 | // For simple-captures, this is covered by the check below that any named |
1376 | // entity is a variable that can be captured. |
1377 | // |
1378 | // For DR1632, we also allow a capture-default in any context where we can |
1379 | // odr-use 'this' (in particular, in a default initializer for a non-static |
1380 | // data member). |
1381 | if (Intro.Default != LCD_None && |
1382 | !LSI->Lambda->getParent()->isFunctionOrMethod() && |
1383 | (getCurrentThisType().isNull() || |
1384 | CheckCXXThisCapture(SourceLocation(), /*Explicit=*/true, |
1385 | /*BuildAndDiagnose=*/false))) |
1386 | Diag(Intro.DefaultLoc, diag::err_capture_default_non_local); |
1387 | } |
1388 | |
1389 | void Sema::ActOnLambdaClosureParameters( |
1390 | Scope *LambdaScope, MutableArrayRef<DeclaratorChunk::ParamInfo> Params) { |
1391 | LambdaScopeInfo *LSI = getCurrentLambdaScopeUnsafe(S&: *this); |
1392 | PushDeclContext(LambdaScope, LSI->CallOperator); |
1393 | |
1394 | for (const DeclaratorChunk::ParamInfo &P : Params) { |
1395 | auto *Param = cast<ParmVarDecl>(Val: P.Param); |
1396 | Param->setOwningFunction(LSI->CallOperator); |
1397 | if (Param->getIdentifier()) |
1398 | PushOnScopeChains(Param, LambdaScope, false); |
1399 | } |
1400 | |
1401 | // After the parameter list, we may parse a noexcept/requires/trailing return |
1402 | // type which need to know whether the call operator constiture a dependent |
1403 | // context, so we need to setup the FunctionTemplateDecl of generic lambdas |
1404 | // now. |
1405 | TemplateParameterList *TemplateParams = |
1406 | getGenericLambdaTemplateParameterList(LSI, SemaRef&: *this); |
1407 | if (TemplateParams) { |
1408 | AddTemplateParametersToLambdaCallOperator(CallOperator: LSI->CallOperator, Class: LSI->Lambda, |
1409 | TemplateParams); |
1410 | LSI->Lambda->setLambdaIsGeneric(true); |
1411 | LSI->ContainsUnexpandedParameterPack |= |
1412 | TemplateParams->containsUnexpandedParameterPack(); |
1413 | } |
1414 | LSI->AfterParameterList = true; |
1415 | } |
1416 | |
1417 | void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro, |
1418 | Declarator &ParamInfo, |
1419 | const DeclSpec &DS) { |
1420 | |
1421 | LambdaScopeInfo *LSI = getCurrentLambdaScopeUnsafe(S&: *this); |
1422 | LSI->CallOperator->setConstexprKind(DS.getConstexprSpecifier()); |
1423 | |
1424 | SmallVector<ParmVarDecl *, 8> Params; |
1425 | bool ExplicitResultType; |
1426 | |
1427 | SourceLocation TypeLoc, CallOperatorLoc; |
1428 | if (ParamInfo.getNumTypeObjects() == 0) { |
1429 | CallOperatorLoc = TypeLoc = Intro.Range.getEnd(); |
1430 | } else { |
1431 | unsigned Index; |
1432 | ParamInfo.isFunctionDeclarator(idx&: Index); |
1433 | const auto &Object = ParamInfo.getTypeObject(i: Index); |
1434 | TypeLoc = |
1435 | Object.Loc.isValid() ? Object.Loc : ParamInfo.getSourceRange().getEnd(); |
1436 | CallOperatorLoc = ParamInfo.getSourceRange().getEnd(); |
1437 | } |
1438 | |
1439 | CXXRecordDecl *Class = LSI->Lambda; |
1440 | CXXMethodDecl *Method = LSI->CallOperator; |
1441 | |
1442 | TypeSourceInfo *MethodTyInfo = getLambdaType( |
1443 | S&: *this, Intro, ParamInfo, CurScope: getCurScope(), Loc: TypeLoc, ExplicitResultType); |
1444 | |
1445 | LSI->ExplicitParams = ParamInfo.getNumTypeObjects() != 0; |
1446 | |
1447 | if (ParamInfo.isFunctionDeclarator() != 0 && |
1448 | !FTIHasSingleVoidParameter(FTI: ParamInfo.getFunctionTypeInfo())) { |
1449 | const auto &FTI = ParamInfo.getFunctionTypeInfo(); |
1450 | Params.reserve(N: Params.size()); |
1451 | for (unsigned I = 0; I < FTI.NumParams; ++I) { |
1452 | auto *Param = cast<ParmVarDecl>(Val: FTI.Params[I].Param); |
1453 | Param->setScopeInfo(scopeDepth: 0, parameterIndex: Params.size()); |
1454 | Params.push_back(Elt: Param); |
1455 | } |
1456 | } |
1457 | |
1458 | bool IsLambdaStatic = |
1459 | ParamInfo.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static; |
1460 | |
1461 | CompleteLambdaCallOperator( |
1462 | Method, LambdaLoc: Intro.Range.getBegin(), CallOperatorLoc, |
1463 | TrailingRequiresClause: AssociatedConstraint(ParamInfo.getTrailingRequiresClause()), MethodTyInfo, |
1464 | ConstexprKind: ParamInfo.getDeclSpec().getConstexprSpecifier(), |
1465 | SC: IsLambdaStatic ? SC_Static : SC_None, Params, HasExplicitResultType: ExplicitResultType); |
1466 | |
1467 | CheckCXXDefaultArguments(Method); |
1468 | |
1469 | // This represents the function body for the lambda function, check if we |
1470 | // have to apply optnone due to a pragma. |
1471 | AddRangeBasedOptnone(Method); |
1472 | |
1473 | // code_seg attribute on lambda apply to the method. |
1474 | if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction( |
1475 | Method, /*IsDefinition=*/true)) |
1476 | Method->addAttr(A); |
1477 | |
1478 | // Attributes on the lambda apply to the method. |
1479 | ProcessDeclAttributes(CurScope, Method, ParamInfo); |
1480 | |
1481 | if (Context.getTargetInfo().getTriple().isAArch64()) |
1482 | ARM().CheckSMEFunctionDefAttributes(Method); |
1483 | |
1484 | // CUDA lambdas get implicit host and device attributes. |
1485 | if (getLangOpts().CUDA) |
1486 | CUDA().SetLambdaAttrs(Method); |
1487 | |
1488 | // OpenMP lambdas might get assumumption attributes. |
1489 | if (LangOpts.OpenMP) |
1490 | OpenMP().ActOnFinishedFunctionDefinitionInOpenMPAssumeScope(Method); |
1491 | |
1492 | handleLambdaNumbering(Class, Method); |
1493 | |
1494 | for (auto &&C : LSI->Captures) { |
1495 | if (!C.isVariableCapture()) |
1496 | continue; |
1497 | ValueDecl *Var = C.getVariable(); |
1498 | if (Var && Var->isInitCapture()) { |
1499 | PushOnScopeChains(Var, CurScope, false); |
1500 | } |
1501 | } |
1502 | |
1503 | auto CheckRedefinition = [&](ParmVarDecl *Param) { |
1504 | for (const auto &Capture : Intro.Captures) { |
1505 | if (Capture.Id == Param->getIdentifier()) { |
1506 | Diag(Param->getLocation(), diag::err_parameter_shadow_capture); |
1507 | Diag(Capture.Loc, diag::note_var_explicitly_captured_here) |
1508 | << Capture.Id << true; |
1509 | return false; |
1510 | } |
1511 | } |
1512 | return true; |
1513 | }; |
1514 | |
1515 | for (ParmVarDecl *P : Params) { |
1516 | if (!P->getIdentifier()) |
1517 | continue; |
1518 | if (CheckRedefinition(P)) |
1519 | CheckShadow(CurScope, P); |
1520 | PushOnScopeChains(P, CurScope); |
1521 | } |
1522 | |
1523 | // C++23 [expr.prim.lambda.capture]p5: |
1524 | // If an identifier in a capture appears as the declarator-id of a parameter |
1525 | // of the lambda-declarator's parameter-declaration-clause or as the name of a |
1526 | // template parameter of the lambda-expression's template-parameter-list, the |
1527 | // program is ill-formed. |
1528 | TemplateParameterList *TemplateParams = |
1529 | getGenericLambdaTemplateParameterList(LSI, SemaRef&: *this); |
1530 | if (TemplateParams) { |
1531 | for (const auto *TP : TemplateParams->asArray()) { |
1532 | if (!TP->getIdentifier()) |
1533 | continue; |
1534 | for (const auto &Capture : Intro.Captures) { |
1535 | if (Capture.Id == TP->getIdentifier()) { |
1536 | Diag(Capture.Loc, diag::err_template_param_shadow) << Capture.Id; |
1537 | NoteTemplateParameterLocation(Decl: *TP); |
