1	//===- SourceManager.h - Track and cache source files -----------*- 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	/// \file
10	/// Defines the SourceManager interface.
11	///
12	/// There are three different types of locations in a %file: a spelling
13	/// location, an expansion location, and a presumed location.
14	///
15	/// Given an example of:
16	/// \code
17	/// #define min(x, y) x < y ? x : y
18	/// \endcode
19	///
20	/// and then later on a use of min:
21	/// \code
22	/// #line 17
23	/// return min(a, b);
24	/// \endcode
25	///
26	/// The expansion location is the line in the source code where the macro
27	/// was expanded (the return statement), the spelling location is the
28	/// location in the source where the macro was originally defined,
29	/// and the presumed location is where the line directive states that
30	/// the line is 17, or any other line.
31	//
32	//===----------------------------------------------------------------------===//
33
34	#ifndef LLVM_CLANG_BASIC_SOURCEMANAGER_H
35	#define LLVM_CLANG_BASIC_SOURCEMANAGER_H
36
37	#include "clang/Basic/Diagnostic.h"
38	#include "clang/Basic/FileEntry.h"
39	#include "clang/Basic/FileManager.h"
40	#include "clang/Basic/SourceLocation.h"
41	#include "llvm/ADT/ArrayRef.h"
42	#include "llvm/ADT/BitVector.h"
43	#include "llvm/ADT/DenseMap.h"
44	#include "llvm/ADT/DenseSet.h"
45	#include "llvm/ADT/IntrusiveRefCntPtr.h"
46	#include "llvm/ADT/PagedVector.h"
47	#include "llvm/ADT/PointerIntPair.h"
48	#include "llvm/ADT/SmallVector.h"
49	#include "llvm/ADT/StringRef.h"
50	#include "llvm/Support/Allocator.h"
51	#include "llvm/Support/Compiler.h"
52	#include "llvm/Support/MemoryBuffer.h"
53	#include <cassert>
54	#include <cstddef>
55	#include <map>
56	#include <memory>
57	#include <optional>
58	#include <string>
59	#include <utility>
60	#include <vector>
61
62	namespace clang {
63
64	class ASTReader;
65	class ASTWriter;
66	class FileManager;
67	class LineTableInfo;
68	class SourceManager;
69
70	/// Public enums and private classes that are part of the
71	/// SourceManager implementation.
72	namespace SrcMgr {
73
74	/// Indicates whether a file or directory holds normal user code,
75	/// system code, or system code which is implicitly 'extern "C"' in C++ mode.
76	///
77	/// Entire directories can be tagged with this (this is maintained by
78	/// DirectoryLookup and friends) as can specific FileInfos when a \#pragma
79	/// system_header is seen or in various other cases.
80	///
81	enum CharacteristicKind {
82	C_User,
83	C_System,
84	C_ExternCSystem,
85	C_User_ModuleMap,
86	C_System_ModuleMap
87	};
88
89	/// Determine whether a file / directory characteristic is for system code.
90	inline bool isSystem(CharacteristicKind CK) {
91	return CK != C_User && CK != C_User_ModuleMap;
92	}
93
94	/// Determine whether a file characteristic is for a module map.
95	inline bool isModuleMap(CharacteristicKind CK) {
96	return CK == C_User_ModuleMap || CK == C_System_ModuleMap;
97	}
98
99	/// Mapping of line offsets into a source file. This does not own the storage
100	/// for the line numbers.
101	class LineOffsetMapping {
102	public:
103	explicit operator bool() const { return Storage; }
104	unsigned size() const {
105	assert(Storage);
106	return Storage[0];
107	}
108	ArrayRef<unsigned> getLines() const {
109	assert(Storage);
110	return ArrayRef<unsigned>(Storage + 1, Storage + 1 + size());
111	}
112	const unsigned *begin() const { return getLines().begin(); }
113	const unsigned *end() const { return getLines().end(); }
114	const unsigned &operator[](int I) const { return getLines()[I]; }
115
116	static LineOffsetMapping get(llvm::MemoryBufferRef Buffer,
117	llvm::BumpPtrAllocator &Alloc);
118
119	LineOffsetMapping() = default;
120	LineOffsetMapping(ArrayRef<unsigned> LineOffsets,
121	llvm::BumpPtrAllocator &Alloc);
122
123	private:
124	/// First element is the size, followed by elements at off-by-one indexes.
125	unsigned *Storage = nullptr;
126	};
127
128	/// One instance of this struct is kept for every file loaded or used.
129	///
130	/// This object owns the MemoryBuffer object.
131	class alignas(8) ContentCache {
132	/// The actual buffer containing the characters from the input
133	/// file.
134	mutable std::unique_ptr<llvm::MemoryBuffer> Buffer;
135
136	public:
137	/// Reference to the file entry representing this ContentCache.
138	///
139	/// This reference does not own the FileEntry object.
140	///
141	/// It is possible for this to be NULL if the ContentCache encapsulates
142	/// an imaginary text buffer.
143	///
144	/// FIXME: Make non-optional using a virtual file as needed, remove \c
145	/// Filename and use \c OrigEntry.getNameAsRequested() instead.
146	OptionalFileEntryRef OrigEntry;
147
148	/// References the file which the contents were actually loaded from.
149	///
150	/// Can be different from 'Entry' if we overridden the contents of one file
151	/// with the contents of another file.
152	OptionalFileEntryRef ContentsEntry;
153
154	/// The filename that is used to access OrigEntry.
155	///
156	/// FIXME: Remove this once OrigEntry is a FileEntryRef with a stable name.
157	StringRef Filename;
158
159	/// A bump pointer allocated array of offsets for each source line.
160	///
161	/// This is lazily computed. The lines are owned by the SourceManager
162	/// BumpPointerAllocator object.
163	mutable LineOffsetMapping SourceLineCache;
164
165	/// Indicates whether the buffer itself was provided to override
166	/// the actual file contents.
167	///
168	/// When true, the original entry may be a virtual file that does not
169	/// exist.
170	LLVM_PREFERRED_TYPE(bool)
171	unsigned BufferOverridden : 1;
172
173	/// True if this content cache was initially created for a source file
174	/// considered to be volatile (likely to change between stat and open).
175	LLVM_PREFERRED_TYPE(bool)
176	unsigned IsFileVolatile : 1;
177
178	/// True if this file may be transient, that is, if it might not
179	/// exist at some later point in time when this content entry is used,
180	/// after serialization and deserialization.
181	LLVM_PREFERRED_TYPE(bool)
182	unsigned IsTransient : 1;
183
184	LLVM_PREFERRED_TYPE(bool)
185	mutable unsigned IsBufferInvalid : 1;
186
187	ContentCache()
188	: OrigEntry(std::nullopt), ContentsEntry(std::nullopt),
189	BufferOverridden(false), IsFileVolatile(false), IsTransient(false),
190	IsBufferInvalid(false) {}
191
192	ContentCache(FileEntryRef Ent) : ContentCache(Ent, Ent) {}
193
194	ContentCache(FileEntryRef Ent, FileEntryRef contentEnt)
195	: OrigEntry(Ent), ContentsEntry(contentEnt), BufferOverridden(false),
196	IsFileVolatile(false), IsTransient(false), IsBufferInvalid(false) {}
197
198	/// The copy ctor does not allow copies where source object has either
199	/// a non-NULL Buffer or SourceLineCache. Ownership of allocated memory
200	/// is not transferred, so this is a logical error.
201	ContentCache(const ContentCache &RHS)
202	: BufferOverridden(false), IsFileVolatile(false), IsTransient(false),
203	IsBufferInvalid(false) {
204	OrigEntry = RHS.OrigEntry;
205	ContentsEntry = RHS.ContentsEntry;
206
207	assert(!RHS.Buffer && !RHS.SourceLineCache &&
208	"Passed ContentCache object cannot own a buffer.");
209	}
210
211	ContentCache &operator=(const ContentCache &RHS) = delete;
212
213	/// Returns the memory buffer for the associated content.
214	///
215	/// \param Diag Object through which diagnostics will be emitted if the
216	/// buffer cannot be retrieved.
217	///
218	/// \param Loc If specified, is the location that invalid file diagnostics
219	/// will be emitted at.
220	std::optional<llvm::MemoryBufferRef>
221	getBufferOrNone(DiagnosticsEngine &Diag, FileManager &FM,
222	SourceLocation Loc = SourceLocation()) const;
223
224	/// Returns the size of the content encapsulated by this
225	/// ContentCache.
226	///
227	/// This can be the size of the source file or the size of an
228	/// arbitrary scratch buffer. If the ContentCache encapsulates a source
229	/// file this size is retrieved from the file's FileEntry.
230	unsigned getSize() const;
231
232	/// Returns the number of bytes actually mapped for this
233	/// ContentCache.
234	///
235	/// This can be 0 if the MemBuffer was not actually expanded.
236	unsigned getSizeBytesMapped() const;
237
238	/// Returns the kind of memory used to back the memory buffer for
239	/// this content cache. This is used for performance analysis.
240	llvm::MemoryBuffer::BufferKind getMemoryBufferKind() const;
241
242	/// Return the buffer, only if it has been loaded.
243	std::optional<llvm::MemoryBufferRef> getBufferIfLoaded() const {
244	if (Buffer)
245	return Buffer->getMemBufferRef();
246	return std::nullopt;
247	}
248
249	/// Return a StringRef to the source buffer data, only if it has already
250	/// been loaded.
251	std::optional<StringRef> getBufferDataIfLoaded() const {
252	if (Buffer)
253	return Buffer->getBuffer();
254	return std::nullopt;
255	}
256
257	/// Set the buffer.
258	void setBuffer(std::unique_ptr<llvm::MemoryBuffer> B) {
259	IsBufferInvalid = false;
260	Buffer = std::move(B);
261	}
262
263	/// Set the buffer to one that's not owned (or to nullptr).
264	///
265	/// \pre Buffer cannot already be set.
266	void setUnownedBuffer(std::optional<llvm::MemoryBufferRef> B) {
267	assert(!Buffer && "Expected to be called right after construction");
268	if (B)
269	setBuffer(llvm::MemoryBuffer::getMemBuffer(Ref: *B));
270	}
271
272	// If BufStr has an invalid BOM, returns the BOM name; otherwise, returns
273	// nullptr
274	static const char *getInvalidBOM(StringRef BufStr);
275	};
276
277	// Assert that the \c ContentCache objects will always be 8-byte aligned so
278	// that we can pack 3 bits of integer into pointers to such objects.
279	static_assert(alignof(ContentCache) >= 8,
280	"ContentCache must be 8-byte aligned.");
281
282	/// Information about a FileID, basically just the logical file
283	/// that it represents and include stack information.
284	///
285	/// Each FileInfo has include stack information, indicating where it came
286	/// from. This information encodes the \#include chain that a token was
287	/// expanded from. The main include file has an invalid IncludeLoc.
288	///
289	/// FileInfo should not grow larger than ExpansionInfo. Doing so will
290	/// cause memory to bloat in compilations with many unloaded macro
291	/// expansions, since the two data structurs are stored in a union in
292	/// SLocEntry. Extra fields should instead go in "ContentCache *", which
293	/// stores file contents and other bits on the side.
