[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, 69 insertions, 56 deletions

diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index d2fdd4fec6..02430e6da5 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -2444,19 +2444,10 @@ bool containsInvalidMethodImplAttribute(ObjCMethodDecl *IMD,
   return false;
 }
 
-namespace  {
-  /// \brief Describes the compatibility of a result type with its method.
-  enum ResultTypeCompatibilityKind {
-    RTC_Compatible,
-    RTC_Incompatible,
-    RTC_Unknown
-  };
-}
-
 /// \brief Check whether the declared result type of the given Objective-C
 /// method declaration is compatible with the method's class.
 ///
-static ResultTypeCompatibilityKind 
+static Sema::ResultTypeCompatibilityKind 
 CheckRelatedResultTypeCompatibility(Sema &S, ObjCMethodDecl *Method,
                                     ObjCInterfaceDecl *CurrentClass) {
   QualType ResultType = Method->getResultType();
@@ -2469,27 +2460,27 @@ CheckRelatedResultTypeCompatibility(Sema &S, ObjCMethodDecl *Method,
     //   - it is id or qualified id, or
     if (ResultObjectType->isObjCIdType() ||
         ResultObjectType->isObjCQualifiedIdType())
-      return RTC_Compatible;
+      return Sema::RTC_Compatible;
   
     if (CurrentClass) {
       if (ObjCInterfaceDecl *ResultClass 
                                       = ResultObjectType->getInterfaceDecl()) {
         //   - it is the same as the method's class type, or
         if (declaresSameEntity(CurrentClass, ResultClass))
-          return RTC_Compatible;
+          return Sema::RTC_Compatible;
         
         //   - it is a superclass of the method's class type
         if (ResultClass->isSuperClassOf(CurrentClass))
-          return RTC_Compatible;
+          return Sema::RTC_Compatible;
       }      
     } else {
       // Any Objective-C pointer type might be acceptable for a protocol
       // method; we just don't know.
-      return RTC_Unknown;
+      return Sema::RTC_Unknown;
     }
   }
   
-  return RTC_Incompatible;
+  return Sema::RTC_Incompatible;
 }
 
 namespace {
@@ -2639,6 +2630,67 @@ private:
 };
 }
 
+void Sema::CheckObjCMethodOverrides(ObjCMethodDecl *ObjCMethod,
+                                    ObjCInterfaceDecl *CurrentClass,
+                                    ResultTypeCompatibilityKind RTC) {
+  // Search for overridden methods and merge information down from them.
+  OverrideSearch overrides(*this, ObjCMethod);
+  // Keep track if the method overrides any method in the class's base classes,
+  // its protocols, or its categories' protocols; we will keep that info
+  // in the ObjCMethodDecl.
+  // For this info, a method in an implementation is not considered as
+  // overriding the same method in the interface or its categories.
+  bool hasOverriddenMethodsInBaseOrProtocol = false;
+  for (OverrideSearch::iterator
+         i = overrides.begin(), e = overrides.end(); i != e; ++i) {
+    ObjCMethodDecl *overridden = *i;
+
+    if (isa<ObjCProtocolDecl>(overridden->getDeclContext()) ||
+        CurrentClass != overridden->getClassInterface() ||
+        overridden->isOverriding())
+      hasOverriddenMethodsInBaseOrProtocol = true;
+
+    // Propagate down the 'related result type' bit from overridden methods.
+    if (RTC != Sema::RTC_Incompatible && overridden->hasRelatedResultType())
+      ObjCMethod->SetRelatedResultType();
+
+    // Then merge the declarations.
+    mergeObjCMethodDecls(ObjCMethod, overridden);
+
+    if (ObjCMethod->isImplicit() && overridden->isImplicit())
+      continue; // Conflicting properties are detected elsewhere.
+
+    // Check for overriding methods
+    if (isa<ObjCInterfaceDecl>(ObjCMethod->getDeclContext()) || 
+        isa<ObjCImplementationDecl>(ObjCMethod->getDeclContext()))
+      CheckConflictingOverridingMethod(ObjCMethod, overridden,
+              isa<ObjCProtocolDecl>(overridden->getDeclContext()));
+    
+    if (CurrentClass && overridden->getDeclContext() != CurrentClass &&
+        isa<ObjCInterfaceDecl>(overridden->getDeclContext())) {
+      ObjCMethodDecl::param_iterator ParamI = ObjCMethod->param_begin(),
+                                          E = ObjCMethod->param_end();
+      ObjCMethodDecl::param_iterator PrevI = overridden->param_begin();
+      for (; ParamI != E; ++ParamI, ++PrevI) {
+        // Number of parameters are the same and is guaranteed by selector match.
+        assert(PrevI != overridden->param_end() && "Param mismatch");
+        QualType T1 = Context.getCanonicalType((*ParamI)->getType());
+        QualType T2 = Context.getCanonicalType((*PrevI)->getType());
+        // If type of argument of method in this class does not match its
+        // respective argument type in the super class method, issue warning;
+        if (!Context.typesAreCompatible(T1, T2)) {
+          Diag((*ParamI)->getLocation(), diag::ext_typecheck_base_super)
+            << T1 << T2;
+          Diag(overridden->getLocation(), diag::note_previous_declaration);
+          break;
+        }
+      }
+    }
+  }
+
+  ObjCMethod->setOverriding(hasOverriddenMethodsInBaseOrProtocol);
+}
+
 Decl *Sema::ActOnMethodDeclaration(
     Scope *S,
     SourceLocation MethodLoc, SourceLocation EndLoc,
@@ -2828,53 +2880,14 @@ Decl *Sema::ActOnMethodDeclaration(
   ResultTypeCompatibilityKind RTC
     = CheckRelatedResultTypeCompatibility(*this, ObjCMethod, CurrentClass);
 