1538 | } |
1539 | } |
1540 | } |
1541 | } |
1542 | |
1543 | // C++20: dcl.decl.general p4: |
1544 | // The optional requires-clause ([temp.pre]) in an init-declarator or |
1545 | // member-declarator shall be present only if the declarator declares a |
1546 | // templated function ([dcl.fct]). |
1547 | if (const AssociatedConstraint &TRC = Method->getTrailingRequiresClause()) { |
1548 | // [temp.pre]/8: |
1549 | // An entity is templated if it is |
1550 | // - a template, |
1551 | // - an entity defined ([basic.def]) or created ([class.temporary]) in a |
1552 | // templated entity, |
1553 | // - a member of a templated entity, |
1554 | // - an enumerator for an enumeration that is a templated entity, or |
1555 | // - the closure type of a lambda-expression ([expr.prim.lambda.closure]) |
1556 | // appearing in the declaration of a templated entity. [Note 6: A local |
1557 | // class, a local or block variable, or a friend function defined in a |
1558 | // templated entity is a templated entity. — end note] |
1559 | // |
1560 | // A templated function is a function template or a function that is |
1561 | // templated. A templated class is a class template or a class that is |
1562 | // templated. A templated variable is a variable template or a variable |
1563 | // that is templated. |
1564 | |
1565 | // Note: we only have to check if this is defined in a template entity, OR |
1566 | // if we are a template, since the rest don't apply. The requires clause |
1567 | // applies to the call operator, which we already know is a member function, |
1568 | // AND defined. |
1569 | if (!Method->getDescribedFunctionTemplate() && !Method->isTemplated()) { |
1570 | Diag(TRC.ConstraintExpr->getBeginLoc(), |
1571 | diag::err_constrained_non_templated_function); |
1572 | } |
1573 | } |
1574 | |
1575 | // Enter a new evaluation context to insulate the lambda from any |
1576 | // cleanups from the enclosing full-expression. |
1577 | PushExpressionEvaluationContextForFunction( |
1578 | ExpressionEvaluationContext::PotentiallyEvaluated, LSI->CallOperator); |
1579 | } |
1580 | |
1581 | void Sema::ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope, |
1582 | bool IsInstantiation) { |
1583 | LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(Val: FunctionScopes.back()); |
1584 | |
1585 | // Leave the expression-evaluation context. |
1586 | DiscardCleanupsInEvaluationContext(); |
1587 | PopExpressionEvaluationContext(); |
1588 | |
1589 | // Leave the context of the lambda. |
1590 | if (!IsInstantiation) |
1591 | PopDeclContext(); |
1592 | |
1593 | // Finalize the lambda. |
1594 | CXXRecordDecl *Class = LSI->Lambda; |
1595 | Class->setInvalidDecl(); |
1596 | SmallVector<Decl*, 4> Fields(Class->fields()); |
1597 | ActOnFields(S: nullptr, RecLoc: Class->getLocation(), TagDecl: Class, Fields, LBrac: SourceLocation(), |
1598 | RBrac: SourceLocation(), AttrList: ParsedAttributesView()); |
1599 | CheckCompletedCXXClass(S: nullptr, Record: Class); |
1600 | |
1601 | PopFunctionScopeInfo(); |
1602 | } |
1603 | |
1604 | template <typename Func> |
1605 | static void repeatForLambdaConversionFunctionCallingConvs( |
1606 | Sema &S, const FunctionProtoType &CallOpProto, Func F) { |
1607 | CallingConv DefaultFree = S.Context.getDefaultCallingConvention( |
1608 | IsVariadic: CallOpProto.isVariadic(), /*IsCXXMethod=*/false); |
1609 | CallingConv DefaultMember = S.Context.getDefaultCallingConvention( |
1610 | IsVariadic: CallOpProto.isVariadic(), /*IsCXXMethod=*/true); |
1611 | CallingConv CallOpCC = CallOpProto.getCallConv(); |
1612 | |
1613 | /// Implement emitting a version of the operator for many of the calling |
1614 | /// conventions for MSVC, as described here: |
1615 | /// https://devblogs.microsoft.com/oldnewthing/20150220-00/?p=44623. |
1616 | /// Experimentally, we determined that cdecl, stdcall, fastcall, and |
1617 | /// vectorcall are generated by MSVC when it is supported by the target. |
1618 | /// Additionally, we are ensuring that the default-free/default-member and |
1619 | /// call-operator calling convention are generated as well. |
1620 | /// NOTE: We intentionally generate a 'thiscall' on Win32 implicitly from the |
1621 | /// 'member default', despite MSVC not doing so. We do this in order to ensure |
1622 | /// that someone who intentionally places 'thiscall' on the lambda call |
1623 | /// operator will still get that overload, since we don't have the a way of |
1624 | /// detecting the attribute by the time we get here. |
1625 | if (S.getLangOpts().MSVCCompat) { |
1626 | CallingConv Convs[] = { |
1627 | CC_C, CC_X86StdCall, CC_X86FastCall, CC_X86VectorCall, |
1628 | DefaultFree, DefaultMember, CallOpCC}; |
1629 | llvm::sort(C&: Convs); |
1630 | llvm::iterator_range<CallingConv *> Range(std::begin(arr&: Convs), |
1631 | llvm::unique(R&: Convs)); |
1632 | const TargetInfo &TI = S.getASTContext().getTargetInfo(); |
1633 | |
1634 | for (CallingConv C : Range) { |
1635 | if (TI.checkCallingConvention(C) == TargetInfo::CCCR_OK) |
1636 | F(C); |
1637 | } |
1638 | return; |
1639 | } |
1640 | |
1641 | if (CallOpCC == DefaultMember && DefaultMember != DefaultFree) { |
1642 | F(DefaultFree); |
1643 | F(DefaultMember); |
1644 | } else { |
1645 | F(CallOpCC); |
1646 | } |
1647 | } |
1648 | |
1649 | // Returns the 'standard' calling convention to be used for the lambda |
1650 | // conversion function, that is, the 'free' function calling convention unless |
1651 | // it is overridden by a non-default calling convention attribute. |
1652 | static CallingConv |
1653 | getLambdaConversionFunctionCallConv(Sema &S, |
1654 | const FunctionProtoType *CallOpProto) { |
1655 | CallingConv DefaultFree = S.Context.getDefaultCallingConvention( |
1656 | IsVariadic: CallOpProto->isVariadic(), /*IsCXXMethod=*/false); |
1657 | CallingConv DefaultMember = S.Context.getDefaultCallingConvention( |
1658 | IsVariadic: CallOpProto->isVariadic(), /*IsCXXMethod=*/true); |
1659 | CallingConv CallOpCC = CallOpProto->getCallConv(); |
1660 | |
1661 | // If the call-operator hasn't been changed, return both the 'free' and |
1662 | // 'member' function calling convention. |
1663 | if (CallOpCC == DefaultMember && DefaultMember != DefaultFree) |
1664 | return DefaultFree; |
1665 | return CallOpCC; |
1666 | } |
1667 | |
1668 | QualType Sema::getLambdaConversionFunctionResultType( |
1669 | const FunctionProtoType *CallOpProto, CallingConv CC) { |
1670 | const FunctionProtoType::ExtProtoInfo CallOpExtInfo = |
1671 | CallOpProto->getExtProtoInfo(); |
1672 | FunctionProtoType::ExtProtoInfo InvokerExtInfo = CallOpExtInfo; |
1673 | InvokerExtInfo.ExtInfo = InvokerExtInfo.ExtInfo.withCallingConv(cc: CC); |
1674 | InvokerExtInfo.TypeQuals = Qualifiers(); |
1675 | assert(InvokerExtInfo.RefQualifier == RQ_None && |
1676 | "Lambda's call operator should not have a reference qualifier"); |
1677 | return Context.getFunctionType(ResultTy: CallOpProto->getReturnType(), |
1678 | Args: CallOpProto->getParamTypes(), EPI: InvokerExtInfo); |
1679 | } |
1680 | |
1681 | /// Add a lambda's conversion to function pointer, as described in |
