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 class PCHContainerReader; 28 29 namespace serialization { 30 31 /// \brief Manages the set of modules loaded by an AST reader. 32 class ModuleManager { 33 /// \brief The chain of AST files, in the order in which we started to load 34 /// them (this order isn't really useful for anything). 35 SmallVector<ModuleFile *, 2> Chain; 36 37 /// \brief The chain of non-module PCH files. The first entry is the one named 38 /// by the user, the last one is the one that doesn't depend on anything 39 /// further. 40 SmallVector<ModuleFile *, 2> PCHChain; 41 42 // \brief The roots of the dependency DAG of AST files. This is used 43 // to implement short-circuiting logic when running DFS over the dependencies. 44 SmallVector<ModuleFile *, 2> Roots; 45 46 /// \brief All loaded modules, indexed by name. 47 llvm::DenseMap<const FileEntry *, ModuleFile *> Modules; 48 49 /// \brief FileManager that handles translating between filenames and 50 /// FileEntry *. 51 FileManager &FileMgr; 52 53 /// \brief Knows how to unwrap module containers. 54 const PCHContainerReader &PCHContainerRdr; 55 56 /// \brief A lookup of in-memory (virtual file) buffers 57 llvm::DenseMap<const FileEntry *, std::unique_ptr<llvm::MemoryBuffer>> 58 InMemoryBuffers; 59 60 /// \brief The visitation order. 61 SmallVector<ModuleFile *, 4> VisitOrder; 62 63 /// \brief The list of module files that both we and the global module index 64 /// know about. 65 /// 66 /// Either the global index or the module manager may have modules that the 67 /// other does not know about, because the global index can be out-of-date 68 /// (in which case the module manager could have modules it does not) and 69 /// this particular translation unit might not have loaded all of the modules 70 /// known to the global index. 71 SmallVector<ModuleFile *, 4> ModulesInCommonWithGlobalIndex; 72 73 /// \brief The global module index, if one is attached. 74 /// 75 /// The global module index will actually be owned by the ASTReader; this is 76 /// just an non-owning pointer. 77 GlobalModuleIndex *GlobalIndex; 78 79 /// \brief State used by the "visit" operation to avoid malloc traffic in 80 /// calls to visit(). 81 struct VisitState { VisitStateVisitState82 explicit VisitState(unsigned N) 83 : VisitNumber(N, 0), NextVisitNumber(1), NextState(nullptr) 84 { 85 Stack.reserve(N); 86 } 87 ~VisitStateVisitState88 ~VisitState() { 89 delete NextState; 90 } 91 92 /// \brief The stack used when marking the imports of a particular module 93 /// as not-to-be-visited. 94 SmallVector<ModuleFile *, 4> Stack; 95 96 /// \brief The visit number of each module file, which indicates when 97 /// this module file was last visited. 98 SmallVector<unsigned, 4> VisitNumber; 99 100 /// \brief The next visit number to use to mark visited module files. 101 unsigned NextVisitNumber; 102 103 /// \brief The next visit state. 104 VisitState *NextState; 105 }; 106 107 /// \brief The first visit() state in the chain. 108 VisitState *FirstVisitState; 109 110 VisitState *allocateVisitState(); 111 void returnVisitState(VisitState *State); 112 113 public: 114 typedef SmallVectorImpl<ModuleFile*>::iterator ModuleIterator; 115 typedef SmallVectorImpl<ModuleFile*>::const_iterator ModuleConstIterator; 116 typedef SmallVectorImpl<ModuleFile*>::reverse_iterator ModuleReverseIterator; 117 typedef std::pair<uint32_t, StringRef> ModuleOffset; 118 119 explicit ModuleManager(FileManager &FileMgr, 120 const PCHContainerReader &PCHContainerRdr); 121 ~ModuleManager(); 122 123 /// \brief Forward iterator to traverse all loaded modules. begin()124 ModuleIterator begin() { return Chain.begin(); } 125 /// \brief Forward iterator end-point to traverse all loaded modules end()126 ModuleIterator end() { return Chain.end(); } 127 128 /// \brief Const forward iterator to traverse all loaded modules. begin()129 ModuleConstIterator begin() const { return Chain.begin(); } 130 /// \brief Const forward iterator end-point to traverse all loaded modules end()131 ModuleConstIterator end() const { return Chain.end(); } 132 133 /// \brief Reverse iterator to traverse all loaded modules. rbegin()134 ModuleReverseIterator rbegin() { return Chain.rbegin(); } 135 /// \brief Reverse iterator end-point to traverse all loaded modules. rend()136 ModuleReverseIterator rend() { return Chain.rend(); } 137 138 /// \brief A range covering the PCH and preamble module files loaded. pch_modules()139 llvm::iterator_range<ModuleConstIterator> pch_modules() const { 140 return llvm::make_range(PCHChain.begin(), PCHChain.end()); 141 } 142 143 /// \brief Returns the primary module associated with the manager, that is, 144 /// the first module loaded getPrimaryModule()145 ModuleFile &getPrimaryModule() { return *Chain[0]; } 146 147 /// \brief Returns the primary module associated with the manager, that is, 148 /// the first module loaded. getPrimaryModule()149 ModuleFile &getPrimaryModule() const { return *Chain[0]; } 150 151 /// \brief Returns the module associated with the given index 152 ModuleFile &operator[](unsigned Index) const { return *Chain[Index]; } 153 154 /// \brief Returns the module associated with the given name 155 ModuleFile *lookup(StringRef Name); 156 157 /// \brief Returns the module associated with the given module file. 158 ModuleFile *lookup(const FileEntry *File); 159 160 /// \brief Returns the in-memory (virtual file) buffer with the given name 161 std::unique_ptr<llvm::MemoryBuffer> lookupBuffer(StringRef Name); 162 163 /// \brief Number of modules loaded size()164 unsigned size() const { return Chain.size(); } 165 166 /// \brief The result of attempting to add a new module. 