1	//===--- CodeGenModule.h - Per-Module state for LLVM CodeGen ----*- C++ -*-===//
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 is the internal per-translation-unit state used for llvm translation.
10	//
11	//===----------------------------------------------------------------------===//
12
13	#ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENMODULE_H
14	#define LLVM_CLANG_LIB_CODEGEN_CODEGENMODULE_H
15
16	#include "CGVTables.h"
17	#include "CodeGenTypeCache.h"
18	#include "CodeGenTypes.h"
19	#include "SanitizerMetadata.h"
20	#include "clang/AST/DeclCXX.h"
21	#include "clang/AST/DeclObjC.h"
22	#include "clang/AST/DeclOpenMP.h"
23	#include "clang/AST/GlobalDecl.h"
24	#include "clang/AST/Mangle.h"
25	#include "clang/Basic/ABI.h"
26	#include "clang/Basic/LangOptions.h"
27	#include "clang/Basic/NoSanitizeList.h"
28	#include "clang/Basic/ProfileList.h"
29	#include "clang/Basic/StackExhaustionHandler.h"
30	#include "clang/Basic/TargetInfo.h"
31	#include "clang/Basic/XRayLists.h"
32	#include "clang/Lex/PreprocessorOptions.h"
33	#include "llvm/ADT/DenseMap.h"
34	#include "llvm/ADT/MapVector.h"
35	#include "llvm/ADT/SetVector.h"
36	#include "llvm/ADT/SmallPtrSet.h"
37	#include "llvm/ADT/StringMap.h"
38	#include "llvm/IR/Module.h"
39	#include "llvm/IR/ValueHandle.h"
40	#include "llvm/Transforms/Utils/SanitizerStats.h"
41	#include <optional>
42
43	namespace llvm {
44	class Module;
45	class Constant;
46	class ConstantInt;
47	class Function;
48	class GlobalValue;
49	class DataLayout;
50	class FunctionType;
51	class LLVMContext;
52	class IndexedInstrProfReader;
53
54	namespace vfs {
55	class FileSystem;
56	}
57	}
58
59	namespace clang {
60	class ASTContext;
61	class AtomicType;
62	class FunctionDecl;
63	class IdentifierInfo;
64	class ObjCImplementationDecl;
65	class ObjCEncodeExpr;
66	class BlockExpr;
67	class CharUnits;
68	class Decl;
69	class Expr;
70	class Stmt;
71	class StringLiteral;
72	class NamedDecl;
73	class PointerAuthSchema;
74	class ValueDecl;
75	class VarDecl;
76	class LangOptions;
77	class CodeGenOptions;
78	class HeaderSearchOptions;
79	class DiagnosticsEngine;
80	class AnnotateAttr;
81	class CXXDestructorDecl;
82	class Module;
83	class CoverageSourceInfo;
84	class InitSegAttr;
85
86	namespace CodeGen {
87
88	class CodeGenFunction;
89	class CodeGenTBAA;
90	class CGCXXABI;
91	class CGDebugInfo;
92	class CGObjCRuntime;
93	class CGOpenCLRuntime;
94	class CGOpenMPRuntime;
95	class CGCUDARuntime;
96	class CGHLSLRuntime;
97	class CoverageMappingModuleGen;
98	class TargetCodeGenInfo;
99
100	enum ForDefinition_t : bool {
101	NotForDefinition = false,
102	ForDefinition = true
103	};
104
105	/// The Counter with an optional additional Counter for
106	/// branches. `Skipped` counter can be calculated with `Executed` and
107	/// a common Counter (like `Parent`) as `(Parent-Executed)`.
108	///
109	/// In SingleByte mode, Counters are binary. Subtraction is not
110	/// applicable (but addition is capable). In this case, both
111	/// `Executed` and `Skipped` counters are required. `Skipped` is
112	/// `None` by default. It is allocated in the coverage mapping.
113	///
114	/// There might be cases that `Parent` could be induced with
115	/// `(Executed+Skipped)`. This is not always applicable.
116	class CounterPair {
117	public:
118	/// Optional value.
119	class ValueOpt {
120	private:
121	static constexpr uint32_t None = (1u << 31); /// None is allocated.
122	static constexpr uint32_t Mask = None - 1;
123
124	uint32_t Val;
125
126	public:
127	ValueOpt() : Val(None) {}
128
129	ValueOpt(unsigned InitVal) {
130	assert(!(InitVal & ~Mask));
131	Val = InitVal;
132	}
133
134	bool hasValue() const { return !(Val & None); }
135
136	operator uint32_t() const { return Val; }
137	};
138
139	ValueOpt Executed;
140	ValueOpt Skipped; /// May be None.
141
142	/// Initialized with Skipped=None.
143	CounterPair(unsigned Val) : Executed(Val) {}
144
145	// FIXME: Should work with {None, None}
146	CounterPair() : Executed(0) {}
147	};
148
149	struct OrderGlobalInitsOrStermFinalizers {
150	unsigned int priority;
151	unsigned int lex_order;
152	OrderGlobalInitsOrStermFinalizers(unsigned int p, unsigned int l)
153	: priority(p), lex_order(l) {}
154
155	bool operator==(const OrderGlobalInitsOrStermFinalizers &RHS) const {
156	return priority == RHS.priority && lex_order == RHS.lex_order;
157	}
158
159	bool operator<(const OrderGlobalInitsOrStermFinalizers &RHS) const {
160	return std::tie(args: priority, args: lex_order) <
161	std::tie(args: RHS.priority, args: RHS.lex_order);
162	}
163	};
164
165	struct ObjCEntrypoints {
166	ObjCEntrypoints() { memset(s: this, c: 0, n: sizeof(*this)); }
167
168	/// void objc_alloc(id);
169	llvm::FunctionCallee objc_alloc;
170
171	/// void objc_allocWithZone(id);
172	llvm::FunctionCallee objc_allocWithZone;
173
174	/// void objc_alloc_init(id);
175	llvm::FunctionCallee objc_alloc_init;
176
177	/// void objc_autoreleasePoolPop(void*);
178	llvm::FunctionCallee objc_autoreleasePoolPop;
179
180	/// void objc_autoreleasePoolPop(void*);
181	/// Note this method is used when we are using exception handling
182	llvm::FunctionCallee objc_autoreleasePoolPopInvoke;
183
184	/// void *objc_autoreleasePoolPush(void);
185	llvm::Function *objc_autoreleasePoolPush;
186
187	/// id objc_autorelease(id);
188	llvm::Function *objc_autorelease;
189
190	/// id objc_autorelease(id);
191	/// Note this is the runtime method not the intrinsic.
192	llvm::FunctionCallee objc_autoreleaseRuntimeFunction;
193
194	/// id objc_autoreleaseReturnValue(id);
195	llvm::Function *objc_autoreleaseReturnValue;
196
197	/// void objc_copyWeak(id *dest, id *src);
198	llvm::Function *objc_copyWeak;
199
200	/// void objc_destroyWeak(id*);
201	llvm::Function *objc_destroyWeak;
202
203	/// id objc_initWeak(id*, id);
204	llvm::Function *objc_initWeak;
205
206	/// id objc_loadWeak(id*);
207	llvm::Function *objc_loadWeak;
208
209	/// id objc_loadWeakRetained(id*);
210	llvm::Function *objc_loadWeakRetained;
211
212	/// void objc_moveWeak(id *dest, id *src);
213	llvm::Function *objc_moveWeak;
214
215	/// id objc_retain(id);
216	llvm::Function *objc_retain;
217
218	/// id objc_retain(id);
219	/// Note this is the runtime method not the intrinsic.
220	llvm::FunctionCallee objc_retainRuntimeFunction;
221
222	/// id objc_retainAutorelease(id);
223	llvm::Function *objc_retainAutorelease;
224
225	/// id objc_retainAutoreleaseReturnValue(id);
226	llvm::Function *objc_retainAutoreleaseReturnValue;
227
228	/// id objc_retainAutoreleasedReturnValue(id);
229	llvm::Function *objc_retainAutoreleasedReturnValue;
230
231	/// id objc_retainBlock(id);
232	llvm::Function *objc_retainBlock;
233
234	/// void objc_release(id);
235	llvm::Function *objc_release;
236
237	/// void objc_release(id);
238	/// Note this is the runtime method not the intrinsic.
239	llvm::FunctionCallee objc_releaseRuntimeFunction;
240
241	/// void objc_storeStrong(id*, id);
242	llvm::Function *objc_storeStrong;
243
244	/// id objc_storeWeak(id*, id);
245	llvm::Function *objc_storeWeak;
246
247	/// id objc_unsafeClaimAutoreleasedReturnValue(id);
248	llvm::Function *objc_unsafeClaimAutoreleasedReturnValue;
249
250	/// A void(void) inline asm to use to mark that the return value of
251	/// a call will be immediately retain.
252	llvm::InlineAsm *retainAutoreleasedReturnValueMarker;
253
254	/// void clang.arc.use(...);
255	llvm::Function *clang_arc_use;
256
257	/// void clang.arc.noop.use(...);
258	llvm::Function *clang_arc_noop_use;
259	};
260
261	/// This class records statistics on instrumentation based profiling.
262	class InstrProfStats {
263	uint32_t VisitedInMainFile = 0;
264	uint32_t MissingInMainFile = 0;
265	uint32_t Visited = 0;
266	uint32_t Missing = 0;
267	uint32_t Mismatched = 0;
268
269	public:
270	InstrProfStats() = default;
271	/// Record that we've visited a function and whether or not that function was
272	/// in the main source file.
273	void addVisited(bool MainFile) {
274	if (MainFile)
275	++VisitedInMainFile;
276	++Visited;
277	}
278	/// Record that a function we've visited has no profile data.
279	void addMissing(bool MainFile) {
280	if (MainFile)
281	++MissingInMainFile;
282	++Missing;
283	}
284	/// Record that a function we've visited has mismatched profile data.
285	void addMismatched(bool MainFile) { ++Mismatched; }
286	/// Whether or not the stats we've gathered indicate any potential problems.
287	bool hasDiagnostics() { return Missing || Mismatched; }
288	/// Report potential problems we've found to \c Diags.
289	void reportDiagnostics(DiagnosticsEngine &Diags, StringRef MainFile);
290	};
291
292	/// A pair of helper functions for a __block variable.
293	class BlockByrefHelpers : public llvm::FoldingSetNode {
294	// MSVC requires this type to be complete in order to process this
295	// header.
296	public:
297	llvm::Constant *CopyHelper;
298	llvm::Constant *DisposeHelper;
299
300	/// The alignment of the field. This is important because
301	/// different offsets to the field within the byref struct need to
302	/// have different helper functions.
303	CharUnits Alignment;
304
305	BlockByrefHelpers(CharUnits alignment)
306	: CopyHelper(nullptr), DisposeHelper(nullptr), Alignment(alignment) {}
307	BlockByrefHelpers(const BlockByrefHelpers &) = default;
308	virtual ~BlockByrefHelpers();
309
310	void Profile(llvm::FoldingSetNodeID &id) const {
311	id.AddInteger(I: Alignment.getQuantity());
312	profileImpl(id);
313	}
314	virtual void profileImpl(llvm::FoldingSetNodeID &id) const = 0;
315
316	virtual bool needsCopy() const { return true; }
317	virtual void emitCopy(CodeGenFunction &CGF, Address dest, Address src) = 0;
318
319	virtual bool needsDispose() const { return true; }
320	virtual void emitDispose(CodeGenFunction &CGF, Address field) = 0;
321	};
322
323	/// This class organizes the cross-function state that is used while generating
324	/// LLVM code.
