//===-- llvm/Support/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 stuff is based on ELF-64 Object File Format
// Version 1.5, Draft 2, May 1998 as well as OpenBSD header files.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_ELF_H
#define LLVM_SUPPORT_ELF_H

#include "llvm/Support/Compiler.h"
#include "llvm/Support/DataTypes.h"
#include <cstring>

namespace llvm {

namespace ELF {

typedef uint32_t Elf32_Addr; // Program address
typedef uint32_t Elf32_Off;  // File offset
typedef uint16_t Elf32_Half;
typedef uint32_t Elf32_Word;
typedef int32_t Elf32_Sword;

typedef uint64_t Elf64_Addr;
typedef uint64_t Elf64_Off;
typedef uint16_t Elf64_Half;
typedef uint32_t Elf64_Word;
typedef int32_t Elf64_Sword;
typedef uint64_t Elf64_Xword;
typedef int64_t Elf64_Sxword;

// Object file magic string.
static const char ElfMagic[] = {0x7f, 'E', 'L', 'F', '\0'};

// e_ident size and indices.
enum {
  EI_MAG0 = 0,       // File identification index.
  EI_MAG1 = 1,       // File identification index.
  EI_MAG2 = 2,       // File identification index.
  EI_MAG3 = 3,       // File identification index.
  EI_CLASS = 4,      // File class.
  EI_DATA = 5,       // Data encoding.
  EI_VERSION = 6,    // File version.
  EI_OSABI = 7,      // OS/ABI identification.
  EI_ABIVERSION = 8, // ABI version.
  EI_PAD = 9,        // Start of padding bytes.
  EI_NIDENT = 16     // Number of bytes in e_ident.
};

struct Elf32_Ehdr {
  unsigned char e_ident[EI_NIDENT]; // ELF Identification bytes
  Elf32_Half e_type;                // Type of file (see ET_* below)
  Elf32_Half e_machine;   // Required architecture for this file (see EM_*)
  Elf32_Word e_version;   // Must be equal to 1
  Elf32_Addr e_entry;     // Address to jump to in order to start program
  Elf32_Off e_phoff;      // Program header table's file offset, in bytes
  Elf32_Off e_shoff;      // Section header table's file offset, in bytes
  Elf32_Word e_flags;     // Processor-specific flags
  Elf32_Half e_ehsize;    // Size of ELF header, in bytes
  Elf32_Half e_phentsize; // Size of an entry in the program header table
  Elf32_Half e_phnum;     // Number of entries in the program header table
  Elf32_Half e_shentsize; // Size of an entry in the section header table
  Elf32_Half e_shnum;     // Number of entries in the section header table
  Elf32_Half e_shstrndx;  // Sect hdr table index of sect name string table
  bool checkMagic() const {
    return (memcmp(e_ident, ElfMagic, strlen(ElfMagic))) == 0;
  }
  unsigned char getFileClass() const { return e_ident[EI_CLASS]; }
  unsigned char getDataEncoding() const { return e_ident[EI_DATA]; }
};

// 64-bit ELF header. Fields are the same as for ELF32, but with different
// types (see above).
struct Elf64_Ehdr {
  unsigned char e_ident[EI_NIDENT];
  Elf64_Half e_type;
  Elf64_Half e_machine;
  Elf64_Word e_version;
  Elf64_Addr e_entry;
  Elf64_Off e_phoff;
  Elf64_Off e_shoff;
  Elf64_Word e_flags;
  Elf64_Half e_ehsize;
  Elf64_Half e_phentsize;
  Elf64_Half e_phnum;
  Elf64_Half e_shentsize;
  Elf64_Half e_shnum;
  Elf64_Half e_shstrndx;
  bool checkMagic() const {
    return (memcmp(e_ident, ElfMagic, strlen(ElfMagic))) == 0;
  }
  unsigned char getFileClass() const { return e_ident[EI_CLASS]; }
  unsigned char getDataEncoding() const { return e_ident[EI_DATA]; }
};

// File types
enum {
  ET_NONE = 0,        // No file type
  ET_REL = 1,         // Relocatable file
  ET_EXEC = 2,        // Executable file
  ET_DYN = 3,         // Shared object file
  ET_CORE = 4,        // Core file
  ET_LOPROC = 0xff00, // Beginning of processor-specific codes
  ET_HIPROC = 0xffff  // Processor-specific
};

// Versioning
enum { EV_NONE = 0, EV_CURRENT = 1 };

