#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
-#include "llvm/MC/MCELFSymbolFlags.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCObjectWriter.h"
static uint64_t SymbolValue(const MCSymbol &Sym, const MCAsmLayout &Layout);
static bool isInSymtab(const MCAsmLayout &Layout, const MCSymbolELF &Symbol,
bool Used, bool Renamed);
- static bool isLocal(const MCSymbol &Symbol, bool IsUsedInReloc,
- bool IsSignature);
/// Helper struct for containing some precomputed information on symbols.
struct ELFSymbolData {
/// The target specific ELF writer instance.
std::unique_ptr<MCELFObjectTargetWriter> TargetObjectWriter;
- SmallPtrSet<const MCSymbol *, 16> UsedInReloc;
- SmallPtrSet<const MCSymbol *, 16> WeakrefUsedInReloc;
DenseMap<const MCSymbolELF *, const MCSymbolELF *> Renames;
llvm::DenseMap<const MCSectionELF *, std::vector<ELFRelocationEntry>>
: MCObjectWriter(OS, IsLittleEndian), TargetObjectWriter(MOTW) {}
void reset() override {
- UsedInReloc.clear();
- WeakrefUsedInReloc.clear();
Renames.clear();
Relocations.clear();
StrTabBuilder.clear();
void ExecutePostLayoutBinding(MCAssembler &Asm,
const MCAsmLayout &Layout) override;
- void writeSectionHeader(const MCAssembler &Asm, const MCAsmLayout &Layout,
+ void writeSectionHeader(const MCAsmLayout &Layout,
const SectionIndexMapTy &SectionIndexMap,
const SectionOffsetsTy &SectionOffsets);
if (Base) {
Type = mergeTypeForSet(Type, Base->getType());
}
- uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift);
+ uint8_t Info = (Binding << 4) | Type;
// Other and Visibility share the same byte with Visibility using the lower
// 2 bits
uint8_t Visibility = Symbol.getVisibility();
- uint8_t Other = Symbol.getOther() << (ELF_STO_Shift - ELF_STV_Shift);
- Other |= Visibility;
+ uint8_t Other = Symbol.getOther() | Visibility;
uint64_t Value = SymbolValue(*MSD.Symbol, Layout);
uint64_t Size = 0;
return false;
}
-static const MCSymbol *getWeakRef(const MCSymbolRefExpr &Ref) {
- const MCSymbol &Sym = Ref.getSymbol();
-
- if (Ref.getKind() == MCSymbolRefExpr::VK_WEAKREF)
- return &Sym;
-
- if (!Sym.isVariable())
- return nullptr;
-
- const MCExpr *Expr = Sym.getVariableValue();
- const auto *Inner = dyn_cast<MCSymbolRefExpr>(Expr);
- if (!Inner)
- return nullptr;
-
- if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF)
- return &Inner->getSymbol();
- return nullptr;
-}
-
// True if the assembler knows nothing about the final value of the symbol.
// This doesn't cover the comdat issues, since in those cases the assembler
// can at least know that all symbols in the section will move together.
const MCSymbolRefExpr *RefA = Target.getSymA();
const auto *SymA = RefA ? cast<MCSymbolELF>(&RefA->getSymbol()) : nullptr;
+ bool ViaWeakRef = false;
+ if (SymA && SymA->isVariable()) {
+ const MCExpr *Expr = SymA->getVariableValue();
+ if (const auto *Inner = dyn_cast<MCSymbolRefExpr>(Expr)) {
+ if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF) {
+ SymA = cast<MCSymbolELF>(&Inner->getSymbol());
+ ViaWeakRef = true;
+ }
+ }
+ }
+
unsigned Type = GetRelocType(Target, Fixup, IsPCRel);
bool RelocateWithSymbol = shouldRelocateWithSymbol(Asm, RefA, SymA, C, Type);
if (!RelocateWithSymbol && SymA && !SymA->isUndefined())
auto *ELFSec = cast_or_null<MCSectionELF>(SecA);
const auto *SectionSymbol =
ELFSec ? cast<MCSymbolELF>(ELFSec->getBeginSymbol()) : nullptr;
+ if (SectionSymbol)
+ SectionSymbol->setUsedInReloc();
ELFRelocationEntry Rec(FixupOffset, SectionSymbol, Type, Addend);
Relocations[&FixupSection].push_back(Rec);
return;
if (const MCSymbolELF *R = Renames.lookup(SymA))
SymA = R;
- if (const MCSymbol *WeakRef = getWeakRef(*RefA))
- WeakrefUsedInReloc.insert(WeakRef);
+ if (ViaWeakRef)
+ SymA->setIsWeakrefUsedInReloc();
else
- UsedInReloc.insert(SymA);
+ SymA->setUsedInReloc();
}
ELFRelocationEntry Rec(FixupOffset, SymA, Type, Addend);
Relocations[&FixupSection].push_back(Rec);
if (Renamed)
return false;
- if (Symbol.getName() == "_GLOBAL_OFFSET_TABLE_")
- return true;
-
- if (Symbol.isVariable()) {
- const MCSymbol *Base = Layout.getBaseSymbol(Symbol);
- if (Base && Base->isUndefined())
- return false;
+ if (Symbol.isVariable() && Symbol.isUndefined()) {
+ // FIXME: this is here just to diagnose the case of a var = commmon_sym.
