Index: include/clang/CrossTU/CrossTranslationUnit.h
===================================================================
--- include/clang/CrossTU/CrossTranslationUnit.h
+++ include/clang/CrossTU/CrossTranslationUnit.h
@@ -108,7 +108,7 @@
   /// Note that the AST files should also be in the \p CrossTUDir.
   llvm::Expected<const FunctionDecl *>
   getCrossTUDefinition(const FunctionDecl *FD, StringRef CrossTUDir,
-                       StringRef IndexName);
+                       StringRef IndexName, bool DisplayCTUProgress = false);
 
   /// This function loads a function definition from an external AST
   ///        file.
@@ -124,7 +124,8 @@
   /// Note that the AST files should also be in the \p CrossTUDir.
   llvm::Expected<ASTUnit *> loadExternalAST(StringRef LookupName,
                                             StringRef CrossTUDir,
-                                            StringRef IndexName);
+                                            StringRef IndexName,
+                                            bool DisplayCTUProgress = false);
 
   /// This function merges a definition from a separate AST Unit into
   ///        the current one which was created by the compiler instance that
Index: include/clang/Driver/CC1Options.td
===================================================================
--- include/clang/Driver/CC1Options.td
+++ include/clang/Driver/CC1Options.td
@@ -84,6 +84,9 @@
   HelpText<"Dump exploded graph to the specified file">;
 def analyzer_dump_egraph_EQ : Joined<["-"], "analyzer-dump-egraph=">, Alias<analyzer_dump_egraph>;
 
+def analyzer_display_ctu_progress : Flag<["-"], "analyzer-display-ctu-progress">,
+  HelpText<"Emit verbose output about the analyzer's progress related to ctu">;
+
 def analyzer_inline_max_stack_depth : Separate<["-"], "analyzer-inline-max-stack-depth">,
   HelpText<"Bound on stack depth while inlining (4 by default)">;
 def analyzer_inline_max_stack_depth_EQ : Joined<["-"], "analyzer-inline-max-stack-depth=">,
Index: include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
===================================================================
--- include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
+++ include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
@@ -200,6 +200,7 @@
   unsigned ShowConfigOptionsList : 1;
   unsigned AnalyzeAll : 1;
   unsigned AnalyzerDisplayProgress : 1;
+  unsigned AnalyzerDisplayCTUProgress : 1;
   unsigned AnalyzeNestedBlocks : 1;
 
   unsigned eagerlyAssumeBinOpBifurcation : 1;
@@ -251,9 +252,10 @@
       : DisableAllChecks(false), ShowCheckerHelp(false),
         ShowEnabledCheckerList(false), ShowConfigOptionsList(false),
         AnalyzeAll(false), AnalyzerDisplayProgress(false),
-        AnalyzeNestedBlocks(false), eagerlyAssumeBinOpBifurcation(false),
-        TrimGraph(false), visualizeExplodedGraphWithGraphViz(false),
-        UnoptimizedCFG(false), PrintStats(false), NoRetryExhausted(false) {}
+        AnalyzerDisplayCTUProgress(false), AnalyzeNestedBlocks(false),
+        eagerlyAssumeBinOpBifurcation(false), TrimGraph(false),
+        visualizeExplodedGraphWithGraphViz(false), UnoptimizedCFG(false),
+        PrintStats(false), NoRetryExhausted(false) {}
 
   /// Interprets an option's string value as a boolean. The "true" string is
   /// interpreted as true and the "false" string is interpreted as false.
Index: lib/CrossTU/CrossTranslationUnit.cpp
===================================================================
--- lib/CrossTU/CrossTranslationUnit.cpp
+++ lib/CrossTU/CrossTranslationUnit.cpp
@@ -149,14 +149,15 @@
 llvm::Expected<const FunctionDecl *>
 CrossTranslationUnitContext::getCrossTUDefinition(const FunctionDecl *FD,
                                                   StringRef CrossTUDir,
-                                                  StringRef IndexName) {
+                                                  StringRef IndexName,
+                                                  bool DisplayCTUProgress) {
   assert(!FD->hasBody() && "FD has a definition in current translation unit!");
   const std::string LookupFnName = getLookupName(FD);
   if (LookupFnName.empty())
     return llvm::make_error<IndexError>(
         index_error_code::failed_to_generate_usr);
   llvm::Expected<ASTUnit *> ASTUnitOrError =
-      loadExternalAST(LookupFnName, CrossTUDir, IndexName);
+      loadExternalAST(LookupFnName, CrossTUDir, IndexName, DisplayCTUProgress);
   if (!ASTUnitOrError)
     return ASTUnitOrError.takeError();
   ASTUnit *Unit = *ASTUnitOrError;
@@ -193,7 +194,8 @@
 }
 