// Machine architectures
// See current registered ELF machine architectures at:
//    http://www.uxsglobal.com/developers/gabi/latest/ch4.eheader.html
enum {
  EM_NONE = 0,           // No machine
  EM_M32 = 1,            // AT&T WE 32100
  EM_SPARC = 2,          // SPARC
  EM_386 = 3,            // Intel 386
  EM_68K = 4,            // Motorola 68000
  EM_88K = 5,            // Motorola 88000
  EM_IAMCU = 6,          // Intel MCU
  EM_860 = 7,            // Intel 80860
  EM_MIPS = 8,           // MIPS R3000
  EM_S370 = 9,           // IBM System/370
  EM_MIPS_RS3_LE = 10,   // MIPS RS3000 Little-endian
  EM_PARISC = 15,        // Hewlett-Packard PA-RISC
  EM_VPP500 = 17,        // Fujitsu VPP500
  EM_SPARC32PLUS = 18,   // Enhanced instruction set SPARC
  EM_960 = 19,           // Intel 80960
  EM_PPC = 20,           // PowerPC
  EM_PPC64 = 21,         // PowerPC64
  EM_S390 = 22,          // IBM System/390
  EM_SPU = 23,           // IBM SPU/SPC
  EM_V800 = 36,          // NEC V800
  EM_FR20 = 37,          // Fujitsu FR20
  EM_RH32 = 38,          // TRW RH-32
  EM_RCE = 39,           // Motorola RCE
  EM_ARM = 40,           // ARM
  EM_ALPHA = 41,         // DEC Alpha
  EM_SH = 42,            // Hitachi SH
  EM_SPARCV9 = 43,       // SPARC V9
  EM_TRICORE = 44,       // Siemens TriCore
  EM_ARC = 45,           // Argonaut RISC Core
  EM_H8_300 = 46,        // Hitachi H8/300
  EM_H8_300H = 47,       // Hitachi H8/300H
  EM_H8S = 48,           // Hitachi H8S
  EM_H8_500 = 49,        // Hitachi H8/500
  EM_IA_64 = 50,         // Intel IA-64 processor architecture
  EM_MIPS_X = 51,        // Stanford MIPS-X
  EM_COLDFIRE = 52,      // Motorola ColdFire
  EM_68HC12 = 53,        // Motorola M68HC12
  EM_MMA = 54,           // Fujitsu MMA Multimedia Accelerator
  EM_PCP = 55,           // Siemens PCP
  EM_NCPU = 56,          // Sony nCPU embedded RISC processor
  EM_NDR1 = 57,          // Denso NDR1 microprocessor
  EM_STARCORE = 58,      // Motorola Star*Core processor
  EM_ME16 = 59,          // Toyota ME16 processor
  EM_ST100 = 60,         // STMicroelectronics ST100 processor
  EM_TINYJ = 61,         // Advanced Logic Corp. TinyJ embedded processor family
  EM_X86_64 = 62,        // AMD x86-64 architecture
  EM_PDSP = 63,          // Sony DSP Processor
  EM_PDP10 = 64,         // Digital Equipment Corp. PDP-10
  EM_PDP11 = 65,         // Digital Equipment Corp. PDP-11
  EM_FX66 = 66,          // Siemens FX66 microcontroller
  EM_ST9PLUS = 67,       // STMicroelectronics ST9+ 8/16 bit microcontroller
  EM_ST7 = 68,           // STMicroelectronics ST7 8-bit microcontroller
  EM_68HC16 = 69,        // Motorola MC68HC16 Microcontroller
  EM_68HC11 = 70,        // Motorola MC68HC11 Microcontroller
  EM_68HC08 = 71,        // Motorola MC68HC08 Microcontroller
  EM_68HC05 = 72,        // Motorola MC68HC05 Microcontroller
  EM_SVX = 73,           // Silicon Graphics SVx
  EM_ST19 = 74,          // STMicroelectronics ST19 8-bit microcontroller
  EM_VAX = 75,           // Digital VAX
  EM_CRIS = 76,          // Axis Communications 32-bit embedded processor
  EM_JAVELIN = 77,       // Infineon Technologies 32-bit embedded processor
  EM_FIREPATH = 78,      // Element 14 64-bit DSP Processor
  EM_ZSP = 79,           // LSI Logic 16-bit DSP Processor
  EM_MMIX = 80,          // Donald Knuth's educational 64-bit processor
  EM_HUANY = 81,         // Harvard University machine-independent object files
  EM_PRISM = 82,         // SiTera Prism
  EM_AVR = 83,           // Atmel AVR 8-bit microcontroller
  EM_FR30 = 84,          // Fujitsu FR30
  EM_D10V = 85,          // Mitsubishi D10V
  EM_D30V = 86,          // Mitsubishi D30V
  EM_V850 = 87,          // NEC v850
  EM_M32R = 88,          // Mitsubishi M32R
  EM_MN10300 = 89,       // Matsushita MN10300
  EM_MN10200 = 90,       // Matsushita MN10200
  EM_PJ = 91,            // picoJava
  EM_OPENRISC = 92,      // OpenRISC 32-bit embedded processor
  EM_ARC_COMPACT = 93,   // ARC International ARCompact processor (old
                         // spelling/synonym: EM_ARC_A5)
  EM_XTENSA = 94,        // Tensilica Xtensa Architecture
  EM_VIDEOCORE = 95,     // Alphamosaic VideoCore processor
  EM_TMM_GPP = 96,       // Thompson Multimedia General Purpose Processor
  EM_NS32K = 97,         // National Semiconductor 32000 series
  EM_TPC = 98,           // Tenor Network TPC processor
  EM_SNP1K = 99,         // Trebia SNP 1000 processor
  EM_ST200 = 100,        // STMicroelectronics (www.st.com) ST200
  EM_IP2K = 101,         // Ubicom IP2xxx microcontroller family
  EM_MAX = 102,          // MAX Processor
  EM_CR = 103,           // National Semiconductor CompactRISC microprocessor
  EM_F2MC16 = 104,       // Fujitsu F2MC16
  EM_MSP430 = 105,       // Texas Instruments embedded microcontroller msp430
  EM_BLACKFIN = 106,     // Analog Devices Blackfin (DSP) processor
  EM_SE_C33 = 107,       // S1C33 Family of Seiko Epson processors
  EM_SEP = 108,          // Sharp embedded microprocessor
  EM_ARCA = 109,         // Arca RISC Microprocessor
  EM_UNICORE = 110,      // Microprocessor series from PKU-Unity Ltd. and MPRC
                         // of Peking University
  EM_EXCESS = 111,       // eXcess: 16/32/64-bit configurable embedded CPU
  EM_DXP = 112,          // Icera Semiconductor Inc. Deep Execution Processor
  EM_ALTERA_NIOS2 = 113, // Altera Nios II soft-core processor
  EM_CRX = 114,          // National Semiconductor CompactRISC CRX
  EM_XGATE = 115,        // Motorola XGATE embedded processor
  EM_C166 = 116,         // Infineon C16x/XC16x processor
  EM_M16C = 117,         // Renesas M16C series microprocessors
  EM_DSPIC30F = 118,     // Microchip Technology dsPIC30F Digital Signal
                         // Controller
  EM_CE = 119,           // Freescale Communication Engine RISC core
  EM_M32C = 120,         // Renesas M32C series microprocessors
  EM_TSK3000 = 131,      // Altium TSK3000 core
  EM_RS08 = 132,         // Freescale RS08 embedded processor
  EM_SHARC = 133,        // Analog Devices SHARC family of 32-bit DSP
                         // processors
  EM_ECOG2 = 134,        // Cyan Technology eCOG2 microprocessor
  EM_SCORE7 = 135,       // Sunplus S+core7 RISC processor
  EM_DSP24 = 136,        // New Japan Radio (NJR) 24-bit DSP Processor
  EM_VIDEOCORE3 = 137,   // Broadcom VideoCore III processor
  EM_LATTICEMICO32 = 138, // RISC processor for Lattice FPGA architecture
  EM_SE_C17 = 139,        // Seiko Epson C17 family
  EM_TI_C6000 = 140,      // The Texas Instruments TMS320C6000 DSP family
  EM_TI_C2000 = 141,      // The Texas Instruments TMS320C2000 DSP family
  EM_TI_C5500 = 142,      // The Texas Instruments TMS320C55x DSP family
  EM_MMDSP_PLUS = 160,    // STMicroelectronics 64bit VLIW Data Signal Processor
  EM_CYPRESS_M8C = 161,   // Cypress M8C microprocessor
  EM_R32C = 162,          // Renesas R32C series microprocessors
  EM_TRIMEDIA = 163,      // NXP Semiconductors TriMedia architecture family
  EM_HEXAGON = 164,       // Qualcomm Hexagon processor
  EM_8051 = 165,          // Intel 8051 and variants
  EM_STXP7X = 166,        // STMicroelectronics STxP7x family of configurable
                          // and extensible RISC processors
  EM_NDS32 = 167,         // Andes Technology compact code size embedded RISC
                          // processor family
  EM_ECOG1 = 168,         // Cyan Technology eCOG1X family
  EM_ECOG1X = 168,        // Cyan Technology eCOG1X family
  EM_MAXQ30 = 169,        // Dallas Semiconductor MAXQ30 Core Micro-controllers
  EM_XIMO16 = 170,        // New Japan Radio (NJR) 16-bit DSP Processor
  EM_MANIK = 171,         // M2000 Reconfigurable RISC Microprocessor
  EM_CRAYNV2 = 172,       // Cray Inc. NV2 vector architecture
  EM_RX = 173,            // Renesas RX family
  EM_METAG = 174,         // Imagination Technologies META processor
                          // architecture
  EM_MCST_ELBRUS = 175,   // MCST Elbrus general purpose hardware architecture
  EM_ECOG16 = 176,        // Cyan Technology eCOG16 family
  EM_CR16 = 177,          // National Semiconductor CompactRISC CR16 16-bit
                          // microprocessor
  EM_ETPU = 178,          // Freescale Extended Time Processing Unit
  EM_SLE9X = 179,         // Infineon Technologies SLE9X core
  EM_L10M = 180,          // Intel L10M
  EM_K10M = 181,          // Intel K10M
  EM_AARCH64 = 183,       // ARM AArch64
  EM_AVR32 = 185,         // Atmel Corporation 32-bit microprocessor family
  EM_STM8 = 186,          // STMicroeletronics STM8 8-bit microcontroller
  EM_TILE64 = 187,        // Tilera TILE64 multicore architecture family
  EM_TILEPRO = 188,       // Tilera TILEPro multicore architecture family
  EM_CUDA = 190,          // NVIDIA CUDA architecture
  EM_TILEGX = 191,        // Tilera TILE-Gx multicore architecture family
  EM_CLOUDSHIELD = 192,   // CloudShield architecture family
  EM_COREA_1ST = 193,     // KIPO-KAIST Core-A 1st generation processor family
  EM_COREA_2ND = 194,     // KIPO-KAIST Core-A 2nd generation processor family
  EM_ARC_COMPACT2 = 195,  // Synopsys ARCompact V2
  EM_OPEN8 = 196,         // Open8 8-bit RISC soft processor core
  EM_RL78 = 197,          // Renesas RL78 family
  EM_VIDEOCORE5 = 198,    // Broadcom VideoCore V processor
  EM_78KOR = 199,         // Renesas 78KOR family
  EM_56800EX = 200,       // Freescale 56800EX Digital Signal Controller (DSC)
  EM_BA1 = 201,           // Beyond BA1 CPU architecture
  EM_BA2 = 202,           // Beyond BA2 CPU architecture
  EM_XCORE = 203,         // XMOS xCORE processor family
  EM_MCHP_PIC = 204,      // Microchip 8-bit PIC(r) family
  EM_INTEL205 = 205,      // Reserved by Intel
  EM_INTEL206 = 206,      // Reserved by Intel
  EM_INTEL207 = 207,      // Reserved by Intel
  EM_INTEL208 = 208,      // Reserved by Intel
  EM_INTEL209 = 209,      // Reserved by Intel
  EM_KM32 = 210,          // KM211 KM32 32-bit processor
  EM_KMX32 = 211,         // KM211 KMX32 32-bit processor
  EM_KMX16 = 212,         // KM211 KMX16 16-bit processor
  EM_KMX8 = 213,          // KM211 KMX8 8-bit processor
  EM_KVARC = 214,         // KM211 KVARC processor
  EM_CDP = 215,           // Paneve CDP architecture family
  EM_COGE = 216,          // Cognitive Smart Memory Processor
  EM_COOL = 217,          // iCelero CoolEngine
  EM_NORC = 218,          // Nanoradio Optimized RISC
  EM_CSR_KALIMBA = 219,   // CSR Kalimba architecture family
  EM_AMDGPU = 224,        // AMD GPU architecture
  EM_RISCV = 243,         // RISC-V
  EM_LANAI = 244,         // Lanai 32-bit processor
  EM_BPF = 247,           // Linux kernel bpf virtual machine

  // A request has been made to the maintainer of the official registry for
  // such numbers for an official value for WebAssembly. As soon as one is
  // allocated, this enum will be updated to use it.
  EM_WEBASSEMBLY = 0x4157, // WebAssembly architecture
};

// Object file classes.
enum {
  ELFCLASSNONE = 0,
  ELFCLASS32 = 1, // 32-bit object file
  ELFCLASS64 = 2  // 64-bit object file
};

