Following up the earlier refactoring/cleanup work by fixing up how we manage the virtual files the ASTReader has to handle. Specifically, this occurs when the reader is reading AST files that were created in memory and not written to disk. For example, when a user creates a chained PCH using command line flags. These virtual files are stored in MemoryBuffers in ChainIncludeSource.cpp, and then read back in by the ASTReader. This patch moves the management of these buffers into the ModuleManager, so that it becomes the authority on where these buffers are located.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136697 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 42 insertions, 20 deletions

diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index e167985e30..5d663105cc 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -436,6 +436,9 @@ class ModuleManager {
   /// \brief FileManager that handles translating between filenames and
   /// FileEntry *.
   FileManager FileMgr;
+  
+  /// \brief A lookup of in-memory (virtual file) buffers
+  llvm::DenseMap<const FileEntry *, llvm::MemoryBuffer *> InMemoryBuffers;
 
 public:
   typedef SmallVector<Module*, 2>::iterator ModuleIterator;
@@ -481,12 +484,18 @@ public:
 
   /// \brief Returns the module associated with the given name
   Module *lookup(StringRef Name);
+  
+  /// \brief Returns the in-memory (virtual file) buffer with the given name
+  llvm::MemoryBuffer *lookupBuffer(StringRef Name);
 
   /// \brief Number of modules loaded
   unsigned size() const { return Chain.size(); }
 
   /// \brief Creates a new module and adds it to the list of known modules
   Module &addModule(StringRef FileName, ModuleKind Type);
+  
+  /// \brief Add an in-memory buffer the list of known buffers
+  void addInMemoryBuffer(StringRef FileName, llvm::MemoryBuffer *Buffer);
 
   /// \brief Exports the list of loaded modules with their corresponding names
   void exportLookup(SmallVector<ModuleOffset, 16> &Target);
@@ -559,10 +568,6 @@ private:
   /// \brief The AST consumer.
   ASTConsumer *Consumer;
 
-  /// \brief AST buffers for chained PCHs created and stored in memory.
-  /// First (not depending on another) PCH in chain is in front.
-  std::vector<llvm::MemoryBuffer *> ASTBuffers;
-
   /// \brief The module manager which manages modules and their dependencies
   ModuleManager ModuleMgr;
 
@@ -1138,11 +1143,9 @@ public:
   /// \brief Sets and initializes the given Context.
   void InitializeContext(ASTContext &Context);
 
-  /// \brief Set AST buffers for chained PCHs created and stored in memory.
-  /// First (not depending on another) PCH in chain is first in array.
-  void setASTMemoryBuffers(llvm::MemoryBuffer **bufs, unsigned numBufs) {
-    ASTBuffers.clear();
-    ASTBuffers.insert(ASTBuffers.begin(), bufs, bufs + numBufs);
+  /// \brief Add in-memory (virtual file) buffer.
+  void addInMemoryBuffer(StringRef &FileName, llvm::MemoryBuffer *Buffer) {
+    ModuleMgr.addInMemoryBuffer(FileName, Buffer);
   }
 
   /// \brief Retrieve the name of the named (primary) AST file
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 0241b22f9e..1b351a30dc 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -2764,9 +2764,8 @@ ASTReader::ASTReadResult ASTReader::ReadASTCore(StringRef FileName,
     if (CurrentDir.empty()) CurrentDir = ".";
   }
 
-  if (!ASTBuffers.empty()) {
-    F.Buffer.reset(ASTBuffers.back());
-    ASTBuffers.pop_back();
+  if (llvm::MemoryBuffer *Buffer = ModuleMgr.lookupBuffer(FileName)) {
+    F.Buffer.reset(Buffer);
     assert(F.Buffer && "Passed null buffer");
   } else {
     // Open the AST file.
@@ -5586,6 +5585,11 @@ Module *ModuleManager::lookup(StringRef Name) {
   return Modules[Entry];
 }
 
+llvm::MemoryBuffer *ModuleManager::lookupBuffer(StringRef Name) {
+  const FileEntry *Entry = FileMgr.getFile(Name);
+  return InMemoryBuffers[Entry];
+}
+
 /// \brief Creates a new module and adds it to the list of known modules
 Module &ModuleManager::addModule(StringRef FileName, ModuleKind Type) {
   Module *Prev = !size() ? 0 : &getLastModule();
@@ -5605,6 +5609,13 @@ Module &ModuleManager::addModule(StringRef FileName, ModuleKind Type) {
   return *Current;
 }
 
