1	//===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===//
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 the actions class which performs semantic analysis and
10	// builds an AST out of a parse stream.
11	//
12	//===----------------------------------------------------------------------===//
13
14	#include "UsedDeclVisitor.h"
15	#include "clang/AST/ASTContext.h"
16	#include "clang/AST/ASTDiagnostic.h"
17	#include "clang/AST/Decl.h"
18	#include "clang/AST/DeclCXX.h"
19	#include "clang/AST/DeclFriend.h"
20	#include "clang/AST/DeclObjC.h"
21	#include "clang/AST/Expr.h"
22	#include "clang/AST/ExprCXX.h"
23	#include "clang/AST/PrettyDeclStackTrace.h"
24	#include "clang/AST/StmtCXX.h"
25	#include "clang/AST/TypeOrdering.h"
26	#include "clang/Basic/DarwinSDKInfo.h"
27	#include "clang/Basic/DiagnosticOptions.h"
28	#include "clang/Basic/PartialDiagnostic.h"
29	#include "clang/Basic/SourceManager.h"
30	#include "clang/Basic/TargetInfo.h"
31	#include "clang/Lex/HeaderSearch.h"
32	#include "clang/Lex/HeaderSearchOptions.h"
33	#include "clang/Lex/Preprocessor.h"
34	#include "clang/Sema/CXXFieldCollector.h"
35	#include "clang/Sema/EnterExpressionEvaluationContext.h"
36	#include "clang/Sema/ExternalSemaSource.h"
37	#include "clang/Sema/Initialization.h"
38	#include "clang/Sema/MultiplexExternalSemaSource.h"
39	#include "clang/Sema/ObjCMethodList.h"
40	#include "clang/Sema/RISCVIntrinsicManager.h"
41	#include "clang/Sema/Scope.h"
42	#include "clang/Sema/ScopeInfo.h"
43	#include "clang/Sema/SemaAMDGPU.h"
44	#include "clang/Sema/SemaARM.h"
45	#include "clang/Sema/SemaAVR.h"
46	#include "clang/Sema/SemaBPF.h"
47	#include "clang/Sema/SemaCUDA.h"
48	#include "clang/Sema/SemaCodeCompletion.h"
49	#include "clang/Sema/SemaConsumer.h"
50	#include "clang/Sema/SemaDirectX.h"
51	#include "clang/Sema/SemaHLSL.h"
52	#include "clang/Sema/SemaHexagon.h"
53	#include "clang/Sema/SemaLoongArch.h"
54	#include "clang/Sema/SemaM68k.h"
55	#include "clang/Sema/SemaMIPS.h"
56	#include "clang/Sema/SemaMSP430.h"
57	#include "clang/Sema/SemaNVPTX.h"
58	#include "clang/Sema/SemaObjC.h"
59	#include "clang/Sema/SemaOpenACC.h"
60	#include "clang/Sema/SemaOpenCL.h"
61	#include "clang/Sema/SemaOpenMP.h"
62	#include "clang/Sema/SemaPPC.h"
63	#include "clang/Sema/SemaPseudoObject.h"
64	#include "clang/Sema/SemaRISCV.h"
65	#include "clang/Sema/SemaSPIRV.h"
66	#include "clang/Sema/SemaSYCL.h"
67	#include "clang/Sema/SemaSwift.h"
68	#include "clang/Sema/SemaSystemZ.h"
69	#include "clang/Sema/SemaWasm.h"
70	#include "clang/Sema/SemaX86.h"
71	#include "clang/Sema/TemplateDeduction.h"
72	#include "clang/Sema/TemplateInstCallback.h"
73	#include "clang/Sema/TypoCorrection.h"
74	#include "llvm/ADT/DenseMap.h"
75	#include "llvm/ADT/STLExtras.h"
76	#include "llvm/ADT/SmallPtrSet.h"
77	#include "llvm/Support/TimeProfiler.h"
78	#include <optional>
79
80	using namespace clang;
81	using namespace sema;
82
83	SourceLocation Sema::getLocForEndOfToken(SourceLocation Loc, unsigned Offset) {
84	return Lexer::getLocForEndOfToken(Loc, Offset, SM: SourceMgr, LangOpts);
85	}
86
87	SourceRange
88	Sema::getRangeForNextToken(SourceLocation Loc, bool IncludeMacros,
89	bool IncludeComments,
90	std::optional<tok::TokenKind> ExpectedToken) {
91	if (!Loc.isValid())
92	return SourceRange();
93	std::optional<Token> NextToken =
94	Lexer::findNextToken(Loc, SM: SourceMgr, LangOpts, IncludeComments);
95	if (!NextToken)
96	return SourceRange();
97	if (ExpectedToken && NextToken->getKind() != *ExpectedToken)
98	return SourceRange();
99	SourceLocation TokenStart = NextToken->getLocation();
100	SourceLocation TokenEnd = NextToken->getLastLoc();
101	if (!TokenStart.isValid() || !TokenEnd.isValid())
102	return SourceRange();
103	if (!IncludeMacros && (TokenStart.isMacroID() || TokenEnd.isMacroID()))
104	return SourceRange();
105
106	return SourceRange(TokenStart, TokenEnd);
107	}
108
109	ModuleLoader &Sema::getModuleLoader() const { return PP.getModuleLoader(); }
110
111	DarwinSDKInfo *
112	Sema::getDarwinSDKInfoForAvailabilityChecking(SourceLocation Loc,
113	StringRef Platform) {
114	auto *SDKInfo = getDarwinSDKInfoForAvailabilityChecking();
115	if (!SDKInfo && !WarnedDarwinSDKInfoMissing) {
116	Diag(Loc, diag::warn_missing_sdksettings_for_availability_checking)
117	<< Platform;
118	WarnedDarwinSDKInfoMissing = true;
119	}
120	return SDKInfo;
121	}
122
123	DarwinSDKInfo *Sema::getDarwinSDKInfoForAvailabilityChecking() {
124	if (CachedDarwinSDKInfo)
125	return CachedDarwinSDKInfo->get();
126	auto SDKInfo = parseDarwinSDKInfo(
127	VFS&: PP.getFileManager().getVirtualFileSystem(),
128	SDKRootPath: PP.getHeaderSearchInfo().getHeaderSearchOpts().Sysroot);
129	if (SDKInfo && *SDKInfo) {
130	CachedDarwinSDKInfo = std::make_unique<DarwinSDKInfo>(args: std::move(**SDKInfo));
131	return CachedDarwinSDKInfo->get();
132	}
133	if (!SDKInfo)
134	llvm::consumeError(Err: SDKInfo.takeError());
135	CachedDarwinSDKInfo = std::unique_ptr<DarwinSDKInfo>();
136	return nullptr;
137	}
138
139	IdentifierInfo *Sema::InventAbbreviatedTemplateParameterTypeName(
140	const IdentifierInfo *ParamName, unsigned int Index) {
141	std::string InventedName;
142	llvm::raw_string_ostream OS(InventedName);
143
144	if (!ParamName)
145	OS << "auto:" << Index + 1;
146	else
147	OS << ParamName->getName() << ":auto";
148
149	return &Context.Idents.get(Name: OS.str());
150	}
151
152	PrintingPolicy Sema::getPrintingPolicy(const ASTContext &Context,
153	const Preprocessor &PP) {
154	PrintingPolicy Policy = Context.getPrintingPolicy();
155	// In diagnostics, we print _Bool as bool if the latter is defined as the
156	// former.
157	Policy.Bool = Context.getLangOpts().Bool;
158	if (!Policy.Bool) {
159	if (const MacroInfo *BoolMacro = PP.getMacroInfo(II: Context.getBoolName())) {
160	Policy.Bool = BoolMacro->isObjectLike() &&
161	BoolMacro->getNumTokens() == 1 &&
162	BoolMacro->getReplacementToken(Tok: 0).is(K: tok::kw__Bool);
163	}
164	}
165
166	// Shorten the data output if needed
167	Policy.EntireContentsOfLargeArray = false;
168
169	return Policy;
170	}
171
172	void Sema::ActOnTranslationUnitScope(Scope *S) {
173	TUScope = S;
174	PushDeclContext(S, Context.getTranslationUnitDecl());
175	}
176
177	namespace clang {
178	namespace sema {
179
180	class SemaPPCallbacks : public PPCallbacks {
181	Sema *S = nullptr;
182	llvm::SmallVector<SourceLocation, 8> IncludeStack;
183	llvm::SmallVector<llvm::TimeTraceProfilerEntry *, 8> ProfilerStack;
184
185	public:
186	void set(Sema &S) { this->S = &S; }
187
188	void reset() { S = nullptr; }
189
190	void FileChanged(SourceLocation Loc, FileChangeReason Reason,
191	SrcMgr::CharacteristicKind FileType,
192	FileID PrevFID) override {
193	if (!S)
194	return;
195	switch (Reason) {
196	case EnterFile: {
197	SourceManager &SM = S->getSourceManager();
198	SourceLocation IncludeLoc = SM.getIncludeLoc(FID: SM.getFileID(SpellingLoc: Loc));
199	if (IncludeLoc.isValid()) {
200	if (llvm::timeTraceProfilerEnabled()) {
201	OptionalFileEntryRef FE = SM.getFileEntryRefForID(FID: SM.getFileID(SpellingLoc: Loc));
202	ProfilerStack.push_back(Elt: llvm::timeTraceAsyncProfilerBegin(
203	Name: "Source", Detail: FE ? FE->getName() : StringRef("<unknown>")));
204	}
205
206	IncludeStack.push_back(Elt: IncludeLoc);
207	S->DiagnoseNonDefaultPragmaAlignPack(
208	Kind: Sema::PragmaAlignPackDiagnoseKind::NonDefaultStateAtInclude,
209	IncludeLoc);
210	}
211	break;
212	}
213	case ExitFile:
214	if (!IncludeStack.empty()) {
215	if (llvm::timeTraceProfilerEnabled())
216	llvm::timeTraceProfilerEnd(E: ProfilerStack.pop_back_val());
217
218	S->DiagnoseNonDefaultPragmaAlignPack(
219	Kind: Sema::PragmaAlignPackDiagnoseKind::ChangedStateAtExit,
220	IncludeLoc: IncludeStack.pop_back_val());
221	}
222	break;
223	default:
224	break;
225	}
226	}
227	void PragmaDiagnostic(SourceLocation Loc, StringRef Namespace,
228	diag::Severity Mapping, StringRef Str) override {
229	// If one of the analysis-based diagnostics was enabled while processing
230	// a function, we want to note it in the analysis-based warnings so they
231	// can be run at the end of the function body even if the analysis warnings
232	// are disabled at that point.
233	SmallVector<diag::kind, 256> GroupDiags;
234	diag::Flavor Flavor =
235	Str[1] == 'W' ? diag::Flavor::WarningOrError : diag::Flavor::Remark;
236	StringRef Group = Str.substr(Start: 2);
237
238	if (S->PP.getDiagnostics().getDiagnosticIDs()->getDiagnosticsInGroup(
239	Flavor, Group, Diags&: GroupDiags))
240	return;
241
242	for (diag::kind K : GroupDiags) {
243	// Note: the cases in this switch should be kept in sync with the
244	// diagnostics in AnalysisBasedWarnings::getPolicyInEffectAt().
245	AnalysisBasedWarnings::Policy &Override =
246	S->AnalysisWarnings.getPolicyOverrides();
247	switch (K) {
248	default: break;
249	case diag::warn_unreachable:
250	case diag::warn_unreachable_break:
251	case diag::warn_unreachable_return:
252	case diag::warn_unreachable_loop_increment:
253	Override.enableCheckUnreachable = true;
254	break;
255	case diag::warn_double_lock:
256	Override.enableThreadSafetyAnalysis = true;
257	break;
258	case diag::warn_use_in_invalid_state:
259	Override.enableConsumedAnalysis = true;
260	break;
261	}
262	}
263	}
264	};
265
266	} // end namespace sema
267	} // end namespace clang
268
269	const unsigned Sema::MaxAlignmentExponent;
270	const uint64_t Sema::MaximumAlignment;
271
272	Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
273	TranslationUnitKind TUKind, CodeCompleteConsumer *CodeCompleter)
274	: SemaBase(*this), CollectStats(false), TUKind(TUKind),
275	CurFPFeatures(pp.getLangOpts()), LangOpts(pp.getLangOpts()), PP(pp),
276	Context(ctxt), Consumer(consumer), Diags(PP.getDiagnostics()),
277	SourceMgr(PP.getSourceManager()), APINotes(SourceMgr, LangOpts),
278	AnalysisWarnings(*this), ThreadSafetyDeclCache(nullptr),
279	LateTemplateParser(nullptr), LateTemplateParserCleanup(nullptr),
280	OpaqueParser(nullptr), CurContext(nullptr), ExternalSource(nullptr),
281	StackHandler(Diags), CurScope(nullptr), Ident_super(nullptr),
282	AMDGPUPtr(std::make_unique<SemaAMDGPU>(args&: *this)),
283	ARMPtr(std::make_unique<SemaARM>(args&: *this)),
284	AVRPtr(std::make_unique<SemaAVR>(args&: *this)),
285	BPFPtr(std::make_unique<SemaBPF>(args&: *this)),
286	CodeCompletionPtr(
287	std::make_unique<SemaCodeCompletion>(args&: *this, args&: CodeCompleter)),
288	CUDAPtr(std::make_unique<SemaCUDA>(args&: *this)),
289	DirectXPtr(std::make_unique<SemaDirectX>(args&: *this)),
290	HLSLPtr(std::make_unique<SemaHLSL>(args&: *this)),
291	HexagonPtr(std::make_unique<SemaHexagon>(args&: *this)),
292	LoongArchPtr(std::make_unique<SemaLoongArch>(args&: *this)),
293	M68kPtr(std::make_unique<SemaM68k>(args&: *this)),
294	MIPSPtr(std::make_unique<SemaMIPS>(args&: *this)),
295	MSP430Ptr(std::make_unique<SemaMSP430>(args&: *this)),
296	NVPTXPtr(std::make_unique<SemaNVPTX>(args&: *this)),
297	ObjCPtr(std::make_unique<SemaObjC>(args&: *this)),
298	OpenACCPtr(std::make_unique<SemaOpenACC>(args&: *this)),
299	OpenCLPtr(std::make_unique<SemaOpenCL>(args&: *this)),
300	OpenMPPtr(std::make_unique<SemaOpenMP>(args&: *this)),
301	PPCPtr(std::make_unique<SemaPPC>(args&: *this)),
302	PseudoObjectPtr(std::make_unique<SemaPseudoObject>(args&: *this)),
303	RISCVPtr(std::make_unique<SemaRISCV>(args&: *this)),
304	SPIRVPtr(std::make_unique<SemaSPIRV>(args&: *this)),
305	SYCLPtr(std::make_unique<SemaSYCL>(args&: *this)),
306	SwiftPtr(std::make_unique<SemaSwift>(args&: *this)),
307	SystemZPtr(std::make_unique<SemaSystemZ>(args&: *this)),
308	WasmPtr(std::make_unique<SemaWasm>(args&: *this)),
309	X86Ptr(std::make_unique<SemaX86>(args&: *this)),
310	MSPointerToMemberRepresentationMethod(
311	LangOpts.getMSPointerToMemberRepresentationMethod()),
312	MSStructPragmaOn(false), VtorDispStack(LangOpts.getVtorDispMode()),
313	AlignPackStack(AlignPackInfo(getLangOpts().XLPragmaPack)),
314	DataSegStack(nullptr), BSSSegStack(nullptr), ConstSegStack(nullptr),
315	CodeSegStack(nullptr), StrictGuardStackCheckStack(false),
316	FpPragmaStack(FPOptionsOverride()), CurInitSeg(nullptr),
317	VisContext(nullptr), PragmaAttributeCurrentTargetDecl(nullptr),
318	StdCoroutineTraitsCache(nullptr), IdResolver(pp),
319	OriginalLexicalContext(nullptr), StdInitializerList(nullptr),
320	StdTypeIdentity(nullptr),
321	FullyCheckedComparisonCategories(
322	static_cast<unsigned>(ComparisonCategoryType::Last) + 1),
323	StdSourceLocationImplDecl(nullptr), CXXTypeInfoDecl(nullptr),
324	GlobalNewDeleteDeclared(false), DisableTypoCorrection(false),
325	TyposCorrected(0), IsBuildingRecoveryCallExpr(false), NumSFINAEErrors(0),
326	AccessCheckingSFINAE(false), CurrentInstantiationScope(nullptr),
327	InNonInstantiationSFINAEContext(false), NonInstantiationEntries(0),
328	ArgPackSubstIndex(std::nullopt), SatisfactionCache(Context) {
329	assert(pp.TUKind == TUKind);
330	TUScope = nullptr;
331
332	LoadedExternalKnownNamespaces = false;
333	for (unsigned I = 0; I != NSAPI::NumNSNumberLiteralMethods; ++I)
334	ObjC().NSNumberLiteralMethods[I] = nullptr;
335
336	if (getLangOpts().ObjC)
337	ObjC().NSAPIObj.reset(p: new NSAPI(Context));
338
339	if (getLangOpts().CPlusPlus)
340	FieldCollector.reset(p: new CXXFieldCollector());
341
342	// Tell diagnostics how to render things from the AST library.
343	Diags.SetArgToStringFn(Fn: &FormatASTNodeDiagnosticArgument, Cookie: &Context);
344
345	// This evaluation context exists to ensure that there's always at least one
346	// valid evaluation context available. It is never removed from the
347	// evaluation stack.
