1 //===--- ModuleManager.cpp - Module Manager ---------------------*- 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 ModuleManager class, which manages a set of loaded 11 // modules for the ASTReader. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_SERIALIZATION_MODULEMANAGER_H 16 #define LLVM_CLANG_SERIALIZATION_MODULEMANAGER_H 17 18 #include "clang/Basic/FileManager.h" 19 #include "clang/Serialization/Module.h" 20 #include "llvm/ADT/DenseMap.h" 21 #include "llvm/ADT/SmallPtrSet.h" 22 23 namespace clang { 24 25 class GlobalModuleIndex; 26 class ModuleMap; 27 28 namespace serialization { 29 30 /// \brief Manages the set of modules loaded by an AST reader. 31 class ModuleManager { 32 /// \brief The chain of AST files. The first entry is the one named by the 33 /// user, the last one is the one that doesn't depend on anything further. 34 SmallVector<ModuleFile *, 2> Chain; 35 36 /// \brief All loaded modules, indexed by name. 37 llvm::DenseMap<const FileEntry *, ModuleFile *> Modules; 38 39 /// \brief FileManager that handles translating between filenames and 40 /// FileEntry *. 41 FileManager &FileMgr; 42 43 /// \brief A lookup of in-memory (virtual file) buffers 44 llvm::DenseMap<const FileEntry *, std::unique_ptr<llvm::MemoryBuffer>> 45 InMemoryBuffers; 46 47 /// \brief The visitation order. 48 SmallVector<ModuleFile *, 4> VisitOrder; 49 50 /// \brief The list of module files that both we and the global module index 51 /// know about. 52 /// 53 /// Either the global index or the module manager may have modules that the 54 /// other does not know about, because the global index can be out-of-date 55 /// (in which case the module manager could have modules it does not) and 56 /// this particular translation unit might not have loaded all of the modules 57 /// known to the global index. 58 SmallVector<ModuleFile *, 4> ModulesInCommonWithGlobalIndex; 59 60 /// \brief The global module index, if one is attached. 61 /// 62 /// The global module index will actually be owned by the ASTReader; this is 63 /// just an non-owning pointer. 64 GlobalModuleIndex *GlobalIndex; 65 66 /// \brief State used by the "visit" operation to avoid malloc traffic in 67 /// calls to visit(). 68 struct VisitState { VisitStateVisitState69 explicit VisitState(unsigned N) 70 : VisitNumber(N, 0), NextVisitNumber(1), NextState(nullptr) 71 { 72 Stack.reserve(N); 73 } 74 ~VisitStateVisitState75 ~VisitState() { 76 delete NextState; 77 } 78 79 /// \brief The stack used when marking the imports of a particular module 80 /// as not-to-be-visited. 81 SmallVector<ModuleFile *, 4> Stack; 82 83 /// \brief The visit number of each module file, which indicates when 84 /// this module file was last visited. 85 SmallVector<unsigned, 4> VisitNumber; 86 87 /// \brief The next visit number to use to mark visited module files. 88 unsigned NextVisitNumber; 89 90 /// \brief The next visit state. 91 VisitState *NextState; 92 }; 93 94 /// \brief The first visit() state in the chain. 95 VisitState *FirstVisitState; 96 97 VisitState *allocateVisitState(); 98 void returnVisitState(VisitState *State); 99 100 public: 101 typedef SmallVectorImpl<ModuleFile*>::iterator ModuleIterator; 102 typedef SmallVectorImpl<ModuleFile*>::const_iterator ModuleConstIterator; 103 typedef SmallVectorImpl<ModuleFile*>::reverse_iterator ModuleReverseIterator; 104 typedef std::pair<uint32_t, StringRef> ModuleOffset; 105 106 explicit ModuleManager(FileManager &FileMgr); 107 ~ModuleManager(); 108 109 /// \brief Forward iterator to traverse all loaded modules. This is reverse 110 /// source-order. begin()111 ModuleIterator begin() { return Chain.begin(); } 112 /// \brief Forward iterator end-point to traverse all loaded modules end()113 ModuleIterator end() { return Chain.end(); } 114 115 /// \brief Const forward iterator to traverse all loaded modules. This is 116 /// in reverse source-order. begin()117 