[llvm] [DebugInfo][RemoveDIs] Extract DPValues in CodeExtractor like dbg.values (PR #73252)

[Orlando Cazalet-Hyams via llvm-commits]

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@@ -1552,8 +1568,41 @@ static void fixupDebugInfoPostExtraction(Function &OldFunc, Function &NewFunc,
   //     point to a variable in the wrong scope.
   SmallDenseMap<DINode *, DINode *> RemappedMetadata;
   SmallVector<Instruction *, 4> DebugIntrinsicsToDelete;
+  SmallVector<DPValue*, 4> DPVsToDelete;
   DenseMap<const MDNode *, MDNode *> Cache;
+
+  auto GetUpdatedDIVariable = [&] (DILocalVariable *OldVar) {
+    DINode *&NewVar = RemappedMetadata[OldVar];
+    if (!NewVar) {
+      DILocalScope *NewScope = DILocalScope::cloneScopeForSubprogram(
+          *OldVar->getScope(), *NewSP, Ctx, Cache);
+      NewVar = DIB.createAutoVariable(
+          NewScope, OldVar->getName(), OldVar->getFile(), OldVar->getLine(),
+          OldVar->getType(), /*AlwaysPreserve=*/false, DINode::FlagZero,
+          OldVar->getAlignInBits());
+    }
+    return cast<DILocalVariable>(NewVar);
+  };
+
+  auto UpdateDPValuesOnInst = [&](Instruction &I) -> void {
+    if (!I.hasDbgValues())
+      return;
+    for (auto &DPV : I.getDbgValueRange()) {
+      // Apply the two updates that dbg.values get: invalid operands, and
+      // variable metadata fixup.
+      if (any_of(DPV.location_ops(), IsInvalidLocation)) {
+        DPVsToDelete.push_back(&DPV);
+        continue;
+      }
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OCHyams wrote:

`// FIXME: Support dbg.assign intrinsics.`


https://github.com/llvm/llvm-project/pull/73252