348	ExprEvalContexts.emplace_back(
349	Args: ExpressionEvaluationContext::PotentiallyEvaluated, Args: 0, Args: CleanupInfo{},
350	Args: nullptr, Args: ExpressionEvaluationContextRecord::EK_Other);
351
352	// Initialization of data sharing attributes stack for OpenMP
353	OpenMP().InitDataSharingAttributesStack();
354
355	std::unique_ptr<sema::SemaPPCallbacks> Callbacks =
356	std::make_unique<sema::SemaPPCallbacks>();
357	SemaPPCallbackHandler = Callbacks.get();
358	PP.addPPCallbacks(C: std::move(Callbacks));
359	SemaPPCallbackHandler->set(*this);
360
361	CurFPFeatures.setFPEvalMethod(PP.getCurrentFPEvalMethod());
362	}
363
364	// Anchor Sema's type info to this TU.
365	void Sema::anchor() {}
366
367	void Sema::addImplicitTypedef(StringRef Name, QualType T) {
368	DeclarationName DN = &Context.Idents.get(Name);
369	if (IdResolver.begin(Name: DN) == IdResolver.end())
370	PushOnScopeChains(Context.buildImplicitTypedef(T, Name), TUScope);
371	}
372
373	void Sema::Initialize() {
374	// Create BuiltinVaListDecl *before* ExternalSemaSource::InitializeSema(this)
375	// because during initialization ASTReader can emit globals that require
376	// name mangling. And the name mangling uses BuiltinVaListDecl.
377	if (Context.getTargetInfo().hasBuiltinMSVaList())
378	(void)Context.getBuiltinMSVaListDecl();
379	(void)Context.getBuiltinVaListDecl();
380
381	if (SemaConsumer *SC = dyn_cast<SemaConsumer>(Val: &Consumer))
382	SC->InitializeSema(S&: *this);
383
384	// Tell the external Sema source about this Sema object.
385	if (ExternalSemaSource *ExternalSema
386	= dyn_cast_or_null<ExternalSemaSource>(Val: Context.getExternalSource()))
387	ExternalSema->InitializeSema(S&: *this);
388
389	// This needs to happen after ExternalSemaSource::InitializeSema(this) or we
390	// will not be able to merge any duplicate __va_list_tag decls correctly.
391	VAListTagName = PP.getIdentifierInfo(Name: "__va_list_tag");
392
393	if (!TUScope)
394	return;
395
396	// Initialize predefined 128-bit integer types, if needed.
397	if (Context.getTargetInfo().hasInt128Type() ||
398	(Context.getAuxTargetInfo() &&
399	Context.getAuxTargetInfo()->hasInt128Type())) {
400	// If either of the 128-bit integer types are unavailable to name lookup,
401	// define them now.
402	DeclarationName Int128 = &Context.Idents.get(Name: "__int128_t");
403	if (IdResolver.begin(Name: Int128) == IdResolver.end())
404	PushOnScopeChains(Context.getInt128Decl(), TUScope);
405
406	DeclarationName UInt128 = &Context.Idents.get(Name: "__uint128_t");
407	if (IdResolver.begin(Name: UInt128) == IdResolver.end())
408	PushOnScopeChains(Context.getUInt128Decl(), TUScope);
409	}
410
411
412	// Initialize predefined Objective-C types:
413	if (getLangOpts().ObjC) {
414	// If 'SEL' does not yet refer to any declarations, make it refer to the
415	// predefined 'SEL'.
416	DeclarationName SEL = &Context.Idents.get(Name: "SEL");
417	if (IdResolver.begin(Name: SEL) == IdResolver.end())
418	PushOnScopeChains(Context.getObjCSelDecl(), TUScope);
419
420	// If 'id' does not yet refer to any declarations, make it refer to the
421	// predefined 'id'.
422	DeclarationName Id = &Context.Idents.get(Name: "id");
423	if (IdResolver.begin(Name: Id) == IdResolver.end())
424	PushOnScopeChains(Context.getObjCIdDecl(), TUScope);
425
426	// Create the built-in typedef for 'Class'.
427	DeclarationName Class = &Context.Idents.get(Name: "Class");
428	if (IdResolver.begin(Name: Class) == IdResolver.end())
429	PushOnScopeChains(Context.getObjCClassDecl(), TUScope);
430
431	// Create the built-in forward declaratino for 'Protocol'.
432	DeclarationName Protocol = &Context.Idents.get(Name: "Protocol");
433	if (IdResolver.begin(Name: Protocol) == IdResolver.end())
434	PushOnScopeChains(Context.getObjCProtocolDecl(), TUScope);
435	}
436
437	// Create the internal type for the *StringMakeConstantString builtins.
438	DeclarationName ConstantString = &Context.Idents.get(Name: "__NSConstantString");
439	if (IdResolver.begin(Name: ConstantString) == IdResolver.end())
440	PushOnScopeChains(Context.getCFConstantStringDecl(), TUScope);
441
442	// Initialize Microsoft "predefined C++ types".
443	if (getLangOpts().MSVCCompat) {
444	if (getLangOpts().CPlusPlus &&
445	IdResolver.begin(Name: &Context.Idents.get(Name: "type_info")) == IdResolver.end())
446	PushOnScopeChains(
447	Context.buildImplicitRecord(Name: "type_info", TK: TagTypeKind::Class),
448	TUScope);
449
450	addImplicitTypedef(Name: "size_t", T: Context.getSizeType());
451	}
452
453	// Initialize predefined OpenCL types and supported extensions and (optional)
454	// core features.
455	if (getLangOpts().OpenCL) {
456	getOpenCLOptions().addSupport(
457	FeaturesMap: Context.getTargetInfo().getSupportedOpenCLOpts(), Opts: getLangOpts());
458	addImplicitTypedef(Name: "sampler_t", T: Context.OCLSamplerTy);
459	addImplicitTypedef(Name: "event_t", T: Context.OCLEventTy);
460	auto OCLCompatibleVersion = getLangOpts().getOpenCLCompatibleVersion();
461	if (OCLCompatibleVersion >= 200) {
462	if (getLangOpts().OpenCLCPlusPlus || getLangOpts().Blocks) {
463	addImplicitTypedef(Name: "clk_event_t", T: Context.OCLClkEventTy);
464	addImplicitTypedef(Name: "queue_t", T: Context.OCLQueueTy);
465	}
466	if (getLangOpts().OpenCLPipes)
467	addImplicitTypedef(Name: "reserve_id_t", T: Context.OCLReserveIDTy);
468	addImplicitTypedef(Name: "atomic_int", T: Context.getAtomicType(T: Context.IntTy));
469	addImplicitTypedef(Name: "atomic_uint",
470	T: Context.getAtomicType(T: Context.UnsignedIntTy));
471	addImplicitTypedef(Name: "atomic_float",
472	T: Context.getAtomicType(T: Context.FloatTy));
473	// OpenCLC v2.0, s6.13.11.6 requires that atomic_flag is implemented as
474	// 32-bit integer and OpenCLC v2.0, s6.1.1 int is always 32-bit wide.
475	addImplicitTypedef(Name: "atomic_flag", T: Context.getAtomicType(T: Context.IntTy));
476
477
478	// OpenCL v2.0 s6.13.11.6:
479	// - The atomic_long and atomic_ulong types are supported if the
480	// cl_khr_int64_base_atomics and cl_khr_int64_extended_atomics
481	// extensions are supported.
482	// - The atomic_double type is only supported if double precision
483	// is supported and the cl_khr_int64_base_atomics and
484	// cl_khr_int64_extended_atomics extensions are supported.
485	// - If the device address space is 64-bits, the data types
486	// atomic_intptr_t, atomic_uintptr_t, atomic_size_t and
487	// atomic_ptrdiff_t are supported if the cl_khr_int64_base_atomics and
488	// cl_khr_int64_extended_atomics extensions are supported.
489
490	auto AddPointerSizeDependentTypes = [&]() {
491	auto AtomicSizeT = Context.getAtomicType(T: Context.getSizeType());
492	auto AtomicIntPtrT = Context.getAtomicType(T: Context.getIntPtrType());
493	auto AtomicUIntPtrT = Context.getAtomicType(T: Context.getUIntPtrType());
494	auto AtomicPtrDiffT =
495	Context.getAtomicType(T: Context.getPointerDiffType());
496	addImplicitTypedef(Name: "atomic_size_t", T: AtomicSizeT);
497	addImplicitTypedef(Name: "atomic_intptr_t", T: AtomicIntPtrT);
498	addImplicitTypedef(Name: "atomic_uintptr_t", T: AtomicUIntPtrT);
499	addImplicitTypedef(Name: "atomic_ptrdiff_t", T: AtomicPtrDiffT);
500	};
501
502	if (Context.getTypeSize(T: Context.getSizeType()) == 32) {
503	AddPointerSizeDependentTypes();
504	}
505
506	if (getOpenCLOptions().isSupported(Ext: "cl_khr_fp16", LO: getLangOpts())) {
507	auto AtomicHalfT = Context.getAtomicType(T: Context.HalfTy);
508	addImplicitTypedef(Name: "atomic_half", T: AtomicHalfT);
509	}
510
511	std::vector<QualType> Atomic64BitTypes;
512	if (getOpenCLOptions().isSupported(Ext: "cl_khr_int64_base_atomics",
513	LO: getLangOpts()) &&
514	getOpenCLOptions().isSupported(Ext: "cl_khr_int64_extended_atomics",
515	LO: getLangOpts())) {
516	if (getOpenCLOptions().isSupported(Ext: "cl_khr_fp64", LO: getLangOpts())) {
517	auto AtomicDoubleT = Context.getAtomicType(T: Context.DoubleTy);
518	addImplicitTypedef(Name: "atomic_double", T: AtomicDoubleT);
519	Atomic64BitTypes.push_back(AtomicDoubleT);
520	}
521	auto AtomicLongT = Context.getAtomicType(T: Context.LongTy);
522	auto AtomicULongT = Context.getAtomicType(T: Context.UnsignedLongTy);
523	addImplicitTypedef(Name: "atomic_long", T: AtomicLongT);
524	addImplicitTypedef(Name: "atomic_ulong", T: AtomicULongT);
525
526
527	if (Context.getTypeSize(T: Context.getSizeType()) == 64) {
528	AddPointerSizeDependentTypes();
529	}
530	}
531	}
532
533	#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
534	if (getOpenCLOptions().isSupported(#Ext, getLangOpts())) { \
535	addImplicitTypedef(#ExtType, Context.Id##Ty); \
536	}
537	#include "clang/Basic/OpenCLExtensionTypes.def"
538	}
539
540	if (Context.getTargetInfo().hasAArch64ACLETypes() ||
541	(Context.getAuxTargetInfo() &&
542	Context.getAuxTargetInfo()->hasAArch64ACLETypes())) {
543	#define SVE_TYPE(Name, Id, SingletonId) \
544	addImplicitTypedef(#Name, Context.SingletonId);
545	#define NEON_VECTOR_TYPE(Name, BaseType, ElBits, NumEls, VectorKind) \
546	addImplicitTypedef( \
547	#Name, Context.getVectorType(Context.BaseType, NumEls, VectorKind));
548	#include "clang/Basic/AArch64ACLETypes.def"
549	}
550
551	if (Context.getTargetInfo().getTriple().isPPC64()) {
552	#define PPC_VECTOR_MMA_TYPE(Name, Id, Size) \
553	addImplicitTypedef(#Name, Context.Id##Ty);
554	#include "clang/Basic/PPCTypes.def"
555	#define PPC_VECTOR_VSX_TYPE(Name, Id, Size) \
556	addImplicitTypedef(#Name, Context.Id##Ty);
557	#include "clang/Basic/PPCTypes.def"
558	}
559
560	if (Context.getTargetInfo().hasRISCVVTypes()) {
561	#define RVV_TYPE(Name, Id, SingletonId) \
562	addImplicitTypedef(Name, Context.SingletonId);
563	#include "clang/Basic/RISCVVTypes.def"
564	}
565
566	if (Context.getTargetInfo().getTriple().isWasm() &&
567	Context.getTargetInfo().hasFeature(Feature: "reference-types")) {
568	#define WASM_TYPE(Name, Id, SingletonId) \
569	addImplicitTypedef(Name, Context.SingletonId);
570	#include "clang/Basic/WebAssemblyReferenceTypes.def"
571	}
572
573	if (Context.getTargetInfo().getTriple().isAMDGPU() ||
574	(Context.getAuxTargetInfo() &&
575	Context.getAuxTargetInfo()->getTriple().isAMDGPU())) {
576	#define AMDGPU_TYPE(Name, Id, SingletonId, Width, Align) \
577	addImplicitTypedef(Name, Context.SingletonId);
578	#include "clang/Basic/AMDGPUTypes.def"
579	}
580
581	if (Context.getTargetInfo().hasBuiltinMSVaList()) {
582	DeclarationName MSVaList = &Context.Idents.get(Name: "__builtin_ms_va_list");
583	if (IdResolver.begin(Name: MSVaList) == IdResolver.end())
584	PushOnScopeChains(Context.getBuiltinMSVaListDecl(), TUScope);
585	}
586
587	DeclarationName BuiltinVaList = &Context.Idents.get(Name: "__builtin_va_list");
588	if (IdResolver.begin(Name: BuiltinVaList) == IdResolver.end())
589	PushOnScopeChains(Context.getBuiltinVaListDecl(), TUScope);
590	}
591
592	Sema::~Sema() {
593	assert(InstantiatingSpecializations.empty() &&
594	"failed to clean up an InstantiatingTemplate?");
595
596	if (VisContext) FreeVisContext();
597
598	// Kill all the active scopes.
599	for (sema::FunctionScopeInfo *FSI : FunctionScopes)
600	delete FSI;
601
602	// Tell the SemaConsumer to forget about us; we're going out of scope.
603	if (SemaConsumer *SC = dyn_cast<SemaConsumer>(Val: &Consumer))
604	SC->ForgetSema();
605
606	// Detach from the external Sema source.
607	if (ExternalSemaSource *ExternalSema
608	= dyn_cast_or_null<ExternalSemaSource>(Val: Context.getExternalSource()))
609	ExternalSema->ForgetSema();
610
611	// Delete cached satisfactions.
612	std::vector<ConstraintSatisfaction *> Satisfactions;
613	Satisfactions.reserve(n: SatisfactionCache.size());
614	for (auto &Node : SatisfactionCache)
615	Satisfactions.push_back(x: &Node);
616	for (auto *Node : Satisfactions)
617	delete Node;
618
619	threadSafety::threadSafetyCleanup(Cache: ThreadSafetyDeclCache);
620
621	// Destroys data sharing attributes stack for OpenMP
622	OpenMP().DestroyDataSharingAttributesStack();
623
624	// Detach from the PP callback handler which outlives Sema since it's owned
625	// by the preprocessor.
626	SemaPPCallbackHandler->reset();
627	}
628
629	void Sema::runWithSufficientStackSpace(SourceLocation Loc,
630	llvm::function_ref<void()> Fn) {
631	StackHandler.runWithSufficientStackSpace(Loc, Fn);
632	}
633
634	bool Sema::makeUnavailableInSystemHeader(SourceLocation loc,
635	UnavailableAttr::ImplicitReason reason) {
636	// If we're not in a function, it's an error.
637	FunctionDecl *fn = dyn_cast<FunctionDecl>(Val: CurContext);
638	if (!fn) return false;
639
640	// If we're in template instantiation, it's an error.
641	if (inTemplateInstantiation())
642	return false;
643
644	// If that function's not in a system header, it's an error.
645	if (!Context.getSourceManager().isInSystemHeader(Loc: loc))
646	return false;
647
648	// If the function is already unavailable, it's not an error.
649	if (fn->hasAttr<UnavailableAttr>()) return true;
650
651	fn->addAttr(UnavailableAttr::CreateImplicit(Context, "", reason, loc));
652	return true;
653	}
654
655	ASTMutationListener *Sema::getASTMutationListener() const {
656	return getASTConsumer().GetASTMutationListener();
657	}
658
659	void Sema::addExternalSource(ExternalSemaSource *E) {
660	assert(E && "Cannot use with NULL ptr");
661
662	if (!ExternalSource) {
663	ExternalSource = E;
664	return;
665	}
666
667	if (auto *Ex = dyn_cast<MultiplexExternalSemaSource>(Val&: ExternalSource))
668	Ex->AddSource(Source: E);
669	else
670	ExternalSource = new MultiplexExternalSemaSource(ExternalSource.get(), E);
671	}
672
673	void Sema::PrintStats() const {
674	llvm::errs() << "\n*** Semantic Analysis Stats:\n";
675	llvm::errs() << NumSFINAEErrors << " SFINAE diagnostics trapped.\n";
676
677	BumpAlloc.PrintStats();
678	AnalysisWarnings.PrintStats();
679	}
680
681	void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
682	QualType SrcType,
683	SourceLocation Loc) {
684	std::optional<NullabilityKind> ExprNullability = SrcType->getNullability();
685	if (!ExprNullability || (*ExprNullability != NullabilityKind::Nullable &&
686	*ExprNullability != NullabilityKind::NullableResult))
687	return;
688
689	std::optional<NullabilityKind> TypeNullability = DstType->getNullability();
690	if (!TypeNullability || *TypeNullability != NullabilityKind::NonNull)
691	return;
692
693	Diag(Loc, diag::warn_nullability_lost) << SrcType << DstType;
694	}
695
696	// Generate diagnostics when adding or removing effects in a type conversion.
