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1 //===--- ModuleMap.h - Describe the layout of modules -----------*- 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 // This file defines the ModuleMap interface, which describes the layout of a
11 // module as it relates to headers.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 
16 #ifndef LLVM_CLANG_LEX_MODULEMAP_H
17 #define LLVM_CLANG_LEX_MODULEMAP_H
18 
19 #include "clang/Basic/LangOptions.h"
20 #include "clang/Basic/Module.h"
21 #include "clang/Basic/SourceManager.h"
22 #include "llvm/ADT/DenseMap.h"
23 #include "llvm/ADT/IntrusiveRefCntPtr.h"
24 #include "llvm/ADT/SmallVector.h"
25 #include "llvm/ADT/StringMap.h"
26 #include "llvm/ADT/StringRef.h"
27 #include <string>
28 
29 namespace clang {
30 
31 class DirectoryEntry;
32 class FileEntry;
33 class FileManager;
34 class DiagnosticConsumer;
35 class DiagnosticsEngine;
36 class HeaderSearch;
37 class ModuleMapParser;
38 
39 /// \brief A mechanism to observe the actions of the module map parser as it
40 /// reads module map files.
41 class ModuleMapCallbacks {
42 public:
~ModuleMapCallbacks()43   virtual ~ModuleMapCallbacks() {}
44 
45   /// \brief Called when a module map file has been read.
46   ///
47   /// \param FileStart A SourceLocation referring to the start of the file's
48   /// contents.
49   /// \param File The file itself.
50   /// \param IsSystem Whether this is a module map from a system include path.
moduleMapFileRead(SourceLocation FileStart,const FileEntry & File,bool IsSystem)51   virtual void moduleMapFileRead(SourceLocation FileStart,
52                                  const FileEntry &File, bool IsSystem) {}
53 
54   /// \brief Called when a header is added during module map parsing.
55   ///
56   /// \param Filename The header file itself.
moduleMapAddHeader(StringRef Filename)57   virtual void moduleMapAddHeader(StringRef Filename) {}
58 
59   /// \brief Called when an umbrella header is added during module map parsing.
60   ///
61   /// \param FileMgr FileManager instance
62   /// \param Header The umbrella header to collect.
moduleMapAddUmbrellaHeader(FileManager * FileMgr,const FileEntry * Header)63   virtual void moduleMapAddUmbrellaHeader(FileManager *FileMgr,
64                                           const FileEntry *Header) {}
65 };
66 
67 class ModuleMap {
68   SourceManager &SourceMgr;
69   DiagnosticsEngine &Diags;
70   const LangOptions &LangOpts;
71   const TargetInfo *Target;
72   HeaderSearch &HeaderInfo;
73 
74   llvm::SmallVector<std::unique_ptr<ModuleMapCallbacks>, 1> Callbacks;
75 
76   /// \brief The directory used for Clang-supplied, builtin include headers,
77   /// such as "stdint.h".
78   const DirectoryEntry *BuiltinIncludeDir;
79 
80   /// \brief Language options used to parse the module map itself.
81   ///
82   /// These are always simple C language options.
83   LangOptions MMapLangOpts;
84 
85   // The module that the main source file is associated with (the module
86   // named LangOpts::CurrentModule, if we've loaded it).
87   Module *SourceModule;
88 
89   /// \brief The top-level modules that are known.
90   llvm::StringMap<Module *> Modules;
91 
92   /// \brief The number of modules we have created in total.
93   unsigned NumCreatedModules;
94 
95 public:
96   /// \brief Flags describing the role of a module header.
97   enum ModuleHeaderRole {
98     /// \brief This header is normally included in the module.
99     NormalHeader  = 0x0,
100     /// \brief This header is included but private.
101     PrivateHeader = 0x1,
102     /// \brief This header is part of the module (for layering purposes) but
103     /// should be textually included.
104     TextualHeader = 0x2,
105     // Caution: Adding an enumerator needs other changes.
106     // Adjust the number of bits for KnownHeader::Storage.
107     // Adjust the bitfield HeaderFileInfo::HeaderRole size.
108     // Adjust the HeaderFileInfoTrait::ReadData streaming.
109     // Adjust the HeaderFileInfoTrait::EmitData streaming.
110     // Adjust ModuleMap::addHeader.
111   };
112 
113   /// \brief A header that is known to reside within a given module,
114   /// whether it was included or excluded.