294	///
295	class FileInfo {
296	friend class clang::SourceManager;
297	friend class clang::ASTWriter;
298	friend class clang::ASTReader;
299
300	/// The location of the \#include that brought in this file.
301	///
302	/// This is an invalid SLOC for the main file (top of the \#include chain).
303	SourceLocation IncludeLoc;
304
305	/// Number of FileIDs (files and macros) that were created during
306	/// preprocessing of this \#include, including this SLocEntry.
307	///
308	/// Zero means the preprocessor didn't provide such info for this SLocEntry.
309	unsigned NumCreatedFIDs : 31;
310
311	/// Whether this FileInfo has any \#line directives.
312	LLVM_PREFERRED_TYPE(bool)
313	unsigned HasLineDirectives : 1;
314
315	/// The content cache and the characteristic of the file.
316	llvm::PointerIntPair<const ContentCache *, 3, CharacteristicKind>
317	ContentAndKind;
318
319	public:
320	/// Return a FileInfo object.
321	static FileInfo get(SourceLocation IL, ContentCache &Con,
322	CharacteristicKind FileCharacter, StringRef Filename) {
323	FileInfo X;
324	X.IncludeLoc = IL;
325	X.NumCreatedFIDs = 0;
326	X.HasLineDirectives = false;
327	X.ContentAndKind.setPointer(&Con);
328	X.ContentAndKind.setInt(FileCharacter);
329	Con.Filename = Filename;
330	return X;
331	}
332
333	SourceLocation getIncludeLoc() const {
334	return IncludeLoc;
335	}
336
337	const ContentCache &getContentCache() const {
338	return *ContentAndKind.getPointer();
339	}
340
341	/// Return whether this is a system header or not.
342	CharacteristicKind getFileCharacteristic() const {
343	return ContentAndKind.getInt();
344	}
345
346	/// Return true if this FileID has \#line directives in it.
347	bool hasLineDirectives() const { return HasLineDirectives; }
348
349	/// Set the flag that indicates that this FileID has
350	/// line table entries associated with it.
351	void setHasLineDirectives() { HasLineDirectives = true; }
352
353	/// Returns the name of the file that was used when the file was loaded from
354	/// the underlying file system.
355	StringRef getName() const { return getContentCache().Filename; }
356	};
357
358	/// Each ExpansionInfo encodes the expansion location - where
359	/// the token was ultimately expanded, and the SpellingLoc - where the actual
360	/// character data for the token came from.
361	class ExpansionInfo {
362	// Really these are all SourceLocations.
363
364	/// Where the spelling for the token can be found.
365	SourceLocation SpellingLoc;
366
367	/// In a macro expansion, ExpansionLocStart and ExpansionLocEnd
368	/// indicate the start and end of the expansion. In object-like macros,
369	/// they will be the same. In a function-like macro expansion, the start
370	/// will be the identifier and the end will be the ')'. Finally, in
371	/// macro-argument instantiations, the end will be 'SourceLocation()', an
372	/// invalid location.
373	SourceLocation ExpansionLocStart, ExpansionLocEnd;
374
375	/// Whether the expansion range is a token range.
376	bool ExpansionIsTokenRange;
377
378	public:
379	SourceLocation getSpellingLoc() const {
380	return SpellingLoc.isInvalid() ? getExpansionLocStart() : SpellingLoc;
381	}
382
383	SourceLocation getExpansionLocStart() const {
384	return ExpansionLocStart;
385	}
386
387	SourceLocation getExpansionLocEnd() const {
388	return ExpansionLocEnd.isInvalid() ? getExpansionLocStart()
389	: ExpansionLocEnd;
390	}
391
392	bool isExpansionTokenRange() const { return ExpansionIsTokenRange; }
393
394	CharSourceRange getExpansionLocRange() const {
395	return CharSourceRange(
396	SourceRange(getExpansionLocStart(), getExpansionLocEnd()),
397	isExpansionTokenRange());
398	}
399
400	bool isMacroArgExpansion() const {
401	// Note that this needs to return false for default constructed objects.
402	return getExpansionLocStart().isValid() && ExpansionLocEnd.isInvalid();
403	}
404
405	bool isMacroBodyExpansion() const {
406	return getExpansionLocStart().isValid() && ExpansionLocEnd.isValid();
407	}
408
409	bool isFunctionMacroExpansion() const {
410	return getExpansionLocStart().isValid() &&
411	getExpansionLocStart() != getExpansionLocEnd();
412	}
413
414	/// Return a ExpansionInfo for an expansion.
415	///
416	/// Start and End specify the expansion range (where the macro is
417	/// expanded), and SpellingLoc specifies the spelling location (where
418	/// the characters from the token come from). All three can refer to
419	/// normal File SLocs or expansion locations.
420	static ExpansionInfo create(SourceLocation SpellingLoc, SourceLocation Start,
421	SourceLocation End,
422	bool ExpansionIsTokenRange = true) {
423	ExpansionInfo X;
424	X.SpellingLoc = SpellingLoc;
425	X.ExpansionLocStart = Start;
426	X.ExpansionLocEnd = End;
427	X.ExpansionIsTokenRange = ExpansionIsTokenRange;
428	return X;
429	}
430
431	/// Return a special ExpansionInfo for the expansion of
432	/// a macro argument into a function-like macro's body.
433	///
434	/// ExpansionLoc specifies the expansion location (where the macro is
435	/// expanded). This doesn't need to be a range because a macro is always
436	/// expanded at a macro parameter reference, and macro parameters are
437	/// always exactly one token. SpellingLoc specifies the spelling location
438	/// (where the characters from the token come from). ExpansionLoc and
439	/// SpellingLoc can both refer to normal File SLocs or expansion locations.
440	///
441	/// Given the code:
442	/// \code
443	/// #define F(x) f(x)
444	/// F(42);
445	/// \endcode
446	///
447	/// When expanding '\c F(42)', the '\c x' would call this with an
448	/// SpellingLoc pointing at '\c 42' and an ExpansionLoc pointing at its
449	/// location in the definition of '\c F'.
450	static ExpansionInfo createForMacroArg(SourceLocation SpellingLoc,
451	SourceLocation ExpansionLoc) {
452	// We store an intentionally invalid source location for the end of the
453	// expansion range to mark that this is a macro argument location rather
454	// than a normal one.
455	return create(SpellingLoc, Start: ExpansionLoc, End: SourceLocation());
456	}
457
458	/// Return a special ExpansionInfo representing a token that ends
459	/// prematurely. This is used to model a '>>' token that has been split
460	/// into '>' tokens and similar cases. Unlike for the other forms of
461	/// expansion, the expansion range in this case is a character range, not
462	/// a token range.
463	static ExpansionInfo createForTokenSplit(SourceLocation SpellingLoc,
464	SourceLocation Start,
465	SourceLocation End) {
466	return create(SpellingLoc, Start, End, ExpansionIsTokenRange: false);
467	}
468	};
469
470	// Assert that the \c FileInfo objects are no bigger than \c ExpansionInfo
471	// objects. This controls the size of \c SLocEntry, of which we have one for
472	// each macro expansion. The number of (unloaded) macro expansions can be
473	// very large. Any other fields needed in FileInfo should go in ContentCache.
474	static_assert(sizeof(FileInfo) <= sizeof(ExpansionInfo),
475	"FileInfo must be no larger than ExpansionInfo.");
476
477	/// This is a discriminated union of FileInfo and ExpansionInfo.
478	///
479	/// SourceManager keeps an array of these objects, and they are uniquely
480	/// identified by the FileID datatype.
481	class SLocEntry {
482	static constexpr int OffsetBits = 8 * sizeof(SourceLocation::UIntTy) - 1;
483	SourceLocation::UIntTy Offset : OffsetBits;
484	LLVM_PREFERRED_TYPE(bool)
485	SourceLocation::UIntTy IsExpansion : 1;
486	union {
487	FileInfo File;
488	ExpansionInfo Expansion;
489	};
490
491	public:
492	SLocEntry() : Offset(), IsExpansion(), File() {}
493
494	SourceLocation::UIntTy getOffset() const { return Offset; }
495
496	bool isExpansion() const { return IsExpansion; }
497	bool isFile() const { return !isExpansion(); }
498
499	const FileInfo &getFile() const {
500	return const_cast<SLocEntry *>(this)->getFile();
501	}
502
503	FileInfo &getFile() {
504	assert(isFile() && "Not a file SLocEntry!");
505	return File;
506	}
507
508	const ExpansionInfo &getExpansion() const {
509	assert(isExpansion() && "Not a macro expansion SLocEntry!");
510	return Expansion;
511	}
512
513	/// Creates an incomplete SLocEntry that is only able to report its offset.
514	static SLocEntry getOffsetOnly(SourceLocation::UIntTy Offset) {
515	assert(!(Offset & (1ULL << OffsetBits)) && "Offset is too large");
516	SLocEntry E;
517	E.Offset = Offset;
518	return E;
519	}
520
521	static SLocEntry get(SourceLocation::UIntTy Offset, const FileInfo &FI) {
522	assert(!(Offset & (1ULL << OffsetBits)) && "Offset is too large");
523	SLocEntry E;
524	E.Offset = Offset;
525	E.IsExpansion = false;
526	E.File = FI;
527	return E;
528	}
529
530	static SLocEntry get(SourceLocation::UIntTy Offset,
531	const ExpansionInfo &Expansion) {
532	assert(!(Offset & (1ULL << OffsetBits)) && "Offset is too large");
533	SLocEntry E;
534	E.Offset = Offset;
535	E.IsExpansion = true;
536	new (&E.Expansion) ExpansionInfo(Expansion);
537	return E;
538	}
539	};
540
541	} // namespace SrcMgr
542
543	/// External source of source location entries.
544	class ExternalSLocEntrySource {
545	public:
546	virtual ~ExternalSLocEntrySource();
547
548	/// Read the source location entry with index ID, which will always be
549	/// less than -1.
550	///
551	/// \returns true if an error occurred that prevented the source-location
552	/// entry from being loaded.
553	virtual bool ReadSLocEntry(int ID) = 0;
554
555	/// Get the index ID for the loaded SourceLocation offset.
556	///
557	/// \returns Invalid index ID (0) if an error occurred that prevented the
558	/// SLocEntry from being loaded.
559	virtual int getSLocEntryID(SourceLocation::UIntTy SLocOffset) = 0;
560
561	/// Retrieve the module import location and name for the given ID, if
562	/// in fact it was loaded from a module (rather than, say, a precompiled
563	/// header).
564	virtual std::pair<SourceLocation, StringRef> getModuleImportLoc(int ID) = 0;
565	};
566
567	/// Holds the cache used by isBeforeInTranslationUnit.
568	///
569	/// The cache structure is complex enough to be worth breaking out of
570	/// SourceManager.
571	class InBeforeInTUCacheEntry {
572	/// The FileID's of the cached query.
573	///
574	/// If these match up with a subsequent query, the result can be reused.
