| // Copyright 2007-2009 the V8 project authors. 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. |
| |
| // A Disassembler object is used to disassemble a block of code instruction by |
| // instruction. The default implementation of the NameConverter object can be |
| // overriden to modify register names or to do symbol lookup on addresses. |
| // |
| // The example below will disassemble a block of code and print it to stdout. |
| // |
| // NameConverter converter; |
| // Disassembler d(converter); |
| // for (byte* pc = begin; pc < end;) { |
| // char buffer[128]; |
| // buffer[0] = '\0'; |
| // byte* prev_pc = pc; |
| // pc += d.InstructionDecode(buffer, sizeof buffer, pc); |
| // printf("%p %08x %s\n", |
| // prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer); |
| // } |
| // |
| // The Disassembler class also has a convenience method to disassemble a block |
| // of code into a FILE*, meaning that the above functionality could also be |
| // achieved by just calling Disassembler::Disassemble(stdout, begin, end); |
| |
| |
| #include <assert.h> |
| #include <stdio.h> |
| #include <stdarg.h> |
| #include <string.h> |
| #ifndef WIN32 |
| #include <stdint.h> |
| #endif |
| |
| #include "v8.h" |
| |
| #include "disasm.h" |
| #include "macro-assembler.h" |
| #include "platform.h" |
| |
| |
| namespace assembler { |
| namespace arm { |
| |
| namespace v8i = v8::internal; |
| |
| |
| //------------------------------------------------------------------------------ |
| |
| // Decoder decodes and disassembles instructions into an output buffer. |
| // It uses the converter to convert register names and call destinations into |
| // more informative description. |
| class Decoder { |
| public: |
| Decoder(const disasm::NameConverter& converter, |
| v8::internal::Vector<char> out_buffer) |
| : converter_(converter), |
| out_buffer_(out_buffer), |
| out_buffer_pos_(0) { |
| out_buffer_[out_buffer_pos_] = '\0'; |
| } |
| |
| ~Decoder() {} |
| |
| // Writes one disassembled instruction into 'buffer' (0-terminated). |
| // Returns the length of the disassembled machine instruction in bytes. |
| int InstructionDecode(byte* instruction); |
| |
| private: |
| // Bottleneck functions to print into the out_buffer. |
| void PrintChar(const char ch); |
| void Print(const char* str); |
| |
| // Printing of common values. |
| void PrintRegister(int reg); |
| void PrintCondition(Instr* instr); |
| void PrintShiftRm(Instr* instr); |
| void PrintShiftImm(Instr* instr); |
| void PrintPU(Instr* instr); |
| void PrintSoftwareInterrupt(SoftwareInterruptCodes swi); |
| |
| // Handle formatting of instructions and their options. |
| int FormatRegister(Instr* instr, const char* option); |
| int FormatOption(Instr* instr, const char* option); |
| void Format(Instr* instr, const char* format); |
| void Unknown(Instr* instr); |
| |
| // Each of these functions decodes one particular instruction type, a 3-bit |
| // field in the instruction encoding. |
| // Types 0 and 1 are combined as they are largely the same except for the way |
| // they interpret the shifter operand. |
| void DecodeType01(Instr* instr); |
| void DecodeType2(Instr* instr); |
| void DecodeType3(Instr* instr); |
| void DecodeType4(Instr* instr); |
| void DecodeType5(Instr* instr); |
| void DecodeType6(Instr* instr); |
| void DecodeType7(Instr* instr); |
| void DecodeUnconditional(Instr* instr); |
| |
| const disasm::NameConverter& converter_; |
| v8::internal::Vector<char> out_buffer_; |
| int out_buffer_pos_; |
| |
| DISALLOW_COPY_AND_ASSIGN(Decoder); |
| }; |
| |
| |
| // Support for assertions in the Decoder formatting functions. |
| #define STRING_STARTS_WITH(string, compare_string) \ |