115   class KnownHeader {
116     llvm::PointerIntPair<Module *, 2, ModuleHeaderRole> Storage;
117 
118   public:
KnownHeader()119     KnownHeader() : Storage(nullptr, NormalHeader) { }
KnownHeader(Module * M,ModuleHeaderRole Role)120     KnownHeader(Module *M, ModuleHeaderRole Role) : Storage(M, Role) { }
121 
122     friend bool operator==(const KnownHeader &A, const KnownHeader &B) {
123       return A.Storage == B.Storage;
124     }
125     friend bool operator!=(const KnownHeader &A, const KnownHeader &B) {
126       return A.Storage != B.Storage;
127     }
128 
129     /// \brief Retrieve the module the header is stored in.
getModule()130     Module *getModule() const { return Storage.getPointer(); }
131 
132     /// \brief The role of this header within the module.
getRole()133     ModuleHeaderRole getRole() const { return Storage.getInt(); }
134 
135     /// \brief Whether this header is available in the module.
isAvailable()136     bool isAvailable() const {
137       return getModule()->isAvailable();
138     }
139 
140     /// \brief Whether this header is accessible from the specified module.
isAccessibleFrom(Module * M)141     bool isAccessibleFrom(Module *M) const {
142       return !(getRole() & PrivateHeader) ||
143              (M && M->getTopLevelModule() == getModule()->getTopLevelModule());
144     }
145 
146     // \brief Whether this known header is valid (i.e., it has an
147     // associated module).
148     explicit operator bool() const {
149       return Storage.getPointer() != nullptr;
150     }
151   };
152 
153   typedef llvm::SmallPtrSet<const FileEntry *, 1> AdditionalModMapsSet;
154 
155 private:
156   typedef llvm::DenseMap<const FileEntry *, SmallVector<KnownHeader, 1> >
157   HeadersMap;
158 
159   /// \brief Mapping from each header to the module that owns the contents of
160   /// that header.
161   HeadersMap Headers;
162 
163   /// \brief Mapping from directories with umbrella headers to the module
164   /// that is generated from the umbrella header.
165   ///
166   /// This mapping is used to map headers that haven't explicitly been named
167   /// in the module map over to the module that includes them via its umbrella
168   /// header.
169   llvm::DenseMap<const DirectoryEntry *, Module *> UmbrellaDirs;
170 
171   /// \brief The set of attributes that can be attached to a module.
172   struct Attributes {
AttributesAttributes173     Attributes() : IsSystem(), IsExternC(), IsExhaustive() {}
174 
175     /// \brief Whether this is a system module.
176     unsigned IsSystem : 1;
177 
178     /// \brief Whether this is an extern "C" module.
179     unsigned IsExternC : 1;
180 
181     /// \brief Whether this is an exhaustive set of configuration macros.
182     unsigned IsExhaustive : 1;
183   };
184 
185   /// \brief A directory for which framework modules can be inferred.
186   struct InferredDirectory {
InferredDirectoryInferredDirectory187     InferredDirectory() : InferModules() {}
188 
189     /// \brief Whether to infer modules from this directory.
190     unsigned InferModules : 1;
191 
192     /// \brief The attributes to use for inferred modules.
193     Attributes Attrs;
194 
195     /// \brief If \c InferModules is non-zero, the module map file that allowed
196     /// inferred modules.  Otherwise, nullptr.
197     const FileEntry *ModuleMapFile;
198 
199     /// \brief The names of modules that cannot be inferred within this
200     /// directory.
201     SmallVector<std::string, 2> ExcludedModules;
202   };
203 
204   /// \brief A mapping from directories to information about inferring
205   /// framework modules from within those directories.
206   llvm::DenseMap<const DirectoryEntry *, InferredDirectory> InferredDirectories;
207 
208   /// A mapping from an inferred module to the module map that allowed the
209   /// inference.
210   llvm::DenseMap<const Module *, const FileEntry *> InferredModuleAllowedBy;
211 
212   llvm::DenseMap<const Module *, AdditionalModMapsSet> AdditionalModMaps;
213 
214   /// \brief Describes whether we haved parsed a particular file as a module
215   /// map.
216   llvm::DenseMap<const FileEntry *, bool> ParsedModuleMap;
217 
218   friend class ModuleMapParser;
219 
220   /// \brief Resolve the given export declaration into an actual export
221   /// declaration.
222   ///
223   /// \param Mod The module in which we're resolving the export declaration.
