2 ** Lua parser (source code -> bytecode).
3 ** Copyright (C) 2005-2014 Mike Pall. See Copyright Notice in luajit.h
5 ** Major portions taken verbatim or adapted from the Lua interpreter.
6 ** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
25 #include "lj_strfmt.h"
29 #include "lj_vmevent.h"
31 /* -- Parser structures and definitions ----------------------------------- */
33 /* Expression kinds. */
35 /* Constant expressions must be first and in this order: */
39 VKSTR
, /* sval = string value */
40 VKNUM
, /* nval = number value */
42 VKCDATA
, /* nval = cdata value, not treated as a constant expression */
43 /* Non-constant expressions follow: */
44 VLOCAL
, /* info = local register, aux = vstack index */
45 VUPVAL
, /* info = upvalue index, aux = vstack index */
46 VGLOBAL
, /* sval = string value */
47 VINDEXED
, /* info = table register, aux = index reg/byte/string const */
48 VJMP
, /* info = instruction PC */
49 VRELOCABLE
, /* info = instruction PC */
50 VNONRELOC
, /* info = result register */
51 VCALL
, /* info = instruction PC, aux = base */
55 /* Expression descriptor. */
56 typedef struct ExpDesc
{
59 uint32_t info
; /* Primary info. */
60 uint32_t aux
; /* Secondary info. */
62 TValue nval
; /* Number value. */
63 GCstr
*sval
; /* String value. */
66 BCPos t
; /* True condition jump list. */
67 BCPos f
; /* False condition jump list. */
70 /* Macros for expressions. */
71 #define expr_hasjump(e) ((e)->t != (e)->f)
73 #define expr_isk(e) ((e)->k <= VKLAST)
74 #define expr_isk_nojump(e) (expr_isk(e) && !expr_hasjump(e))
75 #define expr_isnumk(e) ((e)->k == VKNUM)
76 #define expr_isnumk_nojump(e) (expr_isnumk(e) && !expr_hasjump(e))
77 #define expr_isstrk(e) ((e)->k == VKSTR)
79 #define expr_numtv(e) check_exp(expr_isnumk((e)), &(e)->u.nval)
80 #define expr_numberV(e) numberVnum(expr_numtv((e)))
82 /* Initialize expression. */
83 static LJ_AINLINE
void expr_init(ExpDesc
*e
, ExpKind k
, uint32_t info
)
90 /* Check number constant for +-0. */
91 static int expr_numiszero(ExpDesc
*e
)
93 TValue
*o
= expr_numtv(e
);
94 return tvisint(o
) ? (intV(o
) == 0) : tviszero(o
);
97 /* Per-function linked list of scope blocks. */
98 typedef struct FuncScope
{
99 struct FuncScope
*prev
; /* Link to outer scope. */
100 MSize vstart
; /* Start of block-local variables. */
101 uint8_t nactvar
; /* Number of active vars outside the scope. */
102 uint8_t flags
; /* Scope flags. */
105 #define FSCOPE_LOOP 0x01 /* Scope is a (breakable) loop. */
106 #define FSCOPE_BREAK 0x02 /* Break used in scope. */
107 #define FSCOPE_GOLA 0x04 /* Goto or label used in scope. */
108 #define FSCOPE_UPVAL 0x08 /* Upvalue in scope. */
109 #define FSCOPE_NOCLOSE 0x10 /* Do not close upvalues. */
111 #define NAME_BREAK ((GCstr *)(uintptr_t)1)
113 /* Index into variable stack. */
114 typedef uint16_t VarIndex
;
