[modules] Consistently construct a buffer as input to build the module.

This means the main file for modules will always be a virtual one.

llvm-svn: 165591

clang/include/clang/Basic/Module.h

@@ -290,6 +290,10 @@ public:
   submodule_iterator submodule_end()   { return SubModules.end(); }
   submodule_const_iterator submodule_end() const { return SubModules.end(); }
   
+  static StringRef getModuleInputBufferName() {
+    return "<module-includes>";
+  }
+
   /// \brief Print the module map for this module to the given stream. 
   ///
   void print(llvm::raw_ostream &OS, unsigned Indent = 0) const;

clang/lib/Frontend/FrontendActions.cpp

@@ -131,6 +131,29 @@ ASTConsumer *GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
                           Sysroot, OS);
 }
 
+static SmallVectorImpl<char> &
+operator+=(SmallVectorImpl<char> &Includes, StringRef RHS) {
+  Includes.append(RHS.begin(), RHS.end());
+  return Includes;
+}
+
+static void addHeaderInclude(StringRef HeaderName,
+                             SmallVectorImpl<char> &Includes,
+                             const LangOptions &LangOpts) {
+  if (LangOpts.ObjC1)
+    Includes += "#import \"";
+  else
+    Includes += "#include \"";
+  Includes += HeaderName;
+  Includes += "\"\n";
+}
+
+static void addHeaderInclude(const FileEntry *Header,
+                             SmallVectorImpl<char> &Includes,
+                             const LangOptions &LangOpts) {
+  addHeaderInclude(Header->getName(), Includes, LangOpts);
+}
+
 /// \brief Collect the set of header includes needed to construct the given 
 /// module and update the TopHeaders file set of the module.
 ///
@@ -142,7 +165,7 @@ static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
                                         FileManager &FileMgr,
                                         ModuleMap &ModMap,
                                         clang::Module *Module,
-                                        SmallString<256> &Includes) {
+                                        SmallVectorImpl<char> &Includes) {
   // Don't collect any headers for unavailable modules.
   if (!Module->isAvailable())
     return;
@@ -151,24 +174,14 @@ static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
   for (unsigned I = 0, N = Module->Headers.size(); I != N; ++I) {
     const FileEntry *Header = Module->Headers[I];
     Module->TopHeaders.insert(Header);
-    if (LangOpts.ObjC1)
-      Includes += "#import \"";
-    else
-      Includes += "#include \"";
-    Includes += Header->getName();
-    Includes += "\"\n";
+    addHeaderInclude(Header, Includes, LangOpts);
   }
 
   if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader()) {
     Module->TopHeaders.insert(UmbrellaHeader);
     if (Module->Parent) {
       // Include the umbrella header for submodules.
-      if (LangOpts.ObjC1)
-        Includes += "#import \"";
-      else
-        Includes += "#include \"";
-      Includes += UmbrellaHeader->getName();
-      Includes += "\"\n";
+      addHeaderInclude(UmbrellaHeader, Includes, LangOpts);
     }
   } else if (const DirectoryEntry *UmbrellaDir = Module->getUmbrellaDir()) {
     // Add all of the headers we find in this subdirectory.
@@ -194,12 +207,7 @@ static void collectModuleHeaderIncludes(const LangOptions &LangOpts,
       }
       
       // Include this header umbrella header for submodules.
-      if (LangOpts.ObjC1)
-        Includes += "#import \"";
-      else
-        Includes += "#include \"";
-      Includes += Dir->path();
-      Includes += "\"\n";
+      addHeaderInclude(Dir->path(), Includes, LangOpts);
     }
   }
   
@@ -255,77 +263,29 @@ bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI,
     return false;
   }
 