224   ///
225   /// \param Unresolved The export declaration to resolve.
226   ///
227   /// \param Complain Whether this routine should complain about unresolvable
228   /// exports.
229   ///
230   /// \returns The resolved export declaration, which will have a NULL pointer
231   /// if the export could not be resolved.
232   Module::ExportDecl
233   resolveExport(Module *Mod, const Module::UnresolvedExportDecl &Unresolved,
234                 bool Complain) const;
235 
236   /// \brief Resolve the given module id to an actual module.
237   ///
238   /// \param Id The module-id to resolve.
239   ///
240   /// \param Mod The module in which we're resolving the module-id.
241   ///
242   /// \param Complain Whether this routine should complain about unresolvable
243   /// module-ids.
244   ///
245   /// \returns The resolved module, or null if the module-id could not be
246   /// resolved.
247   Module *resolveModuleId(const ModuleId &Id, Module *Mod, bool Complain) const;
248 
249   /// \brief Looks up the modules that \p File corresponds to.
250   ///
251   /// If \p File represents a builtin header within Clang's builtin include
252   /// directory, this also loads all of the module maps to see if it will get
253   /// associated with a specific module (e.g. in /usr/include).
254   HeadersMap::iterator findKnownHeader(const FileEntry *File);
255 
256   /// \brief Searches for a module whose umbrella directory contains \p File.
257   ///
258   /// \param File The header to search for.
259   ///
260   /// \param IntermediateDirs On success, contains the set of directories
261   /// searched before finding \p File.
262   KnownHeader findHeaderInUmbrellaDirs(const FileEntry *File,
263                     SmallVectorImpl<const DirectoryEntry *> &IntermediateDirs);
264 
265   /// \brief Given that \p File is not in the Headers map, look it up within
266   /// umbrella directories and find or create a module for it.
267   KnownHeader findOrCreateModuleForHeaderInUmbrellaDir(const FileEntry *File);
268 
269   /// \brief A convenience method to determine if \p File is (possibly nested)
270   /// in an umbrella directory.
isHeaderInUmbrellaDirs(const FileEntry * File)271   bool isHeaderInUmbrellaDirs(const FileEntry *File) {
272     SmallVector<const DirectoryEntry *, 2> IntermediateDirs;
273     return static_cast<bool>(findHeaderInUmbrellaDirs(File, IntermediateDirs));
274   }
275 
276   Module *inferFrameworkModule(const DirectoryEntry *FrameworkDir,
277                                Attributes Attrs, Module *Parent);
278 
279 public:
280   /// \brief Construct a new module map.
281   ///
282   /// \param SourceMgr The source manager used to find module files and headers.
283   /// This source manager should be shared with the header-search mechanism,
284   /// since they will refer to the same headers.
285   ///
286   /// \param Diags A diagnostic engine used for diagnostics.
287   ///
288   /// \param LangOpts Language options for this translation unit.
289   ///
290   /// \param Target The target for this translation unit.
291   ModuleMap(SourceManager &SourceMgr, DiagnosticsEngine &Diags,
292             const LangOptions &LangOpts, const TargetInfo *Target,
293             HeaderSearch &HeaderInfo);
294 
295   /// \brief Destroy the module map.
296   ///
297   ~ModuleMap();
298 
299   /// \brief Set the target information.
300   void setTarget(const TargetInfo &Target);
301 
302   /// \brief Set the directory that contains Clang-supplied include
303   /// files, such as our stdarg.h or tgmath.h.
setBuiltinIncludeDir(const DirectoryEntry * Dir)304   void setBuiltinIncludeDir(const DirectoryEntry *Dir) {
305     BuiltinIncludeDir = Dir;
306   }
307 
308   /// \brief Add a module map callback.
addModuleMapCallbacks(std::unique_ptr<ModuleMapCallbacks> Callback)309   void addModuleMapCallbacks(std::unique_ptr<ModuleMapCallbacks> Callback) {
310     Callbacks.push_back(std::move(Callback));
311   }
312 
313   /// \brief Retrieve the module that owns the given header file, if any.
314   ///
315   /// \param File The header file that is likely to be included.
316   ///
317   /// \returns The module KnownHeader, which provides the module that owns the
318   /// given header file.  The KnownHeader is default constructed to indicate
319   /// that no module owns this header file.
320   KnownHeader findModuleForHeader(const FileEntry *File);
321 
322   /// \brief Retrieve all the modules that contain the given header file. This
323   /// may not include umbrella modules, nor information from external sources,
324   /// if they have not yet been inferred / loaded.
