A plug-in interface definition class for dynamic loaders. More...

#include "lldb/Target/DynamicLoader.h"

Inheritance diagram for lldb_private::DynamicLoader:

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Collaboration diagram for lldb_private::DynamicLoader:

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Public Member Functions
	DynamicLoader (Process *process)
	Construct with a process. More...

	~DynamicLoader () override
	Destructor. More...

virtual void	DidAttach ()=0
	Called after attaching a process. More...

virtual void	DidLaunch ()=0
	Called after launching a process. More...

virtual bool	ProcessDidExec ()
	Helper function that can be used to detect when a process has called exec and is now a new and different process. More...

bool	GetStopWhenImagesChange () const
	Get whether the process should stop when images change. More...

void	SetStopWhenImagesChange (bool stop)
	Set whether the process should stop when images change. More...

virtual lldb::ThreadPlanSP	GetStepThroughTrampolinePlan (Thread &thread, bool stop_others)=0
	Provides a plan to step through the dynamic loader trampoline for the current state of thread. More...

virtual size_t	FindEquivalentSymbols (Symbol *original_symbol, ModuleList &module_list, SymbolContextList &equivalent_symbols)
	Some dynamic loaders provide features where there are a group of symbols "equivalent to" a given symbol one of which will be chosen when the symbol is bound. More...

virtual Status	CanLoadImage ()=0
	Ask if it is ok to try and load or unload an shared library (image). More...

virtual bool	AlwaysRelyOnEHUnwindInfo (SymbolContext &sym_ctx)
	Ask if the eh_frame information for the given SymbolContext should be relied on even when it's the first frame in a stack unwind. More...

virtual lldb::addr_t	GetThreadLocalData (const lldb::ModuleSP module, const lldb::ThreadSP thread, lldb::addr_t tls_file_addr)
	Retrieves the per-module TLS block for a given thread. More...

virtual lldb::ModuleSP	LoadModuleAtAddress (const lldb_private::FileSpec &file, lldb::addr_t link_map_addr, lldb::addr_t base_addr, bool base_addr_is_offset)
	Locates or creates a module given by `file` and updates/loads the resulting module at the virtual base address `base_addr`. More...

virtual bool	GetSharedCacheInformation (lldb::addr_t &base_address, UUID &uuid, LazyBool &using_shared_cache, LazyBool &private_shared_cache)
	Get information about the shared cache for a process, if possible. More...

Public Member Functions inherited from lldb_private::PluginInterface
virtual	~PluginInterface ()

virtual ConstString	GetPluginName ()=0

virtual uint32_t	GetPluginVersion ()=0

Static Public Member Functions
static DynamicLoader *	FindPlugin (Process process, const char plugin_name)
	Find a dynamic loader plugin for a given process. More...

Protected Member Functions
lldb::ModuleSP	GetTargetExecutable ()
	Checks to see if the target module has changed, updates the target accordingly and returns the target executable module. More...

virtual void	UpdateLoadedSections (lldb::ModuleSP module, lldb::addr_t link_map_addr, lldb::addr_t base_addr, bool base_addr_is_offset)
	Updates the load address of every allocatable section in `module`. More...

void	UpdateLoadedSectionsCommon (lldb::ModuleSP module, lldb::addr_t base_addr, bool base_addr_is_offset)

virtual void	UnloadSections (const lldb::ModuleSP module)
	Removes the loaded sections from the target in `module`. More...

void	UnloadSectionsCommon (const lldb::ModuleSP module)

const lldb_private::SectionList *	GetSectionListFromModule (const lldb::ModuleSP module) const

int64_t	ReadUnsignedIntWithSizeInBytes (lldb::addr_t addr, int size_in_bytes)

lldb::addr_t	ReadPointer (lldb::addr_t addr)

void	LoadOperatingSystemPlugin (bool flush)

Protected Attributes
Process *	m_process
	The process that this dynamic loader plug-in is tracking. More...

Detailed Description

A plug-in interface definition class for dynamic loaders.

Dynamic loader plug-ins track image (shared library) loading and unloading. The class is initialized given a live process that is halted at its entry point or just after attaching.

