1 //===--- ModuleManager.cpp - Module Manager ---------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the ModuleManager class, which manages a set of loaded
11 // modules for the ASTReader.
13 //===----------------------------------------------------------------------===//
14 #include "clang/Lex/HeaderSearch.h"
15 #include "clang/Lex/ModuleMap.h"
16 #include "clang/Serialization/GlobalModuleIndex.h"
17 #include "clang/Serialization/ModuleManager.h"
18 #include "llvm/Support/MemoryBuffer.h"
19 #include "llvm/Support/Path.h"
20 #include "llvm/Support/raw_ostream.h"
21 #include <system_error>
24 #include "llvm/Support/GraphWriter.h"
27 using namespace clang;
28 using namespace serialization;
30 ModuleFile *ModuleManager::lookup(StringRef Name) {
31 const FileEntry *Entry = FileMgr.getFile(Name, /*openFile=*/false,
32 /*cacheFailure=*/false);
39 ModuleFile *ModuleManager::lookup(const FileEntry *File) {
40 llvm::DenseMap<const FileEntry *, ModuleFile *>::iterator Known
42 if (Known == Modules.end())
48 std::unique_ptr<llvm::MemoryBuffer>
49 ModuleManager::lookupBuffer(StringRef Name) {
50 const FileEntry *Entry = FileMgr.getFile(Name, /*openFile=*/false,
51 /*cacheFailure=*/false);
52 return std::move(InMemoryBuffers[Entry]);
55 ModuleManager::AddModuleResult
56 ModuleManager::addModule(StringRef FileName, ModuleKind Type,
57 SourceLocation ImportLoc, ModuleFile *ImportedBy,
59 off_t ExpectedSize, time_t ExpectedModTime,
60 ASTFileSignature ExpectedSignature,
61 ASTFileSignatureReader ReadSignature,
63 std::string &ErrorStr) {
66 // Look for the file entry. This only fails if the expected size or
67 // modification time differ.
68 const FileEntry *Entry;
69 if (Type == MK_ExplicitModule) {
70 // If we're not expecting to pull this file out of the module cache, it
71 // might have a different mtime due to being moved across filesystems in
72 // a distributed build. The size must still match, though. (As must the
73 // contents, but we can't check that.)
76 if (lookupModuleFile(FileName, ExpectedSize, ExpectedModTime, Entry)) {
77 ErrorStr = "module file out of date";
81 if (!Entry && FileName != "-") {
82 ErrorStr = "module file not found";
86 // Check whether we already loaded this module, before
87 ModuleFile *&ModuleEntry = Modules[Entry];
88 bool NewModule = false;
90 // Allocate a new module.
91 ModuleFile *New = new ModuleFile(Type, Generation);
92 New->Index = Chain.size();
93 New->FileName = FileName.str();
95 New->ImportLoc = ImportLoc;
102 New->InputFilesValidationTimestamp = 0;
103 if (New->Kind == MK_ImplicitModule) {
104 std::string TimestampFilename = New->getTimestampFilename();
106 // A cached stat value would be fine as well.
107 if (!FileMgr.getNoncachedStatValue(TimestampFilename, Status))
108 New->InputFilesValidationTimestamp =
109 Status.getLastModificationTime().toEpochTime();
112 // Load the contents of the module
113 if (std::unique_ptr<llvm::MemoryBuffer> Buffer = lookupBuffer(FileName)) {
114 // The buffer was already provided for us.
115 New->Buffer = std::move(Buffer);
117 // Open the AST file.
118 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buf(
119 (std::error_code()));
120 if (FileName == "-") {
121 Buf = llvm::MemoryBuffer::getSTDIN();
123 // Leave the FileEntry open so if it gets read again by another
124 // ModuleManager it must be the same underlying file.
125 // FIXME: Because FileManager::getFile() doesn't guarantee that it will
126 // give us an open file, this may not be 100% reliable.
