| //===-- lib/CodeGen/ELF.h - ELF constants and data structures ---*- C++ -*-===// | 
 | // | 
 | //                     The LLVM Compiler Infrastructure | 
 | // | 
 | // This file is distributed under the University of Illinois Open Source | 
 | // License. See LICENSE.TXT for details. | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 | // | 
 | // This header contains common, non-processor-specific data structures and | 
 | // constants for the ELF file format. | 
 | // | 
 | // The details of the ELF32 bits in this file are largely based on the Tool | 
 | // Interface Standard (TIS) Executable and Linking Format (ELF) Specification | 
 | // Version 1.2, May 1995. The ELF64 is based on HP/Intel definition of the | 
 | // ELF-64 object file format document, Version 1.5 Draft 2 May 27, 1998 | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | #ifndef CODEGEN_ELF_H | 
 | #define CODEGEN_ELF_H | 
 |  | 
 | #include "llvm/CodeGen/BinaryObject.h" | 
 | #include "llvm/CodeGen/MachineRelocation.h" | 
 | #include "llvm/Support/ELF.h" | 
 | #include "llvm/Support/DataTypes.h" | 
 |  | 
 | namespace llvm { | 
 |   class GlobalValue; | 
 |  | 
 |   /// ELFSym - This struct contains information about each symbol that is | 
 |   /// added to logical symbol table for the module.  This is eventually | 
 |   /// turned into a real symbol table in the file. | 
 |   struct ELFSym { | 
 |  | 
 |     // ELF symbols are related to llvm ones by being one of the two llvm | 
 |     // types, for the other ones (section, file, func) a null pointer is | 
 |     // assumed by default. | 
 |     union { | 
 |       const GlobalValue *GV;  // If this is a pointer to a GV | 
 |       const char *Ext;        // If this is a pointer to a named symbol | 
 |     } Source; | 
 |  | 
 |     // Describes from which source type this ELF symbol comes from, | 
 |     // they can be GlobalValue, ExternalSymbol or neither. | 
 |     enum { | 
 |       isGV,      // The Source.GV field is valid. | 
 |       isExtSym,  // The Source.ExtSym field is valid. | 
 |       isOther    // Not a GlobalValue or External Symbol | 
 |     }; | 
 |     unsigned SourceType; | 
 |  | 
 |     bool isGlobalValue() const { return SourceType == isGV; } | 
 |     bool isExternalSym() const { return SourceType == isExtSym; } | 
 |  | 
 |     // getGlobalValue - If this is a global value which originated the | 
 |     // elf symbol, return a reference to it. | 
 |     const GlobalValue *getGlobalValue() const { | 
 |       assert(SourceType == isGV && "This is not a global value"); | 
 |       return Source.GV; | 
 |     } | 
 |  | 
 |     // getExternalSym - If this is an external symbol which originated the | 
 |     // elf symbol, return a reference to it. | 
 |     const char *getExternalSymbol() const { | 
 |       assert(SourceType == isExtSym && "This is not an external symbol"); | 
 |       return Source.Ext; | 
 |     } | 
 |  | 
 |     // getGV - From a global value return a elf symbol to represent it | 
 |     static ELFSym *getGV(const GlobalValue *GV, unsigned Bind, | 
 |                          unsigned Type, unsigned Visibility) { | 
 |       ELFSym *Sym = new ELFSym(); | 
 |       Sym->Source.GV = GV; | 
 |       Sym->setBind(Bind); | 
 |       Sym->setType(Type); | 
 |       Sym->setVisibility(Visibility); | 
 |       Sym->SourceType = isGV; | 
 |       return Sym; | 
 |     } | 
 |  | 
 |     // getExtSym - Create and return an elf symbol to represent an | 
 |     // external symbol | 
 |     static ELFSym *getExtSym(const char *Ext) { | 
 |       ELFSym *Sym = new ELFSym(); | 
 |       Sym->Source.Ext = Ext; | 
 |       Sym->setBind(ELF::STB_GLOBAL); | 
 |       Sym->setType(ELF::STT_NOTYPE); | 
 |       Sym->setVisibility(ELF::STV_DEFAULT); | 
 |       Sym->SourceType = isExtSym; | 
 |       return Sym; | 
 |     } | 
 |  | 
 |     // getSectionSym - Returns a elf symbol to represent an elf section | 
 |     static ELFSym *getSectionSym() { | 
 |       ELFSym *Sym = new ELFSym(); | 
 |       Sym->setBind(ELF::STB_LOCAL); | 
 |       Sym->setType(ELF::STT_SECTION); | 
 |       Sym->setVisibility(ELF::STV_DEFAULT); | 
 |       Sym->SourceType = isOther; | 
 |       return Sym; | 
 |     } | 
 |  | 
 |     // getFileSym - Returns a elf symbol to represent the module identifier | 
 |     static ELFSym *getFileSym() { | 
 |       ELFSym *Sym = new ELFSym(); | 
 |       Sym->setBind(ELF::STB_LOCAL); | 
 |       Sym->setType(ELF::STT_FILE); | 
 |       Sym->setVisibility(ELF::STV_DEFAULT); | 
 |       Sym->SectionIdx = 0xfff1;  // ELFSection::SHN_ABS; | 
 |       Sym->SourceType = isOther; | 
 |       return Sym; | 
 |     } | 
 |  | 
 |     // getUndefGV - Returns a STT_NOTYPE symbol | 
 |     static ELFSym *getUndefGV(const GlobalValue *GV, unsigned Bind) { | 