1682 | /// C++11 [expr.prim.lambda]p6. |
1683 | static void addFunctionPointerConversion(Sema &S, SourceRange IntroducerRange, |
1684 | CXXRecordDecl *Class, |
1685 | CXXMethodDecl *CallOperator, |
1686 | QualType InvokerFunctionTy) { |
1687 | // This conversion is explicitly disabled if the lambda's function has |
1688 | // pass_object_size attributes on any of its parameters. |
1689 | auto HasPassObjectSizeAttr = [](const ParmVarDecl *P) { |
1690 | return P->hasAttr<PassObjectSizeAttr>(); |
1691 | }; |
1692 | if (llvm::any_of(CallOperator->parameters(), HasPassObjectSizeAttr)) |
1693 | return; |
1694 | |
1695 | // Add the conversion to function pointer. |
1696 | QualType PtrToFunctionTy = S.Context.getPointerType(T: InvokerFunctionTy); |
1697 | |
1698 | // Create the type of the conversion function. |
1699 | FunctionProtoType::ExtProtoInfo ConvExtInfo( |
1700 | S.Context.getDefaultCallingConvention( |
1701 | /*IsVariadic=*/false, /*IsCXXMethod=*/true)); |
1702 | // The conversion function is always const and noexcept. |
1703 | ConvExtInfo.TypeQuals = Qualifiers(); |
1704 | ConvExtInfo.TypeQuals.addConst(); |
1705 | ConvExtInfo.ExceptionSpec.Type = EST_BasicNoexcept; |
1706 | QualType ConvTy = S.Context.getFunctionType(ResultTy: PtrToFunctionTy, Args: {}, EPI: ConvExtInfo); |
1707 | |
1708 | SourceLocation Loc = IntroducerRange.getBegin(); |
1709 | DeclarationName ConversionName |
1710 | = S.Context.DeclarationNames.getCXXConversionFunctionName( |
1711 | Ty: S.Context.getCanonicalType(T: PtrToFunctionTy)); |
1712 | // Construct a TypeSourceInfo for the conversion function, and wire |
1713 | // all the parameters appropriately for the FunctionProtoTypeLoc |
1714 | // so that everything works during transformation/instantiation of |
1715 | // generic lambdas. |
1716 | // The main reason for wiring up the parameters of the conversion |
1717 | // function with that of the call operator is so that constructs |
1718 | // like the following work: |
1719 | // auto L = [](auto b) { <-- 1 |
1720 | // return [](auto a) -> decltype(a) { <-- 2 |
1721 | // return a; |
1722 | // }; |
1723 | // }; |
1724 | // int (*fp)(int) = L(5); |
1725 | // Because the trailing return type can contain DeclRefExprs that refer |
1726 | // to the original call operator's variables, we hijack the call |
1727 | // operators ParmVarDecls below. |
1728 | TypeSourceInfo *ConvNamePtrToFunctionTSI = |
1729 | S.Context.getTrivialTypeSourceInfo(T: PtrToFunctionTy, Loc); |
1730 | DeclarationNameLoc ConvNameLoc = |
1731 | DeclarationNameLoc::makeNamedTypeLoc(TInfo: ConvNamePtrToFunctionTSI); |
1732 | |
1733 | // The conversion function is a conversion to a pointer-to-function. |
1734 | TypeSourceInfo *ConvTSI = S.Context.getTrivialTypeSourceInfo(T: ConvTy, Loc); |
1735 | FunctionProtoTypeLoc ConvTL = |
1736 | ConvTSI->getTypeLoc().getAs<FunctionProtoTypeLoc>(); |
1737 | // Get the result of the conversion function which is a pointer-to-function. |
1738 | PointerTypeLoc PtrToFunctionTL = |
1739 | ConvTL.getReturnLoc().getAs<PointerTypeLoc>(); |
1740 | // Do the same for the TypeSourceInfo that is used to name the conversion |
1741 | // operator. |
1742 | PointerTypeLoc ConvNamePtrToFunctionTL = |
1743 | ConvNamePtrToFunctionTSI->getTypeLoc().getAs<PointerTypeLoc>(); |
1744 | |
1745 | // Get the underlying function types that the conversion function will |
1746 | // be converting to (should match the type of the call operator). |
1747 | FunctionProtoTypeLoc CallOpConvTL = |
1748 | PtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>(); |
1749 | FunctionProtoTypeLoc CallOpConvNameTL = |
1750 | ConvNamePtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>(); |
1751 | |
1752 | // Wire up the FunctionProtoTypeLocs with the call operator's parameters. |
1753 | // These parameter's are essentially used to transform the name and |
1754 | // the type of the conversion operator. By using the same parameters |
1755 | // as the call operator's we don't have to fix any back references that |
1756 | // the trailing return type of the call operator's uses (such as |
1757 | // decltype(some_type<decltype(a)>::type{} + decltype(a){}) etc.) |
1758 | // - we can simply use the return type of the call operator, and |
1759 | // everything should work. |
1760 | SmallVector<ParmVarDecl *, 4> InvokerParams; |
1761 | for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) { |
1762 | ParmVarDecl *From = CallOperator->getParamDecl(I); |
1763 | |
1764 | InvokerParams.push_back(Elt: ParmVarDecl::Create( |
1765 | C&: S.Context, |
1766 | // Temporarily add to the TU. This is set to the invoker below. |
1767 | DC: S.Context.getTranslationUnitDecl(), StartLoc: From->getBeginLoc(), |
1768 | IdLoc: From->getLocation(), Id: From->getIdentifier(), T: From->getType(), |
1769 | TInfo: From->getTypeSourceInfo(), S: From->getStorageClass(), |
1770 | /*DefArg=*/nullptr)); |
1771 | CallOpConvTL.setParam(I, From); |
1772 | CallOpConvNameTL.setParam(I, From); |
1773 | } |
1774 | |
1775 | CXXConversionDecl *Conversion = CXXConversionDecl::Create( |
1776 | C&: S.Context, RD: Class, StartLoc: Loc, |
1777 | NameInfo: DeclarationNameInfo(ConversionName, Loc, ConvNameLoc), T: ConvTy, TInfo: ConvTSI, |
1778 | UsesFPIntrin: S.getCurFPFeatures().isFPConstrained(), |
1779 | /*isInline=*/true, ES: ExplicitSpecifier(), |
1780 | ConstexprKind: S.getLangOpts().CPlusPlus17 ? ConstexprSpecKind::Constexpr |
1781 | : ConstexprSpecKind::Unspecified, |
1782 | EndLocation: CallOperator->getBody()->getEndLoc()); |
1783 | Conversion->setAccess(AS_public); |
1784 | Conversion->setImplicit(true); |
1785 | |
1786 | // A non-generic lambda may still be a templated entity. We need to preserve |
1787 | // constraints when converting the lambda to a function pointer. See GH63181. |
1788 | if (const AssociatedConstraint &Requires = |
1789 | CallOperator->getTrailingRequiresClause()) |
1790 | Conversion->setTrailingRequiresClause(Requires); |
1791 | |
1792 | if (Class->isGenericLambda()) { |
1793 | // Create a template version of the conversion operator, using the template |
1794 | // parameter list of the function call operator. |
1795 | FunctionTemplateDecl *TemplateCallOperator = |
1796 | CallOperator->getDescribedFunctionTemplate(); |
1797 | FunctionTemplateDecl *ConversionTemplate = |
1798 | FunctionTemplateDecl::Create(C&: S.Context, DC: Class, |
1799 | L: Loc, Name: ConversionName, |
1800 | Params: TemplateCallOperator->getTemplateParameters(), |
1801 | Decl: Conversion); |
1802 | ConversionTemplate->setAccess(AS_public); |
1803 | ConversionTemplate->setImplicit(true); |
1804 | Conversion->setDescribedFunctionTemplate(ConversionTemplate); |
1805 | Class->addDecl(ConversionTemplate); |
1806 | } else |
1807 | Class->addDecl(Conversion); |
1808 | |
1809 | // If the lambda is not static, we need to add a static member |
1810 | // function that will be the result of the conversion with a |
1811 | // certain unique ID. |
1812 | // When it is static we just return the static call operator instead. |
1813 | if (CallOperator->isImplicitObjectMemberFunction()) { |
