4 files changed, 51 insertions, 1 deletions

diff --git a/include/llvm/IR/PassManager.h b/include/llvm/IR/PassManager.h
index b85f7f1762..09eb10b846 100644
--- a/include/llvm/IR/PassManager.h
+++ b/include/llvm/IR/PassManager.h
@@ -168,6 +168,9 @@ template <typename IRUnitT, typename AnalysisManagerT> struct PassConcept {
   /// desired. Also that the analysis manager may be null if there is no
   /// analysis manager in the pass pipeline.
   virtual PreservedAnalyses run(IRUnitT IR, AnalysisManagerT *AM) = 0;
+
+  /// \brief Polymorphic method to access the name of a pass.
+  virtual StringRef name() = 0;
 };
 
 /// \brief SFINAE metafunction for computing whether \c PassT has a run method
@@ -208,6 +211,7 @@ struct PassModel<IRUnitT, AnalysisManagerT, PassT,
   virtual PreservedAnalyses run(IRUnitT IR, AnalysisManagerT *AM) {
     return Pass.run(IR, AM);
   }
+  virtual StringRef name() { return PassT::name(); }
   PassT Pass;
 };
 
@@ -221,6 +225,7 @@ struct PassModel<IRUnitT, AnalysisManagerT, PassT,
   virtual PreservedAnalyses run(IRUnitT IR, AnalysisManagerT *AM) {
     return Pass.run(IR);
   }
+  virtual StringRef name() { return PassT::name(); }
   PassT Pass;
 };
 
@@ -403,6 +408,8 @@ public:
     Passes.push_back(new ModulePassModel<ModulePassT>(llvm_move(Pass)));
   }
 
+  static StringRef name() { return "ModulePassManager"; }
+
 private:
   // Pull in the concept type and model template specialized for modules.
   typedef detail::PassConcept<Module *, ModuleAnalysisManager> ModulePassConcept;
@@ -428,6 +435,8 @@ public:
 
   PreservedAnalyses run(Function *F, FunctionAnalysisManager *AM = 0);
 
+  static StringRef name() { return "FunctionPassManager"; }
+
 private:
   // Pull in the concept type and model template specialized for functions.
   typedef detail::PassConcept<Function *, FunctionAnalysisManager>
@@ -808,6 +817,8 @@ public:
     return PA;
   }
 
+  static StringRef name() { return "ModuleToFunctionPassAdaptor"; }
+
 private:
   FunctionPassT Pass;
 };
diff --git a/lib/IR/PassManager.cpp b/lib/IR/PassManager.cpp
index 30b46b01c1..70533fef58 100644
--- a/lib/IR/PassManager.cpp
+++ b/lib/IR/PassManager.cpp
@@ -7,19 +7,36 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/IR/PassManager.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
 
 using namespace llvm;
 
+static cl::opt<bool>
+DebugPM("debug-pass-manager", cl::Hidden,
+        cl::desc("Print pass management debugging information"));
+
 PreservedAnalyses ModulePassManager::run(Module *M, ModuleAnalysisManager *AM) {
   PreservedAnalyses PA = PreservedAnalyses::all();
+
+  if (DebugPM)
+    dbgs() << "Starting module pass manager run.\n";
+
   for (unsigned Idx = 0, Size = Passes.size(); Idx != Size; ++Idx) {
+    if (DebugPM)
+      dbgs() << "Running module pass: " << Passes[Idx]->name() << "\n";
+
     PreservedAnalyses PassPA = Passes[Idx]->run(M, AM);
     if (AM)
       AM->invalidate(M, PassPA);
     PA.intersect(llvm_move(PassPA));
   }
+
+  if (DebugPM)
+    dbgs() << "Finished module pass manager run.\n";
+
   return PA;
 }
 
@@ -61,12 +78,23 @@ void ModuleAnalysisManager::invalidateImpl(Module *M,
 
 PreservedAnalyses FunctionPassManager::run(Function *F, FunctionAnalysisManager *AM) {
   PreservedAnalyses PA = PreservedAnalyses::all();
+
+  if (DebugPM)
+    dbgs() << "Starting function pass manager run.\n";
+
   for (unsigned Idx = 0, Size = Passes.size(); Idx != Size; ++Idx) {
+    if (DebugPM)
+      dbgs() << "Running function pass: " << Passes[Idx]->name() << "\n";
+
     PreservedAnalyses PassPA = Passes[Idx]->run(F, AM);
     if (AM)
       AM->invalidate(F, PassPA);
     PA.intersect(llvm_move(PassPA));
   }
+
+  if (DebugPM)
+    dbgs() << "Finished function pass manager run.\n";
+
   return PA;
 }
 
diff --git a/tools/opt/Passes.cpp b/tools/opt/Passes.cpp
index 49751269df..d58acaf1f6 100644
--- a/tools/opt/Passes.cpp
+++ b/tools/opt/Passes.cpp
@@ -24,6 +24,7 @@ namespace {
   /// \brief No-op module pass which does nothing.
 struct NoOpModulePass {
   PreservedAnalyses run(Module *M) { return PreservedAnalyses::all(); }
+  static StringRef name() { return "NoOpModulePass"; }
 };
 
 } // End anonymous namespace.
diff --git a/unittests/IR/PassManagerTest.cpp b/unittests/IR/PassManagerTest.cpp
index 8db9c67e7d..7b2b46a934 100644
--- a/unittests/IR/PassManagerTest.cpp
+++ b/unittests/IR/PassManagerTest.cpp
@@ -86,6 +86,8 @@ struct TestModulePass {
     return PreservedAnalyses::none();
   }
 
+  static StringRef name() { return "TestModulePass"; }
+
   int &RunCount;
 };
 
@@ -93,6 +95,8 @@ struct TestPreservingModulePass {
   PreservedAnalyses run(Module *M) {
     return PreservedAnalyses::all();
   }
+
+  static StringRef name() { return "TestPreservingModulePass"; }
 };
 
 struct TestMinPreservingModulePass {
@@ -105,6 +109,8 @@ struct TestMinPreservingModulePass {
     PA.preserve<FunctionAnalysisManagerModuleProxy>();
     return PA;
   }
+
+  static StringRef name() { return "TestMinPreservingModulePass"; }
 };
 
 struct TestFunctionPass {
@@ -138,6 +144,8 @@ struct TestFunctionPass {
     return PreservedAnalyses::all();
   }
 
+  static StringRef name() { return "TestFunctionPass"; }
+
   int &RunCount;
   int &AnalyzedInstrCount;
   int &AnalyzedFunctionCount;
@@ -154,6 +162,8 @@ struct TestInvalidationFunctionPass {
                                 : PreservedAnalyses::all();
   }
 
+  static StringRef name() { return "TestInvalidationFunctionPass"; }
+
   StringRef Name;
 };