1	//===- HeaderSearch.cpp - Resolve Header File Locations -------------------===//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	// This file implements the DirectoryLookup and HeaderSearch interfaces.
10	//
11	//===----------------------------------------------------------------------===//
12
13	#include "clang/Lex/HeaderSearch.h"
14	#include "clang/Basic/Diagnostic.h"
15	#include "clang/Basic/FileManager.h"
16	#include "clang/Basic/IdentifierTable.h"
17	#include "clang/Basic/Module.h"
18	#include "clang/Basic/SourceManager.h"
19	#include "clang/Lex/DirectoryLookup.h"
20	#include "clang/Lex/ExternalPreprocessorSource.h"
21	#include "clang/Lex/HeaderMap.h"
22	#include "clang/Lex/HeaderSearchOptions.h"
23	#include "clang/Lex/LexDiagnostic.h"
24	#include "clang/Lex/ModuleMap.h"
25	#include "clang/Lex/Preprocessor.h"
26	#include "llvm/ADT/APInt.h"
27	#include "llvm/ADT/Hashing.h"
28	#include "llvm/ADT/SmallString.h"
29	#include "llvm/ADT/SmallVector.h"
30	#include "llvm/ADT/Statistic.h"
31	#include "llvm/ADT/StringRef.h"
32	#include "llvm/ADT/STLExtras.h"
33	#include "llvm/Support/Allocator.h"
34	#include "llvm/Support/Capacity.h"
35	#include "llvm/Support/Errc.h"
36	#include "llvm/Support/ErrorHandling.h"
37	#include "llvm/Support/FileSystem.h"
38	#include "llvm/Support/Path.h"
39	#include "llvm/Support/VirtualFileSystem.h"
40	#include <algorithm>
41	#include <cassert>
42	#include <cstddef>
43	#include <cstdio>
44	#include <cstring>
45	#include <string>
46	#include <system_error>
47	#include <utility>
48
49	using namespace clang;
50
51	#define DEBUG_TYPE "file-search"
52
53	ALWAYS_ENABLED_STATISTIC(NumIncluded, "Number of attempted #includes.");
54	ALWAYS_ENABLED_STATISTIC(
55	NumMultiIncludeFileOptzn,
56	"Number of #includes skipped due to the multi-include optimization.");
57	ALWAYS_ENABLED_STATISTIC(NumFrameworkLookups, "Number of framework lookups.");
58	ALWAYS_ENABLED_STATISTIC(NumSubFrameworkLookups,
59	"Number of subframework lookups.");
60
61	const IdentifierInfo *
62	HeaderFileInfo::getControllingMacro(ExternalPreprocessorSource *External) {
63	if (ControllingMacro) {
64	if (ControllingMacro->isOutOfDate()) {
65	assert(External && "We must have an external source if we have a "
66	"controlling macro that is out of date.");
67	External->updateOutOfDateIdentifier(II: *ControllingMacro);
68	}
69	return ControllingMacro;
70	}
71
72	if (!ControllingMacroID || !External)
73	return nullptr;
74
75	ControllingMacro = External->GetIdentifier(ID: ControllingMacroID);
76	return ControllingMacro;
77	}
78
79	ExternalHeaderFileInfoSource::~ExternalHeaderFileInfoSource() = default;
80
81	HeaderSearch::HeaderSearch(std::shared_ptr<HeaderSearchOptions> HSOpts,
82	SourceManager &SourceMgr, DiagnosticsEngine &Diags,
83	const LangOptions &LangOpts,
84	const TargetInfo *Target)
85	: HSOpts(std::move(HSOpts)), Diags(Diags),
86	FileMgr(SourceMgr.getFileManager()), FrameworkMap(64),
87	ModMap(SourceMgr, Diags, LangOpts, Target, *this) {}
88
89	void HeaderSearch::PrintStats() {
90	llvm::errs() << "\n*** HeaderSearch Stats:\n"
91	<< FileInfo.size() << " files tracked.\n";
92	unsigned NumOnceOnlyFiles = 0;
93	for (unsigned i = 0, e = FileInfo.size(); i != e; ++i)
94	NumOnceOnlyFiles += (FileInfo[i].isPragmaOnce || FileInfo[i].isImport);
95	llvm::errs() << " " << NumOnceOnlyFiles << " #import/#pragma once files.\n";
96
97	llvm::errs() << " " << NumIncluded << " #include/#include_next/#import.\n"
98	<< " " << NumMultiIncludeFileOptzn
99	<< " #includes skipped due to the multi-include optimization.\n";
100
101	llvm::errs() << NumFrameworkLookups << " framework lookups.\n"
102	<< NumSubFrameworkLookups << " subframework lookups.\n";
103	}
104
105	void HeaderSearch::SetSearchPaths(
106	std::vector<DirectoryLookup> dirs, unsigned int angledDirIdx,
107	unsigned int systemDirIdx,
108	llvm::DenseMap<unsigned int, unsigned int> searchDirToHSEntry) {
109	assert(angledDirIdx <= systemDirIdx && systemDirIdx <= dirs.size() &&
110	"Directory indices are unordered");
111	SearchDirs = std::move(dirs);
112	SearchDirsUsage.assign(n: SearchDirs.size(), x: false);
113	AngledDirIdx = angledDirIdx;
114	SystemDirIdx = systemDirIdx;
115	SearchDirToHSEntry = std::move(searchDirToHSEntry);
116	//LookupFileCache.clear();
117	indexInitialHeaderMaps();
118	}
119
120	void HeaderSearch::AddSearchPath(const DirectoryLookup &dir, bool isAngled) {
121	unsigned idx = isAngled ? SystemDirIdx : AngledDirIdx;
122	SearchDirs.insert(position: SearchDirs.begin() + idx, x: dir);
123	SearchDirsUsage.insert(position: SearchDirsUsage.begin() + idx, x: false);
124	if (!isAngled)
125	AngledDirIdx++;
126	SystemDirIdx++;
127	}
128
129	std::vector<bool> HeaderSearch::computeUserEntryUsage() const {
130	std::vector<bool> UserEntryUsage(HSOpts->UserEntries.size());
131	for (unsigned I = 0, E = SearchDirsUsage.size(); I < E; ++I) {
132	// Check whether this DirectoryLookup has been successfully used.
133	if (SearchDirsUsage[I]) {
134	auto UserEntryIdxIt = SearchDirToHSEntry.find(Val: I);
135	// Check whether this DirectoryLookup maps to a HeaderSearch::UserEntry.
136	if (UserEntryIdxIt != SearchDirToHSEntry.end())
137	UserEntryUsage[UserEntryIdxIt->second] = true;
138	}
139	}
140	return UserEntryUsage;
141	}
142
143	std::vector<bool> HeaderSearch::collectVFSUsageAndClear() const {
144	std::vector<bool> VFSUsage;
145	if (!getHeaderSearchOpts().ModulesIncludeVFSUsage)
146	return VFSUsage;
147
148	llvm::vfs::FileSystem &RootFS = FileMgr.getVirtualFileSystem();
149	// TODO: This only works if the `RedirectingFileSystem`s were all created by
150	// `createVFSFromOverlayFiles`.
151	RootFS.visit(Callback: [&](llvm::vfs::FileSystem &FS) {
152	if (auto *RFS = dyn_cast<llvm::vfs::RedirectingFileSystem>(Val: &FS)) {
153	VFSUsage.push_back(x: RFS->hasBeenUsed());
154	RFS->clearHasBeenUsed();
155	}
156	});
157	assert(VFSUsage.size() == getHeaderSearchOpts().VFSOverlayFiles.size() &&
158	"A different number of RedirectingFileSystem's were present than "
159	"-ivfsoverlay options passed to Clang!");
160	// VFS visit order is the opposite of VFSOverlayFiles order.
161	std::reverse(first: VFSUsage.begin(), last: VFSUsage.end());
162	return VFSUsage;
163	}
164
165	/// CreateHeaderMap - This method returns a HeaderMap for the specified
166	/// FileEntry, uniquing them through the 'HeaderMaps' datastructure.
167	const HeaderMap *HeaderSearch::CreateHeaderMap(FileEntryRef FE) {
168	// We expect the number of headermaps to be small, and almost always empty.
169	// If it ever grows, use of a linear search should be re-evaluated.
170	if (!HeaderMaps.empty()) {
171	for (unsigned i = 0, e = HeaderMaps.size(); i != e; ++i)
172	// Pointer equality comparison of FileEntries works because they are
173	// already uniqued by inode.
174	if (HeaderMaps[i].first == FE)
175	return HeaderMaps[i].second.get();
176	}
177
178	if (std::unique_ptr<HeaderMap> HM = HeaderMap::Create(FE, FM&: FileMgr)) {
179	HeaderMaps.emplace_back(args&: FE, args: std::move(HM));
180	return HeaderMaps.back().second.get();
181	}
182
183	return nullptr;
184	}
185
186	/// Get filenames for all registered header maps.
187	void HeaderSearch::getHeaderMapFileNames(
188	SmallVectorImpl<std::string> &Names) const {
189	for (auto &HM : HeaderMaps)
190	Names.push_back(Elt: std::string(HM.first.getName()));
191	}
192
193	std::string HeaderSearch::getCachedModuleFileName(Module *Module) {
194	OptionalFileEntryRef ModuleMap =
195	getModuleMap().getModuleMapFileForUniquing(M: Module);
196	// The ModuleMap maybe a nullptr, when we load a cached C++ module without
197	// *.modulemap file. In this case, just return an empty string.
198	if (!ModuleMap)
199	return {};
200	return getCachedModuleFileName(ModuleName: Module->Name, ModuleMapPath: ModuleMap->getNameAsRequested());
201	}
202
203	std::string HeaderSearch::getPrebuiltModuleFileName(StringRef ModuleName,
204	bool FileMapOnly) {
205	// First check the module name to pcm file map.
206	auto i(HSOpts->PrebuiltModuleFiles.find(x: ModuleName));
207	if (i != HSOpts->PrebuiltModuleFiles.end())
208	return i->second;
209
210	if (FileMapOnly || HSOpts->PrebuiltModulePaths.empty())
211	return {};
212
213	// Then go through each prebuilt module directory and try to find the pcm
214	// file.
215	for (const std::string &Dir : HSOpts->PrebuiltModulePaths) {
216	SmallString<256> Result(Dir);
217	llvm::sys::fs::make_absolute(path&: Result);
218	if (ModuleName.contains(C: ':'))
219	// The separator of C++20 modules partitions (':') is not good for file
220	// systems, here clang and gcc choose '-' by default since it is not a
221	// valid character of C++ indentifiers. So we could avoid conflicts.
222	llvm::sys::path::append(path&: Result, a: ModuleName.split(Separator: ':').first + "-" +
223	ModuleName.split(Separator: ':').second +
224	".pcm");
225	else
226	llvm::sys::path::append(path&: Result, a: ModuleName + ".pcm");
227	if (getFileMgr().getFile(Filename: Result.str()))
228	return std::string(Result);
229	}
230
231	return {};
232	}
233
234	std::string HeaderSearch::getPrebuiltImplicitModuleFileName(Module *Module) {
235	OptionalFileEntryRef ModuleMap =
236	getModuleMap().getModuleMapFileForUniquing(M: Module);
237	StringRef ModuleName = Module->Name;
238	StringRef ModuleMapPath = ModuleMap->getName();
239	StringRef ModuleCacheHash = HSOpts->DisableModuleHash ? "" : getModuleHash();
240	for (const std::string &Dir : HSOpts->PrebuiltModulePaths) {
241	SmallString<256> CachePath(Dir);
242	llvm::sys::fs::make_absolute(path&: CachePath);
243	llvm::sys::path::append(path&: CachePath, a: ModuleCacheHash);
244	std::string FileName =
245	getCachedModuleFileNameImpl(ModuleName, ModuleMapPath, CachePath);
246	if (!FileName.empty() && getFileMgr().getFile(Filename: FileName))
247	return FileName;
248	}
249	return {};
250	}
251
252	std::string HeaderSearch::getCachedModuleFileName(StringRef ModuleName,
253	StringRef ModuleMapPath) {
254	return getCachedModuleFileNameImpl(ModuleName, ModuleMapPath,
255	CachePath: getModuleCachePath());
256	}
257
258	std::string HeaderSearch::getCachedModuleFileNameImpl(StringRef ModuleName,
259	StringRef ModuleMapPath,
260	StringRef CachePath) {
261	// If we don't have a module cache path or aren't supposed to use one, we
262	// can't do anything.