1814 | DeclarationName InvokerName = |
1815 | &S.Context.Idents.get(Name: getLambdaStaticInvokerName()); |
1816 | // FIXME: Instead of passing in the CallOperator->getTypeSourceInfo() |
1817 | // we should get a prebuilt TrivialTypeSourceInfo from Context |
1818 | // using FunctionTy & Loc and get its TypeLoc as a FunctionProtoTypeLoc |
1819 | // then rewire the parameters accordingly, by hoisting up the InvokeParams |
1820 | // loop below and then use its Params to set Invoke->setParams(...) below. |
1821 | // This would avoid the 'const' qualifier of the calloperator from |
1822 | // contaminating the type of the invoker, which is currently adjusted |
1823 | // in SemaTemplateDeduction.cpp:DeduceTemplateArguments. Fixing the |
1824 | // trailing return type of the invoker would require a visitor to rebuild |
1825 | // the trailing return type and adjusting all back DeclRefExpr's to refer |
1826 | // to the new static invoker parameters - not the call operator's. |
1827 | CXXMethodDecl *Invoke = CXXMethodDecl::Create( |
1828 | C&: S.Context, RD: Class, StartLoc: Loc, NameInfo: DeclarationNameInfo(InvokerName, Loc), |
1829 | T: InvokerFunctionTy, TInfo: CallOperator->getTypeSourceInfo(), SC: SC_Static, |
1830 | UsesFPIntrin: S.getCurFPFeatures().isFPConstrained(), |
1831 | /*isInline=*/true, ConstexprKind: CallOperator->getConstexprKind(), |
1832 | EndLocation: CallOperator->getBody()->getEndLoc()); |
1833 | for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) |
1834 | InvokerParams[I]->setOwningFunction(Invoke); |
1835 | Invoke->setParams(InvokerParams); |
1836 | Invoke->setAccess(AS_private); |
1837 | Invoke->setImplicit(true); |
1838 | if (Class->isGenericLambda()) { |
1839 | FunctionTemplateDecl *TemplateCallOperator = |
1840 | CallOperator->getDescribedFunctionTemplate(); |
1841 | FunctionTemplateDecl *StaticInvokerTemplate = |
1842 | FunctionTemplateDecl::Create( |
1843 | C&: S.Context, DC: Class, L: Loc, Name: InvokerName, |
1844 | Params: TemplateCallOperator->getTemplateParameters(), Decl: Invoke); |
1845 | StaticInvokerTemplate->setAccess(AS_private); |
1846 | StaticInvokerTemplate->setImplicit(true); |
1847 | Invoke->setDescribedFunctionTemplate(StaticInvokerTemplate); |
1848 | Class->addDecl(StaticInvokerTemplate); |
1849 | } else |
1850 | Class->addDecl(Invoke); |
1851 | } |
1852 | } |
1853 | |
1854 | /// Add a lambda's conversion to function pointers, as described in |
1855 | /// C++11 [expr.prim.lambda]p6. Note that in most cases, this should emit only a |
1856 | /// single pointer conversion. In the event that the default calling convention |
1857 | /// for free and member functions is different, it will emit both conventions. |
1858 | static void addFunctionPointerConversions(Sema &S, SourceRange IntroducerRange, |
1859 | CXXRecordDecl *Class, |
1860 | CXXMethodDecl *CallOperator) { |
1861 | const FunctionProtoType *CallOpProto = |
1862 | CallOperator->getType()->castAs<FunctionProtoType>(); |
1863 | |
1864 | repeatForLambdaConversionFunctionCallingConvs( |
1865 | S, CallOpProto: *CallOpProto, F: [&](CallingConv CC) { |
1866 | QualType InvokerFunctionTy = |
1867 | S.getLambdaConversionFunctionResultType(CallOpProto, CC); |
1868 | addFunctionPointerConversion(S, IntroducerRange, Class, CallOperator, |
1869 | InvokerFunctionTy); |
1870 | }); |
1871 | } |
1872 | |
1873 | /// Add a lambda's conversion to block pointer. |
1874 | static void addBlockPointerConversion(Sema &S, |
1875 | SourceRange IntroducerRange, |
1876 | CXXRecordDecl *Class, |
1877 | CXXMethodDecl *CallOperator) { |
1878 | const FunctionProtoType *CallOpProto = |
1879 | CallOperator->getType()->castAs<FunctionProtoType>(); |
1880 | QualType FunctionTy = S.getLambdaConversionFunctionResultType( |
1881 | CallOpProto, CC: getLambdaConversionFunctionCallConv(S, CallOpProto)); |
1882 | QualType BlockPtrTy = S.Context.getBlockPointerType(T: FunctionTy); |
1883 | |
1884 | FunctionProtoType::ExtProtoInfo ConversionEPI( |
1885 | S.Context.getDefaultCallingConvention( |
1886 | /*IsVariadic=*/false, /*IsCXXMethod=*/true)); |
1887 | ConversionEPI.TypeQuals = Qualifiers(); |
1888 | ConversionEPI.TypeQuals.addConst(); |
1889 | QualType ConvTy = S.Context.getFunctionType(ResultTy: BlockPtrTy, Args: {}, EPI: ConversionEPI); |
1890 | |
1891 | SourceLocation Loc = IntroducerRange.getBegin(); |
1892 | DeclarationName Name |
1893 | = S.Context.DeclarationNames.getCXXConversionFunctionName( |
1894 | Ty: S.Context.getCanonicalType(T: BlockPtrTy)); |
1895 | DeclarationNameLoc NameLoc = DeclarationNameLoc::makeNamedTypeLoc( |
1896 | TInfo: S.Context.getTrivialTypeSourceInfo(T: BlockPtrTy, Loc)); |
1897 | CXXConversionDecl *Conversion = CXXConversionDecl::Create( |
1898 | C&: S.Context, RD: Class, StartLoc: Loc, NameInfo: DeclarationNameInfo(Name, Loc, NameLoc), T: ConvTy, |
1899 | TInfo: S.Context.getTrivialTypeSourceInfo(T: ConvTy, Loc), |
1900 | UsesFPIntrin: S.getCurFPFeatures().isFPConstrained(), |
1901 | /*isInline=*/true, ES: ExplicitSpecifier(), ConstexprKind: ConstexprSpecKind::Unspecified, |
1902 | EndLocation: CallOperator->getBody()->getEndLoc()); |
1903 | Conversion->setAccess(AS_public); |
1904 | Conversion->setImplicit(true); |
1905 | Class->addDecl(Conversion); |
1906 | } |
1907 | |
1908 | ExprResult Sema::BuildCaptureInit(const Capture &Cap, |
1909 | SourceLocation ImplicitCaptureLoc, |
1910 | bool IsOpenMPMapping) { |
1911 | // VLA captures don't have a stored initialization expression. |
1912 | if (Cap.isVLATypeCapture()) |
1913 | return ExprResult(); |
1914 | |
1915 | // An init-capture is initialized directly from its stored initializer. |
1916 | if (Cap.isInitCapture()) |
1917 | return cast<VarDecl>(Val: Cap.getVariable())->getInit(); |
1918 | |
1919 | // For anything else, build an initialization expression. For an implicit |
1920 | // capture, the capture notionally happens at the capture-default, so use |
1921 | // that location here. |
1922 | SourceLocation Loc = |
1923 | ImplicitCaptureLoc.isValid() ? ImplicitCaptureLoc : Cap.getLocation(); |
1924 | |
1925 | // C++11 [expr.prim.lambda]p21: |
1926 | // When the lambda-expression is evaluated, the entities that |
1927 | // are captured by copy are used to direct-initialize each |
1928 | // corresponding non-static data member of the resulting closure |
1929 | // object. (For array members, the array elements are |
1930 | // direct-initialized in increasing subscript order.) These |
1931 | // initializations are performed in the (unspecified) order in |
1932 | // which the non-static data members are declared. |
1933 | |
1934 | // C++ [expr.prim.lambda]p12: |
1935 | // An entity captured by a lambda-expression is odr-used (3.2) in |
1936 | // the scope containing the lambda-expression. |
1937 | ExprResult Init; |
1938 | IdentifierInfo *Name = nullptr; |
1939 | if (Cap.isThisCapture()) { |
1940 | QualType ThisTy = getCurrentThisType(); |
1941 | Expr *This = BuildCXXThisExpr(Loc, Type: ThisTy, IsImplicit: ImplicitCaptureLoc.isValid()); |
1942 | if (Cap.isCopyCapture()) |
1943 | Init = CreateBuiltinUnaryOp(OpLoc: Loc, Opc: UO_Deref, InputExpr: This); |
