1 //===-- llvm/Support/ELF.h - ELF constants and data structures --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header contains common, non-processor-specific data structures and
11 // constants for the ELF file format.
13 // The details of the ELF32 bits in this file are largely based on
14 // the Tool Interface Standard (TIS) Executable and Linking Format
15 // (ELF) Specification Version 1.2, May 1995. The ELF64 stuff is not
16 // standardized, as far as I can tell. It was largely based on information
17 // I found in OpenBSD header files.
19 //===----------------------------------------------------------------------===//
21 #ifndef LLVM_SUPPORT_ELF_H
22 #define LLVM_SUPPORT_ELF_H
24 #include "llvm/Support/DataTypes.h"
31 typedef uint32_t Elf32_Addr; // Program address
32 typedef uint16_t Elf32_Half;
33 typedef uint32_t Elf32_Off; // File offset
34 typedef int32_t Elf32_Sword;
35 typedef uint32_t Elf32_Word;
37 typedef uint64_t Elf64_Addr;
38 typedef uint64_t Elf64_Off;
39 typedef int32_t Elf64_Shalf;
40 typedef int32_t Elf64_Sword;
41 typedef uint32_t Elf64_Word;
42 typedef int64_t Elf64_Sxword;
43 typedef uint64_t Elf64_Xword;
44 typedef uint32_t Elf64_Half;
45 typedef uint16_t Elf64_Quarter;
47 // Object file magic string.
48 static const char ElfMagic[] = { 0x7f, 'E', 'L', 'F', '\0' };
51 unsigned char e_ident[16]; // ELF Identification bytes
52 Elf32_Half e_type; // Type of file (see ET_* below)
53 Elf32_Half e_machine; // Required architecture for this file (see EM_*)
54 Elf32_Word e_version; // Must be equal to 1
55 Elf32_Addr e_entry; // Address to jump to in order to start program
56 Elf32_Off e_phoff; // Program header table's file offset, in bytes
57 Elf32_Off e_shoff; // Section header table's file offset, in bytes
58 Elf32_Word e_flags; // Processor-specific flags
59 Elf32_Half e_ehsize; // Size of ELF header, in bytes
60 Elf32_Half e_phentsize; // Size of an entry in the program header table
61 Elf32_Half e_phnum; // Number of entries in the program header table
62 Elf32_Half e_shentsize; // Size of an entry in the section header table
63 Elf32_Half e_shnum; // Number of entries in the section header table
64 Elf32_Half e_shstrndx; // Sect hdr table index of sect name string table
65 bool checkMagic () const {
66 return (memcmp (e_ident, ElfMagic, strlen (ElfMagic))) == 0;
68 unsigned char getFileClass () const { return e_ident[4]; }
69 unsigned char getDataEncoding () { return e_ident[5]; }
72 // 64-bit ELF header. Fields are the same as for ELF32, but with different
75 unsigned char e_ident[16];
77 Elf64_Quarter e_machine;
83 Elf64_Quarter e_ehsize;
84 Elf64_Quarter e_phentsize;
85 Elf64_Quarter e_phnum;
86 Elf64_Quarter e_shentsize;
87 Elf64_Quarter e_shnum;
88 Elf64_Quarter e_shstrndx;
93 ET_NONE = 0, // No file type
94 ET_REL = 1, // Relocatable file
95 ET_EXEC = 2, // Executable file
96 ET_DYN = 3, // Shared object file
97 ET_CORE = 4, // Core file
98 ET_LOPROC = 0xff00, // Beginning of processor-specific codes
99 ET_HIPROC = 0xffff // Processor-specific
102 // Machine architectures
104 EM_NONE = 0, // No machine
105 EM_M32 = 1, // AT&T WE 32100
106 EM_SPARC = 2, // SPARC
107 EM_386 = 3, // Intel 386
108 EM_68K = 4, // Motorola 68000
109 EM_88K = 5, // Motorola 88000
110 EM_486 = 6, // Intel 486 (deprecated)
111 EM_860 = 7, // Intel 80860
112 EM_MIPS = 8, // MIPS R3000
113 EM_PPC = 20, // PowerPC
115 EM_ALPHA = 41, // DEC Alpha
116 EM_SPARCV9 = 43 // SPARC V9
119 // Object file classes.
