lib/Target/X86/Disassembler/X86DisassemblerDecoder.h

   1 /*===- X86DisassemblerDecoderInternal.h - Disassembler decoder -----*- C -*-==*
   2  *
   3  *                     The LLVM Compiler Infrastructure
   4  *
   5  * This file is distributed under the University of Illinois Open Source
   6  * License. See LICENSE.TXT for details.
   7  *
   8  *===----------------------------------------------------------------------===*
   9  *
  10  * This file is part of the X86 Disassembler.
  11  * It contains the public interface of the instruction decoder.
  12  * Documentation for the disassembler can be found in X86Disassembler.h.
  13  *
  14  *===----------------------------------------------------------------------===*/
  15
  16 #ifndef X86DISASSEMBLERDECODER_H
  17 #define X86DISASSEMBLERDECODER_H
  18
  19 #ifdef __cplusplus
  20 extern "C" {
  21 #endif
  22
  23 #define INSTRUCTION_SPECIFIER_FIELDS  \
  24   const char*             name;
  25
  26 #define INSTRUCTION_IDS     \
  27   const InstrUID *instructionIDs;
  28
  29 #include "X86DisassemblerDecoderCommon.h"
  30
  31 #undef INSTRUCTION_SPECIFIER_FIELDS
  32 #undef INSTRUCTION_IDS
  33
  34 /*
  35  * Accessor functions for various fields of an Intel instruction
  36  */
  37 #define modFromModRM(modRM)  ((modRM & 0xc0) >> 6)
  38 #define regFromModRM(modRM)  ((modRM & 0x38) >> 3)
  39 #define rmFromModRM(modRM)   (modRM & 0x7)
  40 #define scaleFromSIB(sib)    ((sib & 0xc0) >> 6)
  41 #define indexFromSIB(sib)    ((sib & 0x38) >> 3)
  42 #define baseFromSIB(sib)     (sib & 0x7)
  43 #define wFromREX(rex)        ((rex & 0x8) >> 3)
  44 #define rFromREX(rex)        ((rex & 0x4) >> 2)
  45 #define xFromREX(rex)        ((rex & 0x2) >> 1)
  46 #define bFromREX(rex)        (rex & 0x1)
  47
  48 /*
  49  * These enums represent Intel registers for use by the decoder.
  50  */
  51
  52 #define REGS_8BIT     \
  53   ENTRY(AL)           \
  54   ENTRY(CL)           \
  55   ENTRY(DL)           \
  56   ENTRY(BL)           \
  57   ENTRY(AH)           \
  58   ENTRY(CH)           \
  59   ENTRY(DH)           \
  60   ENTRY(BH)           \
  61   ENTRY(R8B)          \
  62   ENTRY(R9B)          \
  63   ENTRY(R10B)         \
  64   ENTRY(R11B)         \
  65   ENTRY(R12B)         \
  66   ENTRY(R13B)         \
  67   ENTRY(R14B)         \
  68   ENTRY(R15B)         \
  69   ENTRY(SPL)          \
  70   ENTRY(BPL)          \
  71   ENTRY(SIL)          \
  72   ENTRY(DIL)
  73
  74 #define EA_BASES_16BIT  \
  75   ENTRY(BX_SI)          \
  76   ENTRY(BX_DI)          \
  77   ENTRY(BP_SI)          \
  78   ENTRY(BP_DI)          \
  79   ENTRY(SI)             \
  80   ENTRY(DI)             \
  81   ENTRY(BP)             \
  82   ENTRY(BX)             \
  83   ENTRY(R8W)            \
  84   ENTRY(R9W)            \
  85   ENTRY(R10W)           \
  86   ENTRY(R11W)           \
  87   ENTRY(R12W)           \
