Index: lib/AST/ASTDiagnostic.cpp
===================================================================
--- lib/AST/ASTDiagnostic.cpp
+++ lib/AST/ASTDiagnostic.cpp
@@ -1683,7 +1683,7 @@
       ToName = ToTD->getQualifiedNameAsString();
     }
 
-    if (Same) {
+    if (Same && FromTD) {
       OS << "template " << FromTD->getNameAsString();
     } else if (!PrintTree) {
       OS << (FromDefault ? "(default) template " : "template ");
Index: lib/AST/NestedNameSpecifier.cpp
===================================================================
--- lib/AST/NestedNameSpecifier.cpp
+++ lib/AST/NestedNameSpecifier.cpp
@@ -456,7 +456,9 @@
       Buffer = NewBuffer;
       BufferCapacity = NewCapacity;
     }
-    
+
+    assert(Buffer && "Buffer cannot be NULL");
+
     memcpy(Buffer + BufferSize, Start, End - Start);
     BufferSize += End-Start;
   }
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -2339,7 +2339,7 @@
     success = getAArch64MicroArchFeaturesFromMcpu(D, getAArch64TargetCPU(Args),
                                                   Args, Features);
 
-  if (!success)
+  if (!success && A)
     D.Diag(diag::err_drv_clang_unsupported) << A->getAsString(Args);
 
   if (Args.getLastArg(options::OPT_mgeneral_regs_only)) {
Index: lib/Sema/SemaInit.cpp
===================================================================
--- lib/Sema/SemaInit.cpp
+++ lib/Sema/SemaInit.cpp
@@ -4862,6 +4862,8 @@
                                        InitializationSequence &Sequence,
                                        const InitializedEntity &Entity,
                                        Expr *Initializer) {
+  assert(Initializer && "Initializer needs to be not NULL");
+
   bool ArrayDecay = false;
   QualType ArgType = Initializer->getType();
   QualType ArgPointee;
@@ -5237,11 +5239,11 @@
     DeclAccessPair dap;
     if (isLibstdcxxPointerReturnFalseHack(S, Entity, Initializer)) {
       AddZeroInitializationStep(Entity.getType());
-    } else if (Initializer->getType() == Context.OverloadTy &&
+    } else if (Initializer && Initializer->getType() == Context.OverloadTy &&
                !S.ResolveAddressOfOverloadedFunction(Initializer, DestType,
                                                      false, dap))
       SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
-    else if (Initializer->getType()->isFunctionType() &&
+    else if (Initializer && Initializer->getType()->isFunctionType() &&
              isExprAnUnaddressableFunction(S, Initializer))
       SetFailed(InitializationSequence::FK_AddressOfUnaddressableFunction);
     else