325	class CodeGenModule : public CodeGenTypeCache {
326	CodeGenModule(const CodeGenModule &) = delete;
327	void operator=(const CodeGenModule &) = delete;
328
329	public:
330	struct Structor {
331	Structor()
332	: Priority(0), LexOrder(~0u), Initializer(nullptr),
333	AssociatedData(nullptr) {}
334	Structor(int Priority, unsigned LexOrder, llvm::Constant *Initializer,
335	llvm::Constant *AssociatedData)
336	: Priority(Priority), LexOrder(LexOrder), Initializer(Initializer),
337	AssociatedData(AssociatedData) {}
338	int Priority;
339	unsigned LexOrder;
340	llvm::Constant *Initializer;
341	llvm::Constant *AssociatedData;
342	};
343
344	typedef std::vector<Structor> CtorList;
345
346	private:
347	ASTContext &Context;
348	const LangOptions &LangOpts;
349	IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS; // Only used for debug info.
350	const HeaderSearchOptions &HeaderSearchOpts; // Only used for debug info.
351	const PreprocessorOptions &PreprocessorOpts; // Only used for debug info.
352	const CodeGenOptions &CodeGenOpts;
353	unsigned NumAutoVarInit = 0;
354	llvm::Module &TheModule;
355	DiagnosticsEngine &Diags;
356	const TargetInfo &Target;
357	std::unique_ptr<CGCXXABI> ABI;
358	llvm::LLVMContext &VMContext;
359	std::string ModuleNameHash;
360	bool CXX20ModuleInits = false;
361	std::unique_ptr<CodeGenTBAA> TBAA;
362
363	mutable std::unique_ptr<TargetCodeGenInfo> TheTargetCodeGenInfo;
364
365	// This should not be moved earlier, since its initialization depends on some
366	// of the previous reference members being already initialized and also checks
367	// if TheTargetCodeGenInfo is NULL
368	std::unique_ptr<CodeGenTypes> Types;
369
370	/// Holds information about C++ vtables.
371	CodeGenVTables VTables;
372
373	std::unique_ptr<CGObjCRuntime> ObjCRuntime;
374	std::unique_ptr<CGOpenCLRuntime> OpenCLRuntime;
375	std::unique_ptr<CGOpenMPRuntime> OpenMPRuntime;
376	std::unique_ptr<CGCUDARuntime> CUDARuntime;
377	std::unique_ptr<CGHLSLRuntime> HLSLRuntime;
378	std::unique_ptr<CGDebugInfo> DebugInfo;
379	std::unique_ptr<ObjCEntrypoints> ObjCData;
380	llvm::MDNode *NoObjCARCExceptionsMetadata = nullptr;
381	std::unique_ptr<llvm::IndexedInstrProfReader> PGOReader;
382	InstrProfStats PGOStats;
383	std::unique_ptr<llvm::SanitizerStatReport> SanStats;
384	StackExhaustionHandler StackHandler;
385
386	// A set of references that have only been seen via a weakref so far. This is
387	// used to remove the weak of the reference if we ever see a direct reference
388	// or a definition.
389	llvm::SmallPtrSet<llvm::GlobalValue*, 10> WeakRefReferences;
390
391	/// This contains all the decls which have definitions but/ which are deferred
392	/// for emission and therefore should only be output if they are actually
393	/// used. If a decl is in this, then it is known to have not been referenced
394	/// yet.
395	llvm::DenseMap<StringRef, GlobalDecl> DeferredDecls;
396
397	llvm::StringSet<llvm::BumpPtrAllocator> DeferredResolversToEmit;
398
399	/// This is a list of deferred decls which we have seen that *are* actually
400	/// referenced. These get code generated when the module is done.
401	std::vector<GlobalDecl> DeferredDeclsToEmit;
402	void addDeferredDeclToEmit(GlobalDecl GD) {
403	DeferredDeclsToEmit.emplace_back(args&: GD);
404	addEmittedDeferredDecl(GD);
405	}
406
407	/// Decls that were DeferredDecls and have now been emitted.
408	llvm::DenseMap<llvm::StringRef, GlobalDecl> EmittedDeferredDecls;
409
410	void addEmittedDeferredDecl(GlobalDecl GD) {
411	// Reemission is only needed in incremental mode.
412	if (!Context.getLangOpts().IncrementalExtensions)
413	return;
414
415	// Assume a linkage by default that does not need reemission.
416	auto L = llvm::GlobalValue::ExternalLinkage;
417	if (llvm::isa<FunctionDecl>(Val: GD.getDecl()))
418	L = getFunctionLinkage(GD);
419	else if (auto *VD = llvm::dyn_cast<VarDecl>(Val: GD.getDecl()))
420	L = getLLVMLinkageVarDefinition(VD);
421
422	if (llvm::GlobalValue::isInternalLinkage(Linkage: L) ||
423	llvm::GlobalValue::isLinkOnceLinkage(Linkage: L) ||
424	llvm::GlobalValue::isWeakLinkage(Linkage: L)) {
425	EmittedDeferredDecls[getMangledName(GD)] = GD;
426	}
427	}
428
429	/// List of alias we have emitted. Used to make sure that what they point to
430	/// is defined once we get to the end of the of the translation unit.
431	std::vector<GlobalDecl> Aliases;
432
433	/// List of multiversion functions to be emitted. This list is processed in
434	/// conjunction with other deferred symbols and is used to ensure that
435	/// multiversion function resolvers and ifuncs are defined and emitted.
436	std::vector<GlobalDecl> MultiVersionFuncs;
437
438	llvm::MapVector<StringRef, llvm::TrackingVH<llvm::Constant>> Replacements;
439
440	/// List of global values to be replaced with something else. Used when we
441	/// want to replace a GlobalValue but can't identify it by its mangled name
442	/// anymore (because the name is already taken).
443	llvm::SmallVector<std::pair<llvm::GlobalValue *, llvm::Constant *>, 8>
444	GlobalValReplacements;
445
446	/// Variables for which we've emitted globals containing their constant
447	/// values along with the corresponding globals, for opportunistic reuse.
448	llvm::DenseMap<const VarDecl*, llvm::GlobalVariable*> InitializerConstants;
449
450	/// Set of global decls for which we already diagnosed mangled name conflict.
451	/// Required to not issue a warning (on a mangling conflict) multiple times
452	/// for the same decl.
453	llvm::DenseSet<GlobalDecl> DiagnosedConflictingDefinitions;
454
455	/// A queue of (optional) vtables to consider emitting.
456	std::vector<const CXXRecordDecl*> DeferredVTables;
457
458	/// A queue of (optional) vtables that may be emitted opportunistically.
459	std::vector<const CXXRecordDecl *> OpportunisticVTables;
460
461	/// List of global values which are required to be present in the object file;
462	/// bitcast to i8*. This is used for forcing visibility of symbols which may
463	/// otherwise be optimized out.
464	std::vector<llvm::WeakTrackingVH> LLVMUsed;
465	std::vector<llvm::WeakTrackingVH> LLVMCompilerUsed;
466
467	/// Store the list of global constructors and their respective priorities to
468	/// be emitted when the translation unit is complete.
469	CtorList GlobalCtors;
470
471	/// Store the list of global destructors and their respective priorities to be
472	/// emitted when the translation unit is complete.
473	CtorList GlobalDtors;
474
475	/// An ordered map of canonical GlobalDecls to their mangled names.
476	llvm::MapVector<GlobalDecl, StringRef> MangledDeclNames;
477	llvm::StringMap<GlobalDecl, llvm::BumpPtrAllocator> Manglings;
478
479	/// Global annotations.
480	std::vector<llvm::Constant*> Annotations;
481
482	// Store deferred function annotations so they can be emitted at the end with
483	// most up to date ValueDecl that will have all the inherited annotations.
484	llvm::MapVector<StringRef, const ValueDecl *> DeferredAnnotations;
485
486	/// Map used to get unique annotation strings.
487	llvm::StringMap<llvm::Constant*> AnnotationStrings;
488
489	/// Used for uniquing of annotation arguments.
490	llvm::DenseMap<unsigned, llvm::Constant *> AnnotationArgs;
491
492	llvm::StringMap<llvm::GlobalVariable *> CFConstantStringMap;
493
494	llvm::DenseMap<llvm::Constant *, llvm::GlobalVariable *> ConstantStringMap;
495	llvm::DenseMap<const UnnamedGlobalConstantDecl *, llvm::GlobalVariable *>
496	UnnamedGlobalConstantDeclMap;
497	llvm::DenseMap<const Decl*, llvm::Constant *> StaticLocalDeclMap;
498	llvm::DenseMap<const Decl*, llvm::GlobalVariable*> StaticLocalDeclGuardMap;
499	llvm::DenseMap<const Expr*, llvm::Constant *> MaterializedGlobalTemporaryMap;
500
501	llvm::DenseMap<QualType, llvm::Constant *> AtomicSetterHelperFnMap;
502	llvm::DenseMap<QualType, llvm::Constant *> AtomicGetterHelperFnMap;
503
504	/// Map used to get unique type descriptor constants for sanitizers.
505	llvm::DenseMap<QualType, llvm::Constant *> TypeDescriptorMap;
506
507	/// Map used to track internal linkage functions declared within
508	/// extern "C" regions.
509	typedef llvm::MapVector<IdentifierInfo *,
510	llvm::GlobalValue *> StaticExternCMap;
511	StaticExternCMap StaticExternCValues;
512
513	/// thread_local variables defined or used in this TU.
514	std::vector<const VarDecl *> CXXThreadLocals;
515
516	/// thread_local variables with initializers that need to run
517	/// before any thread_local variable in this TU is odr-used.
518	std::vector<llvm::Function *> CXXThreadLocalInits;
519	std::vector<const VarDecl *> CXXThreadLocalInitVars;
520
521	/// Global variables with initializers that need to run before main.
522	std::vector<llvm::Function *> CXXGlobalInits;
523
524	/// When a C++ decl with an initializer is deferred, null is
525	/// appended to CXXGlobalInits, and the index of that null is placed
526	/// here so that the initializer will be performed in the correct
527	/// order. Once the decl is emitted, the index is replaced with ~0U to ensure
528	/// that we don't re-emit the initializer.
529	llvm::DenseMap<const Decl*, unsigned> DelayedCXXInitPosition;
530
531	typedef std::pair<OrderGlobalInitsOrStermFinalizers, llvm::Function *>
532	GlobalInitData;
533
534	// When a tail call is performed on an "undefined" symbol, on PPC without pc
535	// relative feature, the tail call is not allowed. In "EmitCall" for such
536	// tail calls, the "undefined" symbols may be forward declarations, their
537	// definitions are provided in the module after the callsites. For such tail
538	// calls, diagnose message should not be emitted.
539	llvm::SmallSetVector<std::pair<const FunctionDecl *, SourceLocation>, 4>
540	MustTailCallUndefinedGlobals;
541
542	struct GlobalInitPriorityCmp {
543	bool operator()(const GlobalInitData &LHS,
544	const GlobalInitData &RHS) const {
545	return LHS.first.priority < RHS.first.priority;
546	}
547	};
548
549	/// Global variables with initializers whose order of initialization is set by
550	/// init_priority attribute.
551	SmallVector<GlobalInitData, 8> PrioritizedCXXGlobalInits;
552
553	/// Global destructor functions and arguments that need to run on termination.
554	/// When UseSinitAndSterm is set, it instead contains sterm finalizer
555	/// functions, which also run on unloading a shared library.
