Module.h source code [clang_source_code/include/clang/Basic/Module.h]

1	//===- Module.h - Describe a module ------------------------------ 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 clang::Module class, which describes a module in the
11	/// source code.
12	//
13	//===----------------------------------------------------------------------===//
14
15	#ifndef LLVM_CLANG_BASIC_MODULE_H
16	#define LLVM_CLANG_BASIC_MODULE_H
17
18	#include "clang/Basic/FileManager.h"
19	#include "clang/Basic/SourceLocation.h"
20	#include "llvm/ADT/ArrayRef.h"
21	#include "llvm/ADT/DenseSet.h"
22	#include "llvm/ADT/Optional.h"
23	#include "llvm/ADT/PointerIntPair.h"
24	#include "llvm/ADT/PointerUnion.h"
25	#include "llvm/ADT/SetVector.h"
26	#include "llvm/ADT/SmallVector.h"
27	#include "llvm/ADT/STLExtras.h"
28	#include "llvm/ADT/StringMap.h"
29	#include "llvm/ADT/StringRef.h"
30	#include "llvm/ADT/iterator_range.h"
31	#include <array>
32	#include <cassert>
33	#include <cstdint>
34	#include <ctime>
35	#include <string>
36	#include <utility>
37	#include <vector>
38
39	namespace llvm {
40
41	class raw_ostream;
42
43	} // namespace llvm
44
45	namespace clang {
46
47	class LangOptions;
48	class TargetInfo;
49
50	/// Describes the name of a module.
51	using ModuleId = SmallVector<std::pair<std::string, SourceLocation>, 2>;
52
53	/// The signature of a module, which is a hash of the AST content.
54	struct ASTFileSignature : std::array<uint32_t, 5> {
55	ASTFileSignature(std::array<uint32_t, 5> S = {{0}})
56	: std::array<uint32_t, 5>(std::move(S)) {}
57
58	explicit operator bool() const {
59	return *this != std::array<uint32_t, 5>({{0}});
60	}
61	};
62
63	/// Describes a module or submodule.
64	class Module {
65	public:
66	/// The name of this module.
67	std::string Name;
68
69	/// The location of the module definition.
70	SourceLocation DefinitionLoc;
71
72	enum ModuleKind {
73	/// This is a module that was defined by a module map and built out
74	/// of header files.
75	ModuleMapModule,
76
77	/// This is a C++ Modules TS module interface unit.
78	ModuleInterfaceUnit,
79
80	/// This is a fragment of the global module within some C++ Modules
81	/// TS module.
82	GlobalModuleFragment,
83	};
84
85	/// The kind of this module.
86	ModuleKind Kind = ModuleMapModule;
87
88	/// The parent of this module. This will be NULL for the top-level
89	/// module.
90	Module *Parent;
91
92	/// The build directory of this module. This is the directory in
93	/// which the module is notionally built, and relative to which its headers
94	/// are found.
95	const DirectoryEntry *Directory = nullptr;
96
97	/// The presumed file name for the module map defining this module.
98	/// Only non-empty when building from preprocessed source.
99	std::string PresumedModuleMapFile;
100
101	/// The umbrella header or directory.
102	llvm::PointerUnion<const DirectoryEntry , const FileEntry > Umbrella;
103
104	/// The module signature.
105	ASTFileSignature Signature;
106
107	/// The name of the umbrella entry, as written in the module map.
108	std::string UmbrellaAsWritten;
109
110	/// The module through which entities defined in this module will
111	/// eventually be exposed, for use in "private" modules.
112	std::string ExportAsModule;
113
114	private:
115	/// The submodules of this module, indexed by name.
116	std::vector<Module *> SubModules;
117
118	/// A mapping from the submodule name to the index into the
119	/// \c SubModules vector at which that submodule resides.
120	llvm::StringMap<unsigned> SubModuleIndex;
121
122	/// The AST file if this is a top-level module which has a
123	/// corresponding serialized AST file, or null otherwise.
124	const FileEntry *ASTFile = nullptr;
125
126	/// The top-level headers associated with this module.
127	llvm::SmallSetVector<const FileEntry *, 2> TopHeaders;
128
129	/// top-level header filenames that aren't resolved to FileEntries yet.
130	std::vector<std::string> TopHeaderNames;
131
132	/// Cache of modules visible to lookup in this module.
133	mutable llvm::DenseSet<const Module*> VisibleModulesCache;
134
135	/// The ID used when referencing this module within a VisibleModuleSet.