1944 | else |
1945 | Init = This; |
1946 | } else { |
1947 | assert(Cap.isVariableCapture() && "unknown kind of capture"); |
1948 | ValueDecl *Var = Cap.getVariable(); |
1949 | Name = Var->getIdentifier(); |
1950 | Init = BuildDeclarationNameExpr( |
1951 | CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var); |
1952 | } |
1953 | |
1954 | // In OpenMP, the capture kind doesn't actually describe how to capture: |
1955 | // variables are "mapped" onto the device in a process that does not formally |
1956 | // make a copy, even for a "copy capture". |
1957 | if (IsOpenMPMapping) |
1958 | return Init; |
1959 | |
1960 | if (Init.isInvalid()) |
1961 | return ExprError(); |
1962 | |
1963 | Expr *InitExpr = Init.get(); |
1964 | InitializedEntity Entity = InitializedEntity::InitializeLambdaCapture( |
1965 | VarID: Name, FieldType: Cap.getCaptureType(), Loc); |
1966 | InitializationKind InitKind = |
1967 | InitializationKind::CreateDirect(InitLoc: Loc, LParenLoc: Loc, RParenLoc: Loc); |
1968 | InitializationSequence InitSeq(*this, Entity, InitKind, InitExpr); |
1969 | return InitSeq.Perform(S&: *this, Entity, Kind: InitKind, Args: InitExpr); |
1970 | } |
1971 | |
1972 | ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body) { |
1973 | LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(Val: FunctionScopes.back()); |
1974 | |
1975 | if (LSI.CallOperator->hasAttr<SYCLKernelEntryPointAttr>()) |
1976 | SYCL().CheckSYCLEntryPointFunctionDecl(LSI.CallOperator); |
1977 | |
1978 | ActOnFinishFunctionBody(LSI.CallOperator, Body); |
1979 | |
1980 | return BuildLambdaExpr(StartLoc, EndLoc: Body->getEndLoc(), LSI: &LSI); |
1981 | } |
1982 | |
1983 | static LambdaCaptureDefault |
1984 | mapImplicitCaptureStyle(CapturingScopeInfo::ImplicitCaptureStyle ICS) { |
1985 | switch (ICS) { |
1986 | case CapturingScopeInfo::ImpCap_None: |
1987 | return LCD_None; |
1988 | case CapturingScopeInfo::ImpCap_LambdaByval: |
1989 | return LCD_ByCopy; |
1990 | case CapturingScopeInfo::ImpCap_CapturedRegion: |
1991 | case CapturingScopeInfo::ImpCap_LambdaByref: |
1992 | return LCD_ByRef; |
1993 | case CapturingScopeInfo::ImpCap_Block: |
1994 | llvm_unreachable("block capture in lambda"); |
1995 | } |
1996 | llvm_unreachable("Unknown implicit capture style"); |
1997 | } |
1998 | |
1999 | bool Sema::CaptureHasSideEffects(const Capture &From) { |
2000 | if (From.isInitCapture()) { |
2001 | Expr *Init = cast<VarDecl>(Val: From.getVariable())->getInit(); |
2002 | if (Init && Init->HasSideEffects(Ctx: Context)) |
2003 | return true; |
2004 | } |
2005 | |
2006 | if (!From.isCopyCapture()) |
2007 | return false; |
2008 | |
2009 | const QualType T = From.isThisCapture() |
2010 | ? getCurrentThisType()->getPointeeType() |
2011 | : From.getCaptureType(); |
2012 | |
2013 | if (T.isVolatileQualified()) |
2014 | return true; |
2015 | |
2016 | const Type *BaseT = T->getBaseElementTypeUnsafe(); |
2017 | if (const CXXRecordDecl *RD = BaseT->getAsCXXRecordDecl()) |
2018 | return !RD->isCompleteDefinition() || !RD->hasTrivialCopyConstructor() || |
2019 | !RD->hasTrivialDestructor(); |
2020 | |
2021 | return false; |
2022 | } |
2023 | |
2024 | bool Sema::DiagnoseUnusedLambdaCapture(SourceRange CaptureRange, |
2025 | SourceRange FixItRange, |
2026 | const Capture &From) { |
2027 | if (CaptureHasSideEffects(From)) |
2028 | return false; |
2029 | |
2030 | if (From.isVLATypeCapture()) |
2031 | return false; |
2032 | |
2033 | // FIXME: maybe we should warn on these if we can find a sensible diagnostic |
2034 | // message |
2035 | if (From.isInitCapture() && |
2036 | From.getVariable()->isPlaceholderVar(getLangOpts())) |
2037 | return false; |
2038 | |
2039 | auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture); |
2040 | if (From.isThisCapture()) |
2041 | diag << "'this'"; |
2042 | else |
2043 | diag << From.getVariable(); |
2044 | diag << From.isNonODRUsed(); |
2045 | // If we were able to resolve the fixit range we'll create a fixit, |
2046 | // otherwise we just use the raw capture range for the diagnostic. |
2047 | if (FixItRange.isValid()) |
2048 | diag << FixItHint::CreateRemoval(RemoveRange: FixItRange); |
2049 | else |
2050 | diag << CaptureRange; |
2051 | return true; |
2052 | } |
2053 | |
2054 | /// Create a field within the lambda class or captured statement record for the |
2055 | /// given capture. |
2056 | FieldDecl *Sema::BuildCaptureField(RecordDecl *RD, |
2057 | const sema::Capture &Capture) { |
2058 | SourceLocation Loc = Capture.getLocation(); |
2059 | QualType FieldType = Capture.getCaptureType(); |
2060 | |
2061 | TypeSourceInfo *TSI = nullptr; |
2062 | if (Capture.isVariableCapture()) { |
2063 | const auto *Var = dyn_cast_or_null<VarDecl>(Val: Capture.getVariable()); |
2064 | if (Var && Var->isInitCapture()) |
2065 | TSI = Var->getTypeSourceInfo(); |
2066 | } |
2067 | |
2068 | // FIXME: Should we really be doing this? A null TypeSourceInfo seems more |
2069 | // appropriate, at least for an implicit capture. |
2070 | if (!TSI) |
2071 | TSI = Context.getTrivialTypeSourceInfo(T: FieldType, Loc); |
2072 | |
2073 | // Build the non-static data member. |
2074 | FieldDecl *Field = |
2075 | FieldDecl::Create(Context, RD, /*StartLoc=*/Loc, /*IdLoc=*/Loc, |
2076 | /*Id=*/nullptr, FieldType, TSI, /*BW=*/nullptr, |
2077 | /*Mutable=*/false, ICIS_NoInit); |
2078 | // If the variable being captured has an invalid type, mark the class as |
2079 | // invalid as well. |
2080 | if (!FieldType->isDependentType()) { |
2081 | if (RequireCompleteSizedType(Loc, FieldType, |
2082 | diag::err_field_incomplete_or_sizeless)) { |
2083 | RD->setInvalidDecl(); |
2084 | Field->setInvalidDecl(); |
2085 | } else { |
2086 | NamedDecl *Def; |
2087 | FieldType->isIncompleteType(Def: &Def); |
2088 | if (Def && Def->isInvalidDecl()) { |
2089 | RD->setInvalidDecl(); |
2090 | Field->setInvalidDecl(); |
2091 | } |
2092 | } |
2093 | } |
2094 | Field->setImplicit(true); |
2095 | Field->setAccess(AS_private); |
2096 | RD->addDecl(Field); |
2097 | |
2098 | if (Capture.isVLATypeCapture()) |
2099 | Field->setCapturedVLAType(Capture.getCapturedVLAType()); |
2100 | |
2101 | return Field; |
2102 | } |
2103 | |
2104 | static SourceRange |
2105 | ConstructFixItRangeForUnusedCapture(Sema &S, SourceRange CaptureRange, |
2106 | SourceLocation PrevCaptureLoc, |
2107 | bool CurHasPreviousCapture, bool IsLast) { |
2108 | if (!CaptureRange.isValid()) |
2109 | return SourceRange(); |
2110 | |
2111 | auto GetTrailingEndLocation = [&](SourceLocation StartPoint) { |
2112 | SourceRange NextToken = S.getRangeForNextToken( |
2113 | Loc: StartPoint, /*IncludeMacros=*/false, /*IncludeComments=*/true); |
2114 | if (!NextToken.isValid()) |
2115 | return SourceLocation(); |
2116 | // Return the last location preceding the next token |
2117 | return NextToken.getBegin().getLocWithOffset(Offset: -1); |
2118 | }; |
2119 | |
2120 | if (!CurHasPreviousCapture && !IsLast) { |
2121 | // If there are no captures preceding this capture, remove the |
2122 | // trailing comma and anything up to the next token |
2123 | SourceRange CommaRange = |