263	if (CachePath.empty())
264	return {};
265
266	SmallString<256> Result(CachePath);
267	llvm::sys::fs::make_absolute(path&: Result);
268
269	if (HSOpts->DisableModuleHash) {
270	llvm::sys::path::append(path&: Result, a: ModuleName + ".pcm");
271	} else {
272	// Construct the name <ModuleName>-<hash of ModuleMapPath>.pcm which should
273	// ideally be globally unique to this particular module. Name collisions
274	// in the hash are safe (because any translation unit can only import one
275	// module with each name), but result in a loss of caching.
276	//
277	// To avoid false-negatives, we form as canonical a path as we can, and map
278	// to lower-case in case we're on a case-insensitive file system.
279	SmallString<128> CanonicalPath(ModuleMapPath);
280	if (getModuleMap().canonicalizeModuleMapPath(Path&: CanonicalPath))
281	return {};
282
283	llvm::hash_code Hash = llvm::hash_combine(args: CanonicalPath.str().lower());
284
285	SmallString<128> HashStr;
286	llvm::APInt(64, size_t(Hash)).toStringUnsigned(Str&: HashStr, /*Radix*/36);
287	llvm::sys::path::append(path&: Result, a: ModuleName + "-" + HashStr + ".pcm");
288	}
289	return Result.str().str();
290	}
291
292	Module *HeaderSearch::lookupModule(StringRef ModuleName,
293	SourceLocation ImportLoc, bool AllowSearch,
294	bool AllowExtraModuleMapSearch) {
295	// Look in the module map to determine if there is a module by this name.
296	Module *Module = ModMap.findModule(Name: ModuleName);
297	if (Module || !AllowSearch || !HSOpts->ImplicitModuleMaps)
298	return Module;
299
300	StringRef SearchName = ModuleName;
301	Module = lookupModule(ModuleName, SearchName, ImportLoc,
302	AllowExtraModuleMapSearch);
303
304	// The facility for "private modules" -- adjacent, optional module maps named
305	// module.private.modulemap that are supposed to define private submodules --
306	// may have different flavors of names: FooPrivate, Foo_Private and Foo.Private.
307	//
308	// Foo.Private is now deprecated in favor of Foo_Private. Users of FooPrivate
309	// should also rename to Foo_Private. Representing private as submodules
310	// could force building unwanted dependencies into the parent module and cause
311	// dependency cycles.
312	if (!Module && SearchName.consume_back(Suffix: "_Private"))
313	Module = lookupModule(ModuleName, SearchName, ImportLoc,
314	AllowExtraModuleMapSearch);
315	if (!Module && SearchName.consume_back(Suffix: "Private"))
316	Module = lookupModule(ModuleName, SearchName, ImportLoc,
317	AllowExtraModuleMapSearch);
318	return Module;
319	}
320
321	Module *HeaderSearch::lookupModule(StringRef ModuleName, StringRef SearchName,
322	SourceLocation ImportLoc,
323	bool AllowExtraModuleMapSearch) {
324	Module *Module = nullptr;
325
326	// Look through the various header search paths to load any available module
327	// maps, searching for a module map that describes this module.
328	for (DirectoryLookup &Dir : search_dir_range()) {
329	if (Dir.isFramework()) {
330	// Search for or infer a module map for a framework. Here we use
331	// SearchName rather than ModuleName, to permit finding private modules
332	// named FooPrivate in buggy frameworks named Foo.
333	SmallString<128> FrameworkDirName;
334	FrameworkDirName += Dir.getFrameworkDirRef()->getName();
335	llvm::sys::path::append(path&: FrameworkDirName, a: SearchName + ".framework");
336	if (auto FrameworkDir =
337	FileMgr.getOptionalDirectoryRef(DirName: FrameworkDirName)) {
338	bool IsSystem = Dir.getDirCharacteristic() != SrcMgr::C_User;
339	Module = loadFrameworkModule(Name: ModuleName, Dir: *FrameworkDir, IsSystem);
340	if (Module)
341	break;
342	}
343	}
344
345	// FIXME: Figure out how header maps and module maps will work together.
346
347	// Only deal with normal search directories.
348	if (!Dir.isNormalDir())
349	continue;
350
351	bool IsSystem = Dir.isSystemHeaderDirectory();
352	// Only returns std::nullopt if not a normal directory, which we just
353	// checked
354	DirectoryEntryRef NormalDir = *Dir.getDirRef();
355	// Search for a module map file in this directory.
356	if (loadModuleMapFile(Dir: NormalDir, IsSystem,
357	/*IsFramework*/false) == LMM_NewlyLoaded) {
358	// We just loaded a module map file; check whether the module is
359	// available now.
360	Module = ModMap.findModule(Name: ModuleName);
361	if (Module)
362	break;
363	}
364
365	// Search for a module map in a subdirectory with the same name as the
366	// module.
367	SmallString<128> NestedModuleMapDirName;
368	NestedModuleMapDirName = Dir.getDirRef()->getName();
369	llvm::sys::path::append(path&: NestedModuleMapDirName, a: ModuleName);
370	if (loadModuleMapFile(DirName: NestedModuleMapDirName, IsSystem,
371	/*IsFramework*/false) == LMM_NewlyLoaded){
372	// If we just loaded a module map file, look for the module again.
373	Module = ModMap.findModule(Name: ModuleName);
374	if (Module)
375	break;
376	}
377
378	// If we've already performed the exhaustive search for module maps in this
379	// search directory, don't do it again.
380	if (Dir.haveSearchedAllModuleMaps())
381	continue;
382
383	// Load all module maps in the immediate subdirectories of this search
384	// directory if ModuleName was from @import.
385	if (AllowExtraModuleMapSearch)
386	loadSubdirectoryModuleMaps(SearchDir&: Dir);
387
388	// Look again for the module.
389	Module = ModMap.findModule(Name: ModuleName);
390	if (Module)
391	break;
392	}
393
394	return Module;
395	}
396
397	void HeaderSearch::indexInitialHeaderMaps() {
398	llvm::StringMap<unsigned, llvm::BumpPtrAllocator> Index(SearchDirs.size());
399
400	// Iterate over all filename keys and associate them with the index i.
401	for (unsigned i = 0; i != SearchDirs.size(); ++i) {
402	auto &Dir = SearchDirs[i];
403
404	// We're concerned with only the initial contiguous run of header
405	// maps within SearchDirs, which can be 99% of SearchDirs when
406	// SearchDirs.size() is ~10000.
407	if (!Dir.isHeaderMap()) {
408	SearchDirHeaderMapIndex = std::move(Index);
409	FirstNonHeaderMapSearchDirIdx = i;
410	break;
411	}
412
413	// Give earlier keys precedence over identical later keys.
414	auto Callback = [&](StringRef Filename) {
415	Index.try_emplace(Key: Filename.lower(), Args&: i);
416	};
417	Dir.getHeaderMap()->forEachKey(Callback);
418	}
419	}
420
421	//===----------------------------------------------------------------------===//
422	// File lookup within a DirectoryLookup scope
423	//===----------------------------------------------------------------------===//
424
425	/// getName - Return the directory or filename corresponding to this lookup
426	/// object.
427	StringRef DirectoryLookup::getName() const {
428	if (isNormalDir())
429	return getDirRef()->getName();
430	if (isFramework())
431	return getFrameworkDirRef()->getName();
432	assert(isHeaderMap() && "Unknown DirectoryLookup");
433	return getHeaderMap()->getFileName();
434	}
435
436	OptionalFileEntryRef HeaderSearch::getFileAndSuggestModule(
437	StringRef FileName, SourceLocation IncludeLoc, const DirectoryEntry *Dir,
438	bool IsSystemHeaderDir, Module *RequestingModule,
439	ModuleMap::KnownHeader *SuggestedModule, bool OpenFile /*=true*/,
440	bool CacheFailures /*=true*/) {
441	// If we have a module map that might map this header, load it and
442	// check whether we'll have a suggestion for a module.
443	auto File = getFileMgr().getFileRef(Filename: FileName, OpenFile, CacheFailure: CacheFailures);
444	if (!File) {
445	// For rare, surprising errors (e.g. "out of file handles"), diag the EC
446	// message.
447	std::error_code EC = llvm::errorToErrorCode(Err: File.takeError());
448	if (EC != llvm::errc::no_such_file_or_directory &&
449	EC != llvm::errc::invalid_argument &&
450	EC != llvm::errc::is_a_directory && EC != llvm::errc::not_a_directory) {
451	Diags.Report(IncludeLoc, diag::err_cannot_open_file)
452	<< FileName << EC.message();
453	}
454	return std::nullopt;
455	}
456
457	// If there is a module that corresponds to this header, suggest it.
458	if (!findUsableModuleForHeader(
459	File: *File, Root: Dir ? Dir : File->getFileEntry().getDir(), RequestingModule,
460	SuggestedModule, IsSystemHeaderDir))
461	return std::nullopt;
462
463	return *File;
464	}
465
466	/// LookupFile - Lookup the specified file in this search path, returning it
467	/// if it exists or returning null if not.
468	OptionalFileEntryRef DirectoryLookup::LookupFile(
469	StringRef &Filename, HeaderSearch &HS, SourceLocation IncludeLoc,
470	SmallVectorImpl<char> *SearchPath, SmallVectorImpl<char> *RelativePath,
471	Module *RequestingModule, ModuleMap::KnownHeader *SuggestedModule,
472	bool &InUserSpecifiedSystemFramework, bool &IsFrameworkFound,
473	bool &IsInHeaderMap, SmallVectorImpl<char> &MappedName,
474	bool OpenFile) const {
475	InUserSpecifiedSystemFramework = false;
476	IsInHeaderMap = false;
477	MappedName.clear();
478
479	SmallString<1024> TmpDir;
480	if (isNormalDir()) {
481	// Concatenate the requested file onto the directory.
482	TmpDir = getDirRef()->getName();
483	llvm::sys::path::append(path&: TmpDir, a: Filename);
484	if (SearchPath) {
485	StringRef SearchPathRef(getDirRef()->getName());
486	SearchPath->clear();
487	SearchPath->append(in_start: SearchPathRef.begin(), in_end: SearchPathRef.end());
488	}
489	if (RelativePath) {
490	RelativePath->clear();
491	RelativePath->append(in_start: Filename.begin(), in_end: Filename.end());
492	}
493
494	return HS.getFileAndSuggestModule(
495	FileName: TmpDir, IncludeLoc, Dir: getDir(), IsSystemHeaderDir: isSystemHeaderDirectory(),
496	RequestingModule, SuggestedModule, OpenFile);
497	}
498
499	if (isFramework())
500	return DoFrameworkLookup(Filename, HS, SearchPath, RelativePath,
501	RequestingModule, SuggestedModule,
502	InUserSpecifiedSystemFramework, IsFrameworkFound);
503
504	assert(isHeaderMap() && "Unknown directory lookup");
505	const HeaderMap *HM = getHeaderMap();
506	SmallString<1024> Path;
507	StringRef Dest = HM->lookupFilename(Filename, DestPath&: Path);
508	if (Dest.empty())
509	return std::nullopt;
510
511	IsInHeaderMap = true;
512
513	auto FixupSearchPathAndFindUsableModule =
514	[&](FileEntryRef File) -> OptionalFileEntryRef {
515	if (SearchPath) {
516	StringRef SearchPathRef(getName());
517	SearchPath->clear();
518	SearchPath->append(in_start: SearchPathRef.begin(), in_end: SearchPathRef.end());
519	}
520	if (RelativePath) {
521	RelativePath->clear();
522	RelativePath->append(in_start: Filename.begin(), in_end: Filename.end());
523	}
524	if (!HS.findUsableModuleForHeader(File, Root: File.getFileEntry().getDir(),
525	RequestingModule, SuggestedModule,
526	IsSystemHeaderDir: isSystemHeaderDirectory())) {
527	return std::nullopt;
528	}
529	return File;
530	};
531
532	// Check if the headermap maps the filename to a framework include
533	// ("Foo.h" -> "Foo/Foo.h"), in which case continue header lookup using the
534	// framework include.