115 #define LJ_MAX_VSTACK (65536 - LJ_MAX_UPVAL)
117 /* Variable/goto/label info. */
118 #define VSTACK_VAR_RW 0x01 /* R/W variable. */
119 #define VSTACK_GOTO 0x02 /* Pending goto. */
120 #define VSTACK_LABEL 0x04 /* Label. */
122 /* Per-function state. */
123 typedef struct FuncState
{
124 GCtab
*kt
; /* Hash table for constants. */
125 LexState
*ls
; /* Lexer state. */
126 lua_State
*L
; /* Lua state. */
127 FuncScope
*bl
; /* Current scope. */
128 struct FuncState
*prev
; /* Enclosing function. */
129 BCPos pc
; /* Next bytecode position. */
130 BCPos lasttarget
; /* Bytecode position of last jump target. */
131 BCPos jpc
; /* Pending jump list to next bytecode. */
132 BCReg freereg
; /* First free register. */
133 BCReg nactvar
; /* Number of active local variables. */
134 BCReg nkn
, nkgc
; /* Number of lua_Number/GCobj constants */
135 BCLine linedefined
; /* First line of the function definition. */
136 BCInsLine
*bcbase
; /* Base of bytecode stack. */
137 BCPos bclim
; /* Limit of bytecode stack. */
138 MSize vbase
; /* Base of variable stack for this function. */
139 uint8_t flags
; /* Prototype flags. */
140 uint8_t numparams
; /* Number of parameters. */
141 uint8_t framesize
; /* Fixed frame size. */
142 uint8_t nuv
; /* Number of upvalues */
143 VarIndex varmap
[LJ_MAX_LOCVAR
]; /* Map from register to variable idx. */
144 VarIndex uvmap
[LJ_MAX_UPVAL
]; /* Map from upvalue to variable idx. */
145 VarIndex uvtmp
[LJ_MAX_UPVAL
]; /* Temporary upvalue map. */
148 /* Binary and unary operators. ORDER OPR */
149 typedef enum BinOpr
{
150 OPR_ADD
, OPR_SUB
, OPR_MUL
, OPR_DIV
, OPR_MOD
, OPR_POW
, /* ORDER ARITH */
153 OPR_LT
, OPR_GE
, OPR_LE
, OPR_GT
,
158 LJ_STATIC_ASSERT((int)BC_ISGE
-(int)BC_ISLT
== (int)OPR_GE
-(int)OPR_LT
);
159 LJ_STATIC_ASSERT((int)BC_ISLE
-(int)BC_ISLT
== (int)OPR_LE
-(int)OPR_LT
);
160 LJ_STATIC_ASSERT((int)BC_ISGT
-(int)BC_ISLT
== (int)OPR_GT
-(int)OPR_LT
);
161 LJ_STATIC_ASSERT((int)BC_SUBVV
-(int)BC_ADDVV
== (int)OPR_SUB
-(int)OPR_ADD
);
162 LJ_STATIC_ASSERT((int)BC_MULVV
-(int)BC_ADDVV
== (int)OPR_MUL
-(int)OPR_ADD
);
163 LJ_STATIC_ASSERT((int)BC_DIVVV
-(int)BC_ADDVV
== (int)OPR_DIV
-(int)OPR_ADD
);
164 LJ_STATIC_ASSERT((int)BC_MODVV
-(int)BC_ADDVV
== (int)OPR_MOD
-(int)OPR_ADD
);
166 /* -- Error handling ------------------------------------------------------ */
168 LJ_NORET LJ_NOINLINE
static void err_syntax(LexState
*ls
, ErrMsg em
)
170 lj_lex_error(ls
, ls
->tok
, em
);
173 LJ_NORET LJ_NOINLINE
static void err_token(LexState
*ls
, LexToken tok
)
175 lj_lex_error(ls
, ls
->tok
, LJ_ERR_XTOKEN
, lj_lex_token2str(ls
, tok
));
178 LJ_NORET
static void err_limit(FuncState
*fs
, uint32_t limit
, const char *what
)
180 if (fs
->linedefined
== 0)
181 lj_lex_error(fs
->ls
, 0, LJ_ERR_XLIMM
, limit
, what
);
183 lj_lex_error(fs
->ls
, 0, LJ_ERR_XLIMF
, fs
->linedefined
, limit
, what
);