// Object file byte orderings.
enum {
  ELFDATANONE = 0, // Invalid data encoding.
  ELFDATA2LSB = 1, // Little-endian object file
  ELFDATA2MSB = 2  // Big-endian object file
};

// OS ABI identification.
enum {
  ELFOSABI_NONE = 0,          // UNIX System V ABI
  ELFOSABI_HPUX = 1,          // HP-UX operating system
  ELFOSABI_NETBSD = 2,        // NetBSD
  ELFOSABI_GNU = 3,           // GNU/Linux
  ELFOSABI_LINUX = 3,         // Historical alias for ELFOSABI_GNU.
  ELFOSABI_HURD = 4,          // GNU/Hurd
  ELFOSABI_SOLARIS = 6,       // Solaris
  ELFOSABI_AIX = 7,           // AIX
  ELFOSABI_IRIX = 8,          // IRIX
  ELFOSABI_FREEBSD = 9,       // FreeBSD
  ELFOSABI_TRU64 = 10,        // TRU64 UNIX
  ELFOSABI_MODESTO = 11,      // Novell Modesto
  ELFOSABI_OPENBSD = 12,      // OpenBSD
  ELFOSABI_OPENVMS = 13,      // OpenVMS
  ELFOSABI_NSK = 14,          // Hewlett-Packard Non-Stop Kernel
  ELFOSABI_AROS = 15,         // AROS
  ELFOSABI_FENIXOS = 16,      // FenixOS
  ELFOSABI_CLOUDABI = 17,     // Nuxi CloudABI
  ELFOSABI_C6000_ELFABI = 64, // Bare-metal TMS320C6000
  ELFOSABI_AMDGPU_HSA = 64,   // AMD HSA runtime
  ELFOSABI_C6000_LINUX = 65,  // Linux TMS320C6000
  ELFOSABI_ARM = 97,          // ARM
  ELFOSABI_STANDALONE = 255   // Standalone (embedded) application
};

#define ELF_RELOC(name, value) name = value,

// X86_64 relocations.
enum {
#include "ELFRelocs/x86_64.def"
};

// i386 relocations.
enum {
#include "ELFRelocs/i386.def"
};

// ELF Relocation types for PPC32
enum {
#include "ELFRelocs/PowerPC.def"
};

// Specific e_flags for PPC64
enum {
  // e_flags bits specifying ABI:
  // 1 for original ABI using function descriptors,
  // 2 for revised ABI without function descriptors,
  // 0 for unspecified or not using any features affected by the differences.
  EF_PPC64_ABI = 3
};

// Special values for the st_other field in the symbol table entry for PPC64.
enum {
  STO_PPC64_LOCAL_BIT = 5,
  STO_PPC64_LOCAL_MASK = (7 << STO_PPC64_LOCAL_BIT)
};
static inline int64_t decodePPC64LocalEntryOffset(unsigned Other) {
  unsigned Val = (Other & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT;
  return ((1 << Val) >> 2) << 2;
}
static inline unsigned encodePPC64LocalEntryOffset(int64_t Offset) {
  unsigned Val =
      (Offset >= 4 * 4 ? (Offset >= 8 * 4 ? (Offset >= 16 * 4 ? 6 : 5) : 4)
                       : (Offset >= 2 * 4 ? 3 : (Offset >= 1 * 4 ? 2 : 0)));
  return Val << STO_PPC64_LOCAL_BIT;
}

// ELF Relocation types for PPC64
enum {
#include "ELFRelocs/PowerPC64.def"
};

// ELF Relocation types for AArch64
enum {
#include "ELFRelocs/AArch64.def"
};

// ARM Specific e_flags
enum : unsigned {
  EF_ARM_SOFT_FLOAT = 0x00000200U,
  EF_ARM_VFP_FLOAT = 0x00000400U,
  EF_ARM_EABI_UNKNOWN = 0x00000000U,
  EF_ARM_EABI_VER1 = 0x01000000U,
  EF_ARM_EABI_VER2 = 0x02000000U,
  EF_ARM_EABI_VER3 = 0x03000000U,
  EF_ARM_EABI_VER4 = 0x04000000U,
  EF_ARM_EABI_VER5 = 0x05000000U,
  EF_ARM_EABIMASK = 0xFF000000U
};

// ELF Relocation types for ARM
enum {
#include "ELFRelocs/ARM.def"
};

// AVR specific e_flags
enum : unsigned {
  EF_AVR_ARCH_AVR1 = 1,
  EF_AVR_ARCH_AVR2 = 2,
  EF_AVR_ARCH_AVR25 = 25,
  EF_AVR_ARCH_AVR3 = 3,
  EF_AVR_ARCH_AVR31 = 31,
  EF_AVR_ARCH_AVR35 = 35,
  EF_AVR_ARCH_AVR4 = 4,
  EF_AVR_ARCH_AVR5 = 5,
  EF_AVR_ARCH_AVR51 = 51,
  EF_AVR_ARCH_AVR6 = 6,
  EF_AVR_ARCH_AVRTINY = 100,
  EF_AVR_ARCH_XMEGA1 = 101,
  EF_AVR_ARCH_XMEGA2 = 102,
  EF_AVR_ARCH_XMEGA3 = 103,
  EF_AVR_ARCH_XMEGA4 = 104,
  EF_AVR_ARCH_XMEGA5 = 105,
  EF_AVR_ARCH_XMEGA6 = 106,
  EF_AVR_ARCH_XMEGA7 = 107
};

// ELF Relocation types for AVR
enum {
#include "ELFRelocs/AVR.def"
};

// Mips Specific e_flags
enum : unsigned {
  EF_MIPS_NOREORDER = 0x00000001, // Don't reorder instructions
  EF_MIPS_PIC = 0x00000002,       // Position independent code
  EF_MIPS_CPIC = 0x00000004,      // Call object with Position independent code
  EF_MIPS_ABI2 = 0x00000020,      // File uses N32 ABI
  EF_MIPS_32BITMODE = 0x00000100, // Code compiled for a 64-bit machine
                                  // in 32-bit mode
  EF_MIPS_FP64 = 0x00000200,      // Code compiled for a 32-bit machine
                                  // but uses 64-bit FP registers
  EF_MIPS_NAN2008 = 0x00000400,   // Uses IEE 754-2008 NaN encoding

  // ABI flags
  EF_MIPS_ABI_O32 = 0x00001000, // This file follows the first MIPS 32 bit ABI
  EF_MIPS_ABI_O64 = 0x00002000, // O32 ABI extended for 64-bit architecture.
  EF_MIPS_ABI_EABI32 = 0x00003000, // EABI in 32 bit mode.
  EF_MIPS_ABI_EABI64 = 0x00004000, // EABI in 64 bit mode.
  EF_MIPS_ABI = 0x0000f000,        // Mask for selecting EF_MIPS_ABI_ variant.

  // MIPS machine variant
  EF_MIPS_MACH_NONE = 0x00000000,    // A standard MIPS implementation.
  EF_MIPS_MACH_3900 = 0x00810000,    // Toshiba R3900
  EF_MIPS_MACH_4010 = 0x00820000,    // LSI R4010
  EF_MIPS_MACH_4100 = 0x00830000,    // NEC VR4100
  EF_MIPS_MACH_4650 = 0x00850000,    // MIPS R4650
  EF_MIPS_MACH_4120 = 0x00870000,    // NEC VR4120
  EF_MIPS_MACH_4111 = 0x00880000,    // NEC VR4111/VR4181
  EF_MIPS_MACH_SB1 = 0x008a0000,     // Broadcom SB-1
  EF_MIPS_MACH_OCTEON = 0x008b0000,  // Cavium Networks Octeon
  EF_MIPS_MACH_XLR = 0x008c0000,     // RMI Xlr
  EF_MIPS_MACH_OCTEON2 = 0x008d0000, // Cavium Networks Octeon2
  EF_MIPS_MACH_OCTEON3 = 0x008e0000, // Cavium Networks Octeon3
  EF_MIPS_MACH_5400 = 0x00910000,    // NEC VR5400
  EF_MIPS_MACH_5900 = 0x00920000,    // MIPS R5900
  EF_MIPS_MACH_5500 = 0x00980000,    // NEC VR5500
  EF_MIPS_MACH_9000 = 0x00990000,    // Unknown
  EF_MIPS_MACH_LS2E = 0x00a00000,    // ST Microelectronics Loongson 2E
  EF_MIPS_MACH_LS2F = 0x00a10000,    // ST Microelectronics Loongson 2F
  EF_MIPS_MACH_LS3A = 0x00a20000,    // Loongson 3A
  EF_MIPS_MACH = 0x00ff0000,         // EF_MIPS_MACH_xxx selection mask