535	if (llvm::sys::path::is_relative(path: Dest)) {
536	MappedName.append(in_start: Dest.begin(), in_end: Dest.end());
537	Filename = StringRef(MappedName.begin(), MappedName.size());
538	Dest = HM->lookupFilename(Filename, DestPath&: Path);
539	}
540
541	if (auto Res = HS.getFileMgr().getOptionalFileRef(Filename: Dest, OpenFile)) {
542	return FixupSearchPathAndFindUsableModule(*Res);
543	}
544
545	// Header maps need to be marked as used whenever the filename matches.
546	// The case where the target file **exists** is handled by callee of this
547	// function as part of the regular logic that applies to include search paths.
548	// The case where the target file **does not exist** is handled here:
549	HS.noteLookupUsage(HitIdx: HS.searchDirIdx(DL: *this), IncludeLoc);
550	return std::nullopt;
551	}
552
553	/// Given a framework directory, find the top-most framework directory.
554	///
555	/// \param FileMgr The file manager to use for directory lookups.
556	/// \param DirName The name of the framework directory.
557	/// \param SubmodulePath Will be populated with the submodule path from the
558	/// returned top-level module to the originally named framework.
559	static OptionalDirectoryEntryRef
560	getTopFrameworkDir(FileManager &FileMgr, StringRef DirName,
561	SmallVectorImpl<std::string> &SubmodulePath) {
562	assert(llvm::sys::path::extension(DirName) == ".framework" &&
563	"Not a framework directory");
564
565	// Note: as an egregious but useful hack we use the real path here, because
566	// frameworks moving between top-level frameworks to embedded frameworks tend
567	// to be symlinked, and we base the logical structure of modules on the
568	// physical layout. In particular, we need to deal with crazy includes like
569	//
570	// #include <Foo/Frameworks/Bar.framework/Headers/Wibble.h>
571	//
572	// where 'Bar' used to be embedded in 'Foo', is now a top-level framework
573	// which one should access with, e.g.,
574	//
575	// #include <Bar/Wibble.h>
576	//
577	// Similar issues occur when a top-level framework has moved into an
578	// embedded framework.
579	auto TopFrameworkDir = FileMgr.getOptionalDirectoryRef(DirName);
580
581	if (TopFrameworkDir)
582	DirName = FileMgr.getCanonicalName(Dir: *TopFrameworkDir);
583	do {
584	// Get the parent directory name.
585	DirName = llvm::sys::path::parent_path(path: DirName);
586	if (DirName.empty())
587	break;
588
589	// Determine whether this directory exists.
590	auto Dir = FileMgr.getOptionalDirectoryRef(DirName);
591	if (!Dir)
592	break;
593
594	// If this is a framework directory, then we're a subframework of this
595	// framework.
596	if (llvm::sys::path::extension(path: DirName) == ".framework") {
597	SubmodulePath.push_back(Elt: std::string(llvm::sys::path::stem(path: DirName)));
598	TopFrameworkDir = *Dir;
599	}
600	} while (true);
601
602	return TopFrameworkDir;
603	}
604
605	static bool needModuleLookup(Module *RequestingModule,
606	bool HasSuggestedModule) {
607	return HasSuggestedModule ||
608	(RequestingModule && RequestingModule->NoUndeclaredIncludes);
609	}
610
611	/// DoFrameworkLookup - Do a lookup of the specified file in the current
612	/// DirectoryLookup, which is a framework directory.
613	OptionalFileEntryRef DirectoryLookup::DoFrameworkLookup(
614	StringRef Filename, HeaderSearch &HS, SmallVectorImpl<char> *SearchPath,
615	SmallVectorImpl<char> *RelativePath, Module *RequestingModule,
616	ModuleMap::KnownHeader *SuggestedModule,
617	bool &InUserSpecifiedSystemFramework, bool &IsFrameworkFound) const {
618	FileManager &FileMgr = HS.getFileMgr();
619
620	// Framework names must have a '/' in the filename.
621	size_t SlashPos = Filename.find(C: '/');
622	if (SlashPos == StringRef::npos)
623	return std::nullopt;
624
625	// Find out if this is the home for the specified framework, by checking
626	// HeaderSearch. Possible answers are yes/no and unknown.
627	FrameworkCacheEntry &CacheEntry =
628	HS.LookupFrameworkCache(FWName: Filename.substr(Start: 0, N: SlashPos));
629
630	// If it is known and in some other directory, fail.
631	if (CacheEntry.Directory && CacheEntry.Directory != getFrameworkDirRef())
632	return std::nullopt;
633
634	// Otherwise, construct the path to this framework dir.
635
636	// FrameworkName = "/System/Library/Frameworks/"
637	SmallString<1024> FrameworkName;
638	FrameworkName += getFrameworkDirRef()->getName();
639	if (FrameworkName.empty() || FrameworkName.back() != '/')
640	FrameworkName.push_back(Elt: '/');
641
642	// FrameworkName = "/System/Library/Frameworks/Cocoa"
643	StringRef ModuleName(Filename.begin(), SlashPos);
644	FrameworkName += ModuleName;
645
646	// FrameworkName = "/System/Library/Frameworks/Cocoa.framework/"
647	FrameworkName += ".framework/";
648
649	// If the cache entry was unresolved, populate it now.
650	if (!CacheEntry.Directory) {
651	++NumFrameworkLookups;
652
653	// If the framework dir doesn't exist, we fail.
654	auto Dir = FileMgr.getDirectory(DirName: FrameworkName);
655	if (!Dir)
656	return std::nullopt;
657
658	// Otherwise, if it does, remember that this is the right direntry for this
659	// framework.
660	CacheEntry.Directory = getFrameworkDirRef();
661
662	// If this is a user search directory, check if the framework has been
663	// user-specified as a system framework.
664	if (getDirCharacteristic() == SrcMgr::C_User) {
665	SmallString<1024> SystemFrameworkMarker(FrameworkName);
666	SystemFrameworkMarker += ".system_framework";
667	if (llvm::sys::fs::exists(Path: SystemFrameworkMarker)) {
668	CacheEntry.IsUserSpecifiedSystemFramework = true;
669	}
670	}
671	}
672
673	// Set out flags.
674	InUserSpecifiedSystemFramework = CacheEntry.IsUserSpecifiedSystemFramework;
675	IsFrameworkFound = CacheEntry.Directory.has_value();
676
677	if (RelativePath) {
678	RelativePath->clear();
679	RelativePath->append(in_start: Filename.begin()+SlashPos+1, in_end: Filename.end());
680	}
681
682	// Check "/System/Library/Frameworks/Cocoa.framework/Headers/file.h"
683	unsigned OrigSize = FrameworkName.size();
684
685	FrameworkName += "Headers/";
686
687	if (SearchPath) {
688	SearchPath->clear();
689	// Without trailing '/'.
690	SearchPath->append(in_start: FrameworkName.begin(), in_end: FrameworkName.end()-1);
691	}
692
693	FrameworkName.append(in_start: Filename.begin()+SlashPos+1, in_end: Filename.end());
694
695	auto File =
696	FileMgr.getOptionalFileRef(Filename: FrameworkName, /*OpenFile=*/!SuggestedModule);
697	if (!File) {
698	// Check "/System/Library/Frameworks/Cocoa.framework/PrivateHeaders/file.h"
699	const char *Private = "Private";
700	FrameworkName.insert(I: FrameworkName.begin()+OrigSize, From: Private,
701	To: Private+strlen(s: Private));
702	if (SearchPath)
703	SearchPath->insert(I: SearchPath->begin()+OrigSize, From: Private,
704	To: Private+strlen(s: Private));
705
706	File = FileMgr.getOptionalFileRef(Filename: FrameworkName,
707	/*OpenFile=*/!SuggestedModule);
708	}
709
710	// If we found the header and are allowed to suggest a module, do so now.
711	if (File && needModuleLookup(RequestingModule, HasSuggestedModule: SuggestedModule)) {
712	// Find the framework in which this header occurs.
713	StringRef FrameworkPath = File->getDir().getName();
714	bool FoundFramework = false;
715	do {
716	// Determine whether this directory exists.
717	auto Dir = FileMgr.getDirectory(DirName: FrameworkPath);
718	if (!Dir)
719	break;
720
721	// If this is a framework directory, then we're a subframework of this
722	// framework.
723	if (llvm::sys::path::extension(path: FrameworkPath) == ".framework") {
724	FoundFramework = true;
725	break;
726	}
727
728	// Get the parent directory name.
729	FrameworkPath = llvm::sys::path::parent_path(path: FrameworkPath);
730	if (FrameworkPath.empty())
731	break;
732	} while (true);
733
734	bool IsSystem = getDirCharacteristic() != SrcMgr::C_User;
735	if (FoundFramework) {
736	if (!HS.findUsableModuleForFrameworkHeader(File: *File, FrameworkName: FrameworkPath,
737	RequestingModule,
738	SuggestedModule, IsSystemFramework: IsSystem))
739	return std::nullopt;
740	} else {
741	if (!HS.findUsableModuleForHeader(File: *File, Root: getDir(), RequestingModule,
742	SuggestedModule, IsSystemHeaderDir: IsSystem))
743	return std::nullopt;
744	}
745	}
746	if (File)
747	return *File;
748	return std::nullopt;
749	}
750
751	void HeaderSearch::cacheLookupSuccess(LookupFileCacheInfo &CacheLookup,
752	ConstSearchDirIterator HitIt,
753	SourceLocation Loc) {
754	CacheLookup.HitIt = HitIt;
755	noteLookupUsage(HitIdx: HitIt.Idx, IncludeLoc: Loc);
756	}
757
758	void HeaderSearch::noteLookupUsage(unsigned HitIdx, SourceLocation Loc) {
759	SearchDirsUsage[HitIdx] = true;
760
761	auto UserEntryIdxIt = SearchDirToHSEntry.find(Val: HitIdx);
762	if (UserEntryIdxIt != SearchDirToHSEntry.end())
763	Diags.Report(Loc, diag::remark_pp_search_path_usage)
764	<< HSOpts->UserEntries[UserEntryIdxIt->second].Path;
765	}
766
767	void HeaderSearch::setTarget(const TargetInfo &Target) {
768	ModMap.setTarget(Target);
769	}
770
771	//===----------------------------------------------------------------------===//
772	// Header File Location.
773	//===----------------------------------------------------------------------===//
774
775	/// Return true with a diagnostic if the file that MSVC would have found
776	/// fails to match the one that Clang would have found with MSVC header search
777	/// disabled.
778	static bool checkMSVCHeaderSearch(DiagnosticsEngine &Diags,
779	OptionalFileEntryRef MSFE,
780	const FileEntry *FE,
781	SourceLocation IncludeLoc) {
782	if (MSFE && FE != *MSFE) {
783	Diags.Report(IncludeLoc, diag::ext_pp_include_search_ms) << MSFE->getName();
784	return true;
785	}
786	return false;
787	}
788
789	static const char *copyString(StringRef Str, llvm::BumpPtrAllocator &Alloc) {
790	assert(!Str.empty());
791	char *CopyStr = Alloc.Allocate<char>(Num: Str.size()+1);
792	std::copy(first: Str.begin(), last: Str.end(), result: CopyStr);
793	CopyStr[Str.size()] = '\0';
794	return CopyStr;
795	}
796
797	static bool isFrameworkStylePath(StringRef Path, bool &IsPrivateHeader,
798	SmallVectorImpl<char> &FrameworkName,
799	SmallVectorImpl<char> &IncludeSpelling) {
800	using namespace llvm::sys;
801	path::const_iterator I = path::begin(path: Path);
802	path::const_iterator E = path::end(path: Path);
803	IsPrivateHeader = false;
804
805	// Detect different types of framework style paths:
806	//
807	// ...Foo.framework/{Headers,PrivateHeaders}
808	// ...Foo.framework/Versions/{A,Current}/{Headers,PrivateHeaders}
809	// ...Foo.framework/Frameworks/Nested.framework/{Headers,PrivateHeaders}
810	// ...<other variations with 'Versions' like in the above path>
811	//
812	// and some other variations among these lines.
813	int FoundComp = 0;
814	while (I != E) {
815	if (*I == "Headers") {
816	++FoundComp;
817	} else if (*I == "PrivateHeaders") {
818	++FoundComp;
819	IsPrivateHeader = true;
820	} else if (I->ends_with(Suffix: ".framework")) {
821	StringRef Name = I->drop_back(N: 10); // Drop .framework
822	// Need to reset the strings and counter to support nested frameworks.