2124 | S.getRangeForNextToken(Loc: CaptureRange.getEnd(), /*IncludeMacros=*/false, |
2125 | /*IncludeComments=*/false, ExpectedToken: tok::comma); |
2126 | SourceLocation FixItEnd = GetTrailingEndLocation(CommaRange.getBegin()); |
2127 | return SourceRange(CaptureRange.getBegin(), FixItEnd); |
2128 | } |
2129 | |
2130 | // Otherwise, remove the comma since the last used capture, and |
2131 | // anything up to the next token |
2132 | SourceLocation FixItStart = S.getLocForEndOfToken(Loc: PrevCaptureLoc); |
2133 | SourceLocation FixItEnd = GetTrailingEndLocation(CaptureRange.getEnd()); |
2134 | return SourceRange(FixItStart, FixItEnd); |
2135 | } |
2136 | |
2137 | ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc, |
2138 | LambdaScopeInfo *LSI) { |
2139 | // Collect information from the lambda scope. |
2140 | SmallVector<LambdaCapture, 4> Captures; |
2141 | SmallVector<Expr *, 4> CaptureInits; |
2142 | SourceLocation CaptureDefaultLoc = LSI->CaptureDefaultLoc; |
2143 | LambdaCaptureDefault CaptureDefault = |
2144 | mapImplicitCaptureStyle(ICS: LSI->ImpCaptureStyle); |
2145 | CXXRecordDecl *Class; |
2146 | CXXMethodDecl *CallOperator; |
2147 | SourceRange IntroducerRange; |
2148 | bool ExplicitParams; |
2149 | bool ExplicitResultType; |
2150 | CleanupInfo LambdaCleanup; |
2151 | bool ContainsUnexpandedParameterPack; |
2152 | bool IsGenericLambda; |
2153 | { |
2154 | CallOperator = LSI->CallOperator; |
2155 | Class = LSI->Lambda; |
2156 | IntroducerRange = LSI->IntroducerRange; |
2157 | ExplicitParams = LSI->ExplicitParams; |
2158 | ExplicitResultType = !LSI->HasImplicitReturnType; |
2159 | LambdaCleanup = LSI->Cleanup; |
2160 | ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack; |
2161 | IsGenericLambda = Class->isGenericLambda(); |
2162 | |
2163 | CallOperator->setLexicalDeclContext(Class); |
2164 | Decl *TemplateOrNonTemplateCallOperatorDecl = |
2165 | CallOperator->getDescribedFunctionTemplate() |
2166 | ? CallOperator->getDescribedFunctionTemplate() |
2167 | : cast<Decl>(Val: CallOperator); |
2168 | |
2169 | // FIXME: Is this really the best choice? Keeping the lexical decl context |
2170 | // set as CurContext seems more faithful to the source. |
2171 | TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class); |
2172 | |
2173 | PopExpressionEvaluationContext(); |
2174 | |
2175 | // True if the current capture has a used capture or default before it. |
2176 | bool CurHasPreviousCapture = CaptureDefault != LCD_None; |
2177 | SourceLocation PrevCaptureLoc = CurHasPreviousCapture ? |
2178 | CaptureDefaultLoc : IntroducerRange.getBegin(); |
2179 | |
2180 | for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I) { |
2181 | const Capture &From = LSI->Captures[I]; |
2182 | |
2183 | if (From.isInvalid()) |
2184 | return ExprError(); |
2185 | |
2186 | assert(!From.isBlockCapture() && "Cannot capture __block variables"); |
2187 | bool IsImplicit = I >= LSI->NumExplicitCaptures; |
2188 | SourceLocation ImplicitCaptureLoc = |
2189 | IsImplicit ? CaptureDefaultLoc : SourceLocation(); |
2190 | |
2191 | // Use source ranges of explicit captures for fixits where available. |
2192 | SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I]; |
2193 | |
2194 | // Warn about unused explicit captures. |
2195 | bool IsCaptureUsed = true; |
2196 | if (!CurContext->isDependentContext() && !IsImplicit && |
2197 | !From.isODRUsed()) { |
2198 | // Initialized captures that are non-ODR used may not be eliminated. |
2199 | // FIXME: Where did the IsGenericLambda here come from? |
2200 | bool NonODRUsedInitCapture = |
2201 | IsGenericLambda && From.isNonODRUsed() && From.isInitCapture(); |
2202 | if (!NonODRUsedInitCapture) { |
2203 | bool IsLast = (I + 1) == LSI->NumExplicitCaptures; |
2204 | SourceRange FixItRange = ConstructFixItRangeForUnusedCapture( |
2205 | S&: *this, CaptureRange, PrevCaptureLoc, CurHasPreviousCapture, |
2206 | IsLast); |
2207 | IsCaptureUsed = |
2208 | !DiagnoseUnusedLambdaCapture(CaptureRange, FixItRange, From); |
2209 | } |
2210 | } |
2211 | |
2212 | if (CaptureRange.isValid()) { |
2213 | CurHasPreviousCapture |= IsCaptureUsed; |
2214 | PrevCaptureLoc = CaptureRange.getEnd(); |
2215 | } |
2216 | |
2217 | // Map the capture to our AST representation. |
2218 | LambdaCapture Capture = [&] { |
2219 | if (From.isThisCapture()) { |
2220 | // Capturing 'this' implicitly with a default of '[=]' is deprecated, |
2221 | // because it results in a reference capture. Don't warn prior to |
2222 | // C++2a; there's nothing that can be done about it before then. |
2223 | if (getLangOpts().CPlusPlus20 && IsImplicit && |
2224 | CaptureDefault == LCD_ByCopy) { |
2225 | Diag(From.getLocation(), diag::warn_deprecated_this_capture); |
2226 | Diag(CaptureDefaultLoc, diag::note_deprecated_this_capture) |
2227 | << FixItHint::CreateInsertion( |
2228 | getLocForEndOfToken(CaptureDefaultLoc), ", this"); |
2229 | } |
2230 | return LambdaCapture(From.getLocation(), IsImplicit, |
2231 | From.isCopyCapture() ? LCK_StarThis : LCK_This); |
2232 | } else if (From.isVLATypeCapture()) { |
2233 | return LambdaCapture(From.getLocation(), IsImplicit, LCK_VLAType); |
2234 | } else { |
2235 | assert(From.isVariableCapture() && "unknown kind of capture"); |
2236 | ValueDecl *Var = From.getVariable(); |
2237 | LambdaCaptureKind Kind = |
2238 | From.isCopyCapture() ? LCK_ByCopy : LCK_ByRef; |
2239 | return LambdaCapture(From.getLocation(), IsImplicit, Kind, Var, |
2240 | From.getEllipsisLoc()); |
2241 | } |
2242 | }(); |
2243 | |
2244 | // Form the initializer for the capture field. |
2245 | ExprResult Init = BuildCaptureInit(Cap: From, ImplicitCaptureLoc); |
2246 | |
2247 | // FIXME: Skip this capture if the capture is not used, the initializer |
2248 | // has no side-effects, the type of the capture is trivial, and the |
2249 | // lambda is not externally visible. |
2250 | |
2251 | // Add a FieldDecl for the capture and form its initializer. |
2252 | BuildCaptureField(Class, From); |
2253 | Captures.push_back(Elt: Capture); |
2254 | CaptureInits.push_back(Elt: Init.get()); |
2255 | |
2256 | if (LangOpts.CUDA) |
2257 | CUDA().CheckLambdaCapture(D: CallOperator, Capture: From); |
2258 | } |
2259 | |
2260 | Class->setCaptures(Context, Captures); |
2261 | |
2262 | // C++11 [expr.prim.lambda]p6: |
2263 | // The closure type for a lambda-expression with no lambda-capture |
2264 | // has a public non-virtual non-explicit const conversion function |
2265 | // to pointer to function having the same parameter and return |
2266 | // types as the closure type's function call operator. |
2267 | if (Captures.empty() && CaptureDefault == LCD_None) |
2268 | addFunctionPointerConversions(S&: *this, IntroducerRange, Class, |
2269 | CallOperator); |
2270 | |
2271 | // Objective-C++: |
2272 | // The closure type for a lambda-expression has a public non-virtual |
2273 | // non-explicit const conversion function to a block pointer having the |
2274 | // same parameter and return types as the closure type's function call |
2275 | // operator. |
2276 | // FIXME: Fix generic lambda to block conversions. |
