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lldb_private::DWARFExpression Class Reference

#include <DWARFExpression.h>

Collaboration diagram for lldb_private::DWARFExpression:
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Classes

struct  LoclistAddresses
 

Public Member Functions

 DWARFExpression ()
 
 DWARFExpression (lldb::ModuleSP module, const DataExtractor &data, const DWARFUnit *dwarf_cu)
 Constructor. More...
 
virtual ~DWARFExpression ()
 Destructor. More...
 
void GetDescription (Stream *s, lldb::DescriptionLevel level, lldb::addr_t location_list_base_addr, ABI *abi) const
 Print the description of the expression to a stream. More...
 
bool IsValid () const
 Return true if the location expression contains data. More...
 
bool IsLocationList () const
 Return true if a location list was provided. More...
 
bool LocationListContainsAddress (lldb::addr_t func_load_addr, lldb::addr_t addr) const
 Search for a load address in the location list. More...
 
lldb::addr_t GetLocation_DW_OP_addr (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. More...
 
bool Update_DW_OP_addr (lldb::addr_t file_addr)
 
void UpdateValue (uint64_t const_value, lldb::offset_t const_value_byte_size, uint8_t addr_byte_size)
 
void SetModule (const lldb::ModuleSP &module)
 
bool ContainsThreadLocalStorage () const
 
bool LinkThreadLocalStorage (lldb::ModuleSP new_module_sp, std::function< lldb::addr_t(lldb::addr_t file_addr)> const &link_address_callback)
 
void SetLocationListAddresses (lldb::addr_t cu_file_addr, lldb::addr_t func_file_addr)
 Tells the expression that it refers to a location list. More...
 
int GetRegisterKind ()
 Return the call-frame-info style register kind. More...
 
void SetRegisterKind (lldb::RegisterKind reg_kind)
 Set the call-frame-info style register kind. More...
 
bool Evaluate (ExecutionContextScope *exe_scope, lldb::addr_t func_load_addr, const Value *initial_value_ptr, const Value *object_address_ptr, Value &result, Status *error_ptr) const
 Wrapper for the static evaluate function that accepts an ExecutionContextScope instead of an ExecutionContext and uses member variables to populate many operands. More...
 
bool Evaluate (ExecutionContext *exe_ctx, RegisterContext *reg_ctx, lldb::addr_t loclist_base_load_addr, const Value *initial_value_ptr, const Value *object_address_ptr, Value &result, Status *error_ptr) const
 Wrapper for the static evaluate function that uses member variables to populate many operands. More...
 
bool GetExpressionData (DataExtractor &data) const
 
bool DumpLocationForAddress (Stream *s, lldb::DescriptionLevel level, lldb::addr_t func_load_addr, lldb::addr_t address, ABI *abi)
 
bool MatchesOperand (StackFrame &frame, const Instruction::Operand &op)
 
llvm::Optional< DataExtractorGetLocationExpression (lldb::addr_t load_function_start, lldb::addr_t addr) const
 

Static Public Member Functions

static bool Evaluate (ExecutionContext *exe_ctx, RegisterContext *reg_ctx, lldb::ModuleSP opcode_ctx, 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. More...
 

Private Member Functions

void DumpLocation (Stream *s, const DataExtractor &data, lldb::DescriptionLevel level, ABI *abi) const
 Pretty-prints the location expression to a stream. More...
 

Private Attributes

lldb::ModuleWP m_module_wp
 Module which defined this expression. More...
 
DataExtractor m_data
 A data extractor capable of reading opcode bytes. More...
 
const DWARFUnitm_dwarf_cu
 The DWARF compile unit this expression belongs to. More...
 
lldb::RegisterKind m_reg_kind
 One of the defines that starts with LLDB_REGKIND_. More...
 
llvm::Optional< LoclistAddressesm_loclist_addresses
 

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 35 of file DWARFExpression.h.

Constructor & Destructor Documentation

◆ DWARFExpression() [1/2]

DWARFExpression::DWARFExpression ( )

Definition at line 58 of file DWARFExpression.cpp.

◆ DWARFExpression() [2/2]

DWARFExpression::DWARFExpression ( lldb::ModuleSP  module,
const DataExtractor data,
const DWARFUnit dwarf_cu 
)

Constructor.

Parameters
[in]dataA data extractor configured to read the DWARF location expression's bytecode.

Definition at line 62 of file DWARFExpression.cpp.

References m_module_wp.

◆ ~DWARFExpression()

DWARFExpression::~DWARFExpression ( )
virtual

Destructor.

Definition at line 72 of file DWARFExpression.cpp.

Member Function Documentation

◆ ContainsThreadLocalStorage()

bool DWARFExpression::ContainsThreadLocalStorage ( ) const

◆ DumpLocation()

void DWARFExpression::DumpLocation ( Stream s,
const DataExtractor data,
lldb::DescriptionLevel  level,
ABI abi 
) const
private

Pretty-prints the location expression to a stream.

