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	assert(isFile() && "Not a file SLocEntry!");
501	return File;
502	}
503
504	const ExpansionInfo &getExpansion() const {
505	assert(isExpansion() && "Not a macro expansion SLocEntry!");
506	return Expansion;
507	}
508
509	/// Creates an incomplete SLocEntry that is only able to report its offset.
510	static SLocEntry getOffsetOnly(SourceLocation::UIntTy Offset) {
511	assert(!(Offset & (1ULL << OffsetBits)) && "Offset is too large");
512	SLocEntry E;
513	E.Offset = Offset;
514	return E;
515	}
516
517	static SLocEntry get(SourceLocation::UIntTy Offset, const FileInfo &FI) {
518	assert(!(Offset & (1ULL << OffsetBits)) && "Offset is too large");
519	SLocEntry E;
520	E.Offset = Offset;
521	E.IsExpansion = false;
522	E.File = FI;
523	return E;
524	}
525
526	static SLocEntry get(SourceLocation::UIntTy Offset,
527	const ExpansionInfo &Expansion) {
528	assert(!(Offset & (1ULL << OffsetBits)) && "Offset is too large");
529	SLocEntry E;
530	E.Offset = Offset;
531	E.IsExpansion = true;
532	new (&E.Expansion) ExpansionInfo(Expansion);
533	return E;
534	}
535	};
536
537	} // namespace SrcMgr
538
539	/// External source of source location entries.
540	class ExternalSLocEntrySource {
541	public:
542	virtual ~ExternalSLocEntrySource();
543
544	/// Read the source location entry with index ID, which will always be
545	/// less than -1.
546	///
547	/// \returns true if an error occurred that prevented the source-location
548	/// entry from being loaded.
549	virtual bool ReadSLocEntry(int ID) = 0;
550
551	/// Get the index ID for the loaded SourceLocation offset.
552	///
553	/// \returns Invalid index ID (0) if an error occurred that prevented the
554	/// SLocEntry from being loaded.
555	virtual int getSLocEntryID(SourceLocation::UIntTy SLocOffset) = 0;
556
557	/// Retrieve the module import location and name for the given ID, if
558	/// in fact it was loaded from a module (rather than, say, a precompiled
559	/// header).
560	virtual std::pair<SourceLocation, StringRef> getModuleImportLoc(int ID) = 0;
561	};
562
563	/// Holds the cache used by isBeforeInTranslationUnit.
564	///
565	/// The cache structure is complex enough to be worth breaking out of
566	/// SourceManager.
567	class InBeforeInTUCacheEntry {
568	/// The FileID's of the cached query.
569	///
570	/// If these match up with a subsequent query, the result can be reused.
571	FileID LQueryFID, RQueryFID;
572
573	/// The relative order of FileIDs that the CommonFID *immediately* includes.
574	///
575	/// This is used to compare macro expansion locations.
576	bool LChildBeforeRChild;
577
578	/// The file found in common between the two \#include traces, i.e.,
579	/// the nearest common ancestor of the \#include tree.
580	FileID CommonFID;
581
582	/// The offset of the previous query in CommonFID.
583	///
584	/// Usually, this represents the location of the \#include for QueryFID, but
585	/// if LQueryFID is a parent of RQueryFID (or vice versa) then these can be a
586	/// random token in the parent.
587	unsigned LCommonOffset, RCommonOffset;
588
589	public:
590	InBeforeInTUCacheEntry() = default;
591	InBeforeInTUCacheEntry(FileID L, FileID R) : LQueryFID(L), RQueryFID(R) {
592	assert(L != R);
593	}
594
595	/// Return true if the currently cached values match up with
596	/// the specified LHS/RHS query.
597	///
598	/// If not, we can't use the cache.
599	bool isCacheValid() const {
600	return CommonFID.isValid();
601	}
602
603	/// If the cache is valid, compute the result given the
604	/// specified offsets in the LHS/RHS FileID's.
605	bool getCachedResult(unsigned LOffset, unsigned ROffset) const {
606	// If one of the query files is the common file, use the offset. Otherwise,
607	// use the #include loc in the common file.
608	if (LQueryFID != CommonFID) LOffset = LCommonOffset;
609	if (RQueryFID != CommonFID) ROffset = RCommonOffset;
610
611	// It is common for multiple macro expansions to be "included" from the same
612	// location (expansion location), in which case use the order of the FileIDs
613	// to determine which came first. This will also take care the case where
614	// one of the locations points at the inclusion/expansion point of the other
615	// in which case its FileID will come before the other.
616	if (LOffset == ROffset)
617	return LChildBeforeRChild;
618
619	return LOffset < ROffset;
620	}
621
622	/// Set up a new query.
623	/// If it matches the old query, we can keep the cached answer.
624	void setQueryFIDs(FileID LHS, FileID RHS) {
625	assert(LHS != RHS);
626	if (LQueryFID != LHS || RQueryFID != RHS) {
627	LQueryFID = LHS;
628	RQueryFID = RHS;
629	CommonFID = FileID();
630	}
631	}
632
633	void setCommonLoc(FileID commonFID, unsigned lCommonOffset,
634	unsigned rCommonOffset, bool LParentBeforeRParent) {
635	CommonFID = commonFID;
636	LCommonOffset = lCommonOffset;
637	RCommonOffset = rCommonOffset;
638	LChildBeforeRChild = LParentBeforeRParent;
639	}
640	};
641
642	/// The stack used when building modules on demand, which is used
643	/// to provide a link between the source managers of the different compiler
644	/// instances.
645	using ModuleBuildStack = ArrayRef<std::pair<std::string, FullSourceLoc>>;
646
647	/// This class handles loading and caching of source files into memory.
648	///
649	/// This object owns the MemoryBuffer objects for all of the loaded
650	/// files and assigns unique FileID's for each unique \#include chain.
651	///
652	/// The SourceManager can be queried for information about SourceLocation
653	/// objects, turning them into either spelling or expansion locations. Spelling
654	/// locations represent where the bytes corresponding to a token came from and
655	/// expansion locations represent where the location is in the user's view. In
656	/// the case of a macro expansion, for example, the spelling location indicates
657	/// where the expanded token came from and the expansion location specifies
658	/// where it was expanded.
659	class SourceManager : public RefCountedBase<SourceManager> {
660	/// DiagnosticsEngine object.
661	DiagnosticsEngine &Diag;
662
663	FileManager &FileMgr;
664
665	mutable llvm::BumpPtrAllocator ContentCacheAlloc;
666
667	/// Memoized information about all of the files tracked by this
668	/// SourceManager.
669	///
670	/// This map allows us to merge ContentCache entries based
671	/// on their FileEntry*. All ContentCache objects will thus have unique,
672	/// non-null, FileEntry pointers.
673	llvm::DenseMap<FileEntryRef, SrcMgr::ContentCache*> FileInfos;
674
675	/// True if the ContentCache for files that are overridden by other
676	/// files, should report the original file name. Defaults to true.
677	bool OverridenFilesKeepOriginalName = true;
678
679	/// True if non-system source files should be treated as volatile
680	/// (likely to change while trying to use them). Defaults to false.
681	bool UserFilesAreVolatile;
682
683	/// True if all files read during this compilation should be treated
684	/// as transient (may not be present in later compilations using a module
685	/// file created from this compilation). Defaults to false.
686	bool FilesAreTransient = false;
687
688	struct OverriddenFilesInfoTy {
689	/// Files that have been overridden with the contents from another
690	/// file.
691	llvm::DenseMap<const FileEntry *, FileEntryRef> OverriddenFiles;
692
693	/// Files that were overridden with a memory buffer.
694	llvm::DenseSet<const FileEntry *> OverriddenFilesWithBuffer;
695	};
696
697	/// Lazily create the object keeping overridden files info, since
698	/// it is uncommonly used.
699	std::unique_ptr<OverriddenFilesInfoTy> OverriddenFilesInfo;
700
701	OverriddenFilesInfoTy &getOverriddenFilesInfo() {
702	if (!OverriddenFilesInfo)
703	OverriddenFilesInfo.reset(p: new OverriddenFilesInfoTy);
704	return *OverriddenFilesInfo;
705	}
706
707	/// Information about various memory buffers that we have read in.
708	///
709	/// All FileEntry* within the stored ContentCache objects are NULL,
710	/// as they do not refer to a file.