136	unsigned VisibilityID;
137
138	public:
139	enum HeaderKind {
140	HK_Normal,
141	HK_Textual,
142	HK_Private,
143	HK_PrivateTextual,
144	HK_Excluded
145	};
146	static const int NumHeaderKinds = HK_Excluded + 1;
147
148	/// Information about a header directive as found in the module map
149	/// file.
150	struct Header {
151	std::string NameAsWritten;
152	const FileEntry *Entry;
153
154	explicit operator bool() { return Entry; }
155	};
156
157	/// Information about a directory name as found in the module map
158	/// file.
159	struct DirectoryName {
160	std::string NameAsWritten;
161	const DirectoryEntry *Entry;
162
163	explicit operator bool() { return Entry; }
164	};
165
166	/// The headers that are part of this module.
167	SmallVector<Header, 2> Headers[5];
168
169	/// Stored information about a header directive that was found in the
170	/// module map file but has not been resolved to a file.
171	struct UnresolvedHeaderDirective {
172	HeaderKind Kind = HK_Normal;
173	SourceLocation FileNameLoc;
174	std::string FileName;
175	bool IsUmbrella = false;
176	bool HasBuiltinHeader = false;
177	Optional<off_t> Size;
178	Optional<time_t> ModTime;
179	};
180
181	/// Headers that are mentioned in the module map file but that we have not
182	/// yet attempted to resolve to a file on the file system.
183	SmallVector<UnresolvedHeaderDirective, 1> UnresolvedHeaders;
184
185	/// Headers that are mentioned in the module map file but could not be
186	/// found on the file system.
187	SmallVector<UnresolvedHeaderDirective, 1> MissingHeaders;
188
189	/// An individual requirement: a feature name and a flag indicating
190	/// the required state of that feature.
191	using Requirement = std::pair<std::string, bool>;
192
193	/// The set of language features required to use this module.
194	///
195	/// If any of these requirements are not available, the \c IsAvailable bit
196	/// will be false to indicate that this (sub)module is not available.
197	SmallVector<Requirement, 2> Requirements;
198
199	/// A module with the same name that shadows this module.
200	Module *ShadowingModule = nullptr;
201
202	/// Whether this module is missing a feature from \c Requirements.
203	unsigned IsMissingRequirement : 1;
204
205	/// Whether we tried and failed to load a module file for this module.
206	unsigned HasIncompatibleModuleFile : 1;
207
208	/// Whether this module is available in the current translation unit.
209	///
210	/// If the module is missing headers or does not meet all requirements then
211	/// this bit will be 0.
212	unsigned IsAvailable : 1;
213
214	/// Whether this module was loaded from a module file.
215	unsigned IsFromModuleFile : 1;
216
217	/// Whether this is a framework module.
218	unsigned IsFramework : 1;
219
220	/// Whether this is an explicit submodule.
221	unsigned IsExplicit : 1;
222
223	/// Whether this is a "system" module (which assumes that all
224	/// headers in it are system headers).
225	unsigned IsSystem : 1;
226
227	/// Whether this is an 'extern "C"' module (which implicitly puts all
228	/// headers in it within an 'extern "C"' block, and allows the module to be
229	/// imported within such a block).
230	unsigned IsExternC : 1;
231
232	/// Whether this is an inferred submodule (module * { ... }).
233	unsigned IsInferred : 1;
234
235	/// Whether we should infer submodules for this module based on
236	/// the headers.
237	///
238	/// Submodules can only be inferred for modules with an umbrella header.
239	unsigned InferSubmodules : 1;
240
241	/// Whether, when inferring submodules, the inferred submodules
242	/// should be explicit.
243	unsigned InferExplicitSubmodules : 1;
244
245	/// Whether, when inferring submodules, the inferr submodules should
246	/// export all modules they import (e.g., the equivalent of "export *").
247	unsigned InferExportWildcard : 1;
248
249	/// Whether the set of configuration macros is exhaustive.
250	///
251	/// When the set of configuration macros is exhaustive, meaning
252	/// that no identifier not in this list should affect how the module is
253	/// built.
254	unsigned ConfigMacrosExhaustive : 1;
255
256	/// Whether files in this module can only include non-modular headers
257	/// and headers from used modules.
258	unsigned NoUndeclaredIncludes : 1;
259
260	/// Whether this module came from a "private" module map, found next
261	/// to a regular (public) module map.
262	unsigned ModuleMapIsPrivate : 1;
263
264	/// Describes the visibility of the various names within a
265	/// particular module.
266	enum NameVisibilityKind {
267	/// All of the names in this module are hidden.
268	Hidden,
269	/// All of the names in this module are visible.
270	AllVisible
271	};
272
273	/// The visibility of names within this particular module.