127 Buf = FileMgr.getBufferForFile(New->File,
128 /*IsVolatile=*/false,
129 /*ShouldClose=*/false);
133 ErrorStr = Buf.getError().message();
137 New->Buffer = std::move(*Buf);
140 // Initialize the stream
141 New->StreamFile.init((const unsigned char *)New->Buffer->getBufferStart(),
142 (const unsigned char *)New->Buffer->getBufferEnd());
145 if (ExpectedSignature) {
147 ModuleEntry->Signature = ReadSignature(ModuleEntry->StreamFile);
149 assert(ModuleEntry->Signature == ReadSignature(ModuleEntry->StreamFile));
151 if (ModuleEntry->Signature != ExpectedSignature) {
152 ErrorStr = ModuleEntry->Signature ? "signature mismatch"
153 : "could not read module signature";
156 // Remove the module file immediately, since removeModules might try to
157 // invalidate the file cache for Entry, and that is not safe if this
158 // module is *itself* up to date, but has an out-of-date importer.
159 Modules.erase(Entry);
160 assert(Chain.back() == ModuleEntry);
162 if (Roots.back() == ModuleEntry)
173 ModuleEntry->ImportedBy.insert(ImportedBy);
174 ImportedBy->Imports.insert(ModuleEntry);
176 if (!ModuleEntry->DirectlyImported)
177 ModuleEntry->ImportLoc = ImportLoc;
179 ModuleEntry->DirectlyImported = true;
182 Module = ModuleEntry;
183 return NewModule? NewlyLoaded : AlreadyLoaded;
186 void ModuleManager::removeModules(
187 ModuleIterator first, ModuleIterator last,
188 llvm::SmallPtrSetImpl<ModuleFile *> &LoadedSuccessfully,
193 // Collect the set of module file pointers that we'll be removing.
194 llvm::SmallPtrSet<ModuleFile *, 4> victimSet(first, last);
196 auto IsVictim = [&](ModuleFile *MF) {
197 return victimSet.count(MF);
199 // Remove any references to the now-destroyed modules.
200 for (unsigned i = 0, n = Chain.size(); i != n; ++i) {
201 Chain[i]->ImportedBy.remove_if(IsVictim);
203 Roots.erase(std::remove_if(Roots.begin(), Roots.end(), IsVictim),
206 // Delete the modules and erase them from the various structures.
207 for (ModuleIterator victim = first; victim != last; ++victim) {
208 Modules.erase((*victim)->File);
211 StringRef ModuleName = (*victim)->ModuleName;
212 if (Module *mod = modMap->findModule(ModuleName)) {
213 mod->setASTFile(nullptr);
217 // Files that didn't make it through ReadASTCore successfully will be
218 // rebuilt (or there was an error). Invalidate them so that we can load the
219 // new files that will be renamed over the old ones.
220 if (LoadedSuccessfully.count(*victim) == 0)
221 FileMgr.invalidateCache((*victim)->File);
226 // Remove the modules from the chain.
227 Chain.erase(first, last);
231 ModuleManager::addInMemoryBuffer(StringRef FileName,
232 std::unique_ptr<llvm::MemoryBuffer> Buffer) {
234 const FileEntry *Entry =
235 FileMgr.getVirtualFile(FileName, Buffer->getBufferSize(), 0);
236 InMemoryBuffers[Entry] = std::move(Buffer);
239 bool ModuleManager::addKnownModuleFile(StringRef FileName) {
240 const FileEntry *File;
241 if (lookupModuleFile(FileName, 0, 0, File))
243 if (!Modules.count(File))
244 AdditionalKnownModuleFiles.insert(File);
248 ModuleManager::VisitState *ModuleManager::allocateVisitState() {
249 // Fast path: if we have a cached state, use it.
250 if (FirstVisitState) {
251 VisitState *Result = FirstVisitState;
252 FirstVisitState = FirstVisitState->NextState;
253 Result->NextState = nullptr;
257 // Allocate and return a new state.
