1 files changed, 253 insertions, 0 deletions
diff --git a/lib/Serialization/ModuleManager.cpp b/lib/Serialization/ModuleManager.cpp
new file mode 100644
index 0000000000000..c4b1f7199bedd
--- /dev/null
+++ b/lib/Serialization/ModuleManager.cpp
@@ -0,0 +1,253 @@
+//===--- ModuleManager.cpp - Module Manager ---------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the ModuleManager class, which manages a set of loaded
+//  modules for the ASTReader.
+//
+//===----------------------------------------------------------------------===//
+#include "clang/Serialization/ModuleManager.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/system_error.h"
+
+#ifndef NDEBUG
+#include "llvm/Support/GraphWriter.h"
+#endif
+
+using namespace clang;
+using namespace serialization;
+
+Module *ModuleManager::lookup(StringRef Name) {
+  const FileEntry *Entry = FileMgr.getFile(Name);
+  return Modules[Entry];
+}
+
+llvm::MemoryBuffer *ModuleManager::lookupBuffer(StringRef Name) {
+  const FileEntry *Entry = FileMgr.getFile(Name);
+  return InMemoryBuffers[Entry];
+}
+
+std::pair<Module *, bool>
+ModuleManager::addModule(StringRef FileName, ModuleKind Type, 
+                         Module *ImportedBy, std::string &ErrorStr) {
+  const FileEntry *Entry = FileMgr.getFile(FileName);
+  if (!Entry && FileName != "-") {
+    ErrorStr = "file not found";
+    return std::make_pair(static_cast<Module*>(0), false);
+  }
+  
+  // Check whether we already loaded this module, before 
+  Module *&ModuleEntry = Modules[Entry];
+  bool NewModule = false;
+  if (!ModuleEntry) {
+    // Allocate a new module.
+    Module *New = new Module(Type);
+    New->FileName = FileName.str();
+    Chain.push_back(New);
+    NewModule = true;
+    ModuleEntry = New;
+    
+    // Load the contents of the module
+    if (llvm::MemoryBuffer *Buffer = lookupBuffer(FileName)) {
+      // The buffer was already provided for us.
+      assert(Buffer && "Passed null buffer");
+      New->Buffer.reset(Buffer);
+    } else {
+      // Open the AST file.
+      llvm::error_code ec;
+      if (FileName == "-") {
+        ec = llvm::MemoryBuffer::getSTDIN(New->Buffer);
+        if (ec)
+          ErrorStr = ec.message();
+      } else
+        New->Buffer.reset(FileMgr.getBufferForFile(FileName, &ErrorStr));
+      
+      if (!New->Buffer)
+        return std::make_pair(static_cast<Module*>(0), false);
+    }
+    
+    // Initialize the stream
+    New->StreamFile.init((const unsigned char *)New->Buffer->getBufferStart(),
+                         (const unsigned char *)New->Buffer->getBufferEnd());     }
+  
+  if (ImportedBy) {
+    ModuleEntry->ImportedBy.insert(ImportedBy);
+    ImportedBy->Imports.insert(ModuleEntry);
+  } else {
+    ModuleEntry->DirectlyImported = true;
+  }
+  
+  return std::make_pair(ModuleEntry, NewModule);
+}
+
+void ModuleManager::addInMemoryBuffer(StringRef FileName, 
+                                      llvm::MemoryBuffer *Buffer) {
+  
+  const FileEntry *Entry = FileMgr.getVirtualFile(FileName, 
+                                                  Buffer->getBufferSize(), 0);
+  InMemoryBuffers[Entry] = Buffer;
+}
+
+ModuleManager::ModuleManager(const FileSystemOptions &FSO) : FileMgr(FSO) { }
+
+ModuleManager::~ModuleManager() {
+  for (unsigned i = 0, e = Chain.size(); i != e; ++i)
+    delete Chain[e - i - 1];
+}
+
+void ModuleManager::visit(bool (*Visitor)(Module &M, void *UserData), 
+                          void *UserData) {
+  unsigned N = size();
+  
+  // Record the number of incoming edges for each module. When we
+  // encounter a module with no incoming edges, push it into the queue
+  // to seed the queue.
+  SmallVector<Module *, 4> Queue;
+  Queue.reserve(N);
+  llvm::DenseMap<Module *, unsigned> UnusedIncomingEdges; 
+  for (ModuleIterator M = begin(), MEnd = end(); M != MEnd; ++M) {
+    if (unsigned Size = (*M)->ImportedBy.size())
+      UnusedIncomingEdges[*M] = Size;
+    else
+      Queue.push_back(*M);
+  }
+  
+  llvm::SmallPtrSet<Module *, 4> Skipped;
+  unsigned QueueStart = 0;
+  while (QueueStart < Queue.size()) {
+    Module *CurrentModule = Queue[QueueStart++];
+    
+    // Check whether this module should be skipped.
