root/lib/lua/lcode.c

DEFINITIONS

1. isnumeral
2. luaK_nil
3. luaK_jump
4. luaK_ret
5. condjump
6. fixjump
7. luaK_getlabel
8. getjump
9. getjumpcontrol
10. need_value
11. patchtestreg
12. removevalues
13. patchlistaux
14. dischargejpc
15. luaK_patchlist
16. luaK_patchtohere
17. luaK_concat
18. luaK_checkstack
19. luaK_reserveregs
20. freereg
21. freeexp
22. addk
23. luaK_stringK
24. luaK_numberK
25. boolK
26. nilK
27. luaK_setreturns
28. luaK_setoneret
29. luaK_dischargevars
30. code_label
31. discharge2reg
32. discharge2anyreg
33. exp2reg
34. luaK_exp2nextreg
35. luaK_exp2anyreg
36. luaK_exp2val
37. luaK_exp2RK
38. luaK_storevar
39. luaK_self
40. invertjump
41. jumponcond
42. luaK_goiftrue
43. luaK_goiffalse
44. codenot
45. luaK_indexed
46. constfolding
47. codearith
48. codecomp
49. luaK_prefix
50. luaK_infix
51. luaK_posfix
52. luaK_fixline
53. luaK_code
54. luaK_codeABC
55. luaK_codeABx
56. luaK_setlist

   1 /*
   2 ** $Id: lcode.c,v 2.25.1.5 2011/01/31 14:53:16 roberto Exp $
   3 ** Code generator for Lua
   4 ** See Copyright Notice in lua.h
   5 */
   8 #include <stdlib.h>
  10 #define lcode_c
  11 #define LUA_CORE
  13 #include "lua.h"
  15 #include "lcode.h"
  16 #include "ldebug.h"
  17 #include "ldo.h"
  18 #include "lgc.h"
  19 #include "llex.h"
  20 #include "lmem.h"
  21 #include "lobject.h"
  22 #include "lopcodes.h"
  23 #include "lparser.h"
  24 #include "ltable.h"
  27 #define hasjumps(e)     ((e)->t != (e)->f)
  30 static int isnumeral(expdesc *e) {
  31   return (e->k == VKNUM && e->t == NO_JUMP && e->f == NO_JUMP);
  32 }
LUAI_FUNC void luaK_nil (FuncState *fs, int from, int n) {
Instruction *previous;
  37   if (fs->pc > fs->lasttarget) {  /* no jumps to current position? */
  38     if (fs->pc == 0) {  /* function start? */
  39       if (from >= fs->nactvar)
  40         return;  /* positions are already clean */
  41     }
  42     else {
previous = &fs->f->code[fs->pc-1];
  44       if (GET_OPCODE(*previous) == OP_LOADNIL) {
  45         int pfrom = GETARG_A(*previous);
  46         int pto = GETARG_B(*previous);
  47         if (pfrom <= from && from <= pto+1) {  /* can connect both? */
  48           if (from+n-1 > pto)
SETARG_B(*previous, from+n-1);
  50           return;
  51         }
  52       }
  53     }
  54   }
luaK_codeABC(fs, OP_LOADNIL, from, from+n-1, 0);  /* else no optimization */
  56 }
LUAI_FUNC int luaK_jump (FuncState *fs) {
  60   int jpc = fs->jpc;  /* save list of jumps to here */
  61   int j;
fs->jpc = NO_JUMP;
j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
luaK_concat(fs, &j, jpc);  /* keep them on hold */
  65   return j;
  66 }
LUAI_FUNC void luaK_ret (FuncState *fs, int first, int nret) {
luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);
  71 }
  74 static int condjump (FuncState *fs, OpCode op, int A, int B, int C) {
luaK_codeABC(fs, op, A, B, C);
  76   return luaK_jump(fs);
  77 }
  80 static void fixjump (FuncState *fs, int pc, int dest) {
Instruction *jmp = &fs->f->code[pc];
  82   int offset = dest-(pc+1);
lua_assert(dest != NO_JUMP);
  84   if (abs(offset) > MAXARG_sBx)
luaX_syntaxerror(fs->ls, "control structure too long");
SETARG_sBx(*jmp, offset);
  87 }
  90 /*
  91 ** returns current `pc' and marks it as a jump target (to avoid wrong
  92 ** optimizations with consecutive instructions not in the same basic block).
