/* Capstone Disassembly Engine */

/* By Nguyen Anh Quynh <aquynh@gmail.com>, 2013-2019 */

/*    Rot127 <unisono@quyllur.org>, 2022-2023 */

#include "Mapping.h"

#include "capstone/capstone.h"

#include "cs_priv.h"

#include "utils.h"

// Create a cache to map LLVM instruction IDs to capstone instruction IDs, if

// the architecture needs this.

cs_err populate_insn_map_cache(cs_struct *handle)

{

  unsigned int i;

  // If this architecture doesn't use instruction mapping, do nothing

  if (!handle->insn_map || handle->insn_map_size <= 0)

    return CS_ERR_OK;

  // Since the instruction map is assumed to be stored in ascending

  // order, we can get the maximum LLVM instruction id just by looking at

  // the last element.

  unsigned int cache_elements =

    handle->insn_map[handle->insn_map_size - 1].id + 1;

  // This should not be initialized yet.

  CS_ASSERT(!handle->insn_cache);

  unsigned short *cache = cs_mem_calloc(cache_elements, sizeof(*cache));

  if (!cache) {

    handle->errnum = CS_ERR_MEM;

    return CS_ERR_MEM;

  }

  handle->insn_cache = cache;

  for (i = 1; i < handle->insn_map_size; ++i)

    handle->insn_cache[handle->insn_map[i].id] = i;

  return CS_ERR_OK;

}

const insn_map *lookup_insn_map(cs_struct *handle, unsigned short id)

{

  // If this is getting called, we need the cache to already be populated

  // (this should be done when populate_insn_map_cache() gets called).

  CS_ASSERT(handle->insn_cache);

  CS_ASSERT(handle->insn_map_size);

  unsigned short highest_id =

    handle->insn_map[handle->insn_map_size - 1].id;

  if (id > highest_id)

    return NULL;

  unsigned short i = handle->insn_cache[id];

  return &handle->insn_map[i];

}

// Gives the id for the given @name if it is saved in @map.

// Returns the id or -1 if not found.

int name2id(const name_map *map, int max, const char *name)

{

  CS_ASSERT_RET_VAL(map && name, -1);

  int i;

  for (i = 0; i < max; i++) {

    if (!map[i].name) {

      return -1;

    }

    if (!strcmp(map[i].name, name)) {

      return map[i].id;

    }

  }

  // nothing match

  return -1;

}

// Gives the name for the given @id if it is saved in @map.

// Returns the name or NULL if not found.

const char *id2name(const name_map *map, int max, const unsigned int id)

{

  int i;

  for (i = 0; i < max; i++) {

    if (map[i].id == id) {

      return map[i].name;

    }

  }

  // nothing match

  return NULL;

}

/// Adds a register to the implicit write register list.

/// It will not add the same register twice.

void map_add_implicit_write(MCInst *MI, uint32_t Reg)

{

  if (!MI->flat_insn->detail)

    return;

  uint16_t *regs_write = MI->flat_insn->detail->regs_write;

  for (int i = 0; i < MAX_IMPL_W_REGS; ++i) {

    if (i == MI->flat_insn->detail->regs_write_count) {

      regs_write[i] = Reg;

      MI->flat_insn->detail->regs_write_count++;

      return;

    }

    if (regs_write[i] == Reg)

      return;

  }

}

/// Adds a register to the implicit read register list.

/// It will not add the same register twice.

void map_add_implicit_read(MCInst *MI, uint32_t Reg)

{

  if (!MI->flat_insn->detail)

    return;

  uint16_t *regs_read = MI->flat_insn->detail->regs_read;

  for (int i = 0; i < MAX_IMPL_R_REGS; ++i) {

    if (i == MI->flat_insn->detail->regs_read_count) {

      regs_read[i] = Reg;

      MI->flat_insn->detail->regs_read_count++;

      return;

    }

    if (regs_read[i] == Reg)

      return;

  }

}

/// Removes a register from the implicit write register list.

void map_remove_implicit_write(MCInst *MI, uint32_t Reg)

{

  if (!MI->flat_insn->detail)

    return;

  uint16_t *regs_write = MI->flat_insn->detail->regs_write;

  bool shorten_list = false;

  for (int i = 0; i < MAX_IMPL_W_REGS; ++i) {

    if (shorten_list) {

      regs_write[i - 1] = regs_write[i];

    }

    if (i >= MI->flat_insn->detail->regs_write_count)

      return;

    if (regs_write[i] == Reg) {

      MI->flat_insn->detail->regs_write_count--;

      // The register should exist only once in the list.

