[PATCH] D50717: [SimplifyCFG] Fix BasicBlock use-after-free

[Chijun Sima via Phabricator via llvm-commits]

NutshellySima created this revision.
NutshellySima added reviewers: kuhar, dmgreen, davide, trentxintong.
Herald added a subscriber: llvm-commits.

Fix use-after-free in SimplifyCFG pass.


Repository:
  rL LLVM

https://reviews.llvm.org/D50717

Files:
  lib/Transforms/Utils/SimplifyCFG.cpp


Index: lib/Transforms/Utils/SimplifyCFG.cpp
===================================================================
--- lib/Transforms/Utils/SimplifyCFG.cpp
+++ lib/Transforms/Utils/SimplifyCFG.cpp
@@ -3861,9 +3861,9 @@
   }
 
   // The landingpad is now unreachable.  Zap it.
-  BB->eraseFromParent();
   if (LoopHeaders)
     LoopHeaders->erase(BB);
+  BB->eraseFromParent();
   return true;
 }
 
@@ -4083,9 +4083,9 @@
     // If we eliminated all predecessors of the block, delete the block now.
     if (pred_empty(BB)) {
       // We know there are no successors, so just nuke the block.
-      BB->eraseFromParent();
       if (LoopHeaders)
         LoopHeaders->erase(BB);
+      BB->eraseFromParent();
     }
 
     return true;
@@ -4245,9 +4245,9 @@
   // If this block is now dead, remove it.
   if (pred_empty(BB) && BB != &BB->getParent()->getEntryBlock()) {
     // We know there are no successors, so just nuke the block.
-    BB->eraseFromParent();
     if (LoopHeaders)
       LoopHeaders->erase(BB);
+    BB->eraseFromParent();
     return true;
   }
 


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