From e33e47695300decc0516f91e37573c57634467cc Mon Sep 17 00:00:00 2001
From: Douglas Chen <dougpuob@gmail.com>
Date: Sun, 19 Dec 2021 09:56:34 +0800
Subject: [PATCH] Register plugin with registerPipelineStartEPCallback()
 function.

---
 HelloWorld/HelloWorld.cpp | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/HelloWorld/HelloWorld.cpp b/HelloWorld/HelloWorld.cpp
index 82ced8d..e1d877b 100644
--- a/HelloWorld/HelloWorld.cpp
+++ b/HelloWorld/HelloWorld.cpp
@@ -37,6 +37,9 @@ namespace {
 void visitor(Function &F) {
     errs() << "(llvm-tutor) Hello from: "<< F.getName() << "\n";
     errs() << "(llvm-tutor)   number of arguments: " << F.arg_size() << "\n";
+    for (const Instruction &I : F.getEntryBlock()) {
+        errs() << "(llvm-tutor)    Opcode : " <<  I.getOpcodeName() << "\n";
+      }
 }
 
 // New PM implementation
@@ -47,6 +50,10 @@ struct HelloWorld : PassInfoMixin<HelloWorld> {
     visitor(F);
     return PreservedAnalyses::all();
   }
+
+  static bool isRequired() {
+    return true;
+  }
 };
 
 // Legacy PM implementation
@@ -68,16 +75,14 @@ struct LegacyHelloWorld : public FunctionPass {
 llvm::PassPluginLibraryInfo getHelloWorldPluginInfo() {
   return {LLVM_PLUGIN_API_VERSION, "HelloWorld", LLVM_VERSION_STRING,
           [](PassBuilder &PB) {
-            PB.registerPipelineParsingCallback(
-                [](StringRef Name, FunctionPassManager &FPM,
-                   ArrayRef<PassBuilder::PipelineElement>) {
-                  if (Name == "hello-world") {
-                    FPM.addPass(HelloWorld());
-                    return true;
-                  }
-                  return false;
-                });
-          }};
+            errs() << "registerPipelineStartEPCallback" << "\n";
+            PB.registerPipelineStartEPCallback(
+              [](ModulePassManager &MPM, OptimizationLevel Level) {
+                 FunctionPassManager FPM;                 
+                 FPM.addPass(HelloWorld());
+                 MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
+			});
+         }};
 }
 
 // This is the core interface for pass plugins. It guarantees that 'opt' will
-- 
2.25.1