[llvm][DebugInfo] Emit DW_AT_lanugage_name

Author: Michael137

llvm/include/llvm/BinaryFormat/Dwarf.def

@@ -424,6 +424,8 @@ HANDLE_DW_AT(0x89, export_symbols, 5, DWARF)
 HANDLE_DW_AT(0x8a, deleted, 5, DWARF)
 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)
 
 // Vendor extensions:
 HANDLE_DW_AT(0x806, GHS_namespace_alias, 0, GHS)

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -1039,8 +1039,12 @@ void DwarfDebug::finishUnitAttributes(const DICompileUnit *DIUnit,
   } else
     NewCU.addString(Die, dwarf::DW_AT_producer, Producer);
 
-  NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
-                DIUnit->getSourceLanguage().getUnversionedName());
+  if (auto Lang = DIUnit->getSourceLanguage(); Lang.hasVersionedName())
+    NewCU.addUInt(Die, dwarf::DW_AT_language_name, dwarf::DW_FORM_data2,
+                  Lang.getName());
+  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();