Files
clang-p2996/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.cpp
Pavel Labath 8395f9cecd [lldb/DWARF] Remove parsing recursion when searching for definition DIEs (#96484)
If ParseStructureLikeDIE (or ParseEnum) encountered a declaration DIE,
it would call FindDefinitionTypeForDIE. This returned a fully formed
type, which it achieved by recursing back into ParseStructureLikeDIE
with the definition DIE.

This obscured the control flow and caused us to repeat some work (e.g.
the UniqueDWARFASTTypeMap lookup), but it mostly worked until we tried
to delay the definition search in #90663. After this patch, the two
ParseStructureLikeDIE calls were no longer recursive, but rather the
second call happened as a part of the CompleteType() call. This opened
the door to inconsistencies, as the second ParseStructureLikeDIE call
was not aware it was called to process a definition die for an existing
type.

To make that possible, this patch removes the recusive type resolution
from this function, and leaves just the "find definition die"
functionality. After finding the definition DIE, we just go back to the
original ParseStructureLikeDIE call, and have it finish the parsing
process with the new DIE.

While this patch is motivated by the work on delaying the definition
searching, I believe it is also useful on its own.
2024-06-25 10:52:11 +02:00

181 lines
6.4 KiB
C++

//===-- SymbolFileDWARFDwo.cpp --------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "SymbolFileDWARFDwo.h"
#include "lldb/Core/Section.h"
#include "lldb/Expression/DWARFExpression.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Utility/LLDBAssert.h"
#include "llvm/Support/Casting.h"
#include "DWARFCompileUnit.h"
#include "DWARFDebugInfo.h"
#include "DWARFUnit.h"
#include <optional>
using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::plugin::dwarf;
char SymbolFileDWARFDwo::ID;
SymbolFileDWARFDwo::SymbolFileDWARFDwo(SymbolFileDWARF &base_symbol_file,
ObjectFileSP objfile, uint32_t id)
: SymbolFileDWARF(objfile, objfile->GetSectionList(
/*update_module_section_list*/ false)),
m_base_symbol_file(base_symbol_file) {
SetFileIndex(id);
// Parsing of the dwarf unit index is not thread-safe, so we need to prime it
// to enable subsequent concurrent lookups.
m_context.GetAsLLVM().getCUIndex();
}
DWARFCompileUnit *SymbolFileDWARFDwo::GetDWOCompileUnitForHash(uint64_t hash) {
if (const llvm::DWARFUnitIndex &index = m_context.GetAsLLVM().getCUIndex()) {
if (const llvm::DWARFUnitIndex::Entry *entry = index.getFromHash(hash)) {
if (auto *unit_contrib = entry->getContribution())
return llvm::dyn_cast_or_null<DWARFCompileUnit>(
DebugInfo().GetUnitAtOffset(DIERef::Section::DebugInfo,
unit_contrib->getOffset()));
}
return nullptr;
}
DWARFCompileUnit *cu = FindSingleCompileUnit();
if (!cu)
return nullptr;
std::optional<uint64_t> dwo_id = cu->GetDWOId();
if (!dwo_id || hash != *dwo_id)
return nullptr;
return cu;
}
DWARFCompileUnit *SymbolFileDWARFDwo::FindSingleCompileUnit() {
DWARFDebugInfo &debug_info = DebugInfo();
// Right now we only support dwo files with one compile unit. If we don't have
// type units, we can just check for the unit count.
if (!debug_info.ContainsTypeUnits() && debug_info.GetNumUnits() == 1)
return llvm::cast<DWARFCompileUnit>(debug_info.GetUnitAtIndex(0));
// Otherwise, we have to run through all units, and find the compile unit that
// way.
DWARFCompileUnit *cu = nullptr;
for (size_t i = 0; i < debug_info.GetNumUnits(); ++i) {
if (auto *candidate =
llvm::dyn_cast<DWARFCompileUnit>(debug_info.GetUnitAtIndex(i))) {
if (cu)
return nullptr; // More that one CU found.