556	typedef std::tuple<llvm::FunctionType *, llvm::WeakTrackingVH,
557	llvm::Constant *>
558	CXXGlobalDtorsOrStermFinalizer_t;
559	SmallVector<CXXGlobalDtorsOrStermFinalizer_t, 8>
560	CXXGlobalDtorsOrStermFinalizers;
561
562	typedef std::pair<OrderGlobalInitsOrStermFinalizers, llvm::Function *>
563	StermFinalizerData;
564
565	struct StermFinalizerPriorityCmp {
566	bool operator()(const StermFinalizerData &LHS,
567	const StermFinalizerData &RHS) const {
568	return LHS.first.priority < RHS.first.priority;
569	}
570	};
571
572	/// Global variables with sterm finalizers whose order of initialization is
573	/// set by init_priority attribute.
574	SmallVector<StermFinalizerData, 8> PrioritizedCXXStermFinalizers;
575
576	/// The complete set of modules that has been imported.
577	llvm::SetVector<clang::Module *> ImportedModules;
578
579	/// The set of modules for which the module initializers
580	/// have been emitted.
581	llvm::SmallPtrSet<clang::Module *, 16> EmittedModuleInitializers;
582
583	/// A vector of metadata strings for linker options.
584	SmallVector<llvm::MDNode *, 16> LinkerOptionsMetadata;
585
586	/// A vector of metadata strings for dependent libraries for ELF.
587	SmallVector<llvm::MDNode *, 16> ELFDependentLibraries;
588
589	/// @name Cache for Objective-C runtime types
590	/// @{
591
592	/// Cached reference to the class for constant strings. This value has type
593	/// int * but is actually an Obj-C class pointer.
594	llvm::WeakTrackingVH CFConstantStringClassRef;
595
596	/// The type used to describe the state of a fast enumeration in
597	/// Objective-C's for..in loop.
598	QualType ObjCFastEnumerationStateType;
599
600	/// @}
601
602	/// Lazily create the Objective-C runtime
603	void createObjCRuntime();
604
605	void createOpenCLRuntime();
606	void createOpenMPRuntime();
607	void createCUDARuntime();
608	void createHLSLRuntime();
609
610	bool isTriviallyRecursive(const FunctionDecl *F);
611	bool shouldEmitFunction(GlobalDecl GD);
612	// Whether a global variable should be emitted by CUDA/HIP host/device
613	// related attributes.
614	bool shouldEmitCUDAGlobalVar(const VarDecl *VD) const;
615	bool shouldOpportunisticallyEmitVTables();
616	/// Map used to be sure we don't emit the same CompoundLiteral twice.
617	llvm::DenseMap<const CompoundLiteralExpr *, llvm::GlobalVariable *>
618	EmittedCompoundLiterals;
619
620	/// Map of the global blocks we've emitted, so that we don't have to re-emit
621	/// them if the constexpr evaluator gets aggressive.
622	llvm::DenseMap<const BlockExpr *, llvm::Constant *> EmittedGlobalBlocks;
623
624	/// @name Cache for Blocks Runtime Globals
625	/// @{
626
627	llvm::Constant *NSConcreteGlobalBlock = nullptr;
628	llvm::Constant *NSConcreteStackBlock = nullptr;
629
630	llvm::FunctionCallee BlockObjectAssign = nullptr;
631	llvm::FunctionCallee BlockObjectDispose = nullptr;
632
633	llvm::Type *BlockDescriptorType = nullptr;
634	llvm::Type *GenericBlockLiteralType = nullptr;
635
636	struct {
637	int GlobalUniqueCount;
638	} Block;
639
640	GlobalDecl initializedGlobalDecl;
641
642	/// @}
643
644	/// void @llvm.lifetime.start(i64 %size, i8* nocapture <ptr>)
645	llvm::Function *LifetimeStartFn = nullptr;
646
647	/// void @llvm.lifetime.end(i64 %size, i8* nocapture <ptr>)
648	llvm::Function *LifetimeEndFn = nullptr;
649
650	/// void @llvm.fake.use(...)
651	llvm::Function *FakeUseFn = nullptr;
652
653	std::unique_ptr<SanitizerMetadata> SanitizerMD;
654
655	llvm::MapVector<const Decl *, bool> DeferredEmptyCoverageMappingDecls;
656
657	std::unique_ptr<CoverageMappingModuleGen> CoverageMapping;
658
659	/// Mapping from canonical types to their metadata identifiers. We need to
660	/// maintain this mapping because identifiers may be formed from distinct
661	/// MDNodes.
662	typedef llvm::DenseMap<QualType, llvm::Metadata *> MetadataTypeMap;
663	MetadataTypeMap MetadataIdMap;
664	MetadataTypeMap VirtualMetadataIdMap;
665	MetadataTypeMap GeneralizedMetadataIdMap;
666
667	// Helps squashing blocks of TopLevelStmtDecl into a single llvm::Function
668	// when used with -fincremental-extensions.
669	std::pair<std::unique_ptr<CodeGenFunction>, const TopLevelStmtDecl *>
670	GlobalTopLevelStmtBlockInFlight;
671
672	llvm::DenseMap<GlobalDecl, uint16_t> PtrAuthDiscriminatorHashes;
673
674	llvm::DenseMap<const CXXRecordDecl *, std::optional<PointerAuthQualifier>>
675	VTablePtrAuthInfos;
676	std::optional<PointerAuthQualifier>
677	computeVTPointerAuthentication(const CXXRecordDecl *ThisClass);
678
679	AtomicOptions AtomicOpts;
680
681	public:
682	CodeGenModule(ASTContext &C, IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS,
683	const HeaderSearchOptions &headersearchopts,
684	const PreprocessorOptions &ppopts,
685	const CodeGenOptions &CodeGenOpts, llvm::Module &M,
686	DiagnosticsEngine &Diags,
687	CoverageSourceInfo *CoverageInfo = nullptr);
688
689	~CodeGenModule();
690
691	void clear();
692
693	/// Finalize LLVM code generation.
694	void Release();
695
696	/// Get the current Atomic options.
697	AtomicOptions getAtomicOpts() { return AtomicOpts; }
698
699	/// Set the current Atomic options.
700	void setAtomicOpts(AtomicOptions AO) { AtomicOpts = AO; }
701
702	/// Return true if we should emit location information for expressions.
703	bool getExpressionLocationsEnabled() const;
704
705	/// Return a reference to the configured Objective-C runtime.
706	CGObjCRuntime &getObjCRuntime() {
707	if (!ObjCRuntime) createObjCRuntime();
708	return *ObjCRuntime;
709	}
710
711	/// Return true iff an Objective-C runtime has been configured.
712	bool hasObjCRuntime() { return !!ObjCRuntime; }
713
714	const std::string &getModuleNameHash() const { return ModuleNameHash; }
715
716	/// Return a reference to the configured OpenCL runtime.
717	CGOpenCLRuntime &getOpenCLRuntime() {
718	assert(OpenCLRuntime != nullptr);
719	return *OpenCLRuntime;
720	}
721
722	/// Return a reference to the configured OpenMP runtime.
723	CGOpenMPRuntime &getOpenMPRuntime() {
724	assert(OpenMPRuntime != nullptr);
725	return *OpenMPRuntime;
726	}
727
728	/// Return a reference to the configured CUDA runtime.
729	CGCUDARuntime &getCUDARuntime() {
730	assert(CUDARuntime != nullptr);
731	return *CUDARuntime;
732	}
733
734	/// Return a reference to the configured HLSL runtime.
735	CGHLSLRuntime &getHLSLRuntime() {
736	assert(HLSLRuntime != nullptr);
737	return *HLSLRuntime;
738	}
739
740	ObjCEntrypoints &getObjCEntrypoints() const {
741	assert(ObjCData != nullptr);
742	return *ObjCData;
743	}
744
745	// Version checking functions, used to implement ObjC's @available:
746	// i32 @__isOSVersionAtLeast(i32, i32, i32)
747	llvm::FunctionCallee IsOSVersionAtLeastFn = nullptr;
748	// i32 @__isPlatformVersionAtLeast(i32, i32, i32, i32)
749	llvm::FunctionCallee IsPlatformVersionAtLeastFn = nullptr;
750
751	InstrProfStats &getPGOStats() { return PGOStats; }
752	llvm::IndexedInstrProfReader *getPGOReader() const { return PGOReader.get(); }
753
754	CoverageMappingModuleGen *getCoverageMapping() const {
755	return CoverageMapping.get();
756	}
757
758	llvm::Constant *getStaticLocalDeclAddress(const VarDecl *D) {
759	return StaticLocalDeclMap[D];
760	}
761	void setStaticLocalDeclAddress(const VarDecl *D,
762	llvm::Constant *C) {
763	StaticLocalDeclMap[D] = C;
764	}
765
766	llvm::Constant *
767	getOrCreateStaticVarDecl(const VarDecl &D,
768	llvm::GlobalValue::LinkageTypes Linkage);
769
770	llvm::GlobalVariable *getStaticLocalDeclGuardAddress(const VarDecl *D) {
771	return StaticLocalDeclGuardMap[D];
772	}
773	void setStaticLocalDeclGuardAddress(const VarDecl *D,
774	llvm::GlobalVariable *C) {
775	StaticLocalDeclGuardMap[D] = C;
776	}
777
778	Address createUnnamedGlobalFrom(const VarDecl &D, llvm::Constant *Constant,
779	CharUnits Align);
780
781	bool lookupRepresentativeDecl(StringRef MangledName,
782	GlobalDecl &Result) const;
783
784	llvm::Constant *getAtomicSetterHelperFnMap(QualType Ty) {
785	return AtomicSetterHelperFnMap[Ty];
786	}
787	void setAtomicSetterHelperFnMap(QualType Ty,
788	llvm::Constant *Fn) {
789	AtomicSetterHelperFnMap[Ty] = Fn;
790	}
791
792	llvm::Constant *getAtomicGetterHelperFnMap(QualType Ty) {
793	return AtomicGetterHelperFnMap[Ty];
794	}
795	void setAtomicGetterHelperFnMap(QualType Ty,
796	llvm::Constant *Fn) {
797	AtomicGetterHelperFnMap[Ty] = Fn;
798	}
799
800	llvm::Constant *getTypeDescriptorFromMap(QualType Ty) {
801	return TypeDescriptorMap[Ty];
802	}
803	void setTypeDescriptorInMap(QualType Ty, llvm::Constant *C) {
804	TypeDescriptorMap[Ty] = C;
805	}
806
807	CGDebugInfo *getModuleDebugInfo() { return DebugInfo.get(); }
808
809	llvm::MDNode *getNoObjCARCExceptionsMetadata() {
810	if (!NoObjCARCExceptionsMetadata)
811	NoObjCARCExceptionsMetadata = llvm::MDNode::get(Context&: getLLVMContext(), MDs: {});
812	return NoObjCARCExceptionsMetadata;
813	}
814
815	ASTContext &getContext() const { return Context; }
816	const LangOptions &getLangOpts() const { return LangOpts; }
817	const IntrusiveRefCntPtr<llvm::vfs::FileSystem> &getFileSystem() const {
818	return FS;
819	}
820	const HeaderSearchOptions &getHeaderSearchOpts()
821	const { return HeaderSearchOpts; }
822	const PreprocessorOptions &getPreprocessorOpts()
823	const { return PreprocessorOpts; }
824	const CodeGenOptions &getCodeGenOpts() const { return CodeGenOpts; }
825	llvm::Module &getModule() const { return TheModule; }
826	DiagnosticsEngine &getDiags() const { return Diags; }
827	const llvm::DataLayout &getDataLayout() const {
828	return TheModule.getDataLayout();
829	}
830	const TargetInfo &getTarget() const { return Target; }
831	const llvm::Triple &getTriple() const { return Target.getTriple(); }
832	bool supportsCOMDAT() const;
833	void maybeSetTrivialComdat(const Decl &D, llvm::GlobalObject &GO);
834
835	const ABIInfo &getABIInfo();
836	CGCXXABI &getCXXABI() const { return *ABI; }
837	llvm::LLVMContext &getLLVMContext() { return VMContext; }
838
839	bool shouldUseTBAA() const { return TBAA != nullptr; }
840
841	const TargetCodeGenInfo &getTargetCodeGenInfo();
842
843	CodeGenTypes &getTypes() { return *Types; }
844
845	CodeGenVTables &getVTables() { return VTables; }
846
847	ItaniumVTableContext &getItaniumVTableContext() {
848	return VTables.getItaniumVTableContext();
849	}
850
851	const ItaniumVTableContext &getItaniumVTableContext() const {
852	return VTables.getItaniumVTableContext();
853	}
854
855	MicrosoftVTableContext &getMicrosoftVTableContext() {
856	return VTables.getMicrosoftVTableContext();
857	}
858
859	CtorList &getGlobalCtors() { return GlobalCtors; }
860	CtorList &getGlobalDtors() { return GlobalDtors; }
861
862	/// getTBAATypeInfo - Get metadata used to describe accesses to objects of
863	/// the given type.
