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 #define rFromVEX2of3(vex)       (((~(vex)) & 0x80) >> 7)
  49 #define xFromVEX2of3(vex)       (((~(vex)) & 0x40) >> 6)
  50 #define bFromVEX2of3(vex)       (((~(vex)) & 0x20) >> 5)
  51 #define mmmmmFromVEX2of3(vex)   ((vex) & 0x1f)
  52 #define wFromVEX3of3(vex)       (((vex) & 0x80) >> 7)
  53 #define vvvvFromVEX3of3(vex)    (((~(vex)) & 0x78) >> 3)
  54 #define lFromVEX3of3(vex)       (((vex) & 0x4) >> 2)
  55 #define ppFromVEX3of3(vex)      ((vex) & 0x3)
  56
  57 #define rFromVEX2of2(vex)       (((~(vex)) & 0x80) >> 7)
  58 #define vvvvFromVEX2of2(vex)    (((~(vex)) & 0x78) >> 3)
  59 #define lFromVEX2of2(vex)       (((vex) & 0x4) >> 2)
  60 #define ppFromVEX2of2(vex)      ((vex) & 0x3)
  61
  62 /*
  63  * These enums represent Intel registers for use by the decoder.
  64  */
  65
  66 #define REGS_8BIT     \
  67   ENTRY(AL)           \
  68   ENTRY(CL)           \
  69   ENTRY(DL)           \
  70   ENTRY(BL)           \
  71   ENTRY(AH)           \
  72   ENTRY(CH)           \
  73   ENTRY(DH)           \
  74   ENTRY(BH)           \
  75   ENTRY(R8B)          \
  76   ENTRY(R9B)          \
  77   ENTRY(R10B)         \
  78   ENTRY(R11B)         \
  79   ENTRY(R12B)         \
  80   ENTRY(R13B)         \
  81   ENTRY(R14B)         \
  82   ENTRY(R15B)         \
  83   ENTRY(SPL)          \
  84   ENTRY(BPL)          \
  85   ENTRY(SIL)          \
  86   ENTRY(DIL)
  87
  88 #define EA_BASES_16BIT  \
  89   ENTRY(BX_SI)          \
  90   ENTRY(BX_DI)          \
  91   ENTRY(BP_SI)          \
  92   ENTRY(BP_DI)          \
  93   ENTRY(SI)             \
  94   ENTRY(DI)             \
  95   ENTRY(BP)             \
  96   ENTRY(BX)             \
  97   ENTRY(R8W)            \
  98   ENTRY(R9W)            \
  99   ENTRY(R10W)           \
 100   ENTRY(R11W)           \
 101   ENTRY(R12W)           \
 102   ENTRY(R13W)           \
 103   ENTRY(R14W)           \
 104   ENTRY(R15W)
 105
 106 #define REGS_16BIT    \
 107   ENTRY(AX)           \
 108   ENTRY(CX)           \
 109   ENTRY(DX)           \
 110   ENTRY(BX)           \
 111   ENTRY(SP)           \
 112   ENTRY(BP)           \
 113   ENTRY(SI)           \
 114   ENTRY(DI)           \
 115   ENTRY(R8W)          \
 116   ENTRY(R9W)          \
 117   ENTRY(R10W)         \
 118   ENTRY(R11W)         \
 119   ENTRY(R12W)         \
 120   ENTRY(R13W)         \
 121   ENTRY(R14W)         \
 122   ENTRY(R15W)
 123
 124 #define EA_BASES_32BIT  \
 125   ENTRY(EAX)            \
 126   ENTRY(ECX)            \
 127   ENTRY(EDX)            \
 128   ENTRY(EBX)            \
 129   ENTRY(sib)            \
 130   ENTRY(EBP)            \
 131   ENTRY(ESI)            \
 132   ENTRY(EDI)            \
 133   ENTRY(R8D)            \
 134   ENTRY(R9D)            \