711	std::vector<SrcMgr::ContentCache*> MemBufferInfos;
712
713	/// The table of SLocEntries that are local to this module.
714	///
715	/// Positive FileIDs are indexes into this table. Entry 0 indicates an invalid
716	/// expansion.
717	SmallVector<SrcMgr::SLocEntry, 0> LocalSLocEntryTable;
718
719	/// The table of SLocEntries that are loaded from other modules.
720	///
721	/// Negative FileIDs are indexes into this table. To get from ID to an index,
722	/// use (-ID - 2).
723	llvm::PagedVector<SrcMgr::SLocEntry> LoadedSLocEntryTable;
724
725	/// For each allocation in LoadedSLocEntryTable, we keep the first FileID.
726	/// We assume exactly one allocation per AST file, and use that to determine
727	/// whether two FileIDs come from the same AST file.
728	SmallVector<FileID, 0> LoadedSLocEntryAllocBegin;
729
730	/// The starting offset of the next local SLocEntry.
731	///
732	/// This is LocalSLocEntryTable.back().Offset + the size of that entry.
733	SourceLocation::UIntTy NextLocalOffset;
734
735	/// The starting offset of the latest batch of loaded SLocEntries.
736	///
737	/// This is LoadedSLocEntryTable.back().Offset, except that that entry might
738	/// not have been loaded, so that value would be unknown.
739	SourceLocation::UIntTy CurrentLoadedOffset;
740
741	/// The highest possible offset is 2^31-1 (2^63-1 for 64-bit source
742	/// locations), so CurrentLoadedOffset starts at 2^31 (2^63 resp.).
743	static const SourceLocation::UIntTy MaxLoadedOffset =
744	1ULL << (8 * sizeof(SourceLocation::UIntTy) - 1);
745
746	/// A bitmap that indicates whether the entries of LoadedSLocEntryTable
747	/// have already been loaded from the external source.
748	///
749	/// Same indexing as LoadedSLocEntryTable.
750	llvm::BitVector SLocEntryLoaded;
751
752	/// A bitmap that indicates whether the entries of LoadedSLocEntryTable
753	/// have already had their offset loaded from the external source.
754	///
755	/// Superset of SLocEntryLoaded. Same indexing as SLocEntryLoaded.
756	llvm::BitVector SLocEntryOffsetLoaded;
757
758	/// An external source for source location entries.
759	ExternalSLocEntrySource *ExternalSLocEntries = nullptr;
760
761	/// A one-entry cache to speed up getFileID.
762	///
763	/// LastFileIDLookup records the last FileID looked up or created, because it
764	/// is very common to look up many tokens from the same file.
765	mutable FileID LastFileIDLookup;
766
767	/// Holds information for \#line directives.
768	///
769	/// This is referenced by indices from SLocEntryTable.
770	std::unique_ptr<LineTableInfo> LineTable;
771
772	/// These ivars serve as a cache used in the getLineNumber
773	/// method which is used to speedup getLineNumber calls to nearby locations.
774	mutable FileID LastLineNoFileIDQuery;
775	mutable const SrcMgr::ContentCache *LastLineNoContentCache;
776	mutable unsigned LastLineNoFilePos;
777	mutable unsigned LastLineNoResult;
778
779	/// The file ID for the main source file of the translation unit.
780	FileID MainFileID;
781
782	/// The file ID for the precompiled preamble there is one.
783	FileID PreambleFileID;
784
785	// Statistics for -print-stats.
786	mutable unsigned NumLinearScans = 0;
787	mutable unsigned NumBinaryProbes = 0;
788
789	/// Associates a FileID with its "included/expanded in" decomposed
790	/// location.
791	///
792	/// Used to cache results from and speed-up \c getDecomposedIncludedLoc
793	/// function.
794	mutable llvm::DenseMap<FileID, std::pair<FileID, unsigned>> IncludedLocMap;
795
796	/// The key value into the IsBeforeInTUCache table.
797	using IsBeforeInTUCacheKey = std::pair<FileID, FileID>;
798
799	/// The IsBeforeInTranslationUnitCache is a mapping from FileID pairs
800	/// to cache results.
801	using InBeforeInTUCache =
802	llvm::DenseMap<IsBeforeInTUCacheKey, InBeforeInTUCacheEntry>;
803
804	/// Cache results for the isBeforeInTranslationUnit method.
805	mutable InBeforeInTUCache IBTUCache;
806	mutable InBeforeInTUCacheEntry IBTUCacheOverflow;
807
808	/// Return the cache entry for comparing the given file IDs
809	/// for isBeforeInTranslationUnit.
810	InBeforeInTUCacheEntry &getInBeforeInTUCache(FileID LFID, FileID RFID) const;
811
812	// Cache for the "fake" buffer used for error-recovery purposes.
813	mutable std::unique_ptr<llvm::MemoryBuffer> FakeBufferForRecovery;
814
815	mutable std::unique_ptr<SrcMgr::ContentCache> FakeContentCacheForRecovery;
816
817	mutable std::unique_ptr<SrcMgr::SLocEntry> FakeSLocEntryForRecovery;
818
819	/// Lazily computed map of macro argument chunks to their expanded
820	/// source location.
821	using MacroArgsMap = std::map<unsigned, SourceLocation>;
822
823	mutable llvm::DenseMap<FileID, std::unique_ptr<MacroArgsMap>>
824	MacroArgsCacheMap;
825
826	/// The stack of modules being built, which is used to detect
827	/// cycles in the module dependency graph as modules are being built, as
828	/// well as to describe why we're rebuilding a particular module.
829	///
830	/// There is no way to set this value from the command line. If we ever need
831	/// to do so (e.g., if on-demand module construction moves out-of-process),
832	/// we can add a cc1-level option to do so.
833	SmallVector<std::pair<std::string, FullSourceLoc>, 2> StoredModuleBuildStack;
834
835	public:
836	SourceManager(DiagnosticsEngine &Diag, FileManager &FileMgr,
837	bool UserFilesAreVolatile = false);
838	explicit SourceManager(const SourceManager &) = delete;
839	SourceManager &operator=(const SourceManager &) = delete;
840	~SourceManager();
841
842	void clearIDTables();
843
844	/// Initialize this source manager suitably to replay the compilation
845	/// described by \p Old. Requires that \p Old outlive \p *this.
846	void initializeForReplay(const SourceManager &Old);
847
848	DiagnosticsEngine &getDiagnostics() const { return Diag; }
849
850	FileManager &getFileManager() const { return FileMgr; }
851
852	/// Set true if the SourceManager should report the original file name
853	/// for contents of files that were overridden by other files. Defaults to
854	/// true.
855	void setOverridenFilesKeepOriginalName(bool value) {
856	OverridenFilesKeepOriginalName = value;
857	}
858
859	/// True if non-system source files should be treated as volatile
860	/// (likely to change while trying to use them).
861	bool userFilesAreVolatile() const { return UserFilesAreVolatile; }
862
863	/// Retrieve the module build stack.
864	ModuleBuildStack getModuleBuildStack() const {
865	return StoredModuleBuildStack;
866	}
867
868	/// Set the module build stack.
869	void setModuleBuildStack(ModuleBuildStack stack) {
870	StoredModuleBuildStack.clear();
871	StoredModuleBuildStack.append(in_start: stack.begin(), in_end: stack.end());
872	}
873
874	/// Push an entry to the module build stack.
875	void pushModuleBuildStack(StringRef moduleName, FullSourceLoc importLoc) {
876	StoredModuleBuildStack.push_back(Elt: std::make_pair(x: moduleName.str(),y&: importLoc));
877	}
878
879	//===--------------------------------------------------------------------===//
880	// MainFileID creation and querying methods.
881	//===--------------------------------------------------------------------===//
882
883	/// Returns the FileID of the main source file.
884	FileID getMainFileID() const { return MainFileID; }
885
886	/// Set the file ID for the main source file.
887	void setMainFileID(FileID FID) {
888	MainFileID = FID;
889	}
890
891	/// Returns true when the given FileEntry corresponds to the main file.
892	///
893	/// The main file should be set prior to calling this function.
894	bool isMainFile(const FileEntry &SourceFile);
895
896	/// Set the file ID for the precompiled preamble.
897	void setPreambleFileID(FileID Preamble) {
898	assert(PreambleFileID.isInvalid() && "PreambleFileID already set!");
899	PreambleFileID = Preamble;
900	}
901
902	/// Get the file ID for the precompiled preamble if there is one.
