<rdar://problem/13479539> Simplify ModuleManager/GlobalModuleIndex interaction to eliminate a pile of extraneous stats().

The refactoring in r177367 introduced a serious performance bug where
the "lazy" resolution of module file names in the global module index
to actual module file entries in the module manager would perform
repeated negative stats(). The new interaction requires the module
manager to inform the global module index when a module file has been
loaded, eliminating the extraneous stat()s and a bunch of bookkeeping
on both sides.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177750 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 11 deletions

diff --git a/include/clang/Serialization/ModuleManager.h b/include/clang/Serialization/ModuleManager.h
index 9b58b75ebb..c6e3265b3b 100644
--- a/include/clang/Serialization/ModuleManager.h
+++ b/include/clang/Serialization/ModuleManager.h
@@ -16,18 +16,18 @@
 #define LLVM_CLANG_SERIALIZATION_MODULE_MANAGER_H
 
 #include "clang/Basic/FileManager.h"
-#include "clang/Serialization/GlobalModuleIndex.h"
 #include "clang/Serialization/Module.h"
 #include "llvm/ADT/DenseMap.h"
 
 namespace clang { 
 
+class GlobalModuleIndex;
 class ModuleMap;
 
 namespace serialization {
-  
+
 /// \brief Manages the set of modules loaded by an AST reader.
-class ModuleManager : public ModuleFileNameResolver {
+class ModuleManager {
   /// \brief The chain of AST files. The first entry is the one named by the
   /// user, the last one is the one that doesn't depend on anything further.
   SmallVector<ModuleFile *, 2> Chain;
@@ -61,9 +61,6 @@ class ModuleManager : public ModuleFileNameResolver {
   /// just an non-owning pointer.
   GlobalModuleIndex *GlobalIndex;
 
-  /// \brief Update the set of modules files we know about known to the global index.
-  void updateModulesInCommonWithGlobalIndex();
-
   /// \brief State used by the "visit" operation to avoid malloc traffic in
   /// calls to visit().
   struct VisitState {
@@ -202,6 +199,10 @@ public:
   /// \brief Set the global module index.
   void setGlobalIndex(GlobalModuleIndex *Index);
 
+  /// \brief Notification from the AST reader that the given module file
+  /// has been "accepted", and will not (can not) be unloaded.
+  void moduleFileAccepted(ModuleFile *MF);
+
   /// \brief Visit each of the modules.
   ///
   /// This routine visits each of the modules, starting with the
@@ -270,11 +271,6 @@ public:
                         time_t ExpectedModTime,
                         const FileEntry *&File);
 
-  virtual bool resolveModuleFileName(StringRef FileName,
-                                     off_t ExpectedSize,
-                                     time_t ExpectedModTime,
-                                     ModuleFile *&File);
-
   /// \brief View the graphviz representation of the module graph.
   void viewGraph();
 };