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 class ModuleMap {
40   SourceManager &SourceMgr;
41   DiagnosticsEngine &Diags;
42   const LangOptions &LangOpts;
43   const TargetInfo *Target;
44   HeaderSearch &HeaderInfo;
45 
46   /// \brief The directory used for Clang-supplied, builtin include headers,
47   /// such as "stdint.h".
48   const DirectoryEntry *BuiltinIncludeDir;
49 
50   /// \brief Language options used to parse the module map itself.
51   ///
52   /// These are always simple C language options.
53   LangOptions MMapLangOpts;
54 
55   // The module that we are building; related to \c LangOptions::CurrentModule.
56   Module *CompilingModule;
57 
58 public:
59   // The module that the .cc source file is associated with.
60   Module *SourceModule;
61   std::string SourceModuleName;
62 
63 private:
64   /// \brief The top-level modules that are known.
65   llvm::StringMap<Module *> Modules;
66 
67 public:
68   /// \brief Describes the role of a module header.
69   enum ModuleHeaderRole {
70     /// \brief This header is normally included in the module.
71     NormalHeader,
72     /// \brief This header is included but private.
73     PrivateHeader,
74     /// \brief This header is explicitly excluded from the module.
75     ExcludedHeader
76     // Caution: Adding an enumerator needs other changes.
77     // Adjust the number of bits for KnownHeader::Storage.
78     // Adjust the bitfield HeaderFileInfo::HeaderRole size.
79     // Adjust the HeaderFileInfoTrait::ReadData streaming.
80     // Adjust the HeaderFileInfoTrait::EmitData streaming.
81   };
82 
83   /// \brief A header that is known to reside within a given module,
84   /// whether it was included or excluded.
85   class KnownHeader {
86     llvm::PointerIntPair<Module *, 2, ModuleHeaderRole> Storage;
87 
88   public:
89     KnownHeader() : Storage(0, NormalHeader) { }
90     KnownHeader(Module *M, ModuleHeaderRole Role) : Storage(M, Role) { }
91 
92     /// \brief Retrieve the module the header is stored in.
93     Module *getModule() const { return Storage.getPointer(); }
94 
95     /// \brief The role of this header within the module.
96     ModuleHeaderRole getRole() const { return Storage.getInt(); }
97 
98     /// \brief Whether this header is available in the module.
99     bool isAvailable() const {
100       return getRole() != ExcludedHeader && getModule()->isAvailable();
101     }
102 
103     // \brief Whether this known header is valid (i.e., it has an
104     // associated module).
105     LLVM_EXPLICIT operator bool() const { return Storage.getPointer() != 0; }
106   };
107 
108 private:
109   typedef llvm::DenseMap<const FileEntry *, SmallVector<KnownHeader, 1> >
110   HeadersMap;
111 
112   /// \brief Mapping from each header to the module that owns the contents of
113   /// that header.
114   HeadersMap Headers;
115 
116   /// \brief Mapping from directories with umbrella headers to the module
117   /// that is generated from the umbrella header.
118   ///
119   /// This mapping is used to map headers that haven't explicitly been named
120   /// in the module map over to the module that includes them via its umbrella
121   /// header.
122   llvm::DenseMap<const DirectoryEntry *, Module *> UmbrellaDirs;
123 
124   /// \brief A directory for which framework modules can be inferred.
125   struct InferredDirectory {
126     InferredDirectory() : InferModules(), InferSystemModules() { }
127 
128     /// \brief Whether to infer modules from this directory.
129     unsigned InferModules : 1;
130 
131     /// \brief Whether the modules we infer are [system] modules.
132     unsigned InferSystemModules : 1;
133 
134     /// \brief The names of modules that cannot be inferred within this
135     /// directory.
136     SmallVector<std::string, 2> ExcludedModules;
137   };
138 
139   /// \brief A mapping from directories to information about inferring
140   /// framework modules from within those directories.
141   llvm::DenseMap<const DirectoryEntry *, InferredDirectory> InferredDirectories;
142 
143   /// \brief Describes whether we haved parsed a particular file as a module
144   /// map.
145   llvm::DenseMap<const FileEntry *, bool> ParsedModuleMap;
146 
147   friend class ModuleMapParser;
148 
149   /// \brief Resolve the given export declaration into an actual export
150   /// declaration.
151   ///
152   /// \param Mod The module in which we're resolving the export declaration.
153   ///
154   /// \param Unresolved The export declaration to resolve.
155   ///
156   /// \param Complain Whether this routine should complain about unresolvable
157   /// exports.
158   ///
159   /// \returns The resolved export declaration, which will have a NULL pointer
160   /// if the export could not be resolved.