cu = candidate;
}
}
return cu;
}
lldb::offset_t SymbolFileDWARFDwo::GetVendorDWARFOpcodeSize(
const lldb_private::DataExtractor &data, const lldb::offset_t data_offset,
const uint8_t op) const {
return GetBaseSymbolFile().GetVendorDWARFOpcodeSize(data, data_offset, op);
}
uint64_t SymbolFileDWARFDwo::GetDebugInfoSize(bool load_all_debug_info) {
// Directly get debug info from current dwo object file's section list
// instead of asking SymbolFileCommon::GetDebugInfo() which parses from
// owning module which is wrong.
SectionList *section_list =
m_objfile_sp->GetSectionList(/*update_module_section_list=*/false);
if (section_list)
return section_list->GetDebugInfoSize();
return 0;
}
bool SymbolFileDWARFDwo::ParseVendorDWARFOpcode(
uint8_t op, const lldb_private::DataExtractor &opcodes,
lldb::offset_t &offset, std::vector<lldb_private::Value> &stack) const {
return GetBaseSymbolFile().ParseVendorDWARFOpcode(op, opcodes, offset, stack);
}
SymbolFileDWARF::DIEToTypePtr &SymbolFileDWARFDwo::GetDIEToType() {
return GetBaseSymbolFile().GetDIEToType();
}
SymbolFileDWARF::DIEToVariableSP &SymbolFileDWARFDwo::GetDIEToVariable() {
return GetBaseSymbolFile().GetDIEToVariable();
}
SymbolFileDWARF::CompilerTypeToDIE &
SymbolFileDWARFDwo::GetForwardDeclCompilerTypeToDIE() {
return GetBaseSymbolFile().GetForwardDeclCompilerTypeToDIE();
}
void SymbolFileDWARFDwo::GetObjCMethods(
lldb_private::ConstString class_name,
llvm::function_ref<bool(DWARFDIE die)> callback) {
GetBaseSymbolFile().GetObjCMethods(class_name, callback);
}
UniqueDWARFASTTypeMap &SymbolFileDWARFDwo::GetUniqueDWARFASTTypeMap() {
return GetBaseSymbolFile().GetUniqueDWARFASTTypeMap();
}
DWARFDIE SymbolFileDWARFDwo::FindDefinitionDIE(const DWARFDIE &die) {
return GetBaseSymbolFile().FindDefinitionDIE(die);
}
lldb::TypeSP SymbolFileDWARFDwo::FindCompleteObjCDefinitionTypeForDIE(
const DWARFDIE &die, lldb_private::ConstString type_name,
bool must_be_implementation) {
return GetBaseSymbolFile().FindCompleteObjCDefinitionTypeForDIE(
die, type_name, must_be_implementation);
}
llvm::Expected<lldb::TypeSystemSP>
SymbolFileDWARFDwo::GetTypeSystemForLanguage(LanguageType language) {
return GetBaseSymbolFile().GetTypeSystemForLanguage(language);
}
DWARFDIE
SymbolFileDWARFDwo::GetDIE(const DIERef &die_ref) {
if (die_ref.file_index() == GetFileIndex())
return DebugInfo().GetDIE(die_ref.section(), die_ref.die_offset());
return GetBaseSymbolFile().GetDIE(die_ref);
}
void SymbolFileDWARFDwo::FindGlobalVariables(
ConstString name, const CompilerDeclContext &parent_decl_ctx,
uint32_t max_matches, VariableList &variables) {
GetBaseSymbolFile().FindGlobalVariables(name, parent_decl_ctx, max_matches,
variables);
}
bool SymbolFileDWARFDwo::GetDebugInfoIndexWasLoadedFromCache() const {
return GetBaseSymbolFile().GetDebugInfoIndexWasLoadedFromCache();
}
void SymbolFileDWARFDwo::SetDebugInfoIndexWasLoadedFromCache() {
GetBaseSymbolFile().SetDebugInfoIndexWasLoadedFromCache();
}
bool SymbolFileDWARFDwo::GetDebugInfoIndexWasSavedToCache() const {
return GetBaseSymbolFile().GetDebugInfoIndexWasSavedToCache();
}
void SymbolFileDWARFDwo::SetDebugInfoIndexWasSavedToCache() {
GetBaseSymbolFile().SetDebugInfoIndexWasSavedToCache();
}
bool SymbolFileDWARFDwo::GetDebugInfoHadFrameVariableErrors() const {
return GetBaseSymbolFile().GetDebugInfoHadFrameVariableErrors();
}
void SymbolFileDWARFDwo::SetDebugInfoHadFrameVariableErrors() {
return GetBaseSymbolFile().SetDebugInfoHadFrameVariableErrors();
}
SymbolFileDWARF *
SymbolFileDWARFDwo::GetDIERefSymbolFile(const DIERef &die_ref) {
return GetBaseSymbolFile().GetDIERefSymbolFile(die_ref);
}