  88   ENTRY(R13W)           \
  89   ENTRY(R14W)           \
  90   ENTRY(R15W)
  91
  92 #define REGS_16BIT    \
  93   ENTRY(AX)           \
  94   ENTRY(CX)           \
  95   ENTRY(DX)           \
  96   ENTRY(BX)           \
  97   ENTRY(SP)           \
  98   ENTRY(BP)           \
  99   ENTRY(SI)           \
 100   ENTRY(DI)           \
 101   ENTRY(R8W)          \
 102   ENTRY(R9W)          \
 103   ENTRY(R10W)         \
 104   ENTRY(R11W)         \
 105   ENTRY(R12W)         \
 106   ENTRY(R13W)         \
 107   ENTRY(R14W)         \
 108   ENTRY(R15W)
 109
 110 #define EA_BASES_32BIT  \
 111   ENTRY(EAX)            \
 112   ENTRY(ECX)            \
 113   ENTRY(EDX)            \
 114   ENTRY(EBX)            \
 115   ENTRY(sib)            \
 116   ENTRY(EBP)            \
 117   ENTRY(ESI)            \
 118   ENTRY(EDI)            \
 119   ENTRY(R8D)            \
 120   ENTRY(R9D)            \
 121   ENTRY(R10D)           \
 122   ENTRY(R11D)           \
 123   ENTRY(R12D)           \
 124   ENTRY(R13D)           \
 125   ENTRY(R14D)           \
 126   ENTRY(R15D)
 127
 128 #define REGS_32BIT  \
 129   ENTRY(EAX)        \
 130   ENTRY(ECX)        \
 131   ENTRY(EDX)        \
 132   ENTRY(EBX)        \
 133   ENTRY(ESP)        \
 134   ENTRY(EBP)        \
 135   ENTRY(ESI)        \
 136   ENTRY(EDI)        \
 137   ENTRY(R8D)        \
 138   ENTRY(R9D)        \
 139   ENTRY(R10D)       \
 140   ENTRY(R11D)       \
 141   ENTRY(R12D)       \
 142   ENTRY(R13D)       \
 143   ENTRY(R14D)       \
 144   ENTRY(R15D)
 145
 146 #define EA_BASES_64BIT  \
 147   ENTRY(RAX)            \
 148   ENTRY(RCX)            \
 149   ENTRY(RDX)            \
 150   ENTRY(RBX)            \
 151   ENTRY(sib64)          \
 152   ENTRY(RBP)            \
 153   ENTRY(RSI)            \
 154   ENTRY(RDI)            \
 155   ENTRY(R8)             \
 156   ENTRY(R9)             \
 157   ENTRY(R10)            \
 158   ENTRY(R11)            \
 159   ENTRY(R12)            \
 160   ENTRY(R13)            \
 161   ENTRY(R14)            \
 162   ENTRY(R15)
 163
 164 #define REGS_64BIT  \
 165   ENTRY(RAX)        \
 166   ENTRY(RCX)        \
 167   ENTRY(RDX)        \
 168   ENTRY(RBX)        \
 169   ENTRY(RSP)        \
 170   ENTRY(RBP)        \
 171   ENTRY(RSI)        \
 172   ENTRY(RDI)        \
 173   ENTRY(R8)         \
 174   ENTRY(R9)         \
 175   ENTRY(R10)        \
 176   ENTRY(R11)        \
 177   ENTRY(R12)        \
 178   ENTRY(R13)        \
 179   ENTRY(R14)        \
 180   ENTRY(R15)
 181
 182 #define REGS_MMX  \
 183   ENTRY(MM0)      \
 184   ENTRY(MM1)      \
 185   ENTRY(MM2)      \
 186   ENTRY(MM3)      \
 187   ENTRY(MM4)      \
 188   ENTRY(MM5)      \
 189   ENTRY(MM6)      \
 190   ENTRY(MM7)
 191
 192 #define REGS_XMM  \
 193   ENTRY(XMM0)     \
 194   ENTRY(XMM1)     \
 195   ENTRY(XMM2)     \
 196   ENTRY(XMM3)     \
 197   ENTRY(XMM4)     \
 198   ENTRY(XMM5)     \