161   Module::ExportDecl
162   resolveExport(Module *Mod, const Module::UnresolvedExportDecl &Unresolved,
163                 bool Complain) const;
164 
165   /// \brief Resolve the given module id to an actual module.
166   ///
167   /// \param Id The module-id to resolve.
168   ///
169   /// \param Mod The module in which we're resolving the module-id.
170   ///
171   /// \param Complain Whether this routine should complain about unresolvable
172   /// module-ids.
173   ///
174   /// \returns The resolved module, or null if the module-id could not be
175   /// resolved.
176   Module *resolveModuleId(const ModuleId &Id, Module *Mod, bool Complain) const;
177 
178   /// \brief Looks up the modules that \p File corresponds to.
179   ///
180   /// If \p File represents a builtin header within Clang's builtin include
181   /// directory, this also loads all of the module maps to see if it will get
182   /// associated with a specific module (e.g. in /usr/include).
183   HeadersMap::iterator findKnownHeader(const FileEntry *File);
184 
185 public:
186   /// \brief Construct a new module map.
187   ///
188   /// \param SourceMgr The source manager used to find module files and headers.
189   /// This source manager should be shared with the header-search mechanism,
190   /// since they will refer to the same headers.
191   ///
192   /// \param Diags A diagnostic engine used for diagnostics.
193   ///
194   /// \param LangOpts Language options for this translation unit.
195   ///
196   /// \param Target The target for this translation unit.
197   ModuleMap(SourceManager &SourceMgr, DiagnosticsEngine &Diags,
198             const LangOptions &LangOpts, const TargetInfo *Target,
199             HeaderSearch &HeaderInfo);
200 
201   /// \brief Destroy the module map.
202   ///
203   ~ModuleMap();
204 
205   /// \brief Set the target information.
206   void setTarget(const TargetInfo &Target);
207 
208   /// \brief Set the directory that contains Clang-supplied include
209   /// files, such as our stdarg.h or tgmath.h.
210   void setBuiltinIncludeDir(const DirectoryEntry *Dir) {
211     BuiltinIncludeDir = Dir;
212   }
213 
214   /// \brief Retrieve the module that owns the given header file, if any.
215   ///
216   /// \param File The header file that is likely to be included.
217   ///
218   /// \param RequestingModule Specifies the module the header is intended to be
219   /// used from.  Used to disambiguate if a header is present in multiple
220   /// modules.
221   ///
222   /// \returns The module KnownHeader, which provides the module that owns the
223   /// given header file.  The KnownHeader is default constructed to indicate
224   /// that no module owns this header file.
225   KnownHeader findModuleForHeader(const FileEntry *File,
226                                   Module *RequestingModule = NULL);
227 
228   /// \brief Reports errors if a module must not include a specific file.
229   ///
230   /// \param RequestingModule The module including a file.
231   ///
232   /// \param FilenameLoc The location of the inclusion's filename.
233   ///
234   /// \param Filename The included filename as written.
235   ///
236   /// \param File The included file.
237   void diagnoseHeaderInclusion(Module *RequestingModule,
238                                SourceLocation FilenameLoc, StringRef Filename,
239                                const FileEntry *File);
240 
241   /// \brief Determine whether the given header is part of a module
242   /// marked 'unavailable'.
243   bool isHeaderInUnavailableModule(const FileEntry *Header) const;
244 
245   /// \brief Retrieve a module with the given name.
246   ///
247   /// \param Name The name of the module to look up.
248   ///
249   /// \returns The named module, if known; otherwise, returns null.
250   Module *findModule(StringRef Name) const;
251 
252   /// \brief Retrieve a module with the given name using lexical name lookup,
253   /// starting at the given context.
254   ///
255   /// \param Name The name of the module to look up.
256   ///
257   /// \param Context The module context, from which we will perform lexical
258   /// name lookup.
259   ///
260   /// \returns The named module, if known; otherwise, returns null.
261   Module *lookupModuleUnqualified(StringRef Name, Module *Context) const;
262 
263   /// \brief Retrieve a module with the given name within the given context,
264   /// using direct (qualified) name lookup.
265   ///
266   /// \param Name The name of the module to look up.
267   ///
268   /// \param Context The module for which we will look for a submodule. If
269   /// null, we will look for a top-level module.
270   ///
271   /// \returns The named submodule, if known; otherwose, returns null.
272   Module *lookupModuleQualified(StringRef Name, Module *Context) const;
273 
274   /// \brief Find a new module or submodule, or create it if it does not already
275   /// exist.
276   ///
277   /// \param Name The name of the module to find or create.
