[RemoveDIs][NFC] Introduce DbgRecord base class [1/3] (#78252)

Patch 1 of 3 to add llvm.dbg.label support to the RemoveDIs project. The
patch stack adds a new base class

    -> 1. Add DbgRecord base class for DPValue and the not-yet-added
          DPLabel class.
       2. Add the DPLabel class.
       3. Enable dbg.label conversion and add support to passes.

Patches 1 and 2 are NFC.

In the near future we also will rename DPValue to DbgVariableRecord and
DPLabel to DbgLabelRecord, at which point we'll overhaul the function
names too. The name DPLabel keeps things consistent for now.

1 files changed, 8 insertions, 4 deletions

diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index eaa5cb3..a4fec60 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -240,8 +240,8 @@ void DebugInfoFinder::processInstruction(const Module &M,
   if (auto DbgLoc = I.getDebugLoc())
     processLocation(M, DbgLoc.get());
 
-  for (const DPValue &DPV : I.getDbgValueRange())
-    processDPValue(M, DPV);
+  for (const DbgRecord &DPR : I.getDbgValueRange())
+    processDbgRecord(M, DPR);
 }
 
 void DebugInfoFinder::processLocation(const Module &M, const DILocation *Loc) {
@@ -256,6 +256,10 @@ void DebugInfoFinder::processDPValue(const Module &M, const DPValue &DPV) {
   processLocation(M, DPV.getDebugLoc().get());
 }
 
+void DebugInfoFinder::processDbgRecord(const Module &M, const DbgRecord &DPR) {
+  processDPValue(M, cast<DPValue>(DPR));
+}
+
 void DebugInfoFinder::processType(DIType *DT) {
   if (!addType(DT))
     return;
@@ -1822,7 +1826,7 @@ void at::deleteAll(Function *F) {
   SmallVector<DPValue *, 12> DPToDelete;
   for (BasicBlock &BB : *F) {
     for (Instruction &I : BB) {
-      for (auto &DPV : I.getDbgValueRange())
+      for (DPValue &DPV : DPValue::filter(I.getDbgValueRange()))
         if (DPV.isDbgAssign())
           DPToDelete.push_back(&DPV);
       if (auto *DAI = dyn_cast<DbgAssignIntrinsic>(&I))
@@ -2246,7 +2250,7 @@ bool AssignmentTrackingPass::runOnFunction(Function &F) {
   };
   for (auto &BB : F) {
     for (auto &I : BB) {
-      for (auto &DPV : I.getDbgValueRange()) {
+      for (DPValue &DPV : DPValue::filter(I.getDbgValueRange())) {
         if (DPV.isDbgDeclare())
           ProcessDeclare(&DPV, DPVDeclares);
       }