[PATCH] D11236: ScalarEvolution: Make required passes transitive to prevent dangling pointers

[Steve King]

srking created this revision.
srking added a subscriber: llvm-commits.

ScalarEvolution stores long lived raw pointers to objects owned by unique_ptrs in other passes.  In ScalarEvolution, change addRequired() to addRequiredTransitive() to prevent required passes from being freed and thus preven dangling raw pointers.

IMHO, the current design needs a FIXME to eliminate the long lived raw pointers altogether.  Barring that, some way to assert() if the raw pointers becomes dangling would help.

http://reviews.llvm.org/D11236

Files:
  lib/Analysis/ScalarEvolution.cpp

Index: lib/Analysis/ScalarEvolution.cpp
===================================================================
--- lib/Analysis/ScalarEvolution.cpp
+++ lib/Analysis/ScalarEvolution.cpp
@@ -8107,10 +8107,10 @@
 
 void ScalarEvolution::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
-  AU.addRequired<AssumptionCacheTracker>();
+  AU.addRequiredTransitive<AssumptionCacheTracker>();
   AU.addRequiredTransitive<LoopInfoWrapperPass>();
   AU.addRequiredTransitive<DominatorTreeWrapperPass>();
-  AU.addRequired<TargetLibraryInfoWrapperPass>();
+  AU.addRequiredTransitive<TargetLibraryInfoWrapperPass>();
 }
 
 bool ScalarEvolution::hasLoopInvariantBackedgeTakenCount(const Loop *L) {


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