      CS_ASSERT_RET(!shorten_list);

      shorten_list = true;

    }

  }

}

/// Copies the implicit read registers of @imap to @MI->flat_insn.

/// Already present registers will be preserved.

void map_implicit_reads(MCInst *MI, const insn_map *imap)

{

#ifndef CAPSTONE_DIET

  if (!MI->flat_insn->detail)

    return;

  cs_detail *detail = MI->flat_insn->detail;

  unsigned Opcode = MCInst_getOpcode(MI);

  unsigned i = 0;

  uint16_t reg = imap[Opcode].regs_use[i];

  while (reg != 0) {

    if (i >= MAX_IMPL_R_REGS ||

        detail->regs_read_count >= MAX_IMPL_R_REGS) {

      printf("ERROR: Too many implicit read register defined in "

             "instruction mapping.\n");

      return;

    }

    detail->regs_read[detail->regs_read_count++] = reg;

    if (i + 1 < MAX_IMPL_R_REGS) {

      // Select next one

      reg = imap[Opcode].regs_use[++i];

    }

  }

#endif // CAPSTONE_DIET

}

/// Copies the implicit write registers of @imap to @MI->flat_insn.

/// Already present registers will be preserved.

void map_implicit_writes(MCInst *MI, const insn_map *imap)

{

#ifndef CAPSTONE_DIET

  if (!MI->flat_insn->detail)

    return;

  cs_detail *detail = MI->flat_insn->detail;

  unsigned Opcode = MCInst_getOpcode(MI);

  unsigned i = 0;

  uint16_t reg = imap[Opcode].regs_mod[i];

  while (reg != 0) {

    if (i >= MAX_IMPL_W_REGS ||

        detail->regs_write_count >= MAX_IMPL_W_REGS) {

      printf("ERROR: Too many implicit write register defined in "

             "instruction mapping.\n");

      return;

    }

    detail->regs_write[detail->regs_write_count++] = reg;

    if (i + 1 < MAX_IMPL_W_REGS) {

      // Select next one

      reg = imap[Opcode].regs_mod[++i];

    }

  }

#endif // CAPSTONE_DIET

}

/// Adds a given group to @MI->flat_insn.

/// A group is never added twice.

void add_group(MCInst *MI, unsigned /* arch_group */ group)

{

#ifndef CAPSTONE_DIET

  if (!MI->flat_insn->detail)

    return;

  cs_detail *detail = MI->flat_insn->detail;

  if (detail->groups_count >= MAX_NUM_GROUPS) {

    printf("ERROR: Too many groups defined.\n");

    return;

  }

  for (int i = 0; i < detail->groups_count; ++i) {

    if (detail->groups[i] == group) {

      return;

    }

  }

  detail->groups[detail->groups_count++] = group;

#endif // CAPSTONE_DIET

}

/// Copies the groups from @imap to @MI->flat_insn.

/// Already present groups will be preserved.

void map_groups(MCInst *MI, const insn_map *imap)

{

#ifndef CAPSTONE_DIET

  if (!MI->flat_insn->detail)

    return;

  cs_detail *detail = MI->flat_insn->detail;

  unsigned Opcode = MCInst_getOpcode(MI);

  unsigned i = 0;

  uint16_t group = imap[Opcode].groups[i];

  while (group != 0) {

    if (detail->groups_count >= MAX_NUM_GROUPS) {

      printf("ERROR: Too many groups defined in instruction mapping.\n");

      return;

    }

    detail->groups[detail->groups_count++] = group;

    group = imap[Opcode].groups[++i];

  }

#endif // CAPSTONE_DIET

}

/// Returns the pointer to the supllementary information in

/// the instruction mapping table @imap or NULL in case of failure.

const void *map_get_suppl_info(MCInst *MI, const insn_map *imap)

{

#ifndef CAPSTONE_DIET

  if (!MI->flat_insn->detail)

    return NULL;

  unsigned Opcode = MCInst_getOpcode(MI);

  return &imap[Opcode].suppl_info;

#else

  return NULL;

#endif // CAPSTONE_DIET

}

// Search for the CS instruction id for the given @MC_Opcode in @imap.

// return -1 if none is found.

unsigned int find_cs_id(unsigned MC_Opcode, const insn_map *imap,

      unsigned imap_size)

{

  // binary searching since the IDs are sorted in order

  unsigned int left, right, m;

  unsigned int max = imap_size;

  right = max - 1;

  if (MC_Opcode < imap[0].id || MC_Opcode > imap[right].id)

    // not found

    return -1;

  left = 0;

  while (left <= right) {

    m = (left + right) / 2;

    if (MC_Opcode == imap[m].id) {

      return m;

    }

    if (MC_Opcode < imap[m].id)

      right = m - 1;

    else

      left = m + 1;

  }

  return -1;

}

/// Sets the Capstone instruction id which maps to the @MI opcode.