575	FileID LQueryFID, RQueryFID;
576
577	/// The relative order of FileIDs that the CommonFID *immediately* includes.
578	///
579	/// This is used to compare macro expansion locations.
580	bool LChildBeforeRChild;
581
582	/// The file found in common between the two \#include traces, i.e.,
583	/// the nearest common ancestor of the \#include tree.
584	FileID CommonFID;
585
586	/// The offset of the previous query in CommonFID.
587	///
588	/// Usually, this represents the location of the \#include for QueryFID, but
589	/// if LQueryFID is a parent of RQueryFID (or vice versa) then these can be a
590	/// random token in the parent.
591	unsigned LCommonOffset, RCommonOffset;
592
593	public:
594	InBeforeInTUCacheEntry() = default;
595	InBeforeInTUCacheEntry(FileID L, FileID R) : LQueryFID(L), RQueryFID(R) {
596	assert(L != R);
597	}
598
599	/// Return true if the currently cached values match up with
600	/// the specified LHS/RHS query.
601	///
602	/// If not, we can't use the cache.
603	bool isCacheValid() const {
604	return CommonFID.isValid();
605	}
606
607	/// If the cache is valid, compute the result given the
608	/// specified offsets in the LHS/RHS FileID's.
609	bool getCachedResult(unsigned LOffset, unsigned ROffset) const {
610	// If one of the query files is the common file, use the offset. Otherwise,
611	// use the #include loc in the common file.
612	if (LQueryFID != CommonFID) LOffset = LCommonOffset;
613	if (RQueryFID != CommonFID) ROffset = RCommonOffset;
614
615	// It is common for multiple macro expansions to be "included" from the same
616	// location (expansion location), in which case use the order of the FileIDs
617	// to determine which came first. This will also take care the case where
618	// one of the locations points at the inclusion/expansion point of the other
619	// in which case its FileID will come before the other.
620	if (LOffset == ROffset)
621	return LChildBeforeRChild;
622
623	return LOffset < ROffset;
624	}
625
626	/// Set up a new query.
627	/// If it matches the old query, we can keep the cached answer.
628	void setQueryFIDs(FileID LHS, FileID RHS) {
629	assert(LHS != RHS);
630	if (LQueryFID != LHS || RQueryFID != RHS) {
631	LQueryFID = LHS;
632	RQueryFID = RHS;
633	CommonFID = FileID();
634	}
635	}
636
637	void setCommonLoc(FileID commonFID, unsigned lCommonOffset,
638	unsigned rCommonOffset, bool LParentBeforeRParent) {
639	CommonFID = commonFID;
640	LCommonOffset = lCommonOffset;
641	RCommonOffset = rCommonOffset;
642	LChildBeforeRChild = LParentBeforeRParent;
643	}
644	};
645
646	/// The stack used when building modules on demand, which is used
647	/// to provide a link between the source managers of the different compiler
648	/// instances.
649	using ModuleBuildStack = ArrayRef<std::pair<std::string, FullSourceLoc>>;
650
651	/// This class handles loading and caching of source files into memory.
652	///
653	/// This object owns the MemoryBuffer objects for all of the loaded
654	/// files and assigns unique FileID's for each unique \#include chain.
655	///
656	/// The SourceManager can be queried for information about SourceLocation
657	/// objects, turning them into either spelling or expansion locations. Spelling
658	/// locations represent where the bytes corresponding to a token came from and
659	/// expansion locations represent where the location is in the user's view. In
660	/// the case of a macro expansion, for example, the spelling location indicates
661	/// where the expanded token came from and the expansion location specifies
662	/// where it was expanded.
663	class SourceManager : public RefCountedBase<SourceManager> {
664	/// DiagnosticsEngine object.
665	DiagnosticsEngine &Diag;
666
667	FileManager &FileMgr;
668
669	mutable llvm::BumpPtrAllocator ContentCacheAlloc;
670
671	/// Memoized information about all of the files tracked by this
672	/// SourceManager.
673	///
674	/// This map allows us to merge ContentCache entries based
675	/// on their FileEntry*. All ContentCache objects will thus have unique,
676	/// non-null, FileEntry pointers.
677	llvm::DenseMap<FileEntryRef, SrcMgr::ContentCache*> FileInfos;
678
679	/// True if the ContentCache for files that are overridden by other
680	/// files, should report the original file name. Defaults to true.
681	bool OverridenFilesKeepOriginalName = true;
682
683	/// True if non-system source files should be treated as volatile
684	/// (likely to change while trying to use them). Defaults to false.
685	bool UserFilesAreVolatile;
686
687	/// True if all files read during this compilation should be treated
688	/// as transient (may not be present in later compilations using a module
689	/// file created from this compilation). Defaults to false.
690	bool FilesAreTransient = false;
691
692	struct OverriddenFilesInfoTy {
693	/// Files that have been overridden with the contents from another
694	/// file.
695	llvm::DenseMap<const FileEntry *, FileEntryRef> OverriddenFiles;
696
697	/// Files that were overridden with a memory buffer.
698	llvm::DenseSet<const FileEntry *> OverriddenFilesWithBuffer;
699	};
700
701	/// Lazily create the object keeping overridden files info, since
702	/// it is uncommonly used.
703	std::unique_ptr<OverriddenFilesInfoTy> OverriddenFilesInfo;
704
705	OverriddenFilesInfoTy &getOverriddenFilesInfo() {
706	if (!OverriddenFilesInfo)
707	OverriddenFilesInfo.reset(p: new OverriddenFilesInfoTy);
708	return *OverriddenFilesInfo;
709	}
710
711	/// Information about various memory buffers that we have read in.
712	///
713	/// All FileEntry* within the stored ContentCache objects are NULL,
714	/// as they do not refer to a file.
715	std::vector<SrcMgr::ContentCache*> MemBufferInfos;
716
717	/// The table of SLocEntries that are local to this module.
718	///
719	/// Positive FileIDs are indexes into this table. Entry 0 indicates an invalid
720	/// expansion.
721	SmallVector<SrcMgr::SLocEntry, 0> LocalSLocEntryTable;
722	/// An in-parallel offset table, merely used for speeding up FileID lookup.
723	SmallVector<SourceLocation::UIntTy> LocalLocOffsetTable;
724
725	/// The table of SLocEntries that are loaded from other modules.
726	///
727	/// Negative FileIDs are indexes into this table. To get from ID to an index,
728	/// use (-ID - 2).
729	llvm::PagedVector<SrcMgr::SLocEntry, 32> LoadedSLocEntryTable;
730
731	/// For each allocation in LoadedSLocEntryTable, we keep the first FileID.
732	/// We assume exactly one allocation per AST file, and use that to determine
733	/// whether two FileIDs come from the same AST file.
734	SmallVector<FileID, 0> LoadedSLocEntryAllocBegin;
735
736	/// The starting offset of the next local SLocEntry.
737	///
738	/// This is LocalSLocEntryTable.back().Offset + the size of that entry.
739	SourceLocation::UIntTy NextLocalOffset;
740
741	/// The starting offset of the latest batch of loaded SLocEntries.
742	///
743	/// This is LoadedSLocEntryTable.back().Offset, except that that entry might
744	/// not have been loaded, so that value would be unknown.
745	SourceLocation::UIntTy CurrentLoadedOffset;
746
747	/// The highest possible offset is 2^31-1 (2^63-1 for 64-bit source
748	/// locations), so CurrentLoadedOffset starts at 2^31 (2^63 resp.).
749	static const SourceLocation::UIntTy MaxLoadedOffset =
750	1ULL << (8 * sizeof(SourceLocation::UIntTy) - 1);
751
752	/// A bitmap that indicates whether the entries of LoadedSLocEntryTable
753	/// have already been loaded from the external source.
754	///
755	/// Same indexing as LoadedSLocEntryTable.
756	llvm::BitVector SLocEntryLoaded;
757
758	/// A bitmap that indicates whether the entries of LoadedSLocEntryTable
759	/// have already had their offset loaded from the external source.
760	///
761	/// Superset of SLocEntryLoaded. Same indexing as SLocEntryLoaded.
762	llvm::BitVector SLocEntryOffsetLoaded;
763
764	/// An external source for source location entries.
765	ExternalSLocEntrySource *ExternalSLocEntries = nullptr;
766
767	/// A one-entry cache to speed up getFileID.
768	///
769	/// LastFileIDLookup records the last FileID looked up or created, because it
770	/// is very common to look up many tokens from the same file.
771	mutable FileID LastFileIDLookup;
772	mutable SourceLocation::UIntTy LastLookupStartOffset;
773	mutable SourceLocation::UIntTy LastLookupEndOffset; // exclude
774
775	/// Holds information for \#line directives.
776	///
777	/// This is referenced by indices from SLocEntryTable.
778	std::unique_ptr<LineTableInfo> LineTable;
779
780	/// These ivars serve as a cache used in the getLineNumber
781	/// method which is used to speedup getLineNumber calls to nearby locations.
782	mutable FileID LastLineNoFileIDQuery;
783	mutable const SrcMgr::ContentCache *LastLineNoContentCache;
784	mutable unsigned LastLineNoFilePos;
785	mutable unsigned LastLineNoResult;
786
787	/// The file ID for the main source file of the translation unit.
788	FileID MainFileID;
789
790	/// The file ID for the precompiled preamble there is one.
791	FileID PreambleFileID;
792
793	// Statistics for -print-stats.
794	mutable unsigned NumLinearScans = 0;
795	mutable unsigned NumBinaryProbes = 0;
796
797	/// Associates a FileID with its "included/expanded in" decomposed
798	/// location.
799	///
800	/// Used to cache results from and speed-up \c getDecomposedIncludedLoc
801	/// function.
802	mutable llvm::DenseMap<FileID, FileIDAndOffset> IncludedLocMap;
803
804	/// The key value into the IsBeforeInTUCache table.
805	using IsBeforeInTUCacheKey = std::pair<FileID, FileID>;
806
807	/// The IsBeforeInTranslationUnitCache is a mapping from FileID pairs
808	/// to cache results.
809	using InBeforeInTUCache =
810	llvm::DenseMap<IsBeforeInTUCacheKey, InBeforeInTUCacheEntry>;
811
812	/// Cache results for the isBeforeInTranslationUnit method.
813	mutable InBeforeInTUCache IBTUCache;
814	mutable InBeforeInTUCacheEntry IBTUCacheOverflow;
815
816	/// Return the cache entry for comparing the given file IDs
817	/// for isBeforeInTranslationUnit.
818	InBeforeInTUCacheEntry &getInBeforeInTUCache(FileID LFID, FileID RFID) const;
819
820	// Cache for the "fake" buffer used for error-recovery purposes.
821	mutable std::unique_ptr<llvm::MemoryBuffer> FakeBufferForRecovery;
822
823	mutable std::unique_ptr<SrcMgr::ContentCache> FakeContentCacheForRecovery;
824
825	mutable std::unique_ptr<SrcMgr::SLocEntry> FakeSLocEntryForRecovery;
826
827	/// Lazily computed map of macro argument chunks to their expanded
828	/// source location.