  // ARCH_ASE
  EF_MIPS_MICROMIPS = 0x02000000,     // microMIPS
  EF_MIPS_ARCH_ASE_M16 = 0x04000000,  // Has Mips-16 ISA extensions
  EF_MIPS_ARCH_ASE_MDMX = 0x08000000, // Has MDMX multimedia extensions
  EF_MIPS_ARCH_ASE = 0x0f000000,      // Mask for EF_MIPS_ARCH_ASE_xxx flags

  // ARCH
  EF_MIPS_ARCH_1 = 0x00000000,    // MIPS1 instruction set
  EF_MIPS_ARCH_2 = 0x10000000,    // MIPS2 instruction set
  EF_MIPS_ARCH_3 = 0x20000000,    // MIPS3 instruction set
  EF_MIPS_ARCH_4 = 0x30000000,    // MIPS4 instruction set
  EF_MIPS_ARCH_5 = 0x40000000,    // MIPS5 instruction set
  EF_MIPS_ARCH_32 = 0x50000000,   // MIPS32 instruction set per linux not elf.h
  EF_MIPS_ARCH_64 = 0x60000000,   // MIPS64 instruction set per linux not elf.h
  EF_MIPS_ARCH_32R2 = 0x70000000, // mips32r2, mips32r3, mips32r5
  EF_MIPS_ARCH_64R2 = 0x80000000, // mips64r2, mips64r3, mips64r5
  EF_MIPS_ARCH_32R6 = 0x90000000, // mips32r6
  EF_MIPS_ARCH_64R6 = 0xa0000000, // mips64r6
  EF_MIPS_ARCH = 0xf0000000       // Mask for applying EF_MIPS_ARCH_ variant
};

// ELF Relocation types for Mips
enum {
#include "ELFRelocs/Mips.def"
};

// Special values for the st_other field in the symbol table entry for MIPS.
enum {
  STO_MIPS_OPTIONAL = 0x04,  // Symbol whose definition is optional
  STO_MIPS_PLT = 0x08,       // PLT entry related dynamic table record
  STO_MIPS_PIC = 0x20,       // PIC func in an object mixes PIC/non-PIC
  STO_MIPS_MICROMIPS = 0x80, // MIPS Specific ISA for MicroMips
  STO_MIPS_MIPS16 = 0xf0     // MIPS Specific ISA for Mips16
};

// .MIPS.options section descriptor kinds
enum {
  ODK_NULL = 0,       // Undefined
  ODK_REGINFO = 1,    // Register usage information
  ODK_EXCEPTIONS = 2, // Exception processing options
  ODK_PAD = 3,        // Section padding options
  ODK_HWPATCH = 4,    // Hardware patches applied
  ODK_FILL = 5,       // Linker fill value
  ODK_TAGS = 6,       // Space for tool identification
  ODK_HWAND = 7,      // Hardware AND patches applied
  ODK_HWOR = 8,       // Hardware OR patches applied
  ODK_GP_GROUP = 9,   // GP group to use for text/data sections
  ODK_IDENT = 10,     // ID information
  ODK_PAGESIZE = 11   // Page size information
};

// Hexagon-specific e_flags
enum {
  // Object processor version flags, bits[11:0]
  EF_HEXAGON_MACH_V2 = 0x00000001,  // Hexagon V2
  EF_HEXAGON_MACH_V3 = 0x00000002,  // Hexagon V3
  EF_HEXAGON_MACH_V4 = 0x00000003,  // Hexagon V4
  EF_HEXAGON_MACH_V5 = 0x00000004,  // Hexagon V5
  EF_HEXAGON_MACH_V55 = 0x00000005, // Hexagon V55
  EF_HEXAGON_MACH_V60 = 0x00000060, // Hexagon V60
  EF_HEXAGON_MACH_V62 = 0x00000062, // Hexagon V62

  // Highest ISA version flags
  EF_HEXAGON_ISA_MACH = 0x00000000, // Same as specified in bits[11:0]
                                    // of e_flags
  EF_HEXAGON_ISA_V2 = 0x00000010,   // Hexagon V2 ISA
  EF_HEXAGON_ISA_V3 = 0x00000020,   // Hexagon V3 ISA
  EF_HEXAGON_ISA_V4 = 0x00000030,   // Hexagon V4 ISA
  EF_HEXAGON_ISA_V5 = 0x00000040,   // Hexagon V5 ISA
  EF_HEXAGON_ISA_V55 = 0x00000050,  // Hexagon V55 ISA
  EF_HEXAGON_ISA_V60 = 0x00000060,  // Hexagon V60 ISA
  EF_HEXAGON_ISA_V62 = 0x00000062,  // Hexagon V62 ISA
};

// Hexagon-specific section indexes for common small data
enum {
  SHN_HEXAGON_SCOMMON = 0xff00,   // Other access sizes
  SHN_HEXAGON_SCOMMON_1 = 0xff01, // Byte-sized access
  SHN_HEXAGON_SCOMMON_2 = 0xff02, // Half-word-sized access
  SHN_HEXAGON_SCOMMON_4 = 0xff03, // Word-sized access
  SHN_HEXAGON_SCOMMON_8 = 0xff04  // Double-word-size access
};

// ELF Relocation types for Hexagon
enum {
#include "ELFRelocs/Hexagon.def"
};

// ELF Relocation type for Lanai.
enum {
#include "ELFRelocs/Lanai.def"
};

// ELF Relocation types for RISC-V
enum {
#include "ELFRelocs/RISCV.def"
};

// ELF Relocation types for S390/zSeries
enum {
#include "ELFRelocs/SystemZ.def"
};

// ELF Relocation type for Sparc.
enum {
#include "ELFRelocs/Sparc.def"
};

// ELF Relocation types for WebAssembly
enum {
#include "ELFRelocs/WebAssembly.def"
};

// ELF Relocation types for AMDGPU
enum {
#include "ELFRelocs/AMDGPU.def"
};

// ELF Relocation types for BPF
enum {
#include "ELFRelocs/BPF.def"
};

#undef ELF_RELOC

// Section header.
struct Elf32_Shdr {
  Elf32_Word sh_name;      // Section name (index into string table)
  Elf32_Word sh_type;      // Section type (SHT_*)
  Elf32_Word sh_flags;     // Section flags (SHF_*)
  Elf32_Addr sh_addr;      // Address where section is to be loaded
  Elf32_Off sh_offset;     // File offset of section data, in bytes
  Elf32_Word sh_size;      // Size of section, in bytes
  Elf32_Word sh_link;      // Section type-specific header table index link
  Elf32_Word sh_info;      // Section type-specific extra information
  Elf32_Word sh_addralign; // Section address alignment
  Elf32_Word sh_entsize;   // Size of records contained within the section
};

// Section header for ELF64 - same fields as ELF32, different types.
struct Elf64_Shdr {
  Elf64_Word sh_name;
  Elf64_Word sh_type;
  Elf64_Xword sh_flags;
  Elf64_Addr sh_addr;
  Elf64_Off sh_offset;
  Elf64_Xword sh_size;
  Elf64_Word sh_link;
  Elf64_Word sh_info;
  Elf64_Xword sh_addralign;
  Elf64_Xword sh_entsize;
};

// Special section indices.
enum {
  SHN_UNDEF = 0,          // Undefined, missing, irrelevant, or meaningless
  SHN_LORESERVE = 0xff00, // Lowest reserved index
  SHN_LOPROC = 0xff00,    // Lowest processor-specific index
  SHN_HIPROC = 0xff1f,    // Highest processor-specific index
  SHN_LOOS = 0xff20,      // Lowest operating system-specific index
  SHN_HIOS = 0xff3f,      // Highest operating system-specific index
  SHN_ABS = 0xfff1,       // Symbol has absolute value; does not need relocation
  SHN_COMMON = 0xfff2,    // FORTRAN COMMON or C external global variables
  SHN_XINDEX = 0xffff,    // Mark that the index is >= SHN_LORESERVE
  SHN_HIRESERVE = 0xffff  // Highest reserved index
};