186 #define checklimit(fs, v, l, m) if ((v) >= (l)) err_limit(fs, l, m)
187 #define checklimitgt(fs, v, l, m) if ((v) > (l)) err_limit(fs, l, m)
188 #define checkcond(ls, c, em) { if (!(c)) err_syntax(ls, em); }
190 /* -- Management of constants --------------------------------------------- */
192 /* Return bytecode encoding for primitive constant. */
193 #define const_pri(e) check_exp((e)->k <= VKTRUE, (e)->k)
195 #define tvhaskslot(o) ((o)->u32.hi == 0)
196 #define tvkslot(o) ((o)->u32.lo)
198 /* Add a number constant. */
199 static BCReg
const_num(FuncState
*fs
, ExpDesc
*e
)
201 lua_State
*L
= fs
->L
;
203 lua_assert(expr_isnumk(e
));
204 o
= lj_tab_set(L
, fs
->kt
, &e
->u
.nval
);
211 /* Add a GC object constant. */
212 static BCReg
const_gc(FuncState
*fs
, GCobj
*gc
, uint32_t itype
)
214 lua_State
*L
= fs
->L
;
216 setgcV(L
, &key
, gc
, itype
);
217 /* NOBARRIER: the key is new or kept alive. */
218 o
= lj_tab_set(L
, fs
->kt
, &key
);
225 /* Add a string constant. */
226 static BCReg
const_str(FuncState
*fs
, ExpDesc
*e
)
228 lua_assert(expr_isstrk(e
) || e
->k
== VGLOBAL
);
229 return const_gc(fs
, obj2gco(e
->u
.sval
), LJ_TSTR
);
232 /* Anchor string constant to avoid GC. */
233 GCstr
*lj_parse_keepstr(LexState
*ls
, const char *str
, size_t len
)
235 /* NOBARRIER: the key is new or kept alive. */
236 lua_State
*L
= ls
->L
;
237 GCstr
*s
= lj_str_new(L
, str
, len
);
238 TValue
*tv
= lj_tab_setstr(L
, ls
->fs
->kt
, s
);
239 if (tvisnil(tv
)) setboolV(tv
, 1);
245 /* Anchor cdata to avoid GC. */
246 void lj_parse_keepcdata(LexState
*ls
, TValue
*tv
, GCcdata
*cd
)
248 /* NOBARRIER: the key is new or kept alive. */
249 lua_State
*L
= ls
->L
;
250 setcdataV(L
, tv
, cd
);
251 setboolV(lj_tab_set(L
, ls
->fs
->kt
, tv
), 1);
255 /* -- Jump list handling -------------------------------------------------- */
257 /* Get next element in jump list. */
258 static BCPos
jmp_next(FuncState
*fs
, BCPos pc
)
260 ptrdiff_t delta
= bc_j(fs
->bcbase
[pc
].ins
);
261 if ((BCPos
)delta
== NO_JMP
)
264 return (BCPos
)(((ptrdiff_t)pc
+1)+delta
);
267 /* Check if any of the instructions on the jump list produce no value. */
268 static int jmp_novalue(FuncState
*fs
, BCPos list
)
270 for (; list
!= NO_JMP
; list
= jmp_next(fs
, list
)) {
271 BCIns p
= fs
->bcbase
[list
>= 1 ? list
-1 : list
].ins
;
272 if (!(bc_op(p
) == BC_ISTC
|| bc_op(p
) == BC_ISFC
|| bc_a(p
) == NO_REG
))
278 /* Patch register of test instructions. */
279 static int jmp_patchtestreg(FuncState
*fs
, BCPos pc
, BCReg reg
)
281 BCInsLine
*ilp
= &fs
->bcbase
[pc
>= 1 ? pc
-1 : pc
];
282 BCOp op
= bc_op(ilp
->ins
);
283 if (op
== BC_ISTC
|| op
== BC_ISFC
) {
284 if (reg
!= NO_REG
&& reg
!= bc_d(ilp
->ins
)) {
285 setbc_a(&ilp
->ins
, reg
);
286 } else { /* Nothing to store or already in the right register. */
287 setbc_op(&ilp
->ins
, op
+(BC_IST
