6 files changed, 50 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/CGSCCPassManager.cpp b/llvm/lib/Analysis/CGSCCPassManager.cpp
index b325afb8e7c..6965235326d 100644
--- a/llvm/lib/Analysis/CGSCCPassManager.cpp
+++ b/llvm/lib/Analysis/CGSCCPassManager.cpp
@@ -54,6 +54,11 @@ PassManager<LazyCallGraph::SCC, CGSCCAnalysisManager, LazyCallGraph &,
             CGSCCUpdateResult &>::run(LazyCallGraph::SCC &InitialC,
                                       CGSCCAnalysisManager &AM,
                                       LazyCallGraph &G, CGSCCUpdateResult &UR) {
+  // Request PassInstrumentation from analysis manager, will use it to run
+  // instrumenting callbacks for the passes later.
+  PassInstrumentation PI =
+      AM.getResult<PassInstrumentationAnalysis>(InitialC, G);
+
   PreservedAnalyses PA = PreservedAnalyses::all();
 
   if (DebugLogging)
@@ -67,8 +72,15 @@ PassManager<LazyCallGraph::SCC, CGSCCAnalysisManager, LazyCallGraph &,
     if (DebugLogging)
       dbgs() << "Running pass: " << Pass->name() << " on " << *C << "\n";
 
+    // Check the PassInstrumentation's BeforePass callbacks before running the
+    // pass, skip its execution completely if asked to (callback returns false).
+    if (!PI.runBeforePass(*Pass, *C))
+      continue;
+
     PreservedAnalyses PassPA = Pass->run(*C, AM, G, UR);
 
+    PI.runAfterPass(*Pass, *C);
+
     // Update the SCC if necessary.
     C = UR.UpdatedC ? UR.UpdatedC : C;
 
diff --git a/llvm/lib/FuzzMutate/IRMutator.cpp b/llvm/lib/FuzzMutate/IRMutator.cpp
index 2dc7dfb880a..40e402cdade 100644
--- a/llvm/lib/FuzzMutate/IRMutator.cpp
+++ b/llvm/lib/FuzzMutate/IRMutator.cpp
@@ -73,6 +73,7 @@ static void eliminateDeadCode(Function &F) {
   FPM.addPass(DCEPass());
   FunctionAnalysisManager FAM;
   FAM.registerPass([&] { return TargetLibraryAnalysis(); });
+  FAM.registerPass([&] { return PassInstrumentationAnalysis(); });
   FPM.run(F, FAM);
 }
 
diff --git a/llvm/lib/IR/CMakeLists.txt b/llvm/lib/IR/CMakeLists.txt
index a194b840e0e..2586f987289 100644
--- a/llvm/lib/IR/CMakeLists.txt
+++ b/llvm/lib/IR/CMakeLists.txt
@@ -42,6 +42,7 @@ add_llvm_library(LLVMCore
   Operator.cpp
   OptBisect.cpp
   Pass.cpp
+  PassInstrumentation.cpp
   PassManager.cpp
   PassRegistry.cpp
   PassTimingInfo.cpp
diff --git a/llvm/lib/IR/PassInstrumentation.cpp b/llvm/lib/IR/PassInstrumentation.cpp
new file mode 100644
index 00000000000..5aa2bc6d895
--- /dev/null
+++ b/llvm/lib/IR/PassInstrumentation.cpp
@@ -0,0 +1,22 @@
+//===- PassInstrumentation.cpp - Pass Instrumentation interface -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// This file provides the implementation of PassInstrumentation class.
+///
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/PassInstrumentation.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+AnalysisKey PassInstrumentationAnalysis::Key;
+
+} // namespace llvm
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
index 5748c0d9f8a..b070b0ed303 100644
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -26,6 +26,7 @@ MODULE_ANALYSIS("no-op-module", NoOpModuleAnalysis())
 MODULE_ANALYSIS("profile-summary", ProfileSummaryAnalysis())
 MODULE_ANALYSIS("targetlibinfo", TargetLibraryAnalysis())
 MODULE_ANALYSIS("verify", VerifierAnalysis())
+MODULE_ANALYSIS("pass-instrumentation", PassInstrumentationAnalysis(PIC))
 
 #ifndef MODULE_ALIAS_ANALYSIS
 #define MODULE_ALIAS_ANALYSIS(NAME, CREATE_PASS)                               \
@@ -84,6 +85,7 @@ MODULE_PASS("verify", VerifierPass())
 #endif
 CGSCC_ANALYSIS("no-op-cgscc", NoOpCGSCCAnalysis())
 CGSCC_ANALYSIS("fam-proxy", FunctionAnalysisManagerCGSCCProxy())
+CGSCC_ANALYSIS("pass-instrumentation", PassInstrumentationAnalysis(PIC))
 #undef CGSCC_ANALYSIS
 
 #ifndef CGSCC_PASS
@@ -121,6 +123,7 @@ FUNCTION_ANALYSIS("targetlibinfo", TargetLibraryAnalysis())
 FUNCTION_ANALYSIS("targetir",
                   TM ? TM->getTargetIRAnalysis() : TargetIRAnalysis())
 FUNCTION_ANALYSIS("verify", VerifierAnalysis())
+FUNCTION_ANALYSIS("pass-instrumentation", PassInstrumentationAnalysis(PIC))
 
 #ifndef FUNCTION_ALIAS_ANALYSIS
 #define FUNCTION_ALIAS_ANALYSIS(NAME, CREATE_PASS)                             \
@@ -226,6 +229,7 @@ FUNCTION_PASS("view-cfg-only", CFGOnlyViewerPass())
 LOOP_ANALYSIS("no-op-loop", NoOpLoopAnalysis())
 LOOP_ANALYSIS("access-info", LoopAccessAnalysis())
 LOOP_ANALYSIS("ivusers", IVUsersAnalysis())
+LOOP_ANALYSIS("pass-instrumentation", PassInstrumentationAnalysis(PIC))
 #undef LOOP_ANALYSIS
 
 #ifndef LOOP_PASS
diff --git a/llvm/lib/Transforms/Scalar/LoopPassManager.cpp b/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
index 10f6fcdcfdb..6759bd2537c 100644
--- a/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
@@ -30,12 +30,22 @@ PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
   if (DebugLogging)
     dbgs() << "Starting Loop pass manager run.\n";
 
+  // Request PassInstrumentation from analysis manager, will use it to run
+  // instrumenting callbacks for the passes later.
+  PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(L, AR);
   for (auto &Pass : Passes) {
     if (DebugLogging)
       dbgs() << "Running pass: " << Pass->name() << " on " << L;
 
+    // Check the PassInstrumentation's BeforePass callbacks before running the
+    // pass, skip its execution completely if asked to (callback returns false).
+    if (!PI.runBeforePass<Loop>(*Pass, L))
+      continue;
+
     PreservedAnalyses PassPA = Pass->run(L, AM, AR, U);
 
+    PI.runAfterPass<Loop>(*Pass, L);
+
     // If the loop was deleted, abort the run and return to the outer walk.
     if (U.skipCurrentLoop()) {
       PA.intersect(std::move(PassPA));