[LegacyPassManager] PM does not verifies passes preserved by setPreservesAll()

[pgp01]

Summary

The LegacyPassManager, PMDataManager::verifyPreservedAnalysis() iterates over PreservedSet and calls verifyAnalysis() for each analysis.
In other hand, some passes use setPreservesAll() which setups a flag, but adds nothing to the PreservedSet.

As a result only passes, added by addPreserved<T>(), will be verified.

https://llvm.org/bugs/show_bug.cgi?id=24456

[pgp01]

Kindly reminder

[pgp01]

Kindly reminder

[pgp01]

Hi Chandler,
Could you please take a look at this issue/patch and decide if it could be fixed?
Thanks,
--Pavel.

[pgp01]

Up:)

lib/IR/LegacyPassManager.cpp

 }
 
 /// verifyPreservedAnalysis -- Verify analysis preserved by pass P.
 void PMDataManager::verifyPreservedAnalysis(Pass *P) {
   // Don't do this unless assertions are enabled.
 #ifdef NDEBUG
   return;
 #endif
+
+  const PassInfo *PI = TPM->findAnalysisPassInfo(P->getPassID());
+  if (!PI || PI->isAnalysis()) {
+    return;
+  }
+
   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
 
   // Verify preserved analysis
-  for (AnalysisUsage::VectorType::const_iterator I = PreservedSet.begin(),
-         E = PreservedSet.end(); I != E; ++I) {
-    AnalysisID AID = *I;
-    if (Pass *AP = findAnalysisPass(AID, true)) {
-      TimeRegion PassTimer(getPassTimer(AP));
-      AP->verifyAnalysis();
-    }
-  }
-}
+  for (auto I = AvailableAnalysis.begin(), E = AvailableAnalysis.end();
+            I != E; ++I) {
+    AnalysisID AID = I->first;
+
+    if (!AnUsage->getPreservesAll()) {
+      if (std::find(PreservedSet.begin(), PreservedSet.end(), AID) ==
+          PreservedSet.end()) {
+        continue;
+      }
+    }
+
+    Pass *AP = I->second;
 
 /// Remove Analysis not preserved by Pass P
 void PMDataManager::removeNotPreservedAnalysis(Pass *P) {
   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
   if (AnUsage->getPreservesAll())
     return;
 
   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();