ModuleManager.h revision 677e15ffee2ecc9c1c8f46fd77cab4b5afb59640 
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_MODULE_MANAGER_H
16#define LLVM_CLANG_SERIALIZATION_MODULE_MANAGER_H
17
18#include "clang/Basic/FileManager.h"
19#include "clang/Serialization/GlobalModuleIndex.h"
20#include "clang/Serialization/Module.h"
21#include "llvm/ADT/DenseMap.h"
22
23namespace clang {
24
25class ModuleMap;
26
27namespace serialization {
28
29/// \brief Manages the set of modules loaded by an AST reader.
30class ModuleManager : public ModuleFileNameResolver {
31  /// \brief The chain of AST files. The first entry is the one named by the
32  /// user, the last one is the one that doesn't depend on anything further.
33  SmallVector<ModuleFile *, 2> Chain;
34
35  /// \brief All loaded modules, indexed by name.
36  llvm::DenseMap<const FileEntry *, ModuleFile *> Modules;
37
38  /// \brief FileManager that handles translating between filenames and
39  /// FileEntry *.
40  FileManager &FileMgr;
41
42  /// \brief A lookup of in-memory (virtual file) buffers
43  llvm::DenseMap<const FileEntry *, llvm::MemoryBuffer *> InMemoryBuffers;
44
45  /// \brief The visitation order.
46  SmallVector<ModuleFile *, 4> VisitOrder;
47
48  /// \brief The list of module files that both we and the global module index
49  /// know about.
50  ///
51  /// Either the global index or the module manager may have modules that the
52  /// other does not know about, because the global index can be out-of-date
53  /// (in which case the module manager could have modules it does not) and
54  /// this particular translation unit might not have loaded all of the modules
55  /// known to the global index.
56  SmallVector<ModuleFile *, 4> ModulesInCommonWithGlobalIndex;
57
58  /// \brief The global module index, if one is attached.
59  ///
60  /// The global module index will actually be owned by the ASTReader; this is
61  /// just an non-owning pointer.
62  GlobalModuleIndex *GlobalIndex;
63
64  /// \brief Update the set of modules files we know about known to the global index.
65  void updateModulesInCommonWithGlobalIndex();
66
67  /// \brief State used by the "visit" operation to avoid malloc traffic in
68  /// calls to visit().
69  struct VisitState {
70    explicit VisitState(unsigned N)
71      : VisitNumber(N, 0), NextVisitNumber(1), NextState(0)
72    {
73      Stack.reserve(N);
74    }
75
76    ~VisitState() {
77      delete NextState;
78    }
79
80    /// \brief The stack used when marking the imports of a particular module
81    /// as not-to-be-visited.
82    SmallVector<ModuleFile *, 4> Stack;
83
84    /// \brief The visit number of each module file, which indicates when
85    /// this module file was last visited.
86    SmallVector<unsigned, 4> VisitNumber;
87
88    /// \brief The next visit number to use to mark visited module files.
89    unsigned NextVisitNumber;
90
91    /// \brief The next visit state.
92    VisitState *NextState;
93  };
94
95  /// \brief The first visit() state in the chain.
96  VisitState *FirstVisitState;
97
98  VisitState *allocateVisitState();
99  void returnVisitState(VisitState *State);
100
101public:
102  typedef SmallVector<ModuleFile*, 2>::iterator ModuleIterator;
103  typedef SmallVector<ModuleFile*, 2>::const_iterator ModuleConstIterator;
104  typedef SmallVector<ModuleFile*, 2>::reverse_iterator ModuleReverseIterator;
105  typedef std::pair<uint32_t, StringRef> ModuleOffset;
106
107  explicit ModuleManager(FileManager &FileMgr);
108  ~ModuleManager();
109
110  /// \brief Forward iterator to traverse all loaded modules.  This is reverse
111  /// source-order.
112  ModuleIterator begin() { return Chain.begin(); }
113  /// \brief Forward iterator end-point to traverse all loaded modules
114  ModuleIterator end() { return Chain.end(); }
115
116  /// \brief Const forward iterator to traverse all loaded modules.  This is
117  /// in reverse source-order.
118  ModuleConstIterator begin() const { return Chain.begin(); }
119  /// \brief Const forward iterator end-point to traverse all loaded modules
120  ModuleConstIterator end() const { return Chain.end(); }
121
122  /// \brief Reverse iterator to traverse all loaded modules.  This is in
123  /// source order.
124  ModuleReverseIterator rbegin() { return Chain.rbegin(); }
125  /// \brief Reverse iterator end-point to traverse all loaded modules.
126  ModuleReverseIterator rend() { return Chain.rend(); }
127
128  /// \brief Returns the primary module associated with the manager, that is,
129  /// the first module loaded
130  ModuleFile &getPrimaryModule() { return *Chain[0]; }
131
132  /// \brief Returns the primary module associated with the manager, that is,
133  /// the first module loaded.
134  ModuleFile &getPrimaryModule() const { return *Chain[0]; }
135
136  /// \brief Returns the module associated with the given index
137  ModuleFile &operator[](unsigned Index) const { return *Chain[Index]; }
138
139  /// \brief Returns the module associated with the given name
140  ModuleFile *lookup(StringRef Name);
141
142  /// \brief Returns the in-memory (virtual file) buffer with the given name
143  llvm::MemoryBuffer *lookupBuffer(StringRef Name);
144
145  /// \brief Number of modules loaded
146  unsigned size() const { return Chain.size(); }
147
148  /// \brief The result of attempting to add a new module.