823	FrameworkName.clear();
824	FrameworkName.append(in_start: Name.begin(), in_end: Name.end());
825	IncludeSpelling.clear();
826	IncludeSpelling.append(in_start: Name.begin(), in_end: Name.end());
827	FoundComp = 1;
828	} else if (FoundComp >= 2) {
829	IncludeSpelling.push_back(Elt: '/');
830	IncludeSpelling.append(in_start: I->begin(), in_end: I->end());
831	}
832	++I;
833	}
834
835	return !FrameworkName.empty() && FoundComp >= 2;
836	}
837
838	static void
839	diagnoseFrameworkInclude(DiagnosticsEngine &Diags, SourceLocation IncludeLoc,
840	StringRef Includer, StringRef IncludeFilename,
841	FileEntryRef IncludeFE, bool isAngled = false,
842	bool FoundByHeaderMap = false) {
843	bool IsIncluderPrivateHeader = false;
844	SmallString<128> FromFramework, ToFramework;
845	SmallString<128> FromIncludeSpelling, ToIncludeSpelling;
846	if (!isFrameworkStylePath(Path: Includer, IsPrivateHeader&: IsIncluderPrivateHeader, FrameworkName&: FromFramework,
847	IncludeSpelling&: FromIncludeSpelling))
848	return;
849	bool IsIncludeePrivateHeader = false;
850	bool IsIncludeeInFramework =
851	isFrameworkStylePath(Path: IncludeFE.getName(), IsPrivateHeader&: IsIncludeePrivateHeader,
852	FrameworkName&: ToFramework, IncludeSpelling&: ToIncludeSpelling);
853
854	if (!isAngled && !FoundByHeaderMap) {
855	SmallString<128> NewInclude("<");
856	if (IsIncludeeInFramework) {
857	NewInclude += ToIncludeSpelling;
858	NewInclude += ">";
859	} else {
860	NewInclude += IncludeFilename;
861	NewInclude += ">";
862	}
863	Diags.Report(IncludeLoc, diag::warn_quoted_include_in_framework_header)
864	<< IncludeFilename
865	<< FixItHint::CreateReplacement(RemoveRange: IncludeLoc, Code: NewInclude);
866	}
867
868	// Headers in Foo.framework/Headers should not include headers
869	// from Foo.framework/PrivateHeaders, since this violates public/private
870	// API boundaries and can cause modular dependency cycles.
871	if (!IsIncluderPrivateHeader && IsIncludeeInFramework &&
872	IsIncludeePrivateHeader && FromFramework == ToFramework)
873	Diags.Report(IncludeLoc, diag::warn_framework_include_private_from_public)
874	<< IncludeFilename;
875	}
876
877	/// LookupFile - Given a "foo" or \<foo> reference, look up the indicated file,
878	/// return null on failure. isAngled indicates whether the file reference is
879	/// for system \#include's or not (i.e. using <> instead of ""). Includers, if
880	/// non-empty, indicates where the \#including file(s) are, in case a relative
881	/// search is needed. Microsoft mode will pass all \#including files.
882	OptionalFileEntryRef HeaderSearch::LookupFile(
883	StringRef Filename, SourceLocation IncludeLoc, bool isAngled,
884	ConstSearchDirIterator FromDir, ConstSearchDirIterator *CurDirArg,
885	ArrayRef<std::pair<OptionalFileEntryRef, DirectoryEntryRef>> Includers,
886	SmallVectorImpl<char> *SearchPath, SmallVectorImpl<char> *RelativePath,
887	Module *RequestingModule, ModuleMap::KnownHeader *SuggestedModule,
888	bool *IsMapped, bool *IsFrameworkFound, bool SkipCache,
889	bool BuildSystemModule, bool OpenFile, bool CacheFailures) {
890	ConstSearchDirIterator CurDirLocal = nullptr;
891	ConstSearchDirIterator &CurDir = CurDirArg ? *CurDirArg : CurDirLocal;
892
893	if (IsMapped)
894	*IsMapped = false;
895
896	if (IsFrameworkFound)
897	*IsFrameworkFound = false;
898
899	if (SuggestedModule)
900	*SuggestedModule = ModuleMap::KnownHeader();
901
902	// If 'Filename' is absolute, check to see if it exists and no searching.
903	if (llvm::sys::path::is_absolute(path: Filename)) {
904	CurDir = nullptr;
905
906	// If this was an #include_next "/absolute/file", fail.
907	if (FromDir)
908	return std::nullopt;
909
910	if (SearchPath)
911	SearchPath->clear();
912	if (RelativePath) {
913	RelativePath->clear();
914	RelativePath->append(in_start: Filename.begin(), in_end: Filename.end());
915	}
916	// Otherwise, just return the file.
917	return getFileAndSuggestModule(FileName: Filename, IncludeLoc, Dir: nullptr,
918	/*IsSystemHeaderDir*/ false,
919	RequestingModule, SuggestedModule, OpenFile,
920	CacheFailures);
921	}
922
923	// This is the header that MSVC's header search would have found.
924	ModuleMap::KnownHeader MSSuggestedModule;
925	OptionalFileEntryRef MSFE;
926
927	// Check to see if the file is in the #includer's directory. This cannot be
928	// based on CurDir, because each includer could be a #include of a
929	// subdirectory (#include "foo/bar.h") and a subsequent include of "baz.h"
930	// should resolve to "whatever/foo/baz.h". This search is not done for <>
931	// headers.
932	if (!Includers.empty() && !isAngled) {
933	SmallString<1024> TmpDir;
934	bool First = true;
935	for (const auto &IncluderAndDir : Includers) {
936	OptionalFileEntryRef Includer = IncluderAndDir.first;
937
938	// Concatenate the requested file onto the directory.
939	TmpDir = IncluderAndDir.second.getName();
940	llvm::sys::path::append(path&: TmpDir, a: Filename);
941
942	// FIXME: We don't cache the result of getFileInfo across the call to
943	// getFileAndSuggestModule, because it's a reference to an element of
944	// a container that could be reallocated across this call.
945	//
946	// If we have no includer, that means we're processing a #include
947	// from a module build. We should treat this as a system header if we're
948	// building a [system] module.
949	bool IncluderIsSystemHeader = [&]() {
950	if (!Includer)
951	return BuildSystemModule;
952	const HeaderFileInfo *HFI = getExistingFileInfo(FE: *Includer);
953	assert(HFI && "includer without file info");
954	return HFI->DirInfo != SrcMgr::C_User;
955	}();
956	if (OptionalFileEntryRef FE = getFileAndSuggestModule(
957	FileName: TmpDir, IncludeLoc, Dir: IncluderAndDir.second, IsSystemHeaderDir: IncluderIsSystemHeader,
958	RequestingModule, SuggestedModule)) {
959	if (!Includer) {
960	assert(First && "only first includer can have no file");
961	return FE;
962	}
963
964	// Leave CurDir unset.
965	// This file is a system header or C++ unfriendly if the old file is.
966	//
967	// Note that we only use one of FromHFI/ToHFI at once, due to potential
968	// reallocation of the underlying vector potentially making the first
969	// reference binding dangling.
970	const HeaderFileInfo *FromHFI = getExistingFileInfo(FE: *Includer);
971	assert(FromHFI && "includer without file info");
972	unsigned DirInfo = FromHFI->DirInfo;
973	bool IndexHeaderMapHeader = FromHFI->IndexHeaderMapHeader;
974	StringRef Framework = FromHFI->Framework;
975
976	HeaderFileInfo &ToHFI = getFileInfo(FE: *FE);
977	ToHFI.DirInfo = DirInfo;
978	ToHFI.IndexHeaderMapHeader = IndexHeaderMapHeader;
979	ToHFI.Framework = Framework;
980
981	if (SearchPath) {
982	StringRef SearchPathRef(IncluderAndDir.second.getName());
983	SearchPath->clear();
984	SearchPath->append(in_start: SearchPathRef.begin(), in_end: SearchPathRef.end());
985	}
986	if (RelativePath) {
987	RelativePath->clear();
988	RelativePath->append(in_start: Filename.begin(), in_end: Filename.end());
989	}
990	if (First) {
991	diagnoseFrameworkInclude(Diags, IncludeLoc,
992	Includer: IncluderAndDir.second.getName(), IncludeFilename: Filename,
993	IncludeFE: *FE);
994	return FE;
995	}
996
997	// Otherwise, we found the path via MSVC header search rules. If
998	// -Wmsvc-include is enabled, we have to keep searching to see if we
999	// would've found this header in -I or -isystem directories.
1000	if (Diags.isIgnored(diag::DiagID: ext_pp_include_search_ms, Loc: IncludeLoc)) {
1001	return FE;
1002	} else {
1003	MSFE = FE;
1004	if (SuggestedModule) {
1005	MSSuggestedModule = *SuggestedModule;
1006	*SuggestedModule = ModuleMap::KnownHeader();
1007	}
1008	break;
1009	}
1010	}
1011	First = false;
1012	}
1013	}
1014
1015	CurDir = nullptr;
1016
1017	// If this is a system #include, ignore the user #include locs.
1018	ConstSearchDirIterator It =
1019	isAngled ? angled_dir_begin() : search_dir_begin();
1020
1021	// If this is a #include_next request, start searching after the directory the
1022	// file was found in.
1023	if (FromDir)
1024	It = FromDir;
1025
1026	// Cache all of the lookups performed by this method. Many headers are
1027	// multiply included, and the "pragma once" optimization prevents them from
1028	// being relex/pp'd, but they would still have to search through a
1029	// (potentially huge) series of SearchDirs to find it.
1030	LookupFileCacheInfo &CacheLookup = LookupFileCache[Filename];
1031
1032	ConstSearchDirIterator NextIt = std::next(x: It);
1033
1034	if (!SkipCache) {
1035	if (CacheLookup.StartIt == NextIt &&
1036	CacheLookup.RequestingModule == RequestingModule) {
1037	// HIT: Skip querying potentially lots of directories for this lookup.
1038	if (CacheLookup.HitIt)
1039	It = CacheLookup.HitIt;
1040	if (CacheLookup.MappedName) {
1041	Filename = CacheLookup.MappedName;
1042	if (IsMapped)
1043	*IsMapped = true;
1044	}
1045	} else {
1046	// MISS: This is the first query, or the previous query didn't match
1047	// our search start. We will fill in our found location below, so prime
1048	// the start point value.
1049	CacheLookup.reset(NewRequestingModule: RequestingModule, /*NewStartIt=*/NextIt);
1050
1051	if (It == search_dir_begin() && FirstNonHeaderMapSearchDirIdx > 0) {
1052	// Handle cold misses of user includes in the presence of many header
1053	// maps. We avoid searching perhaps thousands of header maps by
1054	// jumping directly to the correct one or jumping beyond all of them.
1055	auto Iter = SearchDirHeaderMapIndex.find(Key: Filename.lower());
1056	if (Iter == SearchDirHeaderMapIndex.end())
1057	// Not in index => Skip to first SearchDir after initial header maps
1058	It = search_dir_nth(n: FirstNonHeaderMapSearchDirIdx);
1059	else
1060	// In index => Start with a specific header map
1061	It = search_dir_nth(n: Iter->second);
1062	}
1063	}
1064	} else {
1065	CacheLookup.reset(NewRequestingModule: RequestingModule, /*NewStartIt=*/NextIt);
1066	}
1067
1068	SmallString<64> MappedName;
1069
1070	// Check each directory in sequence to see if it contains this file.
1071	for (; It != search_dir_end(); ++It) {
1072	bool InUserSpecifiedSystemFramework = false;
1073	bool IsInHeaderMap = false;
1074	bool IsFrameworkFoundInDir = false;
1075	OptionalFileEntryRef File = It->LookupFile(
1076	Filename, HS&: *this, IncludeLoc, SearchPath, RelativePath, RequestingModule,
1077	SuggestedModule, InUserSpecifiedSystemFramework, IsFrameworkFound&: IsFrameworkFoundInDir,
1078	IsInHeaderMap, MappedName, OpenFile);
1079	if (!MappedName.empty()) {
1080	assert(IsInHeaderMap && "MappedName should come from a header map");
1081	CacheLookup.MappedName =
1082	copyString(Str: MappedName, Alloc&: LookupFileCache.getAllocator());
1083	}
1084	if (IsMapped)
1085	// A filename is mapped when a header map remapped it to a relative path
1086	// used in subsequent header search or to an absolute path pointing to an
1087	// existing file.
