ljitlib.c

lua的即时编译器。支持lua 5.1.2版本

  lua_pushvalue(L, -2);  /* Pipeline table as upvalue. */
  lua_pushcclosure(L, j_frontend, 1);
  lua_rawset(L, LUA_REGISTRYINDEX);

  /* Register the frontend wrapper. */
  G(L)->jit_state->frontwrap = frontwrap;

  /* Add jit.attach with the pipeline table as upvalue. */
  lua_pushcclosure(L, j_attach, 1);
  lua_setfield(L, -2, "attach");  /* "jit" table must be below. */
}

/* ------------------------------------------------------------------------ */

/* Calculate total mcode size without mfm and only for active mcode blocks. */
static size_t mcodesize(Proto *pt)
{
  jit_MCTrailer tr;
  size_t sz = 0;
  tr.mcode = (char *)pt->jit_mcode;
  tr.sz = pt->jit_szmcode;
  do {
    jit_Mfm *mfm = JIT_MCMFM(tr.mcode, tr.sz);
    if (sz != 0 && jit_mfm_ismain(mfm)) break;  /* Stop at old main mfm. */
    while (*mfm != JIT_MFM_STOP) mfm--;  /* Search for end of mcode. */
    sz += (char *)mfm-(char *)tr.mcode;  /* Add size of mcode without mfm. */
    memcpy((void *)&tr, JIT_MCTRAILER(tr.mcode, tr.sz), sizeof(jit_MCTrailer));
  } while (tr.mcode != NULL);
  return sz;
}

#define setintfield(name, i) \
  do { lua_pushinteger(L, i); lua_setfield(L, -2, name); } while (0)

/* local stats = jit.util.stats(func) */
static int ju_stats(lua_State *L)
{
  if (!(L->top > L->base))
    luaL_argerror(L, 1, "Lua function expected");
  if (isLfunction(L->base)) {
    Proto *pt = clvalue(L->base)->l.p;
    lua_createtable(L, 0, 11);
    setintfield("status", pt->jit_status);
    setintfield("stackslots", pt->maxstacksize);
    setintfield("params", pt->numparams);
    setintfield("bytecodes", pt->sizecode);
    setintfield("consts", pt->sizek);
    setintfield("upvalues", pt->nups);
    setintfield("subs", pt->sizep);
    lua_pushboolean(L, pt->is_vararg);
    lua_setfield(L, -2, "isvararg");
    lua_getfenv(L, 1);
    lua_setfield(L, -2, "env");
    if (pt->jit_szmcode != 0) {
      setintfield("mcodesize", (int)mcodesize(pt));
      lua_pushnumber(L, (lua_Number)(size_t)pt->jit_mcode);
      lua_setfield(L, -2, "mcodeaddr");
    }
    return 1;
  } else {
    return 0;  /* Don't throw an error like the other util functions. */
  }
}

/* local op, a, b, c, test = jit.util.bytecode(func, pc) */
static int ju_bytecode(lua_State *L)
{
  Proto *pt = check_LCL(L)->l.p;
  int pc = luaL_checkint(L, 2);
  if (pc >= 1 && pc <= pt->sizecode) {
    Instruction ins = pt->code[pc-1];
    OpCode op = GET_OPCODE(ins);
    if (pc > 1 && (((int)OP_SETLIST) << POS_OP) ==
	(pt->code[pc-2] & (MASK1(SIZE_OP,POS_OP) | MASK1(SIZE_C,POS_C)))) {
      lua_pushstring(L, luaP_opnames[OP_SETLIST]);
      lua_pushnumber(L, (lua_Number)ins);  /* Fake extended op. */
      return 1;
    }
    if (op >= NUM_OPCODES) return 0;  /* Just in case. */
    lua_pushstring(L, luaP_opnames[op]);
    lua_pushinteger(L, GETARG_A(ins));
    switch (getOpMode(op)) {
    case iABC: {
      int b = GETARG_B(ins), c = GETARG_C(ins);
      switch (getBMode(op)) {
      case OpArgN: lua_pushnil(L); break;
      case OpArgK: if (ISK(b)) b = -1-INDEXK(b);
      case OpArgR: case OpArgU: lua_pushinteger(L, b); break;
      }
      switch (getCMode(op)) {
      case OpArgN: lua_pushnil(L); break;
      case OpArgK: if (ISK(c)) c = -1-INDEXK(c);
      case OpArgR: case OpArgU: lua_pushinteger(L, c); break;
      }
      lua_pushboolean(L, testTMode(op));
      return 5;
    }
    case iABx: {
      int bx = GETARG_Bx(ins);
      lua_pushinteger(L, getBMode(op) == OpArgK ? -1-bx : bx);
      return 3;
    }
    case iAsBx:
      lua_pushinteger(L, GETARG_sBx(ins));
      return 3;
    }
  }
  return 0;
}