829	using MacroArgsMap = std::map<unsigned, SourceLocation>;
830
831	mutable llvm::DenseMap<FileID, std::unique_ptr<MacroArgsMap>>
832	MacroArgsCacheMap;
833
834	/// The stack of modules being built, which is used to detect
835	/// cycles in the module dependency graph as modules are being built, as
836	/// well as to describe why we're rebuilding a particular module.
837	///
838	/// There is no way to set this value from the command line. If we ever need
839	/// to do so (e.g., if on-demand module construction moves out-of-process),
840	/// we can add a cc1-level option to do so.
841	SmallVector<std::pair<std::string, FullSourceLoc>, 2> StoredModuleBuildStack;
842
843	public:
844	SourceManager(DiagnosticsEngine &Diag, FileManager &FileMgr,
845	bool UserFilesAreVolatile = false);
846	explicit SourceManager(const SourceManager &) = delete;
847	SourceManager &operator=(const SourceManager &) = delete;
848	~SourceManager();
849
850	void clearIDTables();
851
852	/// Initialize this source manager suitably to replay the compilation
853	/// described by \p Old. Requires that \p Old outlive \p *this.
854	void initializeForReplay(const SourceManager &Old);
855
856	DiagnosticsEngine &getDiagnostics() const { return Diag; }
857
858	FileManager &getFileManager() const { return FileMgr; }
859
860	/// Set true if the SourceManager should report the original file name
861	/// for contents of files that were overridden by other files. Defaults to
862	/// true.
863	void setOverridenFilesKeepOriginalName(bool value) {
864	OverridenFilesKeepOriginalName = value;
865	}
866
867	/// True if non-system source files should be treated as volatile
868	/// (likely to change while trying to use them).
869	bool userFilesAreVolatile() const { return UserFilesAreVolatile; }
870
871	/// Retrieve the module build stack.
872	ModuleBuildStack getModuleBuildStack() const {
873	return StoredModuleBuildStack;
874	}
875
876	/// Set the module build stack.
877	void setModuleBuildStack(ModuleBuildStack stack) {
878	StoredModuleBuildStack.clear();
879	StoredModuleBuildStack.append(in_start: stack.begin(), in_end: stack.end());
880	}
881
882	/// Push an entry to the module build stack.
883	void pushModuleBuildStack(StringRef moduleName, FullSourceLoc importLoc) {
884	StoredModuleBuildStack.push_back(Elt: std::make_pair(x: moduleName.str(),y&: importLoc));
885	}
886
887	//===--------------------------------------------------------------------===//
888	// MainFileID creation and querying methods.
889	//===--------------------------------------------------------------------===//
890
891	/// Returns the FileID of the main source file.
892	FileID getMainFileID() const { return MainFileID; }
893
894	/// Set the file ID for the main source file.
895	void setMainFileID(FileID FID) {
896	MainFileID = FID;
897	}
898
899	/// Returns true when the given FileEntry corresponds to the main file.
900	///
901	/// The main file should be set prior to calling this function.
902	bool isMainFile(const FileEntry &SourceFile);
903
904	/// Set the file ID for the precompiled preamble.
905	void setPreambleFileID(FileID Preamble) {
906	assert(PreambleFileID.isInvalid() && "PreambleFileID already set!");
907	PreambleFileID = Preamble;
908	}
909
910	/// Get the file ID for the precompiled preamble if there is one.
911	FileID getPreambleFileID() const { return PreambleFileID; }
912
913	//===--------------------------------------------------------------------===//
914	// Methods to create new FileID's and macro expansions.
915	//===--------------------------------------------------------------------===//
916
917	/// Create a new FileID that represents the specified file
918	/// being \#included from the specified IncludePosition.
919	FileID createFileID(FileEntryRef SourceFile, SourceLocation IncludePos,
920	SrcMgr::CharacteristicKind FileCharacter,
921	int LoadedID = 0,
922	SourceLocation::UIntTy LoadedOffset = 0);
923
924	/// Create a new FileID that represents the specified memory buffer.
925	///
926	/// This does no caching of the buffer and takes ownership of the
927	/// MemoryBuffer, so only pass a MemoryBuffer to this once.
928	FileID createFileID(std::unique_ptr<llvm::MemoryBuffer> Buffer,
929	SrcMgr::CharacteristicKind FileCharacter = SrcMgr::C_User,
930	int LoadedID = 0, SourceLocation::UIntTy LoadedOffset = 0,
931	SourceLocation IncludeLoc = SourceLocation());
932
933	/// Create a new FileID that represents the specified memory buffer.
934	///
935	/// This does not take ownership of the MemoryBuffer. The memory buffer must
936	/// outlive the SourceManager.
937	FileID createFileID(const llvm::MemoryBufferRef &Buffer,
938	SrcMgr::CharacteristicKind FileCharacter = SrcMgr::C_User,
939	int LoadedID = 0, SourceLocation::UIntTy LoadedOffset = 0,
940	SourceLocation IncludeLoc = SourceLocation());
941
942	/// Get the FileID for \p SourceFile if it exists. Otherwise, create a
943	/// new FileID for the \p SourceFile.
944	FileID getOrCreateFileID(FileEntryRef SourceFile,
945	SrcMgr::CharacteristicKind FileCharacter);
946
947	/// Creates an expansion SLocEntry for the substitution of an argument into a
948	/// function-like macro's body. Returns the start of the expansion.
949	///
950	/// The macro argument was written at \p SpellingLoc with length \p Length.
951	/// \p ExpansionLoc is the parameter name in the (expanded) macro body.
952	SourceLocation createMacroArgExpansionLoc(SourceLocation SpellingLoc,
953	SourceLocation ExpansionLoc,
954	unsigned Length);
955
956	/// Creates an expansion SLocEntry for a macro use. Returns its start.
957	///
958	/// The macro body begins at \p SpellingLoc with length \p Length.
959	/// The macro use spans [ExpansionLocStart, ExpansionLocEnd].
960	SourceLocation createExpansionLoc(SourceLocation SpellingLoc,
961	SourceLocation ExpansionLocStart,
962	SourceLocation ExpansionLocEnd,
963	unsigned Length,
964	bool ExpansionIsTokenRange = true,
965	int LoadedID = 0,
966	SourceLocation::UIntTy LoadedOffset = 0);
967
968	/// Return a new SourceLocation that encodes that the token starting
969	/// at \p TokenStart ends prematurely at \p TokenEnd.
970	SourceLocation createTokenSplitLoc(SourceLocation SpellingLoc,
971	SourceLocation TokenStart,
972	SourceLocation TokenEnd);
973
974	/// Retrieve the memory buffer associated with the given file.
975	///
976	/// Returns std::nullopt if the buffer is not valid.
977	std::optional<llvm::MemoryBufferRef>
978	getMemoryBufferForFileOrNone(FileEntryRef File);
979
980	/// Retrieve the memory buffer associated with the given file.
981	///
982	/// Returns a fake buffer if there isn't a real one.
983	llvm::MemoryBufferRef getMemoryBufferForFileOrFake(FileEntryRef File) {
984	if (auto B = getMemoryBufferForFileOrNone(File))
985	return *B;
986	return getFakeBufferForRecovery();
987	}
988
989	/// Override the contents of the given source file by providing an
990	/// already-allocated buffer.
991	///
992	/// \param SourceFile the source file whose contents will be overridden.
993	///
994	/// \param Buffer the memory buffer whose contents will be used as the
995	/// data in the given source file.
996	void overrideFileContents(FileEntryRef SourceFile,
997	const llvm::MemoryBufferRef &Buffer) {
998	overrideFileContents(SourceFile, Buffer: llvm::MemoryBuffer::getMemBuffer(Ref: Buffer));
999	}
1000
1001	/// Override the contents of the given source file by providing an
1002	/// already-allocated buffer.
1003	///
1004	/// \param SourceFile the source file whose contents will be overridden.
1005	///
1006	/// \param Buffer the memory buffer whose contents will be used as the
1007	/// data in the given source file.
1008	void overrideFileContents(FileEntryRef SourceFile,
1009	std::unique_ptr<llvm::MemoryBuffer> Buffer);
1010
1011	/// Override the given source file with another one.
1012	///
1013	/// \param SourceFile the source file which will be overridden.
1014	///
1015	/// \param NewFile the file whose contents will be used as the
1016	/// data instead of the contents of the given source file.
1017	void overrideFileContents(const FileEntry *SourceFile, FileEntryRef NewFile);
1018
1019	/// Returns true if the file contents have been overridden.
1020	bool isFileOverridden(const FileEntry *File) const {
1021	if (OverriddenFilesInfo) {
1022	if (OverriddenFilesInfo->OverriddenFilesWithBuffer.count(V: File))
1023	return true;
1024	if (OverriddenFilesInfo->OverriddenFiles.contains(Val: File))
1025	return true;
1026	}
1027	return false;
1028	}
1029
1030	/// Bypass the overridden contents of a file. This creates a new FileEntry
1031	/// and initializes the content cache for it. Returns std::nullopt if there
1032	/// is no such file in the filesystem.
1033	///
1034	/// This should be called before parsing has begun.
1035	OptionalFileEntryRef bypassFileContentsOverride(FileEntryRef File);
1036
1037	/// Specify that a file is transient.
1038	void setFileIsTransient(FileEntryRef SourceFile);
1039
1040	/// Specify that all files that are read during this compilation are
1041	/// transient.
1042	void setAllFilesAreTransient(bool Transient) {
1043	FilesAreTransient = Transient;
1044	}
1045
1046	//===--------------------------------------------------------------------===//
1047	// FileID manipulation methods.
1048	//===--------------------------------------------------------------------===//
1049
1050	/// Return the buffer for the specified FileID.
1051	///
1052	/// If there is an error opening this buffer the first time, return
1053	/// std::nullopt.
1054	std::optional<llvm::MemoryBufferRef>
1055	getBufferOrNone(FileID FID, SourceLocation Loc = SourceLocation()) const {
1056	if (auto *Entry = getSLocEntryForFile(FID))
1057	return Entry->getFile().getContentCache().getBufferOrNone(
1058	Diag, FM&: getFileManager(), Loc);
1059	return std::nullopt;
1060	}
1061
1062	/// Return the buffer for the specified FileID.
1063	///
1064	/// If there is an error opening this buffer the first time, this
1065	/// manufactures a temporary buffer and returns it.
1066	llvm::MemoryBufferRef
1067	getBufferOrFake(FileID FID, SourceLocation Loc = SourceLocation()) const {
1068	if (auto B = getBufferOrNone(FID, Loc))
1069	return *B;
1070	return getFakeBufferForRecovery();
1071	}
1072
1073	/// Returns the FileEntry record for the provided FileID.
1074	const FileEntry *getFileEntryForID(FileID FID) const {
1075	if (auto FE = getFileEntryRefForID(FID))
1076	return *FE;
1077	return nullptr;
1078	}
1079
1080	/// Returns the FileEntryRef for the provided FileID.
1081	OptionalFileEntryRef getFileEntryRefForID(FileID FID) const {
1082	if (auto *Entry = getSLocEntryForFile(FID))
1083	return Entry->getFile().getContentCache().OrigEntry;
1084	return std::nullopt;
1085	}
1086
1087	/// Returns the filename for the provided FileID, unless it's a built-in
1088	/// buffer that's not represented by a filename.
