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"
32 typedef uint32_t Elf32_Addr; // Program address
33 typedef uint16_t Elf32_Half;
34 typedef uint32_t Elf32_Off; // File offset
35 typedef int32_t Elf32_Sword;
36 typedef uint32_t Elf32_Word;
38 typedef uint64_t Elf64_Addr;
39 typedef uint64_t Elf64_Off;
40 typedef int32_t Elf64_Shalf;
41 typedef int32_t Elf64_Sword;
42 typedef uint32_t Elf64_Word;
43 typedef int64_t Elf64_Sxword;
44 typedef uint64_t Elf64_Xword;
45 typedef uint32_t Elf64_Half;
46 typedef uint16_t Elf64_Quarter;
48 // Object file magic string.
49 static const char ElfMagic[] = { 0x7f, 'E', 'L', 'F', '\0' };
52 unsigned char e_ident[16]; // ELF Identification bytes
53 Elf32_Half e_type; // Type of file (see ET_* below)
54 Elf32_Half e_machine; // Required architecture for this file (see EM_*)
55 Elf32_Word e_version; // Must be equal to 1
56 Elf32_Addr e_entry; // Address to jump to in order to start program
57 Elf32_Off e_phoff; // Program header table's file offset, in bytes
58 Elf32_Off e_shoff; // Section header table's file offset, in bytes
59 Elf32_Word e_flags; // Processor-specific flags
60 Elf32_Half e_ehsize; // Size of ELF header, in bytes
61 Elf32_Half e_phentsize; // Size of an entry in the program header table
62 Elf32_Half e_phnum; // Number of entries in the program header table
63 Elf32_Half e_shentsize; // Size of an entry in the section header table
64 Elf32_Half e_shnum; // Number of entries in the section header table
65 Elf32_Half e_shstrndx; // Sect hdr table index of sect name string table
66 bool checkMagic () const {
67 return (memcmp (e_ident, ElfMagic, strlen (ElfMagic))) == 0;
69 unsigned char getFileClass () const { return e_ident[4]; }
70 unsigned char getDataEncoding () { return e_ident[5]; }
73 // 64-bit ELF header. Fields are the same as for ELF32, but with different
76 unsigned char e_ident[16];
78 Elf64_Quarter e_machine;
84 Elf64_Quarter e_ehsize;
85 Elf64_Quarter e_phentsize;
86 Elf64_Quarter e_phnum;
87 Elf64_Quarter e_shentsize;
88 Elf64_Quarter e_shnum;
89 Elf64_Quarter e_shstrndx;
94 ET_NONE = 0, // No file type
95 ET_REL = 1, // Relocatable file
96 ET_EXEC = 2, // Executable file
97 ET_DYN = 3, // Shared object file
98 ET_CORE = 4, // Core file
99 ET_LOPROC = 0xff00, // Beginning of processor-specific codes
100 ET_HIPROC = 0xffff // Processor-specific
103 // Machine architectures
105 EM_NONE = 0, // No machine
106 EM_M32 = 1, // AT&T WE 32100
107 EM_SPARC = 2, // SPARC
108 EM_386 = 3, // Intel 386
109 EM_68K = 4, // Motorola 68000
110 EM_88K = 5, // Motorola 88000
111 EM_486 = 6, // Intel 486 (deprecated)
112 EM_860 = 7, // Intel 80860
113 EM_MIPS = 8, // MIPS R3000
114 EM_PPC = 20, // PowerPC
116 EM_ALPHA = 41, // DEC Alpha
117 EM_SPARCV9 = 43 // SPARC V9
120 // Object file classes.
122 ELFCLASS32 = 1, // 32-bit object file
123 ELFCLASS64 = 2 // 64-bit object file
126 // Object file byte orderings.
128 ELFDATA2LSB = 1, // Little-endian object file
129 ELFDATA2MSB = 2 // Big-endian object file
134 Elf32_Word sh_name; // Section name (index into string table)
135 Elf32_Word sh_type; // Section type (SHT_*)
136 Elf32_Word sh_flags; // Section flags (SHF_*)
137 Elf32_Addr sh_addr; // Address where section is to be loaded
138 Elf32_Off sh_offset; // File offset of section data, in bytes
139 Elf32_Word sh_size; // Size of section, in bytes
140 Elf32_Word sh_link; // Section type-specific header table index link
141 Elf32_Word sh_info; // Section type-specific extra information
142 Elf32_Word sh_addralign; // Section address alignment
143 Elf32_Word sh_entsize; // Size of records contained within the section
146 // Section header for ELF64 - same fields as ELF32, different types.
150 Elf64_Xword sh_flags;
156 Elf64_Xword sh_addralign;
157 Elf64_Xword sh_entsize;
160 // Special section indices.