/* local const, ok = jit.util.const(func, idx) */
static int ju_const(lua_State *L)
{
  Proto *pt = check_LCL(L)->l.p;
  int idx = luaL_checkint(L, 2);
  if (idx < 0) idx = -idx;  /* Handle both positive and negative indices. */
  if (idx >= 1 && idx <= pt->sizek) {
    setobj2s(L, L->top-1, &pt->k[idx-1]);
    lua_pushboolean(L, 1);
    return 2;
  }
  lua_pushnil(L);
  lua_pushboolean(L, 0);
  return 2;
}

/* local upvalue, ok = jit.util.upvalue(func, idx) */
static int ju_upvalue(lua_State *L)
{
  Closure *cl = check_LCL(L);
  Proto *pt = cl->l.p;
  int idx = luaL_checkint(L, 2);
  if (idx >= 0 && idx < pt->nups) {
    setobj2s(L, L->top-1, cl->l.upvals[idx]->v);
    lua_pushboolean(L, 1);
    return 2;
  }
  lua_pushnil(L);
  lua_pushboolean(L, 0);
  return 2;
}

/* local nup = jit.util.closurenup(func, idx) */
static int ju_closurenup(lua_State *L)
{
  Closure *cl = check_LCL(L);
  Proto *pt = cl->l.p;
  int idx = luaL_checkint(L, 2);
  if (idx >= 0 && idx < pt->sizep) {
    lua_pushinteger(L, pt->p[idx]->nups);
    return 1;
  }
  return 0;
}

/* for tag, mark in mfmiter do ... end. */
static int ju_mfmiter(lua_State *L)
{
  jit_Mfm *mfm = (jit_Mfm *)lua_touserdata(L, lua_upvalueindex(1));
  int m = *mfm--;
  switch (m) {
  case JIT_MFM_STOP: return 0;
  case JIT_MFM_COMBINE: lua_pushliteral(L, "COMBINE"); lua_pushnil(L); break;
  case JIT_MFM_DEAD: lua_pushliteral(L, "DEAD"); lua_pushnil(L); break;
  default:
    lua_pushinteger(L, m & JIT_MFM_MASK);
    lua_pushboolean(L, m & JIT_MFM_MARK);
    break;
  }
  lua_pushlightuserdata(L, (void *)mfm);
  lua_replace(L, lua_upvalueindex(1));
  return 2;
}

/* local addr, mcode, mfmiter = jit.util.mcode(func, block) */
static int ju_mcode(lua_State *L)
{
  Proto *pt = check_LCL(L)->l.p;
  if (pt->jit_szmcode == 0) {  /* Not compiled (yet): return nil, status. */
    lua_pushnil(L);
    lua_pushinteger(L, pt->jit_status);
    return 2;
  } else {
    jit_Mfm *mfm;
    jit_MCTrailer tr;
    int block = luaL_checkint(L, 2);
    tr.mcode = (char *)pt->jit_mcode;
    tr.sz = pt->jit_szmcode;
    while (--block > 0) {
      memcpy((void *)&tr, JIT_MCTRAILER(tr.mcode, tr.sz),
	     sizeof(jit_MCTrailer));
      if (tr.sz == 0) return 0;
    }
    mfm = JIT_MCMFM(tr.mcode, tr.sz);
    while (*mfm != JIT_MFM_STOP) mfm--;  /* Search for end of mcode. */
    lua_pushnumber(L, (lua_Number)(size_t)tr.mcode);
    lua_pushlstring(L, (const char *)tr.mcode, (char *)mfm-(char *)tr.mcode);
    lua_pushlightuserdata(L, (void *)JIT_MCMFM(tr.mcode, tr.sz));
    lua_pushvalue(L, 1);  /* Must hold onto function to avoid GC. */
    lua_pushcclosure(L, ju_mfmiter, 2);
    return 3;
  }
}

