Rework the external Sema source's ReadMethodPool() so that it doesn't

return pre-built lists. Instead, it feeds the methods it deserializes
to Sema so that Sema can unique them, which keeps the chains shorter.

llvm-svn: 148889

clang/include/clang/Frontend/ChainedIncludesSource.h

@@ -66,7 +66,7 @@ protected:
 
   virtual void InitializeSema(Sema &S);
   virtual void ForgetSema();
-  virtual std::pair<ObjCMethodList,ObjCMethodList> ReadMethodPool(Selector Sel);
+  virtual void ReadMethodPool(Selector Sel);
   virtual bool LookupUnqualified(LookupResult &R, Scope *S);
 };
 

clang/include/clang/Sema/ExternalSemaSource.h

@@ -59,10 +59,7 @@ public:
 
   /// \brief Load the contents of the global method pool for a given
   /// selector.
-  ///
-  /// \returns a pair of Objective-C methods lists containing the
-  /// instance and factory methods, respectively, with this selector.
-  virtual std::pair<ObjCMethodList,ObjCMethodList> ReadMethodPool(Selector Sel);
+  virtual void ReadMethodPool(Selector Sel);
 
   /// \brief Load the set of namespaces that are known to the external source,
   /// which will be used during typo correction.

clang/include/clang/Sema/Sema.h

@@ -650,7 +650,7 @@ public:
   /// of -Wselector.
   llvm::DenseMap<Selector, SourceLocation> ReferencedSelectors;
 
-  GlobalMethodPool::iterator ReadMethodPool(Selector Sel);
+  void ReadMethodPool(Selector Sel);
 
   /// Private Helper predicate to check for 'self'.
   bool isSelfExpr(Expr *RExpr);
@@ -1963,6 +1963,9 @@ public:
   /// warns each time an exact match is found.
   void CheckCategoryVsClassMethodMatches(ObjCCategoryImplDecl *CatIMP);
 
+  /// \brief Add the given method to the list of globally-known methods.
+  void addMethodToGlobalList(ObjCMethodList *List, ObjCMethodDecl *Method);
+  
 private:
   /// AddMethodToGlobalPool - Add an instance or factory method to the global
   /// pool. See descriptoin of AddInstanceMethodToGlobalPool.

clang/include/clang/Serialization/ASTReader.h

@@ -1197,11 +1197,7 @@ public:
 
   /// \brief Load the contents of the global method pool for a given
   /// selector.
-  ///
-  /// \returns a pair of Objective-C methods lists containing the
-  /// instance and factory methods, respectively, with this selector.
-  virtual std::pair<ObjCMethodList, ObjCMethodList>
-    ReadMethodPool(Selector Sel);
+  virtual void ReadMethodPool(Selector Sel);
 
   /// \brief Load the set of namespaces that are known to the external source,
   /// which will be used during typo correction.

clang/lib/Frontend/ChainedIncludesSource.cpp

@@ -231,9 +231,8 @@ void ChainedIncludesSource::InitializeSema(Sema &S) {
 void ChainedIncludesSource::ForgetSema() {
   return getFinalReader().ForgetSema();
 }
-std::pair<ObjCMethodList,ObjCMethodList>
-ChainedIncludesSource::ReadMethodPool(Selector Sel) {
-  return getFinalReader().ReadMethodPool(Sel);
+void ChainedIncludesSource::ReadMethodPool(Selector Sel) {
+  getFinalReader().ReadMethodPool(Sel);
 }
 bool ChainedIncludesSource::LookupUnqualified(LookupResult &R, Scope *S) {
   return getFinalReader().LookupUnqualified(R, S);

clang/lib/Sema/Sema.cpp

@@ -879,10 +879,7 @@ LambdaScopeInfo *Sema::getCurLambda() {
 // Pin this vtable to this file.
 ExternalSemaSource::~ExternalSemaSource() {}
 
-std::pair<ObjCMethodList, ObjCMethodList>
-ExternalSemaSource::ReadMethodPool(Selector Sel) {
-  return std::pair<ObjCMethodList, ObjCMethodList>();
-}
+void ExternalSemaSource::ReadMethodPool(Selector Sel) { }
 
 void ExternalSemaSource::ReadKnownNamespaces(
                            SmallVectorImpl<NamespaceDecl *> &Namespaces) {  

clang/lib/Sema/SemaDeclObjC.cpp

@@ -1931,9 +1931,7 @@ bool Sema::MatchTwoMethodDeclarations(const ObjCMethodDecl *left,
   return true;
 }
 
