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
20extern "C" {
21#endif
22
23#define INSTRUCTION_SPECIFIER_FIELDS \
24  uint16_t operands;
25
26#define INSTRUCTION_IDS     \
27  uint16_t 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  ENTRY(XMM16)    \
224  ENTRY(XMM17)    \
225  ENTRY(XMM18)    \
226  ENTRY(XMM19)    \
227  ENTRY(XMM20)    \
228  ENTRY(XMM21)    \
229  ENTRY(XMM22)    \
230  ENTRY(XMM23)    \
231  ENTRY(XMM24)    \
232  ENTRY(XMM25)    \
233  ENTRY(XMM26)    \
234  ENTRY(XMM27)    \
235  ENTRY(XMM28)    \
236  ENTRY(XMM29)    \
237  ENTRY(XMM30)    \
238  ENTRY(XMM31)
239
240#define REGS_YMM  \
241  ENTRY(YMM0)     \
242  ENTRY(YMM1)     \
243  ENTRY(YMM2)     \
244  ENTRY(YMM3)     \
245  ENTRY(YMM4)     \
246  ENTRY(YMM5)     \
247  ENTRY(YMM6)     \
248  ENTRY(YMM7)     \
249  ENTRY(YMM8)     \
250  ENTRY(YMM9)     \
251  ENTRY(YMM10)    \
252  ENTRY(YMM11)    \
253  ENTRY(YMM12)    \
254  ENTRY(YMM13)    \
255  ENTRY(YMM14)    \
256  ENTRY(YMM15)    \
257  ENTRY(YMM16)    \
258  ENTRY(YMM17)    \
259  ENTRY(YMM18)    \
260  ENTRY(YMM19)    \
261  ENTRY(YMM20)    \
262  ENTRY(YMM21)    \
263  ENTRY(YMM22)    \
264  ENTRY(YMM23)    \
265  ENTRY(YMM24)    \
266  ENTRY(YMM25)    \
267  ENTRY(YMM26)    \
268  ENTRY(YMM27)    \
269  ENTRY(YMM28)    \
270  ENTRY(YMM29)    \
271  ENTRY(YMM30)    \
272  ENTRY(YMM31)
273
274#define REGS_ZMM  \
275  ENTRY(ZMM0)     \
276  ENTRY(ZMM1)     \
277  ENTRY(ZMM2)     \
278  ENTRY(ZMM3)     \
279  ENTRY(ZMM4)     \
280  ENTRY(ZMM5)     \
281  ENTRY(ZMM6)     \
282  ENTRY(ZMM7)     \
283  ENTRY(ZMM8)     \
284  ENTRY(ZMM9)     \
285  ENTRY(ZMM10)    \
286  ENTRY(ZMM11)    \
287  ENTRY(ZMM12)    \
288  ENTRY(ZMM13)    \
289  ENTRY(ZMM14)    \
290  ENTRY(ZMM15)    \
291  ENTRY(ZMM16)    \
292  ENTRY(ZMM17)    \
293  ENTRY(ZMM18)    \
294  ENTRY(ZMM19)    \
295  ENTRY(ZMM20)    \
296  ENTRY(ZMM21)    \
297  ENTRY(ZMM22)    \
298  ENTRY(ZMM23)    \
299  ENTRY(ZMM24)    \
300  ENTRY(ZMM25)    \
301  ENTRY(ZMM26)    \
302  ENTRY(ZMM27)    \
303  ENTRY(ZMM28)    \
304  ENTRY(ZMM29)    \
305  ENTRY(ZMM30)    \
306  ENTRY(ZMM31)
307
308#define REGS_SEGMENT \
309  ENTRY(ES)          \
310  ENTRY(CS)          \
311  ENTRY(SS)          \
312  ENTRY(DS)          \
313  ENTRY(FS)          \
314  ENTRY(GS)
315
316#define REGS_DEBUG  \
317  ENTRY(DR0)        \
318  ENTRY(DR1)        \
319  ENTRY(DR2)        \
320  ENTRY(DR3)        \
321  ENTRY(DR4)        \