903	FileID getPreambleFileID() const { return PreambleFileID; }
904
905	//===--------------------------------------------------------------------===//
906	// Methods to create new FileID's and macro expansions.
907	//===--------------------------------------------------------------------===//
908
909	/// Create a new FileID that represents the specified file
910	/// being \#included from the specified IncludePosition.
911	FileID createFileID(FileEntryRef SourceFile, SourceLocation IncludePos,
912	SrcMgr::CharacteristicKind FileCharacter,
913	int LoadedID = 0,
914	SourceLocation::UIntTy LoadedOffset = 0);
915
916	/// Create a new FileID that represents the specified memory buffer.
917	///
918	/// This does no caching of the buffer and takes ownership of the
919	/// MemoryBuffer, so only pass a MemoryBuffer to this once.
920	FileID createFileID(std::unique_ptr<llvm::MemoryBuffer> Buffer,
921	SrcMgr::CharacteristicKind FileCharacter = SrcMgr::C_User,
922	int LoadedID = 0, SourceLocation::UIntTy LoadedOffset = 0,
923	SourceLocation IncludeLoc = SourceLocation());
924
925	/// Create a new FileID that represents the specified memory buffer.
926	///
927	/// This does not take ownership of the MemoryBuffer. The memory buffer must
928	/// outlive the SourceManager.
929	FileID createFileID(const llvm::MemoryBufferRef &Buffer,
930	SrcMgr::CharacteristicKind FileCharacter = SrcMgr::C_User,
931	int LoadedID = 0, SourceLocation::UIntTy LoadedOffset = 0,
932	SourceLocation IncludeLoc = SourceLocation());
933
934	/// Get the FileID for \p SourceFile if it exists. Otherwise, create a
935	/// new FileID for the \p SourceFile.
936	FileID getOrCreateFileID(FileEntryRef SourceFile,
937	SrcMgr::CharacteristicKind FileCharacter);
938
939	/// Creates an expansion SLocEntry for the substitution of an argument into a
940	/// function-like macro's body. Returns the start of the expansion.
941	///
942	/// The macro argument was written at \p SpellingLoc with length \p Length.
943	/// \p ExpansionLoc is the parameter name in the (expanded) macro body.
944	SourceLocation createMacroArgExpansionLoc(SourceLocation SpellingLoc,
945	SourceLocation ExpansionLoc,
946	unsigned Length);
947
948	/// Creates an expansion SLocEntry for a macro use. Returns its start.
949	///
950	/// The macro body begins at \p SpellingLoc with length \p Length.
951	/// The macro use spans [ExpansionLocStart, ExpansionLocEnd].
952	SourceLocation createExpansionLoc(SourceLocation SpellingLoc,
953	SourceLocation ExpansionLocStart,
954	SourceLocation ExpansionLocEnd,
955	unsigned Length,
956	bool ExpansionIsTokenRange = true,
957	int LoadedID = 0,
958	SourceLocation::UIntTy LoadedOffset = 0);
959
960	/// Return a new SourceLocation that encodes that the token starting
961	/// at \p TokenStart ends prematurely at \p TokenEnd.
962	SourceLocation createTokenSplitLoc(SourceLocation SpellingLoc,
963	SourceLocation TokenStart,
964	SourceLocation TokenEnd);
965
966	/// Retrieve the memory buffer associated with the given file.
967	///
968	/// Returns std::nullopt if the buffer is not valid.
969	std::optional<llvm::MemoryBufferRef>
970	getMemoryBufferForFileOrNone(FileEntryRef File);
971
972	/// Retrieve the memory buffer associated with the given file.
973	///
974	/// Returns a fake buffer if there isn't a real one.
975	llvm::MemoryBufferRef getMemoryBufferForFileOrFake(FileEntryRef File) {
976	if (auto B = getMemoryBufferForFileOrNone(File))
977	return *B;
978	return getFakeBufferForRecovery();
979	}
980
981	/// Override the contents of the given source file by providing an
982	/// already-allocated buffer.
983	///
984	/// \param SourceFile the source file whose contents will be overridden.
985	///
986	/// \param Buffer the memory buffer whose contents will be used as the
987	/// data in the given source file.
988	void overrideFileContents(FileEntryRef SourceFile,
989	const llvm::MemoryBufferRef &Buffer) {
990	overrideFileContents(SourceFile, Buffer: llvm::MemoryBuffer::getMemBuffer(Ref: Buffer));
991	}
992
993	/// Override the contents of the given source file by providing an
994	/// already-allocated buffer.
995	///
996	/// \param SourceFile the source file whose contents will be overridden.
997	///
998	/// \param Buffer the memory buffer whose contents will be used as the
999	/// data in the given source file.
1000	void overrideFileContents(FileEntryRef SourceFile,
1001	std::unique_ptr<llvm::MemoryBuffer> Buffer);
1002
1003	/// Override the given source file with another one.
1004	///
1005	/// \param SourceFile the source file which will be overridden.
1006	///
1007	/// \param NewFile the file whose contents will be used as the
1008	/// data instead of the contents of the given source file.
1009	void overrideFileContents(const FileEntry *SourceFile, FileEntryRef NewFile);
1010
1011	/// Returns true if the file contents have been overridden.
1012	bool isFileOverridden(const FileEntry *File) const {
1013	if (OverriddenFilesInfo) {
1014	if (OverriddenFilesInfo->OverriddenFilesWithBuffer.count(V: File))
1015	return true;
1016	if (OverriddenFilesInfo->OverriddenFiles.contains(Val: File))
1017	return true;
1018	}
1019	return false;
1020	}
1021
1022	/// Bypass the overridden contents of a file. This creates a new FileEntry
1023	/// and initializes the content cache for it. Returns std::nullopt if there
1024	/// is no such file in the filesystem.
1025	///
1026	/// This should be called before parsing has begun.
1027	OptionalFileEntryRef bypassFileContentsOverride(FileEntryRef File);
1028
1029	/// Specify that a file is transient.
1030	void setFileIsTransient(FileEntryRef SourceFile);
1031
1032	/// Specify that all files that are read during this compilation are
1033	/// transient.
1034	void setAllFilesAreTransient(bool Transient) {
1035	FilesAreTransient = Transient;
1036	}
1037
1038	//===--------------------------------------------------------------------===//
1039	// FileID manipulation methods.
1040	//===--------------------------------------------------------------------===//
1041
1042	/// Return the buffer for the specified FileID.
1043	///
1044	/// If there is an error opening this buffer the first time, return
1045	/// std::nullopt.
1046	std::optional<llvm::MemoryBufferRef>
1047	getBufferOrNone(FileID FID, SourceLocation Loc = SourceLocation()) const {
1048	if (auto *Entry = getSLocEntryForFile(FID))
1049	return Entry->getFile().getContentCache().getBufferOrNone(
1050	Diag, FM&: getFileManager(), Loc);
1051	return std::nullopt;
1052	}
1053
1054	/// Return the buffer for the specified FileID.
1055	///
1056	/// If there is an error opening this buffer the first time, this
1057	/// manufactures a temporary buffer and returns it.
1058	llvm::MemoryBufferRef
1059	getBufferOrFake(FileID FID, SourceLocation Loc = SourceLocation()) const {
1060	if (auto B = getBufferOrNone(FID, Loc))
1061	return *B;
1062	return getFakeBufferForRecovery();
1063	}
1064
1065	/// Returns the FileEntry record for the provided FileID.
1066	const FileEntry *getFileEntryForID(FileID FID) const {
1067	if (auto FE = getFileEntryRefForID(FID))
1068	return *FE;
1069	return nullptr;
1070	}
1071
1072	/// Returns the FileEntryRef for the provided FileID.
1073	OptionalFileEntryRef getFileEntryRefForID(FileID FID) const {
1074	if (auto *Entry = getSLocEntryForFile(FID))
1075	return Entry->getFile().getContentCache().OrigEntry;
1076	return std::nullopt;
1077	}
1078
1079	/// Returns the filename for the provided FileID, unless it's a built-in
1080	/// buffer that's not represented by a filename.
1081	///
1082	/// Returns std::nullopt for non-files and built-in files.
1083	std::optional<StringRef> getNonBuiltinFilenameForID(FileID FID) const;
1084
1085	/// Returns the FileEntry record for the provided SLocEntry.
