+protected: // MCContext creates and uniques these.
+ friend class MCExpr;
+ friend class MCContext;
+
+ /// \brief The name for a symbol.
+ /// MCSymbol contains a uint64_t so is probably aligned to 8. On a 32-bit
+ /// system, the name is a pointer so isn't going to satisfy the 8 byte
+ /// alignment of uint64_t. Account for that here.
+ typedef union {
+ const StringMapEntry<bool> *NameEntry;
+ uint64_t AlignmentPadding;
+ } NameEntryStorageTy;
+
+ MCSymbol(SymbolKind Kind, const StringMapEntry<bool> *Name, bool isTemporary)
+ : IsTemporary(isTemporary), IsRedefinable(false), IsUsed(false),
+ IsRegistered(false), IsExternal(false), IsPrivateExtern(false),
+ Kind(Kind), IsUsedInReloc(false), SymbolContents(SymContentsUnset),
+ CommonAlignLog2(0), Flags(0) {
+ Offset = 0;
+ SectionOrFragmentAndHasName.setInt(!!Name);
+ if (Name)
+ getNameEntryPtr() = Name;
+ }
+
+ // Provide custom new/delete as we will only allocate space for a name
+ // if we need one.
+ void *operator new(size_t s, const StringMapEntry<bool> *Name,
+ MCContext &Ctx);
+
+private:
+
+ void operator delete(void *);
+ /// \brief Placement delete - required by std, but never called.
+ void operator delete(void*, unsigned) {
+ llvm_unreachable("Constructor throws?");
+ }
+ /// \brief Placement delete - required by std, but never called.
+ void operator delete(void*, unsigned, bool) {
+ llvm_unreachable("Constructor throws?");
+ }
+
+ MCSymbol(const MCSymbol &) = delete;
+ void operator=(const MCSymbol &) = delete;
+ MCSection *getSectionPtr() const {
+ if (MCFragment *F = getFragment())
+ return F->getParent();
+ const auto &SectionOrFragment = SectionOrFragmentAndHasName.getPointer();
+ assert(!SectionOrFragment.is<MCFragment *>() && "Section or null expected");
+ MCSection *Section = SectionOrFragment.dyn_cast<MCSection *>();
+ if (Section || !isVariable())
+ return Section;
+ return Section = getVariableValue()->findAssociatedSection();
+ }
+
+ /// \brief Get a reference to the name field. Requires that we have a name
+ const StringMapEntry<bool> *&getNameEntryPtr() {
+ assert(SectionOrFragmentAndHasName.getInt() && "Name is required");
+ NameEntryStorageTy *Name = reinterpret_cast<NameEntryStorageTy *>(this);
+ return (*(Name - 1)).NameEntry;
+ }
+ const StringMapEntry<bool> *&getNameEntryPtr() const {
+ return const_cast<MCSymbol*>(this)->getNameEntryPtr();
+ }
+
+public:
+ /// getName - Get the symbol name.
+ StringRef getName() const {
+ if (!SectionOrFragmentAndHasName.getInt())
+ return StringRef();
+
+ return getNameEntryPtr()->first();
+ }
+
+ bool isRegistered() const { return IsRegistered; }
+ void setIsRegistered(bool Value) const { IsRegistered = Value; }
+
+ void setUsedInReloc() const { IsUsedInReloc = true; }
+ bool isUsedInReloc() const { return IsUsedInReloc; }
+
+ /// \name Accessors
+ /// @{
+
+ /// isTemporary - Check if this is an assembler temporary symbol.
+ bool isTemporary() const { return IsTemporary; }
+
+ /// isUsed - Check if this is used.
+ bool isUsed() const { return IsUsed; }
+ void setUsed(bool Value) const { IsUsed = Value; }
+
+ /// \brief Check if this symbol is redefinable.
+ bool isRedefinable() const { return IsRedefinable; }
+ /// \brief Mark this symbol as redefinable.
+ void setRedefinable(bool Value) { IsRedefinable = Value; }
+ /// \brief Prepare this symbol to be redefined.
+ void redefineIfPossible() {
+ if (IsRedefinable) {
+ if (SymbolContents == SymContentsVariable) {
+ Value = nullptr;
+ SymbolContents = SymContentsUnset;
+ }
+ setUndefined();
+ IsRedefinable = false;
+ }
+ }
+
+ /// @}
+ /// \name Associated Sections
+ /// @{
+
+ /// isDefined - Check if this symbol is defined (i.e., it has an address).
+ ///
+ /// Defined symbols are either absolute or in some section.
+ bool isDefined() const { return getSectionPtr() != nullptr; }
+
+ /// isInSection - Check if this symbol is defined in some section (i.e., it
+ /// is defined but not absolute).
+ bool isInSection() const { return isDefined() && !isAbsolute(); }
+
+ /// isUndefined - Check if this symbol undefined (i.e., implicitly defined).
+ bool isUndefined() const { return !isDefined(); }
+
+ /// isAbsolute - Check if this is an absolute symbol.
+ bool isAbsolute() const { return getSectionPtr() == AbsolutePseudoSection; }
+
+ /// Get the section associated with a defined, non-absolute symbol.
+ MCSection &getSection() const {
+ assert(isInSection() && "Invalid accessor!");
+ return *getSectionPtr();
+ }
+
+ /// Mark the symbol as defined in the section \p S.