 135   ENTRY(R10D)           \
 136   ENTRY(R11D)           \
 137   ENTRY(R12D)           \
 138   ENTRY(R13D)           \
 139   ENTRY(R14D)           \
 140   ENTRY(R15D)
 141
 142 #define REGS_32BIT  \
 143   ENTRY(EAX)        \
 144   ENTRY(ECX)        \
 145   ENTRY(EDX)        \
 146   ENTRY(EBX)        \
 147   ENTRY(ESP)        \
 148   ENTRY(EBP)        \
 149   ENTRY(ESI)        \
 150   ENTRY(EDI)        \
 151   ENTRY(R8D)        \
 152   ENTRY(R9D)        \
 153   ENTRY(R10D)       \
 154   ENTRY(R11D)       \
 155   ENTRY(R12D)       \
 156   ENTRY(R13D)       \
 157   ENTRY(R14D)       \
 158   ENTRY(R15D)
 159
 160 #define EA_BASES_64BIT  \
 161   ENTRY(RAX)            \
 162   ENTRY(RCX)            \
 163   ENTRY(RDX)            \
 164   ENTRY(RBX)            \
 165   ENTRY(sib64)          \
 166   ENTRY(RBP)            \
 167   ENTRY(RSI)            \
 168   ENTRY(RDI)            \
 169   ENTRY(R8)             \
 170   ENTRY(R9)             \
 171   ENTRY(R10)            \
 172   ENTRY(R11)            \
 173   ENTRY(R12)            \
 174   ENTRY(R13)            \
 175   ENTRY(R14)            \
 176   ENTRY(R15)
 177
 178 #define REGS_64BIT  \
 179   ENTRY(RAX)        \
 180   ENTRY(RCX)        \
 181   ENTRY(RDX)        \
 182   ENTRY(RBX)        \
 183   ENTRY(RSP)        \
 184   ENTRY(RBP)        \
 185   ENTRY(RSI)        \
 186   ENTRY(RDI)        \
 187   ENTRY(R8)         \
 188   ENTRY(R9)         \
 189   ENTRY(R10)        \
 190   ENTRY(R11)        \
 191   ENTRY(R12)        \
 192   ENTRY(R13)        \
 193   ENTRY(R14)        \
 194   ENTRY(R15)
 195
 196 #define REGS_MMX  \
 197   ENTRY(MM0)      \
 198   ENTRY(MM1)      \
 199   ENTRY(MM2)      \
 200   ENTRY(MM3)      \
 201   ENTRY(MM4)      \
 202   ENTRY(MM5)      \
 203   ENTRY(MM6)      \
 204   ENTRY(MM7)
 205
 206 #define REGS_XMM  \
 207   ENTRY(XMM0)     \
 208   ENTRY(XMM1)     \
 209   ENTRY(XMM2)     \
 210   ENTRY(XMM3)     \
 211   ENTRY(XMM4)     \
 212   ENTRY(XMM5)     \
 213   ENTRY(XMM6)     \
 214   ENTRY(XMM7)     \
 215   ENTRY(XMM8)     \
 216   ENTRY(XMM9)     \
 217   ENTRY(XMM10)    \
 218   ENTRY(XMM11)    \
 219   ENTRY(XMM12)    \
 220   ENTRY(XMM13)    \
 221   ENTRY(XMM14)    \
 222   ENTRY(XMM15)
 223
 224 #define REGS_YMM  \
 225   ENTRY(YMM0)     \
 226   ENTRY(YMM1)     \
 227   ENTRY(YMM2)     \
 228   ENTRY(YMM3)     \
 229   ENTRY(YMM4)     \
 230   ENTRY(YMM5)     \
 231   ENTRY(YMM6)     \
 232   ENTRY(YMM7)     \
 233   ENTRY(YMM8)     \
 234   ENTRY(YMM9)     \
 235   ENTRY(YMM10)    \
 236   ENTRY(YMM11)    \
 237   ENTRY(YMM12)    \
 238   ENTRY(YMM13)    \
 239   ENTRY(YMM14)    \
 240   ENTRY(YMM15)
 241
 242 #define REGS_SEGMENT \
 243   ENTRY(ES)          \
 244   ENTRY(CS)          \
