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ffi/target/release/build/mlua-sys-6a99a2ae50f12319/out/luajit-build/build/src/lj_parse.c  view on Meta::CPAN

LJ_STATIC_ASSERT((int)BC_DIVVV-(int)BC_ADDVV == (int)OPR_DIV-(int)OPR_ADD);
LJ_STATIC_ASSERT((int)BC_MODVV-(int)BC_ADDVV == (int)OPR_MOD-(int)OPR_ADD);

#ifdef LUA_USE_ASSERT
#define lj_assertFS(c, ...)	(lj_assertG_(G(fs->L), (c), __VA_ARGS__))
#else
#define lj_assertFS(c, ...)	((void)fs)
#endif

/* -- Error handling ------------------------------------------------------ */

LJ_NORET LJ_NOINLINE static void err_syntax(LexState *ls, ErrMsg em)
{
  lj_lex_error(ls, ls->tok, em);
}

LJ_NORET LJ_NOINLINE static void err_token(LexState *ls, LexToken tok)
{
  lj_lex_error(ls, ls->tok, LJ_ERR_XTOKEN, lj_lex_token2str(ls, tok));
}

LJ_NORET static void err_limit(FuncState *fs, uint32_t limit, const char *what)
{
  if (fs->linedefined == 0)
    lj_lex_error(fs->ls, 0, LJ_ERR_XLIMM, limit, what);
  else
    lj_lex_error(fs->ls, 0, LJ_ERR_XLIMF, fs->linedefined, limit, what);
}

#define checklimit(fs, v, l, m)		if ((v) >= (l)) err_limit(fs, l, m)
#define checklimitgt(fs, v, l, m)	if ((v) > (l)) err_limit(fs, l, m)
#define checkcond(ls, c, em)		{ if (!(c)) err_syntax(ls, em); }

/* -- Management of constants --------------------------------------------- */

/* Return bytecode encoding for primitive constant. */
#define const_pri(e)		check_exp((e)->k <= VKTRUE, (e)->k)

#define tvhaskslot(o)	((o)->u32.hi == 0)
#define tvkslot(o)	((o)->u32.lo)

/* Add a number constant. */
static BCReg const_num(FuncState *fs, ExpDesc *e)
{
  lua_State *L = fs->L;
  TValue *o;
  lj_assertFS(expr_isnumk(e), "bad usage");
  o = lj_tab_set(L, fs->kt, &e->u.nval);
  if (tvhaskslot(o))
    return tvkslot(o);
  o->u64 = fs->nkn;
  return fs->nkn++;
}

/* Add a GC object constant. */
static BCReg const_gc(FuncState *fs, GCobj *gc, uint32_t itype)
{
  lua_State *L = fs->L;
  TValue key, *o;
  setgcV(L, &key, gc, itype);
  /* NOBARRIER: the key is new or kept alive. */
  o = lj_tab_set(L, fs->kt, &key);
  if (tvhaskslot(o))
    return tvkslot(o);
  o->u64 = fs->nkgc;
  return fs->nkgc++;
}

/* Add a string constant. */
static BCReg const_str(FuncState *fs, ExpDesc *e)
{
  lj_assertFS(expr_isstrk(e) || e->k == VGLOBAL, "bad usage");
  return const_gc(fs, obj2gco(e->u.sval), LJ_TSTR);
}

/* Anchor string constant to avoid GC. */
GCstr *lj_parse_keepstr(LexState *ls, const char *str, size_t len)
{
  /* NOBARRIER: the key is new or kept alive. */
  lua_State *L = ls->L;
  GCstr *s = lj_str_new(L, str, len);
  TValue *tv = lj_tab_setstr(L, ls->fs->kt, s);
  if (tvisnil(tv)) setboolV(tv, 1);
  lj_gc_check(L);
  return s;
}

#if LJ_HASFFI
/* Anchor cdata to avoid GC. */
void lj_parse_keepcdata(LexState *ls, TValue *tv, GCcdata *cd)
{
  /* NOBARRIER: the key is new or kept alive. */
  lua_State *L = ls->L;
  setcdataV(L, tv, cd);
  setboolV(lj_tab_set(L, ls->fs->kt, tv), 1);
}
#endif

/* -- Jump list handling -------------------------------------------------- */

/* Get next element in jump list. */
static BCPos jmp_next(FuncState *fs, BCPos pc)
{
  ptrdiff_t delta = bc_j(fs->bcbase[pc].ins);
  if ((BCPos)delta == NO_JMP)
    return NO_JMP;
  else
    return (BCPos)(((ptrdiff_t)pc+1)+delta);
}

/* Check if any of the instructions on the jump list produce no value. */
static int jmp_novalue(FuncState *fs, BCPos list)
{
  for (; list != NO_JMP; list = jmp_next(fs, list)) {
    BCIns p = fs->bcbase[list >= 1 ? list-1 : list].ins;
    if (!(bc_op(p) == BC_ISTC || bc_op(p) == BC_ISFC || bc_a(p) == NO_REG))
      return 1;
  }
  return 0;
}

/* Patch register of test instructions. */
static int jmp_patchtestreg(FuncState *fs, BCPos pc, BCReg reg)
{
  BCInsLine *ilp = &fs->bcbase[pc >= 1 ? pc-1 : pc];
  BCOp op = bc_op(ilp->ins);
  if (op == BC_ISTC || op == BC_ISFC) {
    if (reg != NO_REG && reg != bc_d(ilp->ins)) {
      setbc_a(&ilp->ins, reg);
    } else {  /* Nothing to store or already in the right register. */
      setbc_op(&ilp->ins, op+(BC_IST-BC_ISTC));
      setbc_a(&ilp->ins, 0);
    }
  } else if (bc_a(ilp->ins) == NO_REG) {
    if (reg == NO_REG) {
      ilp->ins = BCINS_AJ(BC_JMP, bc_a(fs->bcbase[pc].ins), 0);
    } else {
      setbc_a(&ilp->ins, reg);
      if (reg >= bc_a(ilp[1].ins))
	setbc_a(&ilp[1].ins, reg+1);
    }
  } else {
    return 0;  /* Cannot patch other instructions. */
  }
  return 1;
}

/* Drop values for all instructions on jump list. */
static void jmp_dropval(FuncState *fs, BCPos list)
{
  for (; list != NO_JMP; list = jmp_next(fs, list))
    jmp_patchtestreg(fs, list, NO_REG);