[RemoveDIs] Fix DPLabel crash reported in #82854

Author: OCHyams

llvm/include/llvm/IR/DebugInfo.h

@@ -109,10 +109,8 @@ class DebugInfoFinder {
   void processVariable(const Module &M, const DILocalVariable *DVI);
   /// Process debug info location.
   void processLocation(const Module &M, const DILocation *Loc);
-  // Process a DPValue, much like a DbgVariableIntrinsic.
-  void processDPValue(const Module &M, const DPValue &DPV);
-  /// Dispatch to DbgRecord subclasses handlers.
-  void processDbgRecord(const Module &M, const DbgRecord &DPE);
+  /// Process a DbgRecord (e.g, treat a DPValue like a DbgVariableIntrinsic).
+  void processDbgRecord(const Module &M, const DbgRecord &DR);
 
   /// Process subprogram.
   void processSubprogram(DISubprogram *SP);

llvm/lib/IR/DebugInfo.cpp

@@ -251,13 +251,10 @@ void DebugInfoFinder::processLocation(const Module &M, const DILocation *Loc) {
   processLocation(M, Loc->getInlinedAt());
 }
 
-void DebugInfoFinder::processDPValue(const Module &M, const DPValue &DPV) {
-  processVariable(M, DPV.getVariable());
-  processLocation(M, DPV.getDebugLoc().get());
-}
-
-void DebugInfoFinder::processDbgRecord(const Module &M, const DbgRecord &DPR) {
-  processDPValue(M, cast<DPValue>(DPR));
+void DebugInfoFinder::processDbgRecord(const Module &M, const DbgRecord &DR) {
+  if (const DPValue *DPV = dyn_cast<const DPValue>(&DR))
+    processVariable(M, DPV->getVariable());
+  processLocation(M, DR.getDebugLoc().get());
 }
 
 void DebugInfoFinder::processType(DIType *DT) {