258 return new VisitState(size());
261 void ModuleManager::returnVisitState(VisitState *State) {
262 assert(State->NextState == nullptr && "Visited state is in list?");
263 State->NextState = FirstVisitState;
264 FirstVisitState = State;
267 void ModuleManager::setGlobalIndex(GlobalModuleIndex *Index) {
270 ModulesInCommonWithGlobalIndex.clear();
274 // Notify the global module index about all of the modules we've already
276 for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
277 if (!GlobalIndex->loadedModuleFile(Chain[I])) {
278 ModulesInCommonWithGlobalIndex.push_back(Chain[I]);
283 void ModuleManager::moduleFileAccepted(ModuleFile *MF) {
284 AdditionalKnownModuleFiles.remove(MF->File);
286 if (!GlobalIndex || GlobalIndex->loadedModuleFile(MF))
289 ModulesInCommonWithGlobalIndex.push_back(MF);
292 ModuleManager::ModuleManager(FileManager &FileMgr)
293 : FileMgr(FileMgr), GlobalIndex(), FirstVisitState(nullptr) {}
295 ModuleManager::~ModuleManager() {
296 for (unsigned i = 0, e = Chain.size(); i != e; ++i)
297 delete Chain[e - i - 1];
298 delete FirstVisitState;
302 ModuleManager::visit(bool (*Visitor)(ModuleFile &M, void *UserData),
304 llvm::SmallPtrSetImpl<ModuleFile *> *ModuleFilesHit) {
305 // If the visitation order vector is the wrong size, recompute the order.
306 if (VisitOrder.size() != Chain.size()) {
309 VisitOrder.reserve(N);
311 // Record the number of incoming edges for each module. When we
312 // encounter a module with no incoming edges, push it into the queue
313 // to seed the queue.
314 SmallVector<ModuleFile *, 4> Queue;
316 llvm::SmallVector<unsigned, 4> UnusedIncomingEdges;
317 UnusedIncomingEdges.reserve(size());
318 for (ModuleIterator M = begin(), MEnd = end(); M != MEnd; ++M) {
319 if (unsigned Size = (*M)->ImportedBy.size())
320 UnusedIncomingEdges.push_back(Size);
322 UnusedIncomingEdges.push_back(0);
327 // Traverse the graph, making sure to visit a module before visiting any
328 // of its dependencies.
329 unsigned QueueStart = 0;
330 while (QueueStart < Queue.size()) {
331 ModuleFile *CurrentModule = Queue[QueueStart++];
332 VisitOrder.push_back(CurrentModule);
334 // For any module that this module depends on, push it on the
335 // stack (if it hasn't already been marked as visited).
336 for (llvm::SetVector<ModuleFile *>::iterator
337 M = CurrentModule->Imports.begin(),
338 MEnd = CurrentModule->Imports.end();
340 // Remove our current module as an impediment to visiting the
341 // module we depend on. If we were the last unvisited module
342 // that depends on this particular module, push it into the
343 // queue to be visited.
344 unsigned &NumUnusedEdges = UnusedIncomingEdges[(*M)->Index];
345 if (NumUnusedEdges && (--NumUnusedEdges == 0))
350 assert(VisitOrder.size() == N && "Visitation order is wrong?");
352 delete FirstVisitState;
353 FirstVisitState = nullptr;
356 VisitState *State = allocateVisitState();
357 unsigned VisitNumber = State->NextVisitNumber++;
359 // If the caller has provided us with a hit-set that came from the global
360 // module index, mark every module file in common with the global module
361 // index that is *not* in that set as 'visited'.
362 if (ModuleFilesHit && !ModulesInCommonWithGlobalIndex.empty()) {
363 for (unsigned I = 0, N = ModulesInCommonWithGlobalIndex.size(); I != N; ++I)
365 ModuleFile *M = ModulesInCommonWithGlobalIndex[I];
366 if (!ModuleFilesHit->count(M))
367 State->VisitNumber[M->Index] = VisitNumber;
371 for (unsigned I = 0, N = VisitOrder.size(); I != N; ++I) {
372 ModuleFile *CurrentModule = VisitOrder[I];
373 // Should we skip this module file?
374 if (State->VisitNumber[CurrentModule->Index] == VisitNumber)
378 assert(State->VisitNumber[CurrentModule->Index] == VisitNumber - 1);
379 State->VisitNumber[CurrentModule->Index] = VisitNumber;
380 if (!Visitor(*CurrentModule, UserData))
383 // The visitor has requested that cut off visitation of any
384 // module that the current module depends on. To indicate this
385 // behavior, we mark all of the reachable modules as having been visited.
386 ModuleFile *NextModule = CurrentModule;
388 // For any module that this module depends on, push it on the
389 // stack (if it hasn't already been marked as visited).