+ Layout.getBaseSymbol(Symbol);
+ return false;
}
- bool IsGlobal = Symbol.getBinding() == ELF::STB_GLOBAL;
- if (!Symbol.isVariable() && Symbol.isUndefined() && !IsGlobal)
+ if (Symbol.isUndefined() && !Symbol.isBindingSet())
return false;
- if (Symbol.getType() == ELF::STT_SECTION)
- return true;
-
if (Symbol.isTemporary())
return false;
- return true;
-}
-
-bool ELFObjectWriter::isLocal(const MCSymbol &Symbol, bool IsUsedInReloc,
- bool IsSignature) {
- if (Symbol.isExternal())
- return false;
-
- if (Symbol.isDefined())
- return true;
-
- if (IsUsedInReloc)
+ if (Symbol.getType() == ELF::STT_SECTION)
return false;
- return IsSignature;
+ return true;
}
void ELFObjectWriter::computeSymbolTable(
bool HasLargeSectionIndex = false;
for (const MCSymbol &S : Asm.symbols()) {
const auto &Symbol = cast<MCSymbolELF>(S);
- bool Used = UsedInReloc.count(&Symbol);
- bool WeakrefUsed = WeakrefUsedInReloc.count(&Symbol);
- bool isSignature = RevGroupMap.count(&Symbol);
+ bool Used = Symbol.isUsedInReloc();
+ bool WeakrefUsed = Symbol.isWeakrefUsedInReloc();
+ bool isSignature = Symbol.isSignature();
if (!isInSymtab(Layout, Symbol, Used || WeakrefUsed || isSignature,
Renames.count(&Symbol)))
ELFSymbolData MSD;
MSD.Symbol = cast<MCSymbolELF>(&Symbol);
- // Undefined symbols are global, but this is the first place we
- // are able to set it.
- bool Local = isLocal(Symbol, Used, isSignature);
- if (!Local && Symbol.getBinding() == ELF::STB_LOCAL)
- Symbol.setBinding(ELF::STB_GLOBAL);
-
+ bool Local = Symbol.getBinding() == ELF::STB_LOCAL;
if (Symbol.isAbsolute()) {
MSD.SectionIndex = ELF::SHN_ABS;
} else if (Symbol.isCommon()) {
} else {
MSD.SectionIndex = ELF::SHN_UNDEF;
}
- if (!Used && WeakrefUsed)
- Symbol.setBinding(ELF::STB_WEAK);
} else {
const MCSectionELF &Section =
static_cast<const MCSectionELF &>(Symbol.getSection());
}
void ELFObjectWriter::writeSectionHeader(
- const MCAssembler &Asm, const MCAsmLayout &Layout,
- const SectionIndexMapTy &SectionIndexMap,
+ const MCAsmLayout &Layout, const SectionIndexMapTy &SectionIndexMap,
const SectionOffsetsTy &SectionOffsets) {
const unsigned NumSections = SectionTable.size();
const unsigned SectionHeaderOffset = OS.tell();
// ... then the section header table ...
- writeSectionHeader(Asm, Layout, SectionIndexMap, SectionOffsets);
+ writeSectionHeader(Layout, SectionIndexMap, SectionOffsets);
uint16_t NumSections = (SectionTable.size() + 1 >= ELF::SHN_LORESERVE)
? (uint16_t)ELF::SHN_UNDEF
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