[nfc] [lldb] DWZ 01/17: Remove DWARFDIE from DeclContextToDIEMap m_decl_ctx_to_die

[jankratochvil]

Summary

Replace DWARFDIE by std::pair<SymbolFileDWARF *, DIERef>. Currently it has the same size but after D96236 it would needlessly increase from 16 bytes to 24 bytes affecting performance. This replacement should have no real performance disadvantage.

My question about upstreaming of this patchset.

[jankratochvil]

I will be no longer involved with this patchset.

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

 protected:
   /// Protected typedefs and members.
   /// @{
   class DelayedAddObjCClassProperty;
   typedef std::vector<DelayedAddObjCClassProperty> DelayedPropertyList;
 
   typedef llvm::DenseMap<const DWARFDebugInfoEntry *, clang::DeclContext *>
       DIEToDeclContextMap;
-  typedef std::multimap<const clang::DeclContext *, const DWARFDIE>
-      DeclContextToDIEMap;
+  typedef std::multimap<const clang::DeclContext *,
+                        std::pair<SymbolFileDWARF *, DIERef>>
+      DeclContextToFileDIERefMap;
   typedef llvm::DenseMap<const DWARFDebugInfoEntry *,
                          lldb_private::OptionalClangModuleID>
       DIEToModuleMap;
   typedef llvm::DenseMap<const DWARFDebugInfoEntry *, clang::Decl *>
       DIEToDeclMap;
 
   lldb_private::TypeSystemClang &m_ast;
   DIEToDeclMap m_die_to_decl;
   DIEToDeclContextMap m_die_to_decl_ctx;
-  DeclContextToDIEMap m_decl_ctx_to_die;
+  DeclContextToFileDIERefMap m_decl_ctx_to_filedieref;
   DIEToModuleMap m_die_to_module;
   std::unique_ptr<lldb_private::ClangASTImporter> m_clang_ast_importer_up;
   /// @}
 
   clang::DeclContext *GetDeclContextForBlock(const DWARFDIE &die);
 
   clang::BlockDecl *ResolveBlockDIE(const DWARFDIE &die);
 

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

 #define DEBUG_PRINTF(fmt, ...) printf(fmt, __VA_ARGS__)
 #else
 #define DEBUG_PRINTF(fmt, ...)
 #endif
 
 using namespace lldb;
 using namespace lldb_private;
 DWARFASTParserClang::DWARFASTParserClang(TypeSystemClang &ast)
-    : m_ast(ast), m_die_to_decl_ctx(), m_decl_ctx_to_die() {}
+    : m_ast(ast), m_die_to_decl_ctx(), m_decl_ctx_to_filedieref() {}
 
 DWARFASTParserClang::~DWARFASTParserClang() = default;
 
 static AccessType DW_ACCESS_to_AccessType(uint32_t dwarf_accessibility) {
   switch (dwarf_accessibility) {
   case DW_ACCESS_public:
     return eAccessPublic;
   case DW_ACCESS_private:
bool DWARFASTParserClang::CompleteTypeFromDWARF(const DWARFDIE &die,
 
   return false;
 }
 
 void DWARFASTParserClang::EnsureAllDIEsInDeclContextHaveBeenParsed(
     lldb_private::CompilerDeclContext decl_context) {
   auto opaque_decl_ctx =
       (clang::DeclContext *)decl_context.GetOpaqueDeclContext();
-  for (auto it = m_decl_ctx_to_die.find(opaque_decl_ctx);
-       it != m_decl_ctx_to_die.end() && it->first == opaque_decl_ctx;
-       it = m_decl_ctx_to_die.erase(it))
-    for (DWARFDIE decl : it->second.children())
+  for (auto it = m_decl_ctx_to_filedieref.find(opaque_decl_ctx);
+       it != m_decl_ctx_to_filedieref.end() && it->first == opaque_decl_ctx;
+       it = m_decl_ctx_to_filedieref.erase(it)) {
+    // We need to store also SymbolFileDWARF * as we cannot assume
+    // m_ast.GetSymbolFile() is actually a SymbolFileDWARF, it can be
+    // a SymbolFileDWARFDebugMap for Apple binaries.
+    std::pair<SymbolFileDWARF *, DIERef> declpair = it->second;
+    DWARFDIE die = declpair.first->GetDIE(declpair.second);
+    for (DWARFDIE decl : die.children())
       GetClangDeclForDIE(decl);
   }
+}
 
 CompilerDecl DWARFASTParserClang::GetDeclForUIDFromDWARF(const DWARFDIE &die) {
   clang::Decl *clang_decl = GetClangDeclForDIE(die);
   if (clang_decl != nullptr)
     return m_ast.GetCompilerDecl(clang_decl);
   return CompilerDecl();
 }
 
if (pos != m_die_to_decl_ctx.end())
       return pos->second;
   }
   return nullptr;
 }
 
 void DWARFASTParserClang::LinkDeclContextToDIE(clang::DeclContext *decl_ctx,
                                                const DWARFDIE &die) {
   m_die_to_decl_ctx[die.GetDIE()] = decl_ctx;
+  SymbolFileDWARF *sym_file = &die.GetCU()->GetSymbolFileDWARF();
+  DIERef ref = *die.GetDIERef();
   // There can be many DIEs for a single decl context
-  // m_decl_ctx_to_die[decl_ctx].insert(die.GetDIE());
-  m_decl_ctx_to_die.insert(std::make_pair(decl_ctx, die));
+  // m_decl_ctx_to_filedieref[decl_ctx].insert(...);
+  m_decl_ctx_to_filedieref.insert(
+      std::make_pair(decl_ctx, std::make_pair(sym_file, ref)));
 }
 
 bool DWARFASTParserClang::CopyUniqueClassMethodTypes(
     const DWARFDIE &src_class_die, const DWARFDIE &dst_class_die,
     lldb_private::Type *class_type, std::vector<DWARFDIE> &failures) {
   if (!class_type || !src_class_die || !dst_class_die)
     return false;
   if (src_class_die.Tag() != dst_class_die.Tag())

lldb/unittests/SymbolFile/DWARF/DWARFASTParserClangTests.cpp

 
 class DWARFASTParserClangStub : public DWARFASTParserClang {
 public:
   using DWARFASTParserClang::DWARFASTParserClang;
   using DWARFASTParserClang::LinkDeclContextToDIE;
 
   std::vector<const clang::DeclContext *> GetDeclContextToDIEMapKeys() {
     std::vector<const clang::DeclContext *> keys;
-    for (const auto &it : m_decl_ctx_to_die)
+    for (const auto &it : m_decl_ctx_to_filedieref)
       keys.push_back(it.first);
     return keys;
   }
 };
 } // namespace
 
 // If your implementation needs to dereference the dummy pointers we are
 // defining here, causing this test to fail, feel free to delete it.