// Section types.
enum : unsigned {
  SHT_NULL = 0,                    // No associated section (inactive entry).
  SHT_PROGBITS = 1,                // Program-defined contents.
  SHT_SYMTAB = 2,                  // Symbol table.
  SHT_STRTAB = 3,                  // String table.
  SHT_RELA = 4,                    // Relocation entries; explicit addends.
  SHT_HASH = 5,                    // Symbol hash table.
  SHT_DYNAMIC = 6,                 // Information for dynamic linking.
  SHT_NOTE = 7,                    // Information about the file.
  SHT_NOBITS = 8,                  // Data occupies no space in the file.
  SHT_REL = 9,                     // Relocation entries; no explicit addends.
  SHT_SHLIB = 10,                  // Reserved.
  SHT_DYNSYM = 11,                 // Symbol table.
  SHT_INIT_ARRAY = 14,             // Pointers to initialization functions.
  SHT_FINI_ARRAY = 15,             // Pointers to termination functions.
  SHT_PREINIT_ARRAY = 16,          // Pointers to pre-init functions.
  SHT_GROUP = 17,                  // Section group.
  SHT_SYMTAB_SHNDX = 18,           // Indices for SHN_XINDEX entries.
  SHT_LOOS = 0x60000000,           // Lowest operating system-specific type.
  SHT_GNU_ATTRIBUTES = 0x6ffffff5, // Object attributes.
  SHT_GNU_HASH = 0x6ffffff6,       // GNU-style hash table.
  SHT_GNU_verdef = 0x6ffffffd,     // GNU version definitions.
  SHT_GNU_verneed = 0x6ffffffe,    // GNU version references.
  SHT_GNU_versym = 0x6fffffff,     // GNU symbol versions table.
  SHT_HIOS = 0x6fffffff,           // Highest operating system-specific type.
  SHT_LOPROC = 0x70000000,         // Lowest processor arch-specific type.
  // Fixme: All this is duplicated in MCSectionELF. Why??
  // Exception Index table
  SHT_ARM_EXIDX = 0x70000001U,
  // BPABI DLL dynamic linking pre-emption map
  SHT_ARM_PREEMPTMAP = 0x70000002U,
  //  Object file compatibility attributes
  SHT_ARM_ATTRIBUTES = 0x70000003U,
  SHT_ARM_DEBUGOVERLAY = 0x70000004U,
  SHT_ARM_OVERLAYSECTION = 0x70000005U,
  SHT_HEX_ORDERED = 0x70000000,   // Link editor is to sort the entries in
                                  // this section based on their sizes
  SHT_X86_64_UNWIND = 0x70000001, // Unwind information

  SHT_MIPS_REGINFO = 0x70000006,  // Register usage information
  SHT_MIPS_OPTIONS = 0x7000000d,  // General options
  SHT_MIPS_DWARF = 0x7000001e,    // DWARF debugging section.
  SHT_MIPS_ABIFLAGS = 0x7000002a, // ABI information.

  SHT_HIPROC = 0x7fffffff, // Highest processor arch-specific type.
  SHT_LOUSER = 0x80000000, // Lowest type reserved for applications.
  SHT_HIUSER = 0xffffffff  // Highest type reserved for applications.
};

// Section flags.
enum : unsigned {
  // Section data should be writable during execution.
  SHF_WRITE = 0x1,

  // Section occupies memory during program execution.
  SHF_ALLOC = 0x2,

  // Section contains executable machine instructions.
  SHF_EXECINSTR = 0x4,

  // The data in this section may be merged.
  SHF_MERGE = 0x10,

  // The data in this section is null-terminated strings.
  SHF_STRINGS = 0x20,

  // A field in this section holds a section header table index.
  SHF_INFO_LINK = 0x40U,

  // Adds special ordering requirements for link editors.
  SHF_LINK_ORDER = 0x80U,

  // This section requires special OS-specific processing to avoid incorrect
  // behavior.
  SHF_OS_NONCONFORMING = 0x100U,

  // This section is a member of a section group.
  SHF_GROUP = 0x200U,

  // This section holds Thread-Local Storage.
  SHF_TLS = 0x400U,

  // Identifies a section containing compressed data.
  SHF_COMPRESSED = 0x800U,

  // This section is excluded from the final executable or shared library.
  SHF_EXCLUDE = 0x80000000U,

  // Start of target-specific flags.

  SHF_MASKOS = 0x0ff00000,

  // Bits indicating processor-specific flags.
  SHF_MASKPROC = 0xf0000000,

  /// All sections with the "d" flag are grouped together by the linker to form
  /// the data section and the dp register is set to the start of the section by
  /// the boot code.
  XCORE_SHF_DP_SECTION = 0x10000000,

  /// All sections with the "c" flag are grouped together by the linker to form
  /// the constant pool and the cp register is set to the start of the constant
  /// pool by the boot code.
  XCORE_SHF_CP_SECTION = 0x20000000,

  // If an object file section does not have this flag set, then it may not hold
  // more than 2GB and can be freely referred to in objects using smaller code
  // models. Otherwise, only objects using larger code models can refer to them.
  // For example, a medium code model object can refer to data in a section that
  // sets this flag besides being able to refer to data in a section that does
  // not set it; likewise, a small code model object can refer only to code in a
  // section that does not set this flag.
  SHF_X86_64_LARGE = 0x10000000,

  // All sections with the GPREL flag are grouped into a global data area
  // for faster accesses
  SHF_HEX_GPREL = 0x10000000,

  // Section contains text/data which may be replicated in other sections.
  // Linker must retain only one copy.
  SHF_MIPS_NODUPES = 0x01000000,

  // Linker must generate implicit hidden weak names.
  SHF_MIPS_NAMES = 0x02000000,

  // Section data local to process.
  SHF_MIPS_LOCAL = 0x04000000,

  // Do not strip this section.
  SHF_MIPS_NOSTRIP = 0x08000000,

  // Section must be part of global data area.
  SHF_MIPS_GPREL = 0x10000000,

  // This section should be merged.
  SHF_MIPS_MERGE = 0x20000000,

  // Address size to be inferred from section entry size.
  SHF_MIPS_ADDR = 0x40000000,

  // Section data is string data by default.
  SHF_MIPS_STRING = 0x80000000,

  // Make code section unreadable when in execute-only mode
  SHF_ARM_PURECODE = 0x20000000,

  SHF_AMDGPU_HSA_GLOBAL = 0x00100000,
  SHF_AMDGPU_HSA_READONLY = 0x00200000,
  SHF_AMDGPU_HSA_CODE = 0x00400000,
  SHF_AMDGPU_HSA_AGENT = 0x00800000
};

// Section Group Flags
enum : unsigned {
  GRP_COMDAT = 0x1,
  GRP_MASKOS = 0x0ff00000,
  GRP_MASKPROC = 0xf0000000
};

// Symbol table entries for ELF32.
struct Elf32_Sym {
  Elf32_Word st_name;     // Symbol name (index into string table)
  Elf32_Addr st_value;    // Value or address associated with the symbol
  Elf32_Word st_size;     // Size of the symbol
  unsigned char st_info;  // Symbol's type and binding attributes
  unsigned char st_other; // Must be zero; reserved
  Elf32_Half st_shndx;    // Which section (header table index) it's defined in

  // These accessors and mutators correspond to the ELF32_ST_BIND,
  // ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification:
  unsigned char getBinding() const { return st_info >> 4; }
  unsigned char getType() const { return st_info & 0x0f; }
  void setBinding(unsigned char b) { setBindingAndType(b, getType()); }
  void setType(unsigned char t) { setBindingAndType(getBinding(), t); }
  void setBindingAndType(unsigned char b, unsigned char t) {
    st_info = (b << 4) + (t & 0x0f);
  }
};

// Symbol table entries for ELF64.
struct Elf64_Sym {
  Elf64_Word st_name;     // Symbol name (index into string table)
  unsigned char st_info;  // Symbol's type and binding attributes
  unsigned char st_other; // Must be zero; reserved
  Elf64_Half st_shndx;    // Which section (header tbl index) it's defined in
  Elf64_Addr st_value;    // Value or address associated with the symbol
  Elf64_Xword st_size;    // Size of the symbol

  // These accessors and mutators are identical to those defined for ELF32
  // symbol table entries.
  unsigned char getBinding() const { return st_info >> 4; }
  unsigned char getType() const { return st_info & 0x0f; }
  void setBinding(unsigned char b) { setBindingAndType(b, getType()); }
  void setType(unsigned char t) { setBindingAndType(getBinding(), t); }
  void setBindingAndType(unsigned char b, unsigned char t) {
    st_info = (b << 4) + (t & 0x0f);
  }
};

// The size (in bytes) of symbol table entries.
enum {
  SYMENTRY_SIZE32 = 16, // 32-bit symbol entry size
  SYMENTRY_SIZE64 = 24  // 64-bit symbol entry size.
};

// Symbol bindings.
enum {
  STB_LOCAL = 0,  // Local symbol, not visible outside obj file containing def
  STB_GLOBAL = 1, // Global symbol, visible to all object files being combined
  STB_WEAK = 2,   // Weak symbol, like global but lower-precedence
  STB_GNU_UNIQUE = 10,
  STB_LOOS = 10,   // Lowest operating system-specific binding type
  STB_HIOS = 12,   // Highest operating system-specific binding type
  STB_LOPROC = 13, // Lowest processor-specific binding type
  STB_HIPROC = 15  // Highest processor-specific binding type
};

// Symbol types.
enum {
  STT_NOTYPE = 0,     // Symbol's type is not specified
  STT_OBJECT = 1,     // Symbol is a data object (variable, array, etc.)
  STT_FUNC = 2,       // Symbol is executable code (function, etc.)
  STT_SECTION = 3,    // Symbol refers to a section
  STT_FILE = 4,       // Local, absolute symbol that refers to a file
  STT_COMMON = 5,     // An uninitialized common block
  STT_TLS = 6,        // Thread local data object
  STT_GNU_IFUNC = 10, // GNU indirect function
  STT_LOOS = 10,      // Lowest operating system-specific symbol type
  STT_HIOS = 12,      // Highest operating system-specific symbol type
  STT_LOPROC = 13,    // Lowest processor-specific symbol type
  STT_HIPROC = 15,    // Highest processor-specific symbol type