2277 | if (getLangOpts().Blocks && getLangOpts().ObjC && !IsGenericLambda) |
2278 | addBlockPointerConversion(S&: *this, IntroducerRange, Class, CallOperator); |
2279 | |
2280 | // Finalize the lambda class. |
2281 | SmallVector<Decl*, 4> Fields(Class->fields()); |
2282 | ActOnFields(S: nullptr, RecLoc: Class->getLocation(), TagDecl: Class, Fields, LBrac: SourceLocation(), |
2283 | RBrac: SourceLocation(), AttrList: ParsedAttributesView()); |
2284 | CheckCompletedCXXClass(S: nullptr, Record: Class); |
2285 | } |
2286 | |
2287 | Cleanup.mergeFrom(Rhs: LambdaCleanup); |
2288 | |
2289 | LambdaExpr *Lambda = |
2290 | LambdaExpr::Create(C: Context, Class, IntroducerRange, CaptureDefault, |
2291 | CaptureDefaultLoc, ExplicitParams, ExplicitResultType, |
2292 | CaptureInits, ClosingBrace: EndLoc, ContainsUnexpandedParameterPack); |
2293 | |
2294 | // If the lambda expression's call operator is not explicitly marked constexpr |
2295 | // and is not dependent, analyze the call operator to infer |
2296 | // its constexpr-ness, suppressing diagnostics while doing so. |
2297 | if (getLangOpts().CPlusPlus17 && !CallOperator->isInvalidDecl() && |
2298 | !CallOperator->isConstexpr() && |
2299 | !isa<CoroutineBodyStmt>(Val: CallOperator->getBody()) && |
2300 | !Class->isDependentContext()) { |
2301 | CallOperator->setConstexprKind( |
2302 | CheckConstexprFunctionDefinition(CallOperator, |
2303 | CheckConstexprKind::CheckValid) |
2304 | ? ConstexprSpecKind::Constexpr |
2305 | : ConstexprSpecKind::Unspecified); |
2306 | } |
2307 | |
2308 | // Emit delayed shadowing warnings now that the full capture list is known. |
2309 | DiagnoseShadowingLambdaDecls(LSI); |
2310 | |
2311 | if (!CurContext->isDependentContext()) { |
2312 | switch (ExprEvalContexts.back().Context) { |
2313 | // C++11 [expr.prim.lambda]p2: |
2314 | // A lambda-expression shall not appear in an unevaluated operand |
2315 | // (Clause 5). |
2316 | case ExpressionEvaluationContext::Unevaluated: |
2317 | case ExpressionEvaluationContext::UnevaluatedList: |
2318 | case ExpressionEvaluationContext::UnevaluatedAbstract: |
2319 | // C++1y [expr.const]p2: |
2320 | // A conditional-expression e is a core constant expression unless the |
2321 | // evaluation of e, following the rules of the abstract machine, would |
2322 | // evaluate [...] a lambda-expression. |
2323 | // |
2324 | // This is technically incorrect, there are some constant evaluated contexts |
2325 | // where this should be allowed. We should probably fix this when DR1607 is |
2326 | // ratified, it lays out the exact set of conditions where we shouldn't |
2327 | // allow a lambda-expression. |
2328 | case ExpressionEvaluationContext::ConstantEvaluated: |
2329 | case ExpressionEvaluationContext::ImmediateFunctionContext: |
2330 | // We don't actually diagnose this case immediately, because we |
2331 | // could be within a context where we might find out later that |
2332 | // the expression is potentially evaluated (e.g., for typeid). |
2333 | ExprEvalContexts.back().Lambdas.push_back(Elt: Lambda); |
2334 | break; |
2335 | |
2336 | case ExpressionEvaluationContext::DiscardedStatement: |
2337 | case ExpressionEvaluationContext::PotentiallyEvaluated: |
2338 | case ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed: |
2339 | break; |
2340 | } |
2341 | maybeAddDeclWithEffects(D: LSI->CallOperator); |
2342 | } |
2343 | |
2344 | return MaybeBindToTemporary(Lambda); |
2345 | } |
2346 | |
2347 | ExprResult Sema::BuildBlockForLambdaConversion(SourceLocation CurrentLocation, |
2348 | SourceLocation ConvLocation, |
2349 | CXXConversionDecl *Conv, |
2350 | Expr *Src) { |
2351 | // Make sure that the lambda call operator is marked used. |
2352 | CXXRecordDecl *Lambda = Conv->getParent(); |
2353 | CXXMethodDecl *CallOperator |
2354 | = cast<CXXMethodDecl>( |
2355 | Lambda->lookup( |
2356 | Context.DeclarationNames.getCXXOperatorName(Op: OO_Call)).front()); |
2357 | CallOperator->setReferenced(); |
2358 | CallOperator->markUsed(Context); |
2359 | |
2360 | ExprResult Init = PerformCopyInitialization( |
2361 | Entity: InitializedEntity::InitializeLambdaToBlock(BlockVarLoc: ConvLocation, Type: Src->getType()), |
2362 | EqualLoc: CurrentLocation, Init: Src); |
2363 | if (!Init.isInvalid()) |
2364 | Init = ActOnFinishFullExpr(Expr: Init.get(), /*DiscardedValue*/ false); |
2365 | |
2366 | if (Init.isInvalid()) |
2367 | return ExprError(); |
2368 | |
2369 | // Create the new block to be returned. |
2370 | BlockDecl *Block = BlockDecl::Create(C&: Context, DC: CurContext, L: ConvLocation); |
2371 | |
2372 | // Set the type information. |
2373 | Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo()); |
2374 | Block->setIsVariadic(CallOperator->isVariadic()); |
2375 | Block->setBlockMissingReturnType(false); |
2376 | |
2377 | // Add parameters. |
2378 | SmallVector<ParmVarDecl *, 4> BlockParams; |
2379 | for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) { |
2380 | ParmVarDecl *From = CallOperator->getParamDecl(I); |
2381 | BlockParams.push_back(Elt: ParmVarDecl::Create( |
2382 | C&: Context, DC: Block, StartLoc: From->getBeginLoc(), IdLoc: From->getLocation(), |
2383 | Id: From->getIdentifier(), T: From->getType(), TInfo: From->getTypeSourceInfo(), |
2384 | S: From->getStorageClass(), |
2385 | /*DefArg=*/nullptr)); |
2386 | } |
2387 | Block->setParams(BlockParams); |
2388 | |
2389 | Block->setIsConversionFromLambda(true); |
2390 | |
2391 | // Add capture. The capture uses a fake variable, which doesn't correspond |
2392 | // to any actual memory location. However, the initializer copy-initializes |
2393 | // the lambda object. |
2394 | TypeSourceInfo *CapVarTSI = |
2395 | Context.getTrivialTypeSourceInfo(T: Src->getType()); |
2396 | VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation, |
2397 | ConvLocation, nullptr, |
2398 | Src->getType(), CapVarTSI, |
2399 | SC_None); |
2400 | BlockDecl::Capture Capture(/*variable=*/CapVar, /*byRef=*/false, |
2401 | /*nested=*/false, /*copy=*/Init.get()); |
2402 | Block->setCaptures(Context, Captures: Capture, /*CapturesCXXThis=*/false); |
2403 | |
2404 | // Add a fake function body to the block. IR generation is responsible |
2405 | // for filling in the actual body, which cannot be expressed as an AST. |
2406 | Block->setBody(new (Context) CompoundStmt(ConvLocation)); |
2407 | |
2408 | // Create the block literal expression. |
2409 | // TODO: Do we ever get here if we have unexpanded packs in the lambda??? |
2410 | Expr *BuildBlock = |
2411 | new (Context) BlockExpr(Block, Conv->getConversionType(), |
2412 | /*ContainsUnexpandedParameterPack=*/false); |
2413 | ExprCleanupObjects.push_back(Elt: Block); |
2414 | Cleanup.setExprNeedsCleanups(true); |
2415 | |
2416 | return BuildBlock; |
2417 | } |
2418 | |
2419 | static FunctionDecl *getPatternFunctionDecl(FunctionDecl *FD) { |
2420 | if (FD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization) { |
2421 | while (FD->getInstantiatedFromMemberFunction()) |
2422 | FD = FD->getInstantiatedFromMemberFunction(); |
2423 | return FD; |
2424 | } |
2425 | |