697	void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
698	SourceLocation Loc) {
699	const auto SrcFX = FunctionEffectsRef::get(QT: SrcType);
700	const auto DstFX = FunctionEffectsRef::get(QT: DstType);
701	if (SrcFX != DstFX) {
702	for (const auto &Diff : FunctionEffectDiffVector(SrcFX, DstFX)) {
703	if (Diff.shouldDiagnoseConversion(SrcType, SrcFX, DstType, DstFX))
704	Diag(Loc, diag::warn_invalid_add_func_effects) << Diff.effectName();
705	}
706	}
707	}
708
709	void Sema::diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E) {
710	// nullptr only exists from C++11 on, so don't warn on its absence earlier.
711	if (!getLangOpts().CPlusPlus11)
712	return;
713
714	if (Kind != CK_NullToPointer && Kind != CK_NullToMemberPointer)
715	return;
716
717	const Expr *EStripped = E->IgnoreParenImpCasts();
718	if (EStripped->getType()->isNullPtrType())
719	return;
720	if (isa<GNUNullExpr>(Val: EStripped))
721	return;
722
723	if (Diags.isIgnored(diag::warn_zero_as_null_pointer_constant,
724	E->getBeginLoc()))
725	return;
726
727	// Don't diagnose the conversion from a 0 literal to a null pointer argument
728	// in a synthesized call to operator<=>.
729	if (!CodeSynthesisContexts.empty() &&
730	CodeSynthesisContexts.back().Kind ==
731	CodeSynthesisContext::RewritingOperatorAsSpaceship)
732	return;
733
734	// Ignore null pointers in defaulted comparison operators.
735	FunctionDecl *FD = getCurFunctionDecl();
736	if (FD && FD->isDefaulted()) {
737	return;
738	}
739
740	// If it is a macro from system header, and if the macro name is not "NULL",
741	// do not warn.
742	// Note that uses of "NULL" will be ignored above on systems that define it
743	// as __null.
744	SourceLocation MaybeMacroLoc = E->getBeginLoc();
745	if (Diags.getSuppressSystemWarnings() &&
746	SourceMgr.isInSystemMacro(loc: MaybeMacroLoc) &&
747	!findMacroSpelling(loc&: MaybeMacroLoc, name: "NULL"))
748	return;
749
750	Diag(E->getBeginLoc(), diag::warn_zero_as_null_pointer_constant)
751	<< FixItHint::CreateReplacement(E->getSourceRange(), "nullptr");
752	}
753
754	/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
755	/// If there is already an implicit cast, merge into the existing one.
756	/// The result is of the given category.
757	ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
758	CastKind Kind, ExprValueKind VK,
759	const CXXCastPath *BasePath,
760	CheckedConversionKind CCK) {
761	#ifndef NDEBUG
762	if (VK == VK_PRValue && !E->isPRValue()) {
763	switch (Kind) {
764	default:
765	llvm_unreachable(
766	("can't implicitly cast glvalue to prvalue with this cast "
767	"kind: " +
768	std::string(CastExpr::getCastKindName(Kind)))
769	.c_str());
770	case CK_Dependent:
771	case CK_LValueToRValue:
772	case CK_ArrayToPointerDecay:
773	case CK_FunctionToPointerDecay:
774	case CK_ToVoid:
775	case CK_NonAtomicToAtomic:
776	case CK_HLSLArrayRValue:
777	case CK_HLSLAggregateSplatCast:
778	break;
779	}
780	}
781	assert((VK == VK_PRValue || Kind == CK_Dependent || !E->isPRValue()) &&
782	"can't cast prvalue to glvalue");
783	#endif
784
785	diagnoseNullableToNonnullConversion(DstType: Ty, SrcType: E->getType(), Loc: E->getBeginLoc());
786	diagnoseZeroToNullptrConversion(Kind, E);
787	if (Context.hasAnyFunctionEffects() && !isCast(CCK) &&
788	Kind != CK_NullToPointer && Kind != CK_NullToMemberPointer)
789	diagnoseFunctionEffectConversion(DstType: Ty, SrcType: E->getType(), Loc: E->getBeginLoc());
790
791	QualType ExprTy = Context.getCanonicalType(T: E->getType());
792	QualType TypeTy = Context.getCanonicalType(T: Ty);
793
794	// This cast is used in place of a regular LValue to RValue cast for
795	// HLSL Array Parameter Types. It needs to be emitted even if
796	// ExprTy == TypeTy, except if E is an HLSLOutArgExpr
797	// Emitting a cast in that case will prevent HLSLOutArgExpr from
798	// being handled properly in EmitCallArg
799	if (Kind == CK_HLSLArrayRValue && !isa<HLSLOutArgExpr>(Val: E))
800	return ImplicitCastExpr::Create(Context, T: Ty, Kind, Operand: E, BasePath, Cat: VK,
801	FPO: CurFPFeatureOverrides());
802
803	if (ExprTy == TypeTy)
804	return E;
805
806	if (Kind == CK_ArrayToPointerDecay) {
807	// C++1z [conv.array]: The temporary materialization conversion is applied.
808	// We also use this to fuel C++ DR1213, which applies to C++11 onwards.
809	if (getLangOpts().CPlusPlus && E->isPRValue()) {
810	// The temporary is an lvalue in C++98 and an xvalue otherwise.
811	ExprResult Materialized = CreateMaterializeTemporaryExpr(
812	T: E->getType(), Temporary: E, BoundToLvalueReference: !getLangOpts().CPlusPlus11);
813	if (Materialized.isInvalid())
814	return ExprError();
815	E = Materialized.get();
816	}
817	// C17 6.7.1p6 footnote 124: The implementation can treat any register
818	// declaration simply as an auto declaration. However, whether or not
819	// addressable storage is actually used, the address of any part of an
820	// object declared with storage-class specifier register cannot be
821	// computed, either explicitly(by use of the unary & operator as discussed
822	// in 6.5.3.2) or implicitly(by converting an array name to a pointer as
823	// discussed in 6.3.2.1).Thus, the only operator that can be applied to an
824	// array declared with storage-class specifier register is sizeof.
825	if (VK == VK_PRValue && !getLangOpts().CPlusPlus && !E->isPRValue()) {
826	if (const auto *DRE = dyn_cast<DeclRefExpr>(Val: E)) {
827	if (const auto *VD = dyn_cast<VarDecl>(Val: DRE->getDecl())) {
828	if (VD->getStorageClass() == SC_Register) {
829	Diag(E->getExprLoc(), diag::err_typecheck_address_of)
830	<< /*register variable*/ 3 << E->getSourceRange();
831	return ExprError();
832	}
833	}
834	}
835	}
836	}
837
838	if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(Val: E)) {
839	if (ImpCast->getCastKind() == Kind && (!BasePath || BasePath->empty())) {
840	ImpCast->setType(Ty);
841	ImpCast->setValueKind(VK);
842	return E;
843	}
844	}
845
846	return ImplicitCastExpr::Create(Context, T: Ty, Kind, Operand: E, BasePath, Cat: VK,
847	FPO: CurFPFeatureOverrides());
848	}
849
850	CastKind Sema::ScalarTypeToBooleanCastKind(QualType ScalarTy) {
851	switch (ScalarTy->getScalarTypeKind()) {
852	case Type::STK_Bool: return CK_NoOp;
853	case Type::STK_CPointer: return CK_PointerToBoolean;
854	case Type::STK_BlockPointer: return CK_PointerToBoolean;
855	case Type::STK_ObjCObjectPointer: return CK_PointerToBoolean;
856	case Type::STK_MemberPointer: return CK_MemberPointerToBoolean;
857	case Type::STK_Integral: return CK_IntegralToBoolean;
858	case Type::STK_Floating: return CK_FloatingToBoolean;
859	case Type::STK_IntegralComplex: return CK_IntegralComplexToBoolean;
860	case Type::STK_FloatingComplex: return CK_FloatingComplexToBoolean;
861	case Type::STK_FixedPoint: return CK_FixedPointToBoolean;
862	}
863	llvm_unreachable("unknown scalar type kind");
864	}
865
866	/// Used to prune the decls of Sema's UnusedFileScopedDecls vector.
867	static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
868	if (D->getMostRecentDecl()->isUsed())
869	return true;
870
871	if (D->isExternallyVisible())
872	return true;
873
874	if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: D)) {
875	// If this is a function template and none of its specializations is used,
876	// we should warn.
877	if (FunctionTemplateDecl *Template = FD->getDescribedFunctionTemplate())
878	for (const auto *Spec : Template->specializations())
879	if (ShouldRemoveFromUnused(SemaRef, Spec))
880	return true;
881
882	// UnusedFileScopedDecls stores the first declaration.
883	// The declaration may have become definition so check again.
884	const FunctionDecl *DeclToCheck;
885	if (FD->hasBody(Definition&: DeclToCheck))
886	return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
887
888	// Later redecls may add new information resulting in not having to warn,
889	// so check again.
890	DeclToCheck = FD->getMostRecentDecl();
891	if (DeclToCheck != FD)
892	return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
893	}
894
895	if (const VarDecl *VD = dyn_cast<VarDecl>(Val: D)) {
896	// If a variable usable in constant expressions is referenced,
897	// don't warn if it isn't used: if the value of a variable is required
898	// for the computation of a constant expression, it doesn't make sense to
899	// warn even if the variable isn't odr-used. (isReferenced doesn't
900	// precisely reflect that, but it's a decent approximation.)
901	if (VD->isReferenced() &&
902	VD->mightBeUsableInConstantExpressions(C: SemaRef->Context))
903	return true;
904
905	if (VarTemplateDecl *Template = VD->getDescribedVarTemplate())
906	// If this is a variable template and none of its specializations is used,
907	// we should warn.
908	for (const auto *Spec : Template->specializations())
909	if (ShouldRemoveFromUnused(SemaRef, Spec))
910	return true;
911
912	// UnusedFileScopedDecls stores the first declaration.
913	// The declaration may have become definition so check again.
914	const VarDecl *DeclToCheck = VD->getDefinition();
915	if (DeclToCheck)
916	return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
917
918	// Later redecls may add new information resulting in not having to warn,
919	// so check again.
920	DeclToCheck = VD->getMostRecentDecl();
921	if (DeclToCheck != VD)
922	return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
923	}
924
925	return false;
926	}
927
928	static bool isFunctionOrVarDeclExternC(const NamedDecl *ND) {
929	if (const auto *FD = dyn_cast<FunctionDecl>(Val: ND))
930	return FD->isExternC();
931	return cast<VarDecl>(Val: ND)->isExternC();
932	}
933
934	/// Determine whether ND is an external-linkage function or variable whose
935	/// type has no linkage.
936	bool Sema::isExternalWithNoLinkageType(const ValueDecl *VD) const {
937	// Note: it's not quite enough to check whether VD has UniqueExternalLinkage,
938	// because we also want to catch the case where its type has VisibleNoLinkage,
939	// which does not affect the linkage of VD.
940	return getLangOpts().CPlusPlus && VD->hasExternalFormalLinkage() &&
941	!isExternalFormalLinkage(L: VD->getType()->getLinkage()) &&
942	!isFunctionOrVarDeclExternC(VD);
943	}
944
945	/// Obtains a sorted list of functions and variables that are undefined but
946	/// ODR-used.
947	void Sema::getUndefinedButUsed(
948	SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> > &Undefined) {
949	for (const auto &UndefinedUse : UndefinedButUsed) {
950	NamedDecl *ND = UndefinedUse.first;
951
952	// Ignore attributes that have become invalid.
953	if (ND->isInvalidDecl()) continue;
954
955	// __attribute__((weakref)) is basically a definition.
956	if (ND->hasAttr<WeakRefAttr>()) continue;
957
958	if (isa<CXXDeductionGuideDecl>(Val: ND))
959	continue;
960
961	if (ND->hasAttr<DLLImportAttr>() || ND->hasAttr<DLLExportAttr>()) {
962	// An exported function will always be emitted when defined, so even if
963	// the function is inline, it doesn't have to be emitted in this TU. An
964	// imported function implies that it has been exported somewhere else.
965	continue;
966	}
967
968	if (const auto *FD = dyn_cast<FunctionDecl>(Val: ND)) {
969	if (FD->isDefined())
970	continue;
971	if (FD->isExternallyVisible() &&
972	!isExternalWithNoLinkageType(FD) &&
973	!FD->getMostRecentDecl()->isInlined() &&
974	!FD->hasAttr<ExcludeFromExplicitInstantiationAttr>())
975	continue;
976	if (FD->getBuiltinID())
977	continue;
978	} else {
979	const auto *VD = cast<VarDecl>(Val: ND);
980	if (VD->hasDefinition() != VarDecl::DeclarationOnly)
981	continue;
982	if (VD->isExternallyVisible() &&
983	!isExternalWithNoLinkageType(VD) &&
984	!VD->getMostRecentDecl()->isInline() &&
985	!VD->hasAttr<ExcludeFromExplicitInstantiationAttr>())
986	continue;
987
988	// Skip VarDecls that lack formal definitions but which we know are in
989	// fact defined somewhere.
990	if (VD->isKnownToBeDefined())
991	continue;
992	}
993
994	Undefined.push_back(Elt: std::make_pair(x&: ND, y: UndefinedUse.second));
995	}
996	}
997
998	/// checkUndefinedButUsed - Check for undefined objects with internal linkage
999	/// or that are inline.
1000	static void checkUndefinedButUsed(Sema &S) {
1001	if (S.UndefinedButUsed.empty()) return;
1002
1003	// Collect all the still-undefined entities with internal linkage.
1004	SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
1005	S.getUndefinedButUsed(Undefined);
1006	S.UndefinedButUsed.clear();
1007	if (Undefined.empty()) return;
1008
1009	for (const auto &Undef : Undefined) {
1010	ValueDecl *VD = cast<ValueDecl>(Val: Undef.first);
1011	SourceLocation UseLoc = Undef.second;
1012
1013	if (S.isExternalWithNoLinkageType(VD)) {
1014	// C++ [basic.link]p8:
1015	// A type without linkage shall not be used as the type of a variable
1016	// or function with external linkage unless
1017	// -- the entity has C language linkage
1018	// -- the entity is not odr-used or is defined in the same TU
1019	//
1020	// As an extension, accept this in cases where the type is externally
1021	// visible, since the function or variable actually can be defined in
1022	// another translation unit in that case.
1023	S.Diag(VD->getLocation(), isExternallyVisible(VD->getType()->getLinkage())
1024	? diag::ext_undefined_internal_type
1025	: diag::err_undefined_internal_type)
1026	<< isa<VarDecl>(VD) << VD;
1027	} else if (!VD->isExternallyVisible()) {
1028	// FIXME: We can promote this to an error. The function or variable can't
1029	// be defined anywhere else, so the program must necessarily violate the
1030	// one definition rule.
1031	bool IsImplicitBase = false;
1032	if (const auto *BaseD = dyn_cast<FunctionDecl>(Val: VD)) {
1033	auto *DVAttr = BaseD->getAttr<OMPDeclareVariantAttr>();
1034	if (DVAttr && !DVAttr->getTraitInfo().isExtensionActive(
1035	llvm::omp::TraitProperty::
1036	implementation_extension_disable_implicit_base)) {
1037	const auto *Func = cast<FunctionDecl>(
1038	cast<DeclRefExpr>(DVAttr->getVariantFuncRef())->getDecl());
1039	IsImplicitBase = BaseD->isImplicit() &&
1040	Func->getIdentifier()->isMangledOpenMPVariantName();
1041	}
1042	}
1043	if (!S.getLangOpts().OpenMP || !IsImplicitBase)
1044	S.Diag(VD->getLocation(), diag::warn_undefined_internal)
1045	<< isa<VarDecl>(VD) << VD;
1046	} else if (auto *FD = dyn_cast<FunctionDecl>(Val: VD)) {
1047	(void)FD;
1048	assert(FD->getMostRecentDecl()->isInlined() &&
1049	"used object requires definition but isn't inline or internal?");
1050	// FIXME: This is ill-formed; we should reject.
1051	S.Diag(VD->getLocation(), diag::warn_undefined_inline) << VD;
1052	} else {
1053	assert(cast<VarDecl>(VD)->getMostRecentDecl()->isInline() &&
1054	"used var requires definition but isn't inline or internal?");
1055	S.Diag(VD->getLocation(), diag::err_undefined_inline_var) << VD;
1056	}
1057	if (UseLoc.isValid())
1058	S.Diag(UseLoc, diag::note_used_here);
1059	}
1060	}
1061
1062	void Sema::LoadExternalWeakUndeclaredIdentifiers() {
1063	if (!ExternalSource)
1064	return;
1065
1066	SmallVector<std::pair<IdentifierInfo *, WeakInfo>, 4> WeakIDs;
1067	ExternalSource->ReadWeakUndeclaredIdentifiers(WI&: WeakIDs);
1068	for (auto &WeakID : WeakIDs)
1069	(void)WeakUndeclaredIdentifiers[WeakID.first].insert(X: WeakID.second);
1070	}
1071
1072
1073	typedef llvm::DenseMap<const CXXRecordDecl*, bool> RecordCompleteMap;
1074
1075	/// Returns true, if all methods and nested classes of the given
1076	/// CXXRecordDecl are defined in this translation unit.
1077	///
1078	/// Should only be called from ActOnEndOfTranslationUnit so that all
1079	/// definitions are actually read.