+void ModuleManager::addInMemoryBuffer(StringRef FileName, 
+  llvm::MemoryBuffer *Buffer) {
+  
+  const FileEntry *Entry = FileMgr.getVirtualFile(FileName, 
+    Buffer->getBufferSize(), 0);
+  InMemoryBuffers[Entry] = Buffer;
+}
 /// \brief Exports the list of loaded modules with their corresponding names
 void ModuleManager::exportLookup(SmallVector<ModuleOffset, 16> &Target) {
   Target.reserve(size());
diff --git a/lib/Serialization/ChainedIncludesSource.cpp b/lib/Serialization/ChainedIncludesSource.cpp
index a4a9f08f99..000e76846e 100644
--- a/lib/Serialization/ChainedIncludesSource.cpp
+++ b/lib/Serialization/ChainedIncludesSource.cpp
@@ -26,15 +26,18 @@
 using namespace clang;
 
 static ASTReader *createASTReader(CompilerInstance &CI,
-                                  StringRef pchFile,
-                                  llvm::MemoryBuffer **memBufs,
-                                  unsigned numBufs,
+                                  StringRef pchFile,  
+                                  SmallVector<llvm::MemoryBuffer *, 4> &memBufs,
+                                  SmallVector<std::string, 4> &bufNames,
                              ASTDeserializationListener *deserialListener = 0) {
   Preprocessor &PP = CI.getPreprocessor();
   llvm::OwningPtr<ASTReader> Reader;
   Reader.reset(new ASTReader(PP, &CI.getASTContext(), /*isysroot=*/"",
                              /*DisableValidation=*/true));
-  Reader->setASTMemoryBuffers(memBufs, numBufs);
+  for (unsigned ti = 0; ti < bufNames.size(); ++ti) {
+    StringRef sr(bufNames[ti]);
+    Reader->addInMemoryBuffer(sr, memBufs[ti]);
+  }
   Reader->setDeserializationListener(deserialListener);
   switch (Reader->ReadAST(pchFile, serialization::MK_PCH)) {
   case ASTReader::Success:
@@ -63,6 +66,7 @@ ChainedIncludesSource *ChainedIncludesSource::create(CompilerInstance &CI) {
   InputKind IK = CI.getFrontendOpts().Inputs[0].first;
 
   SmallVector<llvm::MemoryBuffer *, 4> serialBufs;
+  SmallVector<std::string, 4> serialBufNames;
 
   for (unsigned i = 0, e = includes.size(); i != e; ++i) {
     bool firstInclude = (i == 0);
@@ -125,9 +129,13 @@ ChainedIncludesSource *ChainedIncludesSource::create(CompilerInstance &CI) {
       llvm::raw_string_ostream os(pchName);
       os << ".pch" << i-1;
       os.flush();
+      
+      serialBufNames.push_back(pchName);
+
       llvm::OwningPtr<ExternalASTSource> Reader;
-      Reader.reset(createASTReader(*Clang, pchName, bufs.data(), bufs.size(),
-                      Clang->getASTConsumer().GetASTDeserializationListener()));
+
+      Reader.reset(createASTReader(*Clang, pchName, bufs, serialBufNames, 
+        Clang->getASTConsumer().GetASTDeserializationListener()));
       if (!Reader)
         return 0;
       Clang->getASTContext().setExternalSource(Reader);
@@ -147,9 +155,9 @@ ChainedIncludesSource *ChainedIncludesSource::create(CompilerInstance &CI) {
 
   assert(!serialBufs.empty());
   std::string pchName = includes.back() + ".pch-final";
+  serialBufNames.push_back(pchName);
   llvm::OwningPtr<ASTReader> Reader;
-  Reader.reset(createASTReader(CI, pchName,
-                               serialBufs.data(), serialBufs.size()));
+  Reader.reset(createASTReader(CI, pchName, serialBufs, serialBufNames));
   if (!Reader)
     return 0;