[llvm][DebugInfo] DW_AT_language_version

Author: Michael137

llvm/include/llvm/BinaryFormat/Dwarf.def

@@ -426,6 +426,7 @@ HANDLE_DW_AT(0x8b, defaulted, 5, DWARF)
 HANDLE_DW_AT(0x8c, loclists_base, 5, DWARF)
 // New in Dwarf v6:
 HANDLE_DW_AT(0x90, language_name, 6, DWARF)
+HANDLE_DW_AT(0x91, language_version, 6, DWARF)
 
 // Vendor extensions:
 HANDLE_DW_AT(0x806, GHS_namespace_alias, 0, GHS)

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -1039,12 +1039,18 @@ void DwarfDebug::finishUnitAttributes(const DICompileUnit *DIUnit,
   } else
     NewCU.addString(Die, dwarf::DW_AT_producer, Producer);
 
-  if (auto Lang = DIUnit->getSourceLanguage(); Lang.hasVersionedName())
+  if (auto Lang = DIUnit->getSourceLanguage(); Lang.hasVersionedName()) {
     NewCU.addUInt(Die, dwarf::DW_AT_language_name, dwarf::DW_FORM_data2,
                   Lang.getName());
-  else
+
+    if (uint32_t LangVersion = Lang.getVersion();
+        LangVersion != 0)
+      NewCU.addUInt(Die, dwarf::DW_AT_language_version, /*Form=*/std::nullopt,
+                    LangVersion);
+  } else {
     NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
                   Lang.getName());
+  }
 
   NewCU.addString(Die, dwarf::DW_AT_name, FN);
   StringRef SysRoot = DIUnit->getSysRoot();