  93 */
LUAI_FUNC int luaK_getlabel (FuncState *fs) {
fs->lasttarget = fs->pc;
  96   return fs->pc;
  97 }
 100 static int getjump (FuncState *fs, int pc) {
 101   int offset = GETARG_sBx(fs->f->code[pc]);
 102   if (offset == NO_JUMP)  /* point to itself represents end of list */
 103     return NO_JUMP;  /* end of list */
 104   else
 105     return (pc+1)+offset;  /* turn offset into absolute position */
 106 }
 109 static Instruction *getjumpcontrol (FuncState *fs, int pc) {
Instruction *pi = &fs->f->code[pc];
 111   if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1))))
 112     return pi-1;
 113   else
 114     return pi;
 115 }
 118 /*
 119 ** check whether list has any jump that do not produce a value
 120 ** (or produce an inverted value)
 121 */
 122 static int need_value (FuncState *fs, int list) {
 123   for (; list != NO_JUMP; list = getjump(fs, list)) {
Instruction i = *getjumpcontrol(fs, list);
 125     if (GET_OPCODE(i) != OP_TESTSET) return 1;
 126   }
 127   return 0;  /* not found */
 128 }
 131 static int patchtestreg (FuncState *fs, int node, int reg) {
Instruction *i = getjumpcontrol(fs, node);
 133   if (GET_OPCODE(*i) != OP_TESTSET)
 134     return 0;  /* cannot patch other instructions */
 135   if (reg != NO_REG && reg != GETARG_B(*i))
SETARG_A(*i, reg);
 137   else  /* no register to put value or register already has the value */
 138     *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i));
 140   return 1;
 141 }
 144 static void removevalues (FuncState *fs, int list) {
 145   for (; list != NO_JUMP; list = getjump(fs, list))
patchtestreg(fs, list, NO_REG);
 147 }
 150 static void patchlistaux (FuncState *fs, int list, int vtarget, int reg,
 151                           int dtarget) {
 152   while (list != NO_JUMP) {
 153     int next = getjump(fs, list);
 154     if (patchtestreg(fs, list, reg))
fixjump(fs, list, vtarget);
 156     else
fixjump(fs, list, dtarget);  /* jump to default target */
list = next;
 159   }
 160 }
 163 static void dischargejpc (FuncState *fs) {
patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc);
fs->jpc = NO_JUMP;
 166 }
LUAI_FUNC void luaK_patchlist (FuncState *fs, int list, int target) {
 170   if (target == fs->pc)
luaK_patchtohere(fs, list);
 172   else {
lua_assert(target < fs->pc);
patchlistaux(fs, list, target, NO_REG, target);
 175   }
 176 }
LUAI_FUNC void luaK_patchtohere (FuncState *fs, int list) {
luaK_getlabel(fs);
luaK_concat(fs, &fs->jpc, list);
 182 }
LUAI_FUNC void luaK_concat (FuncState *fs, int *l1, int l2) {
 186   if (l2 == NO_JUMP) return;
 187   else if (*l1 == NO_JUMP)
 188     *l1 = l2;
 189   else {
 190     int list = *l1;
 191     int next;
 192     while ((next = getjump(fs, list)) != NO_JUMP)  /* find last element */
list = next;
fixjump(fs, list, l2);
 195   }
 196 }
LUAI_FUNC void luaK_checkstack (FuncState *fs, int n) {
 200   int newstack = fs->freereg + n;
 201   if (newstack > fs->f->maxstacksize) {
 202     if (newstack >= MAXSTACK)
luaX_syntaxerror(fs->ls, "function or expression too complex");
fs->f->maxstacksize = cast_byte(newstack);
 205   }
 206 }
LUAI_FUNC void luaK_reserveregs (FuncState *fs, int n) {
luaK_checkstack(fs, n);
fs->freereg += n;
 212 }
 215 static void freereg (FuncState *fs, int reg) {
 216   if (!ISK(reg) && reg >= fs->nactvar) {
fs->freereg--;