278   ///
279   /// \param Parent The module that will act as the parent of this submodule,
280   /// or NULL to indicate that this is a top-level module.
281   ///
282   /// \param IsFramework Whether this is a framework module.
283   ///
284   /// \param IsExplicit Whether this is an explicit submodule.
285   ///
286   /// \returns The found or newly-created module, along with a boolean value
287   /// that will be true if the module is newly-created.
288   std::pair<Module *, bool> findOrCreateModule(StringRef Name, Module *Parent,
289                                                bool IsFramework,
290                                                bool IsExplicit);
291 
292   /// \brief Determine whether we can infer a framework module a framework
293   /// with the given name in the given
294   ///
295   /// \param ParentDir The directory that is the parent of the framework
296   /// directory.
297   ///
298   /// \param Name The name of the module.
299   ///
300   /// \param IsSystem Will be set to 'true' if the inferred module must be a
301   /// system module.
302   ///
303   /// \returns true if we are allowed to infer a framework module, and false
304   /// otherwise.
305   bool canInferFrameworkModule(const DirectoryEntry *ParentDir,
306                                StringRef Name, bool &IsSystem) const;
307 
308   /// \brief Infer the contents of a framework module map from the given
309   /// framework directory.
310   Module *inferFrameworkModule(StringRef ModuleName,
311                                const DirectoryEntry *FrameworkDir,
312                                bool IsSystem, Module *Parent);
313 
314   /// \brief Retrieve the module map file containing the definition of the given
315   /// module.
316   ///
317   /// \param Module The module whose module map file will be returned, if known.
318   ///
319   /// \returns The file entry for the module map file containing the given
320   /// module, or NULL if the module definition was inferred.
321   const FileEntry *getContainingModuleMapFile(Module *Module) const;
322 
323   /// \brief Resolve all of the unresolved exports in the given module.
324   ///
325   /// \param Mod The module whose exports should be resolved.
326   ///
327   /// \param Complain Whether to emit diagnostics for failures.
328   ///
329   /// \returns true if any errors were encountered while resolving exports,
330   /// false otherwise.
331   bool resolveExports(Module *Mod, bool Complain);
332 
333   /// \brief Resolve all of the unresolved uses in the given module.
334   ///
335   /// \param Mod The module whose uses should be resolved.
336   ///
337   /// \param Complain Whether to emit diagnostics for failures.
338   ///
339   /// \returns true if any errors were encountered while resolving uses,
340   /// false otherwise.
341   bool resolveUses(Module *Mod, bool Complain);
342 
343   /// \brief Resolve all of the unresolved conflicts in the given module.
344   ///
345   /// \param Mod The module whose conflicts should be resolved.
346   ///
347   /// \param Complain Whether to emit diagnostics for failures.
348   ///
349   /// \returns true if any errors were encountered while resolving conflicts,
350   /// false otherwise.
351   bool resolveConflicts(Module *Mod, bool Complain);
352 
353   /// \brief Infers the (sub)module based on the given source location and
354   /// source manager.
355   ///
356   /// \param Loc The location within the source that we are querying, along
357   /// with its source manager.
358   ///
359   /// \returns The module that owns this source location, or null if no
360   /// module owns this source location.
361   Module *inferModuleFromLocation(FullSourceLoc Loc);
362 
363   /// \brief Sets the umbrella header of the given module to the given
364   /// header.
365   void setUmbrellaHeader(Module *Mod, const FileEntry *UmbrellaHeader);
366 
367   /// \brief Sets the umbrella directory of the given module to the given
368   /// directory.
369   void setUmbrellaDir(Module *Mod, const DirectoryEntry *UmbrellaDir);
370 
371   /// \brief Adds this header to the given module.
372   /// \param Role The role of the header wrt the module.
373   void addHeader(Module *Mod, const FileEntry *Header,
374                  ModuleHeaderRole Role);
375 
376   /// \brief Parse the given module map file, and record any modules we
377   /// encounter.
378   ///
379   /// \param File The file to be parsed.
380   ///
381   /// \param IsSystem Whether this module map file is in a system header
382   /// directory, and therefore should be considered a system module.
383   ///
384   /// \returns true if an error occurred, false otherwise.
385   bool parseModuleMapFile(const FileEntry *File, bool IsSystem);
386 
387   /// \brief Dump the contents of the module map, for debugging purposes.
388   void dump();
389 
390   typedef llvm::StringMap<Module *>::const_iterator module_iterator;
391   module_iterator module_begin() const { return Modules.begin(); }
392   module_iterator module_end()   const { return Modules.end(); }
393 };
394 
395 }
396 #endif
397