lldb_private::DWARFExpression Class Reference

"lldb/Expression/DWARFExpression.h" Encapsulates a DWARF location expression and interprets it. More...

#include <DWARFExpression.h>

Public Member Functions
	DWARFExpression ()
	DWARFExpression (const DataExtractor &data)
	Constructor.
virtual	~DWARFExpression ()
	Destructor.
bool	IsValid () const
	Return true if the location expression contains data.
lldb::addr_t	GetLocation_DW_OP_addr (const DWARFUnit *dwarf_cu, uint32_t op_addr_idx, bool &error) const
	If a location is not a location list, return true if the location contains a DW_OP_addr () opcode in the stream that matches file_addr.
bool	Update_DW_OP_addr (const DWARFUnit *dwarf_cu, lldb::addr_t file_addr)
void	UpdateValue (uint64_t const_value, lldb::offset_t const_value_byte_size, uint8_t addr_byte_size)
bool	ContainsThreadLocalStorage (const DWARFUnit *dwarf_cu) const
bool	LinkThreadLocalStorage (const DWARFUnit *dwarf_cu, std::function< lldb::addr_t(lldb::addr_t file_addr)> const &link_address_callback)
lldb::RegisterKind	GetRegisterKind () const
	Return the call-frame-info style register kind.
void	SetRegisterKind (lldb::RegisterKind reg_kind)
	Set the call-frame-info style register kind.
bool	GetExpressionData (DataExtractor &data) const
void	DumpLocation (Stream *s, lldb::DescriptionLevel level, ABI *abi) const
bool	MatchesOperand (StackFrame &frame, const Instruction::Operand &op) const

Static Public Member Functions
static bool	Evaluate (ExecutionContext *exe_ctx, RegisterContext *reg_ctx, lldb::ModuleSP module_sp, const DataExtractor &opcodes, const DWARFUnit *dwarf_cu, const lldb::RegisterKind reg_set, const Value *initial_value_ptr, const Value *object_address_ptr, Value &result, Status *error_ptr)
	Evaluate a DWARF location expression in a particular context.
static bool	ParseDWARFLocationList (const DWARFUnit *dwarf_cu, const DataExtractor &data, DWARFExpressionList *loc_list)

Private Attributes
DataExtractor	m_data
	A data extractor capable of reading opcode bytes.
lldb::RegisterKind	m_reg_kind = lldb::eRegisterKindDWARF
	One of the defines that starts with LLDB_REGKIND_.

Detailed Description

"lldb/Expression/DWARFExpression.h" Encapsulates a DWARF location expression and interprets it.

DWARF location expressions are used in two ways by LLDB. The first use is to find entities specified in the debug information, since their locations are specified in precisely this language. The second is to interpret expressions without having to run the target in cases where the overhead from copying JIT-compiled code into the target is too high or where the target cannot be run. This class encapsulates a single DWARF location expression or a location list and interprets it.

Definition at line 36 of file DWARFExpression.h.

Constructor & Destructor Documentation

DWARFExpression() [1/2]

DWARFExpression::DWARFExpression

(

)

Definition at line 50 of file DWARFExpression.cpp.

Referenced by ParseDWARFLocationList().

DWARFExpression() [2/2]

DWARFExpression::DWARFExpression

(

const DataExtractor &

data

)

Constructor.

Parameters

[in]

data

A data extractor configured to read the DWARF location expression's bytecode.

Definition at line 52 of file DWARFExpression.cpp.

~DWARFExpression()

DWARFExpression::~DWARFExpression ( )

virtualdefault

Destructor.

Member Function Documentation

ContainsThreadLocalStorage()

bool DWARFExpression::ContainsThreadLocalStorage

(

const DWARFUnit *

dwarf_cu

)

const

Definition at line 433 of file DWARFExpression.cpp.

References GetOpcodeDataSize(), lldb_private::DataExtractor::GetU8(), LLDB_INVALID_OFFSET, m_data, and lldb_private::DataExtractor::ValidOffset().

Referenced by lldb_private::DWARFExpressionList::ContainsThreadLocalStorage().

DumpLocation()

void DWARFExpression::DumpLocation	(	Stream *	s,
		lldb::DescriptionLevel	level,
		ABI *	abi
	)		const

Definition at line 71 of file DWARFExpression.cpp.

References lldb_private::Stream::AsRawOstream(), lldb_private::DataExtractor::GetAddressByteSize(), lldb_private::DataExtractor::GetAsLLVM(), lldb_private::ABI::GetMCRegisterInfo(), and m_data.

