[Zucchini] Create elf types and utils.

Creates types and utility class to manipulate ELF header format and relocation
references.

BufferView: :modify() was also added.
Change-Id: Iacec212a2fb2f8a6c85d551eed4b8e0a84926d89
Reviewed-on: https://chromium-review.googlesource.com/1136846
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Reviewed-by: Greg Thompson <grt@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578034}
NOKEYCHECK=True
GitOrigin-RevId: 320f7d9d2cff9702e632af296867bf6ce7b14f8b

1 files changed, 252 insertions, 0 deletions

diff --git a/type_elf.h b/type_elf.h
new file mode 100644
index 0000000..99dcba2
--- /dev/null
+++ b/type_elf.h
@@ -0,0 +1,252 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_ZUCCHINI_TYPE_ELF_H_
+#define COMPONENTS_ZUCCHINI_TYPE_ELF_H_
+
+#include <stdint.h>
+
+namespace zucchini {
+
+// Structures and constants taken from linux/elf.h and following identical
+// layout. This is used for parsing of Executable and Linkable Format (ELF).
+namespace elf {
+// Supported by MSVC, g++, and clang++. Ensures no gaps in packing.
+#pragma pack(push, 1)
+
+// This header defines various types from the ELF file spec, but no code
+// related to using them.
+
+typedef uint32_t Elf32_Addr;  // Unsigned program address.
+typedef uint16_t Elf32_Half;  // Unsigned medium integer.
+typedef uint32_t Elf32_Off;   // Unsigned file offset.
+typedef int32_t Elf32_Sword;  // Signed large integer.
+typedef uint32_t Elf32_Word;  // Unsigned large integer.
+
+typedef uint64_t Elf64_Addr;   // Unsigned program address.
+typedef uint16_t Elf64_Half;   // Unsigned medium integer.
+typedef uint64_t Elf64_Off;    // Unsigned file offset.
+typedef int32_t Elf64_Sword;   // Signed large integer.
+typedef uint32_t Elf64_Word;   // Unsigned large integer.
+typedef int64_t Elf64_Sxword;  // Signed extra large integer.
+typedef uint64_t Elf64_Xword;  // Unsigned extra large integer.
+
+// The header at the top of the file.
+struct Elf32_Ehdr {
+  unsigned char e_ident[16];
+  Elf32_Half e_type;
+  Elf32_Half e_machine;
+  Elf32_Word e_version;
+  Elf32_Addr e_entry;
+  Elf32_Off e_phoff;
+  Elf32_Off e_shoff;
+  Elf32_Word e_flags;
+  Elf32_Half e_ehsize;
+  Elf32_Half e_phentsize;
+  Elf32_Half e_phnum;
+  Elf32_Half e_shentsize;
+  Elf32_Half e_shnum;
+  Elf32_Half e_shstrndx;
+};
+
+struct Elf64_Ehdr {
+  unsigned char e_ident[16];
+  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;
+};
+
+// Values for header->e_type.
+enum e_type_values {
+  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,  // Processor-specific
+  ET_HIPROC = 0xFFFF   // Processor-specific
+};
+
+// Values for header->e_machine.
+enum e_machine_values {
+  EM_NONE = 0,       // No machine.
+  EM_386 = 3,        // Intel Architecture.
+  EM_ARM = 40,       // ARM Architecture.
+  EM_X86_64 = 62,    // Intel x86-64 Architecture.
+  EM_AARCH64 = 183,  // ARM Architecture, 64-bit.
+  // Other values skipped.
+};
+