Dynamic loader plug-ins can track the process by registering callbacks using the: Process::RegisterNotificationCallbacks (const Notifications&) function.

Breakpoints can also be set in the process which can register functions that get called using: Process::BreakpointSetCallback (lldb::user_id_t, BreakpointHitCallback, void *). These breakpoint callbacks return a boolean value that indicates if the process should continue or halt and should return the global setting for this using: DynamicLoader::StopWhenImagesChange() const.

Definition at line 64 of file DynamicLoader.h.

Constructor & Destructor Documentation

◆ DynamicLoader()

DynamicLoader::DynamicLoader ( Process * process )

Construct with a process.

Definition at line 61 of file DynamicLoader.cpp.

References ~DynamicLoader().

◆ ~DynamicLoader()

DynamicLoader::~DynamicLoader ( )

overridedefault

Destructor.

The destructor is virtual since this class is designed to be inherited from by the plug-in instance.

Referenced by DynamicLoader().

Member Function Documentation

◆ AlwaysRelyOnEHUnwindInfo()

virtual bool lldb_private::DynamicLoader::AlwaysRelyOnEHUnwindInfo ( SymbolContext & sym_ctx )

inlinevirtual

Ask if the eh_frame information for the given SymbolContext should be relied on even when it's the first frame in a stack unwind.

The CFI instructions from the eh_frame section are normally only valid at call sites – places where a program could throw an exception and need to unwind out. But some Modules may be known to the system as having reliable eh_frame information at all call sites. This would be the case if the Module's contents are largely hand-written assembly with hand-written eh_frame information. Normally when unwinding from a function at the beginning of a stack unwind lldb will examine the assembly instructions to understand how the stack frame is set up and where saved registers are stored. But with hand-written assembly this is not reliable enough – we need to consult those function's hand-written eh_frame information.

Returns: True if the symbol context should use eh_frame instructions unconditionally when unwinding from this frame. Else false, the normal lldb unwind behavior of only using eh_frame when the function appears in the middle of the stack.

Reimplemented in DynamicLoaderPOSIXDYLD, and lldb_private::DynamicLoaderDarwin.

Definition at line 203 of file DynamicLoader.h.

◆ CanLoadImage()

virtual Status lldb_private::DynamicLoader::CanLoadImage ( )

pure virtual

Ask if it is ok to try and load or unload an shared library (image).

The dynamic loader often knows when it would be ok to try and load or unload a shared library. This function call allows the dynamic loader plug-ins to check any current dyld state to make sure it is an ok time to load a shared library.

Returns: true if it is currently ok to try and load a shared library into the process, false otherwise.

Implemented in DynamicLoaderMacOSXDYLD, DynamicLoaderDarwinKernel, DynamicLoaderMacOS, DynamicLoaderPOSIXDYLD, DynamicLoaderStatic, DynamicLoaderHexagonDYLD, and lldb_private::DynamicLoaderWindowsDYLD.

Referenced by PlatformPOSIX::EvaluateLibdlExpression(), and FindEquivalentSymbols().

◆ DidAttach()

virtual void lldb_private::DynamicLoader::DidAttach ( )

pure virtual

Called after attaching a process.

Allow DynamicLoader plug-ins to execute some code after attaching to a process.

Implemented in DynamicLoaderDarwinKernel, DynamicLoaderPOSIXDYLD, DynamicLoaderStatic, lldb_private::DynamicLoaderDarwin, DynamicLoaderHexagonDYLD, and lldb_private::DynamicLoaderWindowsDYLD.

Referenced by lldb_private::Process::CompleteAttach(), and lldb_private::Process::LoadCore().

◆ DidLaunch()

virtual void lldb_private::DynamicLoader::DidLaunch ( )

pure virtual

Called after launching a process.

Allow DynamicLoader plug-ins to execute some code after the process has stopped for the first time on launch.

Implemented in DynamicLoaderDarwinKernel, DynamicLoaderPOSIXDYLD, DynamicLoaderStatic, lldb_private::DynamicLoaderDarwin, DynamicLoaderHexagonDYLD, and lldb_private::DynamicLoaderWindowsDYLD.

