[llvm] [BOLT][DWARF] Add support for transitive DW_AT_name/DW_AT_linkage_name resolution for DW_AT_name/DW_AT_linkage_name. (PR #119493)

[Davide Italiano via llvm-commits]

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@@ -222,134 +222,114 @@ static uint64_t getEntryID(const BOLTDWARF5AccelTableData &Entry) {
   return reinterpret_cast<uint64_t>(&Entry);
 }
 
-std::optional<BOLTDWARF5AccelTableData *>
-DWARF5AcceleratorTable::addAccelTableEntry(
-    DWARFUnit &Unit, const DIE &Die, const std::optional<uint64_t> &DWOID,
-    const uint32_t NumberParentsInChain,
-    std::optional<BOLTDWARF5AccelTableData *> &Parent) {
-  if (Unit.getVersion() < 5 || !NeedToCreate)
-    return std::nullopt;
-  std::string NameToUse = "";
-
-  auto getUnitID = [&](const DWARFUnit &Unit, bool &IsTU,
-                       uint32_t &DieTag) -> uint32_t {
-    IsTU = Unit.isTypeUnit();
-    DieTag = Die.getTag();
-    if (IsTU) {
-      if (DWOID) {
-        const uint64_t TUHash = cast<DWARFTypeUnit>(&Unit)->getTypeHash();
-        auto Iter = TUHashToIndexMap.find(TUHash);
-        assert(Iter != TUHashToIndexMap.end() &&
-               "Could not find TU hash in map");
-        return Iter->second;
-      }
-      return LocalTUList.size() - 1;
+uint32_t DWARF5AcceleratorTable::getUnitID(const DWARFUnit &Unit,
+                                           const std::optional<uint64_t> &DWOID,
+                                           bool &IsTU) {
+  IsTU = Unit.isTypeUnit();
+  if (IsTU) {
+    if (DWOID) {
+      const uint64_t TUHash = cast<DWARFTypeUnit>(&Unit)->getTypeHash();
+      auto Iter = TUHashToIndexMap.find(TUHash);
+      assert(Iter != TUHashToIndexMap.end() && "Could not find TU hash in map");
+      return Iter->second;
     }
-    return CUList.size() - 1;
-  };
+    return LocalTUList.size() - 1;
+  }
+  return CUList.size() - 1;
+}
 
-  if (!canProcess(Unit, Die, NameToUse, false))
+std::optional<std::string> DWARF5AcceleratorTable::getName(
+    DWARFUnit &Unit, const std::optional<uint64_t> &DWOID,
+    const std::string &NameToUse, DIEValue ValName) {
+  if ((!ValName || ValName.getForm() == dwarf::DW_FORM_string) &&
+      NameToUse.empty())
     return std::nullopt;
-
-  // Addes a Unit to either CU, LocalTU or ForeignTU list the first time we
-  // encounter it.
-  // Invoking it here so that we don't add Units that don't have any entries.
-  if (&Unit != CurrentUnit) {
-    CurrentUnit = &Unit;
-    addUnit(Unit, DWOID);
+  std::string Name = "";
+  uint64_t NameIndexOffset = 0;
+  if (NameToUse.empty()) {
+    NameIndexOffset = ValName.getDIEInteger().getValue();
+    if (ValName.getForm() != dwarf::DW_FORM_strp)
+      NameIndexOffset = getNameOffset(BC, Unit, NameIndexOffset);
+    // Counts on strings end with '\0'.
+    Name = std::string(&StrSection.data()[NameIndexOffset]);
+  } else {
+    Name = NameToUse;
   }
-
-  auto getName = [&](DIEValue ValName) -> std::optional<std::string> {
-    if ((!ValName || ValName.getForm() == dwarf::DW_FORM_string) &&
-        NameToUse.empty())
-      return std::nullopt;
-    std::string Name = "";
-    uint64_t NameIndexOffset = 0;
-    if (NameToUse.empty()) {
-      NameIndexOffset = ValName.getDIEInteger().getValue();
-      if (ValName.getForm() != dwarf::DW_FORM_strp)
-        NameIndexOffset = getNameOffset(BC, Unit, NameIndexOffset);
-      // Counts on strings end with '\0'.
-      Name = std::string(&StrSection.data()[NameIndexOffset]);
-    } else {
-      Name = NameToUse;
-    }
-    auto &It = Entries[Name];
-    if (It.Values.empty()) {
-      if (DWOID && NameToUse.empty()) {
-        // For DWO Unit the offset is in the .debug_str.dwo section.
-        // Need to find offset for the name in the .debug_str section.
-        llvm::hash_code Hash = llvm::hash_value(llvm::StringRef(Name));
-        auto ItCache = StrCacheToOffsetMap.find(Hash);
-        if (ItCache == StrCacheToOffsetMap.end())
-          NameIndexOffset = MainBinaryStrWriter.addString(Name);
-        else
-          NameIndexOffset = ItCache->second;
-      }
-      if (!NameToUse.empty())
+  auto &It = Entries[Name];
+  if (It.Values.empty()) {
+    if (DWOID && NameToUse.empty()) {
+      // For DWO Unit the offset is in the .debug_str.dwo section.
+      // Need to find offset for the name in the .debug_str section.
+      llvm::hash_code Hash = llvm::hash_value(llvm::StringRef(Name));
+      auto ItCache = StrCacheToOffsetMap.find(Hash);
+      if (ItCache == StrCacheToOffsetMap.end())
         NameIndexOffset = MainBinaryStrWriter.addString(Name);
-      It.StrOffset = NameIndexOffset;
-      // This the same hash function used in DWARF5AccelTableData.
-      It.HashValue = caseFoldingDjbHash(Name);
+      else
+        NameIndexOffset = ItCache->second;
     }
-    return Name;
-  };
+    if (!NameToUse.empty())
+      NameIndexOffset = MainBinaryStrWriter.addString(Name);
+    It.StrOffset = NameIndexOffset;
+    // This the same hash function used in DWARF5AccelTableData.
----------------
dcci wrote:

"this is"

https://github.com/llvm/llvm-project/pull/119493