162 SHN_UNDEF = 0, // Undefined, missing, irrelevant, or meaningless
163 SHN_LORESERVE = 0xff00, // Lowest reserved index
164 SHN_LOPROC = 0xff00, // Lowest processor-specific index
165 SHN_HIPROC = 0xff1f, // Highest processor-specific index
166 SHN_ABS = 0xfff1, // Symbol has absolute value; does not need relocation
167 SHN_COMMON = 0xfff2, // FORTRAN COMMON or C external global variables
168 SHN_HIRESERVE = 0xffff // Highest reserved index
173 SHT_NULL = 0, // No associated section (inactive entry).
174 SHT_PROGBITS = 1, // Program-defined contents.
175 SHT_SYMTAB = 2, // Symbol table.
176 SHT_STRTAB = 3, // String table.
177 SHT_RELA = 4, // Relocation entries; explicit addends.
178 SHT_HASH = 5, // Symbol hash table.
179 SHT_DYNAMIC = 6, // Information for dynamic linking.
180 SHT_NOTE = 7, // Information about the file.
181 SHT_NOBITS = 8, // Data occupies no space in the file.
182 SHT_REL = 9, // Relocation entries; no explicit addends.
183 SHT_SHLIB = 10, // Reserved.
184 SHT_DYNSYM = 11, // Symbol table.
185 SHT_LOPROC = 0x70000000, // Lowest processor architecture-specific type.
186 SHT_HIPROC = 0x7fffffff, // Highest processor architecture-specific type.
187 SHT_LOUSER = 0x80000000, // Lowest type reserved for applications.
188 SHT_HIUSER = 0xffffffff // Highest type reserved for applications.
193 SHF_WRITE = 0x1, // Section data should be writable during execution.
194 SHF_ALLOC = 0x2, // Section occupies memory during program execution.
195 SHF_EXECINSTR = 0x4, // Section contains executable machine instructions.
196 SHF_MASKPROC = 0xf0000000 // Bits indicating processor-specific flags.
199 // Symbol table entries.
201 Elf32_Word st_name; // Symbol name (index into string table)
202 Elf32_Addr st_value; // Value or address associated with the symbol
203 Elf32_Word st_size; // Size of the symbol
204 unsigned char st_info; // Symbol's type and binding attributes
205 unsigned char st_other; // Must be zero; reserved
206 Elf32_Half st_shndx; // Which section (header table index) it's defined in
208 // These accessors and mutators correspond to the ELF32_ST_BIND,
209 // ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification:
210 unsigned char getBinding () const { return st_info >> 4; }
211 unsigned char getType () const { return st_info & 0x0f; }
212 void setBinding (unsigned char b) { setBindingAndType (b, getType ()); }
213 void setType (unsigned char t) { setBindingAndType (getBinding (), t); }
214 void setBindingAndType (unsigned char b, unsigned char t) {
215 st_info = (b << 4) + (t & 0x0f);
221 STB_LOCAL = 0, // Local symbol, not visible outside obj file containing def
222 STB_GLOBAL = 1, // Global symbol, visible to all object files being combined
223 STB_WEAK = 2, // Weak symbol, like global but lower-precedence
224 STB_LOPROC = 13, // Lowest processor-specific binding type
225 STB_HIPROC = 15 // Highest processor-specific binding type
230 STT_NOTYPE = 0, // Symbol's type is not specified
231 STT_OBJECT = 1, // Symbol is a data object (variable, array, etc.)
232 STT_FUNC = 2, // Symbol is executable code (function, etc.)
233 STT_SECTION = 3, // Symbol refers to a section
234 STT_FILE = 4, // Local, absolute symbol that refers to a file
235 STT_LOPROC = 13, // Lowest processor-specific symbol type
236 STT_HIPROC = 15 // Highest processor-specific symbol type
239 // Relocation entry, without explicit addend.
241 Elf32_Addr r_offset; // Location (file byte offset, or program virtual addr)
242 Elf32_Word r_info; // Symbol table index and type of relocation to apply
244 // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE,
245 // and ELF32_R_INFO macros defined in the ELF specification:
246 Elf32_Word getSymbol () const { return (r_info >> 8); }
247 unsigned char getType () const { return (unsigned char) (r_info & 0x0ff); }
248 void setSymbol (Elf32_Word s) { setSymbolAndType (s, getType ()); }
249 void setType (unsigned char t) { setSymbolAndType (getSymbol(), t); }
250 void setSymbolAndType (Elf32_Word s, unsigned char t) {
251 r_info = (s << 8) + t;
255 // Relocation entry with explicit addend.
257 Elf32_Addr r_offset; // Location (file byte offset, or program virtual addr)
258 Elf32_Word r_info; // Symbol table index and type of relocation to apply
259 Elf32_Sword r_addend; // Compute value for relocatable field by adding this
261 // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE,
262 // and ELF32_R_INFO macros defined in the ELF specification:
263 Elf32_Word getSymbol () const { return (r_info >> 8); }
264 unsigned char getType () const { return (unsigned char) (r_info & 0x0ff); }
265 void setSymbol (Elf32_Word s) { setSymbolAndType (s, getType ()); }
266 void setType (unsigned char t) { setSymbolAndType (getSymbol(), t); }
267 void setSymbolAndType (Elf32_Word s, unsigned char t) {
268 r_info = (s << 8) + t;
274 Elf32_Word p_type; // Type of segment
275 Elf32_Off p_offset; // File offset where segment is located, in bytes
276 Elf32_Addr p_vaddr; // Virtual address of beginning of segment
277 Elf32_Addr p_paddr; // Physical address of beginning of segment (OS-specific)
278 Elf32_Word p_filesz; // Num. of bytes in file image of segment (may be zero)
279 Elf32_Word p_memsz; // Num. of bytes in mem image of segment (may be zero)
280 Elf32_Word p_flags; // Segment flags
281 Elf32_Word p_align; // Segment alignment constraint
285 PT_NULL = 0, // Unused segment.
286 PT_LOAD = 1, // Loadable segment.
287 PT_DYNAMIC = 2, // Dynamic linking information.
288 PT_INTERP = 3, // Interpreter pathname.
289 PT_NOTE = 4, // Auxiliary information.
290 PT_SHLIB = 5, // Reserved.
291 PT_PHDR = 6, // The program header table itself.
292 PT_LOPROC = 0x70000000, // Lowest processor-specific program hdr entry type.
293 PT_HIPROC = 0x7fffffff // Highest processor-specific program hdr entry type.
296 } // end namespace ELF
298 } // end namespace llvm