[llvm] [DebugInfo][RemoveDIs] Support cloning and remapping DPValues (PR #72546)

[Jeremy Morse via llvm-commits]

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@@ -535,6 +537,37 @@ Value *Mapper::mapValue(const Value *V) {
   return getVM()[V] = ConstantPointerNull::get(cast<PointerType>(NewTy));
 }
 
+void Mapper::remapDPValue(DPValue &V) {
+  // Remap variables and DILocations.
+  auto *MappedVar = mapMetadata(V.getVariable());
+  auto *MappedDILoc = mapMetadata(V.getDebugLoc());
+  V.setVariable(cast<DILocalVariable>(MappedVar));
+  V.setDebugLoc(DebugLoc(cast<DILocation>(MappedDILoc)));
+
+  // Find Value operands and remap those.
+  SmallVector<Value *, 4> Vals, NewVals;
+  for (Value *Val: V.location_ops())
+    Vals.push_back(Val);
+  for (Value *Val : Vals)
+    NewVals.push_back(mapValue(Val));
+
+  // If there are no changes to the Value operands, finished.
+  if (Vals == NewVals)
+    return;
+
+  bool IgnoreMissingLocals = Flags & RF_IgnoreMissingLocals;
+
+  // Otherwise, do some replacement.
+  if (!IgnoreMissingLocals &&
+      llvm::any_of(NewVals, [&](Value *V) { return V == nullptr;})) {
+    V.setKillLocation();
+  } else {
+    for (unsigned int I = 0; I < Vals.size(); ++I)
+      if (NewVals[I] || !IgnoreMissingLocals)
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jmorse wrote:

Good catch; I've just removed the check and added a comment, asserting something that's guaranteed three lines above seems like overkill.

https://github.com/llvm/llvm-project/pull/72546