 245   ENTRY(SS)          \
 246   ENTRY(DS)          \
 247   ENTRY(FS)          \
 248   ENTRY(GS)
 249
 250 #define REGS_DEBUG  \
 251   ENTRY(DR0)        \
 252   ENTRY(DR1)        \
 253   ENTRY(DR2)        \
 254   ENTRY(DR3)        \
 255   ENTRY(DR4)        \
 256   ENTRY(DR5)        \
 257   ENTRY(DR6)        \
 258   ENTRY(DR7)
 259
 260 #define REGS_CONTROL  \
 261   ENTRY(CR0)          \
 262   ENTRY(CR1)          \
 263   ENTRY(CR2)          \
 264   ENTRY(CR3)          \
 265   ENTRY(CR4)          \
 266   ENTRY(CR5)          \
 267   ENTRY(CR6)          \
 268   ENTRY(CR7)          \
 269   ENTRY(CR8)
 270
 271 #define ALL_EA_BASES  \
 272   EA_BASES_16BIT      \
 273   EA_BASES_32BIT      \
 274   EA_BASES_64BIT
 275
 276 #define ALL_SIB_BASES \
 277   REGS_32BIT          \
 278   REGS_64BIT
 279
 280 #define ALL_REGS      \
 281   REGS_8BIT           \
 282   REGS_16BIT          \
 283   REGS_32BIT          \
 284   REGS_64BIT          \
 285   REGS_MMX            \
 286   REGS_XMM            \
 287   REGS_YMM            \
 288   REGS_SEGMENT        \
 289   REGS_DEBUG          \
 290   REGS_CONTROL        \
 291   ENTRY(RIP)
 292
 293 /*
 294  * EABase - All possible values of the base field for effective-address
 295  *   computations, a.k.a. the Mod and R/M fields of the ModR/M byte.  We
 296  *   distinguish between bases (EA_BASE_*) and registers that just happen to be
 297  *   referred to when Mod == 0b11 (EA_REG_*).
 298  */
 299 typedef enum {
 300   EA_BASE_NONE,
 301 #define ENTRY(x) EA_BASE_##x,
 302   ALL_EA_BASES
 303 #undef ENTRY
 304 #define ENTRY(x) EA_REG_##x,
 305   ALL_REGS
 306 #undef ENTRY
 307   EA_max
 308 } EABase;
 309
 310 /*
 311  * SIBIndex - All possible values of the SIB index field.
 312  *   Borrows entries from ALL_EA_BASES with the special case that
 313  *   sib is synonymous with NONE.
 314  */
 315 typedef enum {
 316   SIB_INDEX_NONE,
 317 #define ENTRY(x) SIB_INDEX_##x,
 318   ALL_EA_BASES
 319 #undef ENTRY
 320   SIB_INDEX_max
 321 } SIBIndex;
 322
 323 /*
 324  * SIBBase - All possible values of the SIB base field.
 325  */
 326 typedef enum {
 327   SIB_BASE_NONE,
 328 #define ENTRY(x) SIB_BASE_##x,
 329   ALL_SIB_BASES
 330 #undef ENTRY
 331   SIB_BASE_max
 332 } SIBBase;
 333
 334 /*
 335  * EADisplacement - Possible displacement types for effective-address
 336  *   computations.
 337  */
 338 typedef enum {
 339   EA_DISP_NONE,
 340   EA_DISP_8,
 341   EA_DISP_16,
 342   EA_DISP_32
 343 } EADisplacement;
 344
 345 /*
 346  * Reg - All possible values of the reg field in the ModR/M byte.
 347  */
 348 typedef enum {
 349 #define ENTRY(x) MODRM_REG_##x,
 350   ALL_REGS
 351 #undef ENTRY
 352   MODRM_REG_max
 353 } Reg;
 354
 355 /*
 356  * SegmentOverride - All possible segment overrides.