864	llvm::MDNode *getTBAATypeInfo(QualType QTy);
865
866	/// getTBAAAccessInfo - Get TBAA information that describes an access to
867	/// an object of the given type.
868	TBAAAccessInfo getTBAAAccessInfo(QualType AccessType);
869
870	/// getTBAAVTablePtrAccessInfo - Get the TBAA information that describes an
871	/// access to a virtual table pointer.
872	TBAAAccessInfo getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType);
873
874	llvm::MDNode *getTBAAStructInfo(QualType QTy);
875
876	/// getTBAABaseTypeInfo - Get metadata that describes the given base access
877	/// type. Return null if the type is not suitable for use in TBAA access tags.
878	llvm::MDNode *getTBAABaseTypeInfo(QualType QTy);
879
880	/// getTBAAAccessTagInfo - Get TBAA tag for a given memory access.
881	llvm::MDNode *getTBAAAccessTagInfo(TBAAAccessInfo Info);
882
883	/// mergeTBAAInfoForCast - Get merged TBAA information for the purposes of
884	/// type casts.
885	TBAAAccessInfo mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
886	TBAAAccessInfo TargetInfo);
887
888	/// mergeTBAAInfoForConditionalOperator - Get merged TBAA information for the
889	/// purposes of conditional operator.
890	TBAAAccessInfo mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
891	TBAAAccessInfo InfoB);
892
893	/// mergeTBAAInfoForMemoryTransfer - Get merged TBAA information for the
894	/// purposes of memory transfer calls.
895	TBAAAccessInfo mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
896	TBAAAccessInfo SrcInfo);
897
898	/// getTBAAInfoForSubobject - Get TBAA information for an access with a given
899	/// base lvalue.
900	TBAAAccessInfo getTBAAInfoForSubobject(LValue Base, QualType AccessType) {
901	if (Base.getTBAAInfo().isMayAlias())
902	return TBAAAccessInfo::getMayAliasInfo();
903	return getTBAAAccessInfo(AccessType);
904	}
905
906	bool isPaddedAtomicType(QualType type);
907	bool isPaddedAtomicType(const AtomicType *type);
908
909	/// DecorateInstructionWithTBAA - Decorate the instruction with a TBAA tag.
910	void DecorateInstructionWithTBAA(llvm::Instruction *Inst,
911	TBAAAccessInfo TBAAInfo);
912
913	/// Adds !invariant.barrier !tag to instruction
914	void DecorateInstructionWithInvariantGroup(llvm::Instruction *I,
915	const CXXRecordDecl *RD);
916
917	/// Emit the given number of characters as a value of type size_t.
918	llvm::ConstantInt *getSize(CharUnits numChars);
919
920	/// Set the visibility for the given LLVM GlobalValue.
921	void setGlobalVisibility(llvm::GlobalValue *GV, const NamedDecl *D) const;
922
923	void setDSOLocal(llvm::GlobalValue *GV) const;
924
925	bool shouldMapVisibilityToDLLExport(const NamedDecl *D) const {
926	return getLangOpts().hasDefaultVisibilityExportMapping() && D &&
927	(D->getLinkageAndVisibility().getVisibility() ==
928	DefaultVisibility) &&
929	(getLangOpts().isAllDefaultVisibilityExportMapping() ||
930	(getLangOpts().isExplicitDefaultVisibilityExportMapping() &&
931	D->getLinkageAndVisibility().isVisibilityExplicit()));
932	}
933	void setDLLImportDLLExport(llvm::GlobalValue *GV, GlobalDecl D) const;
934	void setDLLImportDLLExport(llvm::GlobalValue *GV, const NamedDecl *D) const;
935	/// Set visibility, dllimport/dllexport and dso_local.
936	/// This must be called after dllimport/dllexport is set.
937	void setGVProperties(llvm::GlobalValue *GV, GlobalDecl GD) const;
938	void setGVProperties(llvm::GlobalValue *GV, const NamedDecl *D) const;
939
940	void setGVPropertiesAux(llvm::GlobalValue *GV, const NamedDecl *D) const;
941
942	/// Set the TLS mode for the given LLVM GlobalValue for the thread-local
943	/// variable declaration D.
944	void setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const;
945
946	/// Get LLVM TLS mode from CodeGenOptions.
947	llvm::GlobalVariable::ThreadLocalMode GetDefaultLLVMTLSModel() const;
948
949	static llvm::GlobalValue::VisibilityTypes GetLLVMVisibility(Visibility V) {
950	switch (V) {
951	case DefaultVisibility: return llvm::GlobalValue::DefaultVisibility;
952	case HiddenVisibility: return llvm::GlobalValue::HiddenVisibility;
953	case ProtectedVisibility: return llvm::GlobalValue::ProtectedVisibility;
954	}
955	llvm_unreachable("unknown visibility!");
956	}
957
958	llvm::Constant *GetAddrOfGlobal(GlobalDecl GD,
959	ForDefinition_t IsForDefinition
960	= NotForDefinition);
961
962	/// Will return a global variable of the given type. If a variable with a
963	/// different type already exists then a new variable with the right type
964	/// will be created and all uses of the old variable will be replaced with a
965	/// bitcast to the new variable.
966	llvm::GlobalVariable *
967	CreateOrReplaceCXXRuntimeVariable(StringRef Name, llvm::Type *Ty,
968	llvm::GlobalValue::LinkageTypes Linkage,
969	llvm::Align Alignment);
970
971	llvm::Function *CreateGlobalInitOrCleanUpFunction(
972	llvm::FunctionType *ty, const Twine &name, const CGFunctionInfo &FI,
973	SourceLocation Loc = SourceLocation(), bool TLS = false,
974	llvm::GlobalVariable::LinkageTypes Linkage =
975	llvm::GlobalVariable::InternalLinkage);
976
977	/// Return the AST address space of the underlying global variable for D, as
978	/// determined by its declaration. Normally this is the same as the address
979	/// space of D's type, but in CUDA, address spaces are associated with
980	/// declarations, not types. If D is nullptr, return the default address
981	/// space for global variable.
982	///
983	/// For languages without explicit address spaces, if D has default address
984	/// space, target-specific global or constant address space may be returned.
985	LangAS GetGlobalVarAddressSpace(const VarDecl *D);
986
987	/// Return the AST address space of constant literal, which is used to emit
988	/// the constant literal as global variable in LLVM IR.
989	/// Note: This is not necessarily the address space of the constant literal
990	/// in AST. For address space agnostic language, e.g. C++, constant literal
991	/// in AST is always in default address space.
992	LangAS GetGlobalConstantAddressSpace() const;
993
994	/// Return the llvm::Constant for the address of the given global variable.
995	/// If Ty is non-null and if the global doesn't exist, then it will be created
996	/// with the specified type instead of whatever the normal requested type
997	/// would be. If IsForDefinition is true, it is guaranteed that an actual
998	/// global with type Ty will be returned, not conversion of a variable with
999	/// the same mangled name but some other type.
1000	llvm::Constant *GetAddrOfGlobalVar(const VarDecl *D,
1001	llvm::Type *Ty = nullptr,
1002	ForDefinition_t IsForDefinition
1003	= NotForDefinition);
1004
1005	/// Return the address of the given function. If Ty is non-null, then this
1006	/// function will use the specified type if it has to create it.
1007	llvm::Constant *GetAddrOfFunction(GlobalDecl GD, llvm::Type *Ty = nullptr,
1008	bool ForVTable = false,
1009	bool DontDefer = false,
1010	ForDefinition_t IsForDefinition
1011	= NotForDefinition);
1012
1013	// Return the function body address of the given function.
1014	llvm::Constant *GetFunctionStart(const ValueDecl *Decl);
1015
1016	/// Return a function pointer for a reference to the given function.
1017	/// This correctly handles weak references, but does not apply a
1018	/// pointer signature.
1019	llvm::Constant *getRawFunctionPointer(GlobalDecl GD,
1020	llvm::Type *Ty = nullptr);
1021
1022	/// Return the ABI-correct function pointer value for a reference
1023	/// to the given function. This will apply a pointer signature if
1024	/// necessary, caching the result for the given function.
1025	llvm::Constant *getFunctionPointer(GlobalDecl GD, llvm::Type *Ty = nullptr);
1026
1027	/// Return the ABI-correct function pointer value for a reference
1028	/// to the given function. This will apply a pointer signature if
1029	/// necessary.
1030	llvm::Constant *getFunctionPointer(llvm::Constant *Pointer,
1031	QualType FunctionType);
1032
1033	llvm::Constant *getMemberFunctionPointer(const FunctionDecl *FD,
1034	llvm::Type *Ty = nullptr);
1035
1036	llvm::Constant *getMemberFunctionPointer(llvm::Constant *Pointer,
1037	QualType FT);
1038
1039	CGPointerAuthInfo getFunctionPointerAuthInfo(QualType T);
1040
1041	CGPointerAuthInfo getMemberFunctionPointerAuthInfo(QualType FT);
1042
1043	CGPointerAuthInfo getPointerAuthInfoForPointeeType(QualType type);
1044
1045	CGPointerAuthInfo getPointerAuthInfoForType(QualType type);
1046
1047	bool shouldSignPointer(const PointerAuthSchema &Schema);
1048	llvm::Constant *getConstantSignedPointer(llvm::Constant *Pointer,
1049	const PointerAuthSchema &Schema,
1050	llvm::Constant *StorageAddress,
1051	GlobalDecl SchemaDecl,
1052	QualType SchemaType);
1053
1054	llvm::Constant *
1055	getConstantSignedPointer(llvm::Constant *Pointer, unsigned Key,
1056	llvm::Constant *StorageAddress,
1057	llvm::ConstantInt *OtherDiscriminator);
1058
1059	llvm::ConstantInt *
1060	getPointerAuthOtherDiscriminator(const PointerAuthSchema &Schema,
1061	GlobalDecl SchemaDecl, QualType SchemaType);
1062
1063	uint16_t getPointerAuthDeclDiscriminator(GlobalDecl GD);
1064	std::optional<CGPointerAuthInfo>
1065	getVTablePointerAuthInfo(CodeGenFunction *Context,
1066	const CXXRecordDecl *Record,
1067	llvm::Value *StorageAddress);
1068
1069	std::optional<PointerAuthQualifier>
1070	getVTablePointerAuthentication(const CXXRecordDecl *thisClass);
1071
1072	CGPointerAuthInfo EmitPointerAuthInfo(const RecordDecl *RD);
1073
1074	// Return whether RTTI information should be emitted for this target.