/// If no mapping is found the function returns and prints an error.

void map_cs_id(MCInst *MI, const insn_map *imap, unsigned int imap_size)

{

  unsigned int i = find_cs_id(MCInst_getOpcode(MI), imap, imap_size);

  if (i != -1) {

    MI->flat_insn->id = imap[i].mapid;

    return;

  }

  printf("ERROR: Could not find CS id for MCInst opcode: %d\n",

         MCInst_getOpcode(MI));

  return;

}

/// Returns the operand type information from the

/// mapping table for instruction operands.

/// Only usable by `auto-sync` archs!

const cs_op_type mapping_get_op_type(MCInst *MI, unsigned OpNum,

             const map_insn_ops *insn_ops_map,

             size_t map_size)

{

  assert(MI);

  assert(MI->Opcode < map_size);

  assert(OpNum < sizeof(insn_ops_map[MI->Opcode].ops) /

             sizeof(insn_ops_map[MI->Opcode].ops[0]));

  return insn_ops_map[MI->Opcode].ops[OpNum].type;

}

/// Returns the operand access flags from the

/// mapping table for instruction operands.

/// Only usable by `auto-sync` archs!

const cs_ac_type mapping_get_op_access(MCInst *MI, unsigned OpNum,

               const map_insn_ops *insn_ops_map,

               size_t map_size)

{

  assert(MI);

  assert(MI->Opcode < map_size);

  assert(OpNum < sizeof(insn_ops_map[MI->Opcode].ops) /

             sizeof(insn_ops_map[MI->Opcode].ops[0]));

  cs_ac_type access = insn_ops_map[MI->Opcode].ops[OpNum].access;

  if (MCInst_opIsTied(MI, OpNum) || MCInst_opIsTying(MI, OpNum))

    access |= (access == CS_AC_READ) ? CS_AC_WRITE : CS_AC_READ;

  return access;

}

/// Returns the operand at detail->arch.operands[op_count + offset]

/// Or NULL if detail is not set or the offset would be out of bounds.

#define DEFINE_get_detail_op(arch, ARCH, ARCH_UPPER) \

  cs_##arch##_op *ARCH##_get_detail_op(MCInst *MI, int offset) \

  { \

    if (!MI->flat_insn->detail) \

      return NULL; \

    int OpIdx = MI->flat_insn->detail->arch.op_count + offset; \

    if (OpIdx < 0 || OpIdx >= NUM_##ARCH_UPPER##_OPS) { \

      return NULL; \

    } \

    return &MI->flat_insn->detail->arch.operands[OpIdx]; \

  }

DEFINE_get_detail_op(arm, ARM, ARM);

DEFINE_get_detail_op(ppc, PPC, PPC);

DEFINE_get_detail_op(tricore, TriCore, TRICORE);

DEFINE_get_detail_op(aarch64, AArch64, AARCH64);

DEFINE_get_detail_op(alpha, Alpha, ALPHA);

DEFINE_get_detail_op(hppa, HPPA, HPPA);

DEFINE_get_detail_op(loongarch, LoongArch, LOONGARCH);

DEFINE_get_detail_op(mips, Mips, MIPS);

DEFINE_get_detail_op(riscv, RISCV, RISCV);

DEFINE_get_detail_op(systemz, SystemZ, SYSTEMZ);

DEFINE_get_detail_op(xtensa, Xtensa, XTENSA);

DEFINE_get_detail_op(bpf, BPF, BPF);

DEFINE_get_detail_op(arc, ARC, ARC);

DEFINE_get_detail_op(sparc, Sparc, SPARC);

/// Returns the operand at detail->arch.operands[index]

/// Or NULL if detail is not set or the index would be out of bounds.

#define DEFINE_get_detail_op_at(arch, ARCH, ARCH_UPPER) \

  cs_##arch##_op *ARCH##_get_detail_op_at(MCInst *MI, int index) \

  { \

    if (!MI->flat_insn->detail) \

      return NULL; \

    if (index < 0 || index >= NUM_##ARCH_UPPER##_OPS) { \

      return NULL; \

    } \

    return &MI->flat_insn->detail->arch.operands[index]; \

  }

DEFINE_get_detail_op_at(arm, ARM, ARM);

DEFINE_get_detail_op_at(ppc, PPC, PPC);

DEFINE_get_detail_op_at(tricore, TriCore, TRICORE);

DEFINE_get_detail_op_at(aarch64, AArch64, AARCH64);

DEFINE_get_detail_op_at(alpha, Alpha, ALPHA);