322  ENTRY(DR5)        \
323  ENTRY(DR6)        \
324  ENTRY(DR7)
325
326#define REGS_CONTROL  \
327  ENTRY(CR0)          \
328  ENTRY(CR1)          \
329  ENTRY(CR2)          \
330  ENTRY(CR3)          \
331  ENTRY(CR4)          \
332  ENTRY(CR5)          \
333  ENTRY(CR6)          \
334  ENTRY(CR7)          \
335  ENTRY(CR8)
336
337#define ALL_EA_BASES  \
338  EA_BASES_16BIT      \
339  EA_BASES_32BIT      \
340  EA_BASES_64BIT
341
342#define ALL_SIB_BASES \
343  REGS_32BIT          \
344  REGS_64BIT
345
346#define ALL_REGS      \
347  REGS_8BIT           \
348  REGS_16BIT          \
349  REGS_32BIT          \
350  REGS_64BIT          \
351  REGS_MMX            \
352  REGS_XMM            \
353  REGS_YMM            \
354  REGS_ZMM            \
355  REGS_SEGMENT        \
356  REGS_DEBUG          \
357  REGS_CONTROL        \
358  ENTRY(RIP)
359
360/*
361 * EABase - All possible values of the base field for effective-address
362 *   computations, a.k.a. the Mod and R/M fields of the ModR/M byte.  We
363 *   distinguish between bases (EA_BASE_*) and registers that just happen to be
364 *   referred to when Mod == 0b11 (EA_REG_*).
365 */
366typedef enum {
367  EA_BASE_NONE,
368#define ENTRY(x) EA_BASE_##x,
369  ALL_EA_BASES
370#undef ENTRY
371#define ENTRY(x) EA_REG_##x,
372  ALL_REGS
373#undef ENTRY
374  EA_max
375} EABase;
376
377/*
378 * SIBIndex - All possible values of the SIB index field.
379 *   Borrows entries from ALL_EA_BASES with the special case that
380 *   sib is synonymous with NONE.
381 * Vector SIB: index can be XMM or YMM.
382 */
383typedef enum {
384  SIB_INDEX_NONE,
385#define ENTRY(x) SIB_INDEX_##x,
386  ALL_EA_BASES
387  REGS_XMM
388  REGS_YMM
389  REGS_ZMM
390#undef ENTRY
391  SIB_INDEX_max
392} SIBIndex;
393
394/*
395 * SIBBase - All possible values of the SIB base field.
396 */
397typedef enum {
398  SIB_BASE_NONE,
399#define ENTRY(x) SIB_BASE_##x,
400  ALL_SIB_BASES
401#undef ENTRY
402  SIB_BASE_max
403} SIBBase;
404
405/*
406 * EADisplacement - Possible displacement types for effective-address
407 *   computations.
408 */
409typedef enum {
410  EA_DISP_NONE,
411  EA_DISP_8,
412  EA_DISP_16,
413  EA_DISP_32
414} EADisplacement;
415
416/*
417 * Reg - All possible values of the reg field in the ModR/M byte.
418 */
419typedef enum {
420#define ENTRY(x) MODRM_REG_##x,
421  ALL_REGS
422#undef ENTRY
423  MODRM_REG_max
424} Reg;
425
426/*
427 * SegmentOverride - All possible segment overrides.
