[AST/libclang] Speed up clang_getOverriddenCursors() considerably by reserving a bit

in ObjCMethodDecl to indicate whether the method does not override any other method,
which is the majority of cases.

That way we can avoid unnecessary work doing lookups, especially when PCH is involved.

rdar://11360082

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156476 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 20 insertions, 1 deletions

diff --git a/include/clang/AST/DeclObjC.h b/include/clang/AST/DeclObjC.h
index 4ae073ec46..93441d2e83 100644
--- a/include/clang/AST/DeclObjC.h
+++ b/include/clang/AST/DeclObjC.h
@@ -150,6 +150,15 @@ private:
   /// "standard" position, a enum SelectorLocationsKind.
   unsigned SelLocsKind : 2;
 
+  /// \brief Whether this method overrides any other in the class hierarchy.
+  ///
+  /// A method is said to override any method in the class's
+  /// base classes, its protocols, or its categories' protocols, that has
+  /// the same selector and is of the same kind (class or instance).
+  /// A method in an implementation is not considered as overriding the same
+  /// method in the interface or its categories.
+  unsigned IsOverriding : 1;
+
   // Result type of this method.
   QualType MethodDeclType;
 
@@ -230,7 +239,7 @@ private:
     IsDefined(isDefined), IsRedeclaration(0), HasRedeclaration(0),
     DeclImplementation(impControl), objcDeclQualifier(OBJC_TQ_None),
     RelatedResultType(HasRelatedResultType),
-    SelLocsKind(SelLoc_StandardNoSpace),
+    SelLocsKind(SelLoc_StandardNoSpace), IsOverriding(0),
     MethodDeclType(T), ResultTInfo(ResultTInfo),
     ParamsAndSelLocs(0), NumParams(0),
     EndLoc(endLoc), Body(0), SelfDecl(0), CmdDecl(0) {
@@ -396,6 +405,16 @@ public:
   bool isDefined() const { return IsDefined; }
   void setDefined(bool isDefined) { IsDefined = isDefined; }
 
+  /// \brief Whether this method overrides any other in the class hierarchy.
+  ///
+  /// A method is said to override any method in the class's
+  /// base classes, its protocols, or its categories' protocols, that has
+  /// the same selector and is of the same kind (class or instance).
+  /// A method in an implementation is not considered as overriding the same
+  /// method in the interface or its categories.
+  bool isOverriding() const { return IsOverriding; }
+  void setOverriding(bool isOverriding) { IsOverriding = isOverriding; }
+  
   // Related to protocols declared in  @protocol
   void setDeclImplementation(ImplementationControl ic) {
     DeclImplementation = ic;