1089	///
1090	/// Returns std::nullopt for non-files and built-in files.
1091	std::optional<StringRef> getNonBuiltinFilenameForID(FileID FID) const;
1092
1093	/// Returns the FileEntry record for the provided SLocEntry.
1094	const FileEntry *
1095	getFileEntryForSLocEntry(const SrcMgr::SLocEntry &SLocEntry) const {
1096	if (auto FE = SLocEntry.getFile().getContentCache().OrigEntry)
1097	return *FE;
1098	return nullptr;
1099	}
1100
1101	/// Return a StringRef to the source buffer data for the
1102	/// specified FileID.
1103	///
1104	/// \param FID The file ID whose contents will be returned.
1105	/// \param Invalid If non-NULL, will be set true if an error occurred.
1106	StringRef getBufferData(FileID FID, bool *Invalid = nullptr) const;
1107
1108	/// Return a StringRef to the source buffer data for the
1109	/// specified FileID, returning std::nullopt if invalid.
1110	///
1111	/// \param FID The file ID whose contents will be returned.
1112	std::optional<StringRef> getBufferDataOrNone(FileID FID) const;
1113
1114	/// Return a StringRef to the source buffer data for the
1115	/// specified FileID, returning std::nullopt if it's not yet loaded.
1116	///
1117	/// \param FID The file ID whose contents will be returned.
1118	std::optional<StringRef> getBufferDataIfLoaded(FileID FID) const;
1119
1120	/// Get the number of FileIDs (files and macros) that were created
1121	/// during preprocessing of \p FID, including it.
1122	unsigned getNumCreatedFIDsForFileID(FileID FID) const {
1123	if (auto *Entry = getSLocEntryForFile(FID))
1124	return Entry->getFile().NumCreatedFIDs;
1125	return 0;
1126	}
1127
1128	/// Set the number of FileIDs (files and macros) that were created
1129	/// during preprocessing of \p FID, including it.
1130	void setNumCreatedFIDsForFileID(FileID FID, unsigned NumFIDs,
1131	bool Force = false) {
1132	auto *Entry = getSLocEntryForFile(FID);
1133	if (!Entry)
1134	return;
1135	assert((Force || Entry->getFile().NumCreatedFIDs == 0) && "Already set!");
1136	Entry->getFile().NumCreatedFIDs = NumFIDs;
1137	}
1138
1139	//===--------------------------------------------------------------------===//
1140	// SourceLocation manipulation methods.
1141	//===--------------------------------------------------------------------===//
1142
1143	/// Return the FileID for a SourceLocation.
1144	///
1145	/// This is a very hot method that is used for all SourceManager queries
1146	/// that start with a SourceLocation object. It is responsible for finding
1147	/// the entry in SLocEntryTable which contains the specified location.
1148	///
1149	FileID getFileID(SourceLocation SpellingLoc) const {
1150	return getFileID(SLocOffset: SpellingLoc.getOffset());
1151	}
1152
1153	/// Return the filename of the file containing a SourceLocation.
1154	StringRef getFilename(SourceLocation SpellingLoc) const;
1155
1156	/// Return the source location corresponding to the first byte of
1157	/// the specified file.
1158	SourceLocation getLocForStartOfFile(FileID FID) const {
1159	if (auto *Entry = getSLocEntryForFile(FID))
1160	return SourceLocation::getFileLoc(ID: Entry->getOffset());
1161	return SourceLocation();
1162	}
1163
1164	/// Return the source location corresponding to the last byte of the
1165	/// specified file.
1166	SourceLocation getLocForEndOfFile(FileID FID) const {
1167	if (auto *Entry = getSLocEntryForFile(FID))
1168	return SourceLocation::getFileLoc(ID: Entry->getOffset() +
1169	getFileIDSize(FID));
1170	return SourceLocation();
1171	}
1172
1173	/// Returns the include location if \p FID is a \#include'd file
1174	/// otherwise it returns an invalid location.
1175	SourceLocation getIncludeLoc(FileID FID) const {
1176	if (auto *Entry = getSLocEntryForFile(FID))
1177	return Entry->getFile().getIncludeLoc();
1178	return SourceLocation();
1179	}
1180
1181	// Returns the import location if the given source location is
1182	// located within a module, or an invalid location if the source location
1183	// is within the current translation unit.
1184	std::pair<SourceLocation, StringRef>
1185	getModuleImportLoc(SourceLocation Loc) const {
1186	FileID FID = getFileID(SpellingLoc: Loc);
1187
1188	// Positive file IDs are in the current translation unit, and -1 is a
1189	// placeholder.
1190	if (FID.ID >= -1)
1191	return std::make_pair(x: SourceLocation(), y: "");
1192
1193	return ExternalSLocEntries->getModuleImportLoc(ID: FID.ID);
1194	}
1195
1196	/// Given a SourceLocation object \p Loc, return the expansion
1197	/// location referenced by the ID.
1198	SourceLocation getExpansionLoc(SourceLocation Loc) const {
1199	// Handle the non-mapped case inline, defer to out of line code to handle
1200	// expansions.
1201	if (Loc.isFileID()) return Loc;
1202	return getExpansionLocSlowCase(Loc);
1203	}
1204
1205	/// Given \p Loc, if it is a macro location return the expansion
1206	/// location or the spelling location, depending on if it comes from a
1207	/// macro argument or not.
1208	SourceLocation getFileLoc(SourceLocation Loc) const {
1209	if (Loc.isFileID()) return Loc;
1210	return getFileLocSlowCase(Loc);
1211	}
1212
1213	/// Return the start/end of the expansion information for an
1214	/// expansion location.
1215	///
1216	/// \pre \p Loc is required to be an expansion location.
1217	CharSourceRange getImmediateExpansionRange(SourceLocation Loc) const;
1218
1219	/// Given a SourceLocation object, return the range of
1220	/// tokens covered by the expansion in the ultimate file.
1221	CharSourceRange getExpansionRange(SourceLocation Loc) const;
1222
1223	/// Given a SourceRange object, return the range of
1224	/// tokens or characters covered by the expansion in the ultimate file.
1225	CharSourceRange getExpansionRange(SourceRange Range) const {
1226	SourceLocation Begin = getExpansionRange(Loc: Range.getBegin()).getBegin();
1227	CharSourceRange End = getExpansionRange(Loc: Range.getEnd());
1228	return CharSourceRange(SourceRange(Begin, End.getEnd()),
1229	End.isTokenRange());
1230	}
1231
1232	/// Given a CharSourceRange object, return the range of
1233	/// tokens or characters covered by the expansion in the ultimate file.
1234	CharSourceRange getExpansionRange(CharSourceRange Range) const {
1235	CharSourceRange Expansion = getExpansionRange(Range: Range.getAsRange());
1236	if (Expansion.getEnd() == Range.getEnd())
1237	Expansion.setTokenRange(Range.isTokenRange());
1238	return Expansion;
1239	}
1240
1241	/// Given a SourceLocation object, return the spelling
1242	/// location referenced by the ID.
1243	///
1244	/// This is the place where the characters that make up the lexed token
1245	/// can be found.
1246	SourceLocation getSpellingLoc(SourceLocation Loc) const {
1247	// Handle the non-mapped case inline, defer to out of line code to handle
1248	// expansions.
1249	if (Loc.isFileID()) return Loc;
1250	return getSpellingLocSlowCase(Loc);
1251	}
1252
1253	/// Given a SourceLocation object, return the spelling location
1254	/// referenced by the ID.
1255	///
1256	/// This is the first level down towards the place where the characters
1257	/// that make up the lexed token can be found. This should not generally
1258	/// be used by clients.
1259	SourceLocation getImmediateSpellingLoc(SourceLocation Loc) const;
1260
1261	/// Form a SourceLocation from a FileID and Offset pair.
1262	SourceLocation getComposedLoc(FileID FID, unsigned Offset) const {
1263	auto *Entry = getSLocEntryOrNull(FID);
1264	if (!Entry)
1265	return SourceLocation();
1266
1267	SourceLocation::UIntTy GlobalOffset = Entry->getOffset() + Offset;
1268	return Entry->isFile() ? SourceLocation::getFileLoc(ID: GlobalOffset)
1269	: SourceLocation::getMacroLoc(ID: GlobalOffset);
1270	}
1271
1272	/// Decompose the specified location into a raw FileID + Offset pair.
1273	///
1274	/// The first element is the FileID, the second is the offset from the
1275	/// start of the buffer of the location.
1276	FileIDAndOffset getDecomposedLoc(SourceLocation Loc) const {
1277	FileID FID = getFileID(SpellingLoc: Loc);
1278	auto *Entry = getSLocEntryOrNull(FID);
1279	if (!Entry)
1280	return std::make_pair(x: FileID(), y: 0);
1281	return std::make_pair(x&: FID, y: Loc.getOffset() - Entry->getOffset());
1282	}
1283
1284	/// Decompose the specified location into a raw FileID + Offset pair.
1285	///
1286	/// If the location is an expansion record, walk through it until we find
1287	/// the final location expanded.
1288	FileIDAndOffset getDecomposedExpansionLoc(SourceLocation Loc) const {
1289	FileID FID = getFileID(SpellingLoc: Loc);
1290	auto *E = getSLocEntryOrNull(FID);
1291	if (!E)
1292	return std::make_pair(x: FileID(), y: 0);
1293
1294	unsigned Offset = Loc.getOffset()-E->getOffset();
1295	if (Loc.isFileID())
1296	return std::make_pair(x&: FID, y&: Offset);
1297
1298	return getDecomposedExpansionLocSlowCase(E);
1299	}
1300
1301	/// Decompose the specified location into a raw FileID + Offset pair.
1302	///
1303	/// If the location is an expansion record, walk through it until we find
1304	/// its spelling record.
1305	FileIDAndOffset getDecomposedSpellingLoc(SourceLocation Loc) const {
1306	FileID FID = getFileID(SpellingLoc: Loc);
1307	auto *E = getSLocEntryOrNull(FID);
1308	if (!E)
1309	return std::make_pair(x: FileID(), y: 0);
1310
1311	unsigned Offset = Loc.getOffset()-E->getOffset();
1312	if (Loc.isFileID())
1313	return std::make_pair(x&: FID, y&: Offset);
1314	return getDecomposedSpellingLocSlowCase(E, Offset);
1315	}
1316
1317	/// Returns the "included/expanded in" decomposed location of the given
1318	/// FileID.
1319	FileIDAndOffset getDecomposedIncludedLoc(FileID FID) const;
1320
1321	/// Returns the offset from the start of the file that the
1322	/// specified SourceLocation represents.
1323	///
1324	/// This is not very meaningful for a macro ID.
1325	unsigned getFileOffset(SourceLocation SpellingLoc) const {
1326	return getDecomposedLoc(Loc: SpellingLoc).second;
1327	}
1328
1329	/// Tests whether the given source location represents a macro
1330	/// argument's expansion into the function-like macro definition.