ModuleConstIterator begin() const { return Chain.begin(); } 118 /// \brief Const forward iterator end-point to traverse all loaded modules end()119 ModuleConstIterator end() const { return Chain.end(); } 120 121 /// \brief Reverse iterator to traverse all loaded modules. This is in 122 /// source order. rbegin()123 ModuleReverseIterator rbegin() { return Chain.rbegin(); } 124 /// \brief Reverse iterator end-point to traverse all loaded modules. rend()125 ModuleReverseIterator rend() { return Chain.rend(); } 126 127 /// \brief Returns the primary module associated with the manager, that is, 128 /// the first module loaded getPrimaryModule()129 ModuleFile &getPrimaryModule() { return *Chain[0]; } 130 131 /// \brief Returns the primary module associated with the manager, that is, 132 /// the first module loaded. getPrimaryModule()133 ModuleFile &getPrimaryModule() const { return *Chain[0]; } 134 135 /// \brief Returns the module associated with the given index 136 ModuleFile &operator[](unsigned Index) const { return *Chain[Index]; } 137 138 /// \brief Returns the module associated with the given name 139 ModuleFile *lookup(StringRef Name); 140 141 /// \brief Returns the module associated with the given module file. 142 ModuleFile *lookup(const FileEntry *File); 143 144 /// \brief Returns the in-memory (virtual file) buffer with the given name 145 std::unique_ptr<llvm::MemoryBuffer> lookupBuffer(StringRef Name); 146 147 /// \brief Number of modules loaded size()148 unsigned size() const { return Chain.size(); } 149 150 /// \brief The result of attempting to add a new module. 151 enum AddModuleResult { 152 /// \brief The module file had already been loaded. 153 AlreadyLoaded, 154 /// \brief The module file was just loaded in response to this call. 155 NewlyLoaded, 156 /// \brief The module file is missing. 157 Missing, 158 /// \brief The module file is out-of-date. 159 OutOfDate 160 }; 161 162 /// \brief Attempts to create a new module and add it to the list of known 163 /// modules. 164 /// 165 /// \param FileName The file name of the module to be loaded. 166 /// 167 /// \param Type The kind of module being loaded. 168 /// 169 /// \param ImportLoc The location at which the module is imported. 170 /// 171 /// \param ImportedBy The module that is importing this module, or NULL if 172 /// this module is imported directly by the user. 173 /// 174 /// \param Generation The generation in which this module was loaded. 175 /// 176 /// \param ExpectedSize The expected size of the module file, used for 177 /// validation. This will be zero if unknown. 178 /// 179 /// \param ExpectedModTime The expected modification time of the module 180 /// file, used for validation. This will be zero if unknown. 181 /// 182 /// \param ExpectedSignature The expected signature of the module file, used 183 /// for validation. This will be zero if unknown. 184 /// 185 /// \param ReadSignature Reads the signature from an AST file without actually 186 /// loading it. 187 /// 188 /// \param Module A pointer to the module file if the module was successfully 189 /// loaded. 190 /// 191 /// \param ErrorStr Will be set to a non-empty string if any errors occurred 192 /// while trying to load the module. 193 /// 194 /// \return A pointer to the module that corresponds to this file name, 195 /// and a value indicating whether the module was loaded. 196 AddModuleResult addModule(StringRef FileName, ModuleKind Type, 197 SourceLocation ImportLoc, 198 ModuleFile *ImportedBy, unsigned Generation, 199 off_t ExpectedSize, time_t ExpectedModTime, 200 ASTFileSignature ExpectedSignature, 201 std::function<ASTFileSignature(llvm::BitstreamReader &)> 202 ReadSignature, 203 ModuleFile *&Module, 204 std::string &ErrorStr); 205 206 /// \brief Remove the given set of modules. 