Referenced by lldb_private::Process::Launch().

◆ FindEquivalentSymbols()

virtual size_t lldb_private::DynamicLoader::FindEquivalentSymbols	(	Symbol *	original_symbol,
		ModuleList &	module_list,
		SymbolContextList &	equivalent_symbols
	)

inlinevirtual

Some dynamic loaders provide features where there are a group of symbols "equivalent to" a given symbol one of which will be chosen when the symbol is bound.

If you want to set a breakpoint on one of these symbols, you really need to set it on all the equivalent symbols.

Parameters

[in]	original_symbol	The symbol for which we are finding equivalences.
[in]	module_list	The set of modules in which to search.
[out]	equivalent_symbols	The equivalent symbol list - any equivalent symbols found are appended to this list.

Returns: Number of equivalent symbols found.

Reimplemented in lldb_private::DynamicLoaderDarwin.

Definition at line 165 of file DynamicLoader.h.

References CanLoadImage().

◆ FindPlugin()

DynamicLoader * DynamicLoader::FindPlugin	(	Process *	process,
		const char *	plugin_name
	)

static

Find a dynamic loader plugin for a given process.

Scans the installed DynamicLoader plug-ins and tries to find an instance that can be used to track image changes in process.

Parameters

[in]	process	The process for which to try and locate a dynamic loader plug-in instance.
[in]	plugin_name	An optional name of a specific dynamic loader plug-in that should be used. If NULL, pick the best plug-in.

Definition at line 32 of file DynamicLoader.cpp.

Referenced by lldb_private::ProcessWindows::GetDynamicLoader(), lldb_private::process_gdb_remote::ProcessGDBRemote::GetDynamicLoader(), and lldb_private::Process::GetDynamicLoader().

◆ GetSectionListFromModule()

const SectionList * DynamicLoader::GetSectionListFromModule ( const lldb::ModuleSP module ) const

protected

Definition at line 141 of file DynamicLoader.cpp.

References lldb_private::ObjectFile::GetSectionList().

Referenced by GetSharedCacheInformation(), and UnloadSectionsCommon().

◆ GetSharedCacheInformation()

virtual bool lldb_private::DynamicLoader::GetSharedCacheInformation	(	lldb::addr_t &	base_address,
		UUID &	uuid,
		LazyBool &	using_shared_cache,
		LazyBool &	private_shared_cache
	)

inlinevirtual

Get information about the shared cache for a process, if possible.

On some systems (e.g. Darwin based systems), a set of libraries that are common to most processes may be put in a single region of memory and mapped into every process, this is called the shared cache, as a performance optimization.

Many targets will not have the concept of a shared cache.

Depending on how the DynamicLoader gathers information about the shared cache, it may be able to only return basic information - like the UUID of the cache - or it may be able to return additional information about the cache.

Parameters

[out]	base_address	The base address (load address) of the shared cache. LLDB_INVALID_ADDRESS if it cannot be determined.
[out]	uuid	The UUID of the shared cache, if it can be determined. If the UUID cannot be fetched, IsValid() will be false.
[out]	using_shared_cache	If this process is using a shared cache. If unknown, eLazyBoolCalculate is returned.
[out]	private_shared_cache	A LazyBool indicating whether this process is using a private shared cache. If this information cannot be fetched, eLazyBoolCalculate.

Returns: Returns false if this DynamicLoader cannot gather information about the shared cache / has no concept of a shared cache.

Reimplemented in DynamicLoaderMacOSXDYLD, and DynamicLoaderMacOS.

Definition at line 266 of file DynamicLoader.h.

References lldb_private::UUID::Clear(), lldb_private::eLazyBoolCalculate, GetSectionListFromModule(), GetTargetExecutable(), LLDB_INVALID_ADDRESS, LoadOperatingSystemPlugin(), ReadPointer(), ReadUnsignedIntWithSizeInBytes(), UnloadSections(), UnloadSectionsCommon(), UpdateLoadedSections(), and UpdateLoadedSectionsCommon().

Referenced by ObjectFileMachO::GetProcessSharedCacheUUID().

