Index: cfe/trunk/docs/HowToSetupToolingForLLVM.rst
===================================================================
--- cfe/trunk/docs/HowToSetupToolingForLLVM.rst
+++ cfe/trunk/docs/HowToSetupToolingForLLVM.rst
@@ -133,7 +133,8 @@
       if (this->ASTList.operator _Bool())
           return clang::CreateASTDeclNodeLister();
       if (this->ASTDump.operator _Bool())
-          return clang::CreateASTDumper(this->ASTDumpFilter);
+          return clang::CreateASTDumper(nullptr /*Dump to stdout.*/,
+                                        this->ASTDumpFilter);
       if (this->ASTPrint.operator _Bool())
           return clang::CreateASTPrinter(&llvm::outs(), this->ASTDumpFilter);
       return new clang::ASTConsumer();
Index: cfe/trunk/include/clang/Frontend/ASTConsumers.h
===================================================================
--- cfe/trunk/include/clang/Frontend/ASTConsumers.h
+++ cfe/trunk/include/clang/Frontend/ASTConsumers.h
@@ -34,9 +34,10 @@
 std::unique_ptr<ASTConsumer> CreateASTPrinter(std::unique_ptr<raw_ostream> OS,
                                               StringRef FilterString);
 
-// AST dumper: dumps the raw AST in human-readable form to stderr; this is
-// intended for debugging.
-std::unique_ptr<ASTConsumer> CreateASTDumper(StringRef FilterString,
+// AST dumper: dumps the raw AST in human-readable form to the given output
+// stream, or stdout if OS is nullptr.
+std::unique_ptr<ASTConsumer> CreateASTDumper(std::unique_ptr<raw_ostream> OS,
+                                             StringRef FilterString,
                                              bool DumpDecls, bool Deserialize,
                                              bool DumpLookups);
 
Index: cfe/trunk/lib/Frontend/ASTConsumers.cpp
===================================================================
--- cfe/trunk/lib/Frontend/ASTConsumers.cpp
+++ cfe/trunk/lib/Frontend/ASTConsumers.cpp
@@ -138,12 +138,14 @@
                                        FilterString);
 }
 
-std::unique_ptr<ASTConsumer> clang::CreateASTDumper(StringRef FilterString,
-                                                    bool DumpDecls,
-                                                    bool Deserialize,
-                                                    bool DumpLookups) {
+std::unique_ptr<ASTConsumer>
+clang::CreateASTDumper(std::unique_ptr<raw_ostream> Out,
+                       StringRef FilterString,
+                       bool DumpDecls,
+                       bool Deserialize,
+                       bool DumpLookups) {
   assert((DumpDecls || Deserialize || DumpLookups) && "nothing to dump");
-  return llvm::make_unique<ASTPrinter>(nullptr,
+  return llvm::make_unique<ASTPrinter>(std::move(Out),
                                        Deserialize ? ASTPrinter::DumpFull :
                                        DumpDecls ? ASTPrinter::Dump :
                                        ASTPrinter::None,
Index: cfe/trunk/lib/Frontend/FrontendActions.cpp
===================================================================
--- cfe/trunk/lib/Frontend/FrontendActions.cpp
+++ cfe/trunk/lib/Frontend/FrontendActions.cpp
@@ -74,7 +74,8 @@
 
 std::unique_ptr<ASTConsumer>
 ASTDumpAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
-  return CreateASTDumper(CI.getFrontendOpts().ASTDumpFilter,
+  return CreateASTDumper(nullptr /*Dump to stdout.*/,
+                         CI.getFrontendOpts().ASTDumpFilter,
                          CI.getFrontendOpts().ASTDumpDecls,
                          CI.getFrontendOpts().ASTDumpAll,
                          CI.getFrontendOpts().ASTDumpLookups);
Index: cfe/trunk/tools/clang-check/ClangCheck.cpp
===================================================================
--- cfe/trunk/tools/clang-check/ClangCheck.cpp
+++ cfe/trunk/tools/clang-check/ClangCheck.cpp
@@ -138,7 +138,9 @@
     if (ASTList)
       return clang::CreateASTDeclNodeLister();
     if (ASTDump)
-      return clang::CreateASTDumper(ASTDumpFilter, /*DumpDecls=*/true,
+      return clang::CreateASTDumper(nullptr /*Dump to stdout.*/,
+                                    ASTDumpFilter,
+                                    /*DumpDecls=*/true,
                                     /*Deserialize=*/false,
                                     /*DumpLookups=*/false);
     if (ASTPrint)
Index: cfe/trunk/tools/clang-import-test/clang-import-test.cpp
===================================================================
--- cfe/trunk/tools/clang-import-test/clang-import-test.cpp
+++ cfe/trunk/tools/clang-import-test/clang-import-test.cpp
@@ -313,7 +313,8 @@
   auto &CG = *static_cast<CodeGenerator *>(ASTConsumers.back().get());
 
   if (ShouldDumpAST)
-    ASTConsumers.push_back(CreateASTDumper("", true, false, false));
+    ASTConsumers.push_back(CreateASTDumper(nullptr /*Dump to stdout.*/,
+                                           "", true, false, false));
 
   CI.getDiagnosticClient().BeginSourceFile(
       CI.getCompilerInstance().getLangOpts(),