1075	bool shouldEmitRTTI(bool ForEH = false) {
1076	return (ForEH || getLangOpts().RTTI) &&
1077	(!getLangOpts().isTargetDevice() || !getTriple().isGPU());
1078	}
1079
1080	/// Get the address of the RTTI descriptor for the given type.
1081	llvm::Constant *GetAddrOfRTTIDescriptor(QualType Ty, bool ForEH = false);
1082
1083	/// Get the address of a GUID.
1084	ConstantAddress GetAddrOfMSGuidDecl(const MSGuidDecl *GD);
1085
1086	/// Get the address of a UnnamedGlobalConstant
1087	ConstantAddress
1088	GetAddrOfUnnamedGlobalConstantDecl(const UnnamedGlobalConstantDecl *GCD);
1089
1090	/// Get the address of a template parameter object.
1091	ConstantAddress
1092	GetAddrOfTemplateParamObject(const TemplateParamObjectDecl *TPO);
1093
1094	/// Get the address of the thunk for the given global decl.
1095	llvm::Constant *GetAddrOfThunk(StringRef Name, llvm::Type *FnTy,
1096	GlobalDecl GD);
1097
1098	/// Get a reference to the target of VD.
1099	ConstantAddress GetWeakRefReference(const ValueDecl *VD);
1100
1101	/// Returns the assumed alignment of an opaque pointer to the given class.
1102	CharUnits getClassPointerAlignment(const CXXRecordDecl *CD);
1103
1104	/// Returns the minimum object size for an object of the given class type
1105	/// (or a class derived from it).
1106	CharUnits getMinimumClassObjectSize(const CXXRecordDecl *CD);
1107
1108	/// Returns the minimum object size for an object of the given type.
1109	CharUnits getMinimumObjectSize(QualType Ty) {
1110	if (CXXRecordDecl *RD = Ty->getAsCXXRecordDecl())
1111	return getMinimumClassObjectSize(CD: RD);
1112	return getContext().getTypeSizeInChars(T: Ty);
1113	}
1114
1115	/// Returns the assumed alignment of a virtual base of a class.
1116	CharUnits getVBaseAlignment(CharUnits DerivedAlign,
1117	const CXXRecordDecl *Derived,
1118	const CXXRecordDecl *VBase);
1119
1120	/// Given a class pointer with an actual known alignment, and the
1121	/// expected alignment of an object at a dynamic offset w.r.t that
1122	/// pointer, return the alignment to assume at the offset.
1123	CharUnits getDynamicOffsetAlignment(CharUnits ActualAlign,
1124	const CXXRecordDecl *Class,
1125	CharUnits ExpectedTargetAlign);
1126
1127	CharUnits
1128	computeNonVirtualBaseClassOffset(const CXXRecordDecl *DerivedClass,
1129	CastExpr::path_const_iterator Start,
1130	CastExpr::path_const_iterator End);
1131
1132	/// Returns the offset from a derived class to a class. Returns null if the
1133	/// offset is 0.
1134	llvm::Constant *
1135	GetNonVirtualBaseClassOffset(const CXXRecordDecl *ClassDecl,
1136	CastExpr::path_const_iterator PathBegin,
1137	CastExpr::path_const_iterator PathEnd);
1138
1139	llvm::FoldingSet<BlockByrefHelpers> ByrefHelpersCache;
1140
1141	/// Fetches the global unique block count.
1142	int getUniqueBlockCount() { return ++Block.GlobalUniqueCount; }
1143
1144	/// Fetches the type of a generic block descriptor.
1145	llvm::Type *getBlockDescriptorType();
1146
1147	/// The type of a generic block literal.
1148	llvm::Type *getGenericBlockLiteralType();
1149
1150	/// Gets the address of a block which requires no captures.
1151	llvm::Constant *GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name);
1152
1153	/// Returns the address of a block which requires no caputres, or null if
1154	/// we've yet to emit the block for BE.
1155	llvm::Constant *getAddrOfGlobalBlockIfEmitted(const BlockExpr *BE) {
1156	return EmittedGlobalBlocks.lookup(Val: BE);
1157	}
1158
1159	/// Notes that BE's global block is available via Addr. Asserts that BE
1160	/// isn't already emitted.
1161	void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr);
1162
1163	/// Return a pointer to a constant CFString object for the given string.
1164	ConstantAddress GetAddrOfConstantCFString(const StringLiteral *Literal);
1165
1166	/// Return a constant array for the given string.
1167	llvm::Constant *GetConstantArrayFromStringLiteral(const StringLiteral *E);
1168
1169	/// Return a pointer to a constant array for the given string literal.
1170	ConstantAddress
1171	GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
1172	StringRef Name = ".str");
1173
1174	/// Return a pointer to a constant array for the given ObjCEncodeExpr node.
1175	ConstantAddress
1176	GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *);
1177
1178	/// Returns a pointer to a character array containing the literal and a
1179	/// terminating '\0' character. The result has pointer to array type.
1180	///
1181	/// \param GlobalName If provided, the name to use for the global (if one is
1182	/// created).
1183	ConstantAddress
1184	GetAddrOfConstantCString(const std::string &Str,
1185	const char *GlobalName = nullptr);
1186
1187	/// Returns a pointer to a constant global variable for the given file-scope
1188	/// compound literal expression.
1189	ConstantAddress GetAddrOfConstantCompoundLiteral(const CompoundLiteralExpr*E);
1190
1191	/// If it's been emitted already, returns the GlobalVariable corresponding to
1192	/// a compound literal. Otherwise, returns null.
1193	llvm::GlobalVariable *
1194	getAddrOfConstantCompoundLiteralIfEmitted(const CompoundLiteralExpr *E);
1195
1196	/// Notes that CLE's GlobalVariable is GV. Asserts that CLE isn't already
1197	/// emitted.
1198	void setAddrOfConstantCompoundLiteral(const CompoundLiteralExpr *CLE,
1199	llvm::GlobalVariable *GV);
1200
1201	/// Returns a pointer to a global variable representing a temporary
1202	/// with static or thread storage duration.
1203	ConstantAddress GetAddrOfGlobalTemporary(const MaterializeTemporaryExpr *E,
1204	const Expr *Inner);
1205
1206	/// Retrieve the record type that describes the state of an
1207	/// Objective-C fast enumeration loop (for..in).
1208	QualType getObjCFastEnumerationStateType();
1209
1210	// Produce code for this constructor/destructor. This method doesn't try
1211	// to apply any ABI rules about which other constructors/destructors
1212	// are needed or if they are alias to each other.
1213	llvm::Function *codegenCXXStructor(GlobalDecl GD);
1214
1215	/// Return the address of the constructor/destructor of the given type.
1216	llvm::Constant *
1217	getAddrOfCXXStructor(GlobalDecl GD, const CGFunctionInfo *FnInfo = nullptr,
1218	llvm::FunctionType *FnType = nullptr,
1219	bool DontDefer = false,
1220	ForDefinition_t IsForDefinition = NotForDefinition) {
1221	return cast<llvm::Constant>(Val: getAddrAndTypeOfCXXStructor(GD, FnInfo, FnType,
1222	DontDefer,
1223	IsForDefinition)
1224	.getCallee());
1225	}
1226
1227	llvm::FunctionCallee getAddrAndTypeOfCXXStructor(
1228	GlobalDecl GD, const CGFunctionInfo *FnInfo = nullptr,
1229	llvm::FunctionType *FnType = nullptr, bool DontDefer = false,
1230	ForDefinition_t IsForDefinition = NotForDefinition);
1231
1232	/// Given a builtin id for a function like "__builtin_fabsf", return a
1233	/// Function* for "fabsf".
1234	llvm::Constant *getBuiltinLibFunction(const FunctionDecl *FD,
1235	unsigned BuiltinID);
1236
1237	llvm::Function *getIntrinsic(unsigned IID, ArrayRef<llvm::Type *> Tys = {});
1238
1239	void AddCXXGlobalInit(llvm::Function *F) { CXXGlobalInits.push_back(x: F); }
1240
1241	/// Emit code for a single top level declaration.
1242	void EmitTopLevelDecl(Decl *D);
1243
1244	/// Stored a deferred empty coverage mapping for an unused
1245	/// and thus uninstrumented top level declaration.
1246	void AddDeferredUnusedCoverageMapping(Decl *D);
1247
1248	/// Remove the deferred empty coverage mapping as this
1249	/// declaration is actually instrumented.
1250	void ClearUnusedCoverageMapping(const Decl *D);
1251
1252	/// Emit all the deferred coverage mappings
1253	/// for the uninstrumented functions.
1254	void EmitDeferredUnusedCoverageMappings();
1255
1256	/// Emit an alias for "main" if it has no arguments (needed for wasm).
1257	void EmitMainVoidAlias();
1258
1259	/// Tell the consumer that this variable has been instantiated.
1260	void HandleCXXStaticMemberVarInstantiation(VarDecl *VD);
1261
1262	/// If the declaration has internal linkage but is inside an
1263	/// extern "C" linkage specification, prepare to emit an alias for it
1264	/// to the expected name.
1265	template<typename SomeDecl>
1266	void MaybeHandleStaticInExternC(const SomeDecl *D, llvm::GlobalValue *GV);
1267
1268	/// Add a global to a list to be added to the llvm.used metadata.
1269	void addUsedGlobal(llvm::GlobalValue *GV);
1270
1271	/// Add a global to a list to be added to the llvm.compiler.used metadata.
1272	void addCompilerUsedGlobal(llvm::GlobalValue *GV);
1273
1274	/// Add a global to a list to be added to the llvm.compiler.used metadata.
1275	void addUsedOrCompilerUsedGlobal(llvm::GlobalValue *GV);
1276
1277	/// Add a destructor and object to add to the C++ global destructor function.
1278	void AddCXXDtorEntry(llvm::FunctionCallee DtorFn, llvm::Constant *Object) {
1279	CXXGlobalDtorsOrStermFinalizers.emplace_back(Args: DtorFn.getFunctionType(),
1280	Args: DtorFn.getCallee(), Args&: Object);
1281	}
1282
1283	/// Add an sterm finalizer to the C++ global cleanup function.
1284	void AddCXXStermFinalizerEntry(llvm::FunctionCallee DtorFn) {
1285	CXXGlobalDtorsOrStermFinalizers.emplace_back(Args: DtorFn.getFunctionType(),
1286	Args: DtorFn.getCallee(), Args: nullptr);
1287	}
1288
1289	/// Add an sterm finalizer to its own llvm.global_dtors entry.
1290	void AddCXXStermFinalizerToGlobalDtor(llvm::Function *StermFinalizer,
1291	int Priority) {
1292	AddGlobalDtor(Dtor: StermFinalizer, Priority);
1293	}
1294
1295	void AddCXXPrioritizedStermFinalizerEntry(llvm::Function *StermFinalizer,
1296	int Priority) {
1297	OrderGlobalInitsOrStermFinalizers Key(Priority,
1298	PrioritizedCXXStermFinalizers.size());
1299	PrioritizedCXXStermFinalizers.push_back(
1300	Elt: std::make_pair(x&: Key, y&: StermFinalizer));
1301	}
1302
1303	/// Create or return a runtime function declaration with the specified type
1304	/// and name. If \p AssumeConvergent is true, the call will have the
1305	/// convergent attribute added.
1306	///
1307	/// For new code, please use the overload that takes a QualType; it sets
1308	/// function attributes more accurately.