1086	const FileEntry *
1087	getFileEntryForSLocEntry(const SrcMgr::SLocEntry &SLocEntry) const {
1088	if (auto FE = SLocEntry.getFile().getContentCache().OrigEntry)
1089	return *FE;
1090	return nullptr;
1091	}
1092
1093	/// Return a StringRef to the source buffer data for the
1094	/// specified FileID.
1095	///
1096	/// \param FID The file ID whose contents will be returned.
1097	/// \param Invalid If non-NULL, will be set true if an error occurred.
1098	StringRef getBufferData(FileID FID, bool *Invalid = nullptr) const;
1099
1100	/// Return a StringRef to the source buffer data for the
1101	/// specified FileID, returning std::nullopt if invalid.
1102	///
1103	/// \param FID The file ID whose contents will be returned.
1104	std::optional<StringRef> getBufferDataOrNone(FileID FID) const;
1105
1106	/// Return a StringRef to the source buffer data for the
1107	/// specified FileID, returning std::nullopt if it's not yet loaded.
1108	///
1109	/// \param FID The file ID whose contents will be returned.
1110	std::optional<StringRef> getBufferDataIfLoaded(FileID FID) const;
1111
1112	/// Get the number of FileIDs (files and macros) that were created
1113	/// during preprocessing of \p FID, including it.
1114	unsigned getNumCreatedFIDsForFileID(FileID FID) const {
1115	if (auto *Entry = getSLocEntryForFile(FID))
1116	return Entry->getFile().NumCreatedFIDs;
1117	return 0;
1118	}
1119
1120	/// Set the number of FileIDs (files and macros) that were created
1121	/// during preprocessing of \p FID, including it.
1122	void setNumCreatedFIDsForFileID(FileID FID, unsigned NumFIDs,
1123	bool Force = false) const {
1124	auto *Entry = getSLocEntryForFile(FID);
1125	if (!Entry)
1126	return;
1127	assert((Force || Entry->getFile().NumCreatedFIDs == 0) && "Already set!");
1128	const_cast<SrcMgr::FileInfo &>(Entry->getFile()).NumCreatedFIDs = NumFIDs;
1129	}
1130
1131	//===--------------------------------------------------------------------===//
1132	// SourceLocation manipulation methods.
1133	//===--------------------------------------------------------------------===//
1134
1135	/// Return the FileID for a SourceLocation.
1136	///
1137	/// This is a very hot method that is used for all SourceManager queries
1138	/// that start with a SourceLocation object. It is responsible for finding
1139	/// the entry in SLocEntryTable which contains the specified location.
1140	///
1141	FileID getFileID(SourceLocation SpellingLoc) const {
1142	return getFileID(SLocOffset: SpellingLoc.getOffset());
1143	}
1144
1145	/// Return the filename of the file containing a SourceLocation.
1146	StringRef getFilename(SourceLocation SpellingLoc) const;
1147
1148	/// Return the source location corresponding to the first byte of
1149	/// the specified file.
1150	SourceLocation getLocForStartOfFile(FileID FID) const {
1151	if (auto *Entry = getSLocEntryForFile(FID))
1152	return SourceLocation::getFileLoc(ID: Entry->getOffset());
1153	return SourceLocation();
1154	}
1155
1156	/// Return the source location corresponding to the last byte of the
1157	/// specified file.
1158	SourceLocation getLocForEndOfFile(FileID FID) const {
1159	if (auto *Entry = getSLocEntryForFile(FID))
1160	return SourceLocation::getFileLoc(ID: Entry->getOffset() +
1161	getFileIDSize(FID));
1162	return SourceLocation();
1163	}
1164
1165	/// Returns the include location if \p FID is a \#include'd file
1166	/// otherwise it returns an invalid location.
1167	SourceLocation getIncludeLoc(FileID FID) const {
1168	if (auto *Entry = getSLocEntryForFile(FID))
1169	return Entry->getFile().getIncludeLoc();
1170	return SourceLocation();
1171	}
1172
1173	// Returns the import location if the given source location is
1174	// located within a module, or an invalid location if the source location
1175	// is within the current translation unit.
1176	std::pair<SourceLocation, StringRef>
1177	getModuleImportLoc(SourceLocation Loc) const {
1178	FileID FID = getFileID(SpellingLoc: Loc);
1179
1180	// Positive file IDs are in the current translation unit, and -1 is a
1181	// placeholder.
1182	if (FID.ID >= -1)
1183	return std::make_pair(x: SourceLocation(), y: "");
1184
1185	return ExternalSLocEntries->getModuleImportLoc(ID: FID.ID);
1186	}
1187
1188	/// Given a SourceLocation object \p Loc, return the expansion
1189	/// location referenced by the ID.
1190	SourceLocation getExpansionLoc(SourceLocation Loc) const {
1191	// Handle the non-mapped case inline, defer to out of line code to handle
1192	// expansions.
1193	if (Loc.isFileID()) return Loc;
1194	return getExpansionLocSlowCase(Loc);
1195	}
1196
1197	/// Given \p Loc, if it is a macro location return the expansion
1198	/// location or the spelling location, depending on if it comes from a
1199	/// macro argument or not.
1200	SourceLocation getFileLoc(SourceLocation Loc) const {
1201	if (Loc.isFileID()) return Loc;
1202	return getFileLocSlowCase(Loc);
1203	}
1204
1205	/// Return the start/end of the expansion information for an
1206	/// expansion location.
1207	///
1208	/// \pre \p Loc is required to be an expansion location.
1209	CharSourceRange getImmediateExpansionRange(SourceLocation Loc) const;
1210
1211	/// Given a SourceLocation object, return the range of
1212	/// tokens covered by the expansion in the ultimate file.
1213	CharSourceRange getExpansionRange(SourceLocation Loc) const;
1214
1215	/// Given a SourceRange object, return the range of
1216	/// tokens or characters covered by the expansion in the ultimate file.
1217	CharSourceRange getExpansionRange(SourceRange Range) const {
1218	SourceLocation Begin = getExpansionRange(Loc: Range.getBegin()).getBegin();
1219	CharSourceRange End = getExpansionRange(Loc: Range.getEnd());
1220	return CharSourceRange(SourceRange(Begin, End.getEnd()),
1221	End.isTokenRange());
1222	}
1223
1224	/// Given a CharSourceRange object, return the range of
1225	/// tokens or characters covered by the expansion in the ultimate file.
1226	CharSourceRange getExpansionRange(CharSourceRange Range) const {
1227	CharSourceRange Expansion = getExpansionRange(Range: Range.getAsRange());
1228	if (Expansion.getEnd() == Range.getEnd())
1229	Expansion.setTokenRange(Range.isTokenRange());
1230	return Expansion;
1231	}
1232
1233	/// Given a SourceLocation object, return the spelling
1234	/// location referenced by the ID.
1235	///
1236	/// This is the place where the characters that make up the lexed token
1237	/// can be found.
1238	SourceLocation getSpellingLoc(SourceLocation Loc) const {
1239	// Handle the non-mapped case inline, defer to out of line code to handle
1240	// expansions.
1241	if (Loc.isFileID()) return Loc;
1242	return getSpellingLocSlowCase(Loc);
1243	}
1244
1245	/// Given a SourceLocation object, return the spelling location
1246	/// referenced by the ID.
1247	///
1248	/// This is the first level down towards the place where the characters
1249	/// that make up the lexed token can be found. This should not generally
1250	/// be used by clients.
1251	SourceLocation getImmediateSpellingLoc(SourceLocation Loc) const;
1252
1253	/// Form a SourceLocation from a FileID and Offset pair.
1254	SourceLocation getComposedLoc(FileID FID, unsigned Offset) const {
1255	auto *Entry = getSLocEntryOrNull(FID);
1256	if (!Entry)
1257	return SourceLocation();
1258
1259	SourceLocation::UIntTy GlobalOffset = Entry->getOffset() + Offset;
1260	return Entry->isFile() ? SourceLocation::getFileLoc(ID: GlobalOffset)
1261	: SourceLocation::getMacroLoc(ID: GlobalOffset);
1262	}
1263
1264	/// Decompose the specified location into a raw FileID + Offset pair.
1265	///
1266	/// The first element is the FileID, the second is the offset from the
1267	/// start of the buffer of the location.
