Introduce DebugInfoProbe. This is used to monitor how llvm optimizer is treating debugging information.

It generates output that lools like

8 times line number info lost by Scalar Replacement of Aggregates (SSAUp) 
1 times line number info lost by Simplify well-known library calls 
12 times variable info lost by Jump Threading



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127381 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 22 insertions, 1 deletions

diff --git a/lib/VMCore/PassManager.cpp b/lib/VMCore/PassManager.cpp
index cd170df..ca4455a 100644
--- a/lib/VMCore/PassManager.cpp
+++ b/lib/VMCore/PassManager.cpp
@@ -14,6 +14,7 @@
 
 #include "llvm/PassManagers.h"
 #include "llvm/PassManager.h"
+#include "llvm/DebugInfoProbe.h"
 #include "llvm/Assembly/PrintModulePass.h"
 #include "llvm/Assembly/Writer.h"
 #include "llvm/Support/CommandLine.h"
@@ -25,6 +26,7 @@
 #include "llvm/Support/PassNameParser.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/Mutex.h"
+#include "llvm/ADT/StringMap.h"
 #include <algorithm>
 #include <cstdio>
 #include <map>
@@ -442,6 +444,20 @@ char PassManagerImpl::ID = 0;
 namespace {
 
 //===----------------------------------------------------------------------===//
+// DebugInfoProbe
+
+static DebugInfoProbeInfo *TheDebugProbe;
+static void createDebugInfoProbe() {
+  if (TheDebugProbe) return;
+      
+  // Constructed the first time this is called. This guarantees that the 
+  // object will be constructed, if -enable-debug-info-probe is set, 
+  // before static globals, thus it will be destroyed before them.
+  static ManagedStatic<DebugInfoProbeInfo> DIP;
+  TheDebugProbe = &*DIP;
+}
+
+//===----------------------------------------------------------------------===//
 /// TimingInfo Class - This class is used to calculate information about the
 /// amount of time each pass takes to execute.  This only happens when
 /// -time-passes is enabled on the command line.
@@ -1430,6 +1446,7 @@ void FunctionPassManagerImpl::releaseMemoryOnTheFly() {
 bool FunctionPassManagerImpl::run(Function &F) {
   bool Changed = false;
   TimingInfo::createTheTimeInfo();
+  createDebugInfoProbe();
 
   initializeAllAnalysisInfo();
   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
@@ -1477,13 +1494,16 @@ bool FPPassManager::runOnFunction(Function &F) {
     dumpRequiredSet(FP);
 
     initializeAnalysisImpl(FP);
-
+    if (TheDebugProbe)
+      TheDebugProbe->initialize(FP, F);
     {
       PassManagerPrettyStackEntry X(FP, F);
       TimeRegion PassTimer(getPassTimer(FP));
 
       LocalChanged |= FP->runOnFunction(F);
     }
+    if (TheDebugProbe)
+      TheDebugProbe->finalize(FP, F);
 
     Changed |= LocalChanged;
     if (LocalChanged)
@@ -1631,6 +1651,7 @@ Pass* MPPassManager::getOnTheFlyPass(Pass *MP, AnalysisID PI, Function &F){
 bool PassManagerImpl::run(Module &M) {
   bool Changed = false;
   TimingInfo::createTheTimeInfo();
+  createDebugInfoProbe();
 
   dumpArguments();
   dumpPasses();