Referenced by SymbolFileDWARF::ParseVariableDIE().

Evaluate()

bool DWARFExpression::Evaluate ( ExecutionContext *  exe_ctx, RegisterContext *  reg_ctx, lldb::ModuleSP  module_sp, const DataExtractor &  opcodes, const DWARFUnit *  dwarf_cu, const lldb::RegisterKind  reg_set, const Value *  initial_value_ptr, const Value *  object_address_ptr, Value &  result, Status *  error_ptr  )

static

Evaluate a DWARF location expression in a particular context.

Parameters

[in]	exe_ctx	The execution context in which to evaluate the location expression. The location expression may access the target's memory, especially if it comes from the expression parser.
[in]	opcode_ctx	The module which defined the expression.
[in]	opcodes	This is a static method so the opcodes need to be provided explicitly.
[in]	reg_ctx	An optional parameter which provides a RegisterContext for use when evaluating the expression (i.e. for fetching register values). Normally this will come from the ExecutionContext's StackFrame but in the case where an expression needs to be evaluated while building the stack frame list, this short-cut is available.
[in]	reg_set	The call-frame-info style register kind.
[in]	initial_value_ptr	A value to put on top of the interpreter stack before evaluating the expression, if the expression is parametrized. Can be NULL.
[in]	result	A value into which the result of evaluating the expression is to be placed.
[in]	error_ptr	If non-NULL, used to report errors in expression evaluation.

Returns

True on success; false otherwise. If error_ptr is non-NULL, details of the failure are provided through it.

Insertion point for evaluating multi-piece expression.

Definition at line 856 of file DWARFExpression.cpp.

References lldb_private::Value::AppendDataToHostBuffer(), lldb_private::Value::ClearContext(), DerefSizeExtractDataHelper(), lldb_private::DW_OP_value_to_name(), lldb_private::ArchSpec::eCore_wasm32, error(), Evaluate_DW_OP_entry_value(), lldb_private::Expressions, lldb_private::Scalar::ExtractBitfield(), lldb_private::Value::FileAddress, lldb_private::Process::GetABI(), lldb_private::DataExtractor::GetAddress(), lldb_private::DataExtractor::GetAddressByteSize(), lldb_private::Target::GetArchitecture(), DWARFBaseDIE::GetAttributeValueAsUnsigned(), lldb_private::Value::GetBuffer(), lldb_private::Process::GetByteOrder(), lldb_private::ObjectFile::GetByteOrder(), lldb_private::DataExtractor::GetByteSize(), lldb_private::Scalar::GetByteSize(), lldb_private::DataBufferHeap::GetByteSize(), lldb_private::StackID::GetCallFrameAddress(), lldb_private::ArchSpec::GetCore(), lldb_private::StreamString::GetData(), lldb_private::DataExtractor::GetData(), lldb_private::StackFrame::GetFrameBaseValue(), lldb_private::ExecutionContext::GetFramePtr(), lldb_private::GetLog(), DWARFUnit::GetOffset(), lldb_private::ExecutionContext::GetProcessPtr(), lldb_private::StackFrame::GetRegisterContext(), lldb_private::Value::GetScalar(), lldb_private::DataExtractor::GetSLEB128(), lldb_private::StackFrame::GetStackID(), DWARFUnit::GetSymbolFileDWARF(), lldb_private::ExecutionContext::GetTargetPtr(), lldb_private::Thread::GetThreadLocalData(), lldb_private::ExecutionContext::GetThreadPtr(), lldb_private::DataExtractor::GetU16(), lldb_private::DataExtractor::GetU32(), lldb_private::DataExtractor::GetU64(), lldb_private::DataExtractor::GetU8(), lldb_private::DataExtractor::GetULEB128(), lldb_private::Value::GetValueType(), lldb_private::Log::GetVerbose(), lldb_private::Value::HostAddress, lldb_private::Value::Invalid, lldb_private::Address::IsSectionOffset(), lldb_private::Scalar::IsZero(), LLDB_ERRORF, LLDB_INVALID_ADDRESS, LLDB_LOG, LLDB_LOGF, lldb_private::Value::LoadAddress, lldb_private::Scalar::MakeSigned(), lldb_private::Memory, SymbolFileDWARF::ParseVendorDWARFOpcode(), lldb_private::Stream::Printf(), DWARFUnit::ReadAddressFromDebugAddrSection(), lldb_private::Target::ReadMemory(), lldb_private::Process::ReadMemory(), lldb_private::Process::ReadPointerFromMemory(), ReadRegisterValueAsScalar(), lldb_private::Value::ResizeData(), ResolveLoadAddress(), lldb_private::Value::ResolveValue(), lldb_private::Value::Scalar, lldb_private::Status::SetErrorString(), lldb_private::Status::SetErrorStringWithFormat(), lldb_private::Status::SetErrorStringWithFormatv(), lldb_private::Scalar::TruncOrExtendTo(), lldb_private::Scalar::UInt128(), lldb_private::Scalar::ULongLong(), and lldb_private::DataExtractor::ValidOffset().