+    if (Skipped.count(CurrentModule))
+      continue;
+    
+    if (Visitor(*CurrentModule, UserData)) {
+      // The visitor has requested that cut off visitation of any
+      // module that the current module depends on. To indicate this
+      // behavior, we mark all of the reachable modules as having N
+      // incoming edges (which is impossible otherwise).
+      SmallVector<Module *, 4> Stack;
+      Stack.push_back(CurrentModule);
+      Skipped.insert(CurrentModule);
+      while (!Stack.empty()) {
+        Module *NextModule = Stack.back();
+        Stack.pop_back();
+        
+        // For any module that this module depends on, push it on the
+        // stack (if it hasn't already been marked as visited).
+        for (llvm::SetVector<Module *>::iterator 
+             M = NextModule->Imports.begin(),
+             MEnd = NextModule->Imports.end();
+             M != MEnd; ++M) {
+          if (Skipped.insert(*M))
+            Stack.push_back(*M);
+        }
+      }
+      continue;
+    }
+    
+    // For any module that this module depends on, push it on the
+    // stack (if it hasn't already been marked as visited).
+    for (llvm::SetVector<Module *>::iterator M = CurrentModule->Imports.begin(),
+         MEnd = CurrentModule->Imports.end();
+         M != MEnd; ++M) {
+      
+      // Remove our current module as an impediment to visiting the
+      // module we depend on. If we were the last unvisited module
+      // that depends on this particular module, push it into the
+      // queue to be visited.
+      unsigned &NumUnusedEdges = UnusedIncomingEdges[*M];
+      if (NumUnusedEdges && (--NumUnusedEdges == 0))
+        Queue.push_back(*M);
+    }
+  }
+}
+
+/// \brief Perform a depth-first visit of the current module.
+static bool visitDepthFirst(Module &M, 
+                            bool (*Visitor)(Module &M, bool Preorder, 
+                                            void *UserData), 
+                            void *UserData,
+                            llvm::SmallPtrSet<Module *, 4> &Visited) {
+  // Preorder visitation
+  if (Visitor(M, /*Preorder=*/true, UserData))
+    return true;
+  
+  // Visit children
+  for (llvm::SetVector<Module *>::iterator IM = M.Imports.begin(),
+       IMEnd = M.Imports.end();
+       IM != IMEnd; ++IM) {
+    if (!Visited.insert(*IM))
+      continue;
+    
+    if (visitDepthFirst(**IM, Visitor, UserData, Visited))
+      return true;
+  }  
+  
+  // Postorder visitation
+  return Visitor(M, /*Preorder=*/false, UserData);
+}
+
+void ModuleManager::visitDepthFirst(bool (*Visitor)(Module &M, bool Preorder, 
+                                                    void *UserData), 
+                                    void *UserData) {
+  llvm::SmallPtrSet<Module *, 4> Visited;
+  for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
+    if (!Visited.insert(Chain[I]))
+      continue;
+    
+    if (::visitDepthFirst(*Chain[I], Visitor, UserData, Visited))
+      return;
+  }
+}
+
+#ifndef NDEBUG
+namespace llvm {
+  template<>
+  struct GraphTraits<ModuleManager> {
+    typedef Module NodeType;
+    typedef llvm::SetVector<Module *>::const_iterator ChildIteratorType;
+    typedef ModuleManager::ModuleConstIterator nodes_iterator;
+    
+    static ChildIteratorType child_begin(NodeType *Node) {
+      return Node->Imports.begin();
+    }
+
+    static ChildIteratorType child_end(NodeType *Node) {
+      return Node->Imports.end();
+    }
+    
+    static nodes_iterator nodes_begin(const ModuleManager &Manager) {
+      return Manager.begin();
+    }
+    
+    static nodes_iterator nodes_end(const ModuleManager &Manager) {
+      return Manager.end();
+    }
+  };
+  
+  template<>
+  struct DOTGraphTraits<ModuleManager> : public DefaultDOTGraphTraits {
+    explicit DOTGraphTraits(bool IsSimple = false)
+      : DefaultDOTGraphTraits(IsSimple) { }
+    
+    static bool renderGraphFromBottomUp() {
+      return true;
+    }
+
+    std::string getNodeLabel(Module *M, const ModuleManager&) {
+      return llvm::sys::path::stem(M->FileName);
+    }
+  };
+}
+
+void ModuleManager::viewGraph() {
+  llvm::ViewGraph(*this, "Modules");
+}
+#endif