#include <SymbolTable.h>

Collaboration diagram for SymbolTable:

Classes
class	Symbol

Public Types
enum	Binding { Local, Global, Weak }

enum	Policy { LocalFirst, NotOriginatingElf }

Public Member Functions
	SymbolTable (Elf *pElf)

	~SymbolTable ()

	SymbolTable (const SymbolTable &symtab)

void	copyTable (Elf *pNewElf, const SymbolTable &newSymtab)

void	insert (const String &name, Binding binding, Elf *pParent, uintptr_t value)

void	insertMultiple (SymbolTable pOther, const String &name, Binding binding, Elf pParent, uintptr_t value)

void	preallocate (size_t numGlobal, size_t numWeak, Elf *localElf, size_t numLocal)

void	preallocateAdditional (size_t numGlobal, size_t numWeak, Elf *localElf, size_t numLocal)

void	eraseByElf (Elf *pParent)

uintptr_t EXPORTED_PUBLIC	lookup (const HashedStringView &name, Elf pElf, Policy policy=LocalFirst, Binding pBinding=0)

Private Types
typedef HashTable< String, SharedPointer< Symbol >, HashedStringView >	symbolTree_t

typedef Tree< Elf *, SharedPointer< symbolTree_t > >	parentedSymbolTree_t

Private Member Functions
SymbolTable &	operator= (const SymbolTable &)

SharedPointer< Symbol >	doInsert (const String &name, Binding binding, Elf *pParent, uintptr_t value)

void	insertShared (const String &name, SharedPointer< Symbol > &symbol)

symbolTree_t *	getOrInsertTree (Elf *, Binding table=Local)

Private Attributes
parentedSymbolTree_t	m_LocalSymbols

parentedSymbolTree_t	m_GlobalSymbols

parentedSymbolTree_t	m_WeakSymbols

Elf *	m_pOriginatingElf

Mutex	m_Lock

Detailed Description

This class allows quick access to symbol information held within ELF files. The lookup operation allows multiple policies to retrieve the wanted symbol.

Note: Deletion is not implemented - the normal use case for this class is insertion and lookup. Deletion would almost never occur, and so the class is optimised solely for the first two operations.

Definition at line 43 of file SymbolTable.h.

Member Enumeration Documentation

enum SymbolTable::Binding

Binding types, to define how symbols interact.

Definition at line 47 of file SymbolTable.h.

enum SymbolTable::Policy

Lookup policies - given multiple definitions of a symbol, how do we determine the best response?

Enumerator
LocalFirst	Default policy - searches for local definitions of a symbol first.
NotOriginatingElf	Does not search the ELF given as pElf. This is used during lookups for R_COPY relocations, where one symbol must be linked to another.

Definition at line 56 of file SymbolTable.h.

Constructor & Destructor Documentation

SymbolTable::SymbolTable ( Elf * pElf )

Class constructor - creates an empty table.

Definition at line 30 of file SymbolTable.cc.

SymbolTable::~SymbolTable ( )

Destructor - destroys all information.

Definition at line 36 of file SymbolTable.cc.

SymbolTable::SymbolTable ( const SymbolTable & symtab )

Copy constructor.

Member Function Documentation

void SymbolTable::copyTable	(	Elf *	pNewElf,
		const SymbolTable &	newSymtab
	)

Copies the symbol table

Definition at line 40 of file SymbolTable.cc.

Referenced by Elf::Elf().

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SharedPointer< SymbolTable::Symbol > SymbolTable::doInsert	(	const String &	name,
		Binding	binding,
		Elf *	pParent,
		uintptr_t	value
	)

private

Insert doer.

Definition at line 99 of file SymbolTable.cc.

References insertShared().

Referenced by insert(), and insertMultiple().

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SymbolTable::symbolTree_t * SymbolTable::getOrInsertTree	(	Elf *	p,
		Binding	table = `Local`
	)

private

Get or insert a Symbol tree.

Definition at line 188 of file SymbolTable.cc.

References SharedPointer< T >::allocate(), Tree< K, E >::insert(), and Tree< K, E >::lookupRef().

Referenced by insertShared(), preallocate(), and preallocateAdditional().

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void SymbolTable::insert	(	const String &	name,
		Binding	binding,
		Elf *	pParent,
		uintptr_t	value
	)

Insert a symbol into the table.

Definition at line 51 of file SymbolTable.cc.

References doInsert().

Referenced by Elf::allocate(), KernelElf::initialise(), Elf::loadModule(), and Elf::populateSymbolTable().

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void SymbolTable::insertMultiple	(	SymbolTable *	pOther,
		const String &	name,
		Binding	binding,
		Elf *	pParent,
		uintptr_t	value
	)

Insert a symbol into two SymbolTables, using the memory once.

Definition at line 59 of file SymbolTable.cc.

References doInsert(), and insertShared().

Referenced by Elf::allocate().

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void SymbolTable::insertShared	(	const String &	name,
		SharedPointer< Symbol > &	symbol
	)

private

Insert the given shared symbol.

Definition at line 109 of file SymbolTable.cc.

References getOrInsertTree(), HashTable< K, V, SiblingK, InitialBuckets, QuadraticProbe, GrowthFactor >::insert(), and Tree< K, E >::remove().

Referenced by doInsert(), and insertMultiple().

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uintptr_t SymbolTable::lookup	(	const HashedStringView &	name,
		Elf *	pElf,
		Policy	policy = `LocalFirst`,
		Binding *	pBinding = `0`
	)

Looks up a symbol in the table, optionally outputting the binding value.

If the policy is set as "LocalFirst" (the default), then Local and Global definitions from pElf are given priority.

If the policy is set as "NotOriginatingElf", no symbols in pElf will ever be matched, preferring those from other ELFs. This is used for R_COPY relocations.