lua_assert(reg == fs->freereg);
 219   }
 220 }
 223 static void freeexp (FuncState *fs, expdesc *e) {
 224   if (e->k == VNONRELOC)
freereg(fs, e->u.s.info);
 226 }
 229 static int addk (FuncState *fs, TValue *k, TValue *v) {
lua_State *L = fs->L;
TValue *idx = luaH_set(L, fs->h, k);
Proto *f = fs->f;
 233   int oldsize = f->sizek;
 234   if (ttisnumber(idx)) {
lua_assert(luaO_rawequalObj(&fs->f->k[cast_int(nvalue(idx))], v));
 236     return cast_int(nvalue(idx));
 237   }
 238   else {  /* constant not found; create a new entry */
setnvalue(idx, cast_num(fs->nk));
luaM_growvector(L, f->k, fs->nk, f->sizek, TValue,
MAXARG_Bx, "constant table overflow");
 242     while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);
setobj(L, &f->k[fs->nk], v);
luaC_barrier(L, f, v);
 245     return fs->nk++;
 246   }
 247 }
LUAI_FUNC int luaK_stringK (FuncState *fs, TString *s) {
TValue o;
setsvalue(fs->L, &o, s);
 253   return addk(fs, &o, &o);
 254 }
LUAI_FUNC int luaK_numberK (FuncState *fs, lua_Number r) {
TValue o;
setnvalue(&o, r);
 260   return addk(fs, &o, &o);
 261 }
 264 static int boolK (FuncState *fs, int b) {
TValue o;
setbvalue(&o, b);
 267   return addk(fs, &o, &o);
 268 }
 271 static int nilK (FuncState *fs) {
TValue k, v;
setnilvalue(&v);
 274   /* cannot use nil as key; instead use table itself to represent nil */
sethvalue(fs->L, &k, fs->h);
 276   return addk(fs, &k, &v);
 277 }
LUAI_FUNC void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) {
 281   if (e->k == VCALL) {  /* expression is an open function call? */
SETARG_C(getcode(fs, e), nresults+1);
 283   }
 284   else if (e->k == VVARARG) {
SETARG_B(getcode(fs, e), nresults+1);
SETARG_A(getcode(fs, e), fs->freereg);
luaK_reserveregs(fs, 1);
 288   }
 289 }
LUAI_FUNC void luaK_setoneret (FuncState *fs, expdesc *e) {
 293   if (e->k == VCALL) {  /* expression is an open function call? */
e->k = VNONRELOC;
e->u.s.info = GETARG_A(getcode(fs, e));
 296   }
 297   else if (e->k == VVARARG) {
SETARG_B(getcode(fs, e), 2);
e->k = VRELOCABLE;  /* can relocate its simple result */
 300   }
 301 }
LUAI_FUNC void luaK_dischargevars (FuncState *fs, expdesc *e) {
 305   switch (e->k) {
 306     case VLOCAL: {
e->k = VNONRELOC;
 308       break;
 309     }
 310     case VUPVAL: {
e->u.s.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.s.info, 0);
e->k = VRELOCABLE;
 313       break;
 314     }
 315     case VGLOBAL: {
e->u.s.info = luaK_codeABx(fs, OP_GETGLOBAL, 0, e->u.s.info);
e->k = VRELOCABLE;
 318       break;
 319     }
 320     case VINDEXED: {
freereg(fs, e->u.s.aux);
freereg(fs, e->u.s.info);
e->u.s.info = luaK_codeABC(fs, OP_GETTABLE, 0, e->u.s.info, e->u.s.aux);
e->k = VRELOCABLE;
 325       break;
 326     }
 327     case VVARARG:
 328     case VCALL: {
luaK_setoneret(fs, e);
 330       break;
 331     }
 332     default: break;  /* there is one value available (somewhere) */
 333   }
 334 }
 337 static int code_label (FuncState *fs, int A, int b, int jump) {
luaK_getlabel(fs);  /* those instructions may be jump targets */
 339   return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
 340 }
 343 static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
luaK_dischargevars(fs, e);
 345   switch (e->k) {
 346     case VNIL: {
luaK_nil(fs, reg, 1);
 348       break;
 349     }
 350     case VFALSE:  case VTRUE: {
luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0);
 352       break;
 353     }
 354     case VK: {
luaK_codeABx(fs, OP_LOADK, reg, e->u.s.info);
 356       break;
 357     }
 358     case VKNUM: {
luaK_codeABx(fs, OP_LOADK, reg, luaK_numberK(fs, e->u.nval));
 360       break;
 361     }
 362     case VRELOCABLE: {
Instruction *pc = &getcode(fs, e);
SETARG_A(*pc, reg);
 365       break;
 366     }
 367     case VNONRELOC: {
 368       if (reg != e->u.s.info)
luaK_codeABC(fs, OP_MOVE, reg, e->u.s.info, 0);
 370       break;
 371     }
 372     default: {
lua_assert(e->k == VVOID || e->k == VJMP);
 374       return;  /* nothing to do... */
 375     }
 376   }
e->u.s.info = reg;
e->k = VNONRELOC;
 379 }
 382 static void discharge2anyreg (FuncState *fs, expdesc *e) {
 383   if (e->k != VNONRELOC) {
luaK_reserveregs(fs, 1);
discharge2reg(fs, e, fs->freereg-1);
 386   }
 387 }
 390 static void exp2reg (FuncState *fs, expdesc *e, int reg) {
discharge2reg(fs, e, reg);
 392   if (e->k == VJMP)
luaK_concat(fs, &e->t, e->u.s.info);  /* put this jump in `t' list */
 394   if (hasjumps(e)) {
 395     int final;  /* position after whole expression */
 396     int p_f = NO_JUMP;  /* position of an eventual LOAD false */
 397     int p_t = NO_JUMP;  /* position of an eventual LOAD true */
 398     if (need_value(fs, e->t) || need_value(fs, e->f)) {
 399       int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);
p_f = code_label(fs, reg, 0, 1);
p_t = code_label(fs, reg, 1, 0);
luaK_patchtohere(fs, fj);
 403     }
final = luaK_getlabel(fs);
patchlistaux(fs, e->f, final, reg, p_f);
patchlistaux(fs, e->t, final, reg, p_t);
 407   }
e->f = e->t = NO_JUMP;
e->u.s.info = reg;
e->k = VNONRELOC;
 411 }
LUAI_FUNC void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
luaK_dischargevars(fs, e);
freeexp(fs, e);
luaK_reserveregs(fs, 1);
exp2reg(fs, e, fs->freereg - 1);
 419 }
LUAI_FUNC int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
luaK_dischargevars(fs, e);
 424   if (e->k == VNONRELOC) {
 425     if (!hasjumps(e)) return e->u.s.info;  /* exp is already in a register */
 426     if (e->u.s.info >= fs->nactvar) {  /* reg. is not a local? */
exp2reg(fs, e, e->u.s.info);  /* put value on it */
 428       return e->u.s.info;
 429     }
 430   }
luaK_exp2nextreg(fs, e);  /* default */
 432   return e->u.s.info;
 433 }
LUAI_FUNC void luaK_exp2val (FuncState *fs, expdesc *e) {
 437   if (hasjumps(e))
luaK_exp2anyreg(fs, e);
 439   else
luaK_dischargevars(fs, e);
 441 }
LUAI_FUNC int luaK_exp2RK (FuncState *fs, expdesc *e) {
luaK_exp2val(fs, e);
 446   switch (e->k) {
 447     case VKNUM:
 448     case VTRUE:
 449     case VFALSE:
 450     case VNIL: {
 451       if (fs->nk <= MAXINDEXRK) {  /* constant fit in RK operand? */
e->u.s.info = (e->k == VNIL)  ? nilK(fs) :
 453                       (e->k == VKNUM) ? luaK_numberK(fs, e->u.nval) :
boolK(fs, (e->k == VTRUE));
e->k = VK;
 456         return RKASK(e->u.s.info);
 457       }
 458       else break;
 459     }
 460     case VK: {
 461       if (e->u.s.info <= MAXINDEXRK)  /* constant fit in argC? */
 462         return RKASK(e->u.s.info);
 463       else break;
 464     }
 465     default: break;
 466   }
 467   /* not a constant in the right range: put it in a register */
 468   return luaK_exp2anyreg(fs, e);
 469 }
LUAI_FUNC void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