2426 | if (FD->getTemplatedKind() == FunctionDecl::TK_DependentNonTemplate) |
2427 | return FD->getInstantiatedFromDecl(); |
2428 | |
2429 | FunctionTemplateDecl *FTD = FD->getPrimaryTemplate(); |
2430 | if (!FTD) |
2431 | return nullptr; |
2432 | |
2433 | while (FTD->getInstantiatedFromMemberTemplate()) |
2434 | FTD = FTD->getInstantiatedFromMemberTemplate(); |
2435 | |
2436 | return FTD->getTemplatedDecl(); |
2437 | } |
2438 | |
2439 | bool Sema::addInstantiatedCapturesToScope( |
2440 | FunctionDecl *Function, const FunctionDecl *PatternDecl, |
2441 | LocalInstantiationScope &Scope, |
2442 | const MultiLevelTemplateArgumentList &TemplateArgs) { |
2443 | const auto *LambdaClass = cast<CXXMethodDecl>(Val: Function)->getParent(); |
2444 | const auto *LambdaPattern = cast<CXXMethodDecl>(Val: PatternDecl)->getParent(); |
2445 | |
2446 | unsigned Instantiated = 0; |
2447 | |
2448 | // FIXME: This is a workaround for not having deferred lambda body |
2449 | // instantiation. |
2450 | // When transforming a lambda's body, if we encounter another call to a |
2451 | // nested lambda that contains a constraint expression, we add all of the |
2452 | // outer lambda's instantiated captures to the current instantiation scope to |
2453 | // facilitate constraint evaluation. However, these captures don't appear in |
2454 | // the CXXRecordDecl until after the lambda expression is rebuilt, so we |
2455 | // pull them out from the corresponding LSI. |
2456 | LambdaScopeInfo *InstantiatingScope = nullptr; |
2457 | if (LambdaPattern->capture_size() && !LambdaClass->capture_size()) { |
2458 | for (FunctionScopeInfo *Scope : llvm::reverse(C&: FunctionScopes)) { |
2459 | auto *LSI = dyn_cast<LambdaScopeInfo>(Val: Scope); |
2460 | if (!LSI || getPatternFunctionDecl(LSI->CallOperator) != PatternDecl) |
2461 | continue; |
2462 | InstantiatingScope = LSI; |
2463 | break; |
2464 | } |
2465 | assert(InstantiatingScope); |
2466 | } |
2467 | |
2468 | auto AddSingleCapture = [&](const ValueDecl *CapturedPattern, |
2469 | unsigned Index) { |
2470 | ValueDecl *CapturedVar = |
2471 | InstantiatingScope ? InstantiatingScope->Captures[Index].getVariable() |
2472 | : LambdaClass->getCapture(I: Index)->getCapturedVar(); |
2473 | assert(CapturedVar->isInitCapture()); |
2474 | Scope.InstantiatedLocal(CapturedPattern, CapturedVar); |
2475 | }; |
2476 | |
2477 | for (const LambdaCapture &CapturePattern : LambdaPattern->captures()) { |
2478 | if (!CapturePattern.capturesVariable()) { |
2479 | Instantiated++; |
2480 | continue; |
2481 | } |
2482 | ValueDecl *CapturedPattern = CapturePattern.getCapturedVar(); |
2483 | |
2484 | if (!CapturedPattern->isInitCapture()) { |
2485 | Instantiated++; |
2486 | continue; |
2487 | } |
2488 | |
2489 | if (!CapturedPattern->isParameterPack()) { |
2490 | AddSingleCapture(CapturedPattern, Instantiated++); |
2491 | } else { |
2492 | Scope.MakeInstantiatedLocalArgPack(CapturedPattern); |
2493 | SmallVector<UnexpandedParameterPack, 2> Unexpanded; |
2494 | SemaRef.collectUnexpandedParameterPacks( |
2495 | E: dyn_cast<VarDecl>(Val: CapturedPattern)->getInit(), Unexpanded); |
2496 | auto NumArgumentsInExpansion = |
2497 | getNumArgumentsInExpansionFromUnexpanded(Unexpanded, TemplateArgs); |
2498 | if (!NumArgumentsInExpansion) |
2499 | continue; |
2500 | for (unsigned Arg = 0; Arg < *NumArgumentsInExpansion; ++Arg) |
2501 | AddSingleCapture(CapturedPattern, Instantiated++); |
2502 | } |
2503 | } |
2504 | return false; |
2505 | } |
2506 | |
2507 | Sema::LambdaScopeForCallOperatorInstantiationRAII:: |
2508 | LambdaScopeForCallOperatorInstantiationRAII( |
2509 | Sema &SemaRef, FunctionDecl *FD, MultiLevelTemplateArgumentList MLTAL, |
2510 | LocalInstantiationScope &Scope, bool ShouldAddDeclsFromParentScope) |
2511 | : FunctionScopeRAII(SemaRef) { |
2512 | if (!isLambdaCallOperator(FD)) { |
2513 | FunctionScopeRAII::disable(); |
2514 | return; |
2515 | } |
2516 | |
2517 | SemaRef.RebuildLambdaScopeInfo(CallOperator: cast<CXXMethodDecl>(Val: FD)); |
2518 | |
2519 | FunctionDecl *FDPattern = getPatternFunctionDecl(FD); |
2520 | if (!FDPattern) |
2521 | return; |
2522 | |
2523 | if (!ShouldAddDeclsFromParentScope) |
2524 | return; |
2525 | |
2526 | llvm::SmallVector<std::pair<FunctionDecl *, FunctionDecl *>, 4> |
2527 | InstantiationAndPatterns; |
2528 | while (FDPattern && FD) { |
2529 | InstantiationAndPatterns.emplace_back(Args&: FDPattern, Args&: FD); |
2530 | |
2531 | FDPattern = |
2532 | dyn_cast<FunctionDecl>(Val: getLambdaAwareParentOfDeclContext(FDPattern)); |
2533 | FD = dyn_cast<FunctionDecl>(Val: getLambdaAwareParentOfDeclContext(FD)); |
2534 | } |
2535 | |
2536 | // Add instantiated parameters and local vars to scopes, starting from the |
2537 | // outermost lambda to the innermost lambda. This ordering ensures that |
2538 | // the outer instantiations can be found when referenced from within inner |
2539 | // lambdas. |
2540 | // |
2541 | // auto L = [](auto... x) { |
2542 | // return [](decltype(x)... y) { }; // Instantiating y needs x |
2543 | // }; |
2544 | // |
2545 | |
2546 | for (auto [FDPattern, FD] : llvm::reverse(C&: InstantiationAndPatterns)) { |
2547 | SemaRef.addInstantiatedParametersToScope(Function: FD, PatternDecl: FDPattern, Scope, TemplateArgs: MLTAL); |
2548 | SemaRef.addInstantiatedLocalVarsToScope(Function: FD, PatternDecl: FDPattern, Scope); |
2549 | |
2550 | if (isLambdaCallOperator(FD)) |
2551 | SemaRef.addInstantiatedCapturesToScope(Function: FD, PatternDecl: FDPattern, Scope, TemplateArgs: MLTAL); |
2552 | } |
2553 | } |
2554 |
Definitions
- getStackIndexOfNearestEnclosingCaptureReadyLambda
- getStackIndexOfNearestEnclosingCaptureCapableLambda
- getGenericLambdaTemplateParameterList
- createLambdaClosureType
- isInInlineFunction
- getCurrentMangleNumberContext
- buildTypeForLambdaCallOperator
- DiagnoseInvalidExplicitObjectParameterInLambda
- handleLambdaNumbering
- buildLambdaScopeReturnType
- buildLambdaScope
- finishLambdaExplicitCaptures
- ActOnLambdaExplicitTemplateParameterList
- findEnumForBlockReturn
- findEnumForBlockReturn
- findCommonEnumForBlockReturns
- adjustBlockReturnsToEnum
- deduceClosureReturnType
- buildLambdaInitCaptureInitialization
- createLambdaInitCaptureVarDecl
- addInitCapture
- getCurrentLambdaScopeUnsafe
- getDummyLambdaType
- getLambdaType
- CreateLambdaCallOperator
- AddTemplateParametersToLambdaCallOperator
- CompleteLambdaCallOperator
- ActOnLambdaExpressionAfterIntroducer
- ActOnLambdaClosureQualifiers
- ActOnLambdaClosureParameters
- ActOnStartOfLambdaDefinition
- ActOnLambdaError
- repeatForLambdaConversionFunctionCallingConvs
- getLambdaConversionFunctionCallConv
- getLambdaConversionFunctionResultType
- addFunctionPointerConversion
- addFunctionPointerConversions
- addBlockPointerConversion
- BuildCaptureInit
- ActOnLambdaExpr
- mapImplicitCaptureStyle
- CaptureHasSideEffects
- DiagnoseUnusedLambdaCapture
- BuildCaptureField
- ConstructFixItRangeForUnusedCapture
- BuildLambdaExpr
- BuildBlockForLambdaConversion
- getPatternFunctionDecl
- addInstantiatedCapturesToScope
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