replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

DWARF: Avoid storing DIERefs in long-lived containers 

Summary:
A user_id_t carries the same information as a DIERef, but it takes up
less space.

Furthermore, DIERef::operator<'s implementation is very
questionable, as it does not take the cu_offset and section fields into
account. Using just the die offset was correct in the days when all
debug info lived in a single section, but since we started supporting
DWO debug info, this was no longer true. The comparison operator could
be fixed, but it seems like using the user_id_t for these purposes is a
better idea overall.

I think this did not cause any bugs, because the only place the
comparison operator was used is in m_function_scope_qualified_name_map,
and this one is local to a dwo file, but I am not 100% sure of that.

Reviewers: clayborg, JDevlieghere

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D63322

llvm-svn: 363528
This commit is contained in:
Pavel Labath 2019-06-17 07:32:56 +00:00
parent ee62c40eae
commit a71ce4f1e8
4 changed files with 31 additions and 50 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
lldb/source/Plugins/SymbolFile/DWARF/DIERef.h
View File

@ -25,10 +25,6 @@ struct DIERef {
explicit DIERef(const DWARFFormValue &form_value);
bool operator<(const DIERef &ref) const {
return die_offset < ref.die_offset;
}
explicit operator bool() const {
return cu_offset != DW_INVALID_OFFSET || die_offset != DW_INVALID_OFFSET;
}

2
lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
View File

@ -998,7 +998,7 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
clang_type.GetOpaqueQualType();
dwarf->GetForwardDeclClangTypeToDie()
[ClangUtil::RemoveFastQualifiers(clang_type).GetOpaqueQualType()] =
die.GetDIERef();
die.GetID();
m_ast.SetHasExternalStorage(clang_type.GetOpaqueQualType(), true);
}
}

68
lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
View File

@ -2327,15 +2327,9 @@ void SymbolFileDWARF::GetMangledNamesForFunction(
dwo->GetMangledNamesForFunction(scope_qualified_name, mangled_names);
}
NameToOffsetMap::iterator iter =
m_function_scope_qualified_name_map.find(scope_qualified_name);
if (iter == m_function_scope_qualified_name_map.end())
return;
DIERefSetSP set_sp = (*iter).second;
std::set<DIERef>::iterator set_iter;
for (set_iter = set_sp->begin(); set_iter != set_sp->end(); set_iter++) {
DWARFDIE die = DebugInfo()->GetDIE(*set_iter);
for (lldb::user_id_t uid :
m_function_scope_qualified_name_map.lookup(scope_qualified_name)) {
DWARFDIE die = GetDIE(uid);
mangled_names.push_back(ConstString(die.GetMangledName()));
}
}
@ -2952,42 +2946,32 @@ TypeSP SymbolFileDWARF::FindDefinitionTypeForDWARFDeclContext(
TypeSP SymbolFileDWARF::ParseType(const SymbolContext &sc, const DWARFDIE &die,
bool *type_is_new_ptr) {
TypeSP type_sp;
if (!die)
return {};
if (die) {
TypeSystem *type_system =
GetTypeSystemForLanguage(die.GetCU()->GetLanguageType());
TypeSystem *type_system =
GetTypeSystemForLanguage(die.GetCU()->GetLanguageType());
if (!type_system)
return {};
if (type_system) {
DWARFASTParser *dwarf_ast = type_system->GetDWARFParser();
if (dwarf_ast) {
Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
type_sp = dwarf_ast->ParseTypeFromDWARF(sc, die, log, type_is_new_ptr);
if (type_sp) {
TypeList *type_list = GetTypeList();
if (type_list)
type_list->Insert(type_sp);
DWARFASTParser *dwarf_ast = type_system->GetDWARFParser();
if (!dwarf_ast)
return {};
if (die.Tag() == DW_TAG_subprogram) {
DIERef die_ref = die.GetDIERef();
std::string scope_qualified_name(GetDeclContextForUID(die.GetID())
.GetScopeQualifiedName()
.AsCString(""));
if (scope_qualified_name.size()) {
NameToOffsetMap::iterator iter =
m_function_scope_qualified_name_map.find(
scope_qualified_name);
if (iter != m_function_scope_qualified_name_map.end())
(*iter).second->insert(die_ref);
else {
DIERefSetSP new_set(new std::set<DIERef>);
new_set->insert(die_ref);
m_function_scope_qualified_name_map.emplace(
std::make_pair(scope_qualified_name, new_set));
}
}
}
}
Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
TypeSP type_sp = dwarf_ast->ParseTypeFromDWARF(sc, die, log, type_is_new_ptr);
if (type_sp) {
TypeList *type_list = GetTypeList();
if (type_list)
type_list->Insert(type_sp);
if (die.Tag() == DW_TAG_subprogram) {
std::string scope_qualified_name(GetDeclContextForUID(die.GetID())
.GetScopeQualifiedName()
.AsCString(""));
if (scope_qualified_name.size()) {
m_function_scope_qualified_name_map[scope_qualified_name].insert(
die.GetID());
}
}
}

7
lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
View File

@ -309,7 +309,8 @@ protected:
typedef llvm::DenseMap<const DWARFDebugInfoEntry *,
lldb::opaque_compiler_type_t>
DIEToClangType;
typedef llvm::DenseMap<lldb::opaque_compiler_type_t, DIERef> ClangTypeToDIE;
typedef llvm::DenseMap<lldb::opaque_compiler_type_t, lldb::user_id_t>
ClangTypeToDIE;
struct DWARFDataSegment {
llvm::once_flag m_flag;
@ -471,8 +472,8 @@ protected:
bool m_fetched_external_modules : 1;
lldb_private::LazyBool m_supports_DW_AT_APPLE_objc_complete_type;
typedef std::shared_ptr<std::set<DIERef>> DIERefSetSP;
typedef std::unordered_map<std::string, DIERefSetSP> NameToOffsetMap;
typedef std::set<lldb::user_id_t> DIERefSet;
typedef llvm::StringMap<DIERefSet> NameToOffsetMap;
NameToOffsetMap m_function_scope_qualified_name_map;
std::unique_ptr<DWARFDebugRangesBase> m_ranges;
std::unique_ptr<DWARFDebugRangesBase> m_rnglists;