| (strncmp(string, compare_string, strlen(compare_string)) == 0) |
| |
| |
| // Append the ch to the output buffer. |
| void Decoder::PrintChar(const char ch) { |
| out_buffer_[out_buffer_pos_++] = ch; |
| } |
| |
| |
| // Append the str to the output buffer. |
| void Decoder::Print(const char* str) { |
| char cur = *str++; |
| while (cur != '\0' && (out_buffer_pos_ < (out_buffer_.length() - 1))) { |
| PrintChar(cur); |
| cur = *str++; |
| } |
| out_buffer_[out_buffer_pos_] = 0; |
| } |
| |
| |
| // These condition names are defined in a way to match the native disassembler |
| // formatting. See for example the command "objdump -d <binary file>". |
| static const char* cond_names[max_condition] = { |
| "eq", "ne", "cs" , "cc" , "mi" , "pl" , "vs" , "vc" , |
| "hi", "ls", "ge", "lt", "gt", "le", "", "invalid", |
| }; |
| |
| |
| // Print the condition guarding the instruction. |
| void Decoder::PrintCondition(Instr* instr) { |
| Print(cond_names[instr->ConditionField()]); |
| } |
| |
| |
| // Print the register name according to the active name converter. |
| void Decoder::PrintRegister(int reg) { |
| Print(converter_.NameOfCPURegister(reg)); |
| } |
| |
| |
| // These shift names are defined in a way to match the native disassembler |
| // formatting. See for example the command "objdump -d <binary file>". |
| static const char* shift_names[max_shift] = { |
| "lsl", "lsr", "asr", "ror" |
| }; |
| |
| |
| // Print the register shift operands for the instruction. Generally used for |
| // data processing instructions. |
| void Decoder::PrintShiftRm(Instr* instr) { |
| Shift shift = instr->ShiftField(); |
| int shift_amount = instr->ShiftAmountField(); |
| int rm = instr->RmField(); |
| |
| PrintRegister(rm); |
| |
| if ((instr->RegShiftField() == 0) && (shift == LSL) && (shift_amount == 0)) { |
| // Special case for using rm only. |
| return; |
| } |
| if (instr->RegShiftField() == 0) { |
| // by immediate |
| if ((shift == ROR) && (shift_amount == 0)) { |
| Print(", RRX"); |
| return; |
| } else if (((shift == LSR) || (shift == ASR)) && (shift_amount == 0)) { |
| shift_amount = 32; |
| } |
| out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, |
| ", %s #%d", |
| shift_names[shift], shift_amount); |
| } else { |
| // by register |
| int rs = instr->RsField(); |
| out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, |
| ", %s ", shift_names[shift]); |
| PrintRegister(rs); |
| } |
| } |
| |
| |
| // Print the immediate operand for the instruction. Generally used for data |
| // processing instructions. |
| void Decoder::PrintShiftImm(Instr* instr) { |
| int rotate = instr->RotateField() * 2; |
| int immed8 = instr->Immed8Field(); |
| int imm = (immed8 >> rotate) | (immed8 << (32 - rotate)); |
| out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, |
| "#%d", imm); |
| } |
| |
| |
| // Print PU formatting to reduce complexity of FormatOption. |
| void Decoder::PrintPU(Instr* instr) { |
| switch (instr->PUField()) { |
| case 0: { |
| Print("da"); |
| break; |
| } |
| case 1: { |
| Print("ia"); |
| break; |
| } |
| case 2: { |
| Print("db"); |
| break; |
| } |
| case 3: { |
| Print("ib"); |
| break; |
| } |
| default: { |
| UNREACHABLE(); |
| break; |
| } |
| } |
| } |
| |
| |
| // Print SoftwareInterrupt codes. Factoring this out reduces the complexity of |
| // the FormatOption method. |
| void Decoder::PrintSoftwareInterrupt(SoftwareInterruptCodes swi) { |
| switch (swi) { |
| case call_rt_redirected: |
| Print("call_rt_redirected"); |
| return; |
| case break_point: |
| Print("break_point"); |
| return; |
| default: |
| out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, |
