[AST] Turn the callbacks of lookupInBases and forallBases into a function_ref

This lets us pass functors (and lambdas) without void * tricks. On the
downside we can't pass CXXRecordDecl's Find* members (which are now type
safe) to lookupInBases directly, but a lambda trampoline is a small
price to pay. No functionality change intended.

llvm-svn: 243217

1 files changed, 36 insertions, 41 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 0eea0e689dc..661edc74c5e 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -6500,50 +6500,45 @@ bool Sema::CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous) {
   return false;
 }
 
-/// \brief Data used with FindOverriddenMethod
-struct FindOverriddenMethodData {
+namespace {
+struct FindOverriddenMethod {
   Sema *S;
   CXXMethodDecl *Method;
-};
 
-/// \brief Member lookup function that determines whether a given C++
-/// method overrides a method in a base class, to be used with
-/// CXXRecordDecl::lookupInBases().
-static bool FindOverriddenMethod(const CXXBaseSpecifier *Specifier,
-                                 CXXBasePath &Path,
-                                 void *UserData) {
-  RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
+  /// Member lookup function that determines whether a given C++
+  /// method overrides a method in a base class, to be used with
+  /// CXXRecordDecl::lookupInBases().
+  bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
+    RecordDecl *BaseRecord =
+        Specifier->getType()->getAs<RecordType>()->getDecl();
 
-  FindOverriddenMethodData *Data 
-    = reinterpret_cast<FindOverriddenMethodData*>(UserData);
-  
-  DeclarationName Name = Data->Method->getDeclName();
-  
-  // FIXME: Do we care about other names here too?
-  if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
-    // We really want to find the base class destructor here.
-    QualType T = Data->S->Context.getTypeDeclType(BaseRecord);
-    CanQualType CT = Data->S->Context.getCanonicalType(T);
-    
-    Name = Data->S->Context.DeclarationNames.getCXXDestructorName(CT);
-  }    
-  
-  for (Path.Decls = BaseRecord->lookup(Name);
-       !Path.Decls.empty();
-       Path.Decls = Path.Decls.slice(1)) {
-    NamedDecl *D = Path.Decls.front();
-    if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
-      if (MD->isVirtual() && !Data->S->IsOverload(Data->Method, MD, false))
-        return true;
+    DeclarationName Name = Method->getDeclName();
+
+    // FIXME: Do we care about other names here too?
+    if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
+      // We really want to find the base class destructor here.
+      QualType T = S->Context.getTypeDeclType(BaseRecord);
+      CanQualType CT = S->Context.getCanonicalType(T);
+
+      Name = S->Context.DeclarationNames.getCXXDestructorName(CT);
+    }
+
+    for (Path.Decls = BaseRecord->lookup(Name); !Path.Decls.empty();
+         Path.Decls = Path.Decls.slice(1)) {
+      NamedDecl *D = Path.Decls.front();
+      if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
+        if (MD->isVirtual() && !S->IsOverload(Method, MD, false))
+          return true;
+      }
     }
+
+    return false;
   }
-  
-  return false;
-}
+};
+
+enum OverrideErrorKind { OEK_All, OEK_NonDeleted, OEK_Deleted };
+} // end anonymous namespace
 
-namespace {
-  enum OverrideErrorKind { OEK_All, OEK_NonDeleted, OEK_Deleted };
-}
 /// \brief Report an error regarding overriding, along with any relevant
 /// overriden methods.
 ///
@@ -6571,13 +6566,13 @@ static void ReportOverrides(Sema& S, unsigned DiagID, const CXXMethodDecl *MD,
 bool Sema::AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) {
   // Look for methods in base classes that this method might override.
   CXXBasePaths Paths;
-  FindOverriddenMethodData Data;
-  Data.Method = MD;
-  Data.S = this;
+  FindOverriddenMethod FOM;
+  FOM.Method = MD;
+  FOM.S = this;
   bool hasDeletedOverridenMethods = false;
   bool hasNonDeletedOverridenMethods = false;
   bool AddedAny = false;
-  if (DC->lookupInBases(&FindOverriddenMethod, &Data, Paths)) {
+  if (DC->lookupInBases(FOM, Paths)) {
     for (auto *I : Paths.found_decls()) {
       if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(I)) {
         MD->addOverriddenMethod(OldMD->getCanonicalDecl());