1331	///
1332	/// \param StartLoc If non-null and function returns true, it is set to the
1333	/// start location of the macro argument expansion.
1334	///
1335	/// Such source locations only appear inside of the expansion
1336	/// locations representing where a particular function-like macro was
1337	/// expanded.
1338	bool isMacroArgExpansion(SourceLocation Loc,
1339	SourceLocation *StartLoc = nullptr) const;
1340
1341	/// Tests whether the given source location represents the expansion of
1342	/// a macro body.
1343	///
1344	/// This is equivalent to testing whether the location is part of a macro
1345	/// expansion but not the expansion of an argument to a function-like macro.
1346	bool isMacroBodyExpansion(SourceLocation Loc) const;
1347
1348	/// Returns true if the given MacroID location points at the beginning
1349	/// of the immediate macro expansion.
1350	///
1351	/// \param MacroBegin If non-null and function returns true, it is set to the
1352	/// begin location of the immediate macro expansion.
1353	bool isAtStartOfImmediateMacroExpansion(SourceLocation Loc,
1354	SourceLocation *MacroBegin = nullptr) const;
1355
1356	/// Returns true if the given MacroID location points at the character
1357	/// end of the immediate macro expansion.
1358	///
1359	/// \param MacroEnd If non-null and function returns true, it is set to the
1360	/// character end location of the immediate macro expansion.
1361	bool
1362	isAtEndOfImmediateMacroExpansion(SourceLocation Loc,
1363	SourceLocation *MacroEnd = nullptr) const;
1364
1365	/// Returns true if \p Loc is inside the [\p Start, +\p Length)
1366	/// chunk of the source location address space.
1367	///
1368	/// If it's true and \p RelativeOffset is non-null, it will be set to the
1369	/// relative offset of \p Loc inside the chunk.
1370	bool
1371	isInSLocAddrSpace(SourceLocation Loc, SourceLocation Start, unsigned Length,
1372	SourceLocation::UIntTy *RelativeOffset = nullptr) const {
1373	assert(((Start.getOffset() < NextLocalOffset &&
1374	Start.getOffset()+Length <= NextLocalOffset) ||
1375	(Start.getOffset() >= CurrentLoadedOffset &&
1376	Start.getOffset()+Length < MaxLoadedOffset)) &&
1377	"Chunk is not valid SLoc address space");
1378	SourceLocation::UIntTy LocOffs = Loc.getOffset();
1379	SourceLocation::UIntTy BeginOffs = Start.getOffset();
1380	SourceLocation::UIntTy EndOffs = BeginOffs + Length;
1381	if (LocOffs >= BeginOffs && LocOffs < EndOffs) {
1382	if (RelativeOffset)
1383	*RelativeOffset = LocOffs - BeginOffs;
1384	return true;
1385	}
1386
1387	return false;
1388	}
1389
1390	/// Return true if both \p LHS and \p RHS are in the local source
1391	/// location address space or the loaded one.
1392	///
1393	/// If it's true and \p RelativeOffset is non-null, it will be set to the
1394	/// offset of \p RHS relative to \p LHS.
1395	bool isInSameSLocAddrSpace(SourceLocation LHS, SourceLocation RHS,
1396	SourceLocation::IntTy *RelativeOffset) const {
1397	SourceLocation::UIntTy LHSOffs = LHS.getOffset(), RHSOffs = RHS.getOffset();
1398	bool LHSLoaded = LHSOffs >= CurrentLoadedOffset;
1399	bool RHSLoaded = RHSOffs >= CurrentLoadedOffset;
1400
1401	if (LHSLoaded == RHSLoaded) {
1402	if (RelativeOffset)
1403	*RelativeOffset = RHSOffs - LHSOffs;
1404	return true;
1405	}
1406
1407	return false;
1408	}
1409
1410	//===--------------------------------------------------------------------===//
1411	// Queries about the code at a SourceLocation.
1412	//===--------------------------------------------------------------------===//
1413
1414	/// Return a pointer to the start of the specified location
1415	/// in the appropriate spelling MemoryBuffer.
1416	///
1417	/// \param Invalid If non-NULL, will be set \c true if an error occurs.
1418	const char *getCharacterData(SourceLocation SL,
1419	bool *Invalid = nullptr) const;
1420
1421	/// Return the column # for the specified file position.
1422	///
1423	/// This is significantly cheaper to compute than the line number. This
1424	/// returns zero if the column number isn't known. This may only be called
1425	/// on a file sloc, so you must choose a spelling or expansion location
1426	/// before calling this method.
1427	unsigned getColumnNumber(FileID FID, unsigned FilePos,
1428	bool *Invalid = nullptr) const;
1429	unsigned getSpellingColumnNumber(SourceLocation Loc,
1430	bool *Invalid = nullptr) const;
1431	unsigned getExpansionColumnNumber(SourceLocation Loc,
1432	bool *Invalid = nullptr) const;
1433	unsigned getPresumedColumnNumber(SourceLocation Loc,
1434	bool *Invalid = nullptr) const;
1435
1436	/// Given a SourceLocation, return the spelling line number
1437	/// for the position indicated.
1438	///
1439	/// This requires building and caching a table of line offsets for the
1440	/// MemoryBuffer, so this is not cheap: use only when about to emit a
1441	/// diagnostic.
1442	unsigned getLineNumber(FileID FID, unsigned FilePos, bool *Invalid = nullptr) const;
1443	unsigned getSpellingLineNumber(SourceLocation Loc, bool *Invalid = nullptr) const;
1444	unsigned getExpansionLineNumber(SourceLocation Loc, bool *Invalid = nullptr) const;
1445	unsigned getPresumedLineNumber(SourceLocation Loc, bool *Invalid = nullptr) const;
1446
1447	/// Return the filename or buffer identifier of the buffer the
1448	/// location is in.
1449	///
1450	/// Note that this name does not respect \#line directives. Use
1451	/// getPresumedLoc for normal clients.
1452	StringRef getBufferName(SourceLocation Loc, bool *Invalid = nullptr) const;
1453
1454	/// Return the file characteristic of the specified source
1455	/// location, indicating whether this is a normal file, a system
1456	/// header, or an "implicit extern C" system header.
1457	///
1458	/// This state can be modified with flags on GNU linemarker directives like:
1459	/// \code
1460	/// # 4 "foo.h" 3
1461	/// \endcode
1462	/// which changes all source locations in the current file after that to be
1463	/// considered to be from a system header.
1464	SrcMgr::CharacteristicKind getFileCharacteristic(SourceLocation Loc) const;
1465
1466	/// Returns the "presumed" location of a SourceLocation specifies.
1467	///
1468	/// A "presumed location" can be modified by \#line or GNU line marker
1469	/// directives. This provides a view on the data that a user should see
1470	/// in diagnostics, for example.
1471	///
1472	/// Note that a presumed location is always given as the expansion point of
1473	/// an expansion location, not at the spelling location.
1474	///
1475	/// \returns The presumed location of the specified SourceLocation. If the
1476	/// presumed location cannot be calculated (e.g., because \p Loc is invalid
1477	/// or the file containing \p Loc has changed on disk), returns an invalid
1478	/// presumed location.
1479	PresumedLoc getPresumedLoc(SourceLocation Loc,
1480	bool UseLineDirectives = true) const;
1481
1482	/// Returns whether the PresumedLoc for a given SourceLocation is
1483	/// in the main file.
1484	///
1485	/// This computes the "presumed" location for a SourceLocation, then checks
1486	/// whether it came from a file other than the main file. This is different
1487	/// from isWrittenInMainFile() because it takes line marker directives into
1488	/// account.
1489	bool isInMainFile(SourceLocation Loc) const;
1490
1491	/// Returns true if the spelling locations for both SourceLocations
1492	/// are part of the same file buffer.
1493	///
1494	/// This check ignores line marker directives.
1495	bool isWrittenInSameFile(SourceLocation Loc1, SourceLocation Loc2) const {
1496	return getFileID(SpellingLoc: Loc1) == getFileID(SpellingLoc: Loc2);
1497	}
1498
1499	/// Returns true if the spelling location for the given location
1500	/// is in the main file buffer.
1501	///
1502	/// This check ignores line marker directives.
1503	bool isWrittenInMainFile(SourceLocation Loc) const {
1504	return getFileID(SpellingLoc: Loc) == getMainFileID();
1505	}
1506
1507	/// Returns whether \p Loc is located in a <built-in> file.
1508	bool isWrittenInBuiltinFile(SourceLocation Loc) const {
1509	PresumedLoc Presumed = getPresumedLoc(Loc);
1510	if (Presumed.isInvalid())
1511	return false;
1512	StringRef Filename(Presumed.getFilename());
1513	return Filename == "<built-in>";
1514	}
1515
1516	/// Returns whether \p Loc is located in a <command line> file.
1517	bool isWrittenInCommandLineFile(SourceLocation Loc) const {
1518	PresumedLoc Presumed = getPresumedLoc(Loc);
1519	if (Presumed.isInvalid())
1520	return false;
1521	StringRef Filename(Presumed.getFilename());
1522	return Filename == "<command line>";
1523	}
1524
1525	/// Returns whether \p Loc is located in a <scratch space> file.
1526	bool isWrittenInScratchSpace(SourceLocation Loc) const {
1527	PresumedLoc Presumed = getPresumedLoc(Loc);
1528	if (Presumed.isInvalid())
1529	return false;
1530	StringRef Filename(Presumed.getFilename());
1531	return Filename == "<scratch space>";
1532	}
1533
1534	/// Returns whether \p Loc is located in a built-in or command line source.
1535	bool isInPredefinedFile(SourceLocation Loc) const {
1536	PresumedLoc Presumed = getPresumedLoc(Loc);
1537	if (Presumed.isInvalid())
1538	return false;
1539	StringRef Filename(Presumed.getFilename());
1540	return Filename == "<built-in>" || Filename == "<command line>";
1541	}
1542
1543	/// Returns if a SourceLocation is in a system header.
1544	bool isInSystemHeader(SourceLocation Loc) const {
1545	if (Loc.isInvalid())
1546	return false;
1547	return isSystem(CK: getFileCharacteristic(Loc));
1548	}
1549
1550	/// Returns if a SourceLocation is in an "extern C" system header.
1551	bool isInExternCSystemHeader(SourceLocation Loc) const {
1552	return getFileCharacteristic(Loc) == SrcMgr::C_ExternCSystem;
1553	}
1554
1555	/// Returns whether \p Loc is expanded from a macro in a system header.
1556	bool isInSystemMacro(SourceLocation loc) const {
1557	if (!loc.isMacroID())
1558	return false;
1559
1560	// This happens when the macro is the result of a paste, in that case
1561	// its spelling is the scratch memory, so we take the parent context.
1562	// There can be several level of token pasting.
1563	if (isWrittenInScratchSpace(Loc: getSpellingLoc(Loc: loc))) {
1564	do {
1565	loc = getImmediateMacroCallerLoc(Loc: loc);
1566	} while (isWrittenInScratchSpace(Loc: getSpellingLoc(Loc: loc)));
1567	return isInSystemMacro(loc);
1568	}
1569
1570	return isInSystemHeader(Loc: getSpellingLoc(Loc: loc));
1571	}
1572
1573	/// The size of the SLocEntry that \p FID represents.
