[llvm] [DwarfDump] Add new set of line-table-related statistics to llvm-dwarfdump (PR #93289)

[Felipe de Azevedo Piovezan via llvm-commits]

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@@ -882,8 +902,58 @@ bool dwarfdump::collectStatsForObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
         CrossCUReferencesToBeResolved.push_back(
             DIELocation(CUDie.getDwarfUnit(), CrossCUReferencingDIEOffset));
     }
+    const auto *LineTable = DICtx.getLineTableForUnit(CU.get());
+    std::optional<uint64_t> LastFileIdxOpt;
+    if (LineTable)
+      LastFileIdxOpt = LineTable->getLastValidFileIndex();
+    if (LastFileIdxOpt) {
+      // Each CU has its own file index; in order to track unique line entries
+      // across CUs, we therefore need to map each CU file index to a global
+      // file index, which we store here.
+      DenseMap<uint64_t, uint16_t> CUFileMapping;
+      std::string File;
+      for (uint64_t FileIdx = 0; FileIdx <= *LastFileIdxOpt; ++FileIdx) {
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felipepiovezan wrote:

Aren't dwarf 4 indices 1-based and 0-based in dwarf 5?

https://github.com/llvm/llvm-project/pull/93289