/* local addr [, mcode] = jit.util.jsubmcode([idx]) */
static int ju_jsubmcode(lua_State *L)
{
  jit_State *J = G(L)->jit_state;
  if (lua_isnoneornil(L, 1)) {
    lua_pushnumber(L, (lua_Number)(size_t)J->jsubmcode);
    lua_pushlstring(L, (const char *)J->jsubmcode, J->szjsubmcode);
    return 2;
  } else {
    int idx = luaL_checkint(L, 1);
    if (idx >= 0 && idx < J->numjsub) {
      lua_pushnumber(L, (lua_Number)(size_t)J->jsub[idx]);
      return 1;
    }
    return 0;
  }
}

/* FOR INTERNAL DEBUGGING USE ONLY: local addr = jit.util.stackptr() */
static int ju_stackptr(lua_State *L)
{
  jit_State *J = G(L)->jit_state;
  size_t addr = cast(size_t (*)(void), J->jsub[0])();  /* JSUB_STACKPTR == 0! */
  lua_pushnumber(L, (lua_Number)addr);
  return 1;
}

/* jit.util.* functions. */
static const luaL_Reg jitutillib[] = {
  {"stats",		ju_stats },
  {"bytecode",		ju_bytecode },
  {"const",		ju_const },
  {"upvalue",		ju_upvalue },
  {"closurenup",	ju_closurenup },
  {"mcode",		ju_mcode },
  {"jsubmcode",		ju_jsubmcode },
  {"stackptr",		ju_stackptr },
  { NULL, NULL }
};

/* Make hint name to hint number map. */
static void makehints(lua_State *L, const char *const *t, int tmax,
		      const char *name)
{
  int i;
  lua_createtable(L, 0, tmax);
  for (i = 1; i < tmax; i++) {
    lua_pushinteger(L, JIT_H2NUM(i));
    lua_setfield(L, -2, t[i-1]);
  }
  lua_setfield(L, -2, name);
}

/* CHECK: must match with ljit.h (grep "ORDER JIT_S"). */
static const char *const status_list[] = {
  "OK",
  "NONE",
  "OFF",
  "ENGINE_OFF",
  "DELAYED",
  "TOOLARGE",
  "COMPILER_ERROR",
  "DASM_ERROR"
};

/* Make bidirectional status name to status number map. */
static void makestatus(lua_State *L, const char *name)
{
  int i;
  lua_createtable(L, JIT_S_MAX-1, JIT_S_MAX+1);  /* Codes are not 1-based. */
  for (i = 0; i < JIT_S_MAX; i++) {
    lua_pushstring(L, status_list[i]);
    lua_pushinteger(L, i);
    lua_pushvalue(L, -2);
    lua_rawseti(L, -4, i);
    lua_rawset(L, -3);
  }
  lua_setfield(L, -2, name);
}

/* ------------------------------------------------------------------------ */

/*
** Open JIT library
*/
LUALIB_API int luaopen_jit(lua_State *L)
{
  /* Add the core JIT library. */
  luaL_register(L, LUA_JITLIBNAME, jitlib);
  lua_pushliteral(L, LUAJIT_VERSION);
  lua_setfield(L, -2, "version");
  setintfield("version_num", LUAJIT_VERSION_NUM);
  lua_pushstring(L, luaJIT_arch);
  lua_setfield(L, -2, "arch");
  makepipeline(L);

  /* Add the utility JIT library. */
  luaL_register(L, LUA_JITLIBNAME ".util", jitutillib);
  makestatus(L, "status");
  makehints(L, hints_H, JIT_H_MAX, "hints");
  makehints(L, hints_FH, JIT_FH_MAX, "fhints");
  lua_pop(L, 1);

  /* Everything ok, so turn the JIT engine on. Vroooom! */
  if (luaJIT_setmode(L, 0, LUAJIT_MODE_ENGINE|LUAJIT_MODE_ON) <= 0) {
    /* Ouch. Someone screwed up DynASM or the JSUBs. Probably me. */
    /* But if you get 999999999, look at jit_consistency_check(). */
    return luaL_error(L, "JIT engine init failed (%d)",
	G(L)->jit_state->dasmstatus);
  }

  return 1;
}