1//===--- Module.h - Describe a module ---------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9///
10/// \file
11/// \brief Defines the clang::Module class, which describes a module in the
12/// source code.
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/PointerIntPair.h"
23#include "llvm/ADT/PointerUnion.h"
24#include "llvm/ADT/SetVector.h"
25#include "llvm/ADT/SmallVector.h"
26#include "llvm/ADT/STLExtras.h"
27#include "llvm/ADT/StringMap.h"
28#include "llvm/ADT/StringRef.h"
29#include <string>
30#include <utility>
31#include <vector>
32
33namespace llvm {
34  class raw_ostream;
35}
36
37namespace clang {
38
39class LangOptions;
40class TargetInfo;
41class IdentifierInfo;
42
43/// \brief Describes the name of a module.
44typedef SmallVector<std::pair<std::string, SourceLocation>, 2> ModuleId;
45
46/// \brief Describes a module or submodule.
47class Module {
48public:
49  /// \brief The name of this module.
50  std::string Name;
51
52  /// \brief The location of the module definition.
53  SourceLocation DefinitionLoc;
54
55  /// \brief The parent of this module. This will be NULL for the top-level
56  /// module.
57  Module *Parent;
58
59  /// \brief The build directory of this module. This is the directory in
60  /// which the module is notionally built, and relative to which its headers
61  /// are found.
62  const DirectoryEntry *Directory;
63
64  /// \brief The umbrella header or directory.
65  llvm::PointerUnion<const DirectoryEntry *, const FileEntry *> Umbrella;
66
67  /// \brief The module signature.
68  uint64_t Signature;
69
70  /// \brief The name of the umbrella entry, as written in the module map.
71  std::string UmbrellaAsWritten;
72
73private:
74  /// \brief The submodules of this module, indexed by name.
75  std::vector<Module *> SubModules;
76
77  /// \brief A mapping from the submodule name to the index into the
78  /// \c SubModules vector at which that submodule resides.
79  llvm::StringMap<unsigned> SubModuleIndex;
80
81  /// \brief The AST file if this is a top-level module which has a
82  /// corresponding serialized AST file, or null otherwise.
83  const FileEntry *ASTFile;
84
85  /// \brief The top-level headers associated with this module.
86  llvm::SmallSetVector<const FileEntry *, 2> TopHeaders;
87
88  /// \brief top-level header filenames that aren't resolved to FileEntries yet.
89  std::vector<std::string> TopHeaderNames;
90
91  /// \brief Cache of modules visible to lookup in this module.
92  mutable llvm::DenseSet<const Module*> VisibleModulesCache;
93
94  /// The ID used when referencing this module within a VisibleModuleSet.
95  unsigned VisibilityID;
96
97public:
98  enum HeaderKind {
99    HK_Normal,
100    HK_Textual,
101    HK_Private,
102    HK_PrivateTextual,
103    HK_Excluded
104  };
105  static const int NumHeaderKinds = HK_Excluded + 1;
106
107  /// \brief Information about a header directive as found in the module map
108  /// file.
109  struct Header {
110    std::string NameAsWritten;
111    const FileEntry *Entry;
112
113    explicit operator bool() { return Entry; }
114  };
115
116  /// \brief Information about a directory name as found in the module map
117  /// file.
118  struct DirectoryName {
119    std::string NameAsWritten;
120    const DirectoryEntry *Entry;
121
122    explicit operator bool() { return Entry; }
123  };
124
125  /// \brief The headers that are part of this module.
126  SmallVector<Header, 2> Headers[5];
127
128  /// \brief Stored information about a header directive that was found in the
129  /// module map file but has not been resolved to a file.
130  struct UnresolvedHeaderDirective {
131    SourceLocation FileNameLoc;
132    std::string FileName;
133    bool IsUmbrella;
134  };
135
136  /// \brief Headers that are mentioned in the module map file but could not be
137  /// found on the file system.
138  SmallVector<UnresolvedHeaderDirective, 1> MissingHeaders;
139
140  /// \brief An individual requirement: a feature name and a flag indicating
141  /// the required state of that feature.