1080	static bool MethodsAndNestedClassesComplete(const CXXRecordDecl *RD,
1081	RecordCompleteMap &MNCComplete) {
1082	RecordCompleteMap::iterator Cache = MNCComplete.find(Val: RD);
1083	if (Cache != MNCComplete.end())
1084	return Cache->second;
1085	if (!RD->isCompleteDefinition())
1086	return false;
1087	bool Complete = true;
1088	for (DeclContext::decl_iterator I = RD->decls_begin(),
1089	E = RD->decls_end();
1090	I != E && Complete; ++I) {
1091	if (const CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Val: *I))
1092	Complete = M->isDefined() || M->isDefaulted() ||
1093	(M->isPureVirtual() && !isa<CXXDestructorDecl>(Val: M));
1094	else if (const FunctionTemplateDecl *F = dyn_cast<FunctionTemplateDecl>(Val: *I))
1095	// If the template function is marked as late template parsed at this
1096	// point, it has not been instantiated and therefore we have not
1097	// performed semantic analysis on it yet, so we cannot know if the type
1098	// can be considered complete.
1099	Complete = !F->getTemplatedDecl()->isLateTemplateParsed() &&
1100	F->getTemplatedDecl()->isDefined();
1101	else if (const CXXRecordDecl *R = dyn_cast<CXXRecordDecl>(Val: *I)) {
1102	if (R->isInjectedClassName())
1103	continue;
1104	if (R->hasDefinition())
1105	Complete = MethodsAndNestedClassesComplete(RD: R->getDefinition(),
1106	MNCComplete);
1107	else
1108	Complete = false;
1109	}
1110	}
1111	MNCComplete[RD] = Complete;
1112	return Complete;
1113	}
1114
1115	/// Returns true, if the given CXXRecordDecl is fully defined in this
1116	/// translation unit, i.e. all methods are defined or pure virtual and all
1117	/// friends, friend functions and nested classes are fully defined in this
1118	/// translation unit.
1119	///
1120	/// Should only be called from ActOnEndOfTranslationUnit so that all
1121	/// definitions are actually read.
1122	static bool IsRecordFullyDefined(const CXXRecordDecl *RD,
1123	RecordCompleteMap &RecordsComplete,
1124	RecordCompleteMap &MNCComplete) {
1125	RecordCompleteMap::iterator Cache = RecordsComplete.find(Val: RD);
1126	if (Cache != RecordsComplete.end())
1127	return Cache->second;
1128	bool Complete = MethodsAndNestedClassesComplete(RD, MNCComplete);
1129	for (CXXRecordDecl::friend_iterator I = RD->friend_begin(),
1130	E = RD->friend_end();
1131	I != E && Complete; ++I) {
1132	// Check if friend classes and methods are complete.
1133	if (TypeSourceInfo *TSI = (*I)->getFriendType()) {
1134	// Friend classes are available as the TypeSourceInfo of the FriendDecl.
1135	if (CXXRecordDecl *FriendD = TSI->getType()->getAsCXXRecordDecl())
1136	Complete = MethodsAndNestedClassesComplete(RD: FriendD, MNCComplete);
1137	else
1138	Complete = false;
1139	} else {
1140	// Friend functions are available through the NamedDecl of FriendDecl.
1141	if (const FunctionDecl *FD =
1142	dyn_cast<FunctionDecl>(Val: (*I)->getFriendDecl()))
1143	Complete = FD->isDefined();
1144	else
1145	// This is a template friend, give up.
1146	Complete = false;
1147	}
1148	}
1149	RecordsComplete[RD] = Complete;
1150	return Complete;
1151	}
1152
1153	void Sema::emitAndClearUnusedLocalTypedefWarnings() {
1154	if (ExternalSource)
1155	ExternalSource->ReadUnusedLocalTypedefNameCandidates(
1156	Decls&: UnusedLocalTypedefNameCandidates);
1157	for (const TypedefNameDecl *TD : UnusedLocalTypedefNameCandidates) {
1158	if (TD->isReferenced())
1159	continue;
1160	Diag(TD->getLocation(), diag::warn_unused_local_typedef)
1161	<< isa<TypeAliasDecl>(TD) << TD->getDeclName();
1162	}
1163	UnusedLocalTypedefNameCandidates.clear();
1164	}
1165
1166	void Sema::ActOnStartOfTranslationUnit() {
1167	if (getLangOpts().CPlusPlusModules &&
1168	getLangOpts().getCompilingModule() == LangOptions::CMK_HeaderUnit)
1169	HandleStartOfHeaderUnit();
1170	}
1171
1172	void Sema::ActOnEndOfTranslationUnitFragment(TUFragmentKind Kind) {
1173	if (Kind == TUFragmentKind::Global) {
1174	// Perform Pending Instantiations at the end of global module fragment so
1175	// that the module ownership of TU-level decls won't get messed.
1176	llvm::TimeTraceScope TimeScope("PerformPendingInstantiations");
1177	PerformPendingInstantiations();
1178	return;
1179	}
1180
1181	// Transfer late parsed template instantiations over to the pending template
1182	// instantiation list. During normal compilation, the late template parser
1183	// will be installed and instantiating these templates will succeed.
1184	//
1185	// If we are building a TU prefix for serialization, it is also safe to
1186	// transfer these over, even though they are not parsed. The end of the TU
1187	// should be outside of any eager template instantiation scope, so when this
1188	// AST is deserialized, these templates will not be parsed until the end of
1189	// the combined TU.
1190	PendingInstantiations.insert(position: PendingInstantiations.end(),
1191	first: LateParsedInstantiations.begin(),
1192	last: LateParsedInstantiations.end());
1193	LateParsedInstantiations.clear();
1194
1195	// If DefinedUsedVTables ends up marking any virtual member functions it
1196	// might lead to more pending template instantiations, which we then need
1197	// to instantiate.
1198	DefineUsedVTables();
1199
1200	// C++: Perform implicit template instantiations.
1201	//
1202	// FIXME: When we perform these implicit instantiations, we do not
1203	// carefully keep track of the point of instantiation (C++ [temp.point]).
1204	// This means that name lookup that occurs within the template
1205	// instantiation will always happen at the end of the translation unit,
1206	// so it will find some names that are not required to be found. This is
1207	// valid, but we could do better by diagnosing if an instantiation uses a
1208	// name that was not visible at its first point of instantiation.
1209	if (ExternalSource) {
1210	// Load pending instantiations from the external source.
1211	SmallVector<PendingImplicitInstantiation, 4> Pending;
1212	ExternalSource->ReadPendingInstantiations(Pending);
1213	for (auto PII : Pending)
1214	if (auto Func = dyn_cast<FunctionDecl>(Val: PII.first))
1215	Func->setInstantiationIsPending(true);
1216	PendingInstantiations.insert(position: PendingInstantiations.begin(),
1217	first: Pending.begin(), last: Pending.end());
1218	}
1219
1220	{
1221	llvm::TimeTraceScope TimeScope("PerformPendingInstantiations");
1222	PerformPendingInstantiations();
1223	}
1224
1225	emitDeferredDiags();
1226
1227	assert(LateParsedInstantiations.empty() &&
1228	"end of TU template instantiation should not create more "
1229	"late-parsed templates");
1230
1231	// Report diagnostics for uncorrected delayed typos. Ideally all of them
1232	// should have been corrected by that time, but it is very hard to cover all
1233	// cases in practice.
1234	for (const auto &Typo : DelayedTypos) {
1235	// We pass an empty TypoCorrection to indicate no correction was performed.
1236	Typo.second.DiagHandler(TypoCorrection());
1237	}
1238	DelayedTypos.clear();
1239	}
1240
1241	void Sema::ActOnEndOfTranslationUnit() {
1242	assert(DelayedDiagnostics.getCurrentPool() == nullptr
1243	&& "reached end of translation unit with a pool attached?");
1244
1245	// If code completion is enabled, don't perform any end-of-translation-unit
1246	// work.
1247	if (PP.isCodeCompletionEnabled())
1248	return;
1249
1250	// Complete translation units and modules define vtables and perform implicit
1251	// instantiations. PCH files do not.
1252	if (TUKind != TU_Prefix) {
1253	ObjC().DiagnoseUseOfUnimplementedSelectors();
1254
1255	ActOnEndOfTranslationUnitFragment(
1256	Kind: !ModuleScopes.empty() && ModuleScopes.back().Module->Kind ==
1257	Module::PrivateModuleFragment
1258	? TUFragmentKind::Private
1259	: TUFragmentKind::Normal);
1260
1261	if (LateTemplateParserCleanup)
1262	LateTemplateParserCleanup(OpaqueParser);
1263
1264	CheckDelayedMemberExceptionSpecs();
1265	} else {
1266	// If we are building a TU prefix for serialization, it is safe to transfer
1267	// these over, even though they are not parsed. The end of the TU should be
1268	// outside of any eager template instantiation scope, so when this AST is
1269	// deserialized, these templates will not be parsed until the end of the
1270	// combined TU.
1271	PendingInstantiations.insert(position: PendingInstantiations.end(),
1272	first: LateParsedInstantiations.begin(),
1273	last: LateParsedInstantiations.end());
1274	LateParsedInstantiations.clear();
1275
1276	if (LangOpts.PCHInstantiateTemplates) {
1277	llvm::TimeTraceScope TimeScope("PerformPendingInstantiations");
1278	PerformPendingInstantiations();
1279	}
1280	}
1281
1282	DiagnoseUnterminatedPragmaAlignPack();
1283	DiagnoseUnterminatedPragmaAttribute();
1284	OpenMP().DiagnoseUnterminatedOpenMPDeclareTarget();
1285	DiagnosePrecisionLossInComplexDivision();
1286
1287	// All delayed member exception specs should be checked or we end up accepting
1288	// incompatible declarations.
1289	assert(DelayedOverridingExceptionSpecChecks.empty());
1290	assert(DelayedEquivalentExceptionSpecChecks.empty());
1291
1292	// All dllexport classes should have been processed already.
1293	assert(DelayedDllExportClasses.empty());
1294	assert(DelayedDllExportMemberFunctions.empty());
1295
1296	// Remove file scoped decls that turned out to be used.
1297	UnusedFileScopedDecls.erase(
1298	From: std::remove_if(first: UnusedFileScopedDecls.begin(source: nullptr, LocalOnly: true),
1299	last: UnusedFileScopedDecls.end(),
1300	pred: [this](const DeclaratorDecl *DD) {
1301	return ShouldRemoveFromUnused(SemaRef: this, D: DD);
1302	}),
1303	To: UnusedFileScopedDecls.end());
1304
1305	if (TUKind == TU_Prefix) {
1306	// Translation unit prefixes don't need any of the checking below.
1307	if (!PP.isIncrementalProcessingEnabled())
1308	TUScope = nullptr;
1309	return;
1310	}
1311
1312	// Check for #pragma weak identifiers that were never declared
1313	LoadExternalWeakUndeclaredIdentifiers();
1314	for (const auto &WeakIDs : WeakUndeclaredIdentifiers) {
1315	if (WeakIDs.second.empty())
1316	continue;
1317
1318	Decl *PrevDecl = LookupSingleName(S: TUScope, Name: WeakIDs.first, Loc: SourceLocation(),
1319	NameKind: LookupOrdinaryName);
1320	if (PrevDecl != nullptr &&
1321	!(isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl)))
1322	for (const auto &WI : WeakIDs.second)
1323	Diag(WI.getLocation(), diag::warn_attribute_wrong_decl_type)
1324	<< "'weak'" << /*isRegularKeyword=*/0 << ExpectedVariableOrFunction;
1325	else
1326	for (const auto &WI : WeakIDs.second)
1327	Diag(WI.getLocation(), diag::warn_weak_identifier_undeclared)
1328	<< WeakIDs.first;
1329	}
1330
1331	if (LangOpts.CPlusPlus11 &&
1332	!Diags.isIgnored(diag::warn_delegating_ctor_cycle, SourceLocation()))
1333	CheckDelegatingCtorCycles();
1334
1335	if (!Diags.hasErrorOccurred()) {
1336	if (ExternalSource)
1337	ExternalSource->ReadUndefinedButUsed(Undefined&: UndefinedButUsed);
1338	checkUndefinedButUsed(S&: *this);
1339	}
1340
1341	// A global-module-fragment is only permitted within a module unit.
1342	if (!ModuleScopes.empty() && ModuleScopes.back().Module->Kind ==
1343	Module::ExplicitGlobalModuleFragment) {
1344	Diag(ModuleScopes.back().BeginLoc,
1345	diag::err_module_declaration_missing_after_global_module_introducer);
1346	} else if (getLangOpts().getCompilingModule() ==
1347	LangOptions::CMK_ModuleInterface &&
1348	// We can't use ModuleScopes here since ModuleScopes is always
1349	// empty if we're compiling the BMI.
1350	!getASTContext().getCurrentNamedModule()) {
1351	// If we are building a module interface unit, we should have seen the
1352	// module declaration.
1353	//
1354	// FIXME: Make a better guess as to where to put the module declaration.
1355	Diag(getSourceManager().getLocForStartOfFile(
1356	getSourceManager().getMainFileID()),
1357	diag::err_module_declaration_missing);
1358	}
1359
1360	// Now we can decide whether the modules we're building need an initializer.
1361	if (Module *CurrentModule = getCurrentModule();
1362	CurrentModule && CurrentModule->isInterfaceOrPartition()) {
1363	auto DoesModNeedInit = [this](Module *M) {
1364	if (!getASTContext().getModuleInitializers(M).empty())
1365	return true;
1366	for (auto [Exported, _] : M->Exports)
1367	if (Exported->isNamedModuleInterfaceHasInit())
1368	return true;
1369	for (Module *I : M->Imports)
1370	if (I->isNamedModuleInterfaceHasInit())
1371	return true;
1372
1373	return false;
1374	};
1375
1376	CurrentModule->NamedModuleHasInit =
1377	DoesModNeedInit(CurrentModule) ||
1378	llvm::any_of(Range: CurrentModule->submodules(), P: DoesModNeedInit);
1379	}
1380
1381	if (TUKind == TU_ClangModule) {
1382	// If we are building a module, resolve all of the exported declarations
1383	// now.
1384	if (Module *CurrentModule = PP.getCurrentModule()) {
1385	ModuleMap &ModMap = PP.getHeaderSearchInfo().getModuleMap();
1386
1387	SmallVector<Module *, 2> Stack;
1388	Stack.push_back(Elt: CurrentModule);
1389	while (!Stack.empty()) {
1390	Module *Mod = Stack.pop_back_val();
1391
1392	// Resolve the exported declarations and conflicts.
1393	// FIXME: Actually complain, once we figure out how to teach the
1394	// diagnostic client to deal with complaints in the module map at this
1395	// point.
1396	ModMap.resolveExports(Mod, /*Complain=*/false);
1397	ModMap.resolveUses(Mod, /*Complain=*/false);
1398	ModMap.resolveConflicts(Mod, /*Complain=*/false);
1399
1400	// Queue the submodules, so their exports will also be resolved.
1401	auto SubmodulesRange = Mod->submodules();
1402	Stack.append(in_start: SubmodulesRange.begin(), in_end: SubmodulesRange.end());
1403	}
1404	}
1405
1406	// Warnings emitted in ActOnEndOfTranslationUnit() should be emitted for
1407	// modules when they are built, not every time they are used.
1408	emitAndClearUnusedLocalTypedefWarnings();
1409	}
1410
1411	// C++ standard modules. Diagnose cases where a function is declared inline
1412	// in the module purview but has no definition before the end of the TU or
1413	// the start of a Private Module Fragment (if one is present).
1414	if (!PendingInlineFuncDecls.empty()) {
1415	for (auto *D : PendingInlineFuncDecls) {
1416	if (auto *FD = dyn_cast<FunctionDecl>(Val: D)) {
1417	bool DefInPMF = false;
1418	if (auto *FDD = FD->getDefinition()) {
1419	DefInPMF = FDD->getOwningModule()->isPrivateModule();
1420	if (!DefInPMF)
1421	continue;
1422	}
1423	Diag(FD->getLocation(), diag::err_export_inline_not_defined)
1424	<< DefInPMF;
1425	// If we have a PMF it should be at the end of the ModuleScopes.
1426	if (DefInPMF &&
1427	ModuleScopes.back().Module->Kind == Module::PrivateModuleFragment) {
1428	Diag(ModuleScopes.back().BeginLoc,
1429	diag::note_private_module_fragment);
1430	}
1431	}
1432	}
1433	PendingInlineFuncDecls.clear();
1434	}
1435
1436	// C99 6.9.2p2:
1437	// A declaration of an identifier for an object that has file
1438	// scope without an initializer, and without a storage-class
1439	// specifier or with the storage-class specifier static,
1440	// constitutes a tentative definition. If a translation unit
1441	// contains one or more tentative definitions for an identifier,
1442	// and the translation unit contains no external definition for
1443	// that identifier, then the behavior is exactly as if the
1444	// translation unit contains a file scope declaration of that
1445	// identifier, with the composite type as of the end of the
1446	// translation unit, with an initializer equal to 0.
1447	llvm::SmallSet<VarDecl *, 32> Seen;
1448	for (TentativeDefinitionsType::iterator
1449	T = TentativeDefinitions.begin(source: ExternalSource.get()),
1450	TEnd = TentativeDefinitions.end();
1451	T != TEnd; ++T) {
1452	VarDecl *VD = (*T)->getActingDefinition();
1453
1454	// If the tentative definition was completed, getActingDefinition() returns
1455	// null. If we've already seen this variable before, insert()'s second
1456	// return value is false.
1457	if (!VD || VD->isInvalidDecl() || !Seen.insert(Ptr: VD).second)
1458	continue;
1459
1460	if (const IncompleteArrayType *ArrayT
1461	= Context.getAsIncompleteArrayType(T: VD->getType())) {
1462	// Set the length of the array to 1 (C99 6.9.2p5).