-/// \brief Add the given method to the given list of globally-known methods.
-static void addMethodToGlobalList(Sema &S, ObjCMethodList *List,
-                                  ObjCMethodDecl *Method) {
+void Sema::addMethodToGlobalList(ObjCMethodList *List, ObjCMethodDecl *Method) {
   // If the list is empty, make it a singleton list.
   if (List->Method == 0) {
     List->Method = Method;
@@ -1945,7 +1943,7 @@ static void addMethodToGlobalList(Sema &S, ObjCMethodList *List,
   // signature.
   ObjCMethodList *Previous = List;
   for (; List; Previous = List, List = List->Next) {
-    if (!S.MatchTwoMethodDeclarations(Method, List->Method))
+    if (!MatchTwoMethodDeclarations(Method, List->Method))
       continue;
     
     ObjCMethodDecl *PrevObjCMethod = List->Method;
@@ -1972,33 +1970,27 @@ static void addMethodToGlobalList(Sema &S, ObjCMethodList *List,
   
   // We have a new signature for an existing method - add it.
   // This is extremely rare. Only 1% of Cocoa selectors are "overloaded".
-  ObjCMethodList *Mem = S.BumpAlloc.Allocate<ObjCMethodList>();
+  ObjCMethodList *Mem = BumpAlloc.Allocate<ObjCMethodList>();
   Previous->Next = new (Mem) ObjCMethodList(Method, 0);
 }
 
 /// \brief Read the contents of the method pool for a given selector from
 /// external storage.
-///
-/// This routine should only be called once, when the method pool has no entry
-/// for this selector.
-Sema::GlobalMethodPool::iterator Sema::ReadMethodPool(Selector Sel) {
+void Sema::ReadMethodPool(Selector Sel) {
   assert(ExternalSource && "We need an external AST source");
-  assert(MethodPool.find(Sel) == MethodPool.end() &&
-         "Selector data already loaded into the method pool");
-
-  // Read the method list from the external source.
-  GlobalMethods Methods = ExternalSource->ReadMethodPool(Sel);
-
-  return MethodPool.insert(std::make_pair(Sel, Methods)).first;
+  ExternalSource->ReadMethodPool(Sel);
 }
 
 void Sema::AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl,
                                  bool instance) {
   GlobalMethodPool::iterator Pos = MethodPool.find(Method->getSelector());
   if (Pos == MethodPool.end()) {
-    if (ExternalSource)
-      Pos = ReadMethodPool(Method->getSelector());
-    else
+    if (ExternalSource) {
+      ReadMethodPool(Method->getSelector());
+      Pos = MethodPool.find(Method->getSelector());
+    }
+    
+    if (Pos == MethodPool.end())
       Pos = MethodPool.insert(std::make_pair(Method->getSelector(),
                                              GlobalMethods())).first;
   }
@@ -2006,7 +1998,7 @@ void Sema::AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl,
   Method->setDefined(impl);
   
   ObjCMethodList &Entry = instance ? Pos->second.first : Pos->second.second;
-  addMethodToGlobalList(*this, &Entry, Method);
+  addMethodToGlobalList(&Entry, Method);
 }
 
 /// Determines if this is an "acceptable" loose mismatch in the global
@@ -2033,9 +2025,14 @@ ObjCMethodDecl *Sema::LookupMethodInGlobalPool(Selector Sel, SourceRange R,
                                                bool warn, bool instance) {
   GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
   if (Pos == MethodPool.end()) {
-    if (ExternalSource)
-      Pos = ReadMethodPool(Sel);
-    else
+    if (ExternalSource) {
+      ReadMethodPool(Sel);
+      
+      Pos = MethodPool.find(Sel);
+      if (Pos == MethodPool.end())
+        return 0;
+      
+    } else
       return 0;
   }
 
