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
108 lines
3.6 KiB
C++
108 lines
3.6 KiB
C++
//===-- ObjectFileJIT.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_JIT_OBJECTFILEJIT_H
|
|
#define LLDB_SOURCE_PLUGINS_OBJECTFILE_JIT_OBJECTFILEJIT_H
|
|
|
|
#include "lldb/Core/Address.h"
|
|
#include "lldb/Symbol/ObjectFile.h"
|
|
|
|
// This class needs to be hidden as eventually belongs in a plugin that
|
|
// will export the ObjectFile protocol
|
|
class ObjectFileJIT : public lldb_private::ObjectFile {
|
|
public:
|
|
ObjectFileJIT(const lldb::ModuleSP &module_sp,
|
|
const lldb::ObjectFileJITDelegateSP &delegate_sp);
|
|
|
|
~ObjectFileJIT() override;
|
|
|
|
// Static Functions
|
|
static void Initialize();
|
|
|
|
static void Terminate();
|
|
|
|
static llvm::StringRef GetPluginNameStatic() { return "jit"; }
|
|
|
|
static llvm::StringRef GetPluginDescriptionStatic() {
|
|
return "JIT code object file";
|
|
}
|
|
|
|
static lldb_private::ObjectFile *
|
|
CreateInstance(const lldb::ModuleSP &module_sp, lldb::DataBufferSP &data_sp,
|
|
lldb::offset_t data_offset, const lldb_private::FileSpec *file,
|
|
lldb::offset_t file_offset, lldb::offset_t length);
|
|
|
|
static lldb_private::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 lldb_private::FileSpec &file,
|
|
lldb::DataBufferSP &data_sp,
|
|
lldb::offset_t data_offset,
|
|
lldb::offset_t file_offset,
|
|
lldb::offset_t length,
|
|
lldb_private::ModuleSpecList &specs);
|
|
|
|
// 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); }
|
|
|
|
// Member Functions
|
|
bool ParseHeader() override;
|
|
|
|
bool SetLoadAddress(lldb_private::Target &target, lldb::addr_t value,
|
|
bool value_is_offset) override;
|
|
|
|
lldb::ByteOrder GetByteOrder() const override;
|
|
|
|
bool IsExecutable() const override;
|
|
|
|
uint32_t GetAddressByteSize() const override;
|
|
|
|
void ParseSymtab(lldb_private::Symtab &symtab) override;
|
|
|
|
bool IsStripped() override;
|
|
|
|
void CreateSections(lldb_private::SectionList &unified_section_list) override;
|
|
|
|
void Dump(lldb_private::Stream *s) override;
|
|
|
|
lldb_private::ArchSpec GetArchitecture() override;
|
|
|
|
lldb_private::UUID GetUUID() override;
|
|
|
|
uint32_t GetDependentModules(lldb_private::FileSpecList &files) override;
|
|
|
|
size_t ReadSectionData(lldb_private::Section *section,
|
|
lldb::offset_t section_offset, void *dst,
|
|
size_t dst_len) override;
|
|
|
|
size_t
|
|
ReadSectionData(lldb_private::Section *section,
|
|
lldb_private::DataExtractor §ion_data) override;
|
|
|
|
lldb_private::Address GetEntryPointAddress() override;
|
|
|
|
lldb_private::Address GetBaseAddress() override;
|
|
|
|
ObjectFile::Type CalculateType() override;
|
|
|
|
ObjectFile::Strata CalculateStrata() override;
|
|
|
|
// PluginInterface protocol
|
|
llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
|
|
|
|
protected:
|
|
lldb::ObjectFileJITDelegateWP m_delegate_wp;
|
|
};
|
|
|
|
#endif // LLDB_SOURCE_PLUGINS_OBJECTFILE_JIT_OBJECTFILEJIT_H
|