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Diffstat (limited to 'trunk/src/windows/mini_disassembler.h')
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diff --git a/trunk/src/windows/mini_disassembler.h b/trunk/src/windows/mini_disassembler.h new file mode 100644 index 0000000..e676232 --- /dev/null +++ b/trunk/src/windows/mini_disassembler.h @@ -0,0 +1,190 @@ +/* Copyright (c) 2007, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * --- + * Author: Joi Sigurdsson + * + * Definition of MiniDisassembler. + */ + +#ifndef GOOGLE_PERFTOOLS_MINI_DISASSEMBLER_H_ +#define GOOGLE_PERFTOOLS_MINI_DISASSEMBLER_H_ + +#include <windows.h> +#include "mini_disassembler_types.h" + +// compatibility shim +#include "base/logging.h" +#define SIDESTEP_ASSERT(cond) RAW_DCHECK(cond, #cond) +#define SIDESTEP_LOG(msg) RAW_VLOG(1, msg) + +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. + // + // @param 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. + // @param 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. + // + // @param start Address where disassembly should start. + // @param instruction_bytes Variable that will be <b>incremented</b> by + // the length in bytes of the instruction. + // @return 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. + // + // @post 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. + // @return 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. + // @return 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. + // @return 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. + // @param start Pointer to the SIB byte. + // @param mod The mod field from the ModR/M byte. + // @return 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.cc + 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.cc + 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.cc + 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 // GOOGLE_PERFTOOLS_MINI_DISASSEMBLER_H_ |