7e6df41f65
Symbol table parsing has evolved over the years and many plug-ins contained duplicate code in the ObjectFile::GetSymtab() that used to be pure virtual. With this change, the "Symbtab *ObjectFile::GetSymtab()" is no longer virtual and will end up calling a new "void ObjectFile::ParseSymtab(Symtab &symtab)" pure virtual function to actually do the parsing. This helps centralize the code for parsing the symbol table and allows the ObjectFile base class to do all of the common work, like taking the necessary locks and creating the symbol table object itself. Plug-ins now just need to parse when they are asked to parse as the ParseSymtab function will only get called once. This is a retry of the original patch https://reviews.llvm.org/D113965 which was reverted. There was a deadlock in the Manual DWARF indexing code during symbol preloading where the module was asked on the main thread to preload its symbols, and this would in turn cause the DWARF manual indexing to use a thread pool to index all of the compile units, and if there were relocations on the debug information sections, these threads could ask the ObjectFile to load section contents, which could cause a call to ObjectFileELF::RelocateSection() which would ask for the symbol table from the module and it would deadlock. We can't lock the module in ObjectFile::GetSymtab(), so the solution I am using is to use a llvm::once_flag to create the symbol table object once and then lock the Symtab object. Since all APIs on the symbol table use this lock, this will prevent anyone from using the symbol table before it is parsed and finalized and will avoid the deadlock I mentioned. ObjectFileELF::GetSymtab() was never locking the module lock before and would put off creating the symbol table until somewhere inside ObjectFileELF::GetSymtab(). Now we create it one time inside of the ObjectFile::GetSymtab() and immediately lock it which should be safe enough. This avoids the deadlocks and still provides safety. Differential Revision: https://reviews.llvm.org/D114288
105 lines
3.5 KiB
C++
105 lines
3.5 KiB
C++
//===-- ObjectFileBreakpad.h ---------------------------------- -*- C++ -*-===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLDB_SOURCE_PLUGINS_OBJECTFILE_BREAKPAD_OBJECTFILEBREAKPAD_H
|
|
#define LLDB_SOURCE_PLUGINS_OBJECTFILE_BREAKPAD_OBJECTFILEBREAKPAD_H
|
|
|
|
#include "lldb/Symbol/ObjectFile.h"
|
|
#include "lldb/Utility/ArchSpec.h"
|
|
|
|
namespace lldb_private {
|
|
namespace breakpad {
|
|
|
|
class ObjectFileBreakpad : public ObjectFile {
|
|
public:
|
|
// Static Functions
|
|
static void Initialize();
|
|
static void Terminate();
|
|
|
|
static llvm::StringRef GetPluginNameStatic() { return "breakpad"; }
|
|
static const char *GetPluginDescriptionStatic() {
|
|
return "Breakpad object file reader.";
|
|
}
|
|
|
|
static ObjectFile *
|
|
CreateInstance(const lldb::ModuleSP &module_sp, lldb::DataBufferSP &data_sp,
|
|
lldb::offset_t data_offset, const FileSpec *file,
|
|
lldb::offset_t file_offset, lldb::offset_t length);
|
|
|
|
static ObjectFile *CreateMemoryInstance(const lldb::ModuleSP &module_sp,
|
|
lldb::DataBufferSP &data_sp,
|
|
const lldb::ProcessSP &process_sp,
|
|
lldb::addr_t header_addr);
|
|
|
|
static size_t GetModuleSpecifications(const FileSpec &file,
|
|
lldb::DataBufferSP &data_sp,
|
|
lldb::offset_t data_offset,
|
|
lldb::offset_t file_offset,
|
|
lldb::offset_t length,
|
|
ModuleSpecList &specs);
|
|
|
|
// PluginInterface protocol
|
|
llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
|
|
|
|
// LLVM RTTI support
|
|
static char ID;
|
|
bool isA(const void *ClassID) const override {
|
|
return ClassID == &ID || ObjectFile::isA(ClassID);
|
|
}
|
|
static bool classof(const ObjectFile *obj) { return obj->isA(&ID); }
|
|
|
|
// ObjectFile Protocol.
|
|
|
|
bool ParseHeader() override;
|
|
|
|
lldb::ByteOrder GetByteOrder() const override {
|
|
return m_arch.GetByteOrder();
|
|
}
|
|
|
|
bool IsExecutable() const override { return false; }
|
|
|
|
uint32_t GetAddressByteSize() const override {
|
|
return m_arch.GetAddressByteSize();
|
|
}
|
|
|
|
AddressClass GetAddressClass(lldb::addr_t file_addr) override {
|
|
return AddressClass::eInvalid;
|
|
}
|
|
|
|
void ParseSymtab(lldb_private::Symtab &symtab) override;
|
|
|
|
bool IsStripped() override { return false; }
|
|
|
|
void CreateSections(SectionList &unified_section_list) override;
|
|
|
|
void Dump(Stream *s) override {}
|
|
|
|
ArchSpec GetArchitecture() override { return m_arch; }
|
|
|
|
UUID GetUUID() override { return m_uuid; }
|
|
|
|
uint32_t GetDependentModules(FileSpecList &files) override { return 0; }
|
|
|
|
Type CalculateType() override { return eTypeDebugInfo; }
|
|
|
|
Strata CalculateStrata() override { return eStrataUser; }
|
|
|
|
private:
|
|
ArchSpec m_arch;
|
|
UUID m_uuid;
|
|
|
|
ObjectFileBreakpad(const lldb::ModuleSP &module_sp,
|
|
lldb::DataBufferSP &data_sp, lldb::offset_t data_offset,
|
|
const FileSpec *file, lldb::offset_t offset,
|
|
lldb::offset_t length, ArchSpec arch, UUID uuid);
|
|
};
|
|
|
|
} // namespace breakpad
|
|
} // namespace lldb_private
|
|
#endif // LLDB_SOURCE_PLUGINS_OBJECTFILE_BREAKPAD_OBJECTFILEBREAKPAD_H
|