1088	*IsMapped |= (!MappedName.empty() || (IsInHeaderMap && File));
1089	if (IsFrameworkFound)
1090	// Because we keep a filename remapped for subsequent search directory
1091	// lookups, ignore IsFrameworkFoundInDir after the first remapping and not
1092	// just for remapping in a current search directory.
1093	*IsFrameworkFound |= (IsFrameworkFoundInDir && !CacheLookup.MappedName);
1094	if (!File)
1095	continue;
1096
1097	CurDir = It;
1098
1099	IncludeNames[*File] = Filename;
1100
1101	// This file is a system header or C++ unfriendly if the dir is.
1102	HeaderFileInfo &HFI = getFileInfo(FE: *File);
1103	HFI.DirInfo = CurDir->getDirCharacteristic();
1104
1105	// If the directory characteristic is User but this framework was
1106	// user-specified to be treated as a system framework, promote the
1107	// characteristic.
1108	if (HFI.DirInfo == SrcMgr::C_User && InUserSpecifiedSystemFramework)
1109	HFI.DirInfo = SrcMgr::C_System;
1110
1111	// If the filename matches a known system header prefix, override
1112	// whether the file is a system header.
1113	for (unsigned j = SystemHeaderPrefixes.size(); j; --j) {
1114	if (Filename.starts_with(Prefix: SystemHeaderPrefixes[j - 1].first)) {
1115	HFI.DirInfo = SystemHeaderPrefixes[j-1].second ? SrcMgr::C_System
1116	: SrcMgr::C_User;
1117	break;
1118	}
1119	}
1120
1121	// Set the `Framework` info if this file is in a header map with framework
1122	// style include spelling or found in a framework dir. The header map case
1123	// is possible when building frameworks which use header maps.
1124	if (CurDir->isHeaderMap() && isAngled) {
1125	size_t SlashPos = Filename.find(C: '/');
1126	if (SlashPos != StringRef::npos)
1127	HFI.Framework =
1128	getUniqueFrameworkName(Framework: StringRef(Filename.begin(), SlashPos));
1129	if (CurDir->isIndexHeaderMap())
1130	HFI.IndexHeaderMapHeader = 1;
1131	} else if (CurDir->isFramework()) {
1132	size_t SlashPos = Filename.find(C: '/');
1133	if (SlashPos != StringRef::npos)
1134	HFI.Framework =
1135	getUniqueFrameworkName(Framework: StringRef(Filename.begin(), SlashPos));
1136	}
1137
1138	if (checkMSVCHeaderSearch(Diags, MSFE, FE: &File->getFileEntry(), IncludeLoc)) {
1139	if (SuggestedModule)
1140	*SuggestedModule = MSSuggestedModule;
1141	return MSFE;
1142	}
1143
1144	bool FoundByHeaderMap = !IsMapped ? false : *IsMapped;
1145	if (!Includers.empty())
1146	diagnoseFrameworkInclude(Diags, IncludeLoc,
1147	Includer: Includers.front().second.getName(), IncludeFilename: Filename,
1148	IncludeFE: *File, isAngled, FoundByHeaderMap);
1149
1150	// Remember this location for the next lookup we do.
1151	cacheLookupSuccess(CacheLookup, HitIt: It, Loc: IncludeLoc);
1152	return File;
1153	}
1154
1155	// If we are including a file with a quoted include "foo.h" from inside
1156	// a header in a framework that is currently being built, and we couldn't
1157	// resolve "foo.h" any other way, change the include to <Foo/foo.h>, where
1158	// "Foo" is the name of the framework in which the including header was found.
1159	if (!Includers.empty() && Includers.front().first && !isAngled &&
1160	!Filename.contains(C: '/')) {
1161	const HeaderFileInfo *IncludingHFI =
1162	getExistingFileInfo(FE: *Includers.front().first);
1163	assert(IncludingHFI && "includer without file info");
1164	if (IncludingHFI->IndexHeaderMapHeader) {
1165	SmallString<128> ScratchFilename;
1166	ScratchFilename += IncludingHFI->Framework;
1167	ScratchFilename += '/';
1168	ScratchFilename += Filename;
1169
1170	OptionalFileEntryRef File = LookupFile(
1171	Filename: ScratchFilename, IncludeLoc, /*isAngled=*/true, FromDir, CurDirArg: &CurDir,
1172	Includers: Includers.front(), SearchPath, RelativePath, RequestingModule,
1173	SuggestedModule, IsMapped, /*IsFrameworkFound=*/nullptr);
1174
1175	if (checkMSVCHeaderSearch(Diags, MSFE,
1176	FE: File ? &File->getFileEntry() : nullptr,
1177	IncludeLoc)) {
1178	if (SuggestedModule)
1179	*SuggestedModule = MSSuggestedModule;
1180	return MSFE;
1181	}
1182
1183	cacheLookupSuccess(CacheLookup&: LookupFileCache[Filename],
1184	HitIt: LookupFileCache[ScratchFilename].HitIt, Loc: IncludeLoc);
1185	// FIXME: SuggestedModule.
1186	return File;
1187	}
1188	}
1189
1190	if (checkMSVCHeaderSearch(Diags, MSFE, FE: nullptr, IncludeLoc)) {
1191	if (SuggestedModule)
1192	*SuggestedModule = MSSuggestedModule;
1193	return MSFE;
1194	}
1195
1196	// Otherwise, didn't find it. Remember we didn't find this.
1197	CacheLookup.HitIt = search_dir_end();
1198	return std::nullopt;
1199	}
1200
1201	/// LookupSubframeworkHeader - Look up a subframework for the specified
1202	/// \#include file. For example, if \#include'ing <HIToolbox/HIToolbox.h> from
1203	/// within ".../Carbon.framework/Headers/Carbon.h", check to see if HIToolbox
1204	/// is a subframework within Carbon.framework. If so, return the FileEntry
1205	/// for the designated file, otherwise return null.
1206	OptionalFileEntryRef HeaderSearch::LookupSubframeworkHeader(
1207	StringRef Filename, FileEntryRef ContextFileEnt,
1208	SmallVectorImpl<char> *SearchPath, SmallVectorImpl<char> *RelativePath,
1209	Module *RequestingModule, ModuleMap::KnownHeader *SuggestedModule) {
1210	// Framework names must have a '/' in the filename. Find it.
1211	// FIXME: Should we permit '\' on Windows?
1212	size_t SlashPos = Filename.find(C: '/');
1213	if (SlashPos == StringRef::npos)
1214	return std::nullopt;
1215
1216	// Look up the base framework name of the ContextFileEnt.
1217	StringRef ContextName = ContextFileEnt.getName();
1218
1219	// If the context info wasn't a framework, couldn't be a subframework.
1220	const unsigned DotFrameworkLen = 10;
1221	auto FrameworkPos = ContextName.find(Str: ".framework");
1222	if (FrameworkPos == StringRef::npos ||
1223	(ContextName[FrameworkPos + DotFrameworkLen] != '/' &&
1224	ContextName[FrameworkPos + DotFrameworkLen] != '\\'))
1225	return std::nullopt;
1226
1227	SmallString<1024> FrameworkName(ContextName.data(), ContextName.data() +
1228	FrameworkPos +
1229	DotFrameworkLen + 1);
1230
1231	// Append Frameworks/HIToolbox.framework/
1232	FrameworkName += "Frameworks/";
1233	FrameworkName.append(in_start: Filename.begin(), in_end: Filename.begin()+SlashPos);
1234	FrameworkName += ".framework/";
1235
1236	auto &CacheLookup =
1237	*FrameworkMap.insert(KV: std::make_pair(x: Filename.substr(Start: 0, N: SlashPos),
1238	y: FrameworkCacheEntry())).first;
1239
1240	// Some other location?
1241	if (CacheLookup.second.Directory &&
1242	CacheLookup.first().size() == FrameworkName.size() &&
1243	memcmp(s1: CacheLookup.first().data(), s2: &FrameworkName[0],
1244	n: CacheLookup.first().size()) != 0)
1245	return std::nullopt;
1246
1247	// Cache subframework.
1248	if (!CacheLookup.second.Directory) {
1249	++NumSubFrameworkLookups;
1250
1251	// If the framework dir doesn't exist, we fail.
1252	auto Dir = FileMgr.getOptionalDirectoryRef(DirName: FrameworkName);
1253	if (!Dir)
1254	return std::nullopt;
1255
1256	// Otherwise, if it does, remember that this is the right direntry for this
1257	// framework.
1258	CacheLookup.second.Directory = Dir;
1259	}
1260
1261
1262	if (RelativePath) {
1263	RelativePath->clear();
1264	RelativePath->append(in_start: Filename.begin()+SlashPos+1, in_end: Filename.end());
1265	}
1266
1267	// Check ".../Frameworks/HIToolbox.framework/Headers/HIToolbox.h"
1268	SmallString<1024> HeadersFilename(FrameworkName);
1269	HeadersFilename += "Headers/";
1270	if (SearchPath) {
1271	SearchPath->clear();
1272	// Without trailing '/'.
1273	SearchPath->append(in_start: HeadersFilename.begin(), in_end: HeadersFilename.end()-1);
1274	}
1275
1276	HeadersFilename.append(in_start: Filename.begin()+SlashPos+1, in_end: Filename.end());
1277	auto File = FileMgr.getOptionalFileRef(Filename: HeadersFilename, /*OpenFile=*/true);
1278	if (!File) {
1279	// Check ".../Frameworks/HIToolbox.framework/PrivateHeaders/HIToolbox.h"
1280	HeadersFilename = FrameworkName;
1281	HeadersFilename += "PrivateHeaders/";
1282	if (SearchPath) {
1283	SearchPath->clear();
1284	// Without trailing '/'.
1285	SearchPath->append(in_start: HeadersFilename.begin(), in_end: HeadersFilename.end()-1);
1286	}
1287
1288	HeadersFilename.append(in_start: Filename.begin()+SlashPos+1, in_end: Filename.end());
1289	File = FileMgr.getOptionalFileRef(Filename: HeadersFilename, /*OpenFile=*/true);
1290
1291	if (!File)
1292	return std::nullopt;
1293	}
1294
1295	// This file is a system header or C++ unfriendly if the old file is.
1296	const HeaderFileInfo *ContextHFI = getExistingFileInfo(FE: ContextFileEnt);
1297	assert(ContextHFI && "context file without file info");
1298	// Note that the temporary 'DirInfo' is required here, as the call to
1299	// getFileInfo could resize the vector and might invalidate 'ContextHFI'.
1300	unsigned DirInfo = ContextHFI->DirInfo;
1301	getFileInfo(FE: *File).DirInfo = DirInfo;
1302
1303	FrameworkName.pop_back(); // remove the trailing '/'
1304	if (!findUsableModuleForFrameworkHeader(File: *File, FrameworkName,
1305	RequestingModule, SuggestedModule,
1306	/*IsSystem*/ IsSystemFramework: false))
1307	return std::nullopt;
1308
1309	return *File;
1310	}
1311
1312	//===----------------------------------------------------------------------===//
1313	// File Info Management.