 357  */
 358 typedef enum {
 359   SEG_OVERRIDE_NONE,
 360   SEG_OVERRIDE_CS,
 361   SEG_OVERRIDE_SS,
 362   SEG_OVERRIDE_DS,
 363   SEG_OVERRIDE_ES,
 364   SEG_OVERRIDE_FS,
 365   SEG_OVERRIDE_GS,
 366   SEG_OVERRIDE_max
 367 } SegmentOverride;
 368
 369 /*
 370  * VEXLeadingOpcodeByte - Possible values for the VEX.m-mmmm field
 371  */
 372
 373 typedef enum {
 374   VEX_LOB_0F = 0x1,
 375   VEX_LOB_0F38 = 0x2,
 376   VEX_LOB_0F3A = 0x3
 377 } VEXLeadingOpcodeByte;
 378
 379 /*
 380  * VEXPrefixCode - Possible values for the VEX.pp field
 381  */
 382
 383 typedef enum {
 384   VEX_PREFIX_NONE = 0x0,
 385   VEX_PREFIX_66 = 0x1,
 386   VEX_PREFIX_F3 = 0x2,
 387   VEX_PREFIX_F2 = 0x3
 388 } VEXPrefixCode;
 389
 390 typedef uint8_t BOOL;
 391
 392 /*
 393  * byteReader_t - Type for the byte reader that the consumer must provide to
 394  *   the decoder.  Reads a single byte from the instruction's address space.
 395  * @param arg     - A baton that the consumer can associate with any internal
 396  *                  state that it needs.
 397  * @param byte    - A pointer to a single byte in memory that should be set to
 398  *                  contain the value at address.
 399  * @param address - The address in the instruction's address space that should
 400  *                  be read from.
 401  * @return        - -1 if the byte cannot be read for any reason; 0 otherwise.
 402  */
 403 typedef int (*byteReader_t)(void* arg, uint8_t* byte, uint64_t address);
 404
 405 /*
 406  * dlog_t - Type for the logging function that the consumer can provide to
 407  *   get debugging output from the decoder.
 408  * @param arg     - A baton that the consumer can associate with any internal
 409  *                  state that it needs.
 410  * @param log     - A string that contains the message.  Will be reused after
 411  *                  the logger returns.
 412  */
 413 typedef void (*dlog_t)(void* arg, const char *log);
 414
 415 /*
 416  * The x86 internal instruction, which is produced by the decoder.
 417  */
 418 struct InternalInstruction {
 419   /* Reader interface (C) */
 420   byteReader_t reader;
 421   /* Opaque value passed to the reader */
 422   void* readerArg;
 423   /* The address of the next byte to read via the reader */
 424   uint64_t readerCursor;
 425
 426   /* Logger interface (C) */
 427   dlog_t dlog;
 428   /* Opaque value passed to the logger */
 429   void* dlogArg;
 430
 431   /* General instruction information */
 432
 433   /* The mode to disassemble for (64-bit, protected, real) */
 434   DisassemblerMode mode;
 435   /* The start of the instruction, usable with the reader */
 436   uint64_t startLocation;
 437   /* The length of the instruction, in bytes */
 438   size_t length;
 439
 440   /* Prefix state */
 441
 442   /* 1 if the prefix byte corresponding to the entry is present; 0 if not */
 443   uint8_t prefixPresent[0x100];
 444   /* contains the location (for use with the reader) of the prefix byte */
 445   uint64_t prefixLocations[0x100];
 446   /* The value of the VEX prefix, if present */
 447   uint8_t vexPrefix[3];
 448   /* The length of the VEX prefix (0 if not present) */
 449   uint8_t vexSize;
 450   /* The value of the REX prefix, if present */
 451   uint8_t rexPrefix;
 452   /* The location where a mandatory prefix would have to be (i.e., right before
 453      the opcode, or right before the REX prefix if one is present) */
 454   uint64_t necessaryPrefixLocation;
 455   /* The segment override type */
 456   SegmentOverride segmentOverride;
 457
 458   /* Sizes of various critical pieces of data, in bytes */
 459   uint8_t registerSize;
 460   uint8_t addressSize;
 461   uint8_t displacementSize;
 462   uint8_t immediateSize;
 463
 464   /* opcode state */
 465
 466   /* The value of the two-byte escape prefix (usually 0x0f) */
 467   uint8_t twoByteEscape;
 468   /* The value of the three-byte escape prefix (usually 0x38 or 0x3a) */
 469   uint8_t threeByteEscape;
 470   /* The last byte of the opcode, not counting any ModR/M extension */
 471   uint8_t opcode;
 472   /* The ModR/M byte of the instruction, if it is an opcode extension */
 473   uint8_t modRMExtension;
 474
 475   /* decode state */
 476
 477   /* The type of opcode, used for indexing into the array of decode tables */
 478   OpcodeType opcodeType;