+ void setSection(MCSection &S) {
+ assert(!isVariable() && "Cannot set section of variable");
+ assert(!SectionOrFragmentAndHasName.getPointer().is<MCFragment *>() &&
+ "Section or null expected");
+ SectionOrFragmentAndHasName.setPointer(&S);
+ }
+
+ /// Mark the symbol as undefined.
+ void setUndefined() {
+ SectionOrFragmentAndHasName.setPointer(
+ PointerUnion<MCSection *, MCFragment *>());
+ }
+
+ bool isELF() const { return Kind == SymbolKindELF; }
+
+ bool isCOFF() const { return Kind == SymbolKindCOFF; }
+
+ bool isMachO() const { return Kind == SymbolKindMachO; }
+
+ /// @}
+ /// \name Variable Symbols
+ /// @{
+
+ /// isVariable - Check if this is a variable symbol.
+ bool isVariable() const {
+ return SymbolContents == SymContentsVariable;
+ }
+
+ /// getVariableValue() - Get the value for variable symbols.
+ const MCExpr *getVariableValue() const {
+ assert(isVariable() && "Invalid accessor!");
+ IsUsed = true;
+ return Value;
+ }
+
+ void setVariableValue(const MCExpr *Value);
+
+ /// @}
+
+ /// Get the (implementation defined) index.
+ uint32_t getIndex() const {
+ return Index;
+ }
+
+ /// Set the (implementation defined) index.
+ void setIndex(uint32_t Value) const {
+ Index = Value;
+ }
+
+ uint64_t getOffset() const {
+ assert((SymbolContents == SymContentsUnset ||
+ SymbolContents == SymContentsOffset) &&
+ "Cannot get offset for a common/variable symbol");
+ return Offset;
+ }
+ void setOffset(uint64_t Value) {
+ assert((SymbolContents == SymContentsUnset ||
+ SymbolContents == SymContentsOffset) &&
+ "Cannot set offset for a common/variable symbol");
+ Offset = Value;
+ SymbolContents = SymContentsOffset;
+ }
+
+ /// Return the size of a 'common' symbol.
+ uint64_t getCommonSize() const {
+ assert(isCommon() && "Not a 'common' symbol!");
+ return CommonSize;
+ }
+
+ /// Mark this symbol as being 'common'.
+ ///
+ /// \param Size - The size of the symbol.
+ /// \param Align - The alignment of the symbol.
+ void setCommon(uint64_t Size, unsigned Align) {
+ assert(getOffset() == 0);
+ CommonSize = Size;
+ SymbolContents = SymContentsCommon;
+
+ assert((!Align || isPowerOf2_32(Align)) &&
+ "Alignment must be a power of 2");
+ unsigned Log2Align = Log2_32(Align) + 1;
+ assert(Log2Align < (1U << NumCommonAlignmentBits) &&
+ "Out of range alignment");
+ CommonAlignLog2 = Log2Align;
+ }
+
+ /// Return the alignment of a 'common' symbol.
+ unsigned getCommonAlignment() const {
+ assert(isCommon() && "Not a 'common' symbol!");
+ return CommonAlignLog2 ? (1U << (CommonAlignLog2 - 1)) : 0;
+ }
+
+ /// Declare this symbol as being 'common'.
+ ///
+ /// \param Size - The size of the symbol.
+ /// \param Align - The alignment of the symbol.
+ /// \return True if symbol was already declared as a different type
+ bool declareCommon(uint64_t Size, unsigned Align) {
+ assert(isCommon() || getOffset() == 0);
+ if(isCommon()) {
+ if(CommonSize != Size || getCommonAlignment() != Align)
+ return true;
+ } else
+ setCommon(Size, Align);
+ return false;
+ }
+
+ /// Is this a 'common' symbol.
+ bool isCommon() const {
+ return SymbolContents == SymContentsCommon;
+ }
+
+ MCFragment *getFragment() const {
+ return SectionOrFragmentAndHasName.getPointer().dyn_cast<MCFragment *>();
+ }
+ void setFragment(MCFragment *Value) const {
+ SectionOrFragmentAndHasName.setPointer(Value);
+ }
+
+ bool isExternal() const { return IsExternal; }
+ void setExternal(bool Value) const { IsExternal = Value; }
+
+ bool isPrivateExtern() const { return IsPrivateExtern; }
+ void setPrivateExtern(bool Value) { IsPrivateExtern = Value; }
+
+ /// print - Print the value to the stream \p OS.
+ void print(raw_ostream &OS, const MCAsmInfo *MAI) const;
+
+ /// dump - Print the value to stderr.
+ void dump() const;
+
+protected:
+ /// Get the (implementation defined) symbol flags.
+ uint32_t getFlags() const { return Flags; }
+
+ /// Set the (implementation defined) symbol flags.
+ void setFlags(uint32_t Value) const {
+ assert(Value < (1U << NumFlagsBits) && "Out of range flags");
+ Flags = Value;
+ }
+
+ /// Modify the flags via a mask
+ void modifyFlags(uint32_t Value, uint32_t Mask) const {
+ assert(Value < (1U << NumFlagsBits) && "Out of range flags");
+ Flags = (Flags & ~Mask) | Value;
+ }
+};
+
+inline raw_ostream &operator<<(raw_ostream &OS, const MCSymbol &Sym) {
+ Sym.print(OS, nullptr);
+ return OS;
+}