1268	std::pair<FileID, unsigned> getDecomposedLoc(SourceLocation Loc) const {
1269	FileID FID = getFileID(SpellingLoc: Loc);
1270	auto *Entry = getSLocEntryOrNull(FID);
1271	if (!Entry)
1272	return std::make_pair(x: FileID(), y: 0);
1273	return std::make_pair(x&: FID, y: Loc.getOffset() - Entry->getOffset());
1274	}
1275
1276	/// Decompose the specified location into a raw FileID + Offset pair.
1277	///
1278	/// If the location is an expansion record, walk through it until we find
1279	/// the final location expanded.
1280	std::pair<FileID, unsigned>
1281	getDecomposedExpansionLoc(SourceLocation Loc) const {
1282	FileID FID = getFileID(SpellingLoc: Loc);
1283	auto *E = getSLocEntryOrNull(FID);
1284	if (!E)
1285	return std::make_pair(x: FileID(), y: 0);
1286
1287	unsigned Offset = Loc.getOffset()-E->getOffset();
1288	if (Loc.isFileID())
1289	return std::make_pair(x&: FID, y&: Offset);
1290
1291	return getDecomposedExpansionLocSlowCase(E);
1292	}
1293
1294	/// Decompose the specified location into a raw FileID + Offset pair.
1295	///
1296	/// If the location is an expansion record, walk through it until we find
1297	/// its spelling record.
1298	std::pair<FileID, unsigned>
1299	getDecomposedSpellingLoc(SourceLocation Loc) const {
1300	FileID FID = getFileID(SpellingLoc: Loc);
1301	auto *E = getSLocEntryOrNull(FID);
1302	if (!E)
1303	return std::make_pair(x: FileID(), y: 0);
1304
1305	unsigned Offset = Loc.getOffset()-E->getOffset();
1306	if (Loc.isFileID())
1307	return std::make_pair(x&: FID, y&: Offset);
1308	return getDecomposedSpellingLocSlowCase(E, Offset);
1309	}
1310
1311	/// Returns the "included/expanded in" decomposed location of the given
1312	/// FileID.
1313	std::pair<FileID, unsigned> getDecomposedIncludedLoc(FileID FID) const;
1314
1315	/// Returns the offset from the start of the file that the
1316	/// specified SourceLocation represents.
1317	///
1318	/// This is not very meaningful for a macro ID.
1319	unsigned getFileOffset(SourceLocation SpellingLoc) const {
1320	return getDecomposedLoc(Loc: SpellingLoc).second;
1321	}
1322
1323	/// Tests whether the given source location represents a macro
1324	/// argument's expansion into the function-like macro definition.
1325	///
1326	/// \param StartLoc If non-null and function returns true, it is set to the
1327	/// start location of the macro argument expansion.
1328	///
1329	/// Such source locations only appear inside of the expansion
1330	/// locations representing where a particular function-like macro was
1331	/// expanded.
1332	bool isMacroArgExpansion(SourceLocation Loc,
1333	SourceLocation *StartLoc = nullptr) const;
1334
1335	/// Tests whether the given source location represents the expansion of
1336	/// a macro body.
1337	///
1338	/// This is equivalent to testing whether the location is part of a macro
1339	/// expansion but not the expansion of an argument to a function-like macro.
1340	bool isMacroBodyExpansion(SourceLocation Loc) const;
1341
1342	/// Returns true if the given MacroID location points at the beginning
1343	/// of the immediate macro expansion.
1344	///
1345	/// \param MacroBegin If non-null and function returns true, it is set to the
1346	/// begin location of the immediate macro expansion.
1347	bool isAtStartOfImmediateMacroExpansion(SourceLocation Loc,
1348	SourceLocation *MacroBegin = nullptr) const;
1349
1350	/// Returns true if the given MacroID location points at the character
1351	/// end of the immediate macro expansion.
1352	///
1353	/// \param MacroEnd If non-null and function returns true, it is set to the
1354	/// character end location of the immediate macro expansion.
1355	bool
1356	isAtEndOfImmediateMacroExpansion(SourceLocation Loc,
1357	SourceLocation *MacroEnd = nullptr) const;
1358
1359	/// Returns true if \p Loc is inside the [\p Start, +\p Length)
1360	/// chunk of the source location address space.
1361	///
1362	/// If it's true and \p RelativeOffset is non-null, it will be set to the
1363	/// relative offset of \p Loc inside the chunk.
1364	bool
1365	isInSLocAddrSpace(SourceLocation Loc, SourceLocation Start, unsigned Length,
1366	SourceLocation::UIntTy *RelativeOffset = nullptr) const {
1367	assert(((Start.getOffset() < NextLocalOffset &&
1368	Start.getOffset()+Length <= NextLocalOffset) ||
1369	(Start.getOffset() >= CurrentLoadedOffset &&
1370	Start.getOffset()+Length < MaxLoadedOffset)) &&
1371	"Chunk is not valid SLoc address space");
1372	SourceLocation::UIntTy LocOffs = Loc.getOffset();
1373	SourceLocation::UIntTy BeginOffs = Start.getOffset();
1374	SourceLocation::UIntTy EndOffs = BeginOffs + Length;
1375	if (LocOffs >= BeginOffs && LocOffs < EndOffs) {
1376	if (RelativeOffset)
1377	*RelativeOffset = LocOffs - BeginOffs;
1378	return true;
1379	}
1380
1381	return false;
1382	}
1383
1384	/// Return true if both \p LHS and \p RHS are in the local source
1385	/// location address space or the loaded one.
1386	///
1387	/// If it's true and \p RelativeOffset is non-null, it will be set to the
1388	/// offset of \p RHS relative to \p LHS.
1389	bool isInSameSLocAddrSpace(SourceLocation LHS, SourceLocation RHS,
1390	SourceLocation::IntTy *RelativeOffset) const {
1391	SourceLocation::UIntTy LHSOffs = LHS.getOffset(), RHSOffs = RHS.getOffset();
1392	bool LHSLoaded = LHSOffs >= CurrentLoadedOffset;
1393	bool RHSLoaded = RHSOffs >= CurrentLoadedOffset;
1394
1395	if (LHSLoaded == RHSLoaded) {
1396	if (RelativeOffset)
1397	*RelativeOffset = RHSOffs - LHSOffs;
1398	return true;
1399	}
1400
1401	return false;
1402	}
1403
1404	//===--------------------------------------------------------------------===//
1405	// Queries about the code at a SourceLocation.
1406	//===--------------------------------------------------------------------===//
1407
1408	/// Return a pointer to the start of the specified location
1409	/// in the appropriate spelling MemoryBuffer.
1410	///
1411	/// \param Invalid If non-NULL, will be set \c true if an error occurs.
1412	const char *getCharacterData(SourceLocation SL,
1413	bool *Invalid = nullptr) const;
1414
1415	/// Return the column # for the specified file position.
1416	///
1417	/// This is significantly cheaper to compute than the line number. This
1418	/// returns zero if the column number isn't known. This may only be called
1419	/// on a file sloc, so you must choose a spelling or expansion location
1420	/// before calling this method.
1421	unsigned getColumnNumber(FileID FID, unsigned FilePos,
1422	bool *Invalid = nullptr) const;
1423	unsigned getSpellingColumnNumber(SourceLocation Loc,
1424	bool *Invalid = nullptr) const;
1425	unsigned getExpansionColumnNumber(SourceLocation Loc,
1426	bool *Invalid = nullptr) const;
1427	unsigned getPresumedColumnNumber(SourceLocation Loc,
1428	bool *Invalid = nullptr) const;
1429
1430	/// Given a SourceLocation, return the spelling line number
1431	/// for the position indicated.
1432	///
1433	/// This requires building and caching a table of line offsets for the
1434	/// MemoryBuffer, so this is not cheap: use only when about to emit a
1435	/// diagnostic.
1436	unsigned getLineNumber(FileID FID, unsigned FilePos, bool *Invalid = nullptr) const;
1437	unsigned getSpellingLineNumber(SourceLocation Loc, bool *Invalid = nullptr) const;
1438	unsigned getExpansionLineNumber(SourceLocation Loc, bool *Invalid = nullptr) const;
1439	unsigned getPresumedLineNumber(SourceLocation Loc, bool *Invalid = nullptr) const;
1440
1441	/// Return the filename or buffer identifier of the buffer the
1442	/// location is in.
1443	///
1444	/// Note that this name does not respect \#line directives. Use
1445	/// getPresumedLoc for normal clients.