325   ///
326   /// Typically, \ref findModuleForHeader should be used instead, as it picks
327   /// the preferred module for the header.
328   ArrayRef<KnownHeader> findAllModulesForHeader(const FileEntry *File) const;
329 
330   /// \brief Reports errors if a module must not include a specific file.
331   ///
332   /// \param RequestingModule The module including a file.
333   ///
334   /// \param RequestingModuleIsModuleInterface \c true if the inclusion is in
335   ///        the interface of RequestingModule, \c false if it's in the
336   ///        implementation of RequestingModule. Value is ignored and
337   ///        meaningless if RequestingModule is nullptr.
338   ///
339   /// \param FilenameLoc The location of the inclusion's filename.
340   ///
341   /// \param Filename The included filename as written.
342   ///
343   /// \param File The included file.
344   void diagnoseHeaderInclusion(Module *RequestingModule,
345                                bool RequestingModuleIsModuleInterface,
346                                SourceLocation FilenameLoc, StringRef Filename,
347                                const FileEntry *File);
348 
349   /// \brief Determine whether the given header is part of a module
350   /// marked 'unavailable'.
351   bool isHeaderInUnavailableModule(const FileEntry *Header) const;
352 
353   /// \brief Determine whether the given header is unavailable as part
354   /// of the specified module.
355   bool isHeaderUnavailableInModule(const FileEntry *Header,
356                                    const Module *RequestingModule) const;
357 
358   /// \brief Retrieve a module with the given name.
359   ///
360   /// \param Name The name of the module to look up.
361   ///
362   /// \returns The named module, if known; otherwise, returns null.
363   Module *findModule(StringRef Name) const;
364 
365   /// \brief Retrieve a module with the given name using lexical name lookup,
366   /// starting at the given context.
367   ///
368   /// \param Name The name of the module to look up.
369   ///
370   /// \param Context The module context, from which we will perform lexical
371   /// name lookup.
372   ///
373   /// \returns The named module, if known; otherwise, returns null.
374   Module *lookupModuleUnqualified(StringRef Name, Module *Context) const;
375 
376   /// \brief Retrieve a module with the given name within the given context,
377   /// using direct (qualified) name lookup.
378   ///
379   /// \param Name The name of the module to look up.
380   ///
381   /// \param Context The module for which we will look for a submodule. If
382   /// null, we will look for a top-level module.
383   ///
384   /// \returns The named submodule, if known; otherwose, returns null.
385   Module *lookupModuleQualified(StringRef Name, Module *Context) const;
386 
387   /// \brief Find a new module or submodule, or create it if it does not already
388   /// exist.
389   ///
390   /// \param Name The name of the module to find or create.
391   ///
392   /// \param Parent The module that will act as the parent of this submodule,
393   /// or NULL to indicate that this is a top-level module.
394   ///
395   /// \param IsFramework Whether this is a framework module.
396   ///
397   /// \param IsExplicit Whether this is an explicit submodule.
398   ///
399   /// \returns The found or newly-created module, along with a boolean value
400   /// that will be true if the module is newly-created.
401   std::pair<Module *, bool> findOrCreateModule(StringRef Name, Module *Parent,
402                                                bool IsFramework,
403                                                bool IsExplicit);
404 
405   /// \brief Infer the contents of a framework module map from the given
406   /// framework directory.
407   Module *inferFrameworkModule(const DirectoryEntry *FrameworkDir,
408                                bool IsSystem, Module *Parent);
409 
410   /// \brief Retrieve the module map file containing the definition of the given
411   /// module.
412   ///
413   /// \param Module The module whose module map file will be returned, if known.
414   ///
415   /// \returns The file entry for the module map file containing the given
416   /// module, or NULL if the module definition was inferred.
417   const FileEntry *getContainingModuleMapFile(const Module *Module) const;
418 
419   /// \brief Get the module map file that (along with the module name) uniquely
420   /// identifies this module.
421   ///
422   /// The particular module that \c Name refers to may depend on how the module
423   /// was found in header search. However, the combination of \c Name and
424   /// this module map will be globally unique for top-level modules. In the case
425   /// of inferred modules, returns the module map that allowed the inference
426   /// (e.g. contained 'module *'). Otherwise, returns
427   /// getContainingModuleMapFile().