Referenced by lldb_private::DWARFExpressionList::Evaluate(), and DWARFASTParserClang::ParseInheritance().

GetExpressionData()

bool lldb_private::DWARFExpression::GetExpressionData ( DataExtractor &  data ) const

inline

Definition at line 149 of file DWARFExpression.h.

References lldb_private::DataExtractor::GetByteSize(), and m_data.

Referenced by lldb_private::DWARFExpressionList::Evaluate().

GetLocation_DW_OP_addr()

lldb::addr_t DWARFExpression::GetLocation_DW_OP_addr	(	const DWARFUnit *	dwarf_cu,
		uint32_t	op_addr_idx,
		bool &	error
	)		const

If a location is not a location list, return true if the location contains a DW_OP_addr () opcode in the stream that matches file_addr.

If file_addr is LLDB_INVALID_ADDRESS, the this function will return true if the variable there is any DW_OP_addr in a location that (yet still is NOT a location list). This helps us detect if a variable is a global or static variable since there is no other indication from DWARF debug info.

Parameters

[in]	dwarf_cu	The dwarf unit this expression belongs to.
[in]	op_addr_idx	The DW_OP_addr index to retrieve in case there is more than one DW_OP_addr opcode in the location byte stream.
[out]	error	If the location stream contains unknown DW_OP opcodes or the data is missing, error will be set to true.

Returns

LLDB_INVALID_ADDRESS if the location doesn't contain a DW_OP_addr for op_addr_idx, otherwise a valid file address

Definition at line 357 of file DWARFExpression.cpp.

References error(), lldb_private::DataExtractor::GetAddress(), GetOpcodeDataSize(), lldb_private::DataExtractor::GetU8(), lldb_private::DataExtractor::GetULEB128(), LLDB_INVALID_ADDRESS, LLDB_INVALID_OFFSET, m_data, DWARFUnit::ReadAddressFromDebugAddrSection(), and lldb_private::DataExtractor::ValidOffset().

Referenced by SymbolFileDWARF::ParseVariableDIE().

GetRegisterKind()

RegisterKind DWARFExpression::GetRegisterKind

(

)

const

Return the call-frame-info style register kind.

Definition at line 90 of file DWARFExpression.cpp.

References m_reg_kind.

Referenced by lldb_private::DWARFExpressionList::Evaluate().

IsValid()

bool DWARFExpression::IsValid

(

)

const

Return true if the location expression contains data.

Definition at line 57 of file DWARFExpression.cpp.

References lldb_private::DataExtractor::GetByteSize(), and m_data.

LinkThreadLocalStorage()

bool DWARFExpression::LinkThreadLocalStorage	(	const DWARFUnit *	dwarf_cu,
		std::function< lldb::addr_t(lldb::addr_t file_addr)> const &	link_address_callback
	)

Definition at line 449 of file DWARFExpression.cpp.

References lldb_private::DataExtractor::GetAddressByteSize(), lldb_private::DataExtractor::GetByteOrder(), lldb_private::DataExtractor::GetByteSize(), lldb_private::DataExtractor::GetDataStart(), GetOpcodeDataSize(), lldb_private::DataExtractor::GetU32(), lldb_private::DataExtractor::GetU64(), lldb_private::DataExtractor::GetU8(), LLDB_INVALID_ADDRESS, LLDB_INVALID_OFFSET, m_data, lldb_private::DataExtractor::SetData(), UINT32_MAX, and lldb_private::DataExtractor::ValidOffset().

Referenced by lldb_private::DWARFExpressionList::LinkThreadLocalStorage().

MatchesOperand()

bool DWARFExpression::MatchesOperand	(	StackFrame &	frame,
		const Instruction::Operand &	op
	)		const

Definition at line 2662 of file DWARFExpression.cpp.

