Index: clang/include/clang/AST/PrettyPrinter.h
===================================================================
--- clang/include/clang/AST/PrettyPrinter.h
+++ clang/include/clang/AST/PrettyPrinter.h
@@ -63,7 +63,8 @@
         MSWChar(LO.MicrosoftExt && !LO.WChar), IncludeNewlines(true),
         MSVCFormatting(false), ConstantsAsWritten(false),
         SuppressImplicitBase(false), FullyQualifiedName(false),
-        PrintCanonicalTypes(false), PrintInjectedClassNameWithArguments(true) {}
+        GlobalScopeQualifiedName(false), PrintCanonicalTypes(false),
+        PrintInjectedClassNameWithArguments(true) {}
 
   /// Adjust this printing policy for cases where it's known that we're
   /// printing C++ code (for instance, if AST dumping reaches a C++-only
@@ -241,6 +242,13 @@
   /// This is the opposite of SuppressScope and thus overrules it.
   unsigned FullyQualifiedName : 1;
 
+  // When true, class and struct types (to be expanded if needed) will be
+  // prepended with "::"
+  // Note it also requires `FullyQualifiedName` to also be set to true, as it
+  // does not make sense to prepend "::" to a non fully-qualified name.
+  // This targets generated code.
+  unsigned GlobalScopeQualifiedName : 1;
+
   /// Whether to print types as written or canonically.
   unsigned PrintCanonicalTypes : 1;
 
Index: clang/lib/AST/TypePrinter.cpp
===================================================================
--- clang/lib/AST/TypePrinter.cpp
+++ clang/lib/AST/TypePrinter.cpp
@@ -19,6 +19,7 @@
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/NestedNameSpecifier.h"
+#include "clang/AST/PrettyPrinter.h"
 #include "clang/AST/TemplateBase.h"
 #include "clang/AST/TemplateName.h"
 #include "clang/AST/Type.h"
@@ -40,6 +41,7 @@
 #include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
+#include <iostream>
 #include <string>
 
 using namespace clang;
@@ -320,6 +322,10 @@
       HasEmptyPlaceHolder = false;
   }
 
+  if (Policy.FullyQualifiedName && Policy.GlobalScopeQualifiedName &&
+      T->isStructureOrClassType()) {
+    OS << "::";
+  }
   switch (T->getTypeClass()) {
 #define ABSTRACT_TYPE(CLASS, PARENT)
 #define TYPE(CLASS, PARENT) case Type::CLASS: \