 199   ENTRY(XMM6)     \
 200   ENTRY(XMM7)     \
 201   ENTRY(XMM8)     \
 202   ENTRY(XMM9)     \
 203   ENTRY(XMM10)    \
 204   ENTRY(XMM11)    \
 205   ENTRY(XMM12)    \
 206   ENTRY(XMM13)    \
 207   ENTRY(XMM14)    \
 208   ENTRY(XMM15)
 209
 210 #define REGS_SEGMENT \
 211   ENTRY(ES)          \
 212   ENTRY(CS)          \
 213   ENTRY(SS)          \
 214   ENTRY(DS)          \
 215   ENTRY(FS)          \
 216   ENTRY(GS)
 217
 218 #define REGS_DEBUG  \
 219   ENTRY(DR0)        \
 220   ENTRY(DR1)        \
 221   ENTRY(DR2)        \
 222   ENTRY(DR3)        \
 223   ENTRY(DR4)        \
 224   ENTRY(DR5)        \
 225   ENTRY(DR6)        \
 226   ENTRY(DR7)
 227
 228 #define REGS_CONTROL  \
 229   ENTRY(CR0)          \
 230   ENTRY(CR1)          \
 231   ENTRY(CR2)          \
 232   ENTRY(CR3)          \
 233   ENTRY(CR4)          \
 234   ENTRY(CR5)          \
 235   ENTRY(CR6)          \
 236   ENTRY(CR7)          \
 237   ENTRY(CR8)
 238
 239 #define ALL_EA_BASES  \
 240   EA_BASES_16BIT      \
 241   EA_BASES_32BIT      \
 242   EA_BASES_64BIT
 243
 244 #define ALL_SIB_BASES \
 245   REGS_32BIT          \
 246   REGS_64BIT
 247
 248 #define ALL_REGS      \
 249   REGS_8BIT           \
 250   REGS_16BIT          \
 251   REGS_32BIT          \
 252   REGS_64BIT          \
 253   REGS_MMX            \
 254   REGS_XMM            \
 255   REGS_SEGMENT        \
 256   REGS_DEBUG          \
 257   REGS_CONTROL        \
 258   ENTRY(RIP)
 259
 260 /*
 261  * EABase - All possible values of the base field for effective-address
 262  *   computations, a.k.a. the Mod and R/M fields of the ModR/M byte.  We
 263  *   distinguish between bases (EA_BASE_*) and registers that just happen to be
 264  *   referred to when Mod == 0b11 (EA_REG_*).
 265  */
 266 typedef enum {
 267   EA_BASE_NONE,
 268 #define ENTRY(x) EA_BASE_##x,
 269   ALL_EA_BASES
 270 #undef ENTRY
 271 #define ENTRY(x) EA_REG_##x,
 272   ALL_REGS
 273 #undef ENTRY
 274   EA_max
 275 } EABase;
 276
 277 /*
 278  * SIBIndex - All possible values of the SIB index field.
 279  *   Borrows entries from ALL_EA_BASES with the special case that
 280  *   sib is synonymous with NONE.
 281  */
 282 typedef enum {
 283   SIB_INDEX_NONE,
 284 #define ENTRY(x) SIB_INDEX_##x,
 285   ALL_EA_BASES
 286 #undef ENTRY
 287   SIB_INDEX_max
 288 } SIBIndex;
 289
 290 /*
 291  * SIBBase - All possible values of the SIB base field.
 292  */
 293 typedef enum {
 294   SIB_BASE_NONE,
 295 #define ENTRY(x) SIB_BASE_##x,
 296   ALL_SIB_BASES
 297 #undef ENTRY
 298   SIB_BASE_max
 299 } SIBBase;
 300
 301 /*
 302  * EADisplacement - Possible displacement types for effective-address
 303  *   computations.
 304  */
 305 typedef enum {
 306   EA_DISP_NONE,
 307   EA_DISP_8,
 308   EA_DISP_16,
 309   EA_DISP_32
 310 } EADisplacement;
 311
 312 /*
 313  * Reg - All possible values of the reg field in the ModR/M byte.
