X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FMC%2FMCSymbol.h;h=078f3d77e55cd04ca19074e164bf68610677dee3;hb=d99ce2f6305eb090d47188bb041c960413fc3aa1;hp=325afec9feeaed1b537147d37fb2d019fd8a0f78;hpb=63e7baf8f66e94e57c1b8add29edeed9ff63bf38;p=oota-llvm.git diff --git a/include/llvm/MC/MCSymbol.h b/include/llvm/MC/MCSymbol.h index 325afec9fee..078f3d77e55 100644 --- a/include/llvm/MC/MCSymbol.h +++ b/include/llvm/MC/MCSymbol.h @@ -14,12 +14,14 @@ #ifndef LLVM_MC_MCSYMBOL_H #define LLVM_MC_MCSYMBOL_H -#include "llvm/ADT/PointerIntPair.h" +#include "llvm/ADT/PointerUnion.h" #include "llvm/ADT/StringMap.h" +#include "llvm/MC/MCAssembler.h" #include "llvm/MC/MCExpr.h" #include "llvm/Support/Compiler.h" namespace llvm { +class MCAsmInfo; class MCExpr; class MCSymbol; class MCFragment; @@ -35,6 +37,16 @@ class raw_ostream; /// 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 { +protected: + /// The kind of the symbol. If it is any value other than unset then this + /// class is actually one of the appropriate subclasses of MCSymbol. + enum SymbolKind { + SymbolKindUnset, + SymbolKindCOFF, + SymbolKindELF, + SymbolKindMachO, + }; + // Special sentinal value for the absolute pseudo section. // // FIXME: Use a PointerInt wrapper for this? @@ -44,10 +56,18 @@ class MCSymbol { /// held by the StringMap that lives in MCContext. const StringMapEntry *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; + /// If a symbol has a Fragment, the section is implied, so we only need + /// one pointer. + /// FIXME: We might be able to simplify this by having the asm streamer create + /// dummy fragments. + /// If this is a section, then it gives 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. + /// + /// If this is a fragment, then it gives the fragment this symbol's value is + /// relative to, if any. + mutable PointerUnion SectionOrFragment; /// Value - If non-null, the value for a variable symbol. const MCExpr *Value; @@ -63,19 +83,20 @@ class MCSymbol { /// IsUsed - True if this symbol has been used. mutable unsigned IsUsed : 1; - mutable bool HasData : 1; + mutable bool IsRegistered : 1; - /// Index field, for use by the object file implementation. - mutable uint64_t Index : 60; + /// This symbol is visible outside this translation unit. + mutable unsigned IsExternal : 1; - /// 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; + /// This symbol is private extern. + mutable unsigned IsPrivateExtern : 1; - /// The alignment of the symbol, if it is 'common', or -1. - // - // FIXME: Pack this in with other fields? - unsigned CommonAlign = -1U; + /// LLVM RTTI discriminator. This is actually a SymbolKind enumerator, but is + /// unsigned to avoid sign extension and achieve better bitpacking with MSVC. + unsigned Kind : 2; + + /// Index field, for use by the object file implementation. + mutable uint32_t Index = 0; union { /// The offset to apply to the fragment address to form this symbol's value. @@ -85,46 +106,45 @@ class MCSymbol { uint64_t CommonSize; }; + /// The alignment of the symbol, if it is 'common', or -1. + // + // FIXME: Pack this in with other fields? + unsigned CommonAlign = -1U; + /// The Flags field is used by object file implementations to store /// additional per symbol information which is not easily classified. mutable uint32_t Flags = 0; - /// 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). - mutable PointerIntPair Fragment; - -private: // MCContext creates and uniques these. +protected: // MCContext creates and uniques these. friend class MCExpr; friend class MCContext; - MCSymbol(const StringMapEntry *Name, bool isTemporary) - : Name(Name), Section(nullptr), Value(nullptr), IsTemporary(isTemporary), - IsRedefinable(false), IsUsed(false), HasData(false), Index(0) { + MCSymbol(SymbolKind