diff options
Diffstat (limited to 'include/llvm/MC/MCSymbol.h')
-rw-r--r-- | include/llvm/MC/MCSymbol.h | 404 |
1 files changed, 267 insertions, 137 deletions
diff --git a/include/llvm/MC/MCSymbol.h b/include/llvm/MC/MCSymbol.h index 47a8789d463b..cf99c919281e 100644 --- a/include/llvm/MC/MCSymbol.h +++ b/include/llvm/MC/MCSymbol.h @@ -14,168 +14,298 @@ #ifndef LLVM_MC_MCSYMBOL_H #define LLVM_MC_MCSYMBOL_H -#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/PointerIntPair.h" +#include "llvm/ADT/StringMap.h" +#include "llvm/MC/MCExpr.h" #include "llvm/Support/Compiler.h" namespace llvm { - class MCExpr; - class MCSection; - class MCContext; - class raw_ostream; - - /// MCSymbol - Instances of this class represent a symbol name in the MC file, - /// and MCSymbols are created and unique'd by the MCContext class. MCSymbols - /// should only be constructed with valid names for the object file. +class MCExpr; +class MCSymbol; +class MCFragment; +class MCSection; +class MCContext; +class raw_ostream; + +// TODO: Merge completely with MCSymbol. +class MCSymbolData { + /// Fragment - The fragment this symbol's value is relative to, if any. Also + /// stores if this symbol is visible outside this translation unit (bit 0) or + /// if it is private extern (bit 1). + PointerIntPair<MCFragment *, 2> Fragment; + + union { + /// Offset - The offset to apply to the fragment address to form this + /// symbol's value. + uint64_t Offset; + + /// CommonSize - The size of the symbol, if it is 'common'. + uint64_t CommonSize; + }; + + /// SymbolSize - An expression describing how to calculate the size of + /// a symbol. If a symbol has no size this field will be NULL. + const MCExpr *SymbolSize = nullptr; + + /// CommonAlign - The alignment of the symbol, if it is 'common', or -1. + // + // FIXME: Pack this in with other fields? + unsigned CommonAlign = -1U; + + /// Flags - The Flags field is used by object file implementations to store + /// additional per symbol information which is not easily classified. + uint32_t Flags = 0; + +public: + MCSymbolData() { Offset = 0; } + + MCFragment *getFragment() const { return Fragment.getPointer(); } + void setFragment(MCFragment *Value) { Fragment.setPointer(Value); } + + uint64_t getOffset() const { + assert(!isCommon()); + return Offset; + } + void setOffset(uint64_t Value) { + assert(!isCommon()); + Offset = Value; + } + + /// @} + /// \name Symbol Attributes + /// @{ + + bool isExternal() const { return Fragment.getInt() & 1; } + void setExternal(bool Value) { + Fragment.setInt((Fragment.getInt() & ~1) | unsigned(Value)); + } + + bool isPrivateExtern() const { return Fragment.getInt() & 2; } + void setPrivateExtern(bool Value) { + Fragment.setInt((Fragment.getInt() & ~2) | (unsigned(Value) << 1)); + } + + /// isCommon - Is this a 'common' symbol. + bool isCommon() const { return CommonAlign != -1U; } + + /// setCommon - Mark this symbol as being 'common'. /// - /// If the symbol is defined/emitted into the current translation unit, the - /// Section member is set to indicate what section it lives in. Otherwise, if - /// it is a reference to an external entity, it has a null section. - class MCSymbol { - // Special sentinal value for the absolute pseudo section. - // - // FIXME: Use a PointerInt wrapper for this? - static const MCSection *AbsolutePseudoSection; - - /// Name - The name of the symbol. The referred-to string data is actually - /// held by the StringMap that lives in MCContext. - StringRef Name; - - /// Section - The section the symbol is defined in. This is null for - /// undefined symbols, and the special AbsolutePseudoSection value for - /// absolute symbols. - const MCSection *Section; - - /// Value - If non-null, the value for a variable symbol. - const MCExpr *Value; - - /// IsTemporary - True if this is an assembler temporary label, which - /// typically does not survive in the .o file's symbol table. Usually - /// "Lfoo" or ".foo". - unsigned IsTemporary : 1; - - /// \brief True if this symbol can be redefined. - unsigned IsRedefinable : 1; - - /// IsUsed - True if this symbol has been used. - mutable unsigned IsUsed : 1; - - private: // MCContext creates and uniques these. - friend class MCExpr; - friend class MCContext; - MCSymbol(StringRef name, bool isTemporary) - : Name(name), Section(nullptr), Value(nullptr), - IsTemporary(isTemporary), IsRedefinable(false), IsUsed(false) {} - - MCSymbol(const MCSymbol&) LLVM_DELETED_FUNCTION; - void operator=(const MCSymbol&) LLVM_DELETED_FUNCTION; - public: - /// getName - Get the symbol name. - StringRef getName() const { return Name; } - - /// @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) { - Value = nullptr; - Section = nullptr; - IsRedefinable = false; - } - } + /// \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; + CommonAlign = Align; + } - /// @} - /// @name Associated Sections - /// @{ + /// getCommonSize - Return the size of a 'common' symbol. + uint64_t getCommonSize() const { + assert(isCommon() && "Not a 'common' symbol!"); + return CommonSize; + } - /// 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 Section != nullptr; - } + void setSize(const MCExpr *SS) { SymbolSize = SS; } - /// isInSection - Check if this symbol is defined in some section (i.e., it - /// is defined but not absolute). - bool isInSection() const { - return isDefined() && !isAbsolute(); - } + const MCExpr *getSize() const { return SymbolSize; } - /// isUndefined - Check if this symbol undefined (i.e., implicitly defined). - bool isUndefined() const { - return !isDefined(); - } + /// getCommonAlignment - Return the alignment of a 'common' symbol. + unsigned getCommonAlignment() const { + assert(isCommon() && "Not a 'common' symbol!"); + return CommonAlign; + } - /// isAbsolute - Check if this is an absolute symbol. - bool isAbsolute() const { - return Section == AbsolutePseudoSection; - } + /// getFlags - Get the (implementation defined) symbol flags. + uint32_t getFlags() const { return Flags; } - /// getSection - Get the section associated with a defined, non-absolute - /// symbol. - const MCSection &getSection() const { - assert(isInSection() && "Invalid accessor!"); - return *Section; - } + /// setFlags - Set the (implementation defined) symbol flags. + void setFlags(uint32_t Value) { Flags = Value; } - /// setSection - Mark the symbol as defined in the section \p S. - void setSection(const MCSection &S) { Section = &S; } + /// modifyFlags - Modify the flags via a mask + void modifyFlags(uint32_t Value, uint32_t Mask) { + Flags = (Flags & ~Mask) | Value; + } + + /// @} + + void dump() const; +}; + +/// MCSymbol - Instances of this class represent a symbol name in the MC file, +/// and MCSymbols are created and uniqued by the MCContext class. MCSymbols +/// should only be constructed with valid names for the object file. +/// +/// If the symbol is defined/emitted into the current translation unit, the +/// Section member is set to indicate what section it lives in. Otherwise, if +/// it is a reference to an external entity, it has a null section. +class MCSymbol { + // Special sentinal value for the absolute pseudo section. + // + // FIXME: Use a PointerInt wrapper for this? + static MCSection *AbsolutePseudoSection; + + /// Name - The name of the symbol. The referred-to string data is actually + /// held by the StringMap that lives in MCContext. + const StringMapEntry<bool> *Name; + + /// The section the symbol is defined in. This is null for undefined symbols, + /// and the special AbsolutePseudoSection value for absolute symbols. If this + /// is a variable symbol, this caches the variable value's section. + mutable MCSection *Section; + + /// Value - If non-null, the value for a variable symbol. + const MCExpr *Value; + + /// IsTemporary - True if this is an assembler temporary label, which + /// typically does not survive in the .o file's symbol table. Usually + /// "Lfoo" or ".foo". + unsigned IsTemporary : 1; + + /// \brief True if this symbol can be redefined. + unsigned IsRedefinable : 1; + + /// IsUsed - True if this symbol has been used. + mutable unsigned IsUsed : 1; + + mutable