DWARF expression. More...

#include "llvm/IR/DebugInfoMetadata.h"

Inheritance diagram for llvm::DIExpression:

Collaboration diagram for llvm::DIExpression:

Classes
class	expr_op_iterator
	An iterator for expression operands. More...

class	ExprOperand
	A lightweight wrapper around an expression operand. More...

struct	FragmentInfo
	Holds the characteristics of one fragment of a larger variable. More...

Public Types
enum	PrependOps : uint8_t { ApplyOffset = 0, DerefBefore = 1 << 0, DerefAfter = 1 << 1, StackValue = 1 << 2 }
	Used for DIExpression::prepend. More...

using	element_iterator = ArrayRef< uint64_t >::iterator

Public Types inherited from llvm::MDNode
using	op_iterator = const MDOperand *

using	op_range = iterator_range< op_iterator >

Public Types inherited from llvm::Metadata
enum	MetadataKind

Public Member Functions
	DEFINE_MDNODE_GET (DIExpression,(ArrayRef< uint64_t > Elements),(Elements)) TempDIExpression clone() const

ArrayRef< uint64_t >	getElements () const

unsigned	getNumElements () const

uint64_t	getElement (unsigned I) const

bool	isConstant () const
	Determine whether this represents a standalone constant value. More...

element_iterator	elements_begin () const

element_iterator	elements_end () const

bool	isValid () const

bool	startsWithDeref () const
	Return whether the first element a DW_OP_deref. More...

Optional< FragmentInfo >	getFragmentInfo () const
	Retrieve the details of this fragment expression. More...

bool	isFragment () const
	Return whether this is a piece of an aggregate variable. More...

bool	isImplicit () const
	Return whether this is an implicit location description. More...

bool	extractIfOffset (int64_t &Offset) const
	If this is a constant offset, extract it. More...

int	fragmentCmp (const DIExpression *Other) const
	Determine the relative position of the fragments described by this DIExpression and `Other`. More...

bool	fragmentsOverlap (const DIExpression *Other) const
	Check if fragments overlap between this DIExpression and `Other`. More...


expr_op_iterator	expr_op_begin () const
	Visit the elements via ExprOperand wrappers. More...

expr_op_iterator	expr_op_end () const

iterator_range< expr_op_iterator >	expr_ops () const

Public Member Functions inherited from llvm::MDNode
	MDNode (const MDNode &)=delete

void	operator= (const MDNode &)=delete

void *	operator new (size_t)=delete

TempMDNode	clone () const
	Create a (temporary) clone of this. More...

LLVMContext &	getContext () const

void	replaceOperandWith (unsigned I, Metadata *New)
	Replace a specific operand. More...

bool	isResolved () const
	Check if node is fully resolved. More...

bool	isUniqued () const

bool	isDistinct () const

bool	isTemporary () const

void	replaceAllUsesWith (Metadata *MD)
	RAUW a temporary. More...

void	resolveCycles ()
	Resolve cycles. More...

void	resolve ()
	Resolve a unique, unresolved node. More...

op_iterator	op_begin () const

op_iterator	op_end () const

op_range	operands () const

const MDOperand &	getOperand (unsigned I) const

unsigned	getNumOperands () const
	Return number of MDNode operands. More...

bool	isTBAAVtableAccess () const
	Check whether MDNode is a vtable access. More...

Public Member Functions inherited from llvm::Metadata
unsigned	getMetadataID () const

void	dump () const
	User-friendly dump. More...

void	dump (const Module *M) const

void	print (raw_ostream &OS, const Module *M=nullptr, bool IsForDebug=false) const
	Print. More...

void	print (raw_ostream &OS, ModuleSlotTracker &MST, const Module *M=nullptr, bool IsForDebug=false) const

void	printAsOperand (raw_ostream &OS, const Module *M=nullptr) const
	Print as operand. More...

void	printAsOperand (raw_ostream &OS, ModuleSlotTracker &MST, const Module *M=nullptr) const

Static Public Member Functions
static bool	classof (const Metadata *MD)

static Optional< FragmentInfo >	getFragmentInfo (expr_op_iterator Start, expr_op_iterator End)
	Retrieve the details of this fragment expression. More...