-BC_ISTC
));
288 setbc_a(&ilp
->ins
, 0);
290 } else if (bc_a(ilp
->ins
) == NO_REG
) {
292 ilp
->ins
= BCINS_AJ(BC_JMP
, bc_a(fs
->bcbase
[pc
].ins
), 0);
294 setbc_a(&ilp
->ins
, reg
);
295 if (reg
>= bc_a(ilp
[1].ins
))
296 setbc_a(&ilp
[1].ins
, reg
+1);
299 return 0; /* Cannot patch other instructions. */
304 /* Drop values for all instructions on jump list. */
305 static void jmp_dropval(FuncState
*fs
, BCPos list
)
307 for (; list
!= NO_JMP
; list
= jmp_next(fs
, list
))
308 jmp_patchtestreg(fs
, list
, NO_REG
);
311 /* Patch jump instruction to target. */
312 static void jmp_patchins(FuncState
*fs
, BCPos pc
, BCPos dest
)
314 BCIns
*jmp
= &fs
->bcbase
[pc
].ins
;
315 BCPos offset
= dest
-(pc
+1)+BCBIAS_J
;
316 lua_assert(dest
!= NO_JMP
);
317 if (offset
> BCMAX_D
)
318 err_syntax(fs
->ls
, LJ_ERR_XJUMP
);
319 setbc_d(jmp
, offset
);
322 /* Append to jump list. */
323 static void jmp_append(FuncState
*fs
, BCPos
*l1
, BCPos l2
)
327 } else if (*l1
== NO_JMP
) {
332 while ((next
= jmp_next(fs
, list
)) != NO_JMP
) /* Find last element. */
334 jmp_patchins(fs
, list
, l2
);
338 /* Patch jump list and preserve produced values. */
339 static void jmp_patchval(FuncState
*fs
, BCPos list
, BCPos vtarget
,
340 BCReg reg
, BCPos dtarget
)
342 while (list
!= NO_JMP
) {
343 BCPos next
= jmp_next(fs
, list
);
344 if (jmp_patchtestreg(fs
, list
, reg
))
345 jmp_patchins(fs
, list
, vtarget
); /* Jump to target with value. */
347 jmp_patchins(fs
, list
, dtarget
); /* Jump to default target. */
352 /* Jump to following instruction. Append to list of pending jumps. */
353 static void jmp_tohere(FuncState
*fs
, BCPos list
)
355 fs
->lasttarget
= fs
->pc
;
356 jmp_append(fs
, &fs
->jpc
, list
);
359 /* Patch jump list to target. */
360 static void jmp_patch(FuncState
*fs
, BCPos list
, BCPos target
)
362 if (target
== fs
->pc
) {
363 jmp_tohere(fs
, list
);
365 lua_assert(target
< fs
->pc
);
366 jmp_patchval(fs
, list
, target
, NO_REG
, target
);
370 /* -- Bytecode register allocator ----------------------------------------- */
372 /* Bump frame size. */
373 static void bcreg_bump(FuncState
*fs
, BCReg n
)
375 BCReg sz
= fs
->freereg
+ n
;
376 if (sz
> fs
->framesize
) {
377 if (sz
>= LJ_MAX_SLOTS
)
378 err_syntax(fs
->ls
, LJ_ERR_XSLOTS
);
379 fs
->framesize
= (uint8_t)sz
;
383 /* Reserve registers. */
384 static void bcreg_reserve(FuncState
*fs
, BCReg n
)
391 static void bcreg_free(FuncState
*fs
, BCReg reg
)
393 if (reg
>= fs
->nactvar
) {
395 lua_assert(reg
== fs
->freereg
);
399 /* Free register for expression. */
400 static void expr_free(FuncState
*fs
, ExpDesc
*e
)
402 if (e
->k
== VNONRELOC
)
403 bcreg_free(fs
, e
->u
.s
.info
);
406 /* -- Bytecode emitter ---------------------------------------------------- */
408 /* Emit bytecode instruction. */
409 static BCPos
bcemit_INS(FuncState
*fs
, BCIns ins
)