Parameters
[in]sThe stream to use for pretty-printing.
[in]dataThe data extractor.
[in]levelThe level of detail to use in pretty-printing.
[in]abiAn optional ABI plug-in that can be used to resolve register names.

Definition at line 88 of file DWARFExpression.cpp.

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

Referenced by DumpLocationForAddress(), and GetDescription().

◆ DumpLocationForAddress()

bool DWARFExpression::DumpLocationForAddress ( Stream s,
lldb::DescriptionLevel  level,
lldb::addr_t  func_load_addr,
lldb::addr_t  address,
ABI abi 
)

◆ Evaluate() [1/3]

bool DWARFExpression::Evaluate ( ExecutionContext exe_ctx,
RegisterContext reg_ctx,
lldb::addr_t  loclist_base_load_addr,
const Value initial_value_ptr,
const Value object_address_ptr,
Value result,
Status error_ptr 
) const

◆ Evaluate() [2/3]

bool DWARFExpression::Evaluate ( ExecutionContext exe_ctx,
RegisterContext reg_ctx,
lldb::ModuleSP  opcode_ctx,
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_ctxThe 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_ctxThe module which defined the expression.
[in]opcodesThis is a static method so the opcodes need to be provided explicitly.
[in]reg_ctxAn 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_setThe call-frame-info style register kind.
[in]initial_value_ptrA value to put on top of the interpreter stack before evaluating the expression, if the expression is parametrized. Can be NULL.
[in]resultA value into which the result of evaluating the expression is to be placed.
[in]error_ptrIf 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 953 of file DWARFExpression.cpp.

References lldb_private::Value::AppendDataToHostBuffer(), lldb_private::StackFrame::CalculateTarget(), lldb_private::Value::ClearContext(), lldb_private::DW_OP_value_to_name(), error(), Evaluate_DW_OP_entry_value(), lldb_private::Scalar::ExtractBitfield(), lldb_private::Value::FileAddress, lldb_private::Process::GetABI(), lldb_private::DataExtractor::GetAddress(), lldb_private::DataExtractor::GetAddressByteSize(), DWARFBaseDIE::GetAttributeValueAsUnsigned(), lldb_private::Value::GetBuffer(), lldb_private::Process::GetByteOrder(), lldb_private::DataBufferHeap::GetBytes(), lldb_private::DataBufferHeap::GetByteSize(), lldb_private::Scalar::GetByteSize(), lldb_private::DataExtractor::GetByteSize(), lldb_private::StackID::GetCallFrameAddress(), lldb_private::StreamString::GetData(), lldb_private::DataExtractor::GetData(), lldb_private::StackFrame::GetFrameBaseValue(), lldb_private::ExecutionContext::GetFramePtr(), lldb_private::Address::GetLoadAddress(), lldb_private::GetLogIfAllCategoriesSet(), lldb_private::ExecutionContext::GetProcessPtr(), lldb_private::StackFrame::GetRegisterContext(), lldb_private::Value::GetScalar(), lldb_private::DataExtractor::GetSLEB128(), lldb_private::StackFrame::GetStackID(), 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::Scalar::IsZero(), LIBLLDB_LOG_EXPRESSIONS, LLDB_ERRORF, LLDB_INVALID_ADDRESS, LLDB_LOG, LLDB_LOGF, lldb_private::Value::LoadAddress, lldb_private::Stream::Printf(), ReadAddressFromDebugAddrSection(), lldb_private::Process::ReadMemory(), lldb_private::Process::ReadPointerFromMemory(), ReadRegisterValueAsScalar(), lldb_private::Value::ResizeData(), 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().

◆ Evaluate() [3/3]

bool DWARFExpression::Evaluate ( ExecutionContextScope exe_scope,
lldb::addr_t  func_load_addr,
const Value initial_value_ptr,
const Value object_address_ptr,
Value result,
Status error_ptr 
) const

◆ GetDescription()

void DWARFExpression::GetDescription ( Stream s,
lldb::DescriptionLevel  level,
lldb::addr_t  location_list_base_addr,
ABI abi 
) const

Print the description of the expression to a stream.

Parameters
[in]sThe stream to print to.
[in]levelThe level of verbosity to use.
[in]location_list_base_addrIf this is a location list based expression, this is the address of the object that owns it. NOTE: this value is different from the DWARF version of the location list base address which is compile unit relative. This base address is the address of the object that owns the location list.
[in]abiAn optional ABI plug-in that can be used to resolve register names.

Definition at line 130 of file DWARFExpression.cpp.

References lldb_private::Stream::AsRawOstream(), DumpLocation(), lldb::eByteOrderLittle, lldb_private::DataExtractor::GetByteOrder(), lldb_private::Stream::GetIndentLevel(), DWARFUnit::GetLocationTable(), lldb_private::ABI::GetMCRegisterInfo(), IsLocationList(), m_data, m_dwarf_cu, and lldb_private::breakpad::toString().

