[lldb] Introduce SymbolFile::ParseAllLanguages

[augusto2112]

Summary

SymbolFile::ParseAllLanguages allows collecting the languages of the
extra compile units a SymbolFileDWARFDebugMap may have, which can't
be accessed otherwise. For every other symbol file type, it should
behave exactly the same as ParseLanguage.

rdar://97610458

[aprantl]

You could add a test similar to lldb/unittests/SymbolFile/DWARF/XcodeSDKModuleTests.cpp

lldb/include/lldb/Symbol/SymbolFile.h

154

I would increase the set size to 4. It's quite common to have C, C++, and ObjC in the same module.

lldb/include/lldb/Symbol/SymbolFile.h

 #include "lldb/Symbol/SourceModule.h"
 #include "lldb/Symbol/Type.h"
 #include "lldb/Symbol/TypeList.h"
 #include "lldb/Symbol/TypeSystem.h"
 #include "lldb/Target/Statistics.h"
 #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>
 #include <optional>
 
 #if defined(LLDB_CONFIGURATION_DEBUG)
 #define ASSERT_MODULE_LOCK(expr) (expr->AssertModuleLock())
 #else
public:
   virtual uint32_t GetNumCompileUnits() = 0;
   virtual lldb::CompUnitSP GetCompileUnitAtIndex(uint32_t idx) = 0;
 
   virtual Symtab *GetSymtab() = 0;
 
   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;
 
   /// Apply a lambda to each external lldb::Module referenced by this
   /// \p comp_unit. Recursively also descends into the referenced external
   /// modules of any encountered compilation unit.
   ///

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h

public:
   uint32_t CalculateAbilities() override;
   void InitializeObject() override;
 
   // Compile Unit function calls
   lldb::LanguageType
   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;
 
   bool ForEachExternalModule(
       lldb_private::CompileUnit &, llvm::DenseSet<lldb_private::SymbolFile *> &,
       llvm::function_ref<bool(lldb_private::Module &)>) override;
 

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp

 XcodeSDK SymbolFileDWARFDebugMap::ParseXcodeSDK(CompileUnit &comp_unit) {
   std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   SymbolFileDWARF *oso_dwarf = GetSymbolFile(comp_unit);
   if (oso_dwarf)
     return oso_dwarf->ParseXcodeSDK(comp_unit);
   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);
   if (oso_dwarf)
     return oso_dwarf->ParseFunctions(comp_unit);
   return 0;
 }