  // AMDGPU symbol types
  STT_AMDGPU_HSA_KERNEL = 10,
  STT_AMDGPU_HSA_INDIRECT_FUNCTION = 11,
  STT_AMDGPU_HSA_METADATA = 12
};

enum {
  STV_DEFAULT = 0,  // Visibility is specified by binding type
  STV_INTERNAL = 1, // Defined by processor supplements
  STV_HIDDEN = 2,   // Not visible to other components
  STV_PROTECTED = 3 // Visible in other components but not preemptable
};

// Symbol number.
enum { STN_UNDEF = 0 };

// Special relocation symbols used in the MIPS64 ELF relocation entries
enum {
  RSS_UNDEF = 0, // None
  RSS_GP = 1,    // Value of gp
  RSS_GP0 = 2,   // Value of gp used to create object being relocated
  RSS_LOC = 3    // Address of location being relocated
};

// Relocation entry, without explicit addend.
struct Elf32_Rel {
  Elf32_Addr r_offset; // Location (file byte offset, or program virtual addr)
  Elf32_Word r_info;   // Symbol table index and type of relocation to apply

  // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE,
  // and ELF32_R_INFO macros defined in the ELF specification:
  Elf32_Word getSymbol() const { return (r_info >> 8); }
  unsigned char getType() const { return (unsigned char)(r_info & 0x0ff); }
  void setSymbol(Elf32_Word s) { setSymbolAndType(s, getType()); }
  void setType(unsigned char t) { setSymbolAndType(getSymbol(), t); }
  void setSymbolAndType(Elf32_Word s, unsigned char t) {
    r_info = (s << 8) + t;
  }
};

// Relocation entry with explicit addend.
struct Elf32_Rela {
  Elf32_Addr r_offset;  // Location (file byte offset, or program virtual addr)
  Elf32_Word r_info;    // Symbol table index and type of relocation to apply
  Elf32_Sword r_addend; // Compute value for relocatable field by adding this

  // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE,
  // and ELF32_R_INFO macros defined in the ELF specification:
  Elf32_Word getSymbol() const { return (r_info >> 8); }
  unsigned char getType() const { return (unsigned char)(r_info & 0x0ff); }
  void setSymbol(Elf32_Word s) { setSymbolAndType(s, getType()); }
  void setType(unsigned char t) { setSymbolAndType(getSymbol(), t); }
  void setSymbolAndType(Elf32_Word s, unsigned char t) {
    r_info = (s << 8) + t;
  }
};

// Relocation entry, without explicit addend.
struct Elf64_Rel {
  Elf64_Addr r_offset; // Location (file byte offset, or program virtual addr).
  Elf64_Xword r_info;  // Symbol table index and type of relocation to apply.

  // These accessors and mutators correspond to the ELF64_R_SYM, ELF64_R_TYPE,
  // and ELF64_R_INFO macros defined in the ELF specification:
  Elf64_Word getSymbol() const { return (r_info >> 32); }
  Elf64_Word getType() const { return (Elf64_Word)(r_info & 0xffffffffL); }
  void setSymbol(Elf64_Word s) { setSymbolAndType(s, getType()); }
  void setType(Elf64_Word t) { setSymbolAndType(getSymbol(), t); }
  void setSymbolAndType(Elf64_Word s, Elf64_Word t) {
    r_info = ((Elf64_Xword)s << 32) + (t & 0xffffffffL);
  }
};

// Relocation entry with explicit addend.
struct Elf64_Rela {
  Elf64_Addr r_offset; // Location (file byte offset, or program virtual addr).
  Elf64_Xword r_info;  // Symbol table index and type of relocation to apply.
  Elf64_Sxword r_addend; // Compute value for relocatable field by adding this.

  // These accessors and mutators correspond to the ELF64_R_SYM, ELF64_R_TYPE,
  // and ELF64_R_INFO macros defined in the ELF specification:
  Elf64_Word getSymbol() const { return (r_info >> 32); }
  Elf64_Word getType() const { return (Elf64_Word)(r_info & 0xffffffffL); }
  void setSymbol(Elf64_Word s) { setSymbolAndType(s, getType()); }
  void setType(Elf64_Word t) { setSymbolAndType(getSymbol(), t); }
  void setSymbolAndType(Elf64_Word s, Elf64_Word t) {
    r_info = ((Elf64_Xword)s << 32) + (t & 0xffffffffL);
  }
};

// Program header for ELF32.
struct Elf32_Phdr {
  Elf32_Word p_type;   // Type of segment
  Elf32_Off p_offset;  // File offset where segment is located, in bytes
  Elf32_Addr p_vaddr;  // Virtual address of beginning of segment
  Elf32_Addr p_paddr;  // Physical address of beginning of segment (OS-specific)
  Elf32_Word p_filesz; // Num. of bytes in file image of segment (may be zero)
  Elf32_Word p_memsz;  // Num. of bytes in mem image of segment (may be zero)
  Elf32_Word p_flags;  // Segment flags
  Elf32_Word p_align;  // Segment alignment constraint
};

// Program header for ELF64.
struct Elf64_Phdr {
  Elf64_Word p_type;    // Type of segment
  Elf64_Word p_flags;   // Segment flags
  Elf64_Off p_offset;   // File offset where segment is located, in bytes
  Elf64_Addr p_vaddr;   // Virtual address of beginning of segment
  Elf64_Addr p_paddr;   // Physical addr of beginning of segment (OS-specific)
  Elf64_Xword p_filesz; // Num. of bytes in file image of segment (may be zero)
  Elf64_Xword p_memsz;  // Num. of bytes in mem image of segment (may be zero)
  Elf64_Xword p_align;  // Segment alignment constraint
};

// Segment types.
enum {
  PT_NULL = 0,            // Unused segment.
  PT_LOAD = 1,            // Loadable segment.
  PT_DYNAMIC = 2,         // Dynamic linking information.
  PT_INTERP = 3,          // Interpreter pathname.
  PT_NOTE = 4,            // Auxiliary information.
  PT_SHLIB = 5,           // Reserved.
  PT_PHDR = 6,            // The program header table itself.
  PT_TLS = 7,             // The thread-local storage template.
  PT_LOOS = 0x60000000,   // Lowest operating system-specific pt entry type.
  PT_HIOS = 0x6fffffff,   // Highest operating system-specific pt entry type.
  PT_LOPROC = 0x70000000, // Lowest processor-specific program hdr entry type.
  PT_HIPROC = 0x7fffffff, // Highest processor-specific program hdr entry type.

  // x86-64 program header types.
  // These all contain stack unwind tables.
  PT_GNU_EH_FRAME = 0x6474e550,
  PT_SUNW_EH_FRAME = 0x6474e550,
  PT_SUNW_UNWIND = 0x6464e550,

  PT_GNU_STACK = 0x6474e551, // Indicates stack executability.
  PT_GNU_RELRO = 0x6474e552, // Read-only after relocation.

  PT_OPENBSD_RANDOMIZE = 0x65a3dbe6, // Fill with random data.
  PT_OPENBSD_WXNEEDED = 0x65a3dbe7,  // Program does W^X violations.
  PT_OPENBSD_BOOTDATA = 0x65a41be6,  // Section for boot arguments.

  // ARM program header types.
  PT_ARM_ARCHEXT = 0x70000000, // Platform architecture compatibility info
  // These all contain stack unwind tables.
  PT_ARM_EXIDX = 0x70000001,
  PT_ARM_UNWIND = 0x70000001,

  // MIPS program header types.
  PT_MIPS_REGINFO = 0x70000000,  // Register usage information.
  PT_MIPS_RTPROC = 0x70000001,   // Runtime procedure table.
  PT_MIPS_OPTIONS = 0x70000002,  // Options segment.
  PT_MIPS_ABIFLAGS = 0x70000003, // Abiflags segment.