428 */
429typedef enum {
430  SEG_OVERRIDE_NONE,
431  SEG_OVERRIDE_CS,
432  SEG_OVERRIDE_SS,
433  SEG_OVERRIDE_DS,
434  SEG_OVERRIDE_ES,
435  SEG_OVERRIDE_FS,
436  SEG_OVERRIDE_GS,
437  SEG_OVERRIDE_max
438} SegmentOverride;
439
440/*
441 * VEXLeadingOpcodeByte - Possible values for the VEX.m-mmmm field
442 */
443
444typedef enum {
445  VEX_LOB_0F = 0x1,
446  VEX_LOB_0F38 = 0x2,
447  VEX_LOB_0F3A = 0x3
448} VEXLeadingOpcodeByte;
449
450/*
451 * VEXPrefixCode - Possible values for the VEX.pp field
452 */
453
454typedef enum {
455  VEX_PREFIX_NONE = 0x0,
456  VEX_PREFIX_66 = 0x1,
457  VEX_PREFIX_F3 = 0x2,
458  VEX_PREFIX_F2 = 0x3
459} VEXPrefixCode;
460
461typedef uint8_t BOOL;
462
463/*
464 * byteReader_t - Type for the byte reader that the consumer must provide to
465 *   the decoder.  Reads a single byte from the instruction's address space.
466 * @param arg     - A baton that the consumer can associate with any internal
467 *                  state that it needs.
468 * @param byte    - A pointer to a single byte in memory that should be set to
469 *                  contain the value at address.
470 * @param address - The address in the instruction's address space that should
471 *                  be read from.
472 * @return        - -1 if the byte cannot be read for any reason; 0 otherwise.
473 */
474typedef int (*byteReader_t)(const void* arg, uint8_t* byte, uint64_t address);
475
476/*
477 * dlog_t - Type for the logging function that the consumer can provide to
478 *   get debugging output from the decoder.
479 * @param arg     - A baton that the consumer can associate with any internal
480 *                  state that it needs.
481 * @param log     - A string that contains the message.  Will be reused after
482 *                  the logger returns.
483 */
484typedef void (*dlog_t)(void* arg, const char *log);
485
486/*
487 * The x86 internal instruction, which is produced by the decoder.
488 */
489struct InternalInstruction {
490  /* Reader interface (C) */
491  byteReader_t reader;
492  /* Opaque value passed to the reader */
493  const void* readerArg;
494  /* The address of the next byte to read via the reader */
495  uint64_t readerCursor;
496
497  /* Logger interface (C) */
498  dlog_t dlog;
499  /* Opaque value passed to the logger */
500  void* dlogArg;
501
502  /* General instruction information */
503
504  /* The mode to disassemble for (64-bit, protected, real) */
505  DisassemblerMode mode;
506  /* The start of the instruction, usable with the reader */
507  uint64_t startLocation;
508  /* The length of the instruction, in bytes */
509  size_t length;
510
511  /* Prefix state */
512
513  /* 1 if the prefix byte corresponding to the entry is present; 0 if not */
514  uint8_t prefixPresent[0x100];
515  /* contains the location (for use with the reader) of the prefix byte */
516  uint64_t prefixLocations[0x100];
517  /* The value of the VEX prefix, if present */
518  uint8_t vexPrefix[3];
519  /* The length of the VEX prefix (0 if not present) */
520  uint8_t vexSize;
521  /* The value of the REX prefix, if present */
522  uint8_t rexPrefix;
523  /* The location where a mandatory prefix would have to be (i.e., right before
524     the opcode, or right before the REX prefix if one is present) */
525  uint64_t necessaryPrefixLocation;
526  /* The segment override type */
527  SegmentOverride segmentOverride;
528  /* 1 if the prefix byte, 0xf2 or 0xf3 is xacquire or xrelease */
529  BOOL xAcquireRelease;
530
531  /* Sizes of various critical pieces of data, in bytes */
532  uint8_t registerSize;
533  uint8_t addressSize;
534  uint8_t displacementSize;
535  uint8_t immediateSize;
536
537  /* Offsets from the start of the instruction to the pieces of data, which is
538     needed to find relocation entries for adding symbolic operands */
539  uint8_t displacementOffset;
540  uint8_t immediateOffset;
541
542  /* opcode state */
543
544  /* The value of the two-byte escape prefix (usually 0x0f) */
545  uint8_t twoByteEscape;
546  /* The value of the three-byte escape prefix (usually 0x38 or 0x3a) */
547  uint8_t threeByteEscape;
548  /* The last byte of the opcode, not counting any ModR/M extension */
549  uint8_t opcode;
550  /* The ModR/M byte of the instruction, if it is an opcode extension */
551  uint8_t modRMExtension;
552
553  /* decode state */
554
555  /* The type of opcode, used for indexing into the array of decode tables */