1463	Diag(VD->getLocation(), diag::warn_tentative_incomplete_array);
1464	llvm::APInt One(Context.getTypeSize(T: Context.getSizeType()), true);
1465	QualType T = Context.getConstantArrayType(
1466	EltTy: ArrayT->getElementType(), ArySize: One, SizeExpr: nullptr, ASM: ArraySizeModifier::Normal, IndexTypeQuals: 0);
1467	VD->setType(T);
1468	} else if (RequireCompleteType(VD->getLocation(), VD->getType(),
1469	diag::err_tentative_def_incomplete_type))
1470	VD->setInvalidDecl();
1471
1472	// No initialization is performed for a tentative definition.
1473	CheckCompleteVariableDeclaration(VD);
1474
1475	// In C, if the definition is const-qualified and has no initializer, it
1476	// is left uninitialized unless it has static or thread storage duration.
1477	QualType Type = VD->getType();
1478	if (!VD->isInvalidDecl() && !getLangOpts().CPlusPlus &&
1479	Type.isConstQualified() && !VD->getAnyInitializer()) {
1480	unsigned DiagID = diag::warn_default_init_const_unsafe;
1481	if (VD->getStorageDuration() == SD_Static ||
1482	VD->getStorageDuration() == SD_Thread)
1483	DiagID = diag::warn_default_init_const;
1484
1485	bool EmitCppCompat = !Diags.isIgnored(
1486	diag::warn_cxx_compat_hack_fake_diagnostic_do_not_emit,
1487	VD->getLocation());
1488
1489	Diag(VD->getLocation(), DiagID) << Type << EmitCppCompat;
1490	}
1491
1492	// Notify the consumer that we've completed a tentative definition.
1493	if (!VD->isInvalidDecl())
1494	Consumer.CompleteTentativeDefinition(D: VD);
1495	}
1496
1497	for (auto *D : ExternalDeclarations) {
1498	if (!D || D->isInvalidDecl() || D->getPreviousDecl() || !D->isUsed())
1499	continue;
1500
1501	Consumer.CompleteExternalDeclaration(D);
1502	}
1503
1504	if (LangOpts.HLSL)
1505	HLSL().ActOnEndOfTranslationUnit(TU: getASTContext().getTranslationUnitDecl());
1506
1507	// If there were errors, disable 'unused' warnings since they will mostly be
1508	// noise. Don't warn for a use from a module: either we should warn on all
1509	// file-scope declarations in modules or not at all, but whether the
1510	// declaration is used is immaterial.
1511	if (!Diags.hasErrorOccurred() && TUKind != TU_ClangModule) {
1512	// Output warning for unused file scoped decls.
1513	for (UnusedFileScopedDeclsType::iterator
1514	I = UnusedFileScopedDecls.begin(source: ExternalSource.get()),
1515	E = UnusedFileScopedDecls.end();
1516	I != E; ++I) {
1517	if (ShouldRemoveFromUnused(SemaRef: this, D: *I))
1518	continue;
1519
1520	if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: *I)) {
1521	const FunctionDecl *DiagD;
1522	if (!FD->hasBody(Definition&: DiagD))
1523	DiagD = FD;
1524	if (DiagD->isDeleted())
1525	continue; // Deleted functions are supposed to be unused.
1526	SourceRange DiagRange = DiagD->getLocation();
1527	if (const ASTTemplateArgumentListInfo *ASTTAL =
1528	DiagD->getTemplateSpecializationArgsAsWritten())
1529	DiagRange.setEnd(ASTTAL->RAngleLoc);
1530	if (DiagD->isReferenced()) {
1531	if (isa<CXXMethodDecl>(Val: DiagD))
1532	Diag(DiagD->getLocation(), diag::warn_unneeded_member_function)
1533	<< DiagD << DiagRange;
1534	else {
1535	if (FD->getStorageClass() == SC_Static &&
1536	!FD->isInlineSpecified() &&
1537	!SourceMgr.isInMainFile(
1538	SourceMgr.getExpansionLoc(FD->getLocation())))
1539	Diag(DiagD->getLocation(),
1540	diag::warn_unneeded_static_internal_decl)
1541	<< DiagD << DiagRange;
1542	else
1543	Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
1544	<< /*function=*/0 << DiagD << DiagRange;
1545	}
1546	} else if (!FD->isTargetMultiVersion() ||
1547	FD->isTargetMultiVersionDefault()) {
1548	if (FD->getDescribedFunctionTemplate())
1549	Diag(DiagD->getLocation(), diag::warn_unused_template)
1550	<< /*function=*/0 << DiagD << DiagRange;
1551	else
1552	Diag(DiagD->getLocation(), isa<CXXMethodDecl>(DiagD)
1553	? diag::warn_unused_member_function
1554	: diag::warn_unused_function)
1555	<< DiagD << DiagRange;
1556	}
1557	} else {
1558	const VarDecl *DiagD = cast<VarDecl>(Val: *I)->getDefinition();
1559	if (!DiagD)
1560	DiagD = cast<VarDecl>(Val: *I);
1561	SourceRange DiagRange = DiagD->getLocation();
1562	if (const auto *VTSD = dyn_cast<VarTemplateSpecializationDecl>(Val: DiagD)) {
1563	if (const ASTTemplateArgumentListInfo *ASTTAL =
1564	VTSD->getTemplateArgsAsWritten())
1565	DiagRange.setEnd(ASTTAL->RAngleLoc);
1566	}
1567	if (DiagD->isReferenced()) {
1568	Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
1569	<< /*variable=*/1 << DiagD << DiagRange;
1570	} else if (DiagD->getDescribedVarTemplate()) {
1571	Diag(DiagD->getLocation(), diag::warn_unused_template)
1572	<< /*variable=*/1 << DiagD << DiagRange;
1573	} else if (DiagD->getType().isConstQualified()) {
1574	const SourceManager &SM = SourceMgr;
1575	if (SM.getMainFileID() != SM.getFileID(DiagD->getLocation()) ||
1576	!PP.getLangOpts().IsHeaderFile)
1577	Diag(DiagD->getLocation(), diag::warn_unused_const_variable)
1578	<< DiagD << DiagRange;
1579	} else {
1580	Diag(DiagD->getLocation(), diag::warn_unused_variable)
1581	<< DiagD << DiagRange;
1582	}
1583	}
1584	}
1585
1586	emitAndClearUnusedLocalTypedefWarnings();
1587	}
1588
1589	if (!Diags.isIgnored(diag::warn_unused_private_field, SourceLocation())) {
1590	// FIXME: Load additional unused private field candidates from the external
1591	// source.
1592	RecordCompleteMap RecordsComplete;
1593	RecordCompleteMap MNCComplete;
1594	for (const NamedDecl *D : UnusedPrivateFields) {
1595	const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
1596	if (RD && !RD->isUnion() &&
1597	IsRecordFullyDefined(RD, RecordsComplete, MNCComplete)) {
1598	Diag(D->getLocation(), diag::warn_unused_private_field)
1599	<< D->getDeclName();
1600	}
1601	}
1602	}
1603
1604	if (!Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation())) {
1605	if (ExternalSource)
1606	ExternalSource->ReadMismatchingDeleteExpressions(DeleteExprs);
1607	for (const auto &DeletedFieldInfo : DeleteExprs) {
1608	for (const auto &DeleteExprLoc : DeletedFieldInfo.second) {
1609	AnalyzeDeleteExprMismatch(Field: DeletedFieldInfo.first, DeleteLoc: DeleteExprLoc.first,
1610	DeleteWasArrayForm: DeleteExprLoc.second);
1611	}
1612	}
1613	}
1614
1615	AnalysisWarnings.IssueWarnings(D: Context.getTranslationUnitDecl());
1616
1617	if (Context.hasAnyFunctionEffects())
1618	performFunctionEffectAnalysis(TU: Context.getTranslationUnitDecl());
1619
1620	// Check we've noticed that we're no longer parsing the initializer for every
1621	// variable. If we miss cases, then at best we have a performance issue and
1622	// at worst a rejects-valid bug.
1623	assert(ParsingInitForAutoVars.empty() &&
1624	"Didn't unmark var as having its initializer parsed");
1625
1626	if (!PP.isIncrementalProcessingEnabled())
1627	TUScope = nullptr;
1628	}
1629
1630
1631	//===----------------------------------------------------------------------===//
1632	// Helper functions.
1633	//===----------------------------------------------------------------------===//
1634
1635	DeclContext *Sema::getFunctionLevelDeclContext(bool AllowLambda) const {
1636	DeclContext *DC = CurContext;
1637
1638	while (true) {
1639	if (isa<BlockDecl>(Val: DC) || isa<EnumDecl>(Val: DC) || isa<CapturedDecl>(Val: DC) ||
1640	isa<RequiresExprBodyDecl>(Val: DC)) {
1641	DC = DC->getParent();
1642	} else if (!AllowLambda && isa<CXXMethodDecl>(Val: DC) &&
1643	cast<CXXMethodDecl>(Val: DC)->getOverloadedOperator() == OO_Call &&
1644	cast<CXXRecordDecl>(Val: DC->getParent())->isLambda()) {
1645	DC = DC->getParent()->getParent();
1646	} else break;
1647	}
1648
1649	return DC;
1650	}
1651
1652	/// getCurFunctionDecl - If inside of a function body, this returns a pointer
1653	/// to the function decl for the function being parsed. If we're currently
1654	/// in a 'block', this returns the containing context.
1655	FunctionDecl *Sema::getCurFunctionDecl(bool AllowLambda) const {
1656	DeclContext *DC = getFunctionLevelDeclContext(AllowLambda);
1657	return dyn_cast<FunctionDecl>(Val: DC);
1658	}
1659
1660	ObjCMethodDecl *Sema::getCurMethodDecl() {
1661	DeclContext *DC = getFunctionLevelDeclContext();
1662	while (isa<RecordDecl>(Val: DC))
1663	DC = DC->getParent();
1664	return dyn_cast<ObjCMethodDecl>(Val: DC);
1665	}
1666
1667	NamedDecl *Sema::getCurFunctionOrMethodDecl() const {
1668	DeclContext *DC = getFunctionLevelDeclContext();
1669	if (isa<ObjCMethodDecl>(Val: DC) || isa<FunctionDecl>(Val: DC))
1670	return cast<NamedDecl>(Val: DC);
1671	return nullptr;
1672	}
1673
1674	LangAS Sema::getDefaultCXXMethodAddrSpace() const {
1675	if (getLangOpts().OpenCL)
1676	return getASTContext().getDefaultOpenCLPointeeAddrSpace();
1677	return LangAS::Default;
1678	}
1679
1680	void Sema::EmitDiagnostic(unsigned DiagID, const DiagnosticBuilder &DB) {
1681	// FIXME: It doesn't make sense to me that DiagID is an incoming argument here
1682	// and yet we also use the current diag ID on the DiagnosticsEngine. This has
1683	// been made more painfully obvious by the refactor that introduced this
1684	// function, but it is possible that the incoming argument can be
1685	// eliminated. If it truly cannot be (for example, there is some reentrancy
1686	// issue I am not seeing yet), then there should at least be a clarifying
1687	// comment somewhere.
1688	Diagnostic DiagInfo(&Diags, DB);
1689	if (std::optional<TemplateDeductionInfo *> Info = isSFINAEContext()) {
1690	switch (DiagnosticIDs::getDiagnosticSFINAEResponse(DiagID: DiagInfo.getID())) {
1691	case DiagnosticIDs::SFINAE_Report:
1692	// We'll report the diagnostic below.
1693	break;
1694
1695	case DiagnosticIDs::SFINAE_SubstitutionFailure:
1696	// Count this failure so that we know that template argument deduction
1697	// has failed.
1698	++NumSFINAEErrors;
1699
1700	// Make a copy of this suppressed diagnostic and store it with the
1701	// template-deduction information.
1702	if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
1703	(*Info)->addSFINAEDiagnostic(Loc: DiagInfo.getLocation(),
1704	PD: PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
1705	}
1706
1707	Diags.setLastDiagnosticIgnored(true);
1708	return;
1709
1710	case DiagnosticIDs::SFINAE_AccessControl: {
1711	// Per C++ Core Issue 1170, access control is part of SFINAE.
1712	// Additionally, the AccessCheckingSFINAE flag can be used to temporarily
1713	// make access control a part of SFINAE for the purposes of checking
1714	// type traits.
1715	if (!AccessCheckingSFINAE && !getLangOpts().CPlusPlus11)
1716	break;
1717
1718	SourceLocation Loc = DiagInfo.getLocation();
1719
1720	// Suppress this diagnostic.
1721	++NumSFINAEErrors;
1722
1723	// Make a copy of this suppressed diagnostic and store it with the
1724	// template-deduction information.
1725	if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
1726	(*Info)->addSFINAEDiagnostic(Loc: DiagInfo.getLocation(),
1727	PD: PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
1728	}
1729
1730	Diags.setLastDiagnosticIgnored(true);
1731
1732	// Now produce a C++98 compatibility warning.
1733	Diag(Loc, diag::warn_cxx98_compat_sfinae_access_control);
1734
1735	// The last diagnostic which Sema produced was ignored. Suppress any
1736	// notes attached to it.
1737	Diags.setLastDiagnosticIgnored(true);
1738	return;
1739	}
1740
1741	case DiagnosticIDs::SFINAE_Suppress:
1742	if (DiagnosticsEngine::Level Level = getDiagnostics().getDiagnosticLevel(
1743	DiagID: DiagInfo.getID(), Loc: DiagInfo.getLocation());
1744	Level == DiagnosticsEngine::Ignored)
1745	return;
1746	// Make a copy of this suppressed diagnostic and store it with the
1747	// template-deduction information;
1748	if (*Info) {
1749	(*Info)->addSuppressedDiagnostic(
1750	Loc: DiagInfo.getLocation(),
1751	PD: PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
1752	if (!Diags.getDiagnosticIDs()->isNote(DiagID))
1753	PrintContextStack(DiagFunc: [Info](SourceLocation Loc, PartialDiagnostic PD) {
1754	(*Info)->addSuppressedDiagnostic(Loc, PD: std::move(PD));
1755	});
1756	}
1757
1758	// Suppress this diagnostic.
1759	Diags.setLastDiagnosticIgnored(true);
1760	return;
1761	}
1762	}
1763
1764	// Copy the diagnostic printing policy over the ASTContext printing policy.
1765	// TODO: Stop doing that. See: https://reviews.llvm.org/D45093#1090292
1766	Context.setPrintingPolicy(getPrintingPolicy());
1767
1768	// Emit the diagnostic.
1769	if (!Diags.EmitDiagnostic(DB))
1770	return;
1771
1772	// If this is not a note, and we're in a template instantiation
1773	// that is different from the last template instantiation where
1774	// we emitted an error, print a template instantiation
1775	// backtrace.
1776	if (!Diags.getDiagnosticIDs()->isNote(DiagID))
1777	PrintContextStack();
1778	}
1779
1780	bool Sema::hasUncompilableErrorOccurred() const {
1781	if (getDiagnostics().hasUncompilableErrorOccurred())
1782	return true;
1783	auto *FD = dyn_cast<FunctionDecl>(Val: CurContext);
1784	if (!FD)
1785	return false;
1786	auto Loc = DeviceDeferredDiags.find(Val: FD);
1787	if (Loc == DeviceDeferredDiags.end())
1788	return false;
1789	for (auto PDAt : Loc->second) {
1790	if (Diags.getDiagnosticIDs()->isDefaultMappingAsError(
1791	DiagID: PDAt.second.getDiagID()))
1792	return true;
1793	}
1794	return false;
1795	}
1796
1797	// Print notes showing how we can reach FD starting from an a priori
1798	// known-callable function.
1799	static void emitCallStackNotes(Sema &S, const FunctionDecl *FD) {
1800	auto FnIt = S.CUDA().DeviceKnownEmittedFns.find(Val: FD);
1801	while (FnIt != S.CUDA().DeviceKnownEmittedFns.end()) {
1802	// Respect error limit.
1803	if (S.Diags.hasFatalErrorOccurred())
1804	return;
1805	DiagnosticBuilder Builder(
1806	S.Diags.Report(FnIt->second.Loc, diag::note_called_by));
1807	Builder << FnIt->second.FD;
1808	FnIt = S.CUDA().DeviceKnownEmittedFns.find(Val: FnIt->second.FD);
1809	}
1810	}
1811
1812	namespace {
1813
1814	/// Helper class that emits deferred diagnostic messages if an entity directly
1815	/// or indirectly using the function that causes the deferred diagnostic
1816	/// messages is known to be emitted.
1817	///
1818	/// During parsing of AST, certain diagnostic messages are recorded as deferred
1819	/// diagnostics since it is unknown whether the functions containing such
1820	/// diagnostics will be emitted. A list of potentially emitted functions and
1821	/// variables that may potentially trigger emission of functions are also
1822	/// recorded. DeferredDiagnosticsEmitter recursively visits used functions
1823	/// by each function to emit deferred diagnostics.
1824	///
1825	/// During the visit, certain OpenMP directives or initializer of variables
1826	/// with certain OpenMP attributes will cause subsequent visiting of any
1827	/// functions enter a state which is called OpenMP device context in this
1828	/// implementation. The state is exited when the directive or initializer is
1829	/// exited. This state can change the emission states of subsequent uses
1830	/// of functions.
1831	///
1832	/// Conceptually the functions or variables to be visited form a use graph
1833	/// where the parent node uses the child node. At any point of the visit,
1834	/// the tree nodes traversed from the tree root to the current node form a use
1835	/// stack. The emission state of the current node depends on two factors:
1836	/// 1. the emission state of the root node
1837	/// 2. whether the current node is in OpenMP device context
1838	/// If the function is decided to be emitted, its contained deferred diagnostics
1839	/// are emitted, together with the information about the use stack.