1314	//===----------------------------------------------------------------------===//
1315
1316	static void mergeHeaderFileInfoModuleBits(HeaderFileInfo &HFI,
1317	bool isModuleHeader,
1318	bool isTextualModuleHeader) {
1319	assert((!isModuleHeader || !isTextualModuleHeader) &&
1320	"A header can't build with a module and be textual at the same time");
1321	HFI.isModuleHeader |= isModuleHeader;
1322	if (HFI.isModuleHeader)
1323	HFI.isTextualModuleHeader = false;
1324	else
1325	HFI.isTextualModuleHeader |= isTextualModuleHeader;
1326	}
1327
1328	void HeaderFileInfo::mergeModuleMembership(ModuleMap::ModuleHeaderRole Role) {
1329	mergeHeaderFileInfoModuleBits(HFI&: *this, isModuleHeader: ModuleMap::isModular(Role),
1330	isTextualModuleHeader: (Role & ModuleMap::TextualHeader));
1331	}
1332
1333	/// Merge the header file info provided by \p OtherHFI into the current
1334	/// header file info (\p HFI)
1335	static void mergeHeaderFileInfo(HeaderFileInfo &HFI,
1336	const HeaderFileInfo &OtherHFI) {
1337	assert(OtherHFI.External && "expected to merge external HFI");
1338
1339	HFI.isImport |= OtherHFI.isImport;
1340	HFI.isPragmaOnce |= OtherHFI.isPragmaOnce;
1341	mergeHeaderFileInfoModuleBits(HFI, isModuleHeader: OtherHFI.isModuleHeader,
1342	isTextualModuleHeader: OtherHFI.isTextualModuleHeader);
1343
1344	if (!HFI.ControllingMacro && !HFI.ControllingMacroID) {
1345	HFI.ControllingMacro = OtherHFI.ControllingMacro;
1346	HFI.ControllingMacroID = OtherHFI.ControllingMacroID;
1347	}
1348
1349	HFI.DirInfo = OtherHFI.DirInfo;
1350	HFI.External = (!HFI.IsValid || HFI.External);
1351	HFI.IsValid = true;
1352	HFI.IndexHeaderMapHeader = OtherHFI.IndexHeaderMapHeader;
1353
1354	if (HFI.Framework.empty())
1355	HFI.Framework = OtherHFI.Framework;
1356	}
1357
1358	HeaderFileInfo &HeaderSearch::getFileInfo(FileEntryRef FE) {
1359	if (FE.getUID() >= FileInfo.size())
1360	FileInfo.resize(new_size: FE.getUID() + 1);
1361
1362	HeaderFileInfo *HFI = &FileInfo[FE.getUID()];
1363	// FIXME: Use a generation count to check whether this is really up to date.
1364	if (ExternalSource && !HFI->Resolved) {
1365	auto ExternalHFI = ExternalSource->GetHeaderFileInfo(FE);
1366	if (ExternalHFI.IsValid) {
1367	HFI->Resolved = true;
1368	if (ExternalHFI.External)
1369	mergeHeaderFileInfo(HFI&: *HFI, OtherHFI: ExternalHFI);
1370	}
1371	}
1372
1373	HFI->IsValid = true;
1374	// We assume the caller has local information about this header file, so it's
1375	// no longer strictly external.
1376	HFI->External = false;
1377	return *HFI;
1378	}
1379
1380	const HeaderFileInfo *HeaderSearch::getExistingFileInfo(FileEntryRef FE) const {
1381	HeaderFileInfo *HFI;
1382	if (ExternalSource) {
1383	if (FE.getUID() >= FileInfo.size())
1384	FileInfo.resize(new_size: FE.getUID() + 1);
1385
1386	HFI = &FileInfo[FE.getUID()];
1387	// FIXME: Use a generation count to check whether this is really up to date.
1388	if (!HFI->Resolved) {
1389	auto ExternalHFI = ExternalSource->GetHeaderFileInfo(FE);
1390	if (ExternalHFI.IsValid) {
1391	HFI->Resolved = true;
1392	if (ExternalHFI.External)
1393	mergeHeaderFileInfo(HFI&: *HFI, OtherHFI: ExternalHFI);
1394	}
1395	}
1396	} else if (FE.getUID() < FileInfo.size()) {
1397	HFI = &FileInfo[FE.getUID()];
1398	} else {
1399	HFI = nullptr;
1400	}
1401
1402	return (HFI && HFI->IsValid) ? HFI : nullptr;
1403	}
1404
1405	const HeaderFileInfo *
1406	HeaderSearch::getExistingLocalFileInfo(FileEntryRef FE) const {
1407	HeaderFileInfo *HFI;
1408	if (FE.getUID() < FileInfo.size()) {
1409	HFI = &FileInfo[FE.getUID()];
1410	} else {
1411	HFI = nullptr;
1412	}
1413
1414	return (HFI && HFI->IsValid && !HFI->External) ? HFI : nullptr;
1415	}
1416
1417	bool HeaderSearch::isFileMultipleIncludeGuarded(FileEntryRef File) const {
1418	// Check if we've entered this file and found an include guard or #pragma
1419	// once. Note that we dor't check for #import, because that's not a property
1420	// of the file itself.
1421	if (auto *HFI = getExistingFileInfo(FE: File))
1422	return HFI->isPragmaOnce || HFI->ControllingMacro ||
1423	HFI->ControllingMacroID;
1424	return false;
1425	}
1426
1427	void HeaderSearch::MarkFileModuleHeader(FileEntryRef FE,
1428	ModuleMap::ModuleHeaderRole Role,
1429	bool isCompilingModuleHeader) {
1430	// Don't mark the file info as non-external if there's nothing to change.
1431	if (!isCompilingModuleHeader) {
1432	if ((Role & ModuleMap::ExcludedHeader))
1433	return;
1434	auto *HFI = getExistingFileInfo(FE);
1435	if (HFI && HFI->isModuleHeader)
1436	return;
1437	}
1438
1439	auto &HFI = getFileInfo(FE);
1440	HFI.mergeModuleMembership(Role);
1441	HFI.isCompilingModuleHeader |= isCompilingModuleHeader;
1442	}
1443
1444	bool HeaderSearch::ShouldEnterIncludeFile(Preprocessor &PP,
1445	FileEntryRef File, bool isImport,
1446	bool ModulesEnabled, Module *M,
1447	bool &IsFirstIncludeOfFile) {
1448	// An include file should be entered if either:
1449	// 1. This is the first include of the file.
1450	// 2. This file can be included multiple times, that is it's not an
1451	// "include-once" file.
1452	//
1453	// Include-once is controlled by these preprocessor directives.
1454	//
1455	// #pragma once
1456	// This directive is in the include file, and marks it as an include-once
1457	// file.
1458	//
1459	// #import <file>
1460	// This directive is in the includer, and indicates that the include file
1461	// should only be entered if this is the first include.
1462	++NumIncluded;
1463	IsFirstIncludeOfFile = false;
1464	HeaderFileInfo &FileInfo = getFileInfo(FE: File);
1465
1466	auto MaybeReenterImportedFile = [&]() -> bool {
1467	// Modules add a wrinkle though: what's included isn't necessarily visible.
1468	// Consider this module.
1469	// module Example {
1470	// module A { header "a.h" export * }
1471	// module B { header "b.h" export * }
1472	// }
1473	// b.h includes c.h. The main file includes a.h, which will trigger a module
1474	// build of Example, and c.h will be included. However, c.h isn't visible to
1475	// the main file. Normally this is fine, the main file can just include c.h
1476	// if it needs it. If c.h is in a module, the include will translate into a
1477	// module import, this function will be skipped, and everything will work as
1478	// expected. However, if c.h is not in a module (or is `textual`), then this
1479	// function will run. If c.h is include-once, it will not be entered from
1480	// the main file and it will still not be visible.
1481
1482	// If modules aren't enabled then there's no visibility issue. Always
1483	// respect `#pragma once`.
1484	if (!ModulesEnabled || FileInfo.isPragmaOnce)
1485	return false;
1486
1487	// Ensure FileInfo bits are up to date.
1488	ModMap.resolveHeaderDirectives(File);
1489
1490	// This brings up a subtlety of #import - it's not a very good indicator of
1491	// include-once. Developers are often unaware of the difference between
1492	// #include and #import, and tend to use one or the other indiscrimiately.
1493	// In order to support #include on include-once headers that lack macro
1494	// guards and `#pragma once` (which is the vast majority of Objective-C
1495	// headers), if a file is ever included with #import, it's marked as
1496	// isImport in the HeaderFileInfo and treated as include-once. This allows
1497	// #include to work in Objective-C.
1498	// #include <Foundation/Foundation.h>
1499	// #include <Foundation/NSString.h>
1500	// Foundation.h has an #import of NSString.h, and so the second #include is
1501	// skipped even though NSString.h has no `#pragma once` and no macro guard.
1502	//
1503	// However, this helpfulness causes problems with modules. If c.h is not an
1504	// include-once file, but something included it with #import anyway (as is
1505	// typical in Objective-C code), this include will be skipped and c.h will
1506	// not be visible. Consider it not include-once if it is a `textual` header
1507	// in a module.
1508	if (FileInfo.isTextualModuleHeader)
1509	return true;
1510
1511	if (FileInfo.isCompilingModuleHeader) {
1512	// It's safer to re-enter a file whose module is being built because its
1513	// declarations will still be scoped to a single module.
1514	if (FileInfo.isModuleHeader) {
1515	// Headers marked as "builtin" are covered by the system module maps
1516	// rather than the builtin ones. Some versions of the Darwin module fail
1517	// to mark stdarg.h and stddef.h as textual. Attempt to re-enter these
1518	// files while building their module to allow them to function properly.
1519	if (ModMap.isBuiltinHeader(File))
1520	return true;
1521	} else {
1522	// Files that are excluded from their module can potentially be
1523	// re-entered from their own module. This might cause redeclaration
1524	// errors if another module saw this file first, but there's a
1525	// reasonable chance that its module will build first. However if
1526	// there's no controlling macro, then trust the #import and assume this
1527	// really is an include-once file.
1528	if (FileInfo.getControllingMacro(External: ExternalLookup))
1529	return true;
1530	}
1531	}
1532	// If the include file has a macro guard, then it might still not be
1533	// re-entered if the controlling macro is visibly defined. e.g. another
1534	// header in the module being built included this file and local submodule
1535	// visibility is not enabled.
1536
1537	// It might be tempting to re-enter the include-once file if it's not
1538	// visible in an attempt to make it visible. However this will still cause
1539	// redeclaration errors against the known-but-not-visible declarations. The
1540	// include file not being visible will most likely cause "undefined x"
1541	// errors, but at least there's a slim chance of compilation succeeding.
1542	return false;
1543	};
1544
1545	if (isImport) {
1546	// As discussed above, record that this file was ever `#import`ed, and treat
1547	// it as an include-once file from here out.
1548	FileInfo.isImport = true;
1549	if (PP.alreadyIncluded(File) && !MaybeReenterImportedFile())
1550	return false;
1551	} else {
1552	// isPragmaOnce and isImport are only set after the file has been included
1553	// at least once. If either are set then this is a repeat #include of an
1554	// include-once file.
1555	if (FileInfo.isPragmaOnce ||
1556	(FileInfo.isImport && !MaybeReenterImportedFile()))
1557	return false;
1558	}
1559
1560	// As a final optimization, check for a macro guard and skip entering the file
1561	// if the controlling macro is defined. The macro guard will effectively erase
1562	// the file's contents, and the include would have no effect other than to
1563	// waste time opening and reading a file.
1564	if (const IdentifierInfo *ControllingMacro =
1565	FileInfo.getControllingMacro(External: ExternalLookup)) {
1566	// If the header corresponds to a module, check whether the macro is already
1567	// defined in that module rather than checking all visible modules. This is
1568	// mainly to cover corner cases where the same controlling macro is used in
1569	// different files in multiple modules.
1570	if (M ? PP.isMacroDefinedInLocalModule(II: ControllingMacro, M)
1571	: PP.isMacroDefined(II: ControllingMacro)) {
1572	++NumMultiIncludeFileOptzn;
1573	return false;
1574	}
1575	}
1576
1577	FileInfo.IsLocallyIncluded = true;
1578	IsFirstIncludeOfFile = PP.markIncluded(File);
1579	return true;
1580	}
1581
1582	size_t HeaderSearch::getTotalMemory() const {
1583	return SearchDirs.capacity()
1584	+ llvm::capacity_in_bytes(x: FileInfo)
1585	+ llvm::capacity_in_bytes(x: HeaderMaps)
1586	+ LookupFileCache.getAllocator().getTotalMemory()
1587	+ FrameworkMap.getAllocator().getTotalMemory();
1588	}
1589
1590	unsigned HeaderSearch::searchDirIdx(const DirectoryLookup &DL) const {
1591	return &DL - &*SearchDirs.begin();
1592	}
1593
1594	StringRef HeaderSearch::getUniqueFrameworkName(StringRef Framework) {
1595	return FrameworkNames.insert(key: Framework).first->first();
1596	}
1597
1598	StringRef HeaderSearch::getIncludeNameForHeader(const FileEntry *File) const {
1599	auto It = IncludeNames.find(Val: File);
1600	if (It == IncludeNames.end())
1601	return {};
1602	return It->second;
1603	}
1604
1605	bool HeaderSearch::hasModuleMap(StringRef FileName,
1606	const DirectoryEntry *Root,
1607	bool IsSystem) {
1608	if (!HSOpts->ImplicitModuleMaps)
1609	return false;
1610
1611	SmallVector<const DirectoryEntry *, 2> FixUpDirectories;
1612
1613	StringRef DirName = FileName;
1614	do {
1615	// Get the parent directory name.