static void	appendOffset (SmallVectorImpl< uint64_t > &Ops, int64_t Offset)
	Append `Ops` with operations to apply the `Offset`. More...

static const DIExpression *	extractAddressClass (const DIExpression *Expr, unsigned &AddrClass)
	Checks if the last 4 elements of the expression are DW_OP_constu <DWARF address="" space>=""> DW_OP_swap DW_OP_xderef and extracts the <DWARF address="" space>="">. More...

static DIExpression *	prepend (const DIExpression *Expr, uint8_t Flags, int64_t Offset=0)
	Prepend `DIExpr` with a deref and offset operation and optionally turn it into a stack value. More...

static DIExpression *	prependOpcodes (const DIExpression *Expr, SmallVectorImpl< uint64_t > &Ops, bool StackValue=false)
	Prepend `DIExpr` with the given opcodes and optionally turn it into a stack value. More...

static DIExpression *	append (const DIExpression *Expr, ArrayRef< uint64_t > Ops)
	Append the opcodes `Ops` to `DIExpr`. More...

static DIExpression *	appendToStack (const DIExpression *Expr, ArrayRef< uint64_t > Ops)
	Convert `DIExpr` into a stack value if it isn't one already by appending DW_OP_deref if needed, and appending `Ops` to the resulting expression. More...

static Optional< DIExpression * >	createFragmentExpression (const DIExpression *Expr, unsigned OffsetInBits, unsigned SizeInBits)
	Create a DIExpression to describe one part of an aggregate variable that is fragmented across multiple Values. More...

Static Public Member Functions inherited from llvm::MDNode
static MDTuple *	get (LLVMContext &Context, ArrayRef< Metadata *> MDs)

static MDTuple *	getIfExists (LLVMContext &Context, ArrayRef< Metadata *> MDs)

static MDTuple *	getDistinct (LLVMContext &Context, ArrayRef< Metadata *> MDs)

static TempMDTuple	getTemporary (LLVMContext &Context, ArrayRef< Metadata *> MDs)

static void	deleteTemporary (MDNode *N)
	Deallocate a node created by getTemporary. More...

template<class T >
static std::enable_if< std::is_base_of< MDNode, T >::value, T * >::type	replaceWithPermanent (std::unique_ptr< T, TempMDNodeDeleter > N)
	Replace a temporary node with a permanent one. More...

template<class T >
static std::enable_if< std::is_base_of< MDNode, T >::value, T * >::type	replaceWithUniqued (std::unique_ptr< T, TempMDNodeDeleter > N)
	Replace a temporary node with a uniqued one. More...

template<class T >
static std::enable_if< std::is_base_of< MDNode, T >::value, T * >::type	replaceWithDistinct (std::unique_ptr< T, TempMDNodeDeleter > N)
	Replace a temporary node with a distinct one. More...

static bool	classof (const Metadata *MD)
	Methods for support type inquiry through isa, cast, and dyn_cast: More...

static MDNode *	concatenate (MDNode A, MDNode B)
	Methods for metadata merging. More...

static MDNode *	intersect (MDNode A, MDNode B)

static MDNode *	getMostGenericTBAA (MDNode A, MDNode B)

static MDNode *	getMostGenericFPMath (MDNode A, MDNode B)

static MDNode *	getMostGenericRange (MDNode A, MDNode B)

static MDNode *	getMostGenericAliasScope (MDNode A, MDNode B)

static MDNode *	getMostGenericAlignmentOrDereferenceable (MDNode A, MDNode B)

Friends
class	LLVMContextImpl

class	MDNode

Additional Inherited Members
Protected Types inherited from llvm::MDNode
using	mutable_op_range = iterator_range< MDOperand * >

Protected Types inherited from llvm::Metadata
enum	StorageType { Uniqued, Distinct, Temporary }
	Active type of storage. More...