1574	unsigned getFileIDSize(FileID FID) const;
1575
1576	/// Given a specific FileID, returns true if \p Loc is inside that
1577	/// FileID chunk and sets relative offset (offset of \p Loc from beginning
1578	/// of FileID) to \p relativeOffset.
1579	bool isInFileID(SourceLocation Loc, FileID FID,
1580	unsigned *RelativeOffset = nullptr) const {
1581	SourceLocation::UIntTy Offs = Loc.getOffset();
1582	if (isOffsetInFileID(FID, SLocOffset: Offs)) {
1583	if (RelativeOffset)
1584	*RelativeOffset = Offs - getSLocEntry(FID).getOffset();
1585	return true;
1586	}
1587
1588	return false;
1589	}
1590
1591	//===--------------------------------------------------------------------===//
1592	// Line Table Manipulation Routines
1593	//===--------------------------------------------------------------------===//
1594
1595	/// Return the uniqued ID for the specified filename.
1596	unsigned getLineTableFilenameID(StringRef Str);
1597
1598	/// Add a line note to the line table for the FileID and offset
1599	/// specified by Loc.
1600	///
1601	/// If FilenameID is -1, it is considered to be unspecified.
1602	void AddLineNote(SourceLocation Loc, unsigned LineNo, int FilenameID,
1603	bool IsFileEntry, bool IsFileExit,
1604	SrcMgr::CharacteristicKind FileKind);
1605
1606	/// Determine if the source manager has a line table.
1607	bool hasLineTable() const { return LineTable != nullptr; }
1608
1609	/// Retrieve the stored line table.
1610	LineTableInfo &getLineTable();
1611
1612	//===--------------------------------------------------------------------===//
1613	// Queries for performance analysis.
1614	//===--------------------------------------------------------------------===//
1615
1616	/// Return the total amount of physical memory allocated by the
1617	/// ContentCache allocator.
1618	size_t getContentCacheSize() const {
1619	return ContentCacheAlloc.getTotalMemory();
1620	}
1621
1622	struct MemoryBufferSizes {
1623	const size_t malloc_bytes;
1624	const size_t mmap_bytes;
1625
1626	MemoryBufferSizes(size_t malloc_bytes, size_t mmap_bytes)
1627	: malloc_bytes(malloc_bytes), mmap_bytes(mmap_bytes) {}
1628	};
1629
1630	/// Return the amount of memory used by memory buffers, breaking down
1631	/// by heap-backed versus mmap'ed memory.
1632	MemoryBufferSizes getMemoryBufferSizes() const;
1633
1634	/// Return the amount of memory used for various side tables and
1635	/// data structures in the SourceManager.
1636	size_t getDataStructureSizes() const;
1637
1638	//===--------------------------------------------------------------------===//
1639	// Other miscellaneous methods.
1640	//===--------------------------------------------------------------------===//
1641
1642	/// Get the source location for the given file:line:col triplet.
1643	///
1644	/// If the source file is included multiple times, the source location will
1645	/// be based upon the first inclusion.
1646	SourceLocation translateFileLineCol(const FileEntry *SourceFile,
1647	unsigned Line, unsigned Col) const;
1648
1649	/// Get the FileID for the given file.
1650	///
1651	/// If the source file is included multiple times, the FileID will be the
1652	/// first inclusion.
1653	FileID translateFile(const FileEntry *SourceFile) const;
1654	FileID translateFile(FileEntryRef SourceFile) const {
1655	return translateFile(SourceFile: &SourceFile.getFileEntry());
1656	}
1657
1658	/// Get the source location in \p FID for the given line:col.
1659	/// Returns null location if \p FID is not a file SLocEntry.
1660	SourceLocation translateLineCol(FileID FID,
1661	unsigned Line, unsigned Col) const;
1662
1663	/// If \p Loc points inside a function macro argument, the returned
1664	/// location will be the macro location in which the argument was expanded.
1665	/// If a macro argument is used multiple times, the expanded location will
1666	/// be at the first expansion of the argument.
1667	/// e.g.
1668	/// MY_MACRO(foo);
1669	/// ^
1670	/// Passing a file location pointing at 'foo', will yield a macro location
1671	/// where 'foo' was expanded into.
1672	SourceLocation getMacroArgExpandedLocation(SourceLocation Loc) const;
1673
1674	/// Determines the order of 2 source locations in the translation unit.
1675	///
1676	/// \returns true if LHS source location comes before RHS, false otherwise.
1677	bool isBeforeInTranslationUnit(SourceLocation LHS, SourceLocation RHS) const;
1678
1679	/// Determines whether the two decomposed source location is in the
1680	/// same translation unit. As a byproduct, it also calculates the order
1681	/// of the source locations in case they are in the same TU.
1682	///
1683	/// \returns Pair of bools the first component is true if the two locations
1684	/// are in the same TU. The second bool is true if the first is true
1685	/// and \p LOffs is before \p ROffs.
1686	std::pair<bool, bool>
1687	isInTheSameTranslationUnit(FileIDAndOffset &LOffs,
1688	FileIDAndOffset &ROffs) const;
1689
1690	/// \param Loc a source location in a loaded AST (of a PCH/Module file).
1691	/// \returns a FileID uniquely identifies the AST of a loaded
1692	/// module/PCH where `Loc` is at.
1693	FileID getUniqueLoadedASTFileID(SourceLocation Loc) const;
1694
1695	/// Determines whether the two decomposed source location is in the same TU.
1696	bool isInTheSameTranslationUnitImpl(const FileIDAndOffset &LOffs,
1697	const FileIDAndOffset &ROffs) const;
1698
1699	/// Determines the order of 2 source locations in the "source location
1700	/// address space".
1701	bool isBeforeInSLocAddrSpace(SourceLocation LHS, SourceLocation RHS) const {
1702	return isBeforeInSLocAddrSpace(LHS, RHS: RHS.getOffset());
1703	}
1704
1705	/// Determines the order of a source location and a source location
1706	/// offset in the "source location address space".
1707	///
1708	/// Note that we always consider source locations loaded from
1709	bool isBeforeInSLocAddrSpace(SourceLocation LHS,
1710	SourceLocation::UIntTy RHS) const {
1711	SourceLocation::UIntTy LHSOffset = LHS.getOffset();
1712	bool LHSLoaded = LHSOffset >= CurrentLoadedOffset;
1713	bool RHSLoaded = RHS >= CurrentLoadedOffset;
1714	if (LHSLoaded == RHSLoaded)
1715	return LHSOffset < RHS;
1716
1717	return LHSLoaded;
1718	}
1719
1720	/// Return true if the Point is within Start and End.
1721	bool isPointWithin(SourceLocation Location, SourceLocation Start,
1722	SourceLocation End) const {
1723	return Location == Start || Location == End ||
1724	(isBeforeInTranslationUnit(LHS: Start, RHS: Location) &&
1725	isBeforeInTranslationUnit(LHS: Location, RHS: End));
1726	}
1727
1728	// Iterators over FileInfos.
1729	using fileinfo_iterator =
1730	llvm::DenseMap<FileEntryRef, SrcMgr::ContentCache *>::const_iterator;
1731
1732	fileinfo_iterator fileinfo_begin() const { return FileInfos.begin(); }
1733	fileinfo_iterator fileinfo_end() const { return FileInfos.end(); }
1734	bool hasFileInfo(const FileEntry *File) const {
1735	return FileInfos.find_as(Val: File) != FileInfos.end();
1736	}
1737
1738	/// Print statistics to stderr.
1739	void PrintStats() const;
1740
1741	void dump() const;
1742
1743	// Produce notes describing the current source location address space usage.
1744	void noteSLocAddressSpaceUsage(DiagnosticsEngine &Diag,
1745	std::optional<unsigned> MaxNotes = 32) const;
1746
1747	/// Get the number of local SLocEntries we have.
1748	unsigned local_sloc_entry_size() const { return LocalSLocEntryTable.size(); }
1749
1750	/// Get a local SLocEntry. This is exposed for indexing.
1751	const SrcMgr::SLocEntry &getLocalSLocEntry(unsigned Index) const {
1752	return const_cast<SourceManager *>(this)->getLocalSLocEntry(Index);
1753	}
1754
1755	/// Get a local SLocEntry. This is exposed for indexing.
1756	SrcMgr::SLocEntry &getLocalSLocEntry(unsigned Index) {
1757	assert(Index < LocalSLocEntryTable.size() && "Invalid index");
1758	return LocalSLocEntryTable[Index];
1759	}
1760
1761	/// Get the number of loaded SLocEntries we have.
1762	unsigned loaded_sloc_entry_size() const { return LoadedSLocEntryTable.size();}
1763
1764	/// Get a loaded SLocEntry. This is exposed for indexing.
1765	const SrcMgr::SLocEntry &getLoadedSLocEntry(unsigned Index,
1766	bool *Invalid = nullptr) const {
1767	return const_cast<SourceManager *>(this)->getLoadedSLocEntry(Index,
1768	Invalid);
1769	}
1770
1771	/// Get a loaded SLocEntry. This is exposed for indexing.
1772	SrcMgr::SLocEntry &getLoadedSLocEntry(unsigned Index,
1773	bool *Invalid = nullptr) {
1774	assert(Index < LoadedSLocEntryTable.size() && "Invalid index");
1775	if (SLocEntryLoaded[Index])
1776	return LoadedSLocEntryTable[Index];
1777	return loadSLocEntry(Index, Invalid);
1778	}
1779
1780	const SrcMgr::SLocEntry &getSLocEntry(FileID FID,
1781	bool *Invalid = nullptr) const {
1782	return const_cast<SourceManager *>(this)->getSLocEntry(FID, Invalid);
1783	}
1784
1785	SrcMgr::SLocEntry &getSLocEntry(FileID FID, bool *Invalid = nullptr) {
1786	if (FID.ID == 0 || FID.ID == -1) {
1787	if (Invalid) *Invalid = true;
1788	return LocalSLocEntryTable[0];
1789	}
1790	return getSLocEntryByID(ID: FID.ID, Invalid);
1791	}
1792
1793	SourceLocation::UIntTy getNextLocalOffset() const { return NextLocalOffset; }
1794
1795	void setExternalSLocEntrySource(ExternalSLocEntrySource *Source) {
1796	assert(LoadedSLocEntryTable.empty() &&
1797	"Invalidating existing loaded entries");
1798	ExternalSLocEntries = Source;
1799	}
1800
1801	/// Allocate a number of loaded SLocEntries, which will be actually
1802	/// loaded on demand from the external source.
1803	///
1804	/// NumSLocEntries will be allocated, which occupy a total of TotalSize space
1805	/// in the global source view. The lowest ID and the base offset of the
1806	/// entries will be returned.
1807	std::pair<int, SourceLocation::UIntTy>
1808	AllocateLoadedSLocEntries(unsigned NumSLocEntries,
1809	SourceLocation::UIntTy TotalSize);
1810
1811	/// Returns true if \p Loc came from a PCH/Module.