1616	DirName = llvm::sys::path::parent_path(path: DirName);
1617	if (DirName.empty())
1618	return false;
1619
1620	// Determine whether this directory exists.
1621	auto Dir = FileMgr.getOptionalDirectoryRef(DirName);
1622	if (!Dir)
1623	return false;
1624
1625	// Try to load the module map file in this directory.
1626	switch (loadModuleMapFile(Dir: *Dir, IsSystem,
1627	IsFramework: llvm::sys::path::extension(path: Dir->getName()) ==
1628	".framework")) {
1629	case LMM_NewlyLoaded:
1630	case LMM_AlreadyLoaded:
1631	// Success. All of the directories we stepped through inherit this module
1632	// map file.
1633	for (unsigned I = 0, N = FixUpDirectories.size(); I != N; ++I)
1634	DirectoryHasModuleMap[FixUpDirectories[I]] = true;
1635	return true;
1636
1637	case LMM_NoDirectory:
1638	case LMM_InvalidModuleMap:
1639	break;
1640	}
1641
1642	// If we hit the top of our search, we're done.
1643	if (*Dir == Root)
1644	return false;
1645
1646	// Keep track of all of the directories we checked, so we can mark them as
1647	// having module maps if we eventually do find a module map.
1648	FixUpDirectories.push_back(Elt: *Dir);
1649	} while (true);
1650	}
1651
1652	ModuleMap::KnownHeader
1653	HeaderSearch::findModuleForHeader(FileEntryRef File, bool AllowTextual,
1654	bool AllowExcluded) const {
1655	if (ExternalSource) {
1656	// Make sure the external source has handled header info about this file,
1657	// which includes whether the file is part of a module.
1658	(void)getExistingFileInfo(FE: File);
1659	}
1660	return ModMap.findModuleForHeader(File, AllowTextual, AllowExcluded);
1661	}
1662
1663	ArrayRef<ModuleMap::KnownHeader>
1664	HeaderSearch::findAllModulesForHeader(FileEntryRef File) const {
1665	if (ExternalSource) {
1666	// Make sure the external source has handled header info about this file,
1667	// which includes whether the file is part of a module.
1668	(void)getExistingFileInfo(FE: File);
1669	}
1670	return ModMap.findAllModulesForHeader(File);
1671	}
1672
1673	ArrayRef<ModuleMap::KnownHeader>
1674	HeaderSearch::findResolvedModulesForHeader(FileEntryRef File) const {
1675	if (ExternalSource) {
1676	// Make sure the external source has handled header info about this file,
1677	// which includes whether the file is part of a module.
1678	(void)getExistingFileInfo(FE: File);
1679	}
1680	return ModMap.findResolvedModulesForHeader(File);
1681	}
1682
1683	static bool suggestModule(HeaderSearch &HS, FileEntryRef File,
1684	Module *RequestingModule,
1685	ModuleMap::KnownHeader *SuggestedModule) {
1686	ModuleMap::KnownHeader Module =
1687	HS.findModuleForHeader(File, /*AllowTextual*/true);
1688
1689	// If this module specifies [no_undeclared_includes], we cannot find any
1690	// file that's in a non-dependency module.
1691	if (RequestingModule && Module && RequestingModule->NoUndeclaredIncludes) {
1692	HS.getModuleMap().resolveUses(Mod: RequestingModule, /*Complain*/ false);
1693	if (!RequestingModule->directlyUses(Requested: Module.getModule())) {
1694	// Builtin headers are a special case. Multiple modules can use the same
1695	// builtin as a modular header (see also comment in
1696	// ShouldEnterIncludeFile()), so the builtin header may have been
1697	// "claimed" by an unrelated module. This shouldn't prevent us from
1698	// including the builtin header textually in this module.
1699	if (HS.getModuleMap().isBuiltinHeader(File)) {
1700	if (SuggestedModule)
1701	*SuggestedModule = ModuleMap::KnownHeader();
1702	return true;
1703	}
1704	// TODO: Add this module (or just its module map file) into something like
1705	// `RequestingModule->AffectingClangModules`.
1706	return false;
1707	}
1708	}
1709
1710	if (SuggestedModule)
1711	*SuggestedModule = (Module.getRole() & ModuleMap::TextualHeader)
1712	? ModuleMap::KnownHeader()
1713	: Module;
1714
1715	return true;
1716	}
1717
1718	bool HeaderSearch::findUsableModuleForHeader(
1719	FileEntryRef File, const DirectoryEntry *Root, Module *RequestingModule,
1720	ModuleMap::KnownHeader *SuggestedModule, bool IsSystemHeaderDir) {
1721	if (needModuleLookup(RequestingModule, HasSuggestedModule: SuggestedModule)) {
1722	// If there is a module that corresponds to this header, suggest it.
1723	hasModuleMap(FileName: File.getNameAsRequested(), Root, IsSystem: IsSystemHeaderDir);
1724	return suggestModule(HS&: *this, File, RequestingModule, SuggestedModule);
1725	}
1726	return true;
1727	}
1728
1729	bool HeaderSearch::findUsableModuleForFrameworkHeader(
1730	FileEntryRef File, StringRef FrameworkName, Module *RequestingModule,
1731	ModuleMap::KnownHeader *SuggestedModule, bool IsSystemFramework) {
1732	// If we're supposed to suggest a module, look for one now.
1733	if (needModuleLookup(RequestingModule, HasSuggestedModule: SuggestedModule)) {
1734	// Find the top-level framework based on this framework.
1735	SmallVector<std::string, 4> SubmodulePath;
1736	OptionalDirectoryEntryRef TopFrameworkDir =
1737	::getTopFrameworkDir(FileMgr, DirName: FrameworkName, SubmodulePath);
1738	assert(TopFrameworkDir && "Could not find the top-most framework dir");
1739
1740	// Determine the name of the top-level framework.
1741	StringRef ModuleName = llvm::sys::path::stem(path: TopFrameworkDir->getName());
1742
1743	// Load this framework module. If that succeeds, find the suggested module
1744	// for this header, if any.
1745	loadFrameworkModule(Name: ModuleName, Dir: *TopFrameworkDir, IsSystem: IsSystemFramework);
1746
1747	// FIXME: This can find a module not part of ModuleName, which is
1748	// important so that we're consistent about whether this header
1749	// corresponds to a module. Possibly we should lock down framework modules
1750	// so that this is not possible.
1751	return suggestModule(HS&: *this, File, RequestingModule, SuggestedModule);
1752	}
1753	return true;
1754	}
1755
1756	static OptionalFileEntryRef getPrivateModuleMap(FileEntryRef File,
1757	FileManager &FileMgr,
1758	DiagnosticsEngine &Diags) {
1759	StringRef Filename = llvm::sys::path::filename(path: File.getName());
1760	SmallString<128> PrivateFilename(File.getDir().getName());
1761	if (Filename == "module.map")
1762	llvm::sys::path::append(path&: PrivateFilename, a: "module_private.map");
1763	else if (Filename == "module.modulemap")
1764	llvm::sys::path::append(path&: PrivateFilename, a: "module.private.modulemap");
1765	else
1766	return std::nullopt;
1767	auto PMMFile = FileMgr.getOptionalFileRef(Filename: PrivateFilename);
1768	if (PMMFile) {
1769	if (Filename == "module.map")
1770	Diags.Report(diag::warn_deprecated_module_dot_map)
1771	<< PrivateFilename << 1
1772	<< File.getDir().getName().ends_with(Suffix: ".framework");
1773	}
1774	return PMMFile;
1775	}
1776
1777	bool HeaderSearch::loadModuleMapFile(FileEntryRef File, bool IsSystem,
1778	FileID ID, unsigned *Offset,
1779	StringRef OriginalModuleMapFile) {
1780	// Find the directory for the module. For frameworks, that may require going
1781	// up from the 'Modules' directory.
1782	OptionalDirectoryEntryRef Dir;
1783	if (getHeaderSearchOpts().ModuleMapFileHomeIsCwd) {
1784	Dir = FileMgr.getOptionalDirectoryRef(DirName: ".");
1785	} else {
1786	if (!OriginalModuleMapFile.empty()) {
1787	// We're building a preprocessed module map. Find or invent the directory
1788	// that it originally occupied.
1789	Dir = FileMgr.getOptionalDirectoryRef(
1790	DirName: llvm::sys::path::parent_path(path: OriginalModuleMapFile));
1791	if (!Dir) {
1792	auto FakeFile = FileMgr.getVirtualFileRef(Filename: OriginalModuleMapFile, Size: 0, ModificationTime: 0);
1793	Dir = FakeFile.getDir();
1794	}
1795	} else {
1796	Dir = File.getDir();
1797	}
1798
1799	assert(Dir && "parent must exist");
1800	StringRef DirName(Dir->getName());
1801	if (llvm::sys::path::filename(path: DirName) == "Modules") {
1802	DirName = llvm::sys::path::parent_path(path: DirName);
1803	if (DirName.ends_with(Suffix: ".framework"))
1804	if (auto MaybeDir = FileMgr.getOptionalDirectoryRef(DirName))
1805	Dir = *MaybeDir;
1806	// FIXME: This assert can fail if there's a race between the above check
1807	// and the removal of the directory.
1808	assert(Dir && "parent must exist");
1809	}
1810	}
1811
1812	assert(Dir && "module map home directory must exist");
1813	switch (loadModuleMapFileImpl(File, IsSystem, Dir: *Dir, ID, Offset)) {
1814	case LMM_AlreadyLoaded:
1815	case LMM_NewlyLoaded:
1816	return false;
1817	case LMM_NoDirectory:
1818	case LMM_InvalidModuleMap:
1819	return true;
1820	}
1821	llvm_unreachable("Unknown load module map result");
1822	}
1823
1824	HeaderSearch::LoadModuleMapResult
1825	HeaderSearch::loadModuleMapFileImpl(FileEntryRef File, bool IsSystem,
1826	DirectoryEntryRef Dir, FileID ID,
1827	unsigned *Offset) {
1828	// Check whether we've already loaded this module map, and mark it as being
1829	// loaded in case we recursively try to load it from itself.
1830	auto AddResult = LoadedModuleMaps.insert(KV: std::make_pair(x&: File, y: true));
1831	if (!AddResult.second)
1832	return AddResult.first->second ? LMM_AlreadyLoaded : LMM_InvalidModuleMap;
1833
1834	if (ModMap.parseModuleMapFile(File, IsSystem, HomeDir: Dir, ID, Offset)) {
1835	LoadedModuleMaps[File] = false;
1836	return LMM_InvalidModuleMap;
1837	}
1838
1839	// Try to load a corresponding private module map.
1840	if (OptionalFileEntryRef PMMFile =
1841	getPrivateModuleMap(File, FileMgr, Diags)) {
1842	if (ModMap.parseModuleMapFile(File: *PMMFile, IsSystem, HomeDir: Dir)) {
1843	LoadedModuleMaps[File] = false;
1844	return LMM_InvalidModuleMap;
1845	}
1846	}
1847
1848	// This directory has a module map.
1849	return LMM_NewlyLoaded;
1850	}
1851
1852	OptionalFileEntryRef
1853	HeaderSearch::lookupModuleMapFile(DirectoryEntryRef Dir, bool IsFramework) {
1854	if (!HSOpts->ImplicitModuleMaps)
1855	return std::nullopt;
1856	// For frameworks, the preferred spelling is Modules/module.modulemap, but
1857	// module.map at the framework root is also accepted.
1858	SmallString<128> ModuleMapFileName(Dir.getName());
1859	if (IsFramework)
1860	llvm::sys::path::append(path&: ModuleMapFileName, a: "Modules");
1861	llvm::sys::path::append(path&: ModuleMapFileName, a: "module.modulemap");
1862	if (auto F = FileMgr.getOptionalFileRef(Filename: ModuleMapFileName))
1863	return *F;
1864
1865	// Continue to allow module.map, but warn it's deprecated.
1866	ModuleMapFileName = Dir.getName();
1867	llvm::sys::path::append(path&: ModuleMapFileName, a: "module.map");
1868	if (auto F = FileMgr.getOptionalFileRef(Filename: ModuleMapFileName)) {
1869	Diags.Report(diag::warn_deprecated_module_dot_map)
1870	<< ModuleMapFileName << 0 << IsFramework;
1871	return *F;
1872	}
1873
1874	// For frameworks, allow to have a private module map with a preferred
1875	// spelling when a public module map is absent.