 |       ELFSym *Sym = new ELFSym(); | 
 |       Sym->Source.GV = GV; | 
 |       Sym->setBind(Bind); | 
 |       Sym->setType(ELF::STT_NOTYPE); | 
 |       Sym->setVisibility(ELF::STV_DEFAULT); | 
 |       Sym->SectionIdx = 0;  //ELFSection::SHN_UNDEF; | 
 |       Sym->SourceType = isGV; | 
 |       return Sym; | 
 |     } | 
 |  | 
 |     // ELF specific fields | 
 |     unsigned NameIdx;         // Index in .strtab of name, once emitted. | 
 |     uint64_t Value; | 
 |     unsigned Size; | 
 |     uint8_t Info; | 
 |     uint8_t Other; | 
 |     unsigned short SectionIdx; | 
 |  | 
 |     // Symbol index into the Symbol table | 
 |     unsigned SymTabIdx; | 
 |  | 
 |     ELFSym() : SourceType(isOther), NameIdx(0), Value(0), | 
 |                Size(0), Info(0), Other(ELF::STV_DEFAULT), SectionIdx(0), | 
 |                SymTabIdx(0) {} | 
 |  | 
 |     unsigned getBind() const { return (Info >> 4) & 0xf; } | 
 |     unsigned getType() const { return Info & 0xf; } | 
 |     bool isLocalBind() const { return getBind() == ELF::STB_LOCAL; } | 
 |     bool isFileType() const { return getType() == ELF::STT_FILE; } | 
 |  | 
 |     void setBind(unsigned X) { | 
 |       assert(X == (X & 0xF) && "Bind value out of range!"); | 
 |       Info = (Info & 0x0F) | (X << 4); | 
 |     } | 
 |  | 
 |     void setType(unsigned X) { | 
 |       assert(X == (X & 0xF) && "Type value out of range!"); | 
 |       Info = (Info & 0xF0) | X; | 
 |     } | 
 |  | 
 |     void setVisibility(unsigned V) { | 
 |       assert(V == (V & 0x3) && "Visibility value out of range!"); | 
 |       Other = V; | 
 |     } | 
 |   }; | 
 |  | 
 |   /// ELFSection - This struct contains information about each section that is | 
 |   /// emitted to the file.  This is eventually turned into the section header | 
 |   /// table at the end of the file. | 
 |   class ELFSection : public BinaryObject { | 
 |     public: | 
 |     // ELF specific fields | 
 |     unsigned NameIdx;   // sh_name - .shstrtab idx of name, once emitted. | 
 |     unsigned Type;      // sh_type - Section contents & semantics  | 
 |     unsigned Flags;     // sh_flags - Section flags. | 
 |     uint64_t Addr;      // sh_addr - The mem addr this section is in. | 
 |     unsigned Offset;    // sh_offset - Offset from the file start | 
 |     unsigned Size;      // sh_size - The section size. | 
 |     unsigned Link;      // sh_link - Section header table index link. | 
 |     unsigned Info;      // sh_info - Auxiliary information. | 
 |     unsigned Align;     // sh_addralign - Alignment of section. | 
 |     unsigned EntSize;   // sh_entsize - Size of entries in the section e | 
 |  | 
 |     /// SectionIdx - The number of the section in the Section Table. | 
 |     unsigned short SectionIdx; | 
 |  | 
 |     /// Sym - The symbol to represent this section if it has one. | 
 |     ELFSym *Sym; | 
 |  | 
 |     /// getSymIndex - Returns the symbol table index of the symbol | 
 |     /// representing this section. | 
 |     unsigned getSymbolTableIndex() const { | 
 |       assert(Sym && "section not present in the symbol table"); | 
 |       return Sym->SymTabIdx; | 
 |     } | 
 |  | 
 |     ELFSection(const std::string &name, bool isLittleEndian, bool is64Bit) | 
 |       : BinaryObject(name, isLittleEndian, is64Bit), Type(0), Flags(0), Addr(0), | 
 |         Offset(0), Size(0), Link(0), Info(0), Align(0), EntSize(0), Sym(0) {} | 
 |   }; | 
 |  | 
 |   /// ELFRelocation - This class contains all the information necessary to | 
 |   /// to generate any 32-bit or 64-bit ELF relocation entry. | 
 |   class ELFRelocation { | 
 |     uint64_t r_offset;    // offset in the section of the object this applies to | 
 |     uint32_t r_symidx;    // symbol table index of the symbol to use | 
 |     uint32_t r_type;      // machine specific relocation type | 
 |     int64_t  r_add;       // explicit relocation addend | 
 |     bool     r_rela;      // if true then the addend is part of the entry | 
 |                           // otherwise the addend is at the location specified | 
 |                           // by r_offset | 
 |   public: | 
 |     uint64_t getInfo(bool is64Bit) const { | 
 |       if (is64Bit) | 
 |         return ((uint64_t)r_symidx << 32) + ((uint64_t)r_type & 0xFFFFFFFFL); | 
 |       else | 
 |         return (r_symidx << 8)  + (r_type & 0xFFL); | 
 |     } | 
 |  | 
 |     uint64_t getOffset() const { return r_offset; } | 
 |     int64_t getAddend() const { return r_add; } | 
 |  | 
 |     ELFRelocation(uint64_t off, uint32_t sym, uint32_t type, | 
 |                   bool rela = true, int64_t addend = 0) : | 
 |       r_offset(off), r_symidx(sym), r_type(type), | 
 |       r_add(addend), r_rela(rela) {} | 
 |   }; | 
 |  | 
 | } // end namespace llvm | 
 |  | 
 | #endif |