diff options
Diffstat (limited to 'lib/Target/X86/Disassembler/X86Disassembler.cpp')
| -rw-r--r-- | lib/Target/X86/Disassembler/X86Disassembler.cpp | 453 |
1 files changed, 450 insertions, 3 deletions
diff --git a/lib/Target/X86/Disassembler/X86Disassembler.cpp b/lib/Target/X86/Disassembler/X86Disassembler.cpp index 2ebbc9b..a316860 100644 --- a/lib/Target/X86/Disassembler/X86Disassembler.cpp +++ b/lib/Target/X86/Disassembler/X86Disassembler.cpp @@ -6,18 +6,465 @@ // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// +// +// This file is part of the X86 Disassembler. +// It contains code to translate the data produced by the decoder into +// MCInsts. +// Documentation for the disassembler can be found in X86Disassembler.h. +// +//===----------------------------------------------------------------------===// +#include "X86Disassembler.h" +#include "X86DisassemblerDecoder.h" + +#include "llvm/MC/MCDisassembler.h" #include "llvm/MC/MCDisassembler.h" +#include "llvm/MC/MCInst.h" #include "llvm/Target/TargetRegistry.h" -#include "X86.h" +#include "llvm/Support/MemoryObject.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" + +#include "X86GenRegisterNames.inc" + using namespace llvm; +using namespace llvm::X86Disassembler; + +namespace llvm { + +// Fill-ins to make the compiler happy. These constants are never actually +// assigned; they are just filler to make an automatically-generated switch +// statement work. +namespace X86 { + enum { + BX_SI = 500, + BX_DI = 501, + BP_SI = 502, + BP_DI = 503, + sib = 504, + sib64 = 505 + }; +} + +extern Target TheX86_32Target, TheX86_64Target; + +} + +static void translateInstruction(MCInst &target, + InternalInstruction &source); + +X86GenericDisassembler::X86GenericDisassembler(DisassemblerMode mode) : + MCDisassembler(), + fMode(mode) { +} + +X86GenericDisassembler::~X86GenericDisassembler() { +} + +/// regionReader - a callback function that wraps the readByte method from +/// MemoryObject. +/// +/// @param arg - The generic callback parameter. In this case, this should +/// be a pointer to a MemoryObject. +/// @param byte - A pointer to the byte to be read. +/// @param address - The address to be read. +static int regionReader(void* arg, uint8_t* byte, uint64_t address) { + MemoryObject* region = static_cast<MemoryObject*>(arg); + return region->readByte(address, byte); +} + +/// logger - a callback function that wraps the operator<< method from +/// raw_ostream. +/// +/// @param arg - The generic callback parameter. This should be a pointe +/// to a raw_ostream. +/// @param log - A string to be logged. logger() adds a newline. +static void logger(void* arg, const char* log) { + if (!arg) + return; + + raw_ostream &vStream = *(static_cast<raw_ostream*>(arg)); + vStream << log << "\n"; +} + +// +// Public interface for the disassembler +// + +bool X86GenericDisassembler::getInstruction(MCInst &instr, + uint64_t &size, + const MemoryObject ®ion, + uint64_t address, + raw_ostream &vStream) const { + InternalInstruction internalInstr; + + int ret = decodeInstruction(&internalInstr, + regionReader, + (void*)®ion, + logger, + (void*)&vStream, + address, + fMode); + + if(ret) { + size = internalInstr.readerCursor - address; + return false; + } + else { + size = internalInstr.length; + translateInstruction(instr, internalInstr); + return true; + } +} + +// +// Private code that translates from struct InternalInstructions to MCInsts. +// + +/// translateRegister - Translates an internal register to the appropriate LLVM +/// register, and appends it as an operand to an MCInst. +/// +/// @param mcInst - The MCInst to append to. +/// @param reg - The Reg to append. +static void translateRegister(MCInst &mcInst, Reg reg) { +#define ENTRY(x) X86::x, + uint8_t llvmRegnums[] = { + ALL_REGS + 0 + }; +#undef ENTRY + + uint8_t llvmRegnum = llvmRegnums[reg]; + mcInst.addOperand(MCOperand::CreateReg(llvmRegnum)); +} + +/// translateImmediate - Appends an immediate operand to an MCInst. +/// +/// @param mcInst - The MCInst to append to. +/// @param immediate - The immediate value to append. +static void translateImmediate(MCInst &mcInst, uint64_t immediate) { + mcInst.addOperand(MCOperand::CreateImm(immediate)); +} + +/// translateRMRegister - Translates a register stored in the R/M field of the +/// ModR/M byte to its LLVM equivalent and appends it to an MCInst. +/// @param mcInst - The MCInst to append to. +/// @param insn - The internal instruction to extract the R/M field +/// from. +static void translateRMRegister(MCInst &mcInst, + InternalInstruction &insn) { + assert(insn.eaBase != EA_BASE_sib && insn.eaBase != EA_BASE_sib64 && + "A R/M register operand may not have a SIB byte"); + + switch (insn.eaBase) { + case EA_BASE_NONE: + llvm_unreachable("EA_BASE_NONE for ModR/M base"); + break; +#define ENTRY(x) case EA_BASE_##x: + ALL_EA_BASES +#undef ENTRY + llvm_unreachable("A R/M register operand may not have a base; " + "the operand must be a register."); + break; +#define ENTRY(x) \ + case EA_REG_##x: \ + mcInst.addOperand(MCOperand::CreateReg(X86::x)); break; + ALL_REGS +#undef ENTRY + default: + llvm_unreachable("Unexpected EA base register"); + } +} + +/// translateRMMemory - Translates a memory operand stored in the Mod and R/M +/// fields of an internal instruction (and possibly its SIB byte) to a memory +/// operand in LLVM's format, and appends it to an MCInst. +/// +/// @param mcInst - The MCInst to append to. +/// @param insn - The instruction to extract Mod, R/M, and SIB fields +/// from. +/// @param sr - Whether or not to emit the segment register. The +/// LEA instruction does not expect a segment-register +/// operand. +static void translateRMMemory(MCInst &mcInst, + InternalInstruction &insn, + bool sr) { + // Addresses in an MCInst are represented as five operands: + // 1. basereg (register) The R/M base, or (if there is a SIB) the + // SIB base + // 2. scaleamount (immediate) 1, or (if there is a SIB) the specified + // scale amount + // 3. indexreg (register) x86_registerNONE, or (if there is a SIB) + // the index (which is multiplied by the + // scale amount) + // 4. displacement (immediate) 0, or the displacement if there is one + // 5. segmentreg (register) x86_registerNONE for now, but could be set + // if we have segment overrides + + MCOperand baseReg; + MCOperand scaleAmount; + MCOperand indexReg; + MCOperand displacement; + MCOperand segmentReg; + + if (insn.eaBase == EA_BASE_sib || insn.eaBase == EA_BASE_sib64) { + if (insn.sibBase != SIB_BASE_NONE) { + switch (insn.sibBase) { + default: + llvm_unreachable("Unexpected sibBase"); +#define ENTRY(x) \ + case SIB_BASE_##x: \ + baseReg = MCOperand::CreateReg(X86::x); break; + ALL_SIB_BASES +#undef ENTRY + } + } else { + baseReg = MCOperand::CreateReg(0); + } + + if (insn.sibIndex != SIB_INDEX_NONE) { + switch (insn.sibIndex) { + default: + llvm_unreachable("Unexpected sibIndex"); +#define ENTRY(x) \ + case SIB_INDEX_##x: \ + indexReg = MCOperand::CreateReg(X86::x); break; + EA_BASES_32BIT + EA_BASES_64BIT +#undef ENTRY + } + } else { + indexReg = MCOperand::CreateReg(0); + } + + scaleAmount = MCOperand::CreateImm(insn.sibScale); + } else { + switch (insn.eaBase) { + case EA_BASE_NONE: + assert(insn.eaDisplacement != EA_DISP_NONE && + "EA_BASE_NONE and EA_DISP_NONE for ModR/M base"); + + if (insn.mode == MODE_64BIT) + baseReg = MCOperand::CreateReg(X86::RIP); // Section 2.2.1.6 + else + baseReg = MCOperand::CreateReg(0); + + indexReg = MCOperand::CreateReg(0); + break; + case EA_BASE_BX_SI: + baseReg = MCOperand::CreateReg(X86::BX); + indexReg = MCOperand::CreateReg(X86::SI); + break; + case EA_BASE_BX_DI: + baseReg = MCOperand::CreateReg(X86::BX); + indexReg = MCOperand::CreateReg(X86::DI); + break; + case EA_BASE_BP_SI: + baseReg = MCOperand::CreateReg(X86::BP); + indexReg = MCOperand::CreateReg(X86::SI); + break; + case EA_BASE_BP_DI: + baseReg = MCOperand::CreateReg(X86::BP); + indexReg = MCOperand::CreateReg(X86::DI); + break; + default: + indexReg = MCOperand::CreateReg(0); + switch (insn.eaBase) { + default: + llvm_unreachable("Unexpected eaBase"); + break; + // Here, we will use the fill-ins defined above. However, + // BX_SI, BX_DI, BP_SI, and BP_DI are all handled above and + // sib and sib64 were handled in the top-level if, so they're only + // placeholders to keep the compiler happy. +#define ENTRY(x) \ + case EA_BASE_##x: \ + baseReg = MCOperand::CreateReg(X86::x); break; + ALL_EA_BASES +#undef ENTRY +#define ENTRY(x) case EA_REG_##x: + ALL_REGS +#undef ENTRY + llvm_unreachable("A R/M memory operand may not be a register; " + "the base field must be a base."); + break; + } + } + + scaleAmount = MCOperand::CreateImm(1); + } + + displacement = MCOperand::CreateImm(insn.displacement); + + static const uint8_t segmentRegnums[SEG_OVERRIDE_max] = { + 0, // SEG_OVERRIDE_NONE + X86::CS, + X86::SS, + X86::DS, + X86::ES, + X86::FS, + X86::GS + }; + + segmentReg = MCOperand::CreateReg(segmentRegnums[insn.segmentOverride]); + + mcInst.addOperand(baseReg); + mcInst.addOperand(scaleAmount); + mcInst.addOperand(indexReg); + mcInst.addOperand(displacement); + + if (sr) + mcInst.addOperand(segmentReg); +} + +/// translateRM - Translates an operand stored in the R/M (and possibly SIB) +/// byte of an instruction to LLVM form, and appends it to an MCInst. +/// +/// @param mcInst - The MCInst to append to. +/// @param operand - The operand, as stored in the descriptor table. +/// @param insn - The instruction to extract Mod, R/M, and SIB fields +/// from. +static void translateRM(MCInst &mcInst, + OperandSpecifier &operand, + InternalInstruction &insn) { + switch (operand.type) { + default: + llvm_unreachable("Unexpected type for a R/M operand"); + case TYPE_R8: + case TYPE_R16: + case TYPE_R32: + case TYPE_R64: + case TYPE_Rv: + case TYPE_MM: + case TYPE_MM32: + case TYPE_MM64: + case TYPE_XMM: + case TYPE_XMM32: + case TYPE_XMM64: + case TYPE_XMM128: + case TYPE_DEBUGREG: + case TYPE_CR32: + case TYPE_CR64: + translateRMRegister(mcInst, insn); + break; + case TYPE_M: + case TYPE_M8: + case TYPE_M16: + case TYPE_M32: + case TYPE_M64: + case TYPE_M128: + case TYPE_M512: + case TYPE_Mv: + case TYPE_M32FP: + case TYPE_M64FP: + case TYPE_M80FP: + case TYPE_M16INT: + case TYPE_M32INT: + case TYPE_M64INT: + case TYPE_M1616: + case TYPE_M1632: + case TYPE_M1664: + translateRMMemory(mcInst, insn, true); + break; + case TYPE_LEA: + translateRMMemory(mcInst, insn, false); + break; + } +} + +/// translateFPRegister - Translates a stack position on the FPU stack to its +/// LLVM form, and appends it to an MCInst. +/// +/// @param mcInst - The MCInst to append to. +/// @param stackPos - The stack position to translate. +static void translateFPRegister(MCInst &mcInst, + uint8_t stackPos) { + assert(stackPos < 8 && "Invalid FP stack position"); + + mcInst.addOperand(MCOperand::CreateReg(X86::ST0 + stackPos)); +} + +/// translateOperand - Translates an operand stored in an internal instruction +/// to LLVM's format and appends it to an MCInst. +/// +/// @param mcInst - The MCInst to append to. +/// @param operand - The operand, as stored in the descriptor table. +/// @param insn - The internal instruction. +static void translateOperand(MCInst &mcInst, + OperandSpecifier &operand, + InternalInstruction &insn) { + switch (operand.encoding) { + default: + llvm_unreachable("Unhandled operand encoding during translation"); + case ENCODING_REG: + translateRegister(mcInst, insn.reg); + break; + case ENCODING_RM: + translateRM(mcInst, operand, insn); + break; + case ENCODING_CB: + case ENCODING_CW: + case ENCODING_CD: + case ENCODING_CP: + case ENCODING_CO: + case ENCODING_CT: + llvm_unreachable("Translation of code offsets isn't supported."); + case ENCODING_IB: + case ENCODING_IW: + case ENCODING_ID: + case ENCODING_IO: + case ENCODING_Iv: + case ENCODING_Ia: + translateImmediate(mcInst, + insn.immediates[insn.numImmediatesTranslated++]); + break; + case ENCODING_RB: + case ENCODING_RW: + case ENCODING_RD: + case ENCODING_RO: + translateRegister(mcInst, insn.opcodeRegister); + break; + case ENCODING_I: + translateFPRegister(mcInst, insn.opcodeModifier); + break; + case ENCODING_Rv: + translateRegister(mcInst, insn.opcodeRegister); + break; + case ENCODING_DUP: + translateOperand(mcInst, + insn.spec->operands[operand.type - TYPE_DUP0], + insn); + break; + } +} + +/// translateInstruction - Translates an internal instruction and all its +/// operands to an MCInst. +/// +/// @param mcInst - The MCInst to populate with the instruction's data. +/// @param insn - The internal instruction. +static void translateInstruction(MCInst &mcInst, + InternalInstruction &insn) { + assert(insn.spec); + + mcInst.setOpcode(insn.instructionID); + + int index; + + insn.numImmediatesTranslated = 0; + + for (index = 0; index < X86_MAX_OPERANDS; ++index) { + if (insn.spec->operands[index].encoding != ENCODING_NONE) + translateOperand(mcInst, insn.spec->operands[index], insn); + } +} static const MCDisassembler *createX86_32Disassembler(const Target &T) { - return 0; + return new X86Disassembler::X86_32Disassembler; } static const MCDisassembler *createX86_64Disassembler(const Target &T) { - return 0; + return new X86Disassembler::X86_64Disassembler; } extern "C" void LLVMInitializeX86Disassembler() { |