1812	bool isLoadedSourceLocation(SourceLocation Loc) const {
1813	return isLoadedOffset(SLocOffset: Loc.getOffset());
1814	}
1815
1816	/// Returns true if \p Loc did not come from a PCH/Module.
1817	bool isLocalSourceLocation(SourceLocation Loc) const {
1818	return isLocalOffset(SLocOffset: Loc.getOffset());
1819	}
1820
1821	/// Returns true if \p FID came from a PCH/Module.
1822	bool isLoadedFileID(FileID FID) const {
1823	assert(FID.ID != -1 && "Using FileID sentinel value");
1824	return FID.ID < 0;
1825	}
1826
1827	/// Returns true if \p FID did not come from a PCH/Module.
1828	bool isLocalFileID(FileID FID) const {
1829	return !isLoadedFileID(FID);
1830	}
1831
1832	/// Gets the location of the immediate macro caller, one level up the stack
1833	/// toward the initial macro typed into the source.
1834	SourceLocation getImmediateMacroCallerLoc(SourceLocation Loc) const {
1835	if (!Loc.isMacroID()) return Loc;
1836
1837	// When we have the location of (part of) an expanded parameter, its
1838	// spelling location points to the argument as expanded in the macro call,
1839	// and therefore is used to locate the macro caller.
1840	if (isMacroArgExpansion(Loc))
1841	return getImmediateSpellingLoc(Loc);
1842
1843	// Otherwise, the caller of the macro is located where this macro is
1844	// expanded (while the spelling is part of the macro definition).
1845	return getImmediateExpansionRange(Loc).getBegin();
1846	}
1847
1848	/// \return Location of the top-level macro caller.
1849	SourceLocation getTopMacroCallerLoc(SourceLocation Loc) const;
1850
1851	private:
1852	friend class ASTReader;
1853	friend class ASTWriter;
1854
1855	llvm::MemoryBufferRef getFakeBufferForRecovery() const;
1856	SrcMgr::ContentCache &getFakeContentCacheForRecovery() const;
1857
1858	const SrcMgr::SLocEntry &loadSLocEntry(unsigned Index, bool *Invalid) const;
1859	SrcMgr::SLocEntry &loadSLocEntry(unsigned Index, bool *Invalid);
1860
1861	const SrcMgr::SLocEntry *getSLocEntryOrNull(FileID FID) const {
1862	return const_cast<SourceManager *>(this)->getSLocEntryOrNull(FID);
1863	}
1864
1865	SrcMgr::SLocEntry *getSLocEntryOrNull(FileID FID) {
1866	bool Invalid = false;
1867	SrcMgr::SLocEntry &Entry = getSLocEntry(FID, Invalid: &Invalid);
1868	return Invalid ? nullptr : &Entry;
1869	}
1870
1871	const SrcMgr::SLocEntry *getSLocEntryForFile(FileID FID) const {
1872	return const_cast<SourceManager *>(this)->getSLocEntryForFile(FID);
1873	}
1874
1875	SrcMgr::SLocEntry *getSLocEntryForFile(FileID FID) {
1876	if (auto *Entry = getSLocEntryOrNull(FID))
1877	if (Entry->isFile())
1878	return Entry;
1879	return nullptr;
1880	}
1881
1882	/// Get the entry with the given unwrapped FileID.
1883	/// Invalid will not be modified for Local IDs.
1884	const SrcMgr::SLocEntry &getSLocEntryByID(int ID,
1885	bool *Invalid = nullptr) const {
1886	return const_cast<SourceManager *>(this)->getSLocEntryByID(ID, Invalid);
1887	}
1888
1889	SrcMgr::SLocEntry &getSLocEntryByID(int ID, bool *Invalid = nullptr) {
1890	assert(ID != -1 && "Using FileID sentinel value");
1891	if (ID < 0)
1892	return getLoadedSLocEntryByID(ID, Invalid);
1893	return getLocalSLocEntry(Index: static_cast<unsigned>(ID));
1894	}
1895
1896	const SrcMgr::SLocEntry &
1897	getLoadedSLocEntryByID(int ID, bool *Invalid = nullptr) const {
1898	return const_cast<SourceManager *>(this)->getLoadedSLocEntryByID(ID,
1899	Invalid);
1900	}
1901
1902	SrcMgr::SLocEntry &getLoadedSLocEntryByID(int ID, bool *Invalid = nullptr) {
1903	return getLoadedSLocEntry(Index: static_cast<unsigned>(-ID - 2), Invalid);
1904	}
1905
1906	FileID getFileID(SourceLocation::UIntTy SLocOffset) const {
1907	// If our one-entry cache covers this offset, just return it.
1908	if (SLocOffset >= LastLookupStartOffset && SLocOffset < LastLookupEndOffset)
1909	return LastFileIDLookup;
1910	return getFileIDSlow(SLocOffset);
1911	}
1912
1913	bool isLocalOffset(SourceLocation::UIntTy SLocOffset) const {
1914	return SLocOffset < CurrentLoadedOffset;
1915	}
1916
1917	bool isLoadedOffset(SourceLocation::UIntTy SLocOffset) const {
1918	return SLocOffset >= CurrentLoadedOffset;
1919	}
1920
1921	/// Implements the common elements of storing an expansion info struct into
1922	/// the SLocEntry table and producing a source location that refers to it.
1923	SourceLocation
1924	createExpansionLocImpl(const SrcMgr::ExpansionInfo &Expansion,
1925	unsigned Length, int LoadedID = 0,
1926	SourceLocation::UIntTy LoadedOffset = 0);
1927
1928	/// Return true if the specified FileID contains the
1929	/// specified SourceLocation offset. This is a very hot method.
1930	inline bool isOffsetInFileID(FileID FID,
1931	SourceLocation::UIntTy SLocOffset) const {
1932	const SrcMgr::SLocEntry &Entry = getSLocEntry(FID);
1933	// If the entry is after the offset, it can't contain it.
1934	if (SLocOffset < Entry.getOffset()) return false;
1935
1936	// If this is the very last entry then it does.
1937	if (FID.ID == -2)
1938	return true;
1939
1940	// If it is the last local entry, then it does if the location is local.
1941	if (FID.ID+1 == static_cast<int>(LocalSLocEntryTable.size()))
1942	return SLocOffset < NextLocalOffset;
1943
1944	// Otherwise, the entry after it has to not include it. This works for both
1945	// local and loaded entries.
1946	return SLocOffset < getSLocEntryByID(ID: FID.ID+1).getOffset();
1947	}
1948
1949	/// Returns the previous in-order FileID or an invalid FileID if there
1950	/// is no previous one.
1951	FileID getPreviousFileID(FileID FID) const;
1952
1953	/// Returns the next in-order FileID or an invalid FileID if there is
1954	/// no next one.
1955	FileID getNextFileID(FileID FID) const;
1956
1957	/// Create a new fileID for the specified ContentCache and
1958	/// include position.
1959	///
1960	/// This works regardless of whether the ContentCache corresponds to a
1961	/// file or some other input source.
1962	FileID createFileIDImpl(SrcMgr::ContentCache &File, StringRef Filename,
1963	SourceLocation IncludePos,
1964	SrcMgr::CharacteristicKind DirCharacter, int LoadedID,
1965	SourceLocation::UIntTy LoadedOffset);
1966
1967	SrcMgr::ContentCache &getOrCreateContentCache(FileEntryRef SourceFile,
1968	bool isSystemFile = false);
1969
1970	/// Create a new ContentCache for the specified memory buffer.
1971	SrcMgr::ContentCache &
1972	createMemBufferContentCache(std::unique_ptr<llvm::MemoryBuffer> Buf);
1973
1974	FileID getFileIDSlow(SourceLocation::UIntTy SLocOffset) const;
1975	FileID getFileIDLocal(SourceLocation::UIntTy SLocOffset) const;
1976	FileID getFileIDLoaded(SourceLocation::UIntTy SLocOffset) const;
1977
1978	SourceLocation getExpansionLocSlowCase(SourceLocation Loc) const;
1979	SourceLocation getSpellingLocSlowCase(SourceLocation Loc) const;
1980	SourceLocation getFileLocSlowCase(SourceLocation Loc) const;
1981
1982	FileIDAndOffset
1983	getDecomposedExpansionLocSlowCase(const SrcMgr::SLocEntry *E) const;
1984	FileIDAndOffset getDecomposedSpellingLocSlowCase(const SrcMgr::SLocEntry *E,
1985	unsigned Offset) const;
1986	void computeMacroArgsCache(MacroArgsMap &MacroArgsCache, FileID FID) const;
1987	void associateFileChunkWithMacroArgExp(MacroArgsMap &MacroArgsCache,
1988	FileID FID,
1989	SourceLocation SpellLoc,
1990	SourceLocation ExpansionLoc,
1991	unsigned ExpansionLength) const;
1992	void updateSlocUsageStats() const;
1993	};
1994
1995	/// Comparison function object.
1996	template<typename T>
1997	class BeforeThanCompare;
1998
1999	/// Compare two source locations.
2000	template<>
2001	class BeforeThanCompare<SourceLocation> {
2002	SourceManager &SM;
2003
2004	public:
2005	explicit BeforeThanCompare(SourceManager &SM) : SM(SM) {}
2006
2007	bool operator()(SourceLocation LHS, SourceLocation RHS) const {
2008	return SM.isBeforeInTranslationUnit(LHS, RHS);
2009	}
2010	};
2011
2012	/// Compare two non-overlapping source ranges.
2013	template<>
2014	class BeforeThanCompare<SourceRange> {
2015	SourceManager &SM;
2016
2017	public:
2018	explicit BeforeThanCompare(SourceManager &SM) : SM(SM) {}
2019
2020	bool operator()(SourceRange LHS, SourceRange RHS) const {
2021	return SM.isBeforeInTranslationUnit(LHS: LHS.getBegin(), RHS: RHS.getBegin());
2022	}
2023	};
2024
2025	/// SourceManager and necessary dependencies (e.g. VFS, FileManager) for a
2026	/// single in-memorty file.
2027	class SourceManagerForFile {
2028	public:
2029	/// Creates SourceManager and necessary dependencies (e.g. VFS, FileManager).
2030	/// The main file in the SourceManager will be \p FileName with \p Content.
2031	SourceManagerForFile(StringRef FileName, StringRef Content);
2032
2033	SourceManager &get() {
2034	assert(SourceMgr);
2035	return *SourceMgr;
2036	}
2037
2038	private:
2039	// The order of these fields are important - they should be in the same order
2040	// as they are created in `createSourceManagerForFile` so that they can be
2041	// deleted in the reverse order as they are created.
2042	std::unique_ptr<FileManager> FileMgr;
2043	std::unique_ptr<DiagnosticOptions> DiagOpts;
2044	std::unique_ptr<DiagnosticsEngine> Diagnostics;
2045	std::unique_ptr<SourceManager> SourceMgr;
2046	};
2047
2048	} // namespace clang
2049
2050	#endif // LLVM_CLANG_BASIC_SOURCEMANAGER_H
2051