 473   switch (var->k) {
 474     case VLOCAL: {
freeexp(fs, ex);
exp2reg(fs, ex, var->u.s.info);
 477       return;
 478     }
 479     case VUPVAL: {
 480       int e = luaK_exp2anyreg(fs, ex);
luaK_codeABC(fs, OP_SETUPVAL, e, var->u.s.info, 0);
 482       break;
 483     }
 484     case VGLOBAL: {
 485       int e = luaK_exp2anyreg(fs, ex);
luaK_codeABx(fs, OP_SETGLOBAL, e, var->u.s.info);
 487       break;
 488     }
 489     case VINDEXED: {
 490       int e = luaK_exp2RK(fs, ex);
luaK_codeABC(fs, OP_SETTABLE, var->u.s.info, var->u.s.aux, e);
 492       break;
 493     }
 494     default: {
lua_assert(0);  /* invalid var kind to store */
 496       break;
 497     }
 498   }
freeexp(fs, ex);
 500 }
LUAI_FUNC void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
 504   int func;
luaK_exp2anyreg(fs, e);
freeexp(fs, e);
func = fs->freereg;
luaK_reserveregs(fs, 2);
luaK_codeABC(fs, OP_SELF, func, e->u.s.info, luaK_exp2RK(fs, key));
freeexp(fs, key);
e->u.s.info = func;
e->k = VNONRELOC;
 513 }
 516 static void invertjump (FuncState *fs, expdesc *e) {
Instruction *pc = getjumpcontrol(fs, e->u.s.info);
lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET &&
GET_OPCODE(*pc) != OP_TEST);
SETARG_A(*pc, !(GETARG_A(*pc)));
 521 }
 524 static int jumponcond (FuncState *fs, expdesc *e, int cond) {
 525   if (e->k == VRELOCABLE) {
Instruction ie = getcode(fs, e);
 527     if (GET_OPCODE(ie) == OP_NOT) {
fs->pc--;  /* remove previous OP_NOT */
 529       return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond);
 530     }
 531     /* else go through */
 532   }
discharge2anyreg(fs, e);
freeexp(fs, e);
 535   return condjump(fs, OP_TESTSET, NO_REG, e->u.s.info, cond);
 536 }
LUAI_FUNC void luaK_goiftrue (FuncState *fs, expdesc *e) {
 540   int pc;  /* pc of last jump */
luaK_dischargevars(fs, e);
 542   switch (e->k) {
 543     case VK: case VKNUM: case VTRUE: {
pc = NO_JUMP;  /* always true; do nothing */
 545       break;
 546     }
 547     case VJMP: {
invertjump(fs, e);
pc = e->u.s.info;
 550       break;
 551     }
 552     default: {
pc = jumponcond(fs, e, 0);
 554       break;
 555     }
 556   }
luaK_concat(fs, &e->f, pc);  /* insert last jump in `f' list */
luaK_patchtohere(fs, e->t);
e->t = NO_JUMP;
 560 }
 563 static void luaK_goiffalse (FuncState *fs, expdesc *e) {
 564   int pc;  /* pc of last jump */
luaK_dischargevars(fs, e);
 566   switch (e->k) {
 567     case VNIL: case VFALSE: {
pc = NO_JUMP;  /* always false; do nothing */
 569       break;
 570     }
 571     case VJMP: {
pc = e->u.s.info;
 573       break;
 574     }
 575     default: {
pc = jumponcond(fs, e, 1);
 577       break;
 578     }
 579   }
luaK_concat(fs, &e->t, pc);  /* insert last jump in `t' list */
luaK_patchtohere(fs, e->f);
e->f = NO_JUMP;
 583 }
 586 static void codenot (FuncState *fs, expdesc *e) {
luaK_dischargevars(fs, e);
 588   switch (e->k) {
 589     case VNIL: case VFALSE: {
e->k = VTRUE;
 591       break;
 592     }
 593     case VK: case VKNUM: case VTRUE: {
e->k = VFALSE;
 595       break;
 596     }
 597     case VJMP: {
invertjump(fs, e);
 599       break;
 600     }
 601     case VRELOCABLE:
 602     case VNONRELOC: {
discharge2anyreg(fs, e);
freeexp(fs, e);
e->u.s.info = luaK_codeABC(fs, OP_NOT, 0, e->u.s.info, 0);
e->k = VRELOCABLE;
 607       break;
 608     }
