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Diffstat (limited to 'include/llvm/Support/ELF.h')
| -rw-r--r-- | include/llvm/Support/ELF.h | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/include/llvm/Support/ELF.h b/include/llvm/Support/ELF.h new file mode 100644 index 000000000000..aa27946e433b --- /dev/null +++ b/include/llvm/Support/ELF.h @@ -0,0 +1,309 @@ +//===-- 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 not +// standardized, as far as I can tell. It was largely based on information +// I found in OpenBSD header files. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_SUPPORT_ELF_H +#define LLVM_SUPPORT_ELF_H + +#include "llvm/Support/DataTypes.h" +#include <cstring> + +namespace llvm { + +namespace ELF { + +typedef uint32_t Elf32_Addr; // Program address +typedef uint16_t Elf32_Half; +typedef uint32_t Elf32_Off; // File offset +typedef int32_t Elf32_Sword; +typedef uint32_t Elf32_Word; + +typedef uint64_t Elf64_Addr; +typedef uint64_t Elf64_Off; +typedef int32_t Elf64_Shalf; +typedef int32_t Elf64_Sword; +typedef uint32_t Elf64_Word; +typedef int64_t Elf64_Sxword; +typedef uint64_t Elf64_Xword; +typedef uint32_t Elf64_Half; +typedef uint16_t Elf64_Quarter; + +// Object file magic string. +static const char ElfMagic[] = { 0x7f, 'E', 'L', 'F', '\0' }; + +struct Elf32_Ehdr { + unsigned char e_ident[16]; // 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[4]; } + unsigned char getDataEncoding () { return e_ident[5]; } +}; + +// 64-bit ELF header. Fields are the same as for ELF32, but with different +// types (see above). +struct Elf64_Ehdr { + unsigned char e_ident[16]; + Elf64_Quarter e_type; + Elf64_Quarter e_machine; + Elf64_Half e_version; + Elf64_Addr e_entry; + Elf64_Off e_phoff; + Elf64_Off e_shoff; + Elf64_Half e_flags; + Elf64_Quarter e_ehsize; + Elf64_Quarter e_phentsize; + Elf64_Quarter e_phnum; + Elf64_Quarter e_shentsize; + Elf64_Quarter e_shnum; + Elf64_Quarter e_shstrndx; +}; + +// 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 +}; + +// Machine architectures +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_486 = 6, // Intel 486 (deprecated) + EM_860 = 7, // Intel 80860 + EM_MIPS = 8, // MIPS R3000 + EM_PPC = 20, // PowerPC + EM_ARM = 40, // ARM + EM_ALPHA = 41, // DEC Alpha + EM_SPARCV9 = 43, // SPARC V9 + EM_X86_64 = 62 // AMD64 +}; + +// Object file classes. +enum { + ELFCLASS32 = 1, // 32-bit object file + ELFCLASS64 = 2 // 64-bit object file +}; + +// Object file byte orderings. +enum { + ELFDATA2LSB = 1, // Little-endian object file + ELFDATA2MSB = 2 // Big-endian object file +}; + +// 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_Half sh_name; + Elf64_Half sh_type; + Elf64_Xword sh_flags; + Elf64_Addr sh_addr; + Elf64_Off sh_offset; + Elf64_Xword sh_size; + Elf64_Half sh_link; + Elf64_Half 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_ABS = 0xfff1, // Symbol has absolute value; does not need relocation + SHN_COMMON = 0xfff2, // FORTRAN COMMON or C external global variables + SHN_HIRESERVE = 0xffff // Highest reserved index +}; + +// Section types. +enum { + 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_LOPROC = 0x70000000, // Lowest processor architecture-specific type. + SHT_HIPROC = 0x7fffffff, // Highest processor architecture-specific type. + SHT_LOUSER = 0x80000000, // Lowest type reserved for applications. + SHT_HIUSER = 0xffffffff // Highest type reserved for applications. +}; + +// Section flags. +enum { + SHF_WRITE = 0x1, // Section data should be writable during execution. + SHF_ALLOC = 0x2, // Section occupies memory during program execution. + SHF_EXECINSTR = 0x4, // Section contains executable machine instructions. + SHF_MASKPROC = 0xf0000000 // Bits indicating processor-specific flags. +}; + +// Symbol table entries. +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 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_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_LOPROC = 13, // Lowest processor-specific symbol type + STT_HIPROC = 15 // Highest processor-specific symbol type +}; + +// 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; + }; +}; + +// Program header. +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 +}; + +// 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_LOPROC = 0x70000000, // Lowest processor-specific program hdr entry type. + PT_HIPROC = 0x7fffffff // Highest processor-specific program hdr entry type. +}; + +// Segment flag bits. +enum { + PF_X = 1, // Execute + PF_W = 2, // Write + PF_R = 4, // Read + PF_MASKPROC = 0xf0000000 // Unspecified +}; + +} // end namespace ELF + +} // end namespace llvm + +#endif |