121 ELFCLASS32 = 1, // 32-bit object file
122 ELFCLASS64 = 2 // 64-bit object file
125 // Object file byte orderings.
127 ELFDATA2LSB = 1, // Little-endian object file
128 ELFDATA2MSB = 2 // Big-endian object file
133 Elf32_Word sh_name; // Section name (index into string table)
134 Elf32_Word sh_type; // Section type (SHT_*)
135 Elf32_Word sh_flags; // Section flags (SHF_*)
136 Elf32_Addr sh_addr; // Address where section is to be loaded
137 Elf32_Off sh_offset; // File offset of section data, in bytes
138 Elf32_Word sh_size; // Size of section, in bytes
139 Elf32_Word sh_link; // Section type-specific header table index link
140 Elf32_Word sh_info; // Section type-specific extra information
141 Elf32_Word sh_addralign; // Section address alignment
142 Elf32_Word sh_entsize; // Size of records contained within the section
145 // Section header for ELF64 - same fields as ELF32, different types.
149 Elf64_Xword sh_flags;
155 Elf64_Xword sh_addralign;
156 Elf64_Xword sh_entsize;
159 // Special section indices.
161 SHN_UNDEF = 0, // Undefined, missing, irrelevant, or meaningless
162 SHN_LORESERVE = 0xff00, // Lowest reserved index
163 SHN_LOPROC = 0xff00, // Lowest processor-specific index
164 SHN_HIPROC = 0xff1f, // Highest processor-specific index
165 SHN_ABS = 0xfff1, // Symbol has absolute value; does not need relocation
166 SHN_COMMON = 0xfff2, // FORTRAN COMMON or C external global variables
167 SHN_HIRESERVE = 0xffff // Highest reserved index
172 SHT_NULL = 0, // No associated section (inactive entry).
173 SHT_PROGBITS = 1, // Program-defined contents.
174 SHT_SYMTAB = 2, // Symbol table.
175 SHT_STRTAB = 3, // String table.
176 SHT_RELA = 4, // Relocation entries; explicit addends.
177 SHT_HASH = 5, // Symbol hash table.
178 SHT_DYNAMIC = 6, // Information for dynamic linking.
179 SHT_NOTE = 7, // Information about the file.
180 SHT_NOBITS = 8, // Data occupies no space in the file.
181 SHT_REL = 9, // Relocation entries; no explicit addends.
182 SHT_SHLIB = 10, // Reserved.
183 SHT_DYNSYM = 11, // Symbol table.
184 SHT_LOPROC = 0x70000000, // Lowest processor architecture-specific type.
185 SHT_HIPROC = 0x7fffffff, // Highest processor architecture-specific type.
186 SHT_LOUSER = 0x80000000, // Lowest type reserved for applications.
187 SHT_HIUSER = 0xffffffff // Highest type reserved for applications.
192 SHF_WRITE = 0x1, // Section data should be writable during execution.
193 SHF_ALLOC = 0x2, // Section occupies memory during program execution.
194 SHF_EXECINSTR = 0x4, // Section contains executable machine instructions.
195 SHF_MASKPROC = 0xf0000000 // Bits indicating processor-specific flags.
198 // Symbol table entries.