Referenced by lldb_private::Variable::Dump().

◆ GetExpressionData()

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

◆ GetLocation_DW_OP_addr()

lldb::addr_t DWARFExpression::GetLocation_DW_OP_addr ( 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]op_addr_idxThe DW_OP_addr index to retrieve in case there is more than one DW_OP_addr opcode in the location byte stream.
[out]errorIf 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 412 of file DWARFExpression.cpp.

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

Referenced by SymbolFileDWARF::ParseVariableDIE().

◆ GetLocationExpression()

llvm::Optional< DataExtractor > DWARFExpression::GetLocationExpression ( lldb::addr_t  load_function_start,
lldb::addr_t  addr 
) const

◆ GetRegisterKind()

int DWARFExpression::GetRegisterKind ( )

Return the call-frame-info style register kind.

Definition at line 101 of file DWARFExpression.cpp.

References m_reg_kind.

◆ IsLocationList()

bool DWARFExpression::IsLocationList ( ) const

◆ IsValid()

bool DWARFExpression::IsValid ( ) const

Return true if the location expression contains data.

Definition at line 74 of file DWARFExpression.cpp.

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

Referenced by lldb_private::Variable::Dump(), DWARFASTParserClang::ParseFunctionFromDWARF(), and SymbolFileDWARF::ParseVariableDIE().

◆ LinkThreadLocalStorage()

bool DWARFExpression::LinkThreadLocalStorage ( lldb::ModuleSP  new_module_sp,
std::function< lldb::addr_t(lldb::addr_t file_addr)> const &  link_address_callback 
)

◆ LocationListContainsAddress()

bool DWARFExpression::LocationListContainsAddress ( lldb::addr_t  func_load_addr,
lldb::addr_t  addr 
) const

Search for a load address in the location list.

Parameters
[in]func_load_addrThe actual address of the function containing this location list.
[in]addrThe address to resolve
Returns
True if IsLocationList() is true and the address was found; false otherwise.

Definition at line 612 of file DWARFExpression.cpp.

References GetLocationExpression(), IsLocationList(), and LLDB_INVALID_ADDRESS.

Referenced by lldb_private::Variable::LocationIsValidForAddress(), and lldb_private::Variable::LocationIsValidForFrame().

◆ MatchesOperand()

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

◆ SetLocationListAddresses()

void DWARFExpression::SetLocationListAddresses ( lldb::addr_t  cu_file_addr,
lldb::addr_t  func_file_addr 
)

Tells the expression that it refers to a location list.

Parameters
[in]cu_file_addrThe base address to use for interpreting relative location list entries.
[in]func_file_addrThe file address of the function containing this location list. This address will be used to relocate the location list on the fly (in conjuction with the func_load_addr arguments).

Definition at line 96 of file DWARFExpression.cpp.

References m_loclist_addresses.

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

◆ SetModule()

void lldb_private::DWARFExpression::SetModule ( const lldb::ModuleSP &  module)
inline

Definition at line 121 of file DWARFExpression.h.

References m_module_wp.

Referenced by SymbolFileDWARF::ParseVariableDIE().

◆ SetRegisterKind()

void DWARFExpression::SetRegisterKind ( lldb::RegisterKind  reg_kind)

Set the call-frame-info style register kind.

Parameters
[in]reg_kindThe register kind.

Definition at line 103 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 ( lldb::addr_t  file_addr)

◆ UpdateValue()

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

Member Data Documentation

◆ m_data

DataExtractor lldb_private::DWARFExpression::m_data
private

◆ m_dwarf_cu

const DWARFUnit* lldb_private::DWARFExpression::m_dwarf_cu
private

The DWARF compile unit this expression belongs to.

It is used to evaluate values indexing into the .debug_addr section (e.g. DW_OP_GNU_addr_index, DW_OP_GNU_const_index)

Definition at line 253 of file DWARFExpression.h.

Referenced by Evaluate(), GetDescription(), GetLocation_DW_OP_addr(), and GetLocationExpression().

◆ m_loclist_addresses

llvm::Optional<LoclistAddresses> lldb_private::DWARFExpression::m_loclist_addresses
private

◆ m_module_wp

lldb::ModuleWP lldb_private::DWARFExpression::m_module_wp
private

Module which defined this expression.

Definition at line 245 of file DWARFExpression.h.

Referenced by DWARFExpression(), Evaluate(), LinkThreadLocalStorage(), and SetModule().

◆ m_reg_kind

lldb::RegisterKind lldb_private::DWARFExpression::m_reg_kind
private

One of the defines that starts with LLDB_REGKIND_.

Definition at line 256 of file DWARFExpression.h.

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


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