149  enum AddModuleResult {
150    /// \brief The module file had already been loaded.
151    AlreadyLoaded,
152    /// \brief The module file was just loaded in response to this call.
153    NewlyLoaded,
154    /// \brief The module file is missing.
155    Missing,
156    /// \brief The module file is out-of-date.
157    OutOfDate
158  };
159
160  /// \brief Attempts to create a new module and add it to the list of known
161  /// modules.
162  ///
163  /// \param FileName The file name of the module to be loaded.
164  ///
165  /// \param Type The kind of module being loaded.
166  ///
167  /// \param ImportLoc The location at which the module is imported.
168  ///
169  /// \param ImportedBy The module that is importing this module, or NULL if
170  /// this module is imported directly by the user.
171  ///
172  /// \param Generation The generation in which this module was loaded.
173  ///
174  /// \param ExpectedSize The expected size of the module file, used for
175  /// validation. This will be zero if unknown.
176  ///
177  /// \param ExpectedModTime The expected modification time of the module
178  /// file, used for validation. This will be zero if unknown.
179  ///
180  /// \param Module A pointer to the module file if the module was successfully
181  /// loaded.
182  ///
183  /// \param ErrorStr Will be set to a non-empty string if any errors occurred
184  /// while trying to load the module.
185  ///
186  /// \return A pointer to the module that corresponds to this file name,
187  /// and a value indicating whether the module was loaded.
188  AddModuleResult addModule(StringRef FileName, ModuleKind Type,
189                            SourceLocation ImportLoc,
190                            ModuleFile *ImportedBy, unsigned Generation,
191                            off_t ExpectedSize, time_t ExpectedModTime,
192                            ModuleFile *&Module,
193                            std::string &ErrorStr);
194
195  /// \brief Remove the given set of modules.
196  void removeModules(ModuleIterator first, ModuleIterator last,
197                     ModuleMap *modMap);
198
199  /// \brief Add an in-memory buffer the list of known buffers
200  void addInMemoryBuffer(StringRef FileName, llvm::MemoryBuffer *Buffer);
201
202  /// \brief Set the global module index.
203  void setGlobalIndex(GlobalModuleIndex *Index);
204
205  /// \brief Visit each of the modules.
206  ///
207  /// This routine visits each of the modules, starting with the
208  /// "root" modules that no other loaded modules depend on, and
209  /// proceeding to the leaf modules, visiting each module only once
210  /// during the traversal.
211  ///
212  /// This traversal is intended to support various "lookup"
213  /// operations that can find data in any of the loaded modules.
214  ///
215  /// \param Visitor A visitor function that will be invoked with each
216  /// module and the given user data pointer. The return value must be
217  /// convertible to bool; when false, the visitation continues to
218  /// modules that the current module depends on. When true, the
219  /// visitation skips any modules that the current module depends on.
220  ///
221  /// \param UserData User data associated with the visitor object, which
222  /// will be passed along to the visitor.
223  ///
224  /// \param ModuleFilesHit If non-NULL, contains the set of module files
225  /// that we know we need to visit because the global module index told us to.
226  /// Any module that is known to both the global module index and the module
227  /// manager that is *not* in this set can be skipped.
228  void visit(bool (*Visitor)(ModuleFile &M, void *UserData), void *UserData,
229             llvm::SmallPtrSet<ModuleFile *, 4> *ModuleFilesHit = 0);
230
231  /// \brief Visit each of the modules with a depth-first traversal.
232  ///
233  /// This routine visits each of the modules known to the module
234  /// manager using a depth-first search, starting with the first
235  /// loaded module. The traversal invokes the callback both before
236  /// traversing the children (preorder traversal) and after
237  /// traversing the children (postorder traversal).
238  ///
239  /// \param Visitor A visitor function that will be invoked with each
240  /// module and given a \c Preorder flag that indicates whether we're
241  /// visiting the module before or after visiting its children.  The
242  /// visitor may return true at any time to abort the depth-first
243  /// visitation.
244  ///
245  /// \param UserData User data ssociated with the visitor object,
246  /// which will be passed along to the user.
247  void visitDepthFirst(bool (*Visitor)(ModuleFile &M, bool Preorder,
248                                       void *UserData),
249                       void *UserData);
250
251  /// \brief Attempt to resolve the given module file name to a file entry.
252  ///
253  /// \param FileName The name of the module file.
254  ///
255  /// \param ExpectedSize The size that the module file is expected to have.
256  /// If the actual size differs, the resolver should return \c true.
257  ///
258  /// \param ExpectedModTime The modification time that the module file is
259  /// expected to have. If the actual modification time differs, the resolver
260  /// should return \c true.
261  ///
262  /// \param File Will be set to the file if there is one, or null
263  /// otherwise.
264  ///
265  /// \returns True if a file exists but does not meet the size/
266  /// modification time criteria, false if the file is either available and
267  /// suitable, or is missing.
268  bool lookupModuleFile(StringRef FileName,
269                        off_t ExpectedSize,
270                        time_t ExpectedModTime,
271                        const FileEntry *&File);
272
273  virtual bool resolveModuleFileName(StringRef FileName,
274                                     off_t ExpectedSize,
275                                     time_t ExpectedModTime,
276                                     ModuleFile *&File);
277
278  /// \brief View the graphviz representation of the module graph.
279  void viewGraph();
280};
281
282} } // end namespace clang::serialization
283
284#endif
285