Index: clang/include/clang/Frontend/CompilerInstance.h
===================================================================
--- clang/include/clang/Frontend/CompilerInstance.h
+++ clang/include/clang/Frontend/CompilerInstance.h
@@ -219,6 +219,8 @@
   // of the context or else not CompilerInstance specific.
   bool ExecuteAction(FrontendAction &Act);
 
+  void LoadRequestedPlugins();
+
   /// }
   /// @name Compiler Invocation and Options
   /// {
Index: clang/lib/Frontend/CompilerInstance.cpp
===================================================================
--- clang/lib/Frontend/CompilerInstance.cpp
+++ clang/lib/Frontend/CompilerInstance.cpp
@@ -23,6 +23,7 @@
 #include "clang/Frontend/FrontendAction.h"
 #include "clang/Frontend/FrontendActions.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/FrontendPluginRegistry.h"
 #include "clang/Frontend/LogDiagnosticPrinter.h"
 #include "clang/Frontend/SerializedDiagnosticPrinter.h"
 #include "clang/Frontend/TextDiagnosticPrinter.h"
@@ -1029,6 +1030,27 @@
   return !getDiagnostics().getClient()->getNumErrors();
 }
 
+void CompilerInstance::LoadRequestedPlugins() {
+  // Load any requested plugins.
+  for (const std::string &Path : getFrontendOpts().Plugins) {
+    std::string Error;
+    if (llvm::sys::DynamicLibrary::LoadLibraryPermanently(Path.c_str(), &Error))
+      getDiagnostics().Report(diag::err_fe_unable_to_load_plugin)
+          << Path << Error;
+  }
+
+  // Check if any of the loaded plugins replaces the main AST action
+  for (const FrontendPluginRegistry::entry &Plugin :
+       FrontendPluginRegistry::entries()) {
+    std::unique_ptr<PluginASTAction> P(Plugin.instantiate());
+    if (P->getActionType() == PluginASTAction::ReplaceAction) {
+      getFrontendOpts().ProgramAction = clang::frontend::PluginAction;
+      getFrontendOpts().ActionName = Plugin.getName().str();
+      break;
+    }
+  }
+}
+
 /// Determine the appropriate source input kind based on language
 /// options.
 static Language getLanguageFromOptions(const LangOptions &LangOpts) {
Index: clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
===================================================================
--- clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -203,24 +203,7 @@
     return true;
   }
 
-  // Load any requested plugins.
-  for (const std::string &Path : Clang->getFrontendOpts().Plugins) {
-    std::string Error;
-    if (llvm::sys::DynamicLibrary::LoadLibraryPermanently(Path.c_str(), &Error))
-      Clang->getDiagnostics().Report(diag::err_fe_unable_to_load_plugin)
-        << Path << Error;
-  }
-
-  // Check if any of the loaded plugins replaces the main AST action
-  for (const FrontendPluginRegistry::entry &Plugin :
-       FrontendPluginRegistry::entries()) {
-    std::unique_ptr<PluginASTAction> P(Plugin.instantiate());
-    if (P->getActionType() == PluginASTAction::ReplaceAction) {
-      Clang->getFrontendOpts().ProgramAction = clang::frontend::PluginAction;
-      Clang->getFrontendOpts().ActionName = Plugin.getName().str();
-      break;
-    }
-  }
+  Clang->LoadRequestedPlugins();
 
   // Honor -mllvm.
   //
Index: clang/lib/Interpreter/IncrementalParser.cpp
===================================================================
--- clang/lib/Interpreter/IncrementalParser.cpp
+++ clang/lib/Interpreter/IncrementalParser.cpp
@@ -65,6 +65,8 @@
           case frontend::ParseSyntaxOnly:
             Act = CreateFrontendAction(CI);
             break;
+          case frontend::PluginAction:
+            LLVM_FALLTHROUGH;
           case frontend::EmitAssembly:
             LLVM_FALLTHROUGH;
           case frontend::EmitObj:
Index: clang/tools/clang-repl/CMakeLists.txt
===================================================================
--- clang/tools/clang-repl/CMakeLists.txt
+++ clang/tools/clang-repl/CMakeLists.txt
@@ -16,3 +16,8 @@
   clangInterpreter
   clangTooling
   )
+
+# Support plugins.
+if(CLANG_PLUGIN_SUPPORT)
+  export_executable_symbols_for_plugins(clang-repl)
+endif()
Index: clang/tools/clang-repl/ClangRepl.cpp
===================================================================
--- clang/tools/clang-repl/ClangRepl.cpp
+++ clang/tools/clang-repl/ClangRepl.cpp
@@ -80,6 +80,9 @@
   llvm::install_fatal_error_handler(LLVMErrorHandler,
                                     static_cast<void *>(&CI->getDiagnostics()));
 
+  // Load any requested plugins.
+  CI->LoadRequestedPlugins();
+
   auto Interp = ExitOnErr(clang::Interpreter::create(std::move(CI)));
   for (const std::string &input : OptInputs) {
     if (auto Err = Interp->ParseAndExecute(input))