412 LexState
*ls
= fs
->ls
;
413 jmp_patchval(fs
, fs
->jpc
, pc
, NO_REG
, pc
);
415 if (LJ_UNLIKELY(pc
>= fs
->bclim
)) {
416 ptrdiff_t base
= fs
->bcbase
- ls
->bcstack
;
417 checklimit(fs
, ls
->sizebcstack
, LJ_MAX_BCINS
, "bytecode instructions");
418 lj_mem_growvec(fs
->L
, ls
->bcstack
, ls
->sizebcstack
, LJ_MAX_BCINS
,BCInsLine
);
419 fs
->bclim
= (BCPos
)(ls
->sizebcstack
- base
);
420 fs
->bcbase
= ls
->bcstack
+ base
;
422 fs
->bcbase
[pc
].ins
= ins
;
423 fs
->bcbase
[pc
].line
= ls
->lastline
;
428 #define bcemit_ABC(fs, o, a, b, c) bcemit_INS(fs, BCINS_ABC(o, a, b, c))
429 #define bcemit_AD(fs, o, a, d) bcemit_INS(fs, BCINS_AD(o, a, d))
430 #define bcemit_AJ(fs, o, a, j) bcemit_INS(fs, BCINS_AJ(o, a, j))
432 #define bcptr(fs, e) (&(fs)->bcbase[(e)->u.s.info].ins)
434 /* -- Bytecode emitter for expressions ------------------------------------ */
436 /* Discharge non-constant expression to any register. */
437 static void expr_discharge(FuncState
*fs
, ExpDesc
*e
)
440 if (e
->k
== VUPVAL
) {
441 ins
= BCINS_AD(BC_UGET
, 0, e
->u
.s
.info
);
442 } else if (e
->k
== VGLOBAL
) {
443 ins
= BCINS_AD(BC_GGET
, 0, const_str(fs
, e
));
444 } else if (e
->k
== VINDEXED
) {
445 BCReg rc
= e
->u
.s
.aux
;
446 if ((int32_t)rc
< 0) {
447 ins
= BCINS_ABC(BC_TGETS
, 0, e
->u
.s
.info
, ~rc
);
448 } else if (rc
> BCMAX_C
) {
449 ins
= BCINS_ABC(BC_TGETB
, 0, e
->u
.s
.info
, rc
-(BCMAX_C
+1));
452 ins
= BCINS_ABC(BC_TGETV
, 0, e
->u
.s
.info
, rc
);
454 bcreg_free(fs
, e
->u
.s
.info
);
455 } else if (e
->k
== VCALL
) {
456 e
->u
.s
.info
= e
->u
.s
.aux
;
459 } else if (e
->k
== VLOCAL
) {
465 e
->u
.s
.info
= bcemit_INS(fs
, ins
);
469 /* Emit bytecode to set a range of registers to nil. */
470 static void bcemit_nil(FuncState
*fs
, BCReg from
, BCReg n
)
472 if (fs
->pc
> fs
->lasttarget
) { /* No jumps to current position? */
473 BCIns
*ip
= &fs
->bcbase
[fs
->pc
-1].ins
;
474 BCReg pto
, pfrom
= bc_a(*ip
);
475 switch (bc_op(*ip
)) { /* Try to merge with the previous instruction. */
477 if (bc_d(*ip
) != ~LJ_TNIL
) break;
480 } else if (from
== pfrom
+1) {
486 *ip
= BCINS_AD(BC_KNIL
, from
, from
+n
-1); /* Replace KPRI. */
490 if (pfrom
<= from
&& from
<= pto
+1) { /* Can we connect both ranges? */
492 setbc_d(ip
, from
+n
-1); /* Patch previous instruction range. */
500 /* Emit new instruction or replace old instruction. */
501 bcemit_INS(fs
, n
== 1 ? BCINS_AD(BC_KPRI
, from
, VKNIL
) :
502 BCINS_AD(BC_KNIL
, from
, from
+n
-1));
505 /* Discharge an expression to a specific register. Ignore branches. */
506 static void expr_toreg_nobranch(FuncState
*fs
, ExpDesc
*e
, BCReg reg
)
509 expr_discharge(fs
, e
);
511 ins
= BCINS_AD(BC_KSTR
, reg
, const_str(fs
, e
));
512 } else if (e
->k
== VKNUM
) {
514 cTValue
*tv
= expr_numtv(e
);
515 if (tvisint(tv
) && checki16(intV(tv
)))
516 ins
= BCINS_AD(BC_KSHORT