142  typedef std::pair<std::string, bool> Requirement;
143
144  /// \brief The set of language features required to use this module.
145  ///
146  /// If any of these requirements are not available, the \c IsAvailable bit
147  /// will be false to indicate that this (sub)module is not available.
148  SmallVector<Requirement, 2> Requirements;
149
150  /// \brief Whether this module is missing a feature from \c Requirements.
151  unsigned IsMissingRequirement : 1;
152
153  /// \brief Whether we tried and failed to load a module file for this module.
154  unsigned HasIncompatibleModuleFile : 1;
155
156  /// \brief Whether this module is available in the current translation unit.
157  ///
158  /// If the module is missing headers or does not meet all requirements then
159  /// this bit will be 0.
160  unsigned IsAvailable : 1;
161
162  /// \brief Whether this module was loaded from a module file.
163  unsigned IsFromModuleFile : 1;
164
165  /// \brief Whether this is a framework module.
166  unsigned IsFramework : 1;
167
168  /// \brief Whether this is an explicit submodule.
169  unsigned IsExplicit : 1;
170
171  /// \brief Whether this is a "system" module (which assumes that all
172  /// headers in it are system headers).
173  unsigned IsSystem : 1;
174
175  /// \brief Whether this is an 'extern "C"' module (which implicitly puts all
176  /// headers in it within an 'extern "C"' block, and allows the module to be
177  /// imported within such a block).
178  unsigned IsExternC : 1;
179
180  /// \brief Whether this is an inferred submodule (module * { ... }).
181  unsigned IsInferred : 1;
182
183  /// \brief Whether we should infer submodules for this module based on
184  /// the headers.
185  ///
186  /// Submodules can only be inferred for modules with an umbrella header.
187  unsigned InferSubmodules : 1;
188
189  /// \brief Whether, when inferring submodules, the inferred submodules
190  /// should be explicit.
191  unsigned InferExplicitSubmodules : 1;
192
193  /// \brief Whether, when inferring submodules, the inferr submodules should
194  /// export all modules they import (e.g., the equivalent of "export *").
195  unsigned InferExportWildcard : 1;
196
197  /// \brief Whether the set of configuration macros is exhaustive.
198  ///
199  /// When the set of configuration macros is exhaustive, meaning
200  /// that no identifier not in this list should affect how the module is
201  /// built.
202  unsigned ConfigMacrosExhaustive : 1;
203
204  /// \brief Describes the visibility of the various names within a
205  /// particular module.
206  enum NameVisibilityKind {
207    /// \brief All of the names in this module are hidden.
208    Hidden,
209    /// \brief All of the names in this module are visible.
210    AllVisible
211  };
212
213  /// \brief The visibility of names within this particular module.
214  NameVisibilityKind NameVisibility;
215
216  /// \brief The location of the inferred submodule.
217  SourceLocation InferredSubmoduleLoc;
218
219  /// \brief The set of modules imported by this module, and on which this
220  /// module depends.
221  llvm::SmallSetVector<Module *, 2> Imports;
222
223  /// \brief Describes an exported module.
224  ///
225  /// The pointer is the module being re-exported, while the bit will be true
226  /// to indicate that this is a wildcard export.
227  typedef llvm::PointerIntPair<Module *, 1, bool> ExportDecl;
228
229  /// \brief The set of export declarations.
230  SmallVector<ExportDecl, 2> Exports;
231
232  /// \brief Describes an exported module that has not yet been resolved
233  /// (perhaps because the module it refers to has not yet been loaded).
234  struct UnresolvedExportDecl {
235    /// \brief The location of the 'export' keyword in the module map file.
236    SourceLocation ExportLoc;
237
238    /// \brief The name of the module.
239    ModuleId Id;
240
241    /// \brief Whether this export declaration ends in a wildcard, indicating
242    /// that all of its submodules should be exported (rather than the named
243    /// module itself).