DEFINE_get_detail_op_at(hppa, HPPA, HPPA);

DEFINE_get_detail_op_at(loongarch, LoongArch, LOONGARCH);

DEFINE_get_detail_op_at(mips, Mips, MIPS);

DEFINE_get_detail_op_at(riscv, RISCV, RISCV);

DEFINE_get_detail_op_at(systemz, SystemZ, SYSTEMZ);

DEFINE_get_detail_op_at(xtensa, Xtensa, XTENSA);

DEFINE_get_detail_op_at(bpf, BPF, BPF);

DEFINE_get_detail_op_at(arc, ARC, ARC);

DEFINE_get_detail_op_at(sparc, Sparc, SPARC);

/// Returns true if for this architecture the

/// alias operands should be filled.

/// TODO: Replace this with a proper option.

///       So it can be toggled between disas() calls.

bool map_use_alias_details(const MCInst *MI)

{

  assert(MI);

  return (MI->csh->detail_opt & CS_OPT_ON) &&

         !(MI->csh->detail_opt & CS_OPT_DETAIL_REAL);

}

/// Sets the setDetailOps flag to @p Val.

/// If detail == NULLit refuses to set the flag to true.

void map_set_fill_detail_ops(MCInst *MI, bool Val)

{

  CS_ASSERT_RET(MI);

  if (!detail_is_set(MI)) {

    MI->fillDetailOps = false;

    return;

  }

  MI->fillDetailOps = Val;

}

/// Sets the instruction alias flags and the given alias id.

void map_set_is_alias_insn(MCInst *MI, bool Val, uint64_t Alias)

{

  CS_ASSERT_RET(MI);

  MI->isAliasInstr = Val;

  MI->flat_insn->is_alias = Val;

  MI->flat_insn->alias_id = Alias;

}

static inline bool char_ends_mnem(const char c, cs_arch arch)

{

  switch (arch) {

  default:

    return (!c || c == ' ' || c == '\t' || c == '.');

  case CS_ARCH_PPC:

  case CS_ARCH_RISCV:

    return (!c || c == ' ' || c == '\t');

  case CS_ARCH_SPARC:

    return (!c || c == ' ' || c == '\t' || c == ',');

  }

}

/// Sets an alternative id for some instruction.

/// Or -1 if it fails.

/// You must add (<ARCH>_INS_ALIAS_BEGIN + 1) to the id to get the real id.

void map_set_alias_id(MCInst *MI, const SStream *O,

          const name_map *alias_mnem_id_map, int map_size)

{

  if (!MCInst_isAlias(MI)) {

    MI->flat_insn->alias_id = 0;

    return;

  }

  char alias_mnem[16] = { 0 };

  int i = 0, j = 0;

  const char *asm_str_buf = O->buffer;

  // Skip spaces and tabs

  while (is_blank_char(asm_str_buf[i])) {

    if (!asm_str_buf[i]) {

      MI->flat_insn->alias_id = 0;

      return;

    }

    ++i;

  }

  for (; j < sizeof(alias_mnem) - 1; ++j, ++i) {

    if (char_ends_mnem(asm_str_buf[i], MI->csh->arch))

      break;

    alias_mnem[j] = asm_str_buf[i];

  }

  int alias_id = name2id(alias_mnem_id_map, map_size, alias_mnem);

  MI->flat_insn->alias_id = alias_id < 0 ? 0 : alias_id;

}

/// Does a binary search over the given map and searches for @id.

/// If @id exists in @map, it sets @found to true and returns

/// the value for the @id.

/// Otherwise, @found is set to false and it returns UINT64_MAX.

///

/// Of course it assumes the map is sorted.

uint64_t enum_map_bin_search(const cs_enum_id_map *map, size_t map_len,

           const char *id, bool *found)

{

  size_t l = 0;

  size_t r = map_len;

  size_t id_len = strlen(id);

  while (l <= r) {

    size_t m = (l + r) / 2;

    size_t j = 0;

    size_t i = 0;

    size_t entry_len = strlen(map[m].str);

    while (j < entry_len && i < id_len && id[i] == map[m].str[j]) {

      ++j, ++i;

    }

    if (i == id_len && j == entry_len) {

      *found = true;

      return map[m].val;

    }

    if (id[i] < map[m].str[j]) {

      r = m - 1;

    } else if (id[i] > map[m].str[j]) {

      l = m + 1;

    }

    if ((m == 0 && id[i] < map[m].str[j]) ||

        (l + r) / 2 >= map_len) {

      // Break before we go out of bounds.

      break;

    }

  }

  *found = false;

  return UINT64_MAX;

}