556  OpcodeType opcodeType;
557  /* The instruction ID, extracted from the decode table */
558  uint16_t instructionID;
559  /* The specifier for the instruction, from the instruction info table */
560  const struct InstructionSpecifier *spec;
561
562  /* state for additional bytes, consumed during operand decode.  Pattern:
563     consumed___ indicates that the byte was already consumed and does not
564     need to be consumed again */
565
566  /* The VEX.vvvv field, which contains a third register operand for some AVX
567     instructions */
568  Reg                           vvvv;
569
570  /* The ModR/M byte, which contains most register operands and some portion of
571     all memory operands */
572  BOOL                          consumedModRM;
573  uint8_t                       modRM;
574
575  /* The SIB byte, used for more complex 32- or 64-bit memory operands */
576  BOOL                          consumedSIB;
577  uint8_t                       sib;
578
579  /* The displacement, used for memory operands */
580  BOOL                          consumedDisplacement;
581  int32_t                       displacement;
582
583  /* Immediates.  There can be two in some cases */
584  uint8_t                       numImmediatesConsumed;
585  uint8_t                       numImmediatesTranslated;
586  uint64_t                      immediates[2];
587
588  /* A register or immediate operand encoded into the opcode */
589  BOOL                          consumedOpcodeModifier;
590  uint8_t                       opcodeModifier;
591  Reg                           opcodeRegister;
592
593  /* Portions of the ModR/M byte */
594
595  /* These fields determine the allowable values for the ModR/M fields, which
596     depend on operand and address widths */
597  EABase                        eaBaseBase;
598  EABase                        eaRegBase;
599  Reg                           regBase;
600
601  /* The Mod and R/M fields can encode a base for an effective address, or a
602     register.  These are separated into two fields here */
603  EABase                        eaBase;
604  EADisplacement                eaDisplacement;
605  /* The reg field always encodes a register */
606  Reg                           reg;
607
608  /* SIB state */
609  SIBIndex                      sibIndex;
610  uint8_t                       sibScale;
611  SIBBase                       sibBase;
612
613  const struct OperandSpecifier *operands;
614};
615
616/* decodeInstruction - Decode one instruction and store the decoding results in
617 *   a buffer provided by the consumer.
618 * @param insn      - The buffer to store the instruction in.  Allocated by the
619 *                    consumer.
620 * @param reader    - The byteReader_t for the bytes to be read.
621 * @param readerArg - An argument to pass to the reader for storing context
622 *                    specific to the consumer.  May be NULL.
623 * @param logger    - The dlog_t to be used in printing status messages from the
624 *                    disassembler.  May be NULL.
625 * @param loggerArg - An argument to pass to the logger for storing context
626 *                    specific to the logger.  May be NULL.
627 * @param startLoc  - The address (in the reader's address space) of the first
628 *                    byte in the instruction.
629 * @param mode      - The mode (16-bit, 32-bit, 64-bit) to decode in.
630 * @return          - Nonzero if there was an error during decode, 0 otherwise.
631 */
632int decodeInstruction(struct InternalInstruction* insn,
633                      byteReader_t reader,
634                      const void* readerArg,
635                      dlog_t logger,
636                      void* loggerArg,
637                      const void* miiArg,
638                      uint64_t startLoc,
639                      DisassemblerMode mode);
640
641/* x86DisassemblerDebug - C-accessible function for printing a message to
642 *   debugs()
643 * @param file  - The name of the file printing the debug message.
644 * @param line  - The line number that printed the debug message.
645 * @param s     - The message to print.
646 */
647
648void x86DisassemblerDebug(const char *file,
649                          unsigned line,
650                          const char *s);
651
652const char *x86DisassemblerGetInstrName(unsigned Opcode, const void *mii);
653
654#ifdef __cplusplus
655}
656#endif
657
658#endif
659