1876	if (IsFramework) {
1877	ModuleMapFileName = Dir.getName();
1878	llvm::sys::path::append(path&: ModuleMapFileName, a: "Modules",
1879	b: "module.private.modulemap");
1880	if (auto F = FileMgr.getOptionalFileRef(Filename: ModuleMapFileName))
1881	return *F;
1882	}
1883	return std::nullopt;
1884	}
1885
1886	Module *HeaderSearch::loadFrameworkModule(StringRef Name, DirectoryEntryRef Dir,
1887	bool IsSystem) {
1888	// Try to load a module map file.
1889	switch (loadModuleMapFile(Dir, IsSystem, /*IsFramework*/true)) {
1890	case LMM_InvalidModuleMap:
1891	// Try to infer a module map from the framework directory.
1892	if (HSOpts->ImplicitModuleMaps)
1893	ModMap.inferFrameworkModule(FrameworkDir: Dir, IsSystem, /*Parent=*/nullptr);
1894	break;
1895
1896	case LMM_NoDirectory:
1897	return nullptr;
1898
1899	case LMM_AlreadyLoaded:
1900	case LMM_NewlyLoaded:
1901	break;
1902	}
1903
1904	return ModMap.findModule(Name);
1905	}
1906
1907	HeaderSearch::LoadModuleMapResult
1908	HeaderSearch::loadModuleMapFile(StringRef DirName, bool IsSystem,
1909	bool IsFramework) {
1910	if (auto Dir = FileMgr.getOptionalDirectoryRef(DirName))
1911	return loadModuleMapFile(Dir: *Dir, IsSystem, IsFramework);
1912
1913	return LMM_NoDirectory;
1914	}
1915
1916	HeaderSearch::LoadModuleMapResult
1917	HeaderSearch::loadModuleMapFile(DirectoryEntryRef Dir, bool IsSystem,
1918	bool IsFramework) {
1919	auto KnownDir = DirectoryHasModuleMap.find(Val: Dir);
1920	if (KnownDir != DirectoryHasModuleMap.end())
1921	return KnownDir->second ? LMM_AlreadyLoaded : LMM_InvalidModuleMap;
1922
1923	if (OptionalFileEntryRef ModuleMapFile =
1924	lookupModuleMapFile(Dir, IsFramework)) {
1925	LoadModuleMapResult Result =
1926	loadModuleMapFileImpl(File: *ModuleMapFile, IsSystem, Dir);
1927	// Add Dir explicitly in case ModuleMapFile is in a subdirectory.
1928	// E.g. Foo.framework/Modules/module.modulemap
1929	// ^Dir ^ModuleMapFile
1930	if (Result == LMM_NewlyLoaded)
1931	DirectoryHasModuleMap[Dir] = true;
1932	else if (Result == LMM_InvalidModuleMap)
1933	DirectoryHasModuleMap[Dir] = false;
1934	return Result;
1935	}
1936	return LMM_InvalidModuleMap;
1937	}
1938
1939	void HeaderSearch::collectAllModules(SmallVectorImpl<Module *> &Modules) {
1940	Modules.clear();
1941
1942	if (HSOpts->ImplicitModuleMaps) {
1943	// Load module maps for each of the header search directories.
1944	for (DirectoryLookup &DL : search_dir_range()) {
1945	bool IsSystem = DL.isSystemHeaderDirectory();
1946	if (DL.isFramework()) {
1947	std::error_code EC;
1948	SmallString<128> DirNative;
1949	llvm::sys::path::native(path: DL.getFrameworkDirRef()->getName(), result&: DirNative);
1950
1951	// Search each of the ".framework" directories to load them as modules.
1952	llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
1953	for (llvm::vfs::directory_iterator Dir = FS.dir_begin(Dir: DirNative, EC),
1954	DirEnd;
1955	Dir != DirEnd && !EC; Dir.increment(EC)) {
1956	if (llvm::sys::path::extension(path: Dir->path()) != ".framework")
1957	continue;
1958
1959	auto FrameworkDir = FileMgr.getOptionalDirectoryRef(DirName: Dir->path());
1960	if (!FrameworkDir)
1961	continue;
1962
1963	// Load this framework module.
1964	loadFrameworkModule(Name: llvm::sys::path::stem(path: Dir->path()), Dir: *FrameworkDir,
1965	IsSystem);
1966	}
1967	continue;
1968	}
1969
1970	// FIXME: Deal with header maps.
1971	if (DL.isHeaderMap())
1972	continue;
1973
1974	// Try to load a module map file for the search directory.
1975	loadModuleMapFile(Dir: *DL.getDirRef(), IsSystem, /*IsFramework*/ false);
1976
1977	// Try to load module map files for immediate subdirectories of this
1978	// search directory.
1979	loadSubdirectoryModuleMaps(SearchDir&: DL);
1980	}
1981	}
1982
1983	// Populate the list of modules.
1984	llvm::transform(Range: ModMap.modules(), d_first: std::back_inserter(x&: Modules),
1985	F: [](const auto &NameAndMod) { return NameAndMod.second; });
1986	}
1987
1988	void HeaderSearch::loadTopLevelSystemModules() {
1989	if (!HSOpts->ImplicitModuleMaps)
1990	return;
1991
1992	// Load module maps for each of the header search directories.
1993	for (const DirectoryLookup &DL : search_dir_range()) {
1994	// We only care about normal header directories.
1995	if (!DL.isNormalDir())
1996	continue;
1997
1998	// Try to load a module map file for the search directory.
1999	loadModuleMapFile(Dir: *DL.getDirRef(), IsSystem: DL.isSystemHeaderDirectory(),
2000	IsFramework: DL.isFramework());
2001	}
2002	}
2003
2004	void HeaderSearch::loadSubdirectoryModuleMaps(DirectoryLookup &SearchDir) {
2005	assert(HSOpts->ImplicitModuleMaps &&
2006	"Should not be loading subdirectory module maps");
2007
2008	if (SearchDir.haveSearchedAllModuleMaps())
2009	return;
2010
2011	std::error_code EC;
2012	SmallString<128> Dir = SearchDir.getDirRef()->getName();
2013	FileMgr.makeAbsolutePath(Path&: Dir);
2014	SmallString<128> DirNative;
2015	llvm::sys::path::native(path: Dir, result&: DirNative);
2016	llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
2017	for (llvm::vfs::directory_iterator Dir = FS.dir_begin(Dir: DirNative, EC), DirEnd;
2018	Dir != DirEnd && !EC; Dir.increment(EC)) {
2019	if (Dir->type() == llvm::sys::fs::file_type::regular_file)
2020	continue;
2021	bool IsFramework = llvm::sys::path::extension(path: Dir->path()) == ".framework";
2022	if (IsFramework == SearchDir.isFramework())
2023	loadModuleMapFile(DirName: Dir->path(), IsSystem: SearchDir.isSystemHeaderDirectory(),
2024	IsFramework: SearchDir.isFramework());
2025	}
2026
2027	SearchDir.setSearchedAllModuleMaps(true);
2028	}
2029
2030	std::string HeaderSearch::suggestPathToFileForDiagnostics(
2031	FileEntryRef File, llvm::StringRef MainFile, bool *IsAngled) const {
2032	return suggestPathToFileForDiagnostics(File: File.getName(), /*WorkingDir=*/"",
2033	MainFile, IsAngled);
2034	}
2035
2036	std::string HeaderSearch::suggestPathToFileForDiagnostics(
2037	llvm::StringRef File, llvm::StringRef WorkingDir, llvm::StringRef MainFile,
2038	bool *IsAngled) const {
2039	using namespace llvm::sys;
2040
2041	llvm::SmallString<32> FilePath = File;
2042	// remove_dots switches to backslashes on windows as a side-effect!
2043	// We always want to suggest forward slashes for includes.
2044	// (not remove_dots(..., posix) as that misparses windows paths).
2045	path::remove_dots(path&: FilePath, /*remove_dot_dot=*/true);
2046	path::native(path&: FilePath, style: path::Style::posix);
2047	File = FilePath;
2048
2049	unsigned BestPrefixLength = 0;
2050	// Checks whether `Dir` is a strict path prefix of `File`. If so and that's
2051	// the longest prefix we've seen so for it, returns true and updates the
2052	// `BestPrefixLength` accordingly.
2053	auto CheckDir = [&](llvm::SmallString<32> Dir) -> bool {
2054	if (!WorkingDir.empty() && !path::is_absolute(path: Dir))
2055	fs::make_absolute(current_directory: WorkingDir, path&: Dir);
2056	path::remove_dots(path&: Dir, /*remove_dot_dot=*/true);
2057	for (auto NI = path::begin(path: File), NE = path::end(path: File),
2058	DI = path::begin(path: Dir), DE = path::end(path: Dir);
2059	NI != NE; ++NI, ++DI) {
2060	if (DI == DE) {
2061	// Dir is a prefix of File, up to choice of path separators.
2062	unsigned PrefixLength = NI - path::begin(path: File);
2063	if (PrefixLength > BestPrefixLength) {
2064	BestPrefixLength = PrefixLength;
2065	return true;
2066	}
2067	break;
2068	}
2069
2070	// Consider all path separators equal.
2071	if (NI->size() == 1 && DI->size() == 1 &&
2072	path::is_separator(value: NI->front()) && path::is_separator(value: DI->front()))
2073	continue;
2074
2075	// Special case Apple .sdk folders since the search path is typically a
2076	// symlink like `iPhoneSimulator14.5.sdk` while the file is instead
2077	// located in `iPhoneSimulator.sdk` (the real folder).
2078	if (NI->ends_with(Suffix: ".sdk") && DI->ends_with(Suffix: ".sdk")) {
2079	StringRef NBasename = path::stem(path: *NI);
2080	StringRef DBasename = path::stem(path: *DI);
2081	if (DBasename.starts_with(Prefix: NBasename))
2082	continue;
2083	}
2084
2085	if (*NI != *DI)
2086	break;
2087	}
2088	return false;
2089	};
2090
2091	bool BestPrefixIsFramework = false;
2092	for (const DirectoryLookup &DL : search_dir_range()) {
2093	if (DL.isNormalDir()) {
2094	StringRef Dir = DL.getDirRef()->getName();
2095	if (CheckDir(Dir)) {
2096	if (IsAngled)
2097	*IsAngled = BestPrefixLength && isSystem(CK: DL.getDirCharacteristic());
2098	BestPrefixIsFramework = false;
2099	}
2100	} else if (DL.isFramework()) {
2101	StringRef Dir = DL.getFrameworkDirRef()->getName();
2102	if (CheckDir(Dir)) {
2103	// Framework includes by convention use <>.
2104	if (IsAngled)
2105	*IsAngled = BestPrefixLength;
2106	BestPrefixIsFramework = true;
2107	}
2108	}
2109	}
2110
2111	// Try to shorten include path using TUs directory, if we couldn't find any
2112	// suitable prefix in include search paths.
2113	if (!BestPrefixLength && CheckDir(path::parent_path(path: MainFile))) {
2114	if (IsAngled)
2115	*IsAngled = false;
2116	BestPrefixIsFramework = false;
2117	}
2118
2119	// Try resolving resulting filename via reverse search in header maps,
2120	// key from header name is user preferred name for the include file.
2121	StringRef Filename = File.drop_front(N: BestPrefixLength);
2122	for (const DirectoryLookup &DL : search_dir_range()) {
2123	if (!DL.isHeaderMap())
2124	continue;
2125
2126	StringRef SpelledFilename =
2127	DL.getHeaderMap()->reverseLookupFilename(DestPath: Filename);
2128	if (!SpelledFilename.empty()) {
2129	Filename = SpelledFilename;
2130	BestPrefixIsFramework = false;
2131	break;
2132	}
2133	}
2134
2135	// If the best prefix is a framework path, we need to compute the proper
2136	// include spelling for the framework header.
2137	bool IsPrivateHeader;
2138	SmallString<128> FrameworkName, IncludeSpelling;
2139	if (BestPrefixIsFramework &&
2140	isFrameworkStylePath(Path: Filename, IsPrivateHeader, FrameworkName,
2141	IncludeSpelling)) {
2142	Filename = IncludeSpelling;
2143	}
2144	return path::convert_to_slash(path: Filename);
2145	}
2146