Protected Member Functions inherited from llvm::MDNode
	MDNode (LLVMContext &Context, unsigned ID, StorageType Storage, ArrayRef< Metadata > Ops1, ArrayRef< Metadata > Ops2=None)

	~MDNode ()=default

void *	operator new (size_t Size, unsigned NumOps)

void	operator delete (void *Mem)

void	operator delete (void *, unsigned)
	Required by std, but never called. More...

void	operator delete (void *, unsigned, bool)
	Required by std, but never called. More...

void	dropAllReferences ()

MDOperand *	mutable_begin ()

MDOperand *	mutable_end ()

mutable_op_range	mutable_operands ()

void	setOperand (unsigned I, Metadata *New)
	Set an operand. More...

void	storeDistinctInContext ()

Protected Member Functions inherited from llvm::Metadata
	Metadata (unsigned ID, StorageType Storage)

	~Metadata ()=default

void	handleChangedOperand (void , Metadata )
	Default handling of a changed operand, which asserts. More...

Static Protected Member Functions inherited from llvm::MDNode
template<class T , class StoreT >
static T *	storeImpl (T *N, StorageType Storage, StoreT &Store)

template<class T >
static T *	storeImpl (T *N, StorageType Storage)

Protected Attributes inherited from llvm::Metadata
unsigned char	Storage: 7
	Storage flag for non-uniqued, otherwise unowned, metadata. More...

unsigned char	ImplicitCode: 1

unsigned short	SubclassData16 = 0

unsigned	SubclassData32 = 0

Detailed Description

DWARF expression.

This is (almost) a DWARF expression that modifies the location of a variable, or the location of a single piece of a variable, or (when using DW_OP_stack_value) is the constant variable value.

TODO: Co-allocate the expression elements. TODO: Separate from MDNode, or otherwise drop Distinct and Temporary storage types.

Definition at line 2300 of file DebugInfoMetadata.h.

Member Typedef Documentation

◆ element_iterator

using llvm::DIExpression::element_iterator = ArrayRef<uint64_t>::iterator

Definition at line 2336 of file DebugInfoMetadata.h.

Member Enumeration Documentation

◆ PrependOps

enum llvm::DIExpression::PrependOps : uint8_t

Used for DIExpression::prepend.

Enumerator
ApplyOffset
DerefBefore
DerefAfter
StackValue

Definition at line 2481 of file DebugInfoMetadata.h.

Member Function Documentation

◆ append()

DIExpression * DIExpression::append	(	const DIExpression *	Expr,
		ArrayRef< uint64_t >	Ops
	)

static

Append the opcodes Ops to DIExpr.

Unlike appendToStack, the returned expression is a stack value only if DIExpr is a stack value. If DIExpr describes a fragment, the returned expression will describe the same fragment.

Definition at line 1022 of file DebugInfoMetadata.cpp.

References llvm::SmallVectorImpl< T >::append(), assert(), llvm::ArrayRef< T >::begin(), llvm::dwarf::DW_OP_LLVM_fragment, llvm::ArrayRef< T >::empty(), llvm::ArrayRef< T >::end(), expr_ops(), llvm::MDNode::get(), llvm::MDNode::getContext(), and llvm::None.

Referenced by appendToStack(), and llvm::LowerDbgDeclare().

◆ appendOffset()

void DIExpression::appendOffset	(	SmallVectorImpl< uint64_t > &	Ops,
		int64_t	Offset
	)

static

Append Ops with operations to apply the Offset.

Definition at line 927 of file DebugInfoMetadata.cpp.

References llvm::SmallVectorTemplateBase< T, bool >::push_back().

Referenced by replaceOneDbgValueForAlloca(), and llvm::salvageDebugInfoImpl().

◆ appendToStack()

DIExpression * DIExpression::appendToStack	(	const DIExpression *	Expr,
		ArrayRef< uint64_t >	Ops
	)

static

Convert DIExpr into a stack value if it isn't one already by appending DW_OP_deref if needed, and appending Ops to the resulting expression.

If DIExpr describes a fragment, the returned expression will describe the same fragment.

Definition at line 1044 of file DebugInfoMetadata.cpp.

References llvm::SmallVectorImpl< T >::append(), append(), assert(), llvm::ArrayRef< T >::back(), llvm::ArrayRef< T >::begin(), llvm::ArrayRef< T >::drop_back(), llvm::dwarf::DW_OP_LLVM_fragment, llvm::ArrayRef< T >::empty(), llvm::ArrayRef< T >::end(), getElements(), getFragmentInfo(), getNumElements(), llvm::Optional< T >::hasValue(), llvm::none_of(), and llvm::SmallVectorTemplateBase< T, bool >::push_back().