1309	llvm::FunctionCallee
1310	CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name,
1311	llvm::AttributeList ExtraAttrs = llvm::AttributeList(),
1312	bool Local = false, bool AssumeConvergent = false);
1313
1314	/// Create or return a runtime function declaration with the specified type
1315	/// and name. If \p AssumeConvergent is true, the call will have the
1316	/// convergent attribute added.
1317	llvm::FunctionCallee
1318	CreateRuntimeFunction(QualType ReturnTy, ArrayRef<QualType> ArgTys,
1319	StringRef Name,
1320	llvm::AttributeList ExtraAttrs = llvm::AttributeList(),
1321	bool Local = false, bool AssumeConvergent = false);
1322
1323	/// Create a new runtime global variable with the specified type and name.
1324	llvm::Constant *CreateRuntimeVariable(llvm::Type *Ty,
1325	StringRef Name);
1326
1327	///@name Custom Blocks Runtime Interfaces
1328	///@{
1329
1330	llvm::Constant *getNSConcreteGlobalBlock();
1331	llvm::Constant *getNSConcreteStackBlock();
1332	llvm::FunctionCallee getBlockObjectAssign();
1333	llvm::FunctionCallee getBlockObjectDispose();
1334
1335	///@}
1336
1337	llvm::Function *getLLVMLifetimeStartFn();
1338	llvm::Function *getLLVMLifetimeEndFn();
1339	llvm::Function *getLLVMFakeUseFn();
1340
1341	// Make sure that this type is translated.
1342	void UpdateCompletedType(const TagDecl *TD);
1343
1344	llvm::Constant *getMemberPointerConstant(const UnaryOperator *e);
1345
1346	/// Emit type info if type of an expression is a variably modified
1347	/// type. Also emit proper debug info for cast types.
1348	void EmitExplicitCastExprType(const ExplicitCastExpr *E,
1349	CodeGenFunction *CGF = nullptr);
1350
1351	/// Return the result of value-initializing the given type, i.e. a null
1352	/// expression of the given type. This is usually, but not always, an LLVM
1353	/// null constant.
1354	llvm::Constant *EmitNullConstant(QualType T);
1355
1356	/// Return a null constant appropriate for zero-initializing a base class with
1357	/// the given type. This is usually, but not always, an LLVM null constant.
1358	llvm::Constant *EmitNullConstantForBase(const CXXRecordDecl *Record);
1359
1360	/// Emit a general error that something can't be done.
1361	void Error(SourceLocation loc, StringRef error);
1362
1363	/// Print out an error that codegen doesn't support the specified stmt yet.
1364	void ErrorUnsupported(const Stmt *S, const char *Type);
1365
1366	/// Print out an error that codegen doesn't support the specified decl yet.
1367	void ErrorUnsupported(const Decl *D, const char *Type);
1368
1369	/// Run some code with "sufficient" stack space. (Currently, at least 256K is
1370	/// guaranteed). Produces a warning if we're low on stack space and allocates
1371	/// more in that case. Use this in code that may recurse deeply to avoid stack
1372	/// overflow.
1373	void runWithSufficientStackSpace(SourceLocation Loc,
1374	llvm::function_ref<void()> Fn);
1375
1376	/// Set the attributes on the LLVM function for the given decl and function
1377	/// info. This applies attributes necessary for handling the ABI as well as
1378	/// user specified attributes like section.
1379	void SetInternalFunctionAttributes(GlobalDecl GD, llvm::Function *F,
1380	const CGFunctionInfo &FI);
1381
1382	/// Set the LLVM function attributes (sext, zext, etc).
1383	void SetLLVMFunctionAttributes(GlobalDecl GD, const CGFunctionInfo &Info,
1384	llvm::Function *F, bool IsThunk);
1385
1386	/// Set the LLVM function attributes which only apply to a function
1387	/// definition.
1388	void SetLLVMFunctionAttributesForDefinition(const Decl *D, llvm::Function *F);
1389
1390	/// Set the LLVM function attributes that represent floating point
1391	/// environment.
1392	void setLLVMFunctionFEnvAttributes(const FunctionDecl *D, llvm::Function *F);
1393
1394	/// Return true iff the given type uses 'sret' when used as a return type.
1395	bool ReturnTypeUsesSRet(const CGFunctionInfo &FI);
1396
1397	/// Return true iff the given type has `inreg` set.
1398	bool ReturnTypeHasInReg(const CGFunctionInfo &FI);
1399
1400	/// Return true iff the given type uses an argument slot when 'sret' is used
1401	/// as a return type.
1402	bool ReturnSlotInterferesWithArgs(const CGFunctionInfo &FI);
1403
1404	/// Return true iff the given type uses 'fpret' when used as a return type.
1405	bool ReturnTypeUsesFPRet(QualType ResultType);
1406
1407	/// Return true iff the given type uses 'fp2ret' when used as a return type.
1408	bool ReturnTypeUsesFP2Ret(QualType ResultType);
1409
1410	/// Get the LLVM attributes and calling convention to use for a particular
1411	/// function type.
1412	///
1413	/// \param Name - The function name.
1414	/// \param Info - The function type information.
1415	/// \param CalleeInfo - The callee information these attributes are being
1416	/// constructed for. If valid, the attributes applied to this decl may
1417	/// contribute to the function attributes and calling convention.
1418	/// \param Attrs [out] - On return, the attribute list to use.
1419	/// \param CallingConv [out] - On return, the LLVM calling convention to use.
1420	void ConstructAttributeList(StringRef Name, const CGFunctionInfo &Info,
1421	CGCalleeInfo CalleeInfo,
1422	llvm::AttributeList &Attrs, unsigned &CallingConv,
1423	bool AttrOnCallSite, bool IsThunk);
1424
1425	/// Adjust Memory attribute to ensure that the BE gets the right attribute
1426	// in order to generate the library call or the intrinsic for the function
1427	// name 'Name'.
1428	void AdjustMemoryAttribute(StringRef Name, CGCalleeInfo CalleeInfo,
1429	llvm::AttributeList &Attrs);
1430
1431	/// Like the overload taking a `Function &`, but intended specifically
1432	/// for frontends that want to build on Clang's target-configuration logic.
1433	void addDefaultFunctionDefinitionAttributes(llvm::AttrBuilder &attrs);
1434
1435	StringRef getMangledName(GlobalDecl GD);
1436	StringRef getBlockMangledName(GlobalDecl GD, const BlockDecl *BD);
1437	const GlobalDecl getMangledNameDecl(StringRef);
1438
1439	void EmitTentativeDefinition(const VarDecl *D);
1440
1441	void EmitExternalDeclaration(const DeclaratorDecl *D);
1442
1443	void EmitVTable(CXXRecordDecl *Class);
1444
1445	void RefreshTypeCacheForClass(const CXXRecordDecl *Class);
1446
1447	/// Appends Opts to the "llvm.linker.options" metadata value.
1448	void AppendLinkerOptions(StringRef Opts);
1449
1450	/// Appends a detect mismatch command to the linker options.
1451	void AddDetectMismatch(StringRef Name, StringRef Value);
1452
1453	/// Appends a dependent lib to the appropriate metadata value.
1454	void AddDependentLib(StringRef Lib);
1455
1456
1457	llvm::GlobalVariable::LinkageTypes getFunctionLinkage(GlobalDecl GD);
1458
1459	void setFunctionLinkage(GlobalDecl GD, llvm::Function *F) {
1460	F->setLinkage(getFunctionLinkage(GD));
1461	}
1462
1463	/// Return the appropriate linkage for the vtable, VTT, and type information
1464	/// of the given class.
1465	llvm::GlobalVariable::LinkageTypes getVTableLinkage(const CXXRecordDecl *RD);
1466
1467	/// Return the store size, in character units, of the given LLVM type.
1468	CharUnits GetTargetTypeStoreSize(llvm::Type *Ty) const;
1469
1470	/// Returns LLVM linkage for a declarator.
1471	llvm::GlobalValue::LinkageTypes
1472	getLLVMLinkageForDeclarator(const DeclaratorDecl *D, GVALinkage Linkage);
1473
1474	/// Returns LLVM linkage for a declarator.
1475	llvm::GlobalValue::LinkageTypes
1476	getLLVMLinkageVarDefinition(const VarDecl *VD);
1477
1478	/// Emit all the global annotations.
1479	void EmitGlobalAnnotations();
1480
1481	/// Emit an annotation string.
1482	llvm::Constant *EmitAnnotationString(StringRef Str);
1483
1484	/// Emit the annotation's translation unit.
1485	llvm::Constant *EmitAnnotationUnit(SourceLocation Loc);
1486
1487	/// Emit the annotation line number.
1488	llvm::Constant *EmitAnnotationLineNo(SourceLocation L);
1489
1490	/// Emit additional args of the annotation.
1491	llvm::Constant *EmitAnnotationArgs(const AnnotateAttr *Attr);
1492
1493	/// Generate the llvm::ConstantStruct which contains the annotation
1494	/// information for a given GlobalValue. The annotation struct is
1495	/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the
1496	/// GlobalValue being annotated. The second field is the constant string
1497	/// created from the AnnotateAttr's annotation. The third field is a constant
1498	/// string containing the name of the translation unit. The fourth field is
1499	/// the line number in the file of the annotated value declaration.
1500	llvm::Constant *EmitAnnotateAttr(llvm::GlobalValue *GV,
1501	const AnnotateAttr *AA,
1502	SourceLocation L);
1503
1504	/// Add global annotations that are set on D, for the global GV. Those
1505	/// annotations are emitted during finalization of the LLVM code.
1506	void AddGlobalAnnotations(const ValueDecl *D, llvm::GlobalValue *GV);
1507
1508	bool isInNoSanitizeList(SanitizerMask Kind, llvm::Function *Fn,
1509	SourceLocation Loc) const;
1510
1511	bool isInNoSanitizeList(SanitizerMask Kind, llvm::GlobalVariable *GV,
1512	SourceLocation Loc, QualType Ty,
1513	StringRef Category = StringRef()) const;
1514
1515	/// Imbue XRay attributes to a function, applying the always/never attribute
1516	/// lists in the process. Returns true if we did imbue attributes this way,
1517	/// false otherwise.
1518	bool imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
1519	StringRef Category = StringRef()) const;
1520
1521	/// \returns true if \p Fn at \p Loc should be excluded from profile
1522	/// instrumentation by the SCL passed by \p -fprofile-list.
1523	ProfileList::ExclusionType
1524	isFunctionBlockedByProfileList(llvm::Function *Fn, SourceLocation Loc) const;
1525
1526	/// \returns true if \p Fn at \p Loc should be excluded from profile
1527	/// instrumentation.
1528	ProfileList::ExclusionType
1529	isFunctionBlockedFromProfileInstr(llvm::Function *Fn,
1530	SourceLocation Loc) const;
1531
1532	SanitizerMetadata *getSanitizerMetadata() {
1533	return SanitizerMD.get();
1534	}
1535
1536	void addDeferredVTable(const CXXRecordDecl *RD) {
1537	DeferredVTables.push_back(x: RD);
1538	}
1539
1540	/// Emit code for a single global function or var decl. Forward declarations
1541	/// are emitted lazily.
1542	void EmitGlobal(GlobalDecl D);
1543
1544	bool TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D);
1545
1546	llvm::GlobalValue *GetGlobalValue(StringRef Ref);
1547
1548	/// Set attributes which are common to any form of a global definition (alias,
1549	/// Objective-C method, function, global variable).
1550	///
1551	/// NOTE: This should only be called for definitions.
1552	void SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV);
1553
1554	void addReplacement(StringRef Name, llvm::Constant *C);
1555
1556	void addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C);
1557
1558	/// Emit a code for threadprivate directive.
1559	/// \param D Threadprivate declaration.