-  // Search for overridden methods and merge information down from them.
-  OverrideSearch overrides(*this, ObjCMethod);
-  for (OverrideSearch::iterator
-         i = overrides.begin(), e = overrides.end(); i != e; ++i) {
-    ObjCMethodDecl *overridden = *i;
-
-    // Propagate down the 'related result type' bit from overridden methods.
-    if (RTC != RTC_Incompatible && overridden->hasRelatedResultType())
-      ObjCMethod->SetRelatedResultType();
+  CheckObjCMethodOverrides(ObjCMethod, CurrentClass, RTC);
 
-    // Then merge the declarations.
-    mergeObjCMethodDecls(ObjCMethod, overridden);
-    
-    // Check for overriding methods
-    if (isa<ObjCInterfaceDecl>(ObjCMethod->getDeclContext()) || 
-        isa<ObjCImplementationDecl>(ObjCMethod->getDeclContext()))
-      CheckConflictingOverridingMethod(ObjCMethod, overridden,
-              isa<ObjCProtocolDecl>(overridden->getDeclContext()));
-    
-    if (CurrentClass && overridden->getDeclContext() != CurrentClass &&
-        isa<ObjCInterfaceDecl>(overridden->getDeclContext())) {
-      ObjCMethodDecl::param_iterator ParamI = ObjCMethod->param_begin(),
-                                          E = ObjCMethod->param_end();
-      ObjCMethodDecl::param_iterator PrevI = overridden->param_begin();
-      for (; ParamI != E; ++ParamI, ++PrevI) {
-        // Number of parameters are the same and is guaranteed by selector match.
-        assert(PrevI != overridden->param_end() && "Param mismatch");
-        QualType T1 = Context.getCanonicalType((*ParamI)->getType());
-        QualType T2 = Context.getCanonicalType((*PrevI)->getType());
-        // If type of argument of method in this class does not match its
-        // respective argument type in the super class method, issue warning;
-        if (!Context.typesAreCompatible(T1, T2)) {
-          Diag((*ParamI)->getLocation(), diag::ext_typecheck_base_super)
-            << T1 << T2;
-          Diag(overridden->getLocation(), diag::note_previous_declaration);
-          break;
-        }
-      }
-    }
-  }
-  
   bool ARCError = false;
   if (getLangOpts().ObjCAutoRefCount)
     ARCError = CheckARCMethodDecl(*this, ObjCMethod);
 
   // Infer the related result type when possible.
-  if (!ARCError && RTC == RTC_Compatible &&
+  if (!ARCError && RTC == Sema::RTC_Compatible &&
       !ObjCMethod->hasRelatedResultType() &&
       LangOpts.ObjCInferRelatedResultType) {
     bool InferRelatedResultType = false;