@@ -2497,7 +2494,11 @@ public:
     Sema::GlobalMethodPool::iterator it = S.MethodPool.find(selector);
     if (it == S.MethodPool.end()) {
       if (!S.ExternalSource) return;
-      it = S.ReadMethodPool(selector);
+      S.ReadMethodPool(selector);
+      
+      it = S.MethodPool.find(selector);
+      if (it == S.MethodPool.end())
+        return;
     }
     ObjCMethodList &list =
       method->isInstanceMethod() ? it->second.first : it->second.second;

clang/lib/Serialization/ASTReader.cpp

@@ -5216,30 +5216,6 @@ namespace clang { namespace serialization {
     llvm::SmallVector<ObjCMethodDecl *, 4> InstanceMethods;
     llvm::SmallVector<ObjCMethodDecl *, 4> FactoryMethods;
 
-    /// \brief Build an ObjCMethodList from a vector of Objective-C method
-    /// declarations.
-    ObjCMethodList 
-    buildObjCMethodList(const SmallVectorImpl<ObjCMethodDecl *> &Vec) const
-    {
-      ObjCMethodList List;
-      ObjCMethodList *Prev = 0;
-      for (unsigned I = 0, N = Vec.size(); I != N; ++I) {
-        if (!List.Method) {
-          // This is the first method, which is the easy case.
-          List.Method = Vec[I];
-          Prev = &List;
-          continue;
-        }
-        
-        ObjCMethodList *Mem =
-          Reader.getSema()->BumpAlloc.Allocate<ObjCMethodList>();
-        Prev->Next = new (Mem) ObjCMethodList(Vec[I], 0);
-        Prev = Prev->Next;
-      }
-      
-      return List;
-    }
-    
   public:
     ReadMethodPoolVisitor(ASTReader &Reader, Selector Sel)
       : Reader(Reader), Sel(Sel) { }
@@ -5273,28 +5249,44 @@ namespace clang { namespace serialization {
     }
     
     /// \brief Retrieve the instance methods found by this visitor.
-    ObjCMethodList getInstanceMethods() const { 
-      return buildObjCMethodList(InstanceMethods); 
+    ArrayRef<ObjCMethodDecl *> getInstanceMethods() const { 
+      return InstanceMethods; 
     }
 
     /// \brief Retrieve the instance methods found by this visitor.
-    ObjCMethodList getFactoryMethods() const { 
-      return buildObjCMethodList(FactoryMethods); 
+    ArrayRef<ObjCMethodDecl *> getFactoryMethods() const { 
+      return FactoryMethods;
     }
   };
 } } // end namespace clang::serialization
 
-std::pair<ObjCMethodList, ObjCMethodList>
-ASTReader::ReadMethodPool(Selector Sel) {
+/// \brief Add the given set of methods to the method list.
+static void addMethodsToPool(Sema &S, ArrayRef<ObjCMethodDecl *> Methods,
+                             ObjCMethodList &List) {
+  for (unsigned I = 0, N = Methods.size(); I != N; ++I) {
+    S.addMethodToGlobalList(&List, Methods[I]);
+  }
+}
+                             
+void ASTReader::ReadMethodPool(Selector Sel) {
   ReadMethodPoolVisitor Visitor(*this, Sel);
   ModuleMgr.visit(&ReadMethodPoolVisitor::visit, &Visitor);
-  std::pair<ObjCMethodList, ObjCMethodList> Result;
-  Result.first = Visitor.getInstanceMethods();
-  Result.second = Visitor.getFactoryMethods();
   
-  if (!Result.first.Method && !Result.second.Method)
+  if (Visitor.getInstanceMethods().empty() &&
+      Visitor.getFactoryMethods().empty()) {
     ++NumMethodPoolMisses;
-  return Result;
+    return;
+  }
+  
+  if (!getSema())
+    return;
+  
+  Sema &S = *getSema();
+  Sema::GlobalMethodPool::iterator Pos
+    = S.MethodPool.insert(std::make_pair(Sel, Sema::GlobalMethods())).first;
+  
+  addMethodsToPool(S, Visitor.getInstanceMethods(), Pos->second.first);
+  addMethodsToPool(S, Visitor.getFactoryMethods(), Pos->second.second);
 }
 
 void ASTReader::ReadKnownNamespaces(