  // AMDGPU program header types.
  PT_AMDGPU_HSA_LOAD_GLOBAL_PROGRAM = 0x60000000,
  PT_AMDGPU_HSA_LOAD_GLOBAL_AGENT = 0x60000001,
  PT_AMDGPU_HSA_LOAD_READONLY_AGENT = 0x60000002,
  PT_AMDGPU_HSA_LOAD_CODE_AGENT = 0x60000003,

  // WebAssembly program header types.
  PT_WEBASSEMBLY_FUNCTIONS = PT_LOPROC + 0, // Function definitions.
};

// Segment flag bits.
enum : unsigned {
  PF_X = 1,                // Execute
  PF_W = 2,                // Write
  PF_R = 4,                // Read
  PF_MASKOS = 0x0ff00000,  // Bits for operating system-specific semantics.
  PF_MASKPROC = 0xf0000000 // Bits for processor-specific semantics.
};

// Dynamic table entry for ELF32.
struct Elf32_Dyn {
  Elf32_Sword d_tag; // Type of dynamic table entry.
  union {
    Elf32_Word d_val; // Integer value of entry.
    Elf32_Addr d_ptr; // Pointer value of entry.
  } d_un;
};

// Dynamic table entry for ELF64.
struct Elf64_Dyn {
  Elf64_Sxword d_tag; // Type of dynamic table entry.
  union {
    Elf64_Xword d_val; // Integer value of entry.
    Elf64_Addr d_ptr;  // Pointer value of entry.
  } d_un;
};

// Dynamic table entry tags.
enum {
  DT_NULL = 0,          // Marks end of dynamic array.
  DT_NEEDED = 1,        // String table offset of needed library.
  DT_PLTRELSZ = 2,      // Size of relocation entries in PLT.
  DT_PLTGOT = 3,        // Address associated with linkage table.
  DT_HASH = 4,          // Address of symbolic hash table.
  DT_STRTAB = 5,        // Address of dynamic string table.
  DT_SYMTAB = 6,        // Address of dynamic symbol table.
  DT_RELA = 7,          // Address of relocation table (Rela entries).
  DT_RELASZ = 8,        // Size of Rela relocation table.
  DT_RELAENT = 9,       // Size of a Rela relocation entry.
  DT_STRSZ = 10,        // Total size of the string table.
  DT_SYMENT = 11,       // Size of a symbol table entry.
  DT_INIT = 12,         // Address of initialization function.
  DT_FINI = 13,         // Address of termination function.
  DT_SONAME = 14,       // String table offset of a shared objects name.
  DT_RPATH = 15,        // String table offset of library search path.
  DT_SYMBOLIC = 16,     // Changes symbol resolution algorithm.
  DT_REL = 17,          // Address of relocation table (Rel entries).
  DT_RELSZ = 18,        // Size of Rel relocation table.
  DT_RELENT = 19,       // Size of a Rel relocation entry.
  DT_PLTREL = 20,       // Type of relocation entry used for linking.
  DT_DEBUG = 21,        // Reserved for debugger.
  DT_TEXTREL = 22,      // Relocations exist for non-writable segments.
  DT_JMPREL = 23,       // Address of relocations associated with PLT.
  DT_BIND_NOW = 24,     // Process all relocations before execution.
  DT_INIT_ARRAY = 25,   // Pointer to array of initialization functions.
  DT_FINI_ARRAY = 26,   // Pointer to array of termination functions.
  DT_INIT_ARRAYSZ = 27, // Size of DT_INIT_ARRAY.
  DT_FINI_ARRAYSZ = 28, // Size of DT_FINI_ARRAY.
  DT_RUNPATH = 29,      // String table offset of lib search path.
  DT_FLAGS = 30,        // Flags.
  DT_ENCODING = 32,     // Values from here to DT_LOOS follow the rules
                        // for the interpretation of the d_un union.

  DT_PREINIT_ARRAY = 32,   // Pointer to array of preinit functions.
  DT_PREINIT_ARRAYSZ = 33, // Size of the DT_PREINIT_ARRAY array.

  DT_LOOS = 0x60000000,   // Start of environment specific tags.
  DT_HIOS = 0x6FFFFFFF,   // End of environment specific tags.
  DT_LOPROC = 0x70000000, // Start of processor specific tags.
  DT_HIPROC = 0x7FFFFFFF, // End of processor specific tags.

  DT_GNU_HASH = 0x6FFFFEF5, // Reference to the GNU hash table.
  DT_TLSDESC_PLT =
      0x6FFFFEF6, // Location of PLT entry for TLS descriptor resolver calls.
  DT_TLSDESC_GOT = 0x6FFFFEF7, // Location of GOT entry used by TLS descriptor
                               // resolver PLT entry.
  DT_RELACOUNT = 0x6FFFFFF9,   // ELF32_Rela count.
  DT_RELCOUNT = 0x6FFFFFFA,    // ELF32_Rel count.

  DT_FLAGS_1 = 0X6FFFFFFB,    // Flags_1.
  DT_VERSYM = 0x6FFFFFF0,     // The address of .gnu.version section.
  DT_VERDEF = 0X6FFFFFFC,     // The address of the version definition table.
  DT_VERDEFNUM = 0X6FFFFFFD,  // The number of entries in DT_VERDEF.
  DT_VERNEED = 0X6FFFFFFE,    // The address of the version Dependency table.
  DT_VERNEEDNUM = 0X6FFFFFFF, // The number of entries in DT_VERNEED.

  // Hexagon specific dynamic table entries
  DT_HEXAGON_SYMSZ = 0x70000000,
  DT_HEXAGON_VER = 0x70000001,
  DT_HEXAGON_PLT = 0x70000002,

  // Mips specific dynamic table entry tags.
  DT_MIPS_RLD_VERSION = 0x70000001,    // 32 bit version number for runtime
                                       // linker interface.
  DT_MIPS_TIME_STAMP = 0x70000002,     // Time stamp.
  DT_MIPS_ICHECKSUM = 0x70000003,      // Checksum of external strings
                                       // and common sizes.
  DT_MIPS_IVERSION = 0x70000004,       // Index of version string
                                       // in string table.
  DT_MIPS_FLAGS = 0x70000005,          // 32 bits of flags.
  DT_MIPS_BASE_ADDRESS = 0x70000006,   // Base address of the segment.
  DT_MIPS_MSYM = 0x70000007,           // Address of .msym section.
  DT_MIPS_CONFLICT = 0x70000008,       // Address of .conflict section.
  DT_MIPS_LIBLIST = 0x70000009,        // Address of .liblist section.
  DT_MIPS_LOCAL_GOTNO = 0x7000000a,    // Number of local global offset
                                       // table entries.
  DT_MIPS_CONFLICTNO = 0x7000000b,     // Number of entries
                                       // in the .conflict section.
  DT_MIPS_LIBLISTNO = 0x70000010,      // Number of entries
                                       // in the .liblist section.
  DT_MIPS_SYMTABNO = 0x70000011,       // Number of entries
                                       // in the .dynsym section.
  DT_MIPS_UNREFEXTNO = 0x70000012,     // Index of first external dynamic symbol
                                       // not referenced locally.
  DT_MIPS_GOTSYM = 0x70000013,         // Index of first dynamic symbol
                                       // in global offset table.
  DT_MIPS_HIPAGENO = 0x70000014,       // Number of page table entries
                                       // in global offset table.
  DT_MIPS_RLD_MAP = 0x70000016,        // Address of run time loader map,
                                       // used for debugging.
  DT_MIPS_DELTA_CLASS = 0x70000017,    // Delta C++ class definition.
  DT_MIPS_DELTA_CLASS_NO = 0x70000018, // Number of entries
                                       // in DT_MIPS_DELTA_CLASS.
  DT_MIPS_DELTA_INSTANCE = 0x70000019, // Delta C++ class instances.
  DT_MIPS_DELTA_INSTANCE_NO = 0x7000001A,     // Number of entries
                                              // in DT_MIPS_DELTA_INSTANCE.
  DT_MIPS_DELTA_RELOC = 0x7000001B,           // Delta relocations.
  DT_MIPS_DELTA_RELOC_NO = 0x7000001C,        // Number of entries
                                              // in DT_MIPS_DELTA_RELOC.
  DT_MIPS_DELTA_SYM = 0x7000001D,             // Delta symbols that Delta
                                              // relocations refer to.
  DT_MIPS_DELTA_SYM_NO = 0x7000001E,          // Number of entries
                                              // in DT_MIPS_DELTA_SYM.
  DT_MIPS_DELTA_CLASSSYM = 0x70000020,        // Delta symbols that hold
                                              // class declarations.
  DT_MIPS_DELTA_CLASSSYM_NO = 0x70000021,     // Number of entries
                                              // in DT_MIPS_DELTA_CLASSSYM.
  DT_MIPS_CXX_FLAGS = 0x70000022,             // Flags indicating information
                                              // about C++ flavor.
  DT_MIPS_PIXIE_INIT = 0x70000023,            // Pixie information.
  DT_MIPS_SYMBOL_LIB = 0x70000024,            // Address of .MIPS.symlib
  DT_MIPS_LOCALPAGE_GOTIDX = 0x70000025,      // The GOT index of the first PTE
                                              // for a segment
  DT_MIPS_LOCAL_GOTIDX = 0x70000026,          // The GOT index of the first PTE
                                              // for a local symbol
  DT_MIPS_HIDDEN_GOTIDX = 0x70000027,         // The GOT index of the first PTE
                                              // for a hidden symbol
  DT_MIPS_PROTECTED_GOTIDX = 0x70000028,      // The GOT index of the first PTE
                                              // for a protected symbol
  DT_MIPS_OPTIONS = 0x70000029,               // Address of `.MIPS.options'.
  DT_MIPS_INTERFACE = 0x7000002A,             // Address of `.interface'.
  DT_MIPS_DYNSTR_ALIGN = 0x7000002B,          // Unknown.
  DT_MIPS_INTERFACE_SIZE = 0x7000002C,        // Size of the .interface section.
  DT_MIPS_RLD_TEXT_RESOLVE_ADDR = 0x7000002D, // Size of rld_text_resolve
                                              // function stored in the GOT.
  DT_MIPS_PERF_SUFFIX = 0x7000002E,  // Default suffix of DSO to be added
                                     // by rld on dlopen() calls.
  DT_MIPS_COMPACT_SIZE = 0x7000002F, // Size of compact relocation
                                     // section (O32).
  DT_MIPS_GP_VALUE = 0x70000030,     // GP value for auxiliary GOTs.
  DT_MIPS_AUX_DYNAMIC = 0x70000031,  // Address of auxiliary .dynamic.
  DT_MIPS_PLTGOT = 0x70000032,       // Address of the base of the PLTGOT.
  DT_MIPS_RWPLT = 0x70000034,        // Points to the base
                                     // of a writable PLT.
  DT_MIPS_RLD_MAP_REL = 0x70000035,  // Relative offset of run time loader
                                     // map, used for debugging.