1560	void EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D);
1561
1562	/// Emit a code for declare reduction construct.
1563	void EmitOMPDeclareReduction(const OMPDeclareReductionDecl *D,
1564	CodeGenFunction *CGF = nullptr);
1565
1566	/// Emit a code for declare mapper construct.
1567	void EmitOMPDeclareMapper(const OMPDeclareMapperDecl *D,
1568	CodeGenFunction *CGF = nullptr);
1569
1570	// Emit code for the OpenACC Declare declaration.
1571	void EmitOpenACCDeclare(const OpenACCDeclareDecl *D,
1572	CodeGenFunction *CGF = nullptr);
1573	// Emit code for the OpenACC Routine declaration.
1574	void EmitOpenACCRoutine(const OpenACCRoutineDecl *D,
1575	CodeGenFunction *CGF = nullptr);
1576
1577	/// Emit a code for requires directive.
1578	/// \param D Requires declaration
1579	void EmitOMPRequiresDecl(const OMPRequiresDecl *D);
1580
1581	/// Emit a code for the allocate directive.
1582	/// \param D The allocate declaration
1583	void EmitOMPAllocateDecl(const OMPAllocateDecl *D);
1584
1585	/// Return the alignment specified in an allocate directive, if present.
1586	std::optional<CharUnits> getOMPAllocateAlignment(const VarDecl *VD);
1587
1588	/// Returns whether the given record has hidden LTO visibility and therefore
1589	/// may participate in (single-module) CFI and whole-program vtable
1590	/// optimization.
1591	bool HasHiddenLTOVisibility(const CXXRecordDecl *RD);
1592
1593	/// Returns whether the given record has public LTO visibility (regardless of
1594	/// -lto-whole-program-visibility) and therefore may not participate in
1595	/// (single-module) CFI and whole-program vtable optimization.
1596	bool AlwaysHasLTOVisibilityPublic(const CXXRecordDecl *RD);
1597
1598	/// Returns the vcall visibility of the given type. This is the scope in which
1599	/// a virtual function call could be made which ends up being dispatched to a
1600	/// member function of this class. This scope can be wider than the visibility
1601	/// of the class itself when the class has a more-visible dynamic base class.
1602	/// The client should pass in an empty Visited set, which is used to prevent
1603	/// redundant recursive processing.
1604	llvm::GlobalObject::VCallVisibility
1605	GetVCallVisibilityLevel(const CXXRecordDecl *RD,
1606	llvm::DenseSet<const CXXRecordDecl *> &Visited);
1607
1608	/// Emit type metadata for the given vtable using the given layout.
1609	void EmitVTableTypeMetadata(const CXXRecordDecl *RD,
1610	llvm::GlobalVariable *VTable,
1611	const VTableLayout &VTLayout);
1612
1613	llvm::Type *getVTableComponentType() const;
1614
1615	/// Generate a cross-DSO type identifier for MD.
1616	llvm::ConstantInt *CreateCrossDsoCfiTypeId(llvm::Metadata *MD);
1617
1618	/// Generate a KCFI type identifier for T.
1619	llvm::ConstantInt *CreateKCFITypeId(QualType T);
1620
1621	/// Create a metadata identifier for the given type. This may either be an
1622	/// MDString (for external identifiers) or a distinct unnamed MDNode (for
1623	/// internal identifiers).
1624	llvm::Metadata *CreateMetadataIdentifierForType(QualType T);
1625
1626	/// Create a metadata identifier that is intended to be used to check virtual
1627	/// calls via a member function pointer.
1628	llvm::Metadata *CreateMetadataIdentifierForVirtualMemPtrType(QualType T);
1629
1630	/// Create a metadata identifier for the generalization of the given type.
1631	/// This may either be an MDString (for external identifiers) or a distinct
1632	/// unnamed MDNode (for internal identifiers).
1633	llvm::Metadata *CreateMetadataIdentifierGeneralized(QualType T);
1634
1635	/// Create and attach type metadata to the given function.
1636	void createFunctionTypeMetadataForIcall(const FunctionDecl *FD,
1637	llvm::Function *F);
1638
1639	/// Set type metadata to the given function.
1640	void setKCFIType(const FunctionDecl *FD, llvm::Function *F);
1641
1642	/// Emit KCFI type identifier constants and remove unused identifiers.
1643	void finalizeKCFITypes();
1644
1645	/// Whether this function's return type has no side effects, and thus may
1646	/// be trivially discarded if it is unused.
1647	bool MayDropFunctionReturn(const ASTContext &Context,
1648	QualType ReturnType) const;
1649
1650	/// Returns whether this module needs the "all-vtables" type identifier.
1651	bool NeedAllVtablesTypeId() const;
1652
1653	/// Create and attach type metadata for the given vtable.
1654	void AddVTableTypeMetadata(llvm::GlobalVariable *VTable, CharUnits Offset,
1655	const CXXRecordDecl *RD);
1656
1657	/// Return a vector of most-base classes for RD. This is used to implement
1658	/// control flow integrity checks for member function pointers.
1659	///
1660	/// A most-base class of a class C is defined as a recursive base class of C,
1661	/// including C itself, that does not have any bases.
1662	SmallVector<const CXXRecordDecl *, 0>
1663	getMostBaseClasses(const CXXRecordDecl *RD);
1664
1665	/// Get the declaration of std::terminate for the platform.
1666	llvm::FunctionCallee getTerminateFn();
1667
1668	llvm::SanitizerStatReport &getSanStats();
1669
1670	llvm::Value *
1671	createOpenCLIntToSamplerConversion(const Expr *E, CodeGenFunction &CGF);
1672
1673	/// OpenCL v1.2 s5.6.4.6 allows the compiler to store kernel argument
1674	/// information in the program executable. The argument information stored
1675	/// includes the argument name, its type, the address and access qualifiers
1676	/// used. This helper can be used to generate metadata for source code kernel
1677	/// function as well as generated implicitly kernels. If a kernel is generated
1678	/// implicitly null value has to be passed to the last two parameters,
1679	/// otherwise all parameters must have valid non-null values.
1680	/// \param FN is a pointer to IR function being generated.
1681	/// \param FD is a pointer to function declaration if any.
1682	/// \param CGF is a pointer to CodeGenFunction that generates this function.
1683	void GenKernelArgMetadata(llvm::Function *FN,
1684	const FunctionDecl *FD = nullptr,
1685	CodeGenFunction *CGF = nullptr);
1686
1687	/// Get target specific null pointer.
1688	/// \param T is the LLVM type of the null pointer.
1689	/// \param QT is the clang QualType of the null pointer.
1690	llvm::Constant *getNullPointer(llvm::PointerType *T, QualType QT);
1691
1692	CharUnits getNaturalTypeAlignment(QualType T,
1693	LValueBaseInfo *BaseInfo = nullptr,
1694	TBAAAccessInfo *TBAAInfo = nullptr,
1695	bool forPointeeType = false);
1696	CharUnits getNaturalPointeeTypeAlignment(QualType T,
1697	LValueBaseInfo *BaseInfo = nullptr,
1698	TBAAAccessInfo *TBAAInfo = nullptr);
1699	bool stopAutoInit();
1700
1701	/// Print the postfix for externalized static variable or kernels for single
1702	/// source offloading languages CUDA and HIP. The unique postfix is created
1703	/// using either the CUID argument, or the file's UniqueID and active macros.
1704	/// The fallback method without a CUID requires that the offloading toolchain
1705	/// does not define separate macros via the -cc1 options.
1706	void printPostfixForExternalizedDecl(llvm::raw_ostream &OS,
1707	const Decl *D) const;
1708
1709	/// Move some lazily-emitted states to the NewBuilder. This is especially
1710	/// essential for the incremental parsing environment like Clang Interpreter,
1711	/// because we'll lose all important information after each repl.
1712	void moveLazyEmissionStates(CodeGenModule *NewBuilder);
1713
1714	/// Emit the IR encoding to attach the CUDA launch bounds attribute to \p F.
1715	/// If \p MaxThreadsVal is not nullptr, the max threads value is stored in it,
1716	/// if a valid one was found.
1717	void handleCUDALaunchBoundsAttr(llvm::Function *F,
1718	const CUDALaunchBoundsAttr *A,
1719	int32_t *MaxThreadsVal = nullptr,
1720	int32_t *MinBlocksVal = nullptr,
1721	int32_t *MaxClusterRankVal = nullptr);
1722
1723	/// Emit the IR encoding to attach the AMD GPU flat-work-group-size attribute
1724	/// to \p F. Alternatively, the work group size can be taken from a \p
1725	/// ReqdWGS. If \p MinThreadsVal is not nullptr, the min threads value is
1726	/// stored in it, if a valid one was found. If \p MaxThreadsVal is not
1727	/// nullptr, the max threads value is stored in it, if a valid one was found.
1728	void handleAMDGPUFlatWorkGroupSizeAttr(
1729	llvm::Function *F, const AMDGPUFlatWorkGroupSizeAttr *A,
1730	const ReqdWorkGroupSizeAttr *ReqdWGS = nullptr,
1731	int32_t *MinThreadsVal = nullptr, int32_t *MaxThreadsVal = nullptr);
1732
1733	/// Emit the IR encoding to attach the AMD GPU waves-per-eu attribute to \p F.
1734	void handleAMDGPUWavesPerEUAttr(llvm::Function *F,
1735	const AMDGPUWavesPerEUAttr *A);
1736
1737	llvm::Constant *
1738	GetOrCreateLLVMGlobal(StringRef MangledName, llvm::Type *Ty, LangAS AddrSpace,
1739	const VarDecl *D,
1740	ForDefinition_t IsForDefinition = NotForDefinition);
1741
1742	// FIXME: Hardcoding priority here is gross.
1743	void AddGlobalCtor(llvm::Function *Ctor, int Priority = 65535,
1744	unsigned LexOrder = ~0U,
1745	llvm::Constant *AssociatedData = nullptr);
1746	void AddGlobalDtor(llvm::Function *Dtor, int Priority = 65535,
1747	bool IsDtorAttrFunc = false);
1748
1749	// Return whether structured convergence intrinsics should be generated for
1750	// this target.
1751	bool shouldEmitConvergenceTokens() const {
1752	// TODO: this should probably become unconditional once the controlled
1753	// convergence becomes the norm.
1754	return getTriple().isSPIRVLogical();
1755	}
1756
1757	void addUndefinedGlobalForTailCall(
1758	std::pair<const FunctionDecl *, SourceLocation> Global) {
1759	MustTailCallUndefinedGlobals.insert(X: Global);
1760	}
1761
1762	bool shouldZeroInitPadding() const {
1763	// In C23 (N3096) $6.7.10:
1764	// """
1765	// If any object is initialized with an empty iniitializer, then it is
1766	// subject to default initialization:
1767	// - if it is an aggregate, every member is initialized (recursively)
1768	// according to these rules, and any padding is initialized to zero bits;
1769	// - if it is a union, the first named member is initialized (recursively)
1770	// according to these rules, and any padding is initialized to zero bits.
1771	//
1772	// If the aggregate or union contains elements or members that are
1773	// aggregates or unions, these rules apply recursively to the subaggregates
1774	// or contained unions.
1775	//
1776	// If there are fewer initializers in a brace-enclosed list than there are
1777	// elements or members of an aggregate, or fewer characters in a string
1778	// literal used to initialize an array of known size than there are elements
1779	// in the array, the remainder of the aggregate is subject to default
1780	// initialization.