◆ GetStepThroughTrampolinePlan()

virtual lldb::ThreadPlanSP lldb_private::DynamicLoader::GetStepThroughTrampolinePlan	(	Thread &	thread,
		bool	stop_others
	)

pure virtual

Provides a plan to step through the dynamic loader trampoline for the current state of thread.

Parameters

[in] stop_others Whether the plan should be set to stop other threads.

Returns: A pointer to the plan (caller owned) or NULL if we are not at such a trampoline.

Implemented in DynamicLoaderDarwinKernel, DynamicLoaderPOSIXDYLD, DynamicLoaderStatic, lldb_private::DynamicLoaderDarwin, DynamicLoaderHexagonDYLD, and lldb_private::DynamicLoaderWindowsDYLD.

Referenced by lldb_private::ThreadPlanStepThrough::LookForPlanToStepThroughFromCurrentPC(), and ProcessDidExec().

◆ GetStopWhenImagesChange()

bool DynamicLoader::GetStopWhenImagesChange ( ) const

Get whether the process should stop when images change.

When images (executables and shared libraries) get loaded or unloaded, often debug sessions will want to try and resolve or unresolve breakpoints that are set in these images. Any breakpoints set by DynamicLoader plug-in instances should return this value to ensure consistent debug session behaviour.

Returns: Returns true if the process should stop when images change, false if the process should resume.

Definition at line 68 of file DynamicLoader.cpp.

References lldb_private::ProcessProperties::GetStopOnSharedLibraryEvents(), and m_process.

Referenced by DynamicLoaderDarwinKernel::BreakpointHit(), DynamicLoaderMacOS::NotifyBreakpointHit(), DynamicLoaderMacOSXDYLD::NotifyBreakpointHit(), ProcessDidExec(), DynamicLoaderHexagonDYLD::RendezvousBreakpointHit(), and DynamicLoaderPOSIXDYLD::RendezvousBreakpointHit().

◆ GetTargetExecutable()

ModuleSP DynamicLoader::GetTargetExecutable ( )

protected

Checks to see if the target module has changed, updates the target accordingly and returns the target executable module.

Definition at line 76 of file DynamicLoader.cpp.

References lldb_private::eLoadDependentsNo, lldb_private::Target::GetExecutableModule(), lldb_private::Target::GetExecutableModulePointer(), lldb_private::Target::GetOrCreateModule(), lldb_private::Process::GetTarget(), lldb_private::FileSystem::Instance(), m_process, and lldb_private::Target::SetExecutableModule().

Referenced by lldb_private::DynamicLoaderWindowsDYLD::DidAttach(), DynamicLoaderPOSIXDYLD::DidAttach(), lldb_private::DynamicLoaderWindowsDYLD::DidLaunch(), DynamicLoaderPOSIXDYLD::DidLaunch(), GetSharedCacheInformation(), and DynamicLoaderPOSIXDYLD::LoadAllCurrentModules().

◆ GetThreadLocalData()

virtual lldb::addr_t lldb_private::DynamicLoader::GetThreadLocalData	(	const lldb::ModuleSP	module,
		const lldb::ThreadSP	thread,
		lldb::addr_t	tls_file_addr
	)

inlinevirtual

Retrieves the per-module TLS block for a given thread.

Parameters

[in]	module	The module to query TLS data for.
[in]	thread	The specific thread to query TLS data for.

Returns: If the given thread has TLS data allocated for the module, the address of the TLS block. Otherwise LLDB_INVALID_ADDRESS is returned.

Reimplemented in DynamicLoaderPOSIXDYLD, lldb_private::DynamicLoaderDarwin, and DynamicLoaderHexagonDYLD.

Definition at line 219 of file DynamicLoader.h.

References LLDB_INVALID_ADDRESS, and LoadModuleAtAddress().

Referenced by lldb_private::Thread::GetThreadLocalData().

◆ LoadModuleAtAddress()

ModuleSP DynamicLoader::LoadModuleAtAddress	(	const lldb_private::FileSpec &	file,
		lldb::addr_t	link_map_addr,
		lldb::addr_t	base_addr,
		bool	base_addr_is_offset
	)

virtual

Locates or creates a module given by file and updates/loads the resulting module at the virtual base address base_addr.