207 void removeModules(ModuleIterator first, ModuleIterator last, 208 llvm::SmallPtrSetImpl<ModuleFile *> &LoadedSuccessfully, 209 ModuleMap *modMap); 210 211 /// \brief Add an in-memory buffer the list of known buffers 212 void addInMemoryBuffer(StringRef FileName, 213 std::unique_ptr<llvm::MemoryBuffer> Buffer); 214 215 /// \brief Set the global module index. 216 void setGlobalIndex(GlobalModuleIndex *Index); 217 218 /// \brief Notification from the AST reader that the given module file 219 /// has been "accepted", and will not (can not) be unloaded. 220 void moduleFileAccepted(ModuleFile *MF); 221 222 /// \brief Visit each of the modules. 223 /// 224 /// This routine visits each of the modules, starting with the 225 /// "root" modules that no other loaded modules depend on, and 226 /// proceeding to the leaf modules, visiting each module only once 227 /// during the traversal. 228 /// 229 /// This traversal is intended to support various "lookup" 230 /// operations that can find data in any of the loaded modules. 231 /// 232 /// \param Visitor A visitor function that will be invoked with each 233 /// module and the given user data pointer. The return value must be 234 /// convertible to bool; when false, the visitation continues to 235 /// modules that the current module depends on. When true, the 236 /// visitation skips any modules that the current module depends on. 237 /// 238 /// \param UserData User data associated with the visitor object, which 239 /// will be passed along to the visitor. 240 /// 241 /// \param ModuleFilesHit If non-NULL, contains the set of module files 242 /// that we know we need to visit because the global module index told us to. 243 /// Any module that is known to both the global module index and the module 244 /// manager that is *not* in this set can be skipped. 245 void visit(bool (*Visitor)(ModuleFile &M, void *UserData), void *UserData, 246 llvm::SmallPtrSetImpl<ModuleFile *> *ModuleFilesHit = nullptr); 247 248 /// \brief Visit each of the modules with a depth-first traversal. 249 /// 250 /// This routine visits each of the modules known to the module 251 /// manager using a depth-first search, starting with the first 252 /// loaded module. The traversal invokes the callback both before 253 /// traversing the children (preorder traversal) and after 254 /// traversing the children (postorder traversal). 255 /// 256 /// \param Visitor A visitor function that will be invoked with each 257 /// module and given a \c Preorder flag that indicates whether we're 258 /// visiting the module before or after visiting its children. The 259 /// visitor may return true at any time to abort the depth-first 260 /// visitation. 261 /// 262 /// \param UserData User data ssociated with the visitor object, 263 /// which will be passed along to the user. 264 void visitDepthFirst(bool (*Visitor)(ModuleFile &M, bool Preorder, 265 void *UserData), 266 void *UserData); 267 268 /// \brief Attempt to resolve the given module file name to a file entry. 269 /// 270 /// \param FileName The name of the module file. 271 /// 272 /// \param ExpectedSize The size that the module file is expected to have. 273 /// If the actual size differs, the resolver should return \c true. 274 /// 275 /// \param ExpectedModTime The modification time that the module file is 276 /// expected to have. If the actual modification time differs, the resolver 277 /// should return \c true. 278 /// 279 /// \param File Will be set to the file if there is one, or null 280 /// otherwise. 281 /// 282 /// \returns True if a file exists but does not meet the size/ 283 /// modification time criteria, false if the file is either available and 284 /// suitable, or is missing. 285 bool lookupModuleFile(StringRef FileName, 286 off_t ExpectedSize, 287 time_t ExpectedModTime, 288 const FileEntry *&File); 289 290 /// \brief View the graphviz representation of the module graph. 291 void viewGraph(); 292 }; 293 294 } } // end namespace clang::serialization 295 296 #endif 297