 314  */
 315 typedef enum {
 316 #define ENTRY(x) MODRM_REG_##x,
 317   ALL_REGS
 318 #undef ENTRY
 319   MODRM_REG_max
 320 } Reg;
 321
 322 /*
 323  * SegmentOverride - All possible segment overrides.
 324  */
 325 typedef enum {
 326   SEG_OVERRIDE_NONE,
 327   SEG_OVERRIDE_CS,
 328   SEG_OVERRIDE_SS,
 329   SEG_OVERRIDE_DS,
 330   SEG_OVERRIDE_ES,
 331   SEG_OVERRIDE_FS,
 332   SEG_OVERRIDE_GS,
 333   SEG_OVERRIDE_max
 334 } SegmentOverride;
 335
 336 typedef uint8_t BOOL;
 337
 338 /*
 339  * byteReader_t - Type for the byte reader that the consumer must provide to
 340  *   the decoder.  Reads a single byte from the instruction's address space.
 341  * @param arg     - A baton that the consumer can associate with any internal
 342  *                  state that it needs.
 343  * @param byte    - A pointer to a single byte in memory that should be set to
 344  *                  contain the value at address.
 345  * @param address - The address in the instruction's address space that should
 346  *                  be read from.
 347  * @return        - -1 if the byte cannot be read for any reason; 0 otherwise.
 348  */
 349 typedef int (*byteReader_t)(void* arg, uint8_t* byte, uint64_t address);
 350
 351 /*
 352  * dlog_t - Type for the logging function that the consumer can provide to
 353  *   get debugging output from the decoder.
 354  * @param arg     - A baton that the consumer can associate with any internal
 355  *                  state that it needs.
 356  * @param log     - A string that contains the message.  Will be reused after
 357  *                  the logger returns.
 358  */
 359 typedef void (*dlog_t)(void* arg, const char *log);
 360
 361 /*
 362  * The x86 internal instruction, which is produced by the decoder.
 363  */
 364 struct InternalInstruction {
 365   /* Reader interface (C) */
 366   byteReader_t reader;
 367   /* Opaque value passed to the reader */
 368   void* readerArg;
 369   /* The address of the next byte to read via the reader */
 370   uint64_t readerCursor;
 371
 372   /* Logger interface (C) */
 373   dlog_t dlog;
 374   /* Opaque value passed to the logger */
 375   void* dlogArg;
 376
 377   /* General instruction information */
 378
 379   /* The mode to disassemble for (64-bit, protected, real) */
 380   DisassemblerMode mode;
 381   /* The start of the instruction, usable with the reader */
 382   uint64_t startLocation;
 383   /* The length of the instruction, in bytes */
 384   size_t length;
 385
 386   /* Prefix state */
 387
 388   /* 1 if the prefix byte corresponding to the entry is present; 0 if not */
 389   uint8_t prefixPresent[0x100];
 390   /* contains the location (for use with the reader) of the prefix byte */
 391   uint64_t prefixLocations[0x100];
 392   /* The value of the REX prefix, if present */
 393   uint8_t rexPrefix;
 394   /* The location of the REX prefix */
 395   uint64_t rexLocation;
 396   /* The location where a mandatory prefix would have to be (i.e., right before
 397      the opcode, or right before the REX prefix if one is present) */
 398   uint64_t necessaryPrefixLocation;
 399   /* The segment override type */
 400   SegmentOverride segmentOverride;
 401
 402   /* Sizes of various critical pieces of data */
 403   uint8_t registerSize;
 404   uint8_t addressSize;
 405   uint8_t displacementSize;
 406   uint8_t immediateSize;
 407
 408   /* opcode state */
 409
 410   /* The value of the two-byte escape prefix (usually 0x0f) */
 411   uint8_t twoByteEscape;
 412   /* The value of the three-byte escape prefix (usually 0x38 or 0x3a) */
 413   uint8_t threeByteEscape;
 414   /* The last byte of the opcode, not counting any ModR/M extension */
 415   uint8_t opcode;
 416   /* The ModR/M byte of the instruction, if it is an opcode extension */
 417   uint8_t modRMExtension;
 418
 419   /* decode state */
 420
 421   /* The type of opcode, used for indexing into the array of decode tables */
 422   OpcodeType opcodeType;
 423   /* The instruction ID, extracted from the decode table */
 424   uint16_t instructionID;