Kind, const StringMapEntry *Name, bool isTemporary) + : Name(Name), Value(nullptr), IsTemporary(isTemporary), + IsRedefinable(false), IsUsed(false), IsRegistered(false), + IsExternal(false), IsPrivateExtern(false), + Kind(Kind) { Offset = 0; } +private: MCSymbol(const MCSymbol &) = delete; void operator=(const MCSymbol &) = delete; MCSection *getSectionPtr() const { + if (MCFragment *F = getFragment()) + return F->getParent(); + assert(!SectionOrFragment.is() && "Section or null expected"); + MCSection *Section = SectionOrFragment.dyn_cast(); if (Section || !Value) return Section; - return Section = Value->FindAssociatedSection(); + return Section = Value->findAssociatedSection(); } public: /// getName - Get the symbol name. StringRef getName() const { return Name ? Name->first() : ""; } - bool hasData() const { return HasData; } - - MCSymbol &getData() const { return *const_cast(this); } - - /// 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; } + bool isRegistered() const { return IsRegistered; } + void setIsRegistered(bool Value) const { IsRegistered = Value; } /// \name Accessors /// @{ @@ -144,7 +164,7 @@ public: void redefineIfPossible() { if (IsRedefinable) { Value = nullptr; - Section = nullptr; + SectionOrFragment = nullptr; IsRedefinable = false; } } @@ -177,11 +197,20 @@ public: /// Mark the symbol as defined in the section \p S. void setSection(MCSection &S) { assert(!isVariable() && "Cannot set section of variable"); - Section = &S; + assert(!SectionOrFragment.is() && "Section or null expected"); + SectionOrFragment = &S; } - /// setUndefined - Mark the symbol as undefined. - void setUndefined() { Section = nullptr; } + /// Mark the symbol as undefined. + void setUndefined() { + SectionOrFragment = nullptr; + } + + bool isELF() const { return Kind == SymbolKindELF; } + + bool isCOFF() const { return Kind == SymbolKindCOFF; } + + bool isMachO() const { return Kind == SymbolKindMachO; } /// @} /// \name Variable Symbols @@ -202,22 +231,15 @@ public: /// @} /// Get the (implementation defined) index. - uint64_t getIndex() const { - assert(HasData && "Uninitialized symbol data"); + uint32_t getIndex() const { 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"); + void setIndex(uint32_t Value) const { Index = Value; } - void setSize(const MCExpr *SS) { SymbolSize = SS; } - - const MCExpr *getSize() const { return SymbolSize; } - uint64_t getOffset() const { assert(!isCommon()); return Offset; @@ -249,9 +271,44 @@ public: return CommonAlign; } + /// 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 || CommonAlign != Align) + return true; + } else + setCommon(Size, Align); + return false; + } + /// Is this a 'common' symbol. bool isCommon() const { return CommonAlign != -1U; } + MCFragment *getFragment() const { + return SectionOrFragment.dyn_cast(); + } + void setFragment(MCFragment *Value) const { + SectionOrFragment = 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; } @@ -262,31 +319,10 @@ public: void modifyFlags(uint32_t Value, uint32_t Mask) const { Flags = (Flags & ~Mask) | Value; } - - MCFragment *getFragment() const { return Fragment.getPointer(); } - void setFragment(MCFragment *Value) const { Fragment.setPointer(Value); } - - bool isExternal() const { return Fragment.getInt() & 1; } - void setExternal(bool Value) const { - 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)); - } - - /// print - Print the value to the stream \p OS. - void print(raw_ostream &OS) const; - - /// dump - Print the value to stderr. - void dump() const; }; -typedef MCSymbol MCSymbolData; - inline raw_ostream &operator<<(raw_ostream &OS, const MCSymbol &Sym) { - Sym.print(OS); + Sym.print(OS, nullptr); return OS; } } // end namespace llvm