| "%d", |
| swi); |
| return; |
| } |
| } |
| |
| |
| // Handle all register based formatting in this function to reduce the |
| // complexity of FormatOption. |
| int Decoder::FormatRegister(Instr* instr, const char* format) { |
| ASSERT(format[0] == 'r'); |
| if (format[1] == 'n') { // 'rn: Rn register |
| int reg = instr->RnField(); |
| PrintRegister(reg); |
| return 2; |
| } else if (format[1] == 'd') { // 'rd: Rd register |
| int reg = instr->RdField(); |
| PrintRegister(reg); |
| return 2; |
| } else if (format[1] == 's') { // 'rs: Rs register |
| int reg = instr->RsField(); |
| PrintRegister(reg); |
| return 2; |
| } else if (format[1] == 'm') { // 'rm: Rm register |
| int reg = instr->RmField(); |
| PrintRegister(reg); |
| return 2; |
| } else if (format[1] == 'l') { |
| // 'rlist: register list for load and store multiple instructions |
| ASSERT(STRING_STARTS_WITH(format, "rlist")); |
| int rlist = instr->RlistField(); |
| int reg = 0; |
| Print("{"); |
| // Print register list in ascending order, by scanning the bit mask. |
| while (rlist != 0) { |
| if ((rlist & 1) != 0) { |
| PrintRegister(reg); |
| if ((rlist >> 1) != 0) { |
| Print(", "); |
| } |
| } |
| reg++; |
| rlist >>= 1; |
| } |
| Print("}"); |
| return 5; |
| } |
| UNREACHABLE(); |
| return -1; |
| } |
| |
| |
| // FormatOption takes a formatting string and interprets it based on |
| // the current instructions. The format string points to the first |
| // character of the option string (the option escape has already been |
| // consumed by the caller.) FormatOption returns the number of |
| // characters that were consumed from the formatting string. |
| int Decoder::FormatOption(Instr* instr, const char* format) { |
| switch (format[0]) { |
| case 'a': { // 'a: accumulate multiplies |
| if (instr->Bit(21) == 0) { |
| Print("ul"); |
| } else { |
| Print("la"); |
| } |
| return 1; |
| } |
| case 'b': { // 'b: byte loads or stores |
| if (instr->HasB()) { |
| Print("b"); |
| } |
| return 1; |
| } |
| case 'c': { // 'cond: conditional execution |
| ASSERT(STRING_STARTS_WITH(format, "cond")); |
| PrintCondition(instr); |
| return 4; |
| } |
| case 'h': { // 'h: halfword operation for extra loads and stores |
| if (instr->HasH()) { |
| Print("h"); |
| } else { |
| Print("b"); |
| } |
| return 1; |
| } |
| case 'l': { // 'l: branch and link |
| if (instr->HasLink()) { |
| Print("l"); |
| } |
| return 1; |
| } |
| case 'm': { |
| if (format[1] == 'e') { // 'memop: load/store instructions |
| ASSERT(STRING_STARTS_WITH(format, "memop")); |
| if (instr->HasL()) { |
| Print("ldr"); |
| } else { |
| Print("str"); |
| } |
| return 5; |
| } |
| // 'msg: for simulator break instructions |
| ASSERT(STRING_STARTS_WITH(format, "msg")); |
| byte* str = |
| reinterpret_cast<byte*>(instr->InstructionBits() & 0x0fffffff); |
| out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, |
| "%s", converter_.NameInCode(str)); |
| return 3; |
| } |
| case 'o': { |
| if (format[3] == '1') { |
| // 'off12: 12-bit offset for load and store instructions |
| ASSERT(STRING_STARTS_WITH(format, "off12")); |
| out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, |
| "%d", instr->Offset12Field()); |
| return 5; |
| } |
| // 'off8: 8-bit offset for extra load and store instructions |
| ASSERT(STRING_STARTS_WITH(format, "off8")); |
| int offs8 = (instr->ImmedHField() << 4) | instr->ImmedLField(); |
| out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, |
| "%d", offs8); |
| return 4; |
| } |
| case 'p': { // 'pu: P and U bits for load and store instructions |
| ASSERT(STRING_STARTS_WITH(format, "pu")); |
| PrintPU(instr); |
| return 2; |
| } |
| case 'r': { |