390 for (llvm::SetVector<ModuleFile *>::iterator
391 M = NextModule->Imports.begin(),
392 MEnd = NextModule->Imports.end();
394 if (State->VisitNumber[(*M)->Index] != VisitNumber) {
395 State->Stack.push_back(*M);
396 State->VisitNumber[(*M)->Index] = VisitNumber;
400 if (State->Stack.empty())
403 // Pop the next module off the stack.
404 NextModule = State->Stack.pop_back_val();
408 returnVisitState(State);
411 static void markVisitedDepthFirst(ModuleFile &M,
412 SmallVectorImpl<bool> &Visited) {
413 for (llvm::SetVector<ModuleFile *>::iterator IM = M.Imports.begin(),
414 IMEnd = M.Imports.end();
416 if (Visited[(*IM)->Index])
418 Visited[(*IM)->Index] = true;
419 if (!M.DirectlyImported)
420 markVisitedDepthFirst(**IM, Visited);
424 /// \brief Perform a depth-first visit of the current module.
425 static bool visitDepthFirst(
427 ModuleManager::DFSPreorderControl (*PreorderVisitor)(ModuleFile &M,
429 bool (*PostorderVisitor)(ModuleFile &M, void *UserData), void *UserData,
430 SmallVectorImpl<bool> &Visited) {
431 if (PreorderVisitor) {
432 switch (PreorderVisitor(M, UserData)) {
433 case ModuleManager::Abort:
435 case ModuleManager::SkipImports:
436 markVisitedDepthFirst(M, Visited);
438 case ModuleManager::Continue:
444 for (llvm::SetVector<ModuleFile *>::iterator IM = M.Imports.begin(),
445 IMEnd = M.Imports.end();
447 if (Visited[(*IM)->Index])
449 Visited[(*IM)->Index] = true;
451 if (visitDepthFirst(**IM, PreorderVisitor, PostorderVisitor, UserData, Visited))
455 if (PostorderVisitor)
456 return PostorderVisitor(M, UserData);
461 void ModuleManager::visitDepthFirst(
462 ModuleManager::DFSPreorderControl (*PreorderVisitor)(ModuleFile &M,
464 bool (*PostorderVisitor)(ModuleFile &M, void *UserData), void *UserData) {
465 SmallVector<bool, 16> Visited(size(), false);
466 for (unsigned I = 0, N = Roots.size(); I != N; ++I) {
467 if (Visited[Roots[I]->Index])
469 Visited[Roots[I]->Index] = true;
471 if (::visitDepthFirst(*Roots[I], PreorderVisitor, PostorderVisitor, UserData, Visited))
476 bool ModuleManager::lookupModuleFile(StringRef FileName,
478 time_t ExpectedModTime,
479 const FileEntry *&File) {
480 // Open the file immediately to ensure there is no race between stat'ing and
482 File = FileMgr.getFile(FileName, /*openFile=*/true, /*cacheFailure=*/false);
484 if (!File && FileName != "-") {
488 if ((ExpectedSize && ExpectedSize != File->getSize()) ||
489 (ExpectedModTime && ExpectedModTime != File->getModificationTime()))
490 // Do not destroy File, as it may be referenced. If we need to rebuild it,
491 // it will be destroyed by removeModules.
500 struct GraphTraits<ModuleManager> {
501 typedef ModuleFile NodeType;
502 typedef llvm::SetVector<ModuleFile *>::const_iterator ChildIteratorType;
503 typedef ModuleManager::ModuleConstIterator nodes_iterator;
505 static ChildIteratorType child_begin(NodeType *Node) {
506 return Node->Imports.begin();
509 static ChildIteratorType child_end(NodeType *Node) {
510 return Node->Imports.end();
513 static nodes_iterator nodes_begin(const ModuleManager &Manager) {
514 return Manager.begin();
517 static nodes_iterator nodes_end(const ModuleManager &Manager) {
518 return Manager.end();
523 struct DOTGraphTraits<ModuleManager> : public DefaultDOTGraphTraits {
524 explicit DOTGraphTraits(bool IsSimple = false)
525 : DefaultDOTGraphTraits(IsSimple) { }
527 static bool renderGraphFromBottomUp() {
531 std::string getNodeLabel(ModuleFile *M, const ModuleManager&) {
532 return M->ModuleName;
537 void ModuleManager::viewGraph() {
538 llvm::ViewGraph(*this, "Modules");