bool HasData : 1; + + /// Index field, for use by the object file implementation. + mutable uint64_t Index : 60; + + mutable MCSymbolData Data; + +private: // MCContext creates and uniques these. + friend class MCExpr; + friend class MCContext; + MCSymbol(const StringMapEntry<bool> *Name, bool isTemporary) + : Name(Name), Section(nullptr), Value(nullptr), IsTemporary(isTemporary), + IsRedefinable(false), IsUsed(false), HasData(false), Index(0) {} + + MCSymbol(const MCSymbol &) = delete; + void operator=(const MCSymbol &) = delete; + MCSection *getSectionPtr() const { + if (Section || !Value) + return Section; + return Section = Value->FindAssociatedSection(); + } + +public: + /// getName - Get the symbol name. + StringRef getName() const { return Name ? Name->first() : ""; } + + bool hasData() const { return HasData; } + + /// Get associated symbol data. + MCSymbolData &getData() const { + assert(HasData && "Missing symbol data!"); + return Data; + } - /// setUndefined - Mark the symbol as undefined. - void setUndefined() { + /// Initialize symbol data. + /// + /// Nothing really to do here, but this is enables an assertion that \a + /// MCAssembler::getOrCreateSymbolData() has actually been called before + /// anyone calls \a getData(). + void initializeData() const { HasData = true; } + + /// \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) { + Value = nullptr; Section = nullptr; + IsRedefinable = false; } + } - /// setAbsolute - Mark the symbol as absolute. - void setAbsolute() { Section = AbsolutePseudoSection; } + /// @} + /// \name Associated Sections + /// @{ - /// @} - /// @name Variable Symbols - /// @{ + /// 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; } - /// isVariable - Check if this is a variable symbol. - bool isVariable() const { - return Value != 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(); } - /// getVariableValue() - Get the value for variable symbols. - const MCExpr *getVariableValue() const { - assert(isVariable() && "Invalid accessor!"); - IsUsed = true; - return Value; - } + /// isUndefined - Check if this symbol undefined (i.e., implicitly defined). + bool isUndefined() const { return !isDefined(); } - // AliasedSymbol() - If this is an alias (a = b), return the symbol - // we ultimately point to. For a non-alias, this just returns the symbol - // itself. - const MCSymbol &AliasedSymbol() const; + /// isAbsolute - Check if this is an absolute symbol. + bool isAbsolute() const { return getSectionPtr() == AbsolutePseudoSection; } - void setVariableValue(const MCExpr *Value); + /// 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"); + Section = &S; + } - /// print - Print the value to the stream \p OS. - void print(raw_ostream &OS) const; + /// setUndefined - Mark the symbol as undefined. + void setUndefined() { Section = nullptr; } - /// dump - Print the value to stderr. - void dump() const; - }; + /// @} + /// \name Variable Symbols + /// @{ + + /// isVariable - Check if this is a variable symbol. + bool isVariable() const { return Value != nullptr; } + + /// getVariableValue() - Get the value for variable symbols. + const MCExpr *getVariableValue() const { + assert(isVariable() && "Invalid accessor!"); + IsUsed = true; + return Value; + } + + void setVariableValue(const MCExpr *Value); - inline raw_ostream &operator<<(raw_ostream &OS, const MCSymbol &Sym) { - Sym.print(OS); - return OS; + /// @} + + /// Get the (implementation defined) index. + uint64_t getIndex() const { + assert(HasData && "Uninitialized symbol data"); + return Index; + } + + /// Set the (implementation defined) index. + void setIndex(uint64_t Value) const { + assert(HasData && "Uninitialized symbol data"); + assert(!(Value >> 60) && "Not enough bits for value"); + Index = Value; } + + /// print - Print the value to the stream \p OS. + void print(raw_ostream &OS) const; + + /// dump - Print the value to stderr. + void dump() const; +}; + +inline raw_ostream &operator<<(raw_ostream &OS, const MCSymbol &Sym) { + Sym.print(OS); + return OS; +} } // end namespace llvm #endif |