 425   /* The specifier for the instruction, from the instruction info table */
 426   const struct InstructionSpecifier *spec;
 427
 428   /* state for additional bytes, consumed during operand decode.  Pattern:
 429      consumed___ indicates that the byte was already consumed and does not
 430      need to be consumed again */
 431
 432   /* The ModR/M byte, which contains most register operands and some portion of
 433      all memory operands */
 434   BOOL                          consumedModRM;
 435   uint8_t                       modRM;
 436
 437   /* The SIB byte, used for more complex 32- or 64-bit memory operands */
 438   BOOL                          consumedSIB;
 439   uint8_t                       sib;
 440
 441   /* The displacement, used for memory operands */
 442   BOOL                          consumedDisplacement;
 443   int32_t                       displacement;
 444
 445   /* Immediates.  There can be two in some cases */
 446   uint8_t                       numImmediatesConsumed;
 447   uint8_t                       numImmediatesTranslated;
 448   uint64_t                      immediates[2];
 449
 450   /* A register or immediate operand encoded into the opcode */
 451   BOOL                          consumedOpcodeModifier;
 452   uint8_t                       opcodeModifier;
 453   Reg                           opcodeRegister;
 454
 455   /* Portions of the ModR/M byte */
 456
 457   /* These fields determine the allowable values for the ModR/M fields, which
 458      depend on operand and address widths */
 459   EABase                        eaBaseBase;
 460   EABase                        eaRegBase;
 461   Reg                           regBase;
 462
 463   /* The Mod and R/M fields can encode a base for an effective address, or a
 464      register.  These are separated into two fields here */
 465   EABase                        eaBase;
 466   EADisplacement                eaDisplacement;
 467   /* The reg field always encodes a register */
 468   Reg                           reg;
 469
 470   /* SIB state */
 471   SIBIndex                      sibIndex;
 472   uint8_t                       sibScale;
 473   SIBBase                       sibBase;
 474 };
 475
 476 /* decodeInstruction - Decode one instruction and store the decoding results in
 477  *   a buffer provided by the consumer.
 478  * @param insn      - The buffer to store the instruction in.  Allocated by the
 479  *                    consumer.
 480  * @param reader    - The byteReader_t for the bytes to be read.
 481  * @param readerArg - An argument to pass to the reader for storing context
 482  *                    specific to the consumer.  May be NULL.
 483  * @param logger    - The dlog_t to be used in printing status messages from the
 484  *                    disassembler.  May be NULL.
 485  * @param loggerArg - An argument to pass to the logger for storing context
 486  *                    specific to the logger.  May be NULL.
 487  * @param startLoc  - The address (in the reader's address space) of the first
 488  *                    byte in the instruction.
 489  * @param mode      - The mode (16-bit, 32-bit, 64-bit) to decode in.
 490  * @return          - Nonzero if there was an error during decode, 0 otherwise.
 491  */
 492 int decodeInstruction(struct InternalInstruction* insn,
 493                       byteReader_t reader,
 494                       void* readerArg,
 495                       dlog_t logger,
 496                       void* loggerArg,
 497                       uint64_t startLoc,
 498                       DisassemblerMode mode);
 499
 500 /* x86DisassemblerDebug - C-accessible function for printing a message to
 501  *   debugs()
 502  * @param file  - The name of the file printing the debug message.
 503  * @param line  - The line number that printed the debug message.
 504  * @param s     - The message to print.
 505  */
 506
 507 void x86DisassemblerDebug(const char *file,
 508                           unsigned line,
 509                           const char *s);
 510
 511 #ifdef __cplusplus
 512 }
 513 #endif
 514
 515 #endif