| return FormatRegister(instr, format); |
| } |
| case 's': { |
| if (format[1] == 'h') { // 'shift_op or 'shift_rm |
| if (format[6] == 'o') { // 'shift_op |
| ASSERT(STRING_STARTS_WITH(format, "shift_op")); |
| if (instr->TypeField() == 0) { |
| PrintShiftRm(instr); |
| } else { |
| ASSERT(instr->TypeField() == 1); |
| PrintShiftImm(instr); |
| } |
| return 8; |
| } else { // 'shift_rm |
| ASSERT(STRING_STARTS_WITH(format, "shift_rm")); |
| PrintShiftRm(instr); |
| return 8; |
| } |
| } else if (format[1] == 'w') { // 'swi |
| ASSERT(STRING_STARTS_WITH(format, "swi")); |
| PrintSoftwareInterrupt(instr->SwiField()); |
| return 3; |
| } else if (format[1] == 'i') { // 'sign: signed extra loads and stores |
| ASSERT(STRING_STARTS_WITH(format, "sign")); |
| if (instr->HasSign()) { |
| Print("s"); |
| } |
| return 4; |
| } |
| // 's: S field of data processing instructions |
| if (instr->HasS()) { |
| Print("s"); |
| } |
| return 1; |
| } |
| case 't': { // 'target: target of branch instructions |
| ASSERT(STRING_STARTS_WITH(format, "target")); |
| int off = (instr->SImmed24Field() << 2) + 8; |
| out_buffer_pos_ += v8i::OS::SNPrintF( |
| out_buffer_ + out_buffer_pos_, |
| "%+d -> %s", |
| off, |
| converter_.NameOfAddress(reinterpret_cast<byte*>(instr) + off)); |
| return 6; |
| } |
| case 'u': { // 'u: signed or unsigned multiplies |
| // The manual gets the meaning of bit 22 backwards in the multiply |
| // instruction overview on page A3.16.2. The instructions that |
| // exist in u and s variants are the following: |
| // smull A4.1.87 |
| // umull A4.1.129 |
| // umlal A4.1.128 |
| // smlal A4.1.76 |
| // For these 0 means u and 1 means s. As can be seen on their individual |
| // pages. The other 18 mul instructions have the bit set or unset in |
| // arbitrary ways that are unrelated to the signedness of the instruction. |
| // None of these 18 instructions exist in both a 'u' and an 's' variant. |
| |
| if (instr->Bit(22) == 0) { |
| Print("u"); |
| } else { |
| Print("s"); |
| } |
| return 1; |
| } |
| case 'w': { // 'w: W field of load and store instructions |
| if (instr->HasW()) { |
| Print("!"); |
| } |
| return 1; |
| } |
| default: { |
| UNREACHABLE(); |
| break; |
| } |
| } |
| UNREACHABLE(); |
| return -1; |
| } |
| |
| |
| // Format takes a formatting string for a whole instruction and prints it into |
| // the output buffer. All escaped options are handed to FormatOption to be |
| // parsed further. |
| void Decoder::Format(Instr* instr, const char* format) { |
| char cur = *format++; |
| while ((cur != 0) && (out_buffer_pos_ < (out_buffer_.length() - 1))) { |
| if (cur == '\'') { // Single quote is used as the formatting escape. |
| format += FormatOption(instr, format); |
| } else { |
| out_buffer_[out_buffer_pos_++] = cur; |
| } |
| cur = *format++; |
| } |
| out_buffer_[out_buffer_pos_] = '\0'; |
| } |
| |
| |
| // For currently unimplemented decodings the disassembler calls Unknown(instr) |
| // which will just print "unknown" of the instruction bits. |
| void Decoder::Unknown(Instr* instr) { |
| Format(instr, "unknown"); |
| } |
| |
| |
| void Decoder::DecodeType01(Instr* instr) { |
| int type = instr->TypeField(); |
| if ((type == 0) && instr->IsSpecialType0()) { |
| // multiply instruction or extra loads and stores |
| if (instr->Bits(7, 4) == 9) { |
| if (instr->Bit(24) == 0) { |
| // multiply instructions |
| if (instr->Bit(23) == 0) { |
| if (instr->Bit(21) == 0) { |
| // The MUL instruction description (A 4.1.33) refers to Rd as being |
| // the destination for the operation, but it confusingly uses the |
| // Rn field to encode it. |
| Format(instr, "mul'cond's 'rn, 'rm, 'rs"); |
| } else { |