244    bool Wildcard;
245  };
246
247  /// \brief The set of export declarations that have yet to be resolved.
248  SmallVector<UnresolvedExportDecl, 2> UnresolvedExports;
249
250  /// \brief The directly used modules.
251  SmallVector<Module *, 2> DirectUses;
252
253  /// \brief The set of use declarations that have yet to be resolved.
254  SmallVector<ModuleId, 2> UnresolvedDirectUses;
255
256  /// \brief A library or framework to link against when an entity from this
257  /// module is used.
258  struct LinkLibrary {
259    LinkLibrary() : IsFramework(false) { }
260    LinkLibrary(const std::string &Library, bool IsFramework)
261      : Library(Library), IsFramework(IsFramework) { }
262
263    /// \brief The library to link against.
264    ///
265    /// This will typically be a library or framework name, but can also
266    /// be an absolute path to the library or framework.
267    std::string Library;
268
269    /// \brief Whether this is a framework rather than a library.
270    bool IsFramework;
271  };
272
273  /// \brief The set of libraries or frameworks to link against when
274  /// an entity from this module is used.
275  llvm::SmallVector<LinkLibrary, 2> LinkLibraries;
276
277  /// \brief The set of "configuration macros", which are macros that
278  /// (intentionally) change how this module is built.
279  std::vector<std::string> ConfigMacros;
280
281  /// \brief An unresolved conflict with another module.
282  struct UnresolvedConflict {
283    /// \brief The (unresolved) module id.
284    ModuleId Id;
285
286    /// \brief The message provided to the user when there is a conflict.
287    std::string Message;
288  };
289
290  /// \brief The list of conflicts for which the module-id has not yet been
291  /// resolved.
292  std::vector<UnresolvedConflict> UnresolvedConflicts;
293
294  /// \brief A conflict between two modules.
295  struct Conflict {
296    /// \brief The module that this module conflicts with.
297    Module *Other;
298
299    /// \brief The message provided to the user when there is a conflict.
300    std::string Message;
301  };
302
303  /// \brief The list of conflicts.
304  std::vector<Conflict> Conflicts;
305
306  /// \brief Construct a new module or submodule.
307  Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent,
308         bool IsFramework, bool IsExplicit, unsigned VisibilityID);
309
310  ~Module();
311
312  /// \brief Determine whether this module is available for use within the
313  /// current translation unit.
314  bool isAvailable() const { return IsAvailable; }
315
316  /// \brief Determine whether this module is available for use within the
317  /// current translation unit.
318  ///
319  /// \param LangOpts The language options used for the current
320  /// translation unit.
321  ///
322  /// \param Target The target options used for the current translation unit.
323  ///
324  /// \param Req If this module is unavailable, this parameter
325  /// will be set to one of the requirements that is not met for use of
326  /// this module.
327  bool isAvailable(const LangOptions &LangOpts,
328                   const TargetInfo &Target,
329                   Requirement &Req,
330                   UnresolvedHeaderDirective &MissingHeader) const;
331
332  /// \brief Determine whether this module is a submodule.
333  bool isSubModule() const { return Parent != nullptr; }
334
335  /// \brief Determine whether this module is a submodule of the given other
336  /// module.
337  bool isSubModuleOf(const Module *Other) const;
338
339  /// \brief Determine whether this module is a part of a framework,
340  /// either because it is a framework module or because it is a submodule
341  /// of a framework module.
342  bool isPartOfFramework() const {
343    for (const Module *Mod = this; Mod; Mod = Mod->Parent)
344      if (Mod->IsFramework)
345        return true;
346
347    return false;
348  }
349
350  /// \brief Determine whether this module is a subframework of another
351  /// framework.
352  bool isSubFramework() const {
353    return IsFramework && Parent && Parent->isPartOfFramework();
354  }
355
356  /// \brief Retrieve the full name of this module, including the path from
357  /// its top-level module.
358  std::string getFullModuleName() const;
359
360  /// \brief Whether the full name of this module is equal to joining
361  /// \p nameParts with "."s.