1840	///
1841	class DeferredDiagnosticsEmitter
1842	: public UsedDeclVisitor<DeferredDiagnosticsEmitter> {
1843	public:
1844	typedef UsedDeclVisitor<DeferredDiagnosticsEmitter> Inherited;
1845
1846	// Whether the function is already in the current use-path.
1847	llvm::SmallPtrSet<CanonicalDeclPtr<Decl>, 4> InUsePath;
1848
1849	// The current use-path.
1850	llvm::SmallVector<CanonicalDeclPtr<FunctionDecl>, 4> UsePath;
1851
1852	// Whether the visiting of the function has been done. Done[0] is for the
1853	// case not in OpenMP device context. Done[1] is for the case in OpenMP
1854	// device context. We need two sets because diagnostics emission may be
1855	// different depending on whether it is in OpenMP device context.
1856	llvm::SmallPtrSet<CanonicalDeclPtr<Decl>, 4> DoneMap[2];
1857
1858	// Emission state of the root node of the current use graph.
1859	bool ShouldEmitRootNode;
1860
1861	// Current OpenMP device context level. It is initialized to 0 and each
1862	// entering of device context increases it by 1 and each exit decreases
1863	// it by 1. Non-zero value indicates it is currently in device context.
1864	unsigned InOMPDeviceContext;
1865
1866	DeferredDiagnosticsEmitter(Sema &S)
1867	: Inherited(S), ShouldEmitRootNode(false), InOMPDeviceContext(0) {}
1868
1869	bool shouldVisitDiscardedStmt() const { return false; }
1870
1871	void VisitOMPTargetDirective(OMPTargetDirective *Node) {
1872	++InOMPDeviceContext;
1873	Inherited::VisitOMPTargetDirective(Node);
1874	--InOMPDeviceContext;
1875	}
1876
1877	void visitUsedDecl(SourceLocation Loc, Decl *D) {
1878	if (isa<VarDecl>(Val: D))
1879	return;
1880	if (auto *FD = dyn_cast<FunctionDecl>(Val: D))
1881	checkFunc(Loc, FD);
1882	else
1883	Inherited::visitUsedDecl(Loc, D);
1884	}
1885
1886	// Visitor member and parent dtors called by this dtor.
1887	void VisitCalledDestructors(CXXDestructorDecl *DD) {
1888	const CXXRecordDecl *RD = DD->getParent();
1889
1890	// Visit the dtors of all members
1891	for (const FieldDecl *FD : RD->fields()) {
1892	QualType FT = FD->getType();
1893	if (const auto *RT = FT->getAs<RecordType>())
1894	if (const auto *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1895	if (ClassDecl->hasDefinition())
1896	if (CXXDestructorDecl *MemberDtor = ClassDecl->getDestructor())
1897	asImpl().visitUsedDecl(MemberDtor->getLocation(), MemberDtor);
1898	}
1899
1900	// Also visit base class dtors
1901	for (const auto &Base : RD->bases()) {
1902	QualType BaseType = Base.getType();
1903	if (const auto *RT = BaseType->getAs<RecordType>())
1904	if (const auto *BaseDecl = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1905	if (BaseDecl->hasDefinition())
1906	if (CXXDestructorDecl *BaseDtor = BaseDecl->getDestructor())
1907	asImpl().visitUsedDecl(BaseDtor->getLocation(), BaseDtor);
1908	}
1909	}
1910
1911	void VisitDeclStmt(DeclStmt *DS) {
1912	// Visit dtors called by variables that need destruction
1913	for (auto *D : DS->decls())
1914	if (auto *VD = dyn_cast<VarDecl>(Val: D))
1915	if (VD->isThisDeclarationADefinition() &&
1916	VD->needsDestruction(Ctx: S.Context)) {
1917	QualType VT = VD->getType();
1918	if (const auto *RT = VT->getAs<RecordType>())
1919	if (const auto *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1920	if (ClassDecl->hasDefinition())
1921	if (CXXDestructorDecl *Dtor = ClassDecl->getDestructor())
1922	asImpl().visitUsedDecl(Loc: Dtor->getLocation(), D: Dtor);
1923	}
1924
1925	Inherited::VisitDeclStmt(DS);
1926	}
1927	void checkVar(VarDecl *VD) {
1928	assert(VD->isFileVarDecl() &&
1929	"Should only check file-scope variables");
1930	if (auto *Init = VD->getInit()) {
1931	auto DevTy = OMPDeclareTargetDeclAttr::getDeviceType(VD);
1932	bool IsDev = DevTy && (*DevTy == OMPDeclareTargetDeclAttr::DT_NoHost ||
1933	*DevTy == OMPDeclareTargetDeclAttr::DT_Any);
1934	if (IsDev)
1935	++InOMPDeviceContext;
1936	this->Visit(Init);
1937	if (IsDev)
1938	--InOMPDeviceContext;
1939	}
1940	}
1941
1942	void checkFunc(SourceLocation Loc, FunctionDecl *FD) {
1943	auto &Done = DoneMap[InOMPDeviceContext > 0 ? 1 : 0];
1944	FunctionDecl *Caller = UsePath.empty() ? nullptr : UsePath.back();
1945	if ((!ShouldEmitRootNode && !S.getLangOpts().OpenMP && !Caller) ||
1946	S.shouldIgnoreInHostDeviceCheck(Callee: FD) || InUsePath.count(FD))
1947	return;
1948	// Finalize analysis of OpenMP-specific constructs.
1949	if (Caller && S.LangOpts.OpenMP && UsePath.size() == 1 &&
1950	(ShouldEmitRootNode || InOMPDeviceContext))
1951	S.OpenMP().finalizeOpenMPDelayedAnalysis(Caller, Callee: FD, Loc);
1952	if (Caller)
1953	S.CUDA().DeviceKnownEmittedFns[FD] = {.FD: Caller, .Loc: Loc};
1954	// Always emit deferred diagnostics for the direct users. This does not
1955	// lead to explosion of diagnostics since each user is visited at most
1956	// twice.
1957	if (ShouldEmitRootNode || InOMPDeviceContext)
1958	emitDeferredDiags(FD, ShowCallStack: Caller);
1959	// Do not revisit a function if the function body has been completely
1960	// visited before.
1961	if (!Done.insert(FD).second)
1962	return;
1963	InUsePath.insert(FD);
1964	UsePath.push_back(Elt: FD);
1965	if (auto *S = FD->getBody()) {
1966	this->Visit(S);
1967	}
1968	if (CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(Val: FD))
1969	asImpl().VisitCalledDestructors(DD: Dtor);
1970	UsePath.pop_back();
1971	InUsePath.erase(FD);
1972	}
1973
1974	void checkRecordedDecl(Decl *D) {
1975	if (auto *FD = dyn_cast<FunctionDecl>(Val: D)) {
1976	ShouldEmitRootNode = S.getEmissionStatus(Decl: FD, /*Final=*/true) ==
1977	Sema::FunctionEmissionStatus::Emitted;
1978	checkFunc(Loc: SourceLocation(), FD);
1979	} else
1980	checkVar(VD: cast<VarDecl>(Val: D));
1981	}
1982
1983	// Emit any deferred diagnostics for FD
1984	void emitDeferredDiags(FunctionDecl *FD, bool ShowCallStack) {
1985	auto It = S.DeviceDeferredDiags.find(Val: FD);
1986	if (It == S.DeviceDeferredDiags.end())
1987	return;
1988	bool HasWarningOrError = false;
1989	bool FirstDiag = true;
1990	for (PartialDiagnosticAt &PDAt : It->second) {
1991	// Respect error limit.
1992	if (S.Diags.hasFatalErrorOccurred())
1993	return;
1994	const SourceLocation &Loc = PDAt.first;
1995	const PartialDiagnostic &PD = PDAt.second;
1996	HasWarningOrError |=
1997	S.getDiagnostics().getDiagnosticLevel(DiagID: PD.getDiagID(), Loc) >=
1998	DiagnosticsEngine::Warning;
1999	{
2000	DiagnosticBuilder Builder(S.Diags.Report(Loc, DiagID: PD.getDiagID()));
2001	PD.Emit(DB: Builder);
2002	}
2003	// Emit the note on the first diagnostic in case too many diagnostics
2004	// cause the note not emitted.
2005	if (FirstDiag && HasWarningOrError && ShowCallStack) {
2006	emitCallStackNotes(S, FD);
2007	FirstDiag = false;
2008	}
2009	}
2010	}
2011	};
2012	} // namespace
2013
2014	void Sema::emitDeferredDiags() {
2015	if (ExternalSource)
2016	ExternalSource->ReadDeclsToCheckForDeferredDiags(
2017	Decls&: DeclsToCheckForDeferredDiags);
2018
2019	if ((DeviceDeferredDiags.empty() && !LangOpts.OpenMP) ||
2020	DeclsToCheckForDeferredDiags.empty())
2021	return;
2022
2023	DeferredDiagnosticsEmitter DDE(*this);
2024	for (auto *D : DeclsToCheckForDeferredDiags)
2025	DDE.checkRecordedDecl(D);
2026	}
2027
2028	// In CUDA, there are some constructs which may appear in semantically-valid
2029	// code, but trigger errors if we ever generate code for the function in which
2030	// they appear. Essentially every construct you're not allowed to use on the
2031	// device falls into this category, because you are allowed to use these
2032	// constructs in a __host__ __device__ function, but only if that function is
2033	// never codegen'ed on the device.
2034	//
2035	// To handle semantic checking for these constructs, we keep track of the set of
2036	// functions we know will be emitted, either because we could tell a priori that
2037	// they would be emitted, or because they were transitively called by a
2038	// known-emitted function.
2039	//
2040	// We also keep a partial call graph of which not-known-emitted functions call
2041	// which other not-known-emitted functions.
2042	//
2043	// When we see something which is illegal if the current function is emitted
2044	// (usually by way of DiagIfDeviceCode, DiagIfHostCode, or
2045	// CheckCall), we first check if the current function is known-emitted. If
2046	// so, we immediately output the diagnostic.
2047	//
2048	// Otherwise, we "defer" the diagnostic. It sits in Sema::DeviceDeferredDiags
2049	// until we discover that the function is known-emitted, at which point we take
2050	// it out of this map and emit the diagnostic.
2051
2052	Sema::SemaDiagnosticBuilder::SemaDiagnosticBuilder(Kind K, SourceLocation Loc,
2053	unsigned DiagID,
2054	const FunctionDecl *Fn,
2055	Sema &S)
2056	: S(S), Loc(Loc), DiagID(DiagID), Fn(Fn),
2057	ShowCallStack(K == K_ImmediateWithCallStack || K == K_Deferred) {
2058	switch (K) {
2059	case K_Nop:
2060	break;
2061	case K_Immediate:
2062	case K_ImmediateWithCallStack:
2063	ImmediateDiag.emplace(
2064	args: ImmediateDiagBuilder(S.Diags.Report(Loc, DiagID), S, DiagID));
2065	break;
2066	case K_Deferred:
2067	assert(Fn && "Must have a function to attach the deferred diag to.");
2068	auto &Diags = S.DeviceDeferredDiags[Fn];
2069	PartialDiagId.emplace(args: Diags.size());
2070	Diags.emplace_back(Loc, S.PDiag(DiagID));
2071	break;
2072	}
2073	}
2074
2075	Sema::SemaDiagnosticBuilder::SemaDiagnosticBuilder(SemaDiagnosticBuilder &&D)
2076	: S(D.S), Loc(D.Loc), DiagID(D.DiagID), Fn(D.Fn),
2077	ShowCallStack(D.ShowCallStack), ImmediateDiag(D.ImmediateDiag),
2078	PartialDiagId(D.PartialDiagId) {
2079	// Clean the previous diagnostics.
2080	D.ShowCallStack = false;
2081	D.ImmediateDiag.reset();
2082	D.PartialDiagId.reset();
2083	}
2084
2085	Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() {
2086	if (ImmediateDiag) {
2087	// Emit our diagnostic and, if it was a warning or error, output a callstack
2088	// if Fn isn't a priori known-emitted.
2089	ImmediateDiag.reset(); // Emit the immediate diag.
2090
2091	if (ShowCallStack) {
2092	bool IsWarningOrError = S.getDiagnostics().getDiagnosticLevel(
2093	DiagID, Loc) >= DiagnosticsEngine::Warning;
2094	if (IsWarningOrError)
2095	emitCallStackNotes(S, FD: Fn);
2096	}
2097	} else {
2098	assert((!PartialDiagId || ShowCallStack) &&
2099	"Must always show call stack for deferred diags.");
2100	}
2101	}
2102
2103	Sema::SemaDiagnosticBuilder
2104	Sema::targetDiag(SourceLocation Loc, unsigned DiagID, const FunctionDecl *FD) {
2105	FD = FD ? FD : getCurFunctionDecl();
2106	if (LangOpts.OpenMP)
2107	return LangOpts.OpenMPIsTargetDevice
2108	? OpenMP().diagIfOpenMPDeviceCode(Loc, DiagID, FD)
2109	: OpenMP().diagIfOpenMPHostCode(Loc, DiagID, FD);
2110	if (getLangOpts().CUDA)
2111	return getLangOpts().CUDAIsDevice ? CUDA().DiagIfDeviceCode(Loc, DiagID)
2112	: CUDA().DiagIfHostCode(Loc, DiagID);
2113
2114	if (getLangOpts().SYCLIsDevice)
2115	return SYCL().DiagIfDeviceCode(Loc, DiagID);
2116
2117	return SemaDiagnosticBuilder(SemaDiagnosticBuilder::K_Immediate, Loc, DiagID,
2118	FD, *this);
2119	}
2120
2121	void Sema::checkTypeSupport(QualType Ty, SourceLocation Loc, ValueDecl *D) {
2122	if (isUnevaluatedContext() || Ty.isNull())
2123	return;
2124
2125	// The original idea behind checkTypeSupport function is that unused
2126	// declarations can be replaced with an array of bytes of the same size during
2127	// codegen, such replacement doesn't seem to be possible for types without
2128	// constant byte size like zero length arrays. So, do a deep check for SYCL.
2129	if (D && LangOpts.SYCLIsDevice) {
2130	llvm::DenseSet<QualType> Visited;
2131	SYCL().deepTypeCheckForDevice(UsedAt: Loc, Visited, DeclToCheck: D);
2132	}
2133
2134	Decl *C = cast<Decl>(Val: getCurLexicalContext());
2135
2136	// Memcpy operations for structs containing a member with unsupported type
2137	// are ok, though.
2138	if (const auto *MD = dyn_cast<CXXMethodDecl>(Val: C)) {
2139	if ((MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) &&
2140	MD->isTrivial())
2141	return;
2142
2143	if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(Val: MD))
2144	if (Ctor->isCopyOrMoveConstructor() && Ctor->isTrivial())
2145	return;
2146	}
2147
2148	// Try to associate errors with the lexical context, if that is a function, or
2149	// the value declaration otherwise.
2150	const FunctionDecl *FD = isa<FunctionDecl>(Val: C)
2151	? cast<FunctionDecl>(Val: C)
2152	: dyn_cast_or_null<FunctionDecl>(Val: D);
2153
2154	auto CheckDeviceType = [&](QualType Ty) {
2155	if (Ty->isDependentType())
2156	return;
2157
2158	if (Ty->isBitIntType()) {
2159	if (!Context.getTargetInfo().hasBitIntType()) {
2160	PartialDiagnostic PD = PDiag(diag::err_target_unsupported_type);
2161	if (D)
2162	PD << D;
2163	else
2164	PD << "expression";
2165	targetDiag(Loc, PD, FD)
2166	<< false /*show bit size*/ << 0 /*bitsize*/ << false /*return*/
2167	<< Ty << Context.getTargetInfo().getTriple().str();
2168	}
2169	return;
2170	}
2171
2172	// Check if we are dealing with two 'long double' but with different
2173	// semantics.