Referenced by llvm::replaceAllDbgUsesWith().

◆ classof()

static bool llvm::DIExpression::classof ( const Metadata * MD )

inlinestatic

Definition at line 2437 of file DebugInfoMetadata.h.

References llvm::Metadata::getMetadataID().

◆ createFragmentExpression()

Optional< DIExpression * > DIExpression::createFragmentExpression	(	const DIExpression *	Expr,
		unsigned	OffsetInBits,
		unsigned	SizeInBits
	)

static

Create a DIExpression to describe one part of an aggregate variable that is fragmented across multiple Values.

The DW_OP_LLVM_fragment operation will be appended to the elements of Expr. If Expr already contains a DW_OP_LLVM_fragment OffsetInBits is interpreted as an offset into the existing fragment.

Parameters

OffsetInBits	Offset of the piece in bits.
SizeInBits	Size of the piece in bits.

Returns: Creating a fragment expression may fail if Expr contains arithmetic operations that would be truncated.

Definition at line 1077 of file DebugInfoMetadata.cpp.

References assert(), llvm::dwarf::DW_OP_LLVM_fragment, expr_ops(), llvm::MDNode::get(), llvm::MDNode::getContext(), llvm::None, and llvm::SmallVectorTemplateBase< T, bool >::push_back().

Referenced by getUnderlyingArgReg(), llvm::SelectionDAGBuilder::handleDebugValue(), llvm::SelectionDAG::transferDbgValues(), and transferSRADebugInfo().

◆ DEFINE_MDNODE_GET()

llvm::DIExpression::DEFINE_MDNODE_GET	(	DIExpression	,
		(ArrayRef< uint64_t > Elements)	,
		(Elements)
	)		const

inline

Definition at line 2320 of file DebugInfoMetadata.h.

◆ elements_begin()

element_iterator llvm::DIExpression::elements_begin ( ) const

inline

Definition at line 2338 of file DebugInfoMetadata.h.

Referenced by llvm::DwarfCompileUnit::constructLabelDIE(), and rotateSign().

◆ elements_end()

element_iterator llvm::DIExpression::elements_end ( ) const

inline

Definition at line 2339 of file DebugInfoMetadata.h.

Referenced by llvm::DwarfCompileUnit::constructLabelDIE(), and rotateSign().

◆ expr_op_begin()

expr_op_iterator llvm::DIExpression::expr_op_begin ( ) const

inline

Visit the elements via ExprOperand wrappers.

These range iterators visit elements through ExprOperand wrappers. This is not guaranteed to be a valid range unless isValid() gives true.

Precondition: isValid() gives true.

Definition at line 2424 of file DebugInfoMetadata.h.

Referenced by llvm::DIExpressionCursor::DIExpressionCursor(), and llvm::DbgVariableLocation::extractFromMachineInstruction().

◆ expr_op_end()

expr_op_iterator llvm::DIExpression::expr_op_end ( ) const

inline

Definition at line 2427 of file DebugInfoMetadata.h.

Referenced by llvm::DIExpressionCursor::DIExpressionCursor(), and llvm::DbgVariableLocation::extractFromMachineInstruction().

◆ expr_ops()

iterator_range<expr_op_iterator> llvm::DIExpression::expr_ops ( ) const

inline

Definition at line 2430 of file DebugInfoMetadata.h.

Referenced by append(), createFragmentExpression(), emitDebugValueComment(), and prependOpcodes().

◆ extractAddressClass()

const DIExpression * DIExpression::extractAddressClass	(	const DIExpression *	Expr,
		unsigned &	AddrClass
	)

static

Checks if the last 4 elements of the expression are DW_OP_constu <DWARF address="" space>=""> DW_OP_swap DW_OP_xderef and extracts the <DWARF address="" space>="">.

Definition at line 964 of file DebugInfoMetadata.cpp.

References llvm::MDNode::get(), llvm::MDNode::getContext(), and llvm::makeArrayRef().

Referenced by llvm::DwarfCompileUnit::addLocationAttribute(), and llvm::DwarfCompileUnit::constructLabelDIE().