362  ///
363  /// This is more efficient than getFullModuleName().
364  bool fullModuleNameIs(ArrayRef<StringRef> nameParts) const;
365
366  /// \brief Retrieve the top-level module for this (sub)module, which may
367  /// be this module.
368  Module *getTopLevelModule() {
369    return const_cast<Module *>(
370             const_cast<const Module *>(this)->getTopLevelModule());
371  }
372
373  /// \brief Retrieve the top-level module for this (sub)module, which may
374  /// be this module.
375  const Module *getTopLevelModule() const;
376
377  /// \brief Retrieve the name of the top-level module.
378  ///
379  StringRef getTopLevelModuleName() const {
380    return getTopLevelModule()->Name;
381  }
382
383  /// \brief The serialized AST file for this module, if one was created.
384  const FileEntry *getASTFile() const {
385    return getTopLevelModule()->ASTFile;
386  }
387
388  /// \brief Set the serialized AST file for the top-level module of this module.
389  void setASTFile(const FileEntry *File) {
390    assert((File == nullptr || getASTFile() == nullptr ||
391            getASTFile() == File) && "file path changed");
392    getTopLevelModule()->ASTFile = File;
393  }
394
395  /// \brief Retrieve the directory for which this module serves as the
396  /// umbrella.
397  DirectoryName getUmbrellaDir() const;
398
399  /// \brief Retrieve the header that serves as the umbrella header for this
400  /// module.
401  Header getUmbrellaHeader() const {
402    if (auto *E = Umbrella.dyn_cast<const FileEntry *>())
403      return Header{UmbrellaAsWritten, E};
404    return Header{};
405  }
406
407  /// \brief Determine whether this module has an umbrella directory that is
408  /// not based on an umbrella header.
409  bool hasUmbrellaDir() const {
410    return Umbrella && Umbrella.is<const DirectoryEntry *>();
411  }
412
413  /// \brief Add a top-level header associated with this module.
414  void addTopHeader(const FileEntry *File) {
415    assert(File);
416    TopHeaders.insert(File);
417  }
418
419  /// \brief Add a top-level header filename associated with this module.
420  void addTopHeaderFilename(StringRef Filename) {
421    TopHeaderNames.push_back(Filename);
422  }
423
424  /// \brief The top-level headers associated with this module.
425  ArrayRef<const FileEntry *> getTopHeaders(FileManager &FileMgr);
426
427  /// \brief Determine whether this module has declared its intention to
428  /// directly use another module.
429  bool directlyUses(const Module *Requested) const;
430
431  /// \brief Add the given feature requirement to the list of features
432  /// required by this module.
433  ///
434  /// \param Feature The feature that is required by this module (and
435  /// its submodules).
436  ///
437  /// \param RequiredState The required state of this feature: \c true
438  /// if it must be present, \c false if it must be absent.
439  ///
440  /// \param LangOpts The set of language options that will be used to
441  /// evaluate the availability of this feature.
442  ///
443  /// \param Target The target options that will be used to evaluate the
444  /// availability of this feature.
445  void addRequirement(StringRef Feature, bool RequiredState,
446                      const LangOptions &LangOpts,
447                      const TargetInfo &Target);
448
449  /// \brief Mark this module and all of its submodules as unavailable.
450  void markUnavailable(bool MissingRequirement = false);
451
452  /// \brief Find the submodule with the given name.
453  ///
454  /// \returns The submodule if found, or NULL otherwise.
455  Module *findSubmodule(StringRef Name) const;
456
457  /// \brief Determine whether the specified module would be visible to
458  /// a lookup at the end of this module.
459  ///
460  /// FIXME: This may return incorrect results for (submodules of) the
461  /// module currently being built, if it's queried before we see all
462  /// of its imports.