1446	StringRef getBufferName(SourceLocation Loc, bool *Invalid = nullptr) const;
1447
1448	/// Return the file characteristic of the specified source
1449	/// location, indicating whether this is a normal file, a system
1450	/// header, or an "implicit extern C" system header.
1451	///
1452	/// This state can be modified with flags on GNU linemarker directives like:
1453	/// \code
1454	/// # 4 "foo.h" 3
1455	/// \endcode
1456	/// which changes all source locations in the current file after that to be
1457	/// considered to be from a system header.
1458	SrcMgr::CharacteristicKind getFileCharacteristic(SourceLocation Loc) const;
1459
1460	/// Returns the "presumed" location of a SourceLocation specifies.
1461	///
1462	/// A "presumed location" can be modified by \#line or GNU line marker
1463	/// directives. This provides a view on the data that a user should see
1464	/// in diagnostics, for example.
1465	///
1466	/// Note that a presumed location is always given as the expansion point of
1467	/// an expansion location, not at the spelling location.
1468	///
1469	/// \returns The presumed location of the specified SourceLocation. If the
1470	/// presumed location cannot be calculated (e.g., because \p Loc is invalid
1471	/// or the file containing \p Loc has changed on disk), returns an invalid
1472	/// presumed location.
1473	PresumedLoc getPresumedLoc(SourceLocation Loc,
1474	bool UseLineDirectives = true) const;
1475
1476	/// Returns whether the PresumedLoc for a given SourceLocation is
1477	/// in the main file.
1478	///
1479	/// This computes the "presumed" location for a SourceLocation, then checks
1480	/// whether it came from a file other than the main file. This is different
1481	/// from isWrittenInMainFile() because it takes line marker directives into
1482	/// account.
1483	bool isInMainFile(SourceLocation Loc) const;
1484
1485	/// Returns true if the spelling locations for both SourceLocations
1486	/// are part of the same file buffer.
1487	///
1488	/// This check ignores line marker directives.
1489	bool isWrittenInSameFile(SourceLocation Loc1, SourceLocation Loc2) const {
1490	return getFileID(SpellingLoc: Loc1) == getFileID(SpellingLoc: Loc2);
1491	}
1492
1493	/// Returns true if the spelling location for the given location
1494	/// is in the main file buffer.
1495	///
1496	/// This check ignores line marker directives.
1497	bool isWrittenInMainFile(SourceLocation Loc) const {
1498	return getFileID(SpellingLoc: Loc) == getMainFileID();
1499	}
1500
1501	/// Returns whether \p Loc is located in a <built-in> file.
1502	bool isWrittenInBuiltinFile(SourceLocation Loc) const {
1503	PresumedLoc Presumed = getPresumedLoc(Loc);
1504	if (Presumed.isInvalid())
1505	return false;
1506	StringRef Filename(Presumed.getFilename());
1507	return Filename.equals(RHS: "<built-in>");
1508	}
1509
1510	/// Returns whether \p Loc is located in a <command line> file.
1511	bool isWrittenInCommandLineFile(SourceLocation Loc) const {
1512	PresumedLoc Presumed = getPresumedLoc(Loc);
1513	if (Presumed.isInvalid())
1514	return false;
1515	StringRef Filename(Presumed.getFilename());
1516	return Filename.equals(RHS: "<command line>");
1517	}
1518
1519	/// Returns whether \p Loc is located in a <scratch space> file.
1520	bool isWrittenInScratchSpace(SourceLocation Loc) const {
1521	PresumedLoc Presumed = getPresumedLoc(Loc);
1522	if (Presumed.isInvalid())
1523	return false;
1524	StringRef Filename(Presumed.getFilename());
1525	return Filename.equals(RHS: "<scratch space>");
1526	}
1527
1528	/// Returns if a SourceLocation is in a system header.
1529	bool isInSystemHeader(SourceLocation Loc) const {
1530	if (Loc.isInvalid())
1531	return false;
1532	return isSystem(CK: getFileCharacteristic(Loc));
1533	}
1534
1535	/// Returns if a SourceLocation is in an "extern C" system header.
1536	bool isInExternCSystemHeader(SourceLocation Loc) const {
1537	return getFileCharacteristic(Loc) == SrcMgr::C_ExternCSystem;
1538	}
1539
1540	/// Returns whether \p Loc is expanded from a macro in a system header.
1541	bool isInSystemMacro(SourceLocation loc) const {
1542	if (!loc.isMacroID())
1543	return false;
1544
1545	// This happens when the macro is the result of a paste, in that case
1546	// its spelling is the scratch memory, so we take the parent context.
1547	// There can be several level of token pasting.
1548	if (isWrittenInScratchSpace(Loc: getSpellingLoc(Loc: loc))) {
1549	do {
1550	loc = getImmediateMacroCallerLoc(Loc: loc);
1551	} while (isWrittenInScratchSpace(Loc: getSpellingLoc(Loc: loc)));
1552	return isInSystemMacro(loc);
1553	}
1554
1555	return isInSystemHeader(Loc: getSpellingLoc(Loc: loc));
1556	}
1557
1558	/// The size of the SLocEntry that \p FID represents.
1559	unsigned getFileIDSize(FileID FID) const;
1560
1561	/// Given a specific FileID, returns true if \p Loc is inside that
1562	/// FileID chunk and sets relative offset (offset of \p Loc from beginning
1563	/// of FileID) to \p relativeOffset.
1564	bool isInFileID(SourceLocation Loc, FileID FID,
1565	unsigned *RelativeOffset = nullptr) const {
1566	SourceLocation::UIntTy Offs = Loc.getOffset();
1567	if (isOffsetInFileID(FID, SLocOffset: Offs)) {
1568	if (RelativeOffset)
1569	*RelativeOffset = Offs - getSLocEntry(FID).getOffset();
1570	return true;
1571	}
1572
1573	return false;
1574	}
1575
1576	//===--------------------------------------------------------------------===//
1577	// Line Table Manipulation Routines
1578	//===--------------------------------------------------------------------===//
1579
1580	/// Return the uniqued ID for the specified filename.
1581	unsigned getLineTableFilenameID(StringRef Str);
1582
1583	/// Add a line note to the line table for the FileID and offset
1584	/// specified by Loc.
1585	///
1586	/// If FilenameID is -1, it is considered to be unspecified.
1587	void AddLineNote(SourceLocation Loc, unsigned LineNo, int FilenameID,
1588	bool IsFileEntry, bool IsFileExit,
1589	SrcMgr::CharacteristicKind FileKind);
1590
1591	/// Determine if the source manager has a line table.
1592	bool hasLineTable() const { return LineTable != nullptr; }
1593
1594	/// Retrieve the stored line table.
1595	LineTableInfo &getLineTable();
1596
1597	//===--------------------------------------------------------------------===//
1598	// Queries for performance analysis.
1599	//===--------------------------------------------------------------------===//
1600
1601	/// Return the total amount of physical memory allocated by the
1602	/// ContentCache allocator.
1603	size_t getContentCacheSize() const {
1604	return ContentCacheAlloc.getTotalMemory();
1605	}
1606
1607	struct MemoryBufferSizes {
1608	const size_t malloc_bytes;
1609	const size_t mmap_bytes;
1610
1611	MemoryBufferSizes(size_t malloc_bytes, size_t mmap_bytes)
1612	: malloc_bytes(malloc_bytes), mmap_bytes(mmap_bytes) {}
1613	};
1614
1615	/// Return the amount of memory used by memory buffers, breaking down
1616	/// by heap-backed versus mmap'ed memory.
1617	MemoryBufferSizes getMemoryBufferSizes() const;
1618
1619	/// Return the amount of memory used for various side tables and
1620	/// data structures in the SourceManager.
1621	size_t getDataStructureSizes() const;
1622
1623	//===--------------------------------------------------------------------===//
1624	// Other miscellaneous methods.
1625	//===--------------------------------------------------------------------===//
1626
1627	/// Get the source location for the given file:line:col triplet.
1628	///
1629	/// If the source file is included multiple times, the source location will
1630	/// be based upon the first inclusion.
1631	SourceLocation translateFileLineCol(const FileEntry *SourceFile,
1632	unsigned Line, unsigned Col) const;
1633
1634	/// Get the FileID for the given file.
1635	///
1636	/// If the source file is included multiple times, the FileID will be the
1637	/// first inclusion.