+// A section header in the section header table.
+struct Elf32_Shdr {
+  Elf32_Word sh_name;
+  Elf32_Word sh_type;
+  Elf32_Word sh_flags;
+  Elf32_Addr sh_addr;
+  Elf32_Off sh_offset;
+  Elf32_Word sh_size;
+  Elf32_Word sh_link;
+  Elf32_Word sh_info;
+  Elf32_Word sh_addralign;
+  Elf32_Word sh_entsize;
+};
+
+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;
+};
+
+// Values for the section type field in a section header.
+enum sh_type_values {
+  SHT_NULL = 0,
+  SHT_PROGBITS = 1,
+  SHT_SYMTAB = 2,
+  SHT_STRTAB = 3,
+  SHT_RELA = 4,
+  SHT_HASH = 5,
+  SHT_DYNAMIC = 6,
+  SHT_NOTE = 7,
+  SHT_NOBITS = 8,
+  SHT_REL = 9,
+  SHT_SHLIB = 10,
+  SHT_DYNSYM = 11,
+  SHT_INIT_ARRAY = 14,
+  SHT_FINI_ARRAY = 15,
+  SHT_LOPROC = 0x70000000,
+  SHT_HIPROC = 0x7FFFFFFF,
+  SHT_LOUSER = 0x80000000,
+  SHT_HIUSER = 0xFFFFFFFF
+};
+
+enum sh_flag_masks {
+  SHF_WRITE = 1 << 0,
+  SHF_ALLOC = 1 << 1,
+  SHF_EXECINSTR = 1 << 2,
+};
+
+struct Elf32_Phdr {
+  Elf32_Word p_type;
+  Elf32_Off p_offset;
+  Elf32_Addr p_vaddr;
+  Elf32_Addr p_paddr;
+  Elf32_Word p_filesz;
+  Elf32_Word p_memsz;
+  Elf32_Word p_flags;
+  Elf32_Word p_align;
+};
+
+struct Elf64_Phdr {
+  Elf64_Word p_type;
+  Elf64_Word p_flags;
+  Elf64_Off p_offset;
+  Elf64_Addr p_vaddr;
+  Elf64_Addr p_paddr;
+  Elf64_Xword p_filesz;
+  Elf64_Xword p_memsz;
+  Elf64_Xword p_align;
+};
+
+// Values for the segment type field in a program segment header.
+enum ph_type_values {
+  PT_NULL = 0,
+  PT_LOAD = 1,
+  PT_DYNAMIC = 2,
+  PT_INTERP = 3,
+  PT_NOTE = 4,
+  PT_SHLIB = 5,
+  PT_PHDR = 6,
+  PT_LOPROC = 0x70000000,
+  PT_HIPROC = 0x7FFFFFFF
+};
+
+struct Elf32_Rel {
+  Elf32_Addr r_offset;
+  Elf32_Word r_info;
+};
+
+struct Elf64_Rel {
+  Elf64_Addr r_offset;
+  Elf64_Xword r_info;
+};
+
+struct Elf32_Rela {
+  Elf32_Addr r_offset;
+  Elf32_Word r_info;
+  Elf32_Sword r_addend;
+};
+
+struct Elf64_Rela {
+  Elf64_Addr r_offset;
+  Elf64_Xword r_info;
+  Elf64_Sxword r_addend;
+};
+
+enum elf32_rel_386_type_values {
+  R_386_NONE = 0,
+  R_386_32 = 1,
+  R_386_PC32 = 2,
+  R_386_GOT32 = 3,
+  R_386_PLT32 = 4,
+  R_386_COPY = 5,
+  R_386_GLOB_DAT = 6,
+  R_386_JMP_SLOT = 7,
+  R_386_RELATIVE = 8,
+  R_386_GOTOFF = 9,
+  R_386_GOTPC = 10,
+  R_386_TLS_TPOFF = 14,
+};
+
+enum elf32_rel_x86_64_type_values {
+  R_X86_64_NONE = 0,
+  R_X86_64_64 = 1,
+  R_X86_64_PC32 = 2,
+  R_X86_64_GOT32 = 3,
+  R_X86_64_PLT32 = 4,
+  R_X86_64_COPY = 5,
+  R_X86_64_GLOB_DAT = 6,
+  R_X86_64_JUMP_SLOT = 7,
+  R_X86_64_RELATIVE = 8,
+  R_X86_64_GOTPCREL = 9,
+  R_X86_64_32 = 10,
+  R_X86_64_32S = 11,
+  R_X86_64_16 = 12,
+  R_X86_64_PC16 = 13,
+  R_X86_64_8 = 14,
+  R_X86_64_PC8 = 15,
+};
+
+enum elf32_rel_arm_type_values {
+  R_ARM_RELATIVE = 23,
+};
+
+enum elf64_rel_aarch64_type_values {
+  R_AARCH64_GLOB_DAT = 0x401,
+  R_AARCH64_JUMP_SLOT = 0x402,
+  R_AARCH64_RELATIVE = 0x403,
+};
+
+#pragma pack(pop)
+
+}  // namespace elf
+}  // namespace zucchini
+
+#endif  // COMPONENTS_ZUCCHINI_TYPE_ELF_H_