463  bool isModuleVisible(const Module *M) const {
464    if (VisibleModulesCache.empty())
465      buildVisibleModulesCache();
466    return VisibleModulesCache.count(M);
467  }
468
469  unsigned getVisibilityID() const { return VisibilityID; }
470
471  typedef std::vector<Module *>::iterator submodule_iterator;
472  typedef std::vector<Module *>::const_iterator submodule_const_iterator;
473
474  submodule_iterator submodule_begin() { return SubModules.begin(); }
475  submodule_const_iterator submodule_begin() const {return SubModules.begin();}
476  submodule_iterator submodule_end()   { return SubModules.end(); }
477  submodule_const_iterator submodule_end() const { return SubModules.end(); }
478
479  llvm::iterator_range<submodule_iterator> submodules() {
480    return llvm::make_range(submodule_begin(), submodule_end());
481  }
482  llvm::iterator_range<submodule_const_iterator> submodules() const {
483    return llvm::make_range(submodule_begin(), submodule_end());
484  }
485
486  /// \brief Appends this module's list of exported modules to \p Exported.
487  ///
488  /// This provides a subset of immediately imported modules (the ones that are
489  /// directly exported), not the complete set of exported modules.
490  void getExportedModules(SmallVectorImpl<Module *> &Exported) const;
491
492  static StringRef getModuleInputBufferName() {
493    return "<module-includes>";
494  }
495
496  /// \brief Print the module map for this module to the given stream.
497  ///
498  void print(raw_ostream &OS, unsigned Indent = 0) const;
499
500  /// \brief Dump the contents of this module to the given output stream.
501  void dump() const;
502
503private:
504  void buildVisibleModulesCache() const;
505};
506
507/// \brief A set of visible modules.
508class VisibleModuleSet {
509public:
510  VisibleModuleSet() : Generation(0) {}
511  VisibleModuleSet(VisibleModuleSet &&O)
512      : ImportLocs(std::move(O.ImportLocs)), Generation(O.Generation ? 1 : 0) {
513    O.ImportLocs.clear();
514    ++O.Generation;
515  }
516
517  /// Move from another visible modules set. Guaranteed to leave the source
518  /// empty and bump the generation on both.
519  VisibleModuleSet &operator=(VisibleModuleSet &&O) {
520    ImportLocs = std::move(O.ImportLocs);
521    O.ImportLocs.clear();
522    ++O.Generation;
523    ++Generation;
524    return *this;
525  }
526
527  /// \brief Get the current visibility generation. Incremented each time the
528  /// set of visible modules changes in any way.
529  unsigned getGeneration() const { return Generation; }
530
531  /// \brief Determine whether a module is visible.
532  bool isVisible(const Module *M) const {
533    return getImportLoc(M).isValid();
534  }
535
536  /// \brief Get the location at which the import of a module was triggered.
537  SourceLocation getImportLoc(const Module *M) const {
538    return M->getVisibilityID() < ImportLocs.size()
539               ? ImportLocs[M->getVisibilityID()]
540               : SourceLocation();
541  }
542
543  /// \brief A callback to call when a module is made visible (directly or
544  /// indirectly) by a call to \ref setVisible.
545  typedef llvm::function_ref<void(Module *M)> VisibleCallback;
546  /// \brief A callback to call when a module conflict is found. \p Path
547  /// consists of a sequence of modules from the conflicting module to the one
548  /// made visible, where each was exported by the next.
549  typedef llvm::function_ref<void(ArrayRef<Module *> Path,
550                                  Module *Conflict, StringRef Message)>
551      ConflictCallback;
552  /// \brief Make a specific module visible.
553  void setVisible(Module *M, SourceLocation Loc,
554                  VisibleCallback Vis = [](Module *) {},
555                  ConflictCallback Cb = [](ArrayRef<Module *>, Module *,
556                                           StringRef) {});
557
558private:
559  /// Import locations for each visible module. Indexed by the module's
560  /// VisibilityID.
561  std::vector<SourceLocation> ImportLocs;
562  /// Visibility generation, bumped every time the visibility state changes.
563  unsigned Generation;
564};
565
566} // end namespace clang
567
568
569#endif // LLVM_CLANG_BASIC_MODULE_H
570