Definition at line 152 of file DynamicLoader.cpp.

References lldb_private::ModuleList::AppendIfNeeded(), lldb_private::ConstString::AsCString(), lldb_private::ModuleList::FindFirstModule(), lldb_private::Target::GetArchitecture(), lldb_private::Process::GetFileLoadAddress(), lldb_private::Target::GetImages(), lldb_private::MemoryRegionInfo::GetMapped(), lldb_private::Process::GetMemoryRegionInfo(), lldb_private::MemoryRegionInfo::GetName(), lldb_private::Target::GetOrCreateModule(), lldb_private::MemoryRegionInfo::GetRange(), lldb_private::Range< B, S >::GetRangeBase(), lldb_private::Process::GetTarget(), lldb_private::ConstString::IsEmpty(), m_process, lldb_private::Process::ReadModuleFromMemory(), lldb_private::Status::Success(), and UpdateLoadedSections().

Referenced by GetThreadLocalData(), DynamicLoaderHexagonDYLD::LoadAllCurrentModules(), DynamicLoaderPOSIXDYLD::LoadAllCurrentModules(), lldb_private::process_gdb_remote::ProcessGDBRemote::LoadModuleAtAddress(), DynamicLoaderHexagonDYLD::RefreshModules(), and DynamicLoaderPOSIXDYLD::RefreshModules().

◆ LoadOperatingSystemPlugin()

void DynamicLoader::LoadOperatingSystemPlugin ( bool flush )

protected

Definition at line 240 of file DynamicLoader.cpp.

References lldb_private::Process::LoadOperatingSystemPlugin(), and m_process.

Referenced by GetSharedCacheInformation(), and DynamicLoaderDarwinKernel::LoadKernelModuleIfNeeded().

◆ ProcessDidExec()

virtual bool lldb_private::DynamicLoader::ProcessDidExec ( )

inlinevirtual

Helper function that can be used to detect when a process has called exec and is now a new and different process.

This can be called when necessary to try and detect the exec. The process might be able to answer this question, but sometimes it might not be able and the dynamic loader often knows what the program entry point is. So the process and the dynamic loader can work together to detect this.

Reimplemented in DynamicLoaderMacOSXDYLD, and DynamicLoaderMacOS.

Definition at line 107 of file DynamicLoader.h.

References GetStepThroughTrampolinePlan(), GetStopWhenImagesChange(), and SetStopWhenImagesChange().

Referenced by lldb_private::StopInfoMachException::CreateStopReasonWithMachException().

◆ ReadPointer()

addr_t DynamicLoader::ReadPointer ( lldb::addr_t addr )

protected

Definition at line 231 of file DynamicLoader.cpp.

References lldb_private::Status::Fail(), LLDB_INVALID_ADDRESS, m_process, and lldb_private::Process::ReadPointerFromMemory().

Referenced by GetSharedCacheInformation(), DynamicLoaderHexagonDYLD::GetThreadLocalData(), and DynamicLoaderPOSIXDYLD::GetThreadLocalData().

◆ ReadUnsignedIntWithSizeInBytes()

int64_t DynamicLoader::ReadUnsignedIntWithSizeInBytes	(	lldb::addr_t	addr,
		int	size_in_bytes
	)

protected

Definition at line 220 of file DynamicLoader.cpp.

References lldb_private::Status::Fail(), m_process, and lldb_private::Process::ReadUnsignedIntegerFromMemory().

Referenced by DynamicLoaderPOSIXDYLD::GetEntryPoint(), GetSharedCacheInformation(), and DynamicLoaderPOSIXDYLD::GetThreadLocalData().

◆ SetStopWhenImagesChange()

void DynamicLoader::SetStopWhenImagesChange ( bool stop )

Set whether the process should stop when images change.

When images (executables and shared libraries) get loaded or unloaded, often debug sessions will want to try and resolve or unresolve breakpoints that are set in these images. The default is set so that the process stops when images change, but this can be overridden using this function callback.

Parameters

[in] stop Boolean value that indicates whether the process should stop when images change.