167 enum AddModuleResult { 168 /// \brief The module file had already been loaded. 169 AlreadyLoaded, 170 /// \brief The module file was just loaded in response to this call. 171 NewlyLoaded, 172 /// \brief The module file is missing. 173 Missing, 174 /// \brief The module file is out-of-date. 175 OutOfDate 176 }; 177 178 typedef ASTFileSignature(*ASTFileSignatureReader)(llvm::BitstreamReader &); 179 180 /// \brief Attempts to create a new module and add it to the list of known 181 /// modules. 182 /// 183 /// \param FileName The file name of the module to be loaded. 184 /// 185 /// \param Type The kind of module being loaded. 186 /// 187 /// \param ImportLoc The location at which the module is imported. 188 /// 189 /// \param ImportedBy The module that is importing this module, or NULL if 190 /// this module is imported directly by the user. 191 /// 192 /// \param Generation The generation in which this module was loaded. 193 /// 194 /// \param ExpectedSize The expected size of the module file, used for 195 /// validation. This will be zero if unknown. 196 /// 197 /// \param ExpectedModTime The expected modification time of the module 198 /// file, used for validation. This will be zero if unknown. 199 /// 200 /// \param ExpectedSignature The expected signature of the module file, used 201 /// for validation. This will be zero if unknown. 202 /// 203 /// \param ReadSignature Reads the signature from an AST file without actually 204 /// loading it. 205 /// 206 /// \param Module A pointer to the module file if the module was successfully 207 /// loaded. 208 /// 209 /// \param ErrorStr Will be set to a non-empty string if any errors occurred 210 /// while trying to load the module. 211 /// 212 /// \return A pointer to the module that corresponds to this file name, 213 /// and a value indicating whether the module was loaded. 214 AddModuleResult addModule(StringRef FileName, ModuleKind Type, 215 SourceLocation ImportLoc, 216 ModuleFile *ImportedBy, unsigned Generation, 217 off_t ExpectedSize, time_t ExpectedModTime, 218 ASTFileSignature ExpectedSignature, 219 ASTFileSignatureReader ReadSignature, 220 ModuleFile *&Module, 221 std::string &ErrorStr); 222 223 /// \brief Remove the given set of modules. 224 void removeModules(ModuleIterator first, ModuleIterator last, 225 llvm::SmallPtrSetImpl<ModuleFile *> &LoadedSuccessfully, 226 ModuleMap *modMap); 227 228 /// \brief Add an in-memory buffer the list of known buffers 229 void addInMemoryBuffer(StringRef FileName, 230 std::unique_ptr<llvm::MemoryBuffer> Buffer); 231 232 /// \brief Set the global module index. 233 void setGlobalIndex(GlobalModuleIndex *Index); 234 235 /// \brief Notification from the AST reader that the given module file 236 /// has been "accepted", and will not (can not) be unloaded. 237 void moduleFileAccepted(ModuleFile *MF); 238 239 /// \brief Visit each of the modules. 240 /// 241 /// This routine visits each of the modules, starting with the 242 /// "root" modules that no other loaded modules depend on, and 243 /// proceeding to the leaf modules, visiting each module only once 244 /// during the traversal. 245 /// 246 /// This traversal is intended to support various "lookup" 247 /// operations that can find data in any of the loaded modules. 248 /// 249 /// \param Visitor A visitor function that will be invoked with each 250 /// module. The return value must be convertible to bool; when false, the 251 /// visitation continues to modules that the current module depends on. When 252 /// true, the visitation skips any modules that the current module depends on. 253 /// 254 /// \param ModuleFilesHit If non-NULL, contains the set of module files 255 /// that we know we need to visit because the global module index told us to. 256 /// Any module that is known to both the global module index and the module 257 /// manager that is *not* in this set can be skipped. 258 void visit(llvm::function_ref<bool(ModuleFile &M)> Visitor, 259 llvm::SmallPtrSetImpl<ModuleFile *> *ModuleFilesHit = nullptr); 260 261 /// \brief Attempt to resolve the given module file name to a file entry. 262 /// 263 /// \param FileName The name of the module file. 264 /// 265 /// \param ExpectedSize The size that the module file is expected to have. 266 /// If the actual size differs, the resolver should return \c true. 267 /// 268 /// \param ExpectedModTime The modification time that the module file is 269 /// expected to have. If the actual modification time differs, the resolver 270 /// should return \c true. 271 /// 272 /// \param File Will be set to the file if there is one, or null 273 /// otherwise. 274 /// 275 /// \returns True if a file exists but does not meet the size/ 276 /// modification time criteria, false if the file is either available and 277 /// suitable, or is missing. 278 bool lookupModuleFile(StringRef FileName, 279 off_t ExpectedSize, 280 time_t ExpectedModTime, 281 const FileEntry *&File); 282 283 /// \brief View the graphviz representation of the module graph. 284 void viewGraph(); 285 }; 286 287 } } // end namespace clang::serialization 288 289 #endif 290