274	NameVisibilityKind NameVisibility;
275
276	/// The location of the inferred submodule.
277	SourceLocation InferredSubmoduleLoc;
278
279	/// The set of modules imported by this module, and on which this
280	/// module depends.
281	llvm::SmallSetVector<Module *, 2> Imports;
282
283	/// Describes an exported module.
284	///
285	/// The pointer is the module being re-exported, while the bit will be true
286	/// to indicate that this is a wildcard export.
287	using ExportDecl = llvm::PointerIntPair<Module *, 1, bool>;
288
289	/// The set of export declarations.
290	SmallVector<ExportDecl, 2> Exports;
291
292	/// Describes an exported module that has not yet been resolved
293	/// (perhaps because the module it refers to has not yet been loaded).
294	struct UnresolvedExportDecl {
295	/// The location of the 'export' keyword in the module map file.
296	SourceLocation ExportLoc;
297
298	/// The name of the module.
299	ModuleId Id;
300
301	/// Whether this export declaration ends in a wildcard, indicating
302	/// that all of its submodules should be exported (rather than the named
303	/// module itself).
304	bool Wildcard;
305	};
306
307	/// The set of export declarations that have yet to be resolved.
308	SmallVector<UnresolvedExportDecl, 2> UnresolvedExports;
309
310	/// The directly used modules.
311	SmallVector<Module *, 2> DirectUses;
312
313	/// The set of use declarations that have yet to be resolved.
314	SmallVector<ModuleId, 2> UnresolvedDirectUses;
315
316	/// A library or framework to link against when an entity from this
317	/// module is used.
318	struct LinkLibrary {
319	LinkLibrary() = default;
320	LinkLibrary(const std::string &Library, bool IsFramework)
321	: Library(Library), IsFramework(IsFramework) {}
322
323	/// The library to link against.
324	///
325	/// This will typically be a library or framework name, but can also
326	/// be an absolute path to the library or framework.
327	std::string Library;
328
329	/// Whether this is a framework rather than a library.
330	bool IsFramework = false;
331	};
332
333	/// The set of libraries or frameworks to link against when
334	/// an entity from this module is used.
335	llvm::SmallVector<LinkLibrary, 2> LinkLibraries;
336
337	/// Autolinking uses the framework name for linking purposes
338	/// when this is false and the export_as name otherwise.
339	bool UseExportAsModuleLinkName = false;
340
341	/// The set of "configuration macros", which are macros that
342	/// (intentionally) change how this module is built.
343	std::vector<std::string> ConfigMacros;
344
345	/// An unresolved conflict with another module.
346	struct UnresolvedConflict {
347	/// The (unresolved) module id.
348	ModuleId Id;
349
350	/// The message provided to the user when there is a conflict.
351	std::string Message;
352	};
353
354	/// The list of conflicts for which the module-id has not yet been
355	/// resolved.
356	std::vector<UnresolvedConflict> UnresolvedConflicts;
357
358	/// A conflict between two modules.
359	struct Conflict {
360	/// The module that this module conflicts with.
361	Module *Other;
362
363	/// The message provided to the user when there is a conflict.
364	std::string Message;
365	};
366
367	/// The list of conflicts.
368	std::vector<Conflict> Conflicts;
369
370	/// Construct a new module or submodule.
371	Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent,
372	bool IsFramework, bool IsExplicit, unsigned VisibilityID);
373
374	~Module();
375
376	/// Determine whether this module is available for use within the
377	/// current translation unit.
378	bool isAvailable() const { return IsAvailable; }
379
380	/// Determine whether this module is available for use within the
381	/// current translation unit.
382	///
383	/// \param LangOpts The language options used for the current
384	/// translation unit.
385	///
386	/// \param Target The target options used for the current translation unit.
387	///
388	/// \param Req If this module is unavailable because of a missing requirement,
389	/// this parameter will be set to one of the requirements that is not met for
390	/// use of this module.
391	///
392	/// \param MissingHeader If this module is unavailable because of a missing
393	/// header, this parameter will be set to one of the missing headers.
394	///
395	/// \param ShadowingModule If this module is unavailable because it is
396	/// shadowed, this parameter will be set to the shadowing module.
397	bool isAvailable(const LangOptions &LangOpts,
398	const TargetInfo &Target,
399	Requirement &Req,
400	UnresolvedHeaderDirective &MissingHeader,
401	Module *&ShadowingModule) const;
402
403	/// Determine whether this module is a submodule.
404	bool isSubModule() const { return Parent != nullptr; }
405
406	/// Determine whether this module is a submodule of the given other
407	/// module.
