[llvm] [BOLT] Fix updating DW_AT_stmt_list for DWARF5 TUs. (PR #79374)

[Maksim Panchenko via llvm-commits]

================
@@ -1393,41 +1393,60 @@ void DWARFRewriter::updateLineTableOffsets(const MCAsmLayout &Layout) {
   // ones.
   std::unordered_map<uint64_t, uint64_t> DebugLineOffsetMap;
 
-  auto GetStatementListValue = [](DWARFUnit *Unit) {
-    std::optional<DWARFFormValue> StmtList =
-        Unit->getUnitDIE().find(dwarf::DW_AT_stmt_list);
+  auto GetStatementListValue =
+      [](const DWARFDie &DIE) -> std::optional<uint64_t> {
+    std::optional<DWARFFormValue> StmtList = DIE.find(dwarf::DW_AT_stmt_list);
+    if (!StmtList)
+      return std::nullopt;
     std::optional<uint64_t> Offset = dwarf::toSectionOffset(StmtList);
     assert(Offset && "Was not able to retrieve value of DW_AT_stmt_list.");
     return *Offset;
   };
 
-  for (const std::unique_ptr<DWARFUnit> &CU : BC.DwCtx->compile_units()) {
+  SmallVector<DWARFUnit *, 1> TUs;
+  for (const std::unique_ptr<DWARFUnit> &CU : BC.DwCtx->info_section_units()) {
+    if (CU->isTypeUnit()) {
+      TUs.push_back(CU.get());
+      continue;
+    }
     const unsigned CUID = CU->getOffset();
     MCSymbol *Label = BC.getDwarfLineTable(CUID).getLabel();
     if (!Label)
       continue;
 
-    std::optional<AttrInfo> AttrVal =
-        findAttributeInfo(CU.get()->getUnitDIE(), dwarf::DW_AT_stmt_list);
-    if (!AttrVal)
+    std::optional<uint64_t> StmtOffset =
+        GetStatementListValue(CU.get()->getUnitDIE());
+    if (!StmtOffset)
       continue;
 
     const uint64_t LineTableOffset = Layout.getSymbolOffset(*Label);
-    DebugLineOffsetMap[GetStatementListValue(CU.get())] = LineTableOffset;
+    DebugLineOffsetMap[*StmtOffset] = LineTableOffset;
     assert(DbgInfoSection && ".debug_info section must exist");
     LineTablePatchMap[CU.get()] = LineTableOffset;
   }
 
-  for (const std::unique_ptr<DWARFUnit> &TU : BC.DwCtx->types_section_units()) {
-    DWARFUnit *Unit = TU.get();
-    std::optional<AttrInfo> AttrVal =
-        findAttributeInfo(TU.get()->getUnitDIE(), dwarf::DW_AT_stmt_list);
-    if (!AttrVal)
+  for (const std::unique_ptr<DWARFUnit> &TU : BC.DwCtx->types_section_units())
+    TUs.push_back(TU.get());
+
+  for (DWARFUnit *TU : TUs) {
+    std::optional<uint64_t> StmtOffset =
+        GetStatementListValue(TU->getUnitDIE());
+    if (!StmtOffset)
+      continue;
+    auto Iter = DebugLineOffsetMap.find(*StmtOffset);
+    if (Iter == DebugLineOffsetMap.end()) {
+      // Implementation depends on TU sharing DW_AT_stmt_list with a CU.
+      // Only case that it hasn't been true was for manually modified assembly
+      // file. Adding this warning in case assumption is false.
+      errs()
+          << "BOLT-WARNING: [internal-dwarf-error]: A TU at offset: "
----------------
maksfb wrote:

"... at offset: 0x"

https://github.com/llvm/llvm-project/pull/79374