2174	bool LongDoubleMismatched = false;
2175	if (Ty->isRealFloatingType() && Context.getTypeSize(T: Ty) == 128) {
2176	const llvm::fltSemantics &Sem = Context.getFloatTypeSemantics(T: Ty);
2177	if ((&Sem != &llvm::APFloat::PPCDoubleDouble() &&
2178	!Context.getTargetInfo().hasFloat128Type()) ||
2179	(&Sem == &llvm::APFloat::PPCDoubleDouble() &&
2180	!Context.getTargetInfo().hasIbm128Type()))
2181	LongDoubleMismatched = true;
2182	}
2183
2184	if ((Ty->isFloat16Type() && !Context.getTargetInfo().hasFloat16Type()) ||
2185	(Ty->isFloat128Type() && !Context.getTargetInfo().hasFloat128Type()) ||
2186	(Ty->isIbm128Type() && !Context.getTargetInfo().hasIbm128Type()) ||
2187	(Ty->isIntegerType() && Context.getTypeSize(T: Ty) == 128 &&
2188	!Context.getTargetInfo().hasInt128Type()) ||
2189	(Ty->isBFloat16Type() && !Context.getTargetInfo().hasBFloat16Type() &&
2190	!LangOpts.CUDAIsDevice) ||
2191	LongDoubleMismatched) {
2192	PartialDiagnostic PD = PDiag(diag::err_target_unsupported_type);
2193	if (D)
2194	PD << D;
2195	else
2196	PD << "expression";
2197
2198	if (targetDiag(Loc, PD, FD)
2199	<< true /*show bit size*/
2200	<< static_cast<unsigned>(Context.getTypeSize(T: Ty)) << Ty
2201	<< false /*return*/ << Context.getTargetInfo().getTriple().str()) {
2202	if (D)
2203	D->setInvalidDecl();
2204	}
2205	if (D)
2206	targetDiag(D->getLocation(), diag::note_defined_here, FD) << D;
2207	}
2208	};
2209
2210	auto CheckType = [&](QualType Ty, bool IsRetTy = false) {
2211	if (LangOpts.SYCLIsDevice ||
2212	(LangOpts.OpenMP && LangOpts.OpenMPIsTargetDevice) ||
2213	LangOpts.CUDAIsDevice)
2214	CheckDeviceType(Ty);
2215
2216	QualType UnqualTy = Ty.getCanonicalType().getUnqualifiedType();
2217	const TargetInfo &TI = Context.getTargetInfo();
2218	if (!TI.hasLongDoubleType() && UnqualTy == Context.LongDoubleTy) {
2219	PartialDiagnostic PD = PDiag(diag::err_target_unsupported_type);
2220	if (D)
2221	PD << D;
2222	else
2223	PD << "expression";
2224
2225	if (Diag(Loc, PD, FD)
2226	<< false /*show bit size*/ << 0 << Ty << false /*return*/
2227	<< TI.getTriple().str()) {
2228	if (D)
2229	D->setInvalidDecl();
2230	}
2231	if (D)
2232	targetDiag(D->getLocation(), diag::note_defined_here, FD) << D;
2233	}
2234
2235	bool IsDouble = UnqualTy == Context.DoubleTy;
2236	bool IsFloat = UnqualTy == Context.FloatTy;
2237	if (IsRetTy && !TI.hasFPReturn() && (IsDouble || IsFloat)) {
2238	PartialDiagnostic PD = PDiag(diag::err_target_unsupported_type);
2239	if (D)
2240	PD << D;
2241	else
2242	PD << "expression";
2243
2244	if (Diag(Loc, PD, FD)
2245	<< false /*show bit size*/ << 0 << Ty << true /*return*/
2246	<< TI.getTriple().str()) {
2247	if (D)
2248	D->setInvalidDecl();
2249	}
2250	if (D)
2251	targetDiag(D->getLocation(), diag::note_defined_here, FD) << D;
2252	}
2253
2254	if (TI.hasRISCVVTypes() && Ty->isRVVSizelessBuiltinType() && FD) {
2255	llvm::StringMap<bool> CallerFeatureMap;
2256	Context.getFunctionFeatureMap(CallerFeatureMap, FD);
2257	RISCV().checkRVVTypeSupport(Ty, Loc, D, CallerFeatureMap);
2258	}
2259
2260	// Don't allow SVE types in functions without a SVE target.
2261	if (Ty->isSVESizelessBuiltinType() && FD) {
2262	llvm::StringMap<bool> CallerFeatureMap;
2263	Context.getFunctionFeatureMap(CallerFeatureMap, FD);
2264	if (!Builtin::evaluateRequiredTargetFeatures("sve", CallerFeatureMap)) {
2265	if (!Builtin::evaluateRequiredTargetFeatures("sme", CallerFeatureMap))
2266	Diag(Loc, diag::err_sve_vector_in_non_sve_target) << Ty;
2267	else if (!IsArmStreamingFunction(FD,
2268	/*IncludeLocallyStreaming=*/true)) {
2269	Diag(Loc, diag::err_sve_vector_in_non_streaming_function) << Ty;
2270	}
2271	}
2272	}
2273	};
2274
2275	CheckType(Ty);
2276	if (const auto *FPTy = dyn_cast<FunctionProtoType>(Val&: Ty)) {
2277	for (const auto &ParamTy : FPTy->param_types())
2278	CheckType(ParamTy);
2279	CheckType(FPTy->getReturnType(), /*IsRetTy=*/true);
2280	}
2281	if (const auto *FNPTy = dyn_cast<FunctionNoProtoType>(Val&: Ty))
2282	CheckType(FNPTy->getReturnType(), /*IsRetTy=*/true);
2283	}
2284
2285	bool Sema::findMacroSpelling(SourceLocation &locref, StringRef name) {
2286	SourceLocation loc = locref;
2287	if (!loc.isMacroID()) return false;
2288
2289	// There's no good way right now to look at the intermediate
2290	// expansions, so just jump to the expansion location.
2291	loc = getSourceManager().getExpansionLoc(Loc: loc);
2292
2293	// If that's written with the name, stop here.
2294	SmallString<16> buffer;
2295	if (getPreprocessor().getSpelling(loc, buffer) == name) {
2296	locref = loc;
2297	return true;
2298	}
2299	return false;
2300	}
2301
2302	Scope *Sema::getScopeForContext(DeclContext *Ctx) {
2303
2304	if (!Ctx)
2305	return nullptr;
2306
2307	Ctx = Ctx->getPrimaryContext();
2308	for (Scope *S = getCurScope(); S; S = S->getParent()) {
2309	// Ignore scopes that cannot have declarations. This is important for
2310	// out-of-line definitions of static class members.
2311	if (S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope))
2312	if (DeclContext *Entity = S->getEntity())
2313	if (Ctx == Entity->getPrimaryContext())
2314	return S;
2315	}
2316
2317	return nullptr;
2318	}
2319
2320	/// Enter a new function scope
2321	void Sema::PushFunctionScope() {
2322	if (FunctionScopes.empty() && CachedFunctionScope) {
2323	// Use CachedFunctionScope to avoid allocating memory when possible.
2324	CachedFunctionScope->Clear();
2325	FunctionScopes.push_back(Elt: CachedFunctionScope.release());
2326	} else {
2327	FunctionScopes.push_back(Elt: new FunctionScopeInfo(getDiagnostics()));
2328	}
2329	if (LangOpts.OpenMP)
2330	OpenMP().pushOpenMPFunctionRegion();
2331	}
2332
2333	void Sema::PushBlockScope(Scope *BlockScope, BlockDecl *Block) {
2334	FunctionScopes.push_back(new BlockScopeInfo(getDiagnostics(),
2335	BlockScope, Block));
2336	CapturingFunctionScopes++;
2337	}
2338
2339	LambdaScopeInfo *Sema::PushLambdaScope() {
2340	LambdaScopeInfo *const LSI = new LambdaScopeInfo(getDiagnostics());
2341	FunctionScopes.push_back(LSI);
2342	CapturingFunctionScopes++;
2343	return LSI;
2344	}
2345
2346	void Sema::RecordParsingTemplateParameterDepth(unsigned Depth) {
2347	if (LambdaScopeInfo *const LSI = getCurLambda()) {
2348	LSI->AutoTemplateParameterDepth = Depth;
2349	return;
2350	}
2351	llvm_unreachable(
2352	"Remove assertion if intentionally called in a non-lambda context.");
2353	}
2354
2355	// Check that the type of the VarDecl has an accessible copy constructor and
2356	// resolve its destructor's exception specification.
2357	// This also performs initialization of block variables when they are moved
2358	// to the heap. It uses the same rules as applicable for implicit moves
2359	// according to the C++ standard in effect ([class.copy.elision]p3).
2360	static void checkEscapingByref(VarDecl *VD, Sema &S) {
2361	QualType T = VD->getType();
2362	EnterExpressionEvaluationContext scope(
2363	S, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
2364	SourceLocation Loc = VD->getLocation();
2365	Expr *VarRef =
2366	new (S.Context) DeclRefExpr(S.Context, VD, false, T, VK_LValue, Loc);
2367	ExprResult Result;
2368	auto IE = InitializedEntity::InitializeBlock(BlockVarLoc: Loc, Type: T);
2369	if (S.getLangOpts().CPlusPlus23) {
2370	auto *E = ImplicitCastExpr::Create(Context: S.Context, T, Kind: CK_NoOp, Operand: VarRef, BasePath: nullptr,
2371	Cat: VK_XValue, FPO: FPOptionsOverride());
2372	Result = S.PerformCopyInitialization(Entity: IE, EqualLoc: SourceLocation(), Init: E);
2373	} else {
2374	Result = S.PerformMoveOrCopyInitialization(
2375	Entity: IE, NRInfo: Sema::NamedReturnInfo{.Candidate: VD, .S: Sema::NamedReturnInfo::MoveEligible},
2376	Value: VarRef);
2377	}
2378
2379	if (!Result.isInvalid()) {
2380	Result = S.MaybeCreateExprWithCleanups(SubExpr: Result);
2381	Expr *Init = Result.getAs<Expr>();
2382	S.Context.setBlockVarCopyInit(VD, CopyExpr: Init, CanThrow: S.canThrow(Init));
2383	}
2384
2385	// The destructor's exception specification is needed when IRGen generates
2386	// block copy/destroy functions. Resolve it here.
2387	if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
2388	if (CXXDestructorDecl *DD = RD->getDestructor()) {
2389	auto *FPT = DD->getType()->castAs<FunctionProtoType>();
2390	S.ResolveExceptionSpec(Loc, FPT: FPT);
2391	}
2392	}
2393
2394	static void markEscapingByrefs(const FunctionScopeInfo &FSI, Sema &S) {
2395	// Set the EscapingByref flag of __block variables captured by
2396	// escaping blocks.
2397	for (const BlockDecl *BD : FSI.Blocks) {
2398	for (const BlockDecl::Capture &BC : BD->captures()) {
2399	VarDecl *VD = BC.getVariable();
2400	if (VD->hasAttr<BlocksAttr>()) {
2401	// Nothing to do if this is a __block variable captured by a
2402	// non-escaping block.
2403	if (BD->doesNotEscape())
2404	continue;
2405	VD->setEscapingByref();
2406	}
2407	// Check whether the captured variable is or contains an object of
2408	// non-trivial C union type.
2409	QualType CapType = BC.getVariable()->getType();
2410	if (CapType.hasNonTrivialToPrimitiveDestructCUnion() ||
2411	CapType.hasNonTrivialToPrimitiveCopyCUnion())
2412	S.checkNonTrivialCUnion(QT: BC.getVariable()->getType(),
2413	Loc: BD->getCaretLocation(),
2414	UseContext: NonTrivialCUnionContext::BlockCapture,
2415	NonTrivialKind: Sema::NTCUK_Destruct | Sema::NTCUK_Copy);
2416	}
2417	}
2418
2419	for (VarDecl *VD : FSI.ByrefBlockVars) {
2420	// __block variables might require us to capture a copy-initializer.
2421	if (!VD->isEscapingByref())
2422	continue;
2423	// It's currently invalid to ever have a __block variable with an
2424	// array type; should we diagnose that here?
2425	// Regardless, we don't want to ignore array nesting when
2426	// constructing this copy.
2427	if (VD->getType()->isStructureOrClassType())
2428	checkEscapingByref(VD, S);
2429	}
2430	}
2431
2432	Sema::PoppedFunctionScopePtr
2433	Sema::PopFunctionScopeInfo(const AnalysisBasedWarnings::Policy *WP,
2434	const Decl *D, QualType BlockType) {
2435	assert(!FunctionScopes.empty() && "mismatched push/pop!");
2436
2437	markEscapingByrefs(FSI: *FunctionScopes.back(), S&: *this);
2438
2439	PoppedFunctionScopePtr Scope(FunctionScopes.pop_back_val(),
2440	PoppedFunctionScopeDeleter(this));
2441
2442	if (LangOpts.OpenMP)
2443	OpenMP().popOpenMPFunctionRegion(OldFSI: Scope.get());
2444
2445	// Issue any analysis-based warnings.
2446	if (WP && D)
2447	AnalysisWarnings.IssueWarnings(P: *WP, fscope: Scope.get(), D, BlockType);
2448	else
2449	for (const auto &PUD : Scope->PossiblyUnreachableDiags)
2450	Diag(PUD.Loc, PUD.PD);
2451
2452	return Scope;
2453	}
2454
2455	void Sema::PoppedFunctionScopeDeleter::
2456	operator()(sema::FunctionScopeInfo *Scope) const {
2457	if (!Scope->isPlainFunction())
2458	Self->CapturingFunctionScopes--;
2459	// Stash the function scope for later reuse if it's for a normal function.
2460	if (Scope->isPlainFunction() && !Self->CachedFunctionScope)
2461	Self->CachedFunctionScope.reset(p: Scope);
2462	else
2463	delete Scope;
2464	}
2465
2466	void Sema::PushCompoundScope(bool IsStmtExpr) {
2467	getCurFunction()->CompoundScopes.push_back(
2468	Elt: CompoundScopeInfo(IsStmtExpr, getCurFPFeatures()));
2469	}
2470
2471	void Sema::PopCompoundScope() {
2472	FunctionScopeInfo *CurFunction = getCurFunction();
2473	assert(!CurFunction->CompoundScopes.empty() && "mismatched push/pop");
2474
2475	CurFunction->CompoundScopes.pop_back();
2476	}
2477
2478	bool Sema::hasAnyUnrecoverableErrorsInThisFunction() const {
2479	return getCurFunction()->hasUnrecoverableErrorOccurred();
2480	}
2481
2482	void Sema::setFunctionHasBranchIntoScope() {
2483	if (!FunctionScopes.empty())
2484	FunctionScopes.back()->setHasBranchIntoScope();
2485	}
2486
2487	void Sema::setFunctionHasBranchProtectedScope() {
2488	if (!FunctionScopes.empty())
2489	FunctionScopes.back()->setHasBranchProtectedScope();
2490	}
2491
2492	void Sema::setFunctionHasIndirectGoto() {
2493	if (!FunctionScopes.empty())
2494	FunctionScopes.back()->setHasIndirectGoto();
2495	}
2496
2497	void Sema::setFunctionHasMustTail() {
2498	if (!FunctionScopes.empty())
2499	FunctionScopes.back()->setHasMustTail();
2500	}
2501
2502	BlockScopeInfo *Sema::getCurBlock() {
2503	if (FunctionScopes.empty())
2504	return nullptr;
2505
2506	auto CurBSI = dyn_cast<BlockScopeInfo>(Val: FunctionScopes.back());
2507	if (CurBSI && CurBSI->TheDecl &&
2508	!CurBSI->TheDecl->Encloses(CurContext)) {
2509	// We have switched contexts due to template instantiation.
2510	assert(!CodeSynthesisContexts.empty());
2511	return nullptr;
2512	}
2513
2514	return CurBSI;
2515	}
2516
2517	FunctionScopeInfo *Sema::getEnclosingFunction() const {
2518	if (FunctionScopes.empty())
2519	return nullptr;
2520
2521	for (int e = FunctionScopes.size() - 1; e >= 0; --e) {
2522	if (isa<sema::BlockScopeInfo>(Val: FunctionScopes[e]))
2523	continue;
2524	return FunctionScopes[e];
2525	}
2526	return nullptr;
2527	}
2528
2529	CapturingScopeInfo *Sema::getEnclosingLambdaOrBlock() const {
2530	for (auto *Scope : llvm::reverse(C: FunctionScopes)) {
2531	if (auto *CSI = dyn_cast<CapturingScopeInfo>(Val: Scope)) {
2532	auto *LSI = dyn_cast<LambdaScopeInfo>(Val: CSI);
2533	if (LSI && LSI->Lambda && !LSI->Lambda->Encloses(CurContext) &&
2534	LSI->AfterParameterList) {
2535	// We have switched contexts due to template instantiation.
2536	// FIXME: We should swap out the FunctionScopes during code synthesis
2537	// so that we don't need to check for this.
2538	assert(!CodeSynthesisContexts.empty());
2539	return nullptr;
2540	}
2541	return CSI;
2542	}
2543	}
2544	return nullptr;
2545	}
2546
2547	LambdaScopeInfo *Sema::getCurLambda(bool IgnoreNonLambdaCapturingScope) {
2548	if (FunctionScopes.empty())
2549	return nullptr;
2550
2551	auto I = FunctionScopes.rbegin();
2552	if (IgnoreNonLambdaCapturingScope) {
2553	auto E = FunctionScopes.rend();
2554	while (I != E && isa<CapturingScopeInfo>(Val: *I) && !isa<LambdaScopeInfo>(Val: *I))
2555	++I;
2556	if (I == E)
2557	return nullptr;
2558	}
2559	auto *CurLSI = dyn_cast<LambdaScopeInfo>(Val: *I);
2560	if (CurLSI && CurLSI->Lambda && CurLSI->CallOperator &&
2561	!CurLSI->Lambda->Encloses(CurContext) && CurLSI->AfterParameterList) {
2562	// We have switched contexts due to template instantiation.
2563	assert(!CodeSynthesisContexts.empty());
2564	return nullptr;
2565	}
2566
2567	return CurLSI;
2568	}
2569
2570	// We have a generic lambda if we parsed auto parameters, or we have
2571	// an associated template parameter list.
2572	LambdaScopeInfo *Sema::getCurGenericLambda() {
2573	if (LambdaScopeInfo *LSI = getCurLambda()) {
2574	return (LSI->TemplateParams.size() ||
2575	LSI->GLTemplateParameterList) ? LSI : nullptr;
2576	}
2577	return nullptr;
2578	}
2579
2580
2581	void Sema::ActOnComment(SourceRange Comment) {
2582	if (!LangOpts.RetainCommentsFromSystemHeaders &&
2583	SourceMgr.isInSystemHeader(Loc: Comment.getBegin()))
2584	return;
2585	RawComment RC(SourceMgr, Comment, LangOpts.CommentOpts, false);
2586	if (RC.isAlmostTrailingComment() || RC.hasUnsupportedSplice(SourceMgr)) {
2587	SourceRange MagicMarkerRange(Comment.getBegin(),
2588	Comment.getBegin().getLocWithOffset(Offset: 3));
2589	StringRef MagicMarkerText;
2590	switch (RC.getKind()) {
2591	case RawComment::RCK_OrdinaryBCPL:
2592	MagicMarkerText = "///<";
2593	break;
2594	case RawComment::RCK_OrdinaryC:
2595	MagicMarkerText = "/**<";
2596	break;
2597	case RawComment::RCK_Invalid:
2598	// FIXME: are there other scenarios that could produce an invalid
2599	// raw comment here?