428   const FileEntry *getModuleMapFileForUniquing(const Module *M) const;
429 
430   void setInferredModuleAllowedBy(Module *M, const FileEntry *ModuleMap);
431 
432   /// \brief Get any module map files other than getModuleMapFileForUniquing(M)
433   /// that define submodules of a top-level module \p M. This is cheaper than
434   /// getting the module map file for each submodule individually, since the
435   /// expected number of results is very small.
getAdditionalModuleMapFiles(const Module * M)436   AdditionalModMapsSet *getAdditionalModuleMapFiles(const Module *M) {
437     auto I = AdditionalModMaps.find(M);
438     if (I == AdditionalModMaps.end())
439       return nullptr;
440     return &I->second;
441   }
442 
addAdditionalModuleMapFile(const Module * M,const FileEntry * ModuleMap)443   void addAdditionalModuleMapFile(const Module *M, const FileEntry *ModuleMap) {
444     AdditionalModMaps[M].insert(ModuleMap);
445   }
446 
447   /// \brief Resolve all of the unresolved exports in the given module.
448   ///
449   /// \param Mod The module whose exports should be resolved.
450   ///
451   /// \param Complain Whether to emit diagnostics for failures.
452   ///
453   /// \returns true if any errors were encountered while resolving exports,
454   /// false otherwise.
455   bool resolveExports(Module *Mod, bool Complain);
456 
457   /// \brief Resolve all of the unresolved uses in the given module.
458   ///
459   /// \param Mod The module whose uses should be resolved.
460   ///
461   /// \param Complain Whether to emit diagnostics for failures.
462   ///
463   /// \returns true if any errors were encountered while resolving uses,
464   /// false otherwise.
465   bool resolveUses(Module *Mod, bool Complain);
466 
467   /// \brief Resolve all of the unresolved conflicts in the given module.
468   ///
469   /// \param Mod The module whose conflicts should be resolved.
470   ///
471   /// \param Complain Whether to emit diagnostics for failures.
472   ///
473   /// \returns true if any errors were encountered while resolving conflicts,
474   /// false otherwise.
475   bool resolveConflicts(Module *Mod, bool Complain);
476 
477   /// \brief Infers the (sub)module based on the given source location and
478   /// source manager.
479   ///
480   /// \param Loc The location within the source that we are querying, along
481   /// with its source manager.
482   ///
483   /// \returns The module that owns this source location, or null if no
484   /// module owns this source location.
485   Module *inferModuleFromLocation(FullSourceLoc Loc);
486 
487   /// \brief Sets the umbrella header of the given module to the given
488   /// header.
489   void setUmbrellaHeader(Module *Mod, const FileEntry *UmbrellaHeader,
490                          Twine NameAsWritten);
491 
492   /// \brief Sets the umbrella directory of the given module to the given
493   /// directory.
494   void setUmbrellaDir(Module *Mod, const DirectoryEntry *UmbrellaDir,
495                       Twine NameAsWritten);
496 
497   /// \brief Adds this header to the given module.
498   /// \param Role The role of the header wrt the module.
499   void addHeader(Module *Mod, Module::Header Header,
500                  ModuleHeaderRole Role, bool Imported = false);
501 
502   /// \brief Marks this header as being excluded from the given module.
503   void excludeHeader(Module *Mod, Module::Header Header);
504 
505   /// \brief Parse the given module map file, and record any modules we
506   /// encounter.
507   ///
508   /// \param File The file to be parsed.
509   ///
510   /// \param IsSystem Whether this module map file is in a system header
511   /// directory, and therefore should be considered a system module.
512   ///
513   /// \param HomeDir The directory in which relative paths within this module
514   ///        map file will be resolved.
515   ///
516   /// \param ExternModuleLoc The location of the "extern module" declaration
517   ///        that caused us to load this module map file, if any.
518   ///
519   /// \returns true if an error occurred, false otherwise.
520   bool parseModuleMapFile(const FileEntry *File, bool IsSystem,
521                           const DirectoryEntry *HomeDir,
522                           SourceLocation ExternModuleLoc = SourceLocation());
523 
524   /// \brief Dump the contents of the module map, for debugging purposes.
525   void dump();
526 
527   typedef llvm::StringMap<Module *>::const_iterator module_iterator;
module_begin()528   module_iterator module_begin() const { return Modules.begin(); }
module_end()529   module_iterator module_end()   const { return Modules.end(); }
530 };
531 
532 }
533 #endif
534