Index: flang/lib/Frontend/CMakeLists.txt
===================================================================
--- flang/lib/Frontend/CMakeLists.txt
+++ flang/lib/Frontend/CMakeLists.txt
@@ -42,6 +42,7 @@
   LINK_COMPONENTS
   Passes
   Analysis
+  Extensions
   IRReader
   Option
   Support
Index: flang/lib/Frontend/FrontendActions.cpp
===================================================================
--- flang/lib/Frontend/FrontendActions.cpp
+++ flang/lib/Frontend/FrontendActions.cpp
@@ -48,6 +48,7 @@
 #include "llvm/IRReader/IRReader.h"
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Passes/PassBuilder.h"
+#include "llvm/Passes/PassPlugin.h"
 #include "llvm/Passes/StandardInstrumentations.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/SourceMgr.h"
@@ -56,6 +57,11 @@
 
 using namespace Fortran::frontend;
 
+// Declare plugin extension function declarations.
+#define HANDLE_EXTENSION(Ext)                                                  \
+  llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
+#include "llvm/Support/Extension.def"
+
 //===----------------------------------------------------------------------===//
 // Custom BeginSourceFileAction
 //===----------------------------------------------------------------------===//
@@ -691,6 +697,11 @@
   si.registerCallbacks(pic, &fam);
   llvm::PassBuilder pb(tm.get(), pto, pgoOpt, &pic);
 
+  // Register static plugin extensions.
+#define HANDLE_EXTENSION(Ext)                                                  \
+  get##Ext##PluginInfo().RegisterPassBuilderCallbacks(pb);
+#include "llvm/Support/Extension.def"
+
   // Register all the basic analyses with the managers.
   pb.registerModuleAnalyses(mam);
   pb.registerCGSCCAnalyses(cgam);