-  // Do we have an umbrella header for this module?
-  const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader();
-  
+  FileManager &FileMgr = CI.getFileManager();
+
   // Collect the set of #includes we need to build the module.
   SmallString<256> HeaderContents;
-  collectModuleHeaderIncludes(CI.getLangOpts(), CI.getFileManager(),
+  if (const FileEntry *UmbrellaHeader = Module->getUmbrellaHeader())
+    addHeaderInclude(UmbrellaHeader, HeaderContents, CI.getLangOpts());
+  collectModuleHeaderIncludes(CI.getLangOpts(), FileMgr,
     CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(),
     Module, HeaderContents);
-  if (UmbrellaHeader && HeaderContents.empty()) {
-    // Simple case: we have an umbrella header and there are no additional
-    // includes, we can just parse the umbrella header directly.
-    setCurrentInput(FrontendInputFile(UmbrellaHeader->getName(),
-                                      getCurrentFileKind(),
-                                      Module->IsSystem));
-    return true;
-  }
-  
-  FileManager &FileMgr = CI.getFileManager();
-  SmallString<128> HeaderName;
-  time_t ModTime;
-  if (UmbrellaHeader) {
-    // Read in the umbrella header.
-    // FIXME: Go through the source manager; the umbrella header may have
-    // been overridden.
-    std::string ErrorStr;
-    llvm::MemoryBuffer *UmbrellaContents
-      = FileMgr.getBufferForFile(UmbrellaHeader, &ErrorStr);
-    if (!UmbrellaContents) {
-      CI.getDiagnostics().Report(diag::err_missing_umbrella_header)
-        << UmbrellaHeader->getName() << ErrorStr;
-      return false;
-    }
-    
-    // Combine the contents of the umbrella header with the automatically-
-    // generated includes.
-    SmallString<256> OldContents = HeaderContents;
-    HeaderContents = UmbrellaContents->getBuffer();
-    HeaderContents += "\n\n";
-    HeaderContents += "/* Module includes */\n";
-    HeaderContents += OldContents;
 
-    // Pretend that we're parsing the umbrella header.
-    HeaderName = UmbrellaHeader->getName();
-    ModTime = UmbrellaHeader->getModificationTime();
-    
-    delete UmbrellaContents;
-  } else {
-    // Pick an innocuous-sounding name for the umbrella header.
-    HeaderName = Module->Name + ".h";
-    if (FileMgr.getFile(HeaderName, /*OpenFile=*/false, 
-                        /*CacheFailure=*/false)) {
-      // Try again!
-      HeaderName = Module->Name + "-module.h";      
-      if (FileMgr.getFile(HeaderName, /*OpenFile=*/false, 
-                          /*CacheFailure=*/false)) {
-        // Pick something ridiculous and go with it.
-        HeaderName = Module->Name + "-module.hmod";
-      }
-    }
-    ModTime = time(0);
-  }
-  
-  // Remap the contents of the header name we're using to our synthesized
-  // buffer.
-  const FileEntry *HeaderFile = FileMgr.getVirtualFile(HeaderName, 
+  StringRef InputName = Module::getModuleInputBufferName();
+
+  // We consistently construct a buffer as input to build the module.
+  // This means the main file for modules will always be a virtual one.
+  // FIXME: Maybe allow using a memory buffer as input directly instead of
+  // messing with virtual files.
+  const FileEntry *HeaderFile = FileMgr.getVirtualFile(InputName, 
                                                        HeaderContents.size(), 
-                                                       ModTime);
+                                                       time(0));
   llvm::MemoryBuffer *HeaderContentsBuf
     = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
   CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);  
-  setCurrentInput(FrontendInputFile(HeaderName, getCurrentFileKind(),
+  setCurrentInput(FrontendInputFile(InputName, getCurrentFileKind(),
                                     Module->IsSystem));
   return true;
 }

clang/lib/Serialization/ASTReader.cpp

@@ -1111,7 +1111,7 @@ ASTReader::ASTReadResult ASTReader::ReadSLocEntryRecord(int ID) {
       return Failure;
     }
 
-    if (!DisableValidation &&
+    if (!DisableValidation && !OverriddenBuffer &&
         ((off_t)Record[4] != File->getSize()
 #if !defined(LLVM_ON_WIN32)
         // In our regression testing, the Windows file system seems to