408	bool isSubModuleOf(const Module *Other) const;
409
410	/// Determine whether this module is a part of a framework,
411	/// either because it is a framework module or because it is a submodule
412	/// of a framework module.
413	bool isPartOfFramework() const {
414	for (const Module *Mod = this; Mod; Mod = Mod->Parent)
415	if (Mod->IsFramework)
416	return true;
417
418	return false;
419	}
420
421	/// Determine whether this module is a subframework of another
422	/// framework.
423	bool isSubFramework() const {
424	return IsFramework && Parent && Parent->isPartOfFramework();
425	}
426
427	/// Set the parent of this module. This should only be used if the parent
428	/// could not be set during module creation.
429	void setParent(Module *M) {
430	assert(!Parent);
431	Parent = M;
432	Parent->SubModuleIndex[Name] = Parent->SubModules.size();
433	Parent->SubModules.push_back(this);
434	}
435
436	/// Retrieve the full name of this module, including the path from
437	/// its top-level module.
438	/// \param AllowStringLiterals If \c true, components that might not be
439	/// lexically valid as identifiers will be emitted as string literals.
440	std::string getFullModuleName(bool AllowStringLiterals = false) const;
441
442	/// Whether the full name of this module is equal to joining
443	/// \p nameParts with "."s.
444	///
445	/// This is more efficient than getFullModuleName().
446	bool fullModuleNameIs(ArrayRef<StringRef> nameParts) const;
447
448	/// Retrieve the top-level module for this (sub)module, which may
449	/// be this module.
450	Module *getTopLevelModule() {
451	return const_cast<Module *>(
452	const_cast<const Module *>(this)->getTopLevelModule());
453	}
454
455	/// Retrieve the top-level module for this (sub)module, which may
456	/// be this module.
457	const Module *getTopLevelModule() const;
458
459	/// Retrieve the name of the top-level module.
460	StringRef getTopLevelModuleName() const {
461	return getTopLevelModule()->Name;
462	}
463
464	/// The serialized AST file for this module, if one was created.
465	const FileEntry *getASTFile() const {
466	return getTopLevelModule()->ASTFile;
467	}
468
469	/// Set the serialized AST file for the top-level module of this module.
470	void setASTFile(const FileEntry *File) {
471	(0) . __assert_fail ("(File == nullptr \|\| getASTFile() == nullptr \|\| getASTFile() == File) && \"file path changed\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Basic/Module.h", 472, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert((File == nullptr \|\| getASTFile() == nullptr \|\|
472	(0) . __assert_fail ("(File == nullptr \|\| getASTFile() == nullptr \|\| getASTFile() == File) && \"file path changed\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Basic/Module.h", 472, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> getASTFile() == File) && "file path changed");
473	getTopLevelModule()->ASTFile = File;
474	}
475
476	/// Retrieve the directory for which this module serves as the
477	/// umbrella.
478	DirectoryName getUmbrellaDir() const;
479
480	/// Retrieve the header that serves as the umbrella header for this
481	/// module.
482	Header getUmbrellaHeader() const {
483	if (auto E = Umbrella.dyn_cast<const FileEntry >())
484	return Header{UmbrellaAsWritten, E};
485	return Header{};
486	}
487
488	/// Determine whether this module has an umbrella directory that is
489	/// not based on an umbrella header.
490	bool hasUmbrellaDir() const {
491	return Umbrella && Umbrella.is<const DirectoryEntry *>();
492	}
493
494	/// Add a top-level header associated with this module.
495	void addTopHeader(const FileEntry *File) {
496	assert(File);
497	TopHeaders.insert(File);
498	}
499
500	/// Add a top-level header filename associated with this module.
501	void addTopHeaderFilename(StringRef Filename) {
502	TopHeaderNames.push_back(Filename);
503	}
504
505	/// The top-level headers associated with this module.
506	ArrayRef<const FileEntry *> getTopHeaders(FileManager &FileMgr);
507
508	/// Determine whether this module has declared its intention to
509	/// directly use another module.
510	bool directlyUses(const Module *Requested) const;
511
512	/// Add the given feature requirement to the list of features
513	/// required by this module.
514	///
515	/// \param Feature The feature that is required by this module (and
516	/// its submodules).
517	///
518	/// \param RequiredState The required state of this feature: \c true
519	/// if it must be present, \c false if it must be absent.
520	///
521	/// \param LangOpts The set of language options that will be used to
522	/// evaluate the availability of this feature.
523	///
524	/// \param Target The target options that will be used to evaluate the
525	/// availability of this feature.
526	void addRequirement(StringRef Feature, bool RequiredState,
527	const LangOptions &LangOpts,
528	const TargetInfo &Target);
529
530	/// Mark this module and all of its submodules as unavailable.