Definition at line 72 of file DynamicLoader.cpp.

References m_process, and lldb_private::ProcessProperties::SetStopOnSharedLibraryEvents().

Referenced by ProcessDidExec().

◆ UnloadSections()

void DynamicLoader::UnloadSections ( const lldb::ModuleSP module )

protectedvirtual

Removes the loaded sections from the target in module.

Parameters

module The module to traverse.

Reimplemented in DynamicLoaderPOSIXDYLD, and DynamicLoaderHexagonDYLD.

Definition at line 123 of file DynamicLoader.cpp.

References UnloadSectionsCommon().

Referenced by GetSharedCacheInformation(), lldb_private::DynamicLoaderDarwin::UnloadAllImages(), and lldb_private::DynamicLoaderDarwin::UnloadImages().

◆ UnloadSectionsCommon()

void DynamicLoader::UnloadSectionsCommon ( const lldb::ModuleSP module )

protected

Definition at line 127 of file DynamicLoader.cpp.

References lldb_private::SectionList::GetSectionAtIndex(), GetSectionListFromModule(), lldb_private::SectionList::GetSize(), lldb_private::Process::GetTarget(), m_process, and lldb_private::Target::SetSectionUnloaded().

Referenced by GetSharedCacheInformation(), lldb_private::DynamicLoaderWindowsDYLD::OnUnloadModule(), DynamicLoaderPOSIXDYLD::UnloadSections(), and UnloadSections().

◆ UpdateLoadedSections()

void DynamicLoader::UpdateLoadedSections	(	lldb::ModuleSP	module,
		lldb::addr_t	link_map_addr,
		lldb::addr_t	base_addr,
		bool	base_addr_is_offset
	)

protectedvirtual

Updates the load address of every allocatable section in module.

Parameters

module	The module to traverse.
link_map_addr	The virtual address of the link map for the `module`.
base_addr	The virtual base address `module` is loaded at.

Reimplemented in DynamicLoaderPOSIXDYLD, and DynamicLoaderHexagonDYLD.

Definition at line 109 of file DynamicLoader.cpp.

References UpdateLoadedSectionsCommon().

Referenced by lldb_private::DynamicLoaderWindowsDYLD::DidAttach(), lldb_private::DynamicLoaderWindowsDYLD::DidLaunch(), GetSharedCacheInformation(), and LoadModuleAtAddress().

◆ UpdateLoadedSectionsCommon()

void DynamicLoader::UpdateLoadedSectionsCommon	(	lldb::ModuleSP	module,
		lldb::addr_t	base_addr,
		bool	base_addr_is_offset
	)

protected

Definition at line 115 of file DynamicLoader.cpp.

References lldb_private::Process::GetTarget(), and m_process.

Referenced by GetSharedCacheInformation(), lldb_private::DynamicLoaderWindowsDYLD::OnLoadModule(), DynamicLoaderPOSIXDYLD::UpdateLoadedSections(), and UpdateLoadedSections().

Member Data Documentation

◆ m_process

Process* lldb_private::DynamicLoader::m_process

protected

The process that this dynamic loader plug-in is tracking.

Definition at line 326 of file DynamicLoader.h.

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ DynamicLoader()

◆ ~DynamicLoader()

Member Function Documentation

◆ AlwaysRelyOnEHUnwindInfo()

◆ CanLoadImage()

◆ DidAttach()

◆ DidLaunch()

◆ FindEquivalentSymbols()

◆ FindPlugin()

◆ GetSectionListFromModule()

◆ GetSharedCacheInformation()

◆ GetStepThroughTrampolinePlan()

◆ GetStopWhenImagesChange()

◆ GetTargetExecutable()

◆ GetThreadLocalData()

◆ LoadModuleAtAddress()

◆ LoadOperatingSystemPlugin()

◆ ProcessDidExec()

◆ ReadPointer()

◆ ReadUnsignedIntWithSizeInBytes()

◆ SetStopWhenImagesChange()

◆ UnloadSections()

◆ UnloadSectionsCommon()

◆ UpdateLoadedSections()

◆ UpdateLoadedSectionsCommon()

Member Data Documentation

◆ m_process