| // The MLA instruction description (A 4.1.28) refers to the order |
| // of registers as "Rd, Rm, Rs, Rn". But confusingly it uses the |
| // Rn field to encode the Rd register and the Rd field to encode |
| // the Rn register. |
| Format(instr, "mla'cond's 'rn, 'rm, 'rs, 'rd"); |
| } |
| } else { |
| // The signed/long multiply instructions use the terms RdHi and RdLo |
| // when referring to the target registers. They are mapped to the Rn |
| // and Rd fields as follows: |
| // RdLo == Rd field |
| // RdHi == Rn field |
| // The order of registers is: <RdLo>, <RdHi>, <Rm>, <Rs> |
| Format(instr, "'um'al'cond's 'rd, 'rn, 'rm, 'rs"); |
| } |
| } else { |
| Unknown(instr); // not used by V8 |
| } |
| } else { |
| // extra load/store instructions |
| switch (instr->PUField()) { |
| case 0: { |
| if (instr->Bit(22) == 0) { |
| Format(instr, "'memop'cond'sign'h 'rd, ['rn], -'rm"); |
| } else { |
| Format(instr, "'memop'cond'sign'h 'rd, ['rn], #-'off8"); |
| } |
| break; |
| } |
| case 1: { |
| if (instr->Bit(22) == 0) { |
| Format(instr, "'memop'cond'sign'h 'rd, ['rn], +'rm"); |
| } else { |
| Format(instr, "'memop'cond'sign'h 'rd, ['rn], #+'off8"); |
| } |
| break; |
| } |
| case 2: { |
| if (instr->Bit(22) == 0) { |
| Format(instr, "'memop'cond'sign'h 'rd, ['rn, -'rm]'w"); |
| } else { |
| Format(instr, "'memop'cond'sign'h 'rd, ['rn, #-'off8]'w"); |
| } |
| break; |
| } |
| case 3: { |
| if (instr->Bit(22) == 0) { |
| Format(instr, "'memop'cond'sign'h 'rd, ['rn, +'rm]'w"); |
| } else { |
| Format(instr, "'memop'cond'sign'h 'rd, ['rn, #+'off8]'w"); |
| } |
| break; |
| } |
| default: { |
| // The PU field is a 2-bit field. |
| UNREACHABLE(); |
| break; |
| } |
| } |
| return; |
| } |
| } else { |
| switch (instr->OpcodeField()) { |
| case AND: { |
| Format(instr, "and'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case EOR: { |
| Format(instr, "eor'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case SUB: { |
| Format(instr, "sub'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case RSB: { |
| Format(instr, "rsb'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case ADD: { |
| Format(instr, "add'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case ADC: { |
| Format(instr, "adc'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case SBC: { |
| Format(instr, "sbc'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case RSC: { |
| Format(instr, "rsc'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case TST: { |
| if (instr->HasS()) { |
| Format(instr, "tst'cond 'rn, 'shift_op"); |
| } else { |
| Unknown(instr); // not used by V8 |
| } |
| break; |
| } |
| case TEQ: { |
| if (instr->HasS()) { |
| Format(instr, "teq'cond 'rn, 'shift_op"); |
| } else { |
| switch (instr->Bits(7, 4)) { |
| case BX: |
| Format(instr, "bx'cond 'rm"); |
| break; |
| case BLX: |
| Format(instr, "blx'cond 'rm"); |
| break; |
| default: |
| Unknown(instr); // not used by V8 |
| break; |
| } |
| } |
| break; |
| } |
| case CMP: { |
| if (instr->HasS()) { |
| Format(instr, "cmp'cond 'rn, 'shift_op"); |
| } else { |
| Unknown(instr); // not used by V8 |
| } |
| break; |
| } |
| case CMN: { |
| if (instr->HasS()) { |
| Format(instr, "cmn'cond 'rn, 'shift_op"); |
| } else { |
| switch (instr->Bits(7, 4)) { |
| case CLZ: |
| Format(instr, "clz'cond 'rd, 'rm"); |
| break; |
| default: |
| Unknown(instr); // not used by V8 |
| break; |
| } |
| } |
| break; |
| } |
| case ORR: { |
| Format(instr, "orr'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case MOV: { |
| Format(instr, "mov'cond's 'rd, 'shift_op"); |
| break; |
| } |
| case BIC: { |
| Format(instr, "bic'cond's 'rd, 'rn, 'shift_op"); |
| break; |
| } |
| case MVN: { |
