[llvm] [BOLT][DWARF] Add support for DW_IDX_parent (PR #85285)

[Maksim Panchenko via llvm-commits]

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@@ -464,13 +502,33 @@ void DWARF5AcceleratorTable::writeEntries() {
   for (auto &Bucket : getBuckets()) {
     for (DWARF5AcceleratorTable::HashData *Hash : Bucket) {
       Hash->EntryOffset = EntriesBuffer->size();
-      for (const BOLTDWARF5AccelTableData *Value : Hash->Values) {
+      for (BOLTDWARF5AccelTableData *Value : Hash->Values) {
         writeEntry(*Value);
       }
       support::endian::write(*Entriestream, static_cast<uint8_t>(0),
                              llvm::endianness::little);
     }
   }
+  // Patching parent offsets.
+  for (auto &Bucket : getBuckets()) {
+    for (DWARF5AcceleratorTable::HashData *Hash : Bucket) {
+      for (BOLTDWARF5AccelTableData *Entry : Hash->Values) {
+        std::optional<uint64_t> ParentOffset = Entry->getParentDieOffset();
+        if (!ParentOffset)
+          continue;
+        if (const auto Iter = EntryRelativeOffsets.find(*ParentOffset);
+            Iter != EntryRelativeOffsets.end()) {
+          const uint64_t PatchOffset = Entry->getPatchOffset();
+          uint32_t *Ptr = reinterpret_cast<uint32_t *>(
+              &EntriesBuffer.get()->data()[PatchOffset]);
+          *Ptr = Iter->second;
+        } else {
+          BC.errs() << "Could not find entry with offset " << *ParentOffset
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maksfb wrote:

Is it a warning or an error and when can it get triggered? If the former, change the message to: "BOLT-WARNING: could not find...".




https://github.com/llvm/llvm-project/pull/85285