1638	FileID translateFile(const FileEntry *SourceFile) const;
1639	FileID translateFile(FileEntryRef SourceFile) const {
1640	return translateFile(SourceFile: &SourceFile.getFileEntry());
1641	}
1642
1643	/// Get the source location in \p FID for the given line:col.
1644	/// Returns null location if \p FID is not a file SLocEntry.
1645	SourceLocation translateLineCol(FileID FID,
1646	unsigned Line, unsigned Col) const;
1647
1648	/// If \p Loc points inside a function macro argument, the returned
1649	/// location will be the macro location in which the argument was expanded.
1650	/// If a macro argument is used multiple times, the expanded location will
1651	/// be at the first expansion of the argument.
1652	/// e.g.
1653	/// MY_MACRO(foo);
1654	/// ^
1655	/// Passing a file location pointing at 'foo', will yield a macro location
1656	/// where 'foo' was expanded into.
1657	SourceLocation getMacroArgExpandedLocation(SourceLocation Loc) const;
1658
1659	/// Determines the order of 2 source locations in the translation unit.
1660	///
1661	/// \returns true if LHS source location comes before RHS, false otherwise.
1662	bool isBeforeInTranslationUnit(SourceLocation LHS, SourceLocation RHS) const;
1663
1664	/// Determines whether the two decomposed source location is in the
1665	/// same translation unit. As a byproduct, it also calculates the order
1666	/// of the source locations in case they are in the same TU.
1667	///
1668	/// \returns Pair of bools the first component is true if the two locations
1669	/// are in the same TU. The second bool is true if the first is true
1670	/// and \p LOffs is before \p ROffs.
1671	std::pair<bool, bool>
1672	isInTheSameTranslationUnit(std::pair<FileID, unsigned> &LOffs,
1673	std::pair<FileID, unsigned> &ROffs) const;
1674
1675	/// Determines whether the two decomposed source location is in the same TU.
1676	bool isInTheSameTranslationUnitImpl(
1677	const std::pair<FileID, unsigned> &LOffs,
1678	const std::pair<FileID, unsigned> &ROffs) const;
1679
1680	/// Determines the order of 2 source locations in the "source location
1681	/// address space".
1682	bool isBeforeInSLocAddrSpace(SourceLocation LHS, SourceLocation RHS) const {
1683	return isBeforeInSLocAddrSpace(LHS, RHS: RHS.getOffset());
1684	}
1685
1686	/// Determines the order of a source location and a source location
1687	/// offset in the "source location address space".
1688	///
1689	/// Note that we always consider source locations loaded from
1690	bool isBeforeInSLocAddrSpace(SourceLocation LHS,
1691	SourceLocation::UIntTy RHS) const {
1692	SourceLocation::UIntTy LHSOffset = LHS.getOffset();
1693	bool LHSLoaded = LHSOffset >= CurrentLoadedOffset;
1694	bool RHSLoaded = RHS >= CurrentLoadedOffset;
1695	if (LHSLoaded == RHSLoaded)
1696	return LHSOffset < RHS;
1697
1698	return LHSLoaded;
1699	}
1700
1701	/// Return true if the Point is within Start and End.
1702	bool isPointWithin(SourceLocation Location, SourceLocation Start,
1703	SourceLocation End) const {
1704	return Location == Start || Location == End ||
1705	(isBeforeInTranslationUnit(LHS: Start, RHS: Location) &&
1706	isBeforeInTranslationUnit(LHS: Location, RHS: End));
1707	}
1708
1709	// Iterators over FileInfos.
1710	using fileinfo_iterator =
1711	llvm::DenseMap<FileEntryRef, SrcMgr::ContentCache *>::const_iterator;
1712
1713	fileinfo_iterator fileinfo_begin() const { return FileInfos.begin(); }
1714	fileinfo_iterator fileinfo_end() const { return FileInfos.end(); }
1715	bool hasFileInfo(const FileEntry *File) const {
1716	return FileInfos.find_as(Val: File) != FileInfos.end();
1717	}
1718
1719	/// Print statistics to stderr.
1720	void PrintStats() const;
1721
1722	void dump() const;
1723
1724	// Produce notes describing the current source location address space usage.
1725	void noteSLocAddressSpaceUsage(DiagnosticsEngine &Diag,
1726	std::optional<unsigned> MaxNotes = 32) const;
1727
1728	/// Get the number of local SLocEntries we have.
1729	unsigned local_sloc_entry_size() const { return LocalSLocEntryTable.size(); }
1730
1731	/// Get a local SLocEntry. This is exposed for indexing.
1732	const SrcMgr::SLocEntry &getLocalSLocEntry(unsigned Index) const {
1733	assert(Index < LocalSLocEntryTable.size() && "Invalid index");
1734	return LocalSLocEntryTable[Index];
1735	}
1736
1737	/// Get the number of loaded SLocEntries we have.
1738	unsigned loaded_sloc_entry_size() const { return LoadedSLocEntryTable.size();}
1739
1740	/// Get a loaded SLocEntry. This is exposed for indexing.
1741	const SrcMgr::SLocEntry &getLoadedSLocEntry(unsigned Index,
1742	bool *Invalid = nullptr) const {
1743	assert(Index < LoadedSLocEntryTable.size() && "Invalid index");
1744	if (SLocEntryLoaded[Index])
1745	return LoadedSLocEntryTable[Index];
1746	return loadSLocEntry(Index, Invalid);
1747	}
1748
1749	const SrcMgr::SLocEntry &getSLocEntry(FileID FID,
1750	bool *Invalid = nullptr) const {
1751	if (FID.ID == 0 || FID.ID == -1) {
1752	if (Invalid) *Invalid = true;
1753	return LocalSLocEntryTable[0];
1754	}
1755	return getSLocEntryByID(ID: FID.ID, Invalid);
1756	}
1757
1758	SourceLocation::UIntTy getNextLocalOffset() const { return NextLocalOffset; }
1759
1760	void setExternalSLocEntrySource(ExternalSLocEntrySource *Source) {
1761	assert(LoadedSLocEntryTable.empty() &&
1762	"Invalidating existing loaded entries");
1763	ExternalSLocEntries = Source;
1764	}
1765
1766	/// Allocate a number of loaded SLocEntries, which will be actually
1767	/// loaded on demand from the external source.
1768	///
1769	/// NumSLocEntries will be allocated, which occupy a total of TotalSize space
1770	/// in the global source view. The lowest ID and the base offset of the
1771	/// entries will be returned.
1772	std::pair<int, SourceLocation::UIntTy>
1773	AllocateLoadedSLocEntries(unsigned NumSLocEntries,
1774	SourceLocation::UIntTy TotalSize);
1775
1776	/// Returns true if \p Loc came from a PCH/Module.
1777	bool isLoadedSourceLocation(SourceLocation Loc) const {
1778	return isLoadedOffset(SLocOffset: Loc.getOffset());
1779	}
1780
1781	/// Returns true if \p Loc did not come from a PCH/Module.
1782	bool isLocalSourceLocation(SourceLocation Loc) const {
1783	return isLocalOffset(SLocOffset: Loc.getOffset());
1784	}
1785
1786	/// Returns true if \p FID came from a PCH/Module.
1787	bool isLoadedFileID(FileID FID) const {
1788	assert(FID.ID != -1 && "Using FileID sentinel value");
1789	return FID.ID < 0;
1790	}
1791
1792	/// Returns true if \p FID did not come from a PCH/Module.
1793	bool isLocalFileID(FileID FID) const {
1794	return !isLoadedFileID(FID);
1795	}
1796
1797	/// Gets the location of the immediate macro caller, one level up the stack
1798	/// toward the initial macro typed into the source.
1799	SourceLocation getImmediateMacroCallerLoc(SourceLocation Loc) const {
1800	if (!Loc.isMacroID()) return Loc;
1801
1802	// When we have the location of (part of) an expanded parameter, its
1803	// spelling location points to the argument as expanded in the macro call,
1804	// and therefore is used to locate the macro caller.
1805	if (isMacroArgExpansion(Loc))
1806	return getImmediateSpellingLoc(Loc);
1807
1808	// Otherwise, the caller of the macro is located where this macro is
1809	// expanded (while the spelling is part of the macro definition).
1810	return getImmediateExpansionRange(Loc).getBegin();
1811	}
1812
1813	/// \return Location of the top-level macro caller.