| Format(instr, "mvn'cond's 'rd, 'shift_op"); |
| break; |
| } |
| default: { |
| // The Opcode field is a 4-bit field. |
| UNREACHABLE(); |
| break; |
| } |
| } |
| } |
| } |
| |
| |
| void Decoder::DecodeType2(Instr* instr) { |
| switch (instr->PUField()) { |
| case 0: { |
| if (instr->HasW()) { |
| Unknown(instr); // not used in V8 |
| } |
| Format(instr, "'memop'cond'b 'rd, ['rn], #-'off12"); |
| break; |
| } |
| case 1: { |
| if (instr->HasW()) { |
| Unknown(instr); // not used in V8 |
| } |
| Format(instr, "'memop'cond'b 'rd, ['rn], #+'off12"); |
| break; |
| } |
| case 2: { |
| Format(instr, "'memop'cond'b 'rd, ['rn, #-'off12]'w"); |
| break; |
| } |
| case 3: { |
| Format(instr, "'memop'cond'b 'rd, ['rn, #+'off12]'w"); |
| break; |
| } |
| default: { |
| // The PU field is a 2-bit field. |
| UNREACHABLE(); |
| break; |
| } |
| } |
| } |
| |
| |
| void Decoder::DecodeType3(Instr* instr) { |
| switch (instr->PUField()) { |
| case 0: { |
| ASSERT(!instr->HasW()); |
| Format(instr, "'memop'cond'b 'rd, ['rn], -'shift_rm"); |
| break; |
| } |
| case 1: { |
| ASSERT(!instr->HasW()); |
| Format(instr, "'memop'cond'b 'rd, ['rn], +'shift_rm"); |
| break; |
| } |
| case 2: { |
| Format(instr, "'memop'cond'b 'rd, ['rn, -'shift_rm]'w"); |
| break; |
| } |
| case 3: { |
| Format(instr, "'memop'cond'b 'rd, ['rn, +'shift_rm]'w"); |
| break; |
| } |
| default: { |
| // The PU field is a 2-bit field. |
| UNREACHABLE(); |
| break; |
| } |
| } |
| } |
| |
| |
| void Decoder::DecodeType4(Instr* instr) { |
| ASSERT(instr->Bit(22) == 0); // Privileged mode currently not supported. |
| if (instr->HasL()) { |
| Format(instr, "ldm'cond'pu 'rn'w, 'rlist"); |
| } else { |
| Format(instr, "stm'cond'pu 'rn'w, 'rlist"); |
| } |
| } |
| |
| |
| void Decoder::DecodeType5(Instr* instr) { |
| Format(instr, "b'l'cond 'target"); |
| } |
| |
| |
| void Decoder::DecodeType6(Instr* instr) { |
| // Coprocessor instructions currently not supported. |
| Unknown(instr); |
| } |
| |
| |
| void Decoder::DecodeType7(Instr* instr) { |
| if (instr->Bit(24) == 1) { |
| Format(instr, "swi'cond 'swi"); |
| } else { |
| // Coprocessor instructions currently not supported. |
| Unknown(instr); |
| } |
| } |
| |
| |
| void Decoder::DecodeUnconditional(Instr* instr) { |
| if (instr->Bits(7, 4) == 0xB && instr->Bits(27, 25) == 0 && instr->HasL()) { |
| Format(instr, "'memop'h'pu 'rd, "); |
| bool immediate = instr->HasB(); |
| switch (instr->PUField()) { |
| case 0: { |
| // Post index, negative. |
| if (instr->HasW()) { |
| Unknown(instr); |
| break; |
| } |
| if (immediate) { |
| Format(instr, "['rn], #-'imm12"); |
| } else { |
| Format(instr, "['rn], -'rm"); |
| } |
| break; |
| } |
| case 1: { |
| // Post index, positive. |
| if (instr->HasW()) { |
| Unknown(instr); |
| break; |
| } |
| if (immediate) { |
| Format(instr, "['rn], #+'imm12"); |
| } else { |
| Format(instr, "['rn], +'rm"); |
| } |
| break; |
| } |
| case 2: { |
| // Pre index or offset, negative. |
| if (immediate) { |
| Format(instr, "['rn, #-'imm12]'w"); |
| } else { |
| Format(instr, "['rn, -'rm]'w"); |
| } |
| break; |
| } |
| case 3: { |
| // Pre index or offset, positive. |
| if (immediate) { |
| Format(instr, "['rn, #+'imm12]'w"); |
| } else { |
| Format(instr, "['rn, +'rm]'w"); |
| } |
| break; |
| } |
| default: { |
| // The PU field is a 2-bit field. |
| UNREACHABLE(); |
| break; |
| } |
| } |
| return; |
| } |
| Format(instr, "break 'msg"); |
| } |
| |
| |
| // Disassemble the instruction at *instr_ptr into the output buffer. |
| int Decoder::InstructionDecode(byte* instr_ptr) { |
| Instr* instr = Instr::At(instr_ptr); |
| // Print raw instruction bytes. |