531	void markUnavailable(bool MissingRequirement = false);
532
533	/// Find the submodule with the given name.
534	///
535	/// \returns The submodule if found, or NULL otherwise.
536	Module *findSubmodule(StringRef Name) const;
537
538	/// Determine whether the specified module would be visible to
539	/// a lookup at the end of this module.
540	///
541	/// FIXME: This may return incorrect results for (submodules of) the
542	/// module currently being built, if it's queried before we see all
543	/// of its imports.
544	bool isModuleVisible(const Module *M) const {
545	if (VisibleModulesCache.empty())
546	buildVisibleModulesCache();
547	return VisibleModulesCache.count(M);
548	}
549
550	unsigned getVisibilityID() const { return VisibilityID; }
551
552	using submodule_iterator = std::vector<Module *>::iterator;
553	using submodule_const_iterator = std::vector<Module *>::const_iterator;
554
555	submodule_iterator submodule_begin() { return SubModules.begin(); }
556	submodule_const_iterator submodule_begin() const {return SubModules.begin();}
557	submodule_iterator submodule_end() { return SubModules.end(); }
558	submodule_const_iterator submodule_end() const { return SubModules.end(); }
559
560	llvm::iterator_range<submodule_iterator> submodules() {
561	return llvm::make_range(submodule_begin(), submodule_end());
562	}
563	llvm::iterator_range<submodule_const_iterator> submodules() const {
564	return llvm::make_range(submodule_begin(), submodule_end());
565	}
566
567	/// Appends this module's list of exported modules to \p Exported.
568	///
569	/// This provides a subset of immediately imported modules (the ones that are
570	/// directly exported), not the complete set of exported modules.
571	void getExportedModules(SmallVectorImpl<Module *> &Exported) const;
572
573	static StringRef getModuleInputBufferName() {
574	return "<module-includes>";
575	}
576
577	/// Print the module map for this module to the given stream.
578	void print(raw_ostream &OS, unsigned Indent = 0) const;
579
580	/// Dump the contents of this module to the given output stream.
581	void dump() const;
582
583	private:
584	void buildVisibleModulesCache() const;
585	};
586
587	/// A set of visible modules.
588	class VisibleModuleSet {
589	public:
590	VisibleModuleSet() = default;
591	VisibleModuleSet(VisibleModuleSet &&O)
592	: ImportLocs(std::move(O.ImportLocs)), Generation(O.Generation ? 1 : 0) {
593	O.ImportLocs.clear();
594	++O.Generation;
595	}
596
597	/// Move from another visible modules set. Guaranteed to leave the source
598	/// empty and bump the generation on both.
599	VisibleModuleSet &operator=(VisibleModuleSet &&O) {
600	ImportLocs = std::move(O.ImportLocs);
601	O.ImportLocs.clear();
602	++O.Generation;
603	++Generation;
604	return *this;
605	}
606
607	/// Get the current visibility generation. Incremented each time the
608	/// set of visible modules changes in any way.
609	unsigned getGeneration() const { return Generation; }
610
611	/// Determine whether a module is visible.
612	bool isVisible(const Module *M) const {
613	return getImportLoc(M).isValid();
614	}
615
616	/// Get the location at which the import of a module was triggered.
617	SourceLocation getImportLoc(const Module *M) const {
618	return M->getVisibilityID() < ImportLocs.size()
619	? ImportLocs[M->getVisibilityID()]
620	: SourceLocation();
621	}
622
623	/// A callback to call when a module is made visible (directly or
624	/// indirectly) by a call to \ref setVisible.
625	using VisibleCallback = llvm::function_ref<void(Module *M)>;
626
627	/// A callback to call when a module conflict is found. \p Path
628	/// consists of a sequence of modules from the conflicting module to the one
629	/// made visible, where each was exported by the next.
630	using ConflictCallback =
631	llvm::function_ref<void(ArrayRef<Module > Path, Module Conflict,
632	StringRef Message)>;
633
634	/// Make a specific module visible.
635	void setVisible(Module *M, SourceLocation Loc,
636	VisibleCallback Vis = [](Module *) {},
637	ConflictCallback Cb = [](ArrayRef<Module >, Module ,
638	StringRef) {});
639
640	private:
641	/// Import locations for each visible module. Indexed by the module's
642	/// VisibilityID.
643	std::vector<SourceLocation> ImportLocs;
644
645	/// Visibility generation, bumped every time the visibility state changes.
646	unsigned Generation = 0;
647	};
648
649	} // namespace clang
650
651	#endif // LLVM_CLANG_BASIC_MODULE_H
652