2600	Diag(Comment.getBegin(), diag::warn_splice_in_doxygen_comment);
2601	return;
2602	default:
2603	llvm_unreachable("if this is an almost Doxygen comment, "
2604	"it should be ordinary");
2605	}
2606	Diag(Comment.getBegin(), diag::warn_not_a_doxygen_trailing_member_comment) <<
2607	FixItHint::CreateReplacement(MagicMarkerRange, MagicMarkerText);
2608	}
2609	Context.addComment(RC);
2610	}
2611
2612	// Pin this vtable to this file.
2613	ExternalSemaSource::~ExternalSemaSource() {}
2614	char ExternalSemaSource::ID;
2615
2616	void ExternalSemaSource::ReadMethodPool(Selector Sel) { }
2617	void ExternalSemaSource::updateOutOfDateSelector(Selector Sel) { }
2618
2619	void ExternalSemaSource::ReadKnownNamespaces(
2620	SmallVectorImpl<NamespaceDecl *> &Namespaces) {
2621	}
2622
2623	void ExternalSemaSource::ReadUndefinedButUsed(
2624	llvm::MapVector<NamedDecl *, SourceLocation> &Undefined) {}
2625
2626	void ExternalSemaSource::ReadMismatchingDeleteExpressions(llvm::MapVector<
2627	FieldDecl *, llvm::SmallVector<std::pair<SourceLocation, bool>, 4>> &) {}
2628
2629	bool Sema::tryExprAsCall(Expr &E, QualType &ZeroArgCallReturnTy,
2630	UnresolvedSetImpl &OverloadSet) {
2631	ZeroArgCallReturnTy = QualType();
2632	OverloadSet.clear();
2633
2634	const OverloadExpr *Overloads = nullptr;
2635	bool IsMemExpr = false;
2636	if (E.getType() == Context.OverloadTy) {
2637	OverloadExpr::FindResult FR = OverloadExpr::find(E: &E);
2638
2639	// Ignore overloads that are pointer-to-member constants.
2640	if (FR.HasFormOfMemberPointer)
2641	return false;
2642
2643	Overloads = FR.Expression;
2644	} else if (E.getType() == Context.BoundMemberTy) {
2645	Overloads = dyn_cast<UnresolvedMemberExpr>(Val: E.IgnoreParens());
2646	IsMemExpr = true;
2647	}
2648
2649	bool Ambiguous = false;
2650	bool IsMV = false;
2651
2652	if (Overloads) {
2653	for (OverloadExpr::decls_iterator it = Overloads->decls_begin(),
2654	DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) {
2655	OverloadSet.addDecl(D: *it);
2656
2657	// Check whether the function is a non-template, non-member which takes no
2658	// arguments.
2659	if (IsMemExpr)
2660	continue;
2661	if (const FunctionDecl *OverloadDecl
2662	= dyn_cast<FunctionDecl>(Val: (*it)->getUnderlyingDecl())) {
2663	if (OverloadDecl->getMinRequiredArguments() == 0) {
2664	if (!ZeroArgCallReturnTy.isNull() && !Ambiguous &&
2665	(!IsMV || !(OverloadDecl->isCPUDispatchMultiVersion() ||
2666	OverloadDecl->isCPUSpecificMultiVersion()))) {
2667	ZeroArgCallReturnTy = QualType();
2668	Ambiguous = true;
2669	} else {
2670	ZeroArgCallReturnTy = OverloadDecl->getReturnType();
2671	IsMV = OverloadDecl->isCPUDispatchMultiVersion() ||
2672	OverloadDecl->isCPUSpecificMultiVersion();
2673	}
2674	}
2675	}
2676	}
2677
2678	// If it's not a member, use better machinery to try to resolve the call
2679	if (!IsMemExpr)
2680	return !ZeroArgCallReturnTy.isNull();
2681	}
2682
2683	// Attempt to call the member with no arguments - this will correctly handle
2684	// member templates with defaults/deduction of template arguments, overloads
2685	// with default arguments, etc.
2686	if (IsMemExpr && !E.isTypeDependent()) {
2687	Sema::TentativeAnalysisScope Trap(*this);
2688	ExprResult R = BuildCallToMemberFunction(S: nullptr, MemExpr: &E, LParenLoc: SourceLocation(), Args: {},
2689	RParenLoc: SourceLocation());
2690	if (R.isUsable()) {
2691	ZeroArgCallReturnTy = R.get()->getType();
2692	return true;
2693	}
2694	return false;
2695	}
2696
2697	if (const auto *DeclRef = dyn_cast<DeclRefExpr>(Val: E.IgnoreParens())) {
2698	if (const auto *Fun = dyn_cast<FunctionDecl>(Val: DeclRef->getDecl())) {
2699	if (Fun->getMinRequiredArguments() == 0)
2700	ZeroArgCallReturnTy = Fun->getReturnType();
2701	return true;
2702	}
2703	}
2704
2705	// We don't have an expression that's convenient to get a FunctionDecl from,
2706	// but we can at least check if the type is "function of 0 arguments".
2707	QualType ExprTy = E.getType();
2708	const FunctionType *FunTy = nullptr;
2709	QualType PointeeTy = ExprTy->getPointeeType();
2710	if (!PointeeTy.isNull())
2711	FunTy = PointeeTy->getAs<FunctionType>();
2712	if (!FunTy)
2713	FunTy = ExprTy->getAs<FunctionType>();
2714
2715	if (const auto *FPT = dyn_cast_if_present<FunctionProtoType>(Val: FunTy)) {
2716	if (FPT->getNumParams() == 0)
2717	ZeroArgCallReturnTy = FunTy->getReturnType();
2718	return true;
2719	}
2720	return false;
2721	}
2722
2723	/// Give notes for a set of overloads.
2724	///
2725	/// A companion to tryExprAsCall. In cases when the name that the programmer
2726	/// wrote was an overloaded function, we may be able to make some guesses about
2727	/// plausible overloads based on their return types; such guesses can be handed
2728	/// off to this method to be emitted as notes.
2729	///
2730	/// \param Overloads - The overloads to note.
2731	/// \param FinalNoteLoc - If we've suppressed printing some overloads due to
2732	/// -fshow-overloads=best, this is the location to attach to the note about too
2733	/// many candidates. Typically this will be the location of the original
2734	/// ill-formed expression.
2735	static void noteOverloads(Sema &S, const UnresolvedSetImpl &Overloads,
2736	const SourceLocation FinalNoteLoc) {
2737	unsigned ShownOverloads = 0;
2738	unsigned SuppressedOverloads = 0;
2739	for (UnresolvedSetImpl::iterator It = Overloads.begin(),
2740	DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
2741	if (ShownOverloads >= S.Diags.getNumOverloadCandidatesToShow()) {
2742	++SuppressedOverloads;
2743	continue;
2744	}
2745
2746	const NamedDecl *Fn = (*It)->getUnderlyingDecl();
2747	// Don't print overloads for non-default multiversioned functions.
2748	if (const auto *FD = Fn->getAsFunction()) {
2749	if (FD->isMultiVersion() && FD->hasAttr<TargetAttr>() &&
2750	!FD->getAttr<TargetAttr>()->isDefaultVersion())
2751	continue;
2752	if (FD->isMultiVersion() && FD->hasAttr<TargetVersionAttr>() &&
2753	!FD->getAttr<TargetVersionAttr>()->isDefaultVersion())
2754	continue;
2755	}
2756	S.Diag(Fn->getLocation(), diag::note_possible_target_of_call);
2757	++ShownOverloads;
2758	}
2759
2760	S.Diags.overloadCandidatesShown(N: ShownOverloads);
2761
2762	if (SuppressedOverloads)
2763	S.Diag(FinalNoteLoc, diag::note_ovl_too_many_candidates)
2764	<< SuppressedOverloads;
2765	}
2766
2767	static void notePlausibleOverloads(Sema &S, SourceLocation Loc,
2768	const UnresolvedSetImpl &Overloads,
2769	bool (*IsPlausibleResult)(QualType)) {
2770	if (!IsPlausibleResult)
2771	return noteOverloads(S, Overloads, FinalNoteLoc: Loc);
2772
2773	UnresolvedSet<2> PlausibleOverloads;
2774	for (OverloadExpr::decls_iterator It = Overloads.begin(),
2775	DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
2776	const auto *OverloadDecl = cast<FunctionDecl>(Val: *It);
2777	QualType OverloadResultTy = OverloadDecl->getReturnType();
2778	if (IsPlausibleResult(OverloadResultTy))
2779	PlausibleOverloads.addDecl(D: It.getDecl());
2780	}
2781	noteOverloads(S, Overloads: PlausibleOverloads, FinalNoteLoc: Loc);
2782	}
2783
2784	/// Determine whether the given expression can be called by just
2785	/// putting parentheses after it. Notably, expressions with unary
2786	/// operators can't be because the unary operator will start parsing
2787	/// outside the call.
2788	static bool IsCallableWithAppend(const Expr *E) {
2789	E = E->IgnoreImplicit();
2790	return (!isa<CStyleCastExpr>(Val: E) &&
2791	!isa<UnaryOperator>(Val: E) &&
2792	!isa<BinaryOperator>(Val: E) &&
2793	!isa<CXXOperatorCallExpr>(Val: E));
2794	}
2795
2796	static bool IsCPUDispatchCPUSpecificMultiVersion(const Expr *E) {
2797	if (const auto *UO = dyn_cast<UnaryOperator>(Val: E))
2798	E = UO->getSubExpr();
2799
2800	if (const auto *ULE = dyn_cast<UnresolvedLookupExpr>(Val: E)) {
2801	if (ULE->getNumDecls() == 0)
2802	return false;
2803
2804	const NamedDecl *ND = *ULE->decls_begin();
2805	if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2806	return FD->isCPUDispatchMultiVersion() || FD->isCPUSpecificMultiVersion();
2807	}
2808	return false;
2809	}
2810
2811	bool Sema::tryToRecoverWithCall(ExprResult &E, const PartialDiagnostic &PD,
2812	bool ForceComplain,
2813	bool (*IsPlausibleResult)(QualType)) {
2814	SourceLocation Loc = E.get()->getExprLoc();
2815	SourceRange Range = E.get()->getSourceRange();
2816	UnresolvedSet<4> Overloads;
2817
2818	// If this is a SFINAE context, don't try anything that might trigger ADL
2819	// prematurely.
2820	if (!isSFINAEContext()) {
2821	QualType ZeroArgCallTy;
2822	if (tryExprAsCall(E&: *E.get(), ZeroArgCallReturnTy&: ZeroArgCallTy, OverloadSet&: Overloads) &&
2823	!ZeroArgCallTy.isNull() &&
2824	(!IsPlausibleResult || IsPlausibleResult(ZeroArgCallTy))) {
2825	// At this point, we know E is potentially callable with 0
2826	// arguments and that it returns something of a reasonable type,
2827	// so we can emit a fixit and carry on pretending that E was
2828	// actually a CallExpr.
2829	SourceLocation ParenInsertionLoc = getLocForEndOfToken(Loc: Range.getEnd());
2830	bool IsMV = IsCPUDispatchCPUSpecificMultiVersion(E: E.get());
2831	Diag(Loc, PD) << /*zero-arg*/ 1 << IsMV << Range
2832	<< (IsCallableWithAppend(E: E.get())
2833	? FixItHint::CreateInsertion(InsertionLoc: ParenInsertionLoc,
2834	Code: "()")
2835	: FixItHint());
2836	if (!IsMV)
2837	notePlausibleOverloads(S&: *this, Loc, Overloads, IsPlausibleResult);
2838
2839	// FIXME: Try this before emitting the fixit, and suppress diagnostics
2840	// while doing so.
2841	E = BuildCallExpr(S: nullptr, Fn: E.get(), LParenLoc: Range.getEnd(), ArgExprs: {},
2842	RParenLoc: Range.getEnd().getLocWithOffset(Offset: 1));
2843	return true;
2844	}
2845	}
2846	if (!ForceComplain) return false;
2847
2848	bool IsMV = IsCPUDispatchCPUSpecificMultiVersion(E: E.get());
2849	Diag(Loc, PD) << /*not zero-arg*/ 0 << IsMV << Range;
2850	if (!IsMV)
2851	notePlausibleOverloads(S&: *this, Loc, Overloads, IsPlausibleResult);
2852	E = ExprError();
2853	return true;
2854	}
2855
2856	IdentifierInfo *Sema::getSuperIdentifier() const {
2857	if (!Ident_super)
2858	Ident_super = &Context.Idents.get(Name: "super");
2859	return Ident_super;
2860	}
2861
2862	void Sema::PushCapturedRegionScope(Scope *S, CapturedDecl *CD, RecordDecl *RD,
2863	CapturedRegionKind K,
2864	unsigned OpenMPCaptureLevel) {
2865	auto *CSI = new CapturedRegionScopeInfo(
2866	getDiagnostics(), S, CD, RD, CD->getContextParam(), K,
2867	(getLangOpts().OpenMP && K == CR_OpenMP)
2868	? OpenMP().getOpenMPNestingLevel()
2869	: 0,
2870	OpenMPCaptureLevel);
2871	CSI->ReturnType = Context.VoidTy;
2872	FunctionScopes.push_back(CSI);
2873	CapturingFunctionScopes++;
2874	}
2875
2876	CapturedRegionScopeInfo *Sema::getCurCapturedRegion() {
2877	if (FunctionScopes.empty())
2878	return nullptr;
2879
2880	return dyn_cast<CapturedRegionScopeInfo>(Val: FunctionScopes.back());
2881	}
2882
2883	const llvm::MapVector<FieldDecl *, Sema::DeleteLocs> &
2884	Sema::getMismatchingDeleteExpressions() const {
2885	return DeleteExprs;
2886	}
2887
2888	Sema::FPFeaturesStateRAII::FPFeaturesStateRAII(Sema &S)
2889	: S(S), OldFPFeaturesState(S.CurFPFeatures),
2890	OldOverrides(S.FpPragmaStack.CurrentValue),
2891	OldEvalMethod(S.PP.getCurrentFPEvalMethod()),
2892	OldFPPragmaLocation(S.PP.getLastFPEvalPragmaLocation()) {}
2893
2894	Sema::FPFeaturesStateRAII::~FPFeaturesStateRAII() {
2895	S.CurFPFeatures = OldFPFeaturesState;
2896	S.FpPragmaStack.CurrentValue = OldOverrides;
2897	S.PP.setCurrentFPEvalMethod(PragmaLoc: OldFPPragmaLocation, Val: OldEvalMethod);
2898	}
2899
2900	bool Sema::isDeclaratorFunctionLike(Declarator &D) {
2901	assert(D.getCXXScopeSpec().isSet() &&
2902	"can only be called for qualified names");
2903
2904	auto LR = LookupResult(*this, D.getIdentifier(), D.getBeginLoc(),
2905	LookupOrdinaryName, forRedeclarationInCurContext());
2906	DeclContext *DC = computeDeclContext(SS: D.getCXXScopeSpec(),
2907	EnteringContext: !D.getDeclSpec().isFriendSpecified());
2908	if (!DC)
2909	return false;
2910
2911	LookupQualifiedName(R&: LR, LookupCtx: DC);
2912	bool Result = llvm::all_of(Range&: LR, P: [](Decl *Dcl) {
2913	if (NamedDecl *ND = dyn_cast<NamedDecl>(Val: Dcl)) {
2914	ND = ND->getUnderlyingDecl();
2915	return isa<FunctionDecl>(Val: ND) || isa<FunctionTemplateDecl>(Val: ND) ||
2916	isa<UsingDecl>(Val: ND);
2917	}
2918	return false;
2919	});
2920	return Result;
2921	}
2922
2923	Attr *Sema::CreateAnnotationAttr(const AttributeCommonInfo &CI, StringRef Annot,
2924	MutableArrayRef<Expr *> Args) {
2925
2926	auto *A = AnnotateAttr::Create(Context, Annot, Args.data(), Args.size(), CI);
2927	if (!ConstantFoldAttrArgs(
2928	CI, Args: MutableArrayRef<Expr *>(A->args_begin(), A->args_end()))) {
2929	return nullptr;
2930	}
2931	return A;
2932	}
2933
2934	Attr *Sema::CreateAnnotationAttr(const ParsedAttr &AL) {
2935	// Make sure that there is a string literal as the annotation's first
2936	// argument.
2937	StringRef Str;
2938	if (!checkStringLiteralArgumentAttr(Attr: AL, ArgNum: 0, Str))
2939	return nullptr;
2940
2941	llvm::SmallVector<Expr *, 4> Args;
2942	Args.reserve(N: AL.getNumArgs() - 1);
2943	for (unsigned Idx = 1; Idx < AL.getNumArgs(); Idx++) {
2944	assert(!AL.isArgIdent(Idx));
2945	Args.push_back(Elt: AL.getArgAsExpr(Arg: Idx));
2946	}
2947
2948	return CreateAnnotationAttr(CI: AL, Annot: Str, Args);
2949	}
2950