 llvm::Expected<ASTUnit *> CrossTranslationUnitContext::loadExternalAST(
-    StringRef LookupName, StringRef CrossTUDir, StringRef IndexName) {
+    StringRef LookupName, StringRef CrossTUDir, StringRef IndexName,
+    bool DisplayCTUProgress) {
   // FIXME: The current implementation only supports loading functions with
   //        a lookup name from a single translation unit. If multiple
   //        translation units contains functions with the same lookup name an
@@ -233,6 +235,10 @@
           ASTUnit::LoadEverything, Diags, CI.getFileSystemOpts()));
       Unit = LoadedUnit.get();
       FileASTUnitMap[ASTFileName] = std::move(LoadedUnit);
+      if (DisplayCTUProgress) {
+        llvm::errs() << "ANALYZE CTU loaded AST file: "
+                     << ASTFileName << "\n";
+      }
     } else {
       Unit = ASTCacheEntry->second.get();
     }
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -289,6 +289,8 @@
   Opts.NoRetryExhausted = Args.hasArg(OPT_analyzer_disable_retry_exhausted);
   Opts.AnalyzeAll = Args.hasArg(OPT_analyzer_opt_analyze_headers);
   Opts.AnalyzerDisplayProgress = Args.hasArg(OPT_analyzer_display_progress);
+  Opts.AnalyzerDisplayCTUProgress =
+      Args.hasArg(OPT_analyzer_display_ctu_progress);
   Opts.AnalyzeNestedBlocks =
     Args.hasArg(OPT_analyzer_opt_analyze_nested_blocks);
   Opts.AnalyzeSpecificFunction = Args.getLastArgValue(OPT_analyze_function);
Index: lib/StaticAnalyzer/Core/CallEvent.cpp
===================================================================
--- lib/StaticAnalyzer/Core/CallEvent.cpp
+++ lib/StaticAnalyzer/Core/CallEvent.cpp
@@ -560,7 +560,8 @@
   cross_tu::CrossTranslationUnitContext &CTUCtx =
       *Engine->getCrossTranslationUnitContext();
   llvm::Expected<const FunctionDecl *> CTUDeclOrError =
-      CTUCtx.getCrossTUDefinition(FD, Opts.getCTUDir(), Opts.getCTUIndexName());
+      CTUCtx.getCrossTUDefinition(FD, Opts.getCTUDir(), Opts.getCTUIndexName(),
+                                  Opts.AnalyzerDisplayCTUProgress);
 
   if (!CTUDeclOrError) {
     handleAllErrors(CTUDeclOrError.takeError(),
Index: test/Analysis/ctu-main.cpp
===================================================================
--- test/Analysis/ctu-main.cpp
+++ test/Analysis/ctu-main.cpp
@@ -3,6 +3,10 @@
 // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-pch -o %T/ctudir/ctu-chain.cpp.ast %S/Inputs/ctu-chain.cpp
 // RUN: cp %S/Inputs/externalFnMap.txt %T/ctudir/
 // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only -analyze -analyzer-checker=core,debug.ExprInspection -analyzer-config experimental-enable-naive-ctu-analysis=true -analyzer-config ctu-dir=%T/ctudir -verify %s
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only -analyze -analyzer-checker=core,debug.ExprInspection -analyzer-config experimental-enable-naive-ctu-analysis=true -analyzer-config ctu-dir=%T/ctudir -analyzer-display-ctu-progress 2>&1 %s | FileCheck %s
+
+// CHECK: ANALYZE CTU loaded AST file: {{.*}}/ctu-other.cpp
+// CHECK: ANALYZE CTU loaded AST file: {{.*}}/ctu-chain.cpp
 
 #include "ctu-hdr.h"