1814	SourceLocation getTopMacroCallerLoc(SourceLocation Loc) const;
1815
1816	private:
1817	friend class ASTReader;
1818	friend class ASTWriter;
1819
1820	llvm::MemoryBufferRef getFakeBufferForRecovery() const;
1821	SrcMgr::ContentCache &getFakeContentCacheForRecovery() const;
1822
1823	const SrcMgr::SLocEntry &loadSLocEntry(unsigned Index, bool *Invalid) const;
1824
1825	const SrcMgr::SLocEntry *getSLocEntryOrNull(FileID FID) const {
1826	bool Invalid = false;
1827	const SrcMgr::SLocEntry &Entry = getSLocEntry(FID, Invalid: &Invalid);
1828	return Invalid ? nullptr : &Entry;
1829	}
1830
1831	const SrcMgr::SLocEntry *getSLocEntryForFile(FileID FID) const {
1832	if (auto *Entry = getSLocEntryOrNull(FID))
1833	if (Entry->isFile())
1834	return Entry;
1835	return nullptr;
1836	}
1837
1838	/// Get the entry with the given unwrapped FileID.
1839	/// Invalid will not be modified for Local IDs.
1840	const SrcMgr::SLocEntry &getSLocEntryByID(int ID,
1841	bool *Invalid = nullptr) const {
1842	assert(ID != -1 && "Using FileID sentinel value");
1843	if (ID < 0)
1844	return getLoadedSLocEntryByID(ID, Invalid);
1845	return getLocalSLocEntry(Index: static_cast<unsigned>(ID));
1846	}
1847
1848	const SrcMgr::SLocEntry &
1849	getLoadedSLocEntryByID(int ID, bool *Invalid = nullptr) const {
1850	return getLoadedSLocEntry(Index: static_cast<unsigned>(-ID - 2), Invalid);
1851	}
1852
1853	FileID getFileID(SourceLocation::UIntTy SLocOffset) const {
1854	// If our one-entry cache covers this offset, just return it.
1855	if (isOffsetInFileID(FID: LastFileIDLookup, SLocOffset))
1856	return LastFileIDLookup;
1857
1858	return getFileIDSlow(SLocOffset);
1859	}
1860
1861	bool isLocalOffset(SourceLocation::UIntTy SLocOffset) const {
1862	return SLocOffset < CurrentLoadedOffset;
1863	}
1864
1865	bool isLoadedOffset(SourceLocation::UIntTy SLocOffset) const {
1866	return SLocOffset >= CurrentLoadedOffset;
1867	}
1868
1869	/// Implements the common elements of storing an expansion info struct into
1870	/// the SLocEntry table and producing a source location that refers to it.
1871	SourceLocation
1872	createExpansionLocImpl(const SrcMgr::ExpansionInfo &Expansion,
1873	unsigned Length, int LoadedID = 0,
1874	SourceLocation::UIntTy LoadedOffset = 0);
1875
1876	/// Return true if the specified FileID contains the
1877	/// specified SourceLocation offset. This is a very hot method.
1878	inline bool isOffsetInFileID(FileID FID,
1879	SourceLocation::UIntTy SLocOffset) const {
1880	const SrcMgr::SLocEntry &Entry = getSLocEntry(FID);
1881	// If the entry is after the offset, it can't contain it.
1882	if (SLocOffset < Entry.getOffset()) return false;
1883
1884	// If this is the very last entry then it does.
1885	if (FID.ID == -2)
1886	return true;
1887
1888	// If it is the last local entry, then it does if the location is local.
1889	if (FID.ID+1 == static_cast<int>(LocalSLocEntryTable.size()))
1890	return SLocOffset < NextLocalOffset;
1891
1892	// Otherwise, the entry after it has to not include it. This works for both
1893	// local and loaded entries.
1894	return SLocOffset < getSLocEntryByID(ID: FID.ID+1).getOffset();
1895	}
1896
1897	/// Returns the previous in-order FileID or an invalid FileID if there
1898	/// is no previous one.
1899	FileID getPreviousFileID(FileID FID) const;
1900
1901	/// Returns the next in-order FileID or an invalid FileID if there is
1902	/// no next one.
1903	FileID getNextFileID(FileID FID) const;
1904
1905	/// Create a new fileID for the specified ContentCache and
1906	/// include position.
1907	///
1908	/// This works regardless of whether the ContentCache corresponds to a
1909	/// file or some other input source.
1910	FileID createFileIDImpl(SrcMgr::ContentCache &File, StringRef Filename,
1911	SourceLocation IncludePos,
1912	SrcMgr::CharacteristicKind DirCharacter, int LoadedID,
1913	SourceLocation::UIntTy LoadedOffset);
1914
1915	SrcMgr::ContentCache &getOrCreateContentCache(FileEntryRef SourceFile,
1916	bool isSystemFile = false);
1917
1918	/// Create a new ContentCache for the specified memory buffer.
1919	SrcMgr::ContentCache &
1920	createMemBufferContentCache(std::unique_ptr<llvm::MemoryBuffer> Buf);
1921
1922	FileID getFileIDSlow(SourceLocation::UIntTy SLocOffset) const;
1923	FileID getFileIDLocal(SourceLocation::UIntTy SLocOffset) const;
1924	FileID getFileIDLoaded(SourceLocation::UIntTy SLocOffset) const;
1925
1926	SourceLocation getExpansionLocSlowCase(SourceLocation Loc) const;
1927	SourceLocation getSpellingLocSlowCase(SourceLocation Loc) const;
1928	SourceLocation getFileLocSlowCase(SourceLocation Loc) const;
1929
1930	std::pair<FileID, unsigned>
1931	getDecomposedExpansionLocSlowCase(const SrcMgr::SLocEntry *E) const;
1932	std::pair<FileID, unsigned>
1933	getDecomposedSpellingLocSlowCase(const SrcMgr::SLocEntry *E,
1934	unsigned Offset) const;
1935	void computeMacroArgsCache(MacroArgsMap &MacroArgsCache, FileID FID) const;
1936	void associateFileChunkWithMacroArgExp(MacroArgsMap &MacroArgsCache,
1937	FileID FID,
1938	SourceLocation SpellLoc,
1939	SourceLocation ExpansionLoc,
1940	unsigned ExpansionLength) const;
1941	};
1942
1943	/// Comparison function object.
1944	template<typename T>
1945	class BeforeThanCompare;
1946
1947	/// Compare two source locations.
1948	template<>
1949	class BeforeThanCompare<SourceLocation> {
1950	SourceManager &SM;
1951
1952	public:
1953	explicit BeforeThanCompare(SourceManager &SM) : SM(SM) {}
1954
1955	bool operator()(SourceLocation LHS, SourceLocation RHS) const {
1956	return SM.isBeforeInTranslationUnit(LHS, RHS);
1957	}
1958	};
1959
1960	/// Compare two non-overlapping source ranges.
1961	template<>
1962	class BeforeThanCompare<SourceRange> {
1963	SourceManager &SM;
1964
1965	public:
1966	explicit BeforeThanCompare(SourceManager &SM) : SM(SM) {}
1967
1968	bool operator()(SourceRange LHS, SourceRange RHS) const {
1969	return SM.isBeforeInTranslationUnit(LHS: LHS.getBegin(), RHS: RHS.getBegin());
1970	}
1971	};
1972
1973	/// SourceManager and necessary dependencies (e.g. VFS, FileManager) for a
1974	/// single in-memorty file.
1975	class SourceManagerForFile {
1976	public:
1977	/// Creates SourceManager and necessary dependencies (e.g. VFS, FileManager).
1978	/// The main file in the SourceManager will be \p FileName with \p Content.
1979	SourceManagerForFile(StringRef FileName, StringRef Content);
1980
1981	SourceManager &get() {
1982	assert(SourceMgr);
1983	return *SourceMgr;
1984	}
1985
1986	private:
1987	// The order of these fields are important - they should be in the same order
1988	// as they are created in `createSourceManagerForFile` so that they can be
1989	// deleted in the reverse order as they are created.
1990	std::unique_ptr<FileManager> FileMgr;
1991	std::unique_ptr<DiagnosticsEngine> Diagnostics;
1992	std::unique_ptr<SourceManager> SourceMgr;
1993	};
1994
1995	} // namespace clang
1996
1997	#endif // LLVM_CLANG_BASIC_SOURCEMANAGER_H
1998