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Diffstat (limited to 'sandbox/src/sidestep/mini_disassembler.h')
-rw-r--r-- | sandbox/src/sidestep/mini_disassembler.h | 156 |
1 files changed, 0 insertions, 156 deletions
diff --git a/sandbox/src/sidestep/mini_disassembler.h b/sandbox/src/sidestep/mini_disassembler.h deleted file mode 100644 index 444df36..0000000 --- a/sandbox/src/sidestep/mini_disassembler.h +++ /dev/null @@ -1,156 +0,0 @@ -// Copyright (c) 2012 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. - -// Definition of MiniDisassembler. - -#ifndef SANDBOX_SRC_SIDESTEP_MINI_DISASSEMBLER_H__ -#define SANDBOX_SRC_SIDESTEP_MINI_DISASSEMBLER_H__ - -#include "sandbox/src/sidestep/mini_disassembler_types.h" - -namespace sidestep { - -// This small disassembler is very limited -// in its functionality, and in fact does only the bare minimum required by the -// preamble patching utility. It may be useful for other purposes, however. -// -// The limitations include at least the following: -// -# No support for coprocessor opcodes, MMX, etc. -// -# No machine-readable identification of opcodes or decoding of -// assembly parameters. The name of the opcode (as a string) is given, -// however, to aid debugging. -// -// You may ask what this little disassembler actually does, then? The answer is -// that it does the following, which is exactly what the patching utility needs: -// -# Indicates if opcode is a jump (any kind) or a return (any kind) -// because this is important for the patching utility to determine if -// a function is too short or there are jumps too early in it for it -// to be preamble patched. -// -# The opcode length is always calculated, so that the patching utility -// can figure out where the next instruction starts, and whether it -// already has enough instructions to replace with the absolute jump -// to the patching code. -// -// The usage is quite simple; just create a MiniDisassembler and use its -// Disassemble() method. -// -// If you would like to extend this disassembler, please refer to the -// IA-32 Intel Architecture Software Developer's Manual Volume 2: -// Instruction Set Reference for information about operand decoding -// etc. -class MiniDisassembler { - public: - - // Creates a new instance and sets defaults. - // - // operand_default_32_bits: If true, the default operand size is - // set to 32 bits, which is the default under Win32. Otherwise it is 16 bits. - // address_default_32_bits: If true, the default address size is - // set to 32 bits, which is the default under Win32. Otherwise it is 16 bits. - MiniDisassembler(bool operand_default_32_bits, - bool address_default_32_bits); - - // Equivalent to MiniDisassembler(true, true); - MiniDisassembler(); - - // Attempts to disassemble a single instruction starting from the - // address in memory it is pointed to. - // - // start: Address where disassembly should start. - // instruction_bytes: Variable that will be incremented by - // the length in bytes of the instruction. - // Returns enItJump, enItReturn or enItGeneric on success. enItUnknown - // if unable to disassemble, enItUnused if this seems to be an unused - // opcode. In the last two (error) cases, cbInstruction will be set - // to 0xffffffff. - // - // Postcondition: This instance of the disassembler is ready to be used again, - // with unchanged defaults from creation time. - InstructionType Disassemble(unsigned char* start, - unsigned int* instruction_bytes); - - private: - - // Makes the disassembler ready for reuse. - void Initialize(); - - // Sets the flags for address and operand sizes. - // Returns Number of prefix bytes. - InstructionType ProcessPrefixes(unsigned char* start, unsigned int* size); - - // Sets the flag for whether we have ModR/M, and increments - // operand_bytes_ if any are specifies by the opcode directly. - // Returns Number of opcode bytes. - InstructionType ProcessOpcode(unsigned char* start, - unsigned int table, - unsigned int* size); - - // Checks the type of the supplied operand. Increments - // operand_bytes_ if it directly indicates an immediate etc. - // operand. Asserts have_modrm_ if the operand specifies - // a ModR/M byte. - bool ProcessOperand(int flag_operand); - - // Increments operand_bytes_ by size specified by ModR/M and - // by SIB if present. - // Returns 0 in case of error, 1 if there is just a ModR/M byte, - // 2 if there is a ModR/M byte and a SIB byte. - bool ProcessModrm(unsigned char* start, unsigned int* size); - - // Processes the SIB byte that it is pointed to. - // start: Pointer to the SIB byte. - // mod: The mod field from the ModR/M byte. - // Returns 1 to indicate success (indicates 1 SIB byte) - bool ProcessSib(unsigned char* start, unsigned char mod, unsigned int* size); - - // The instruction type we have decoded from the opcode. - InstructionType instruction_type_; - - // Counts the number of bytes that is occupied by operands in - // the current instruction (note: we don't care about how large - // operands stored in registers etc. are). - unsigned int operand_bytes_; - - // True iff there is a ModR/M byte in this instruction. - bool have_modrm_; - - // True iff we need to decode the ModR/M byte (sometimes it just - // points to a register, we can tell by the addressing mode). - bool should_decode_modrm_; - - // Current operand size is 32 bits if true, 16 bits if false. - bool operand_is_32_bits_; - - // Default operand size is 32 bits if true, 16 bits if false. - bool operand_default_is_32_bits_; - - // Current address size is 32 bits if true, 16 bits if false. - bool address_is_32_bits_; - - // Default address size is 32 bits if true, 16 bits if false. - bool address_default_is_32_bits_; - - // Huge big opcode table based on the IA-32 manual, defined - // in Ia32OpcodeMap.cpp - static const OpcodeTable s_ia32_opcode_map_[]; - - // Somewhat smaller table to help with decoding ModR/M bytes - // when 16-bit addressing mode is being used. Defined in - // Ia32ModrmMap.cpp - static const ModrmEntry s_ia16_modrm_map_[]; - - // Somewhat smaller table to help with decoding ModR/M bytes - // when 32-bit addressing mode is being used. Defined in - // Ia32ModrmMap.cpp - static const ModrmEntry s_ia32_modrm_map_[]; - - // Indicators of whether we got certain prefixes that certain - // silly Intel instructions depend on in nonstandard ways for - // their behaviors. - bool got_f2_prefix_, got_f3_prefix_, got_66_prefix_; -}; - -}; // namespace sidestep - -#endif // SANDBOX_SRC_SIDESTEP_MINI_DISASSEMBLER_H__ |