diff --git a/lldb/include/lldb/Symbol/SymbolFile.h b/lldb/include/lldb/Symbol/SymbolFile.h
--- a/lldb/include/lldb/Symbol/SymbolFile.h
+++ b/lldb/include/lldb/Symbol/SymbolFile.h
@@ -25,6 +25,7 @@
 #include "lldb/Utility/XcodeSDK.h"
 #include "lldb/lldb-private.h"
 #include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/SmallSet.h"
 #include "llvm/Support/Errc.h"
 
 #include <mutex>
@@ -146,6 +147,17 @@
   virtual lldb::LanguageType ParseLanguage(CompileUnit &comp_unit) = 0;
   /// Return the Xcode SDK comp_unit was compiled against.
   virtual XcodeSDK ParseXcodeSDK(CompileUnit &comp_unit) { return {}; }
+
+  /// This function exists because SymbolFileDWARFDebugMap may extra compile
+  /// units which aren't exposed as "real" compile units. In every other
+  /// case this function should behave identically as ParseLanguage.
+  virtual llvm::SmallSet<lldb::LanguageType, 4>
+  ParseAllLanguages(CompileUnit &comp_unit) {
+    llvm::SmallSet<lldb::LanguageType, 4> langs;
+    langs.insert(ParseLanguage(comp_unit));
+    return langs;
+  }
+
   virtual size_t ParseFunctions(CompileUnit &comp_unit) = 0;
   virtual bool ParseLineTable(CompileUnit &comp_unit) = 0;
   virtual bool ParseDebugMacros(CompileUnit &comp_unit) = 0;
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h
@@ -62,6 +62,8 @@
   ParseLanguage(lldb_private::CompileUnit &comp_unit) override;
   lldb_private::XcodeSDK
   ParseXcodeSDK(lldb_private::CompileUnit &comp_unit) override;
+  llvm::SmallSet<lldb::LanguageType, 4>
+  ParseAllLanguages(lldb_private::CompileUnit &comp_unit) override;
   size_t ParseFunctions(lldb_private::CompileUnit &comp_unit) override;
   bool ParseLineTable(lldb_private::CompileUnit &comp_unit) override;
   bool ParseDebugMacros(lldb_private::CompileUnit &comp_unit) override;
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp
@@ -683,6 +683,17 @@
   return {};
 }
 
+llvm::SmallSet<lldb::LanguageType, 4>
+SymbolFileDWARFDebugMap::ParseAllLanguages(
+    lldb_private::CompileUnit &comp_unit) {
+  llvm::SmallSet<lldb::LanguageType, 4> langs;
+  auto *info = GetCompUnitInfo(comp_unit);
+  for (auto &comp_unit : info->compile_units_sps) {
+    langs.insert(comp_unit->GetLanguage());
+  }
+  return langs;
+}
+
 size_t SymbolFileDWARFDebugMap::ParseFunctions(CompileUnit &comp_unit) {
   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);