References lldb_private::Instruction::Operand::Dereference, lldb_private::StackFrame::GetFrameBaseExpression(), lldb_private::StackFrame::GetRegisterContext(), lldb_private::DataExtractor::GetSLEB128(), lldb_private::DataExtractor::GetU8(), lldb_private::DataExtractor::GetULEB128(), m_data, m_reg_kind, lldb_private::DWARFExpressionList::MatchesOperand(), and lldb_private::Instruction::Operand::Sum.

Referenced by lldb_private::DWARFExpressionList::MatchesOperand().

ParseDWARFLocationList()

bool DWARFExpression::ParseDWARFLocationList ( const DWARFUnit *  dwarf_cu, const DataExtractor &  data, DWARFExpressionList *  loc_list  )

static

Definition at line 2625 of file DWARFExpression.cpp.

References lldb_private::DWARFExpressionList::AddExpression(), lldb_private::DWARFExpressionList::Clear(), DWARFExpression(), error(), lldb_private::Expressions, lldb_private::DataExtractor::GetAddressByteSize(), DWARFUnit::GetBaseAddress(), lldb_private::DataExtractor::GetByteOrder(), DWARFUnit::GetLocationTable(), lldb_private::GetLog(), LLDB_INVALID_ADDRESS, LLDB_LOG_ERROR, DWARFUnit::ReadAddressFromDebugAddrSection(), and lldb_private::DWARFExpressionList::Sort().

Referenced by DWARFDebugInfoEntry::GetDIENamesAndRanges(), and SymbolFileDWARF::ParseVariableDIE().

SetRegisterKind()

void DWARFExpression::SetRegisterKind

(

lldb::RegisterKind

reg_kind

)

Set the call-frame-info style register kind.

Parameters

[in]

reg_kind

The register kind.

Definition at line 92 of file DWARFExpression.cpp.

References m_reg_kind.

Referenced by ConvertPDBLocationToDWARFExpression(), MakeLocationExpressionInternal(), lldb_private::RegisterContextUnwind::ReadFrameAddress(), and lldb_private::RegisterContextUnwind::SavedLocationForRegister().

Update_DW_OP_addr()

bool DWARFExpression::Update_DW_OP_addr	(	const DWARFUnit *	dwarf_cu,
		lldb::addr_t	file_addr
	)

Definition at line 395 of file DWARFExpression.cpp.

References lldb_private::DataExtractor::GetAddressByteSize(), lldb_private::DataExtractor::GetByteOrder(), lldb_private::DataExtractor::GetByteSize(), lldb_private::DataExtractor::GetDataStart(), GetOpcodeDataSize(), lldb_private::DataExtractor::GetU8(), LLDB_INVALID_OFFSET, m_data, lldb_private::DataExtractor::SetData(), UINT32_MAX, and lldb_private::DataExtractor::ValidOffset().

Referenced by SymbolFileDWARF::ParseVariableDIE().

UpdateValue()

void DWARFExpression::UpdateValue	(	uint64_t	const_value,
		lldb::offset_t	const_value_byte_size,
		uint8_t	addr_byte_size
	)

Definition at line 59 of file DWARFExpression.cpp.

References lldb_private::endian::InlHostByteOrder(), m_data, lldb_private::DataExtractor::SetAddressByteSize(), lldb_private::DataExtractor::SetByteOrder(), and lldb_private::DataExtractor::SetData().

Referenced by SymbolFileDWARF::ParseVariableDIE().

Member Data Documentation

m_data

DataExtractor lldb_private::DWARFExpression::m_data

private

A data extractor capable of reading opcode bytes.

Definition at line 160 of file DWARFExpression.h.

Referenced by ContainsThreadLocalStorage(), DumpLocation(), GetExpressionData(), GetLocation_DW_OP_addr(), IsValid(), LinkThreadLocalStorage(), MatchesOperand(), Update_DW_OP_addr(), and UpdateValue().

m_reg_kind

lldb::RegisterKind lldb_private::DWARFExpression::m_reg_kind = lldb::eRegisterKindDWARF

private

One of the defines that starts with LLDB_REGKIND_.

Definition at line 163 of file DWARFExpression.h.

Referenced by GetRegisterKind(), MatchesOperand(), and SetRegisterKind().

---

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

• DWARFExpression.h
• DWARFExpression.cpp