[llvm] [LLVM[NFC] Refactor to allow debug_names entries to conatain DIE offset (PR #69399)

[David Blaikie via llvm-commits]

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@@ -252,20 +252,27 @@ class DWARF5AccelTableData : public AccelTableData {
 public:
   static uint32_t hash(StringRef Name) { return caseFoldingDjbHash(Name); }
 
-  DWARF5AccelTableData(const DIE &Die) : Die(Die) {}
+  DWARF5AccelTableData(const DIE &Die, const DwarfCompileUnit &CU);
 
 #ifndef NDEBUG
   void print(raw_ostream &OS) const override;
 #endif
 
-  const DIE &getDie() const { return Die; }
-  uint64_t getDieOffset() const { return Die.getOffset(); }
-  unsigned getDieTag() const { return Die.getTag(); }
+  uint64_t getDieOffset() const {
+    if (const DIE *const *TDie = std::get_if<const DIE *>(&OffsetVal))
+      return (*TDie)->getOffset();
+    return std::get<uint64_t>(OffsetVal);
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dwblaikie wrote:

I think it'd be a somewhat simpler conceptual model if all uses of the DIE offsets in the accelerator tables came in the offset mode, after the DIE mode, if possible. Like after the DIE tree is finalized, we could finalize the accelerator in a similar way?

Like just after the `computeSizeAndOffsets` call in `DwarfDebug::finalizeModuleInfo()` we could do something similar to the accelerator tables? (call some function then take the sizes and offsets so computed, and bake them in/discard the DIE references)

https://github.com/llvm/llvm-project/pull/69399