 609     default: {
lua_assert(0);  /* cannot happen */
 611       break;
 612     }
 613   }
 614   /* interchange true and false lists */
 615   { int temp = e->f; e->f = e->t; e->t = temp; }
removevalues(fs, e->f);
removevalues(fs, e->t);
 618 }
LUAI_FUNC void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
t->u.s.aux = luaK_exp2RK(fs, k);
t->k = VINDEXED;
 624 }
 627 static int constfolding (OpCode op, expdesc *e1, expdesc *e2) {
lua_Number v1, v2, r;
 629   if (!isnumeral(e1) || !isnumeral(e2)) return 0;
v1 = e1->u.nval;
v2 = e2->u.nval;
 632   switch (op) {
 633     case OP_ADD: r = luai_numadd(v1, v2); break;
 634     case OP_SUB: r = luai_numsub(v1, v2); break;
 635     case OP_MUL: r = luai_nummul(v1, v2); break;
 636     case OP_DIV:
 637       if (v2 == 0) return 0;  /* do not attempt to divide by 0 */
r = luai_numdiv(v1, v2); break;
 639     case OP_MOD:
 640       if (v2 == 0) return 0;  /* do not attempt to divide by 0 */
r = luai_nummod(v1, v2); break;
 642     case OP_POW: r = luai_numpow(v1, v2); break;
 643     case OP_UNM: r = luai_numunm(v1); break;
 644     case OP_LEN: return 0;  /* no constant folding for 'len' */
 645     default: lua_assert(0); r = 0; break;
 646   }
 647   if (luai_numisnan(r)) return 0;  /* do not attempt to produce NaN */
e1->u.nval = r;
 649   return 1;
 650 }
 653 static void codearith (FuncState *fs, OpCode op, expdesc *e1, expdesc *e2) {
 654   if (constfolding(op, e1, e2))
 655     return;
 656   else {
 657     int o2 = (op != OP_UNM && op != OP_LEN) ? luaK_exp2RK(fs, e2) : 0;
 658     int o1 = luaK_exp2RK(fs, e1);
 659     if (o1 > o2) {
freeexp(fs, e1);
freeexp(fs, e2);
 662     }
 663     else {
freeexp(fs, e2);
freeexp(fs, e1);
 666     }
e1->u.s.info = luaK_codeABC(fs, op, 0, o1, o2);
e1->k = VRELOCABLE;
 669   }
 670 }
 673 static void codecomp (FuncState *fs, OpCode op, int cond, expdesc *e1,
expdesc *e2) {
 675   int o1 = luaK_exp2RK(fs, e1);
 676   int o2 = luaK_exp2RK(fs, e2);
freeexp(fs, e2);
freeexp(fs, e1);
 679   if (cond == 0 && op != OP_EQ) {
 680     int temp;  /* exchange args to replace by `<' or `<=' */
temp = o1; o1 = o2; o2 = temp;  /* o1 <==> o2 */
cond = 1;
 683   }
e1->u.s.info = condjump(fs, op, cond, o1, o2);
e1->k = VJMP;
 686 }
LUAI_FUNC void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e) {
expdesc e2;
e2.t = e2.f = NO_JUMP; e2.k = VKNUM; e2.u.nval = 0;
 692   switch (op) {
 693     case OPR_MINUS: {
 694       if (!isnumeral(e))
luaK_exp2anyreg(fs, e);  /* cannot operate on non-numeric constants */
codearith(fs, OP_UNM, e, &e2);
 697       break;
 698     }
 699     case OPR_NOT: codenot(fs, e); break;
 700     case OPR_LEN: {
luaK_exp2anyreg(fs, e);  /* cannot operate on constants */
codearith(fs, OP_LEN, e, &e2);
 703       break;
 704     }
 705     default: lua_assert(0);
 706   }
 707 }
LUAI_FUNC void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
 711   switch (op) {
 712     case OPR_AND: {
luaK_goiftrue(fs, v);
 714       break;
 715     }
 716     case OPR_OR: {
luaK_goiffalse(fs, v);
 718       break;
 719     }
 720     case OPR_CONCAT: {
luaK_exp2nextreg(fs, v);  /* operand must be on the `stack' */
 722       break;
 723     }
 724     case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:
 725     case OPR_MOD: case OPR_POW: {
 726       if (!isnumeral(v)) luaK_exp2RK(fs, v);