1781	// """
1782	//
1783	// From my understanding, the standard is ambiguous in the following two
1784	// areas:
1785	// 1. For a union type with empty initializer, if the first named member is
1786	// not the largest member, then the bytes comes after the first named member
1787	// but before padding are left unspecified. An example is:
1788	// union U { int a; long long b;};
1789	// union U u = {}; // The first 4 bytes are 0, but 4-8 bytes are left
1790	// unspecified.
1791	//
1792	// 2. It only mentions padding for empty initializer, but doesn't mention
1793	// padding for a non empty initialization list. And if the aggregation or
1794	// union contains elements or members that are aggregates or unions, and
1795	// some are non empty initializers, while others are empty initiailizers,
1796	// the padding initialization is unclear. An example is:
1797	// struct S1 { int a; long long b; };
1798	// struct S2 { char c; struct S1 s1; };
1799	// // The values for paddings between s2.c and s2.s1.a, between s2.s1.a
1800	// and s2.s1.b are unclear.
1801	// struct S2 s2 = { 'c' };
1802	//
1803	// Here we choose to zero initiailize left bytes of a union type. Because
1804	// projects like the Linux kernel are relying on this behavior. If we don't
1805	// explicitly zero initialize them, the undef values can be optimized to
1806	// return gabage data. We also choose to zero initialize paddings for
1807	// aggregates and unions, no matter they are initialized by empty
1808	// initializers or non empty initializers. This can provide a consistent
1809	// behavior. So projects like the Linux kernel can rely on it.
1810	return !getLangOpts().CPlusPlus;
1811	}
1812
1813	// Helper to get the alignment for a variable.
1814	unsigned getVtableGlobalVarAlignment(const VarDecl *D = nullptr) {
1815	LangAS AS = GetGlobalVarAddressSpace(D);
1816	unsigned PAlign = getItaniumVTableContext().isRelativeLayout()
1817	? 32
1818	: getTarget().getPointerAlign(AddrSpace: AS);
1819	return PAlign;
1820	}
1821
1822	private:
1823	bool shouldDropDLLAttribute(const Decl *D, const llvm::GlobalValue *GV) const;
1824
1825	llvm::Constant *GetOrCreateLLVMFunction(
1826	StringRef MangledName, llvm::Type *Ty, GlobalDecl D, bool ForVTable,
1827	bool DontDefer = false, bool IsThunk = false,
1828	llvm::AttributeList ExtraAttrs = llvm::AttributeList(),
1829	ForDefinition_t IsForDefinition = NotForDefinition);
1830
1831	// Adds a declaration to the list of multi version functions if not present.
1832	void AddDeferredMultiVersionResolverToEmit(GlobalDecl GD);
1833
1834	// References to multiversion functions are resolved through an implicitly
1835	// defined resolver function. This function is responsible for creating
1836	// the resolver symbol for the provided declaration. The value returned
1837	// will be for an ifunc (llvm::GlobalIFunc) if the current target supports
1838	// that feature and for a regular function (llvm::GlobalValue) otherwise.
1839	llvm::Constant *GetOrCreateMultiVersionResolver(GlobalDecl GD);
1840
1841	// In scenarios where a function is not known to be a multiversion function
1842	// until a later declaration, it is sometimes necessary to change the
1843	// previously created mangled name to align with requirements of whatever
1844	// multiversion function kind the function is now known to be. This function
1845	// is responsible for performing such mangled name updates.
1846	void UpdateMultiVersionNames(GlobalDecl GD, const FunctionDecl *FD,
1847	StringRef &CurName);
1848
1849	bool GetCPUAndFeaturesAttributes(GlobalDecl GD,
1850	llvm::AttrBuilder &AttrBuilder,
1851	bool SetTargetFeatures = true);
1852	void setNonAliasAttributes(GlobalDecl GD, llvm::GlobalObject *GO);
1853
1854	/// Set function attributes for a function declaration.
1855	void SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
1856	bool IsIncompleteFunction, bool IsThunk);
1857
1858	void EmitGlobalDefinition(GlobalDecl D, llvm::GlobalValue *GV = nullptr);
1859
1860	void EmitGlobalFunctionDefinition(GlobalDecl GD, llvm::GlobalValue *GV);
1861	void EmitMultiVersionFunctionDefinition(GlobalDecl GD, llvm::GlobalValue *GV);
1862
1863	void EmitGlobalVarDefinition(const VarDecl *D, bool IsTentative = false);
1864	void EmitAliasDefinition(GlobalDecl GD);
1865	void emitIFuncDefinition(GlobalDecl GD);
1866	void emitCPUDispatchDefinition(GlobalDecl GD);
1867	void EmitObjCPropertyImplementations(const ObjCImplementationDecl *D);
1868	void EmitObjCIvarInitializations(ObjCImplementationDecl *D);
1869
1870	// C++ related functions.
1871
1872	void EmitDeclContext(const DeclContext *DC);
1873	void EmitLinkageSpec(const LinkageSpecDecl *D);
1874	void EmitTopLevelStmt(const TopLevelStmtDecl *D);
1875
1876	/// Emit the function that initializes C++ thread_local variables.
1877	void EmitCXXThreadLocalInitFunc();
1878
1879	/// Emit the function that initializes global variables for a C++ Module.
1880	void EmitCXXModuleInitFunc(clang::Module *Primary);
1881
1882	/// Emit the function that initializes C++ globals.
1883	void EmitCXXGlobalInitFunc();
1884
1885	/// Emit the function that performs cleanup associated with C++ globals.
1886	void EmitCXXGlobalCleanUpFunc();
1887
1888	/// Emit the function that initializes the specified global (if PerformInit is
1889	/// true) and registers its destructor.
1890	void EmitCXXGlobalVarDeclInitFunc(const VarDecl *D,
1891	llvm::GlobalVariable *Addr,
1892	bool PerformInit);
1893
1894	void EmitPointerToInitFunc(const VarDecl *VD, llvm::GlobalVariable *Addr,
1895	llvm::Function *InitFunc, InitSegAttr *ISA);
1896
1897	/// EmitCtorList - Generates a global array of functions and priorities using
1898	/// the given list and name. This array will have appending linkage and is
1899	/// suitable for use as a LLVM constructor or destructor array. Clears Fns.
1900	void EmitCtorList(CtorList &Fns, const char *GlobalName);
1901
1902	/// Emit any needed decls for which code generation was deferred.
1903	void EmitDeferred();
1904
1905	/// Try to emit external vtables as available_externally if they have emitted
1906	/// all inlined virtual functions. It runs after EmitDeferred() and therefore
1907	/// is not allowed to create new references to things that need to be emitted
1908	/// lazily.
1909	void EmitVTablesOpportunistically();
1910
1911	/// Call replaceAllUsesWith on all pairs in Replacements.
1912	void applyReplacements();
1913
1914	/// Call replaceAllUsesWith on all pairs in GlobalValReplacements.
1915	void applyGlobalValReplacements();
1916
1917	void checkAliases();
1918
1919	std::map<int, llvm::TinyPtrVector<llvm::Function *>> DtorsUsingAtExit;
1920
1921	/// Register functions annotated with __attribute__((destructor)) using
1922	/// __cxa_atexit, if it is available, or atexit otherwise.
1923	void registerGlobalDtorsWithAtExit();
1924
1925	// When using sinit and sterm functions, unregister
1926	// __attribute__((destructor)) annotated functions which were previously
1927	// registered by the atexit subroutine using unatexit.
1928	void unregisterGlobalDtorsWithUnAtExit();
1929
1930	/// Emit deferred multiversion function resolvers and associated variants.
1931	void emitMultiVersionFunctions();
1932
1933	/// Emit any vtables which we deferred and still have a use for.
1934	void EmitDeferredVTables();
1935
1936	/// Emit a dummy function that reference a CoreFoundation symbol when
1937	/// @available is used on Darwin.
1938	void emitAtAvailableLinkGuard();
1939
1940	/// Emit the llvm.used and llvm.compiler.used metadata.
1941	void emitLLVMUsed();
1942
1943	/// For C++20 Itanium ABI, emit the initializers for the module.
1944	void EmitModuleInitializers(clang::Module *Primary);
1945
1946	/// Emit the link options introduced by imported modules.
1947	void EmitModuleLinkOptions();
1948
1949	/// Helper function for EmitStaticExternCAliases() to redirect ifuncs that
1950	/// have a resolver name that matches 'Elem' to instead resolve to the name of
1951	/// 'CppFunc'. This redirection is necessary in cases where 'Elem' has a name
1952	/// that will be emitted as an alias of the name bound to 'CppFunc'; ifuncs
1953	/// may not reference aliases. Redirection is only performed if 'Elem' is only
1954	/// used by ifuncs in which case, 'Elem' is destroyed. 'true' is returned if
1955	/// redirection is successful, and 'false' is returned otherwise.
1956	bool CheckAndReplaceExternCIFuncs(llvm::GlobalValue *Elem,
1957	llvm::GlobalValue *CppFunc);
1958
1959	/// Emit aliases for internal-linkage declarations inside "C" language
1960	/// linkage specifications, giving them the "expected" name where possible.
1961	void EmitStaticExternCAliases();
1962
1963	void EmitDeclMetadata();
1964
1965	/// Emit the Clang version as llvm.ident metadata.
1966	void EmitVersionIdentMetadata();
1967
1968	/// Emit the Clang commandline as llvm.commandline metadata.
1969	void EmitCommandLineMetadata();
1970
1971	/// Emit the module flag metadata used to pass options controlling the
1972	/// the backend to LLVM.
1973	void EmitBackendOptionsMetadata(const CodeGenOptions &CodeGenOpts);
1974
1975	/// Emits OpenCL specific Metadata e.g. OpenCL version.
1976	void EmitOpenCLMetadata();
1977
1978	/// Emit the llvm.gcov metadata used to tell LLVM where to emit the .gcno and
1979	/// .gcda files in a way that persists in .bc files.
1980	void EmitCoverageFile();
1981
1982	/// Given a sycl_kernel_entry_point attributed function, emit the
1983	/// corresponding SYCL kernel caller offload entry point function.
1984	void EmitSYCLKernelCaller(const FunctionDecl *KernelEntryPointFn,
1985	ASTContext &Ctx);
1986
1987	/// Determine whether the definition must be emitted; if this returns \c
1988	/// false, the definition can be emitted lazily if it's used.
1989	bool MustBeEmitted(const ValueDecl *D);
1990
1991	/// Determine whether the definition can be emitted eagerly, or should be
1992	/// delayed until the end of the translation unit. This is relevant for
1993	/// definitions whose linkage can change, e.g. implicit function instantions
1994	/// which may later be explicitly instantiated.
1995	bool MayBeEmittedEagerly(const ValueDecl *D);
1996
1997	/// Check whether we can use a "simpler", more core exceptions personality
1998	/// function.
1999	void SimplifyPersonality();
2000
2001	/// Helper function for getDefaultFunctionAttributes. Builds a set of function
2002	/// attributes which can be simply added to a function.
2003	void getTrivialDefaultFunctionAttributes(StringRef Name, bool HasOptnone,
2004	bool AttrOnCallSite,
2005	llvm::AttrBuilder &FuncAttrs);
2006
2007	/// Helper function for ConstructAttributeList and
2008	/// addDefaultFunctionDefinitionAttributes. Builds a set of function
2009	/// attributes to add to a function with the given properties.
2010	void getDefaultFunctionAttributes(StringRef Name, bool HasOptnone,
2011	bool AttrOnCallSite,
2012	llvm::AttrBuilder &FuncAttrs);
2013
2014	llvm::Metadata *CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
2015	StringRef Suffix);
2016	};
2017
2018	} // end namespace CodeGen
2019	} // end namespace clang
2020
2021	#endif // LLVM_CLANG_LIB_CODEGEN_CODEGENMODULE_H
2022