  // Sun machine-independent extensions.
  DT_AUXILIARY = 0x7FFFFFFD, // Shared object to load before self
  DT_FILTER = 0x7FFFFFFF     // Shared object to get values from
};

// DT_FLAGS values.
enum {
  DF_ORIGIN = 0x01,    // The object may reference $ORIGIN.
  DF_SYMBOLIC = 0x02,  // Search the shared lib before searching the exe.
  DF_TEXTREL = 0x04,   // Relocations may modify a non-writable segment.
  DF_BIND_NOW = 0x08,  // Process all relocations on load.
  DF_STATIC_TLS = 0x10 // Reject attempts to load dynamically.
};

// State flags selectable in the `d_un.d_val' element of the DT_FLAGS_1 entry.
enum {
  DF_1_NOW = 0x00000001,       // Set RTLD_NOW for this object.
  DF_1_GLOBAL = 0x00000002,    // Set RTLD_GLOBAL for this object.
  DF_1_GROUP = 0x00000004,     // Set RTLD_GROUP for this object.
  DF_1_NODELETE = 0x00000008,  // Set RTLD_NODELETE for this object.
  DF_1_LOADFLTR = 0x00000010,  // Trigger filtee loading at runtime.
  DF_1_INITFIRST = 0x00000020, // Set RTLD_INITFIRST for this object.
  DF_1_NOOPEN = 0x00000040,    // Set RTLD_NOOPEN for this object.
  DF_1_ORIGIN = 0x00000080,    // $ORIGIN must be handled.
  DF_1_DIRECT = 0x00000100,    // Direct binding enabled.
  DF_1_TRANS = 0x00000200,
  DF_1_INTERPOSE = 0x00000400,  // Object is used to interpose.
  DF_1_NODEFLIB = 0x00000800,   // Ignore default lib search path.
  DF_1_NODUMP = 0x00001000,     // Object can't be dldump'ed.
  DF_1_CONFALT = 0x00002000,    // Configuration alternative created.
  DF_1_ENDFILTEE = 0x00004000,  // Filtee terminates filters search.
  DF_1_DISPRELDNE = 0x00008000, // Disp reloc applied at build time.
  DF_1_DISPRELPND = 0x00010000, // Disp reloc applied at run-time.
  DF_1_NODIRECT = 0x00020000,   // Object has no-direct binding.
  DF_1_IGNMULDEF = 0x00040000,
  DF_1_NOKSYMS = 0x00080000,
  DF_1_NOHDR = 0x00100000,
  DF_1_EDITED = 0x00200000, // Object is modified after built.
  DF_1_NORELOC = 0x00400000,
  DF_1_SYMINTPOSE = 0x00800000, // Object has individual interposers.
  DF_1_GLOBAUDIT = 0x01000000,  // Global auditing required.
  DF_1_SINGLETON = 0x02000000   // Singleton symbols are used.
};

// DT_MIPS_FLAGS values.
enum {
  RHF_NONE = 0x00000000,                   // No flags.
  RHF_QUICKSTART = 0x00000001,             // Uses shortcut pointers.
  RHF_NOTPOT = 0x00000002,                 // Hash size is not a power of two.
  RHS_NO_LIBRARY_REPLACEMENT = 0x00000004, // Ignore LD_LIBRARY_PATH.
  RHF_NO_MOVE = 0x00000008,                // DSO address may not be relocated.
  RHF_SGI_ONLY = 0x00000010,               // SGI specific features.
  RHF_GUARANTEE_INIT = 0x00000020,         // Guarantee that .init will finish
                                           // executing before any non-init
                                           // code in DSO is called.
  RHF_DELTA_C_PLUS_PLUS = 0x00000040,      // Contains Delta C++ code.
  RHF_GUARANTEE_START_INIT = 0x00000080,   // Guarantee that .init will start
                                           // executing before any non-init
                                           // code in DSO is called.
  RHF_PIXIE = 0x00000100,                  // Generated by pixie.
  RHF_DEFAULT_DELAY_LOAD = 0x00000200,     // Delay-load DSO by default.
  RHF_REQUICKSTART = 0x00000400,           // Object may be requickstarted
  RHF_REQUICKSTARTED = 0x00000800,         // Object has been requickstarted
  RHF_CORD = 0x00001000,                   // Generated by cord.
  RHF_NO_UNRES_UNDEF = 0x00002000,         // Object contains no unresolved
                                           // undef symbols.
  RHF_RLD_ORDER_SAFE = 0x00004000          // Symbol table is in a safe order.
};

// ElfXX_VerDef structure version (GNU versioning)
enum { VER_DEF_NONE = 0, VER_DEF_CURRENT = 1 };

// VerDef Flags (ElfXX_VerDef::vd_flags)
enum { VER_FLG_BASE = 0x1, VER_FLG_WEAK = 0x2, VER_FLG_INFO = 0x4 };

// Special constants for the version table. (SHT_GNU_versym/.gnu.version)
enum {
  VER_NDX_LOCAL = 0,       // Unversioned local symbol
  VER_NDX_GLOBAL = 1,      // Unversioned global symbol
  VERSYM_VERSION = 0x7fff, // Version Index mask
  VERSYM_HIDDEN = 0x8000   // Hidden bit (non-default version)
};

// ElfXX_VerNeed structure version (GNU versioning)
enum { VER_NEED_NONE = 0, VER_NEED_CURRENT = 1 };

// SHT_NOTE section types
enum {
  NT_FREEBSD_THRMISC = 7,
  NT_FREEBSD_PROCSTAT_PROC = 8,
  NT_FREEBSD_PROCSTAT_FILES = 9,
  NT_FREEBSD_PROCSTAT_VMMAP = 10,
  NT_FREEBSD_PROCSTAT_GROUPS = 11,
  NT_FREEBSD_PROCSTAT_UMASK = 12,
  NT_FREEBSD_PROCSTAT_RLIMIT = 13,
  NT_FREEBSD_PROCSTAT_OSREL = 14,
  NT_FREEBSD_PROCSTAT_PSSTRINGS = 15,
  NT_FREEBSD_PROCSTAT_AUXV = 16,
};

enum {
  NT_GNU_ABI_TAG = 1,
  NT_GNU_HWCAP = 2,
  NT_GNU_BUILD_ID = 3,
  NT_GNU_GOLD_VERSION = 4,
};

enum {
  GNU_ABI_TAG_LINUX = 0,
  GNU_ABI_TAG_HURD = 1,
  GNU_ABI_TAG_SOLARIS = 2,
  GNU_ABI_TAG_FREEBSD = 3,
  GNU_ABI_TAG_NETBSD = 4,
  GNU_ABI_TAG_SYLLABLE = 5,
  GNU_ABI_TAG_NACL = 6,
};

// Compressed section header for ELF32.
struct Elf32_Chdr {
  Elf32_Word ch_type;
  Elf32_Word ch_size;
  Elf32_Word ch_addralign;
};

// Compressed section header for ELF64.
struct Elf64_Chdr {
  Elf64_Word ch_type;
  Elf64_Word ch_reserved;
  Elf64_Xword ch_size;
  Elf64_Xword ch_addralign;
};

// Legal values for ch_type field of compressed section header.
enum {
  ELFCOMPRESS_ZLIB = 1,            // ZLIB/DEFLATE algorithm.
  ELFCOMPRESS_LOOS = 0x60000000,   // Start of OS-specific.
  ELFCOMPRESS_HIOS = 0x6fffffff,   // End of OS-specific.
  ELFCOMPRESS_LOPROC = 0x70000000, // Start of processor-specific.
  ELFCOMPRESS_HIPROC = 0x7fffffff  // End of processor-specific.
};

} // end namespace ELF

} // end namespace llvm

#endif