200 Elf32_Word st_name; // Symbol name (index into string table)
201 Elf32_Addr st_value; // Value or address associated with the symbol
202 Elf32_Word st_size; // Size of the symbol
203 unsigned char st_info; // Symbol's type and binding attributes
204 unsigned char st_other; // Must be zero; reserved
205 Elf32_Half st_shndx; // Which section (header table index) it's defined in
207 // These accessors and mutators correspond to the ELF32_ST_BIND,
208 // ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification:
209 unsigned char getBinding () const { return st_info >> 4; }
210 unsigned char getType () const { return st_info & 0x0f; }
211 void setBinding (unsigned char b) { setBindingAndType (b, getType ()); }
212 void setType (unsigned char t) { setBindingAndType (getBinding (), t); }
213 void setBindingAndType (unsigned char b, unsigned char t) {
214 st_info = (b << 4) + (t & 0x0f);
220 STB_LOCAL = 0, // Local symbol, not visible outside obj file containing def
221 STB_GLOBAL = 1, // Global symbol, visible to all object files being combined
222 STB_WEAK = 2, // Weak symbol, like global but lower-precedence
223 STB_LOPROC = 13, // Lowest processor-specific binding type
224 STB_HIPROC = 15 // Highest processor-specific binding type
229 STT_NOTYPE = 0, // Symbol's type is not specified
230 STT_OBJECT = 1, // Symbol is a data object (variable, array, etc.)
231 STT_FUNC = 2, // Symbol is executable code (function, etc.)
232 STT_SECTION = 3, // Symbol refers to a section
233 STT_FILE = 4, // Local, absolute symbol that refers to a file
234 STT_LOPROC = 13, // Lowest processor-specific symbol type
235 STT_HIPROC = 15 // Highest processor-specific symbol type
238 // Relocation entry, without explicit addend.
240 Elf32_Addr r_offset; // Location (file byte offset, or program virtual addr)
241 Elf32_Word r_info; // Symbol table index and type of relocation to apply
243 // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE,
244 // and ELF32_R_INFO macros defined in the ELF specification:
245 Elf32_Word getSymbol () const { return (r_info >> 8); }
246 unsigned char getType () const { return (unsigned char) (r_info & 0x0ff); }
247 void setSymbol (Elf32_Word s) { setSymbolAndType (s, getType ()); }
248 void setType (unsigned char t) { setSymbolAndType (getSymbol(), t); }
249 void setSymbolAndType (Elf32_Word s, unsigned char t) {
250 r_info = (s << 8) + t;
254 // Relocation entry with explicit addend.
256 Elf32_Addr r_offset; // Location (file byte offset, or program virtual addr)
257 Elf32_Word r_info; // Symbol table index and type of relocation to apply
258 Elf32_Sword r_addend; // Compute value for relocatable field by adding this
260 // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE,
261 // and ELF32_R_INFO macros defined in the ELF specification:
262 Elf32_Word getSymbol () const { return (r_info >> 8); }
263 unsigned char getType () const { return (unsigned char) (r_info & 0x0ff); }
264 void setSymbol (Elf32_Word s) { setSymbolAndType (s, getType ()); }
265 void setType (unsigned char t) { setSymbolAndType (getSymbol(), t); }
266 void setSymbolAndType (Elf32_Word s, unsigned char t) {
267 r_info = (s << 8) + t;
273 Elf32_Word p_type; // Type of segment
274 Elf32_Off p_offset; // File offset where segment is located, in bytes
275 Elf32_Addr p_vaddr; // Virtual address of beginning of segment
276 Elf32_Addr p_paddr; // Physical address of beginning of segment (OS-specific)
277 Elf32_Word p_filesz; // Num. of bytes in file image of segment (may be zero)
278 Elf32_Word p_memsz; // Num. of bytes in mem image of segment (may be zero)
279 Elf32_Word p_flags; // Segment flags
280 Elf32_Word p_align; // Segment alignment constraint
284 PT_NULL = 0, // Unused segment.
285 PT_LOAD = 1, // Loadable segment.
286 PT_DYNAMIC = 2, // Dynamic linking information.
287 PT_INTERP = 3, // Interpreter pathname.
288 PT_NOTE = 4, // Auxiliary information.
289 PT_SHLIB = 5, // Reserved.
290 PT_PHDR = 6, // The program header table itself.
291 PT_LOPROC = 0x70000000, // Lowest processor-specific program hdr entry type.
292 PT_HIPROC = 0x7fffffff // Highest processor-specific program hdr entry type.
295 } // end namespace ELF
297 } // end namespace llvm