llvm-project/lld/ELF/Symbols.cpp

74 lines
2.1 KiB
C++

//===- Symbols.cpp --------------------------------------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "Symbols.h"
#include "Chunks.h"
#include "Error.h"
#include "InputFiles.h"
using namespace llvm::object;
using namespace llvm::ELF;
using namespace lld;
using namespace lld::elf2;
static uint8_t getMinVisibility(uint8_t VA, uint8_t VB) {
if (VA == STV_DEFAULT)
return VB;
if (VB == STV_DEFAULT)
return VA;
return std::min(VA, VB);
}
// Returns 1, 0 or -1 if this symbol should take precedence
// over the Other, tie or lose, respectively.
template <class ELFT> int SymbolBody::compare(SymbolBody *Other) {
std::pair<bool, bool> L(isDefined(), !isWeak());
std::pair<bool, bool> R(Other->isDefined(), !Other->isWeak());
// Normalize
if (L > R)
return -Other->compare<ELFT>(this);
uint8_t LV = getMostConstrainingVisibility();
uint8_t RV = Other->getMostConstrainingVisibility();
MostConstrainingVisibility = getMinVisibility(LV, RV);
Other->MostConstrainingVisibility = MostConstrainingVisibility;
if (L != R)
return -1;
if (L.first && L.second) {
if (isCommon()) {
if (Other->isCommon()) {
auto *ThisC = cast<DefinedCommon<ELFT>>(this);
auto *OtherC = cast<DefinedCommon<ELFT>>(Other);
typename DefinedCommon<ELFT>::uintX_t MaxAlign =
std::max(ThisC->MaxAlignment, OtherC->MaxAlignment);
if (ThisC->Sym.st_size >= OtherC->Sym.st_size) {
ThisC->MaxAlignment = MaxAlign;
return 1;
}
OtherC->MaxAlignment = MaxAlign;
return -1;
}
return -1;
}
if (Other->isCommon())
return 1;
return 0;
}
return 1;
}
template int SymbolBody::compare<ELF32LE>(SymbolBody *Other);
template int SymbolBody::compare<ELF32BE>(SymbolBody *Other);
template int SymbolBody::compare<ELF64LE>(SymbolBody *Other);
template int SymbolBody::compare<ELF64BE>(SymbolBody *Other);