| out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_, |
| "%08x ", |
| instr->InstructionBits()); |
| if (instr->ConditionField() == special_condition) { |
| DecodeUnconditional(instr); |
| return Instr::kInstrSize; |
| } |
| switch (instr->TypeField()) { |
| case 0: |
| case 1: { |
| DecodeType01(instr); |
| break; |
| } |
| case 2: { |
| DecodeType2(instr); |
| break; |
| } |
| case 3: { |
| DecodeType3(instr); |
| break; |
| } |
| case 4: { |
| DecodeType4(instr); |
| break; |
| } |
| case 5: { |
| DecodeType5(instr); |
| break; |
| } |
| case 6: { |
| DecodeType6(instr); |
| break; |
| } |
| case 7: { |
| DecodeType7(instr); |
| break; |
| } |
| default: { |
| // The type field is 3-bits in the ARM encoding. |
| UNREACHABLE(); |
| break; |
| } |
| } |
| return Instr::kInstrSize; |
| } |
| |
| |
| } } // namespace assembler::arm |
| |
| |
| |
| //------------------------------------------------------------------------------ |
| |
| namespace disasm { |
| |
| namespace v8i = v8::internal; |
| |
| |
| static const int kMaxRegisters = 16; |
| |
| // These register names are defined in a way to match the native disassembler |
| // formatting. See for example the command "objdump -d <binary file>". |
| static const char* reg_names[kMaxRegisters] = { |
| "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", |
| "r8", "r9", "r10", "fp", "ip", "sp", "lr", "pc", |
| }; |
| |
| |
| const char* NameConverter::NameOfAddress(byte* addr) const { |
| static v8::internal::EmbeddedVector<char, 32> tmp_buffer; |
| v8::internal::OS::SNPrintF(tmp_buffer, "%p", addr); |
| return tmp_buffer.start(); |
| } |
| |
| |
| const char* NameConverter::NameOfConstant(byte* addr) const { |
| return NameOfAddress(addr); |
| } |
| |
| |
| const char* NameConverter::NameOfCPURegister(int reg) const { |
| const char* result; |
| if ((0 <= reg) && (reg < kMaxRegisters)) { |
| result = reg_names[reg]; |
| } else { |
| result = "noreg"; |
| } |
| return result; |
| } |
| |
| |
| const char* NameConverter::NameOfByteCPURegister(int reg) const { |
| UNREACHABLE(); // ARM does not have the concept of a byte register |
| return "nobytereg"; |
| } |
| |
| |
| const char* NameConverter::NameOfXMMRegister(int reg) const { |
| UNREACHABLE(); // ARM does not have any XMM registers |
| return "noxmmreg"; |
| } |
| |
| |
| const char* NameConverter::NameInCode(byte* addr) const { |
| // The default name converter is called for unknown code. So we will not try |
| // to access any memory. |
| return ""; |
| } |
| |
| |
| //------------------------------------------------------------------------------ |
| |
| Disassembler::Disassembler(const NameConverter& converter) |
| : converter_(converter) {} |
| |
| |
| Disassembler::~Disassembler() {} |
| |
| |
| int Disassembler::InstructionDecode(v8::internal::Vector<char> buffer, |
| byte* instruction) { |
| assembler::arm::Decoder d(converter_, buffer); |
| return d.InstructionDecode(instruction); |
| } |
| |
| |
| int Disassembler::ConstantPoolSizeAt(byte* instruction) { |
| int instruction_bits = *(reinterpret_cast<int*>(instruction)); |
| if ((instruction_bits & 0xfff00000) == 0x03000000) { |
| return instruction_bits & 0x0000ffff; |
| } else { |
| return -1; |
| } |
| } |
| |
| |
| void Disassembler::Disassemble(FILE* f, byte* begin, byte* end) { |
| NameConverter converter; |
| Disassembler d(converter); |
| for (byte* pc = begin; pc < end;) { |
| v8::internal::EmbeddedVector<char, 128> buffer; |
| buffer[0] = '\0'; |
| byte* prev_pc = pc; |
| pc += d.InstructionDecode(buffer, pc); |
| fprintf(f, "%p %08x %s\n", |
| prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer.start()); |
| } |
| } |
| |
| |
| } // namespace disasm |