 727       break;
 728     }
 729     default: {
luaK_exp2RK(fs, v);
 731       break;
 732     }
 733   }
 734 }
LUAI_FUNC void luaK_posfix (FuncState *fs, BinOpr op, expdesc *e1, expdesc *e2) {
 738   switch (op) {
 739     case OPR_AND: {
lua_assert(e1->t == NO_JUMP);  /* list must be closed */
luaK_dischargevars(fs, e2);
luaK_concat(fs, &e2->f, e1->f);
 743       *e1 = *e2;
 744       break;
 745     }
 746     case OPR_OR: {
lua_assert(e1->f == NO_JUMP);  /* list must be closed */
luaK_dischargevars(fs, e2);
luaK_concat(fs, &e2->t, e1->t);
 750       *e1 = *e2;
 751       break;
 752     }
 753     case OPR_CONCAT: {
luaK_exp2val(fs, e2);
 755       if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) {
lua_assert(e1->u.s.info == GETARG_B(getcode(fs, e2))-1);
freeexp(fs, e1);
SETARG_B(getcode(fs, e2), e1->u.s.info);
e1->k = VRELOCABLE; e1->u.s.info = e2->u.s.info;
 760       }
 761       else {
luaK_exp2nextreg(fs, e2);  /* operand must be on the 'stack' */
codearith(fs, OP_CONCAT, e1, e2);
 764       }
 765       break;
 766     }
 767     case OPR_ADD: codearith(fs, OP_ADD, e1, e2); break;
 768     case OPR_SUB: codearith(fs, OP_SUB, e1, e2); break;
 769     case OPR_MUL: codearith(fs, OP_MUL, e1, e2); break;
 770     case OPR_DIV: codearith(fs, OP_DIV, e1, e2); break;
 771     case OPR_MOD: codearith(fs, OP_MOD, e1, e2); break;
 772     case OPR_POW: codearith(fs, OP_POW, e1, e2); break;
 773     case OPR_EQ: codecomp(fs, OP_EQ, 1, e1, e2); break;
 774     case OPR_NE: codecomp(fs, OP_EQ, 0, e1, e2); break;
 775     case OPR_LT: codecomp(fs, OP_LT, 1, e1, e2); break;
 776     case OPR_LE: codecomp(fs, OP_LE, 1, e1, e2); break;
 777     case OPR_GT: codecomp(fs, OP_LT, 0, e1, e2); break;
 778     case OPR_GE: codecomp(fs, OP_LE, 0, e1, e2); break;
 779     default: lua_assert(0);
 780   }
 781 }
LUAI_FUNC void luaK_fixline (FuncState *fs, int line) {
fs->f->lineinfo[fs->pc - 1] = line;
 786 }
 789 static int luaK_code (FuncState *fs, Instruction i, int line) {
Proto *f = fs->f;
dischargejpc(fs);  /* `pc' will change */
 792   /* put new instruction in code array */
luaM_growvector(fs->L, f->code, fs->pc, f->sizecode, Instruction,
MAX_INT, "code size overflow");
f->code[fs->pc] = i;
 796   /* save corresponding line information */
luaM_growvector(fs->L, f->lineinfo, fs->pc, f->sizelineinfo, int,
MAX_INT, "code size overflow");
f->lineinfo[fs->pc] = line;
 800   return fs->pc++;
 801 }
LUAI_FUNC int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
lua_assert(getOpMode(o) == iABC);
lua_assert(getBMode(o) != OpArgN || b == 0);
lua_assert(getCMode(o) != OpArgN || c == 0);
 808   return luaK_code(fs, CREATE_ABC(o, a, b, c), fs->ls->lastline);
 809 }
LUAI_FUNC int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);
lua_assert(getCMode(o) == OpArgN);
 815   return luaK_code(fs, CREATE_ABx(o, a, bc), fs->ls->lastline);
 816 }
LUAI_FUNC void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) {
 820   int c =  (nelems - 1)/LFIELDS_PER_FLUSH + 1;
 821   int b = (tostore == LUA_MULTRET) ? 0 : tostore;
lua_assert(tostore != 0);
 823   if (c <= MAXARG_C)
luaK_codeABC(fs, OP_SETLIST, base, b, c);
 825   else {
luaK_codeABC(fs, OP_SETLIST, base, b, 0);
luaK_code(fs, cast(Instruction, c), fs->ls->lastline);
 828   }
fs->freereg = base + 1;  /* free registers with list values */
 830 }