 479   /* The instruction ID, extracted from the decode table */
 480   uint16_t instructionID;
 481   /* The specifier for the instruction, from the instruction info table */
 482   const struct InstructionSpecifier *spec;
 483
 484   /* state for additional bytes, consumed during operand decode.  Pattern:
 485      consumed___ indicates that the byte was already consumed and does not
 486      need to be consumed again */
 487
 488   /* The VEX.vvvv field, which contains a third register operand for some AVX
 489      instructions */
 490   Reg                           vvvv;
 491
 492   /* The ModR/M byte, which contains most register operands and some portion of
 493      all memory operands */
 494   BOOL                          consumedModRM;
 495   uint8_t                       modRM;
 496
 497   /* The SIB byte, used for more complex 32- or 64-bit memory operands */
 498   BOOL                          consumedSIB;
 499   uint8_t                       sib;
 500
 501   /* The displacement, used for memory operands */
 502   BOOL                          consumedDisplacement;
 503   int32_t                       displacement;
 504
 505   /* Immediates.  There can be two in some cases */
 506   uint8_t                       numImmediatesConsumed;
 507   uint8_t                       numImmediatesTranslated;
 508   uint64_t                      immediates[2];
 509
 510   /* A register or immediate operand encoded into the opcode */
 511   BOOL                          consumedOpcodeModifier;
 512   uint8_t                       opcodeModifier;
 513   Reg                           opcodeRegister;
 514
 515   /* Portions of the ModR/M byte */
 516
 517   /* These fields determine the allowable values for the ModR/M fields, which
 518      depend on operand and address widths */
 519   EABase                        eaBaseBase;
 520   EABase                        eaRegBase;
 521   Reg                           regBase;
 522
 523   /* The Mod and R/M fields can encode a base for an effective address, or a
 524      register.  These are separated into two fields here */
 525   EABase                        eaBase;
 526   EADisplacement                eaDisplacement;
 527   /* The reg field always encodes a register */
 528   Reg                           reg;
 529
 530   /* SIB state */
 531   SIBIndex                      sibIndex;
 532   uint8_t                       sibScale;
 533   SIBBase                       sibBase;
 534 };
 535
 536 /* decodeInstruction - Decode one instruction and store the decoding results in
 537  *   a buffer provided by the consumer.
 538  * @param insn      - The buffer to store the instruction in.  Allocated by the
 539  *                    consumer.
 540  * @param reader    - The byteReader_t for the bytes to be read.
 541  * @param readerArg - An argument to pass to the reader for storing context
 542  *                    specific to the consumer.  May be NULL.
 543  * @param logger    - The dlog_t to be used in printing status messages from the
 544  *                    disassembler.  May be NULL.
 545  * @param loggerArg - An argument to pass to the logger for storing context
 546  *                    specific to the logger.  May be NULL.
 547  * @param startLoc  - The address (in the reader's address space) of the first
 548  *                    byte in the instruction.
 549  * @param mode      - The mode (16-bit, 32-bit, 64-bit) to decode in.
 550  * @return          - Nonzero if there was an error during decode, 0 otherwise.
 551  */
 552 int decodeInstruction(struct InternalInstruction* insn,
 553                       byteReader_t reader,
 554                       void* readerArg,
 555                       dlog_t logger,
 556                       void* loggerArg,
 557                       uint64_t startLoc,
 558                       DisassemblerMode mode);
 559
 560 /* x86DisassemblerDebug - C-accessible function for printing a message to
 561  *   debugs()
 562  * @param file  - The name of the file printing the debug message.
 563  * @param line  - The line number that printed the debug message.
 564  * @param s     - The message to print.
 565  */
 566
 567 void x86DisassemblerDebug(const char *file,
 568                           unsigned line,
 569                           const char *s);
 570
 571 #ifdef __cplusplus
 572 }
 573 #endif
 574
 575 #endif