142 lines
5.4 KiB
C++
142 lines
5.4 KiB
C++
//===- SymbolTable.h --------------------------------------------*- C++ -*-===//
|
|
//
|
|
// The LLVM Linker
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLD_ELF_SYMBOL_TABLE_H
|
|
#define LLD_ELF_SYMBOL_TABLE_H
|
|
|
|
#include "InputFiles.h"
|
|
#include "LTO.h"
|
|
#include "Strings.h"
|
|
#include "llvm/ADT/CachedHashString.h"
|
|
#include "llvm/ADT/DenseMap.h"
|
|
|
|
namespace lld {
|
|
namespace elf {
|
|
|
|
struct Symbol;
|
|
|
|
// SymbolTable is a bucket of all known symbols, including defined,
|
|
// undefined, or lazy symbols (the last one is symbols in archive
|
|
// files whose archive members are not yet loaded).
|
|
//
|
|
// We put all symbols of all files to a SymbolTable, and the
|
|
// SymbolTable selects the "best" symbols if there are name
|
|
// conflicts. For example, obviously, a defined symbol is better than
|
|
// an undefined symbol. Or, if there's a conflict between a lazy and a
|
|
// undefined, it'll read an archive member to read a real definition
|
|
// to replace the lazy symbol. The logic is implemented in the
|
|
// add*() functions, which are called by input files as they are parsed. There
|
|
// is one add* function per symbol type.
|
|
class SymbolTable {
|
|
public:
|
|
template <class ELFT> void addFile(InputFile *File);
|
|
template <class ELFT> void addCombinedLTOObject();
|
|
template <class ELFT> void addSymbolAlias(StringRef Alias, StringRef Name);
|
|
template <class ELFT> void addSymbolWrap(StringRef Name);
|
|
void applySymbolRenames();
|
|
|
|
ArrayRef<Symbol *> getSymbols() const { return SymVector; }
|
|
|
|
template <class ELFT>
|
|
DefinedRegular *addAbsolute(StringRef Name,
|
|
uint8_t Visibility = llvm::ELF::STV_HIDDEN,
|
|
uint8_t Binding = llvm::ELF::STB_GLOBAL);
|
|
template <class ELFT>
|
|
DefinedRegular *addIgnored(StringRef Name,
|
|
uint8_t Visibility = llvm::ELF::STV_HIDDEN);
|
|
|
|
template <class ELFT> Symbol *addUndefined(StringRef Name);
|
|
template <class ELFT>
|
|
Symbol *addUndefined(StringRef Name, bool IsLocal, uint8_t Binding,
|
|
uint8_t StOther, uint8_t Type, bool CanOmitFromDynSym,
|
|
InputFile *File);
|
|
template <class ELFT>
|
|
Symbol *addRegular(StringRef Name, uint8_t StOther, uint8_t Type,
|
|
uint64_t Value, uint64_t Size, uint8_t Binding,
|
|
SectionBase *Section, InputFile *File);
|
|
|
|
template <class ELFT>
|
|
void addShared(SharedFile<ELFT> *F, StringRef Name,
|
|
const typename ELFT::Sym &Sym,
|
|
const typename ELFT::Verdef *Verdef);
|
|
|
|
template <class ELFT>
|
|
Symbol *addLazyArchive(ArchiveFile *F, const llvm::object::Archive::Symbol S);
|
|
template <class ELFT> void addLazyObject(StringRef Name, LazyObjFile &Obj);
|
|
|
|
Symbol *addBitcode(StringRef Name, uint8_t Binding, uint8_t StOther,
|
|
uint8_t Type, bool CanOmitFromDynSym, BitcodeFile *File);
|
|
|
|
Symbol *addCommon(StringRef N, uint64_t Size, uint32_t Alignment,
|
|
uint8_t Binding, uint8_t StOther, uint8_t Type,
|
|
InputFile *File);
|
|
|
|
std::pair<Symbol *, bool> insert(StringRef Name);
|
|
std::pair<Symbol *, bool> insert(StringRef Name, uint8_t Type,
|
|
uint8_t Visibility, bool CanOmitFromDynSym,
|
|
InputFile *File);
|
|
|
|
template <class ELFT> void scanUndefinedFlags();
|
|
template <class ELFT> void scanShlibUndefined();
|
|
void scanVersionScript();
|
|
|
|
SymbolBody *find(StringRef Name);
|
|
|
|
void trace(StringRef Name);
|
|
|
|
private:
|
|
std::vector<SymbolBody *> findByVersion(SymbolVersion Ver);
|
|
std::vector<SymbolBody *> findAllByVersion(SymbolVersion Ver);
|
|
|
|
llvm::StringMap<std::vector<SymbolBody *>> &getDemangledSyms();
|
|
void handleAnonymousVersion();
|
|
void assignExactVersion(SymbolVersion Ver, uint16_t VersionId,
|
|
StringRef VersionName);
|
|
void assignWildcardVersion(SymbolVersion Ver, uint16_t VersionId);
|
|
|
|
struct SymIndex {
|
|
SymIndex(int Idx, bool Traced) : Idx(Idx), Traced(Traced) {}
|
|
int Idx : 31;
|
|
unsigned Traced : 1;
|
|
};
|
|
|
|
// The order the global symbols are in is not defined. We can use an arbitrary
|
|
// order, but it has to be reproducible. That is true even when cross linking.
|
|
// The default hashing of StringRef produces different results on 32 and 64
|
|
// bit systems so we use a map to a vector. That is arbitrary, deterministic
|
|
// but a bit inefficient.
|
|
// FIXME: Experiment with passing in a custom hashing or sorting the symbols
|
|
// once symbol resolution is finished.
|
|
llvm::DenseMap<llvm::CachedHashStringRef, SymIndex> Symtab;
|
|
std::vector<Symbol *> SymVector;
|
|
|
|
// Comdat groups define "link once" sections. If two comdat groups have the
|
|
// same name, only one of them is linked, and the other is ignored. This set
|
|
// is used to uniquify them.
|
|
llvm::DenseSet<llvm::CachedHashStringRef> ComdatGroups;
|
|
|
|
// Set of .so files to not link the same shared object file more than once.
|
|
llvm::DenseSet<StringRef> SoNames;
|
|
|
|
// A map from demangled symbol names to their symbol objects.
|
|
// This mapping is 1:N because two symbols with different versions
|
|
// can have the same name. We use this map to handle "extern C++ {}"
|
|
// directive in version scripts.
|
|
llvm::Optional<llvm::StringMap<std::vector<SymbolBody *>>> DemangledSyms;
|
|
|
|
// For LTO.
|
|
std::unique_ptr<BitcodeCompiler> LTO;
|
|
};
|
|
|
|
extern SymbolTable *Symtab;
|
|
} // namespace elf
|
|
} // namespace lld
|
|
|
|
#endif
|