, reg
, (BCReg
)(uint16_t)intV(tv
));
519 lua_Number n
= expr_numberV(e
);
520 int32_t k
= lj_num2int(n
);
521 if (checki16(k
) && n
== (lua_Number
)k
)
522 ins
= BCINS_AD(BC_KSHORT
, reg
, (BCReg
)(uint16_t)k
);
525 ins
= BCINS_AD(BC_KNUM
, reg
, const_num(fs
, e
));
527 } else if (e
->k
== VKCDATA
) {
528 fs
->flags
|= PROTO_FFI
;
529 ins
= BCINS_AD(BC_KCDATA
, reg
,
530 const_gc(fs
, obj2gco(cdataV(&e
->u
.nval
)), LJ_TCDATA
));
532 } else if (e
->k
== VRELOCABLE
) {
533 setbc_a(bcptr(fs
, e
), reg
);
535 } else if (e
->k
== VNONRELOC
) {
536 if (reg
== e
->u
.s
.info
)
538 ins
= BCINS_AD(BC_MOV
, reg
, e
->u
.s
.info
);
539 } else if (e
->k
== VKNIL
) {
540 bcemit_nil(fs
, reg
, 1);
542 } else if (e
->k
<= VKTRUE
) {
543 ins
= BCINS_AD(BC_KPRI
, reg
, const_pri(e
));
545 lua_assert(e
->k
== VVOID
|| e
->k
== VJMP
);
554 /* Forward declaration. */
555 static BCPos
bcemit_jmp(FuncState
*fs
);
557 /* Discharge an expression to a specific register. */
558 static void expr_toreg(FuncState
*fs
, ExpDesc
*e
, BCReg reg
)
560 expr_toreg_nobranch(fs
, e
, reg
);
562 jmp_append(fs
, &e
->t
, e
->u
.s
.info
); /* Add it to the true jump list. */
563 if (expr_hasjump(e
)) { /* Discharge expression with branches. */
564 BCPos jend
, jfalse
= NO_JMP
, jtrue
= NO_JMP
;
565 if (jmp_novalue(fs
, e
->t
) || jmp_novalue(fs
, e
->f
)) {
566 BCPos jval
= (e
->k
== VJMP
) ? NO_JMP
: bcemit_jmp(fs
);
567 jfalse
= bcemit_AD(fs
, BC_KPRI
, reg
, VKFALSE
);
568 bcemit_AJ(fs
, BC_JMP
, fs
->freereg
, 1);
569 jtrue
= bcemit_AD(fs
, BC_KPRI
, reg
, VKTRUE
);
570 jmp_tohere(fs
, jval
);
573 fs
->lasttarget
= jend
;
574 jmp_patchval(fs
, e
->f
, jend
, reg
, jfalse
);
575 jmp_patchval(fs
, e
->t
, jend
, reg
, jtrue
);
577 e
->f
= e
->t
= NO_JMP
;
582 /* Discharge an expression to the next free register. */
583 static void expr_tonextreg(FuncState
*fs
, ExpDesc
*e
)
585 expr_discharge(fs
, e
);
587 bcreg_reserve(fs
, 1);
588 expr_toreg(fs
, e
, fs
->freereg
- 1);
591 /* Discharge an expression to any register. */
592 static BCReg
expr_toanyreg(FuncState
*fs
, ExpDesc
*e
)
594 expr_discharge(fs
, e
);
595 if (e
->k
== VNONRELOC
) {
596 if (!expr_hasjump(e
)) return e
->u
.s
.info
; /* Already in a register. */
597 if (e
->u
.s
.info
>= fs
->nactvar
) {
598 expr_toreg(fs
, e
, e
->u
.s
.info
); /* Discharge to temp. register. */
602 expr_tonextreg(fs
, e
); /* Discharge to next register. */
606 /* Partially discharge expression to a value. */
607 static void expr_toval(FuncState
*fs
, ExpDesc
*e
)
610 expr_toanyreg(fs
, e
);
612 expr_discharge(fs
, e
);
615 /* Emit store for LHS expression. */
616 static void bcemit_store(FuncState
*fs
, ExpDesc
*var
, ExpDesc
*e
)
619 if (var
->k
== VLOCAL
) {
620 fs
->ls
->vstack
[var
->u
.s
.aux
].info
|= VSTACK_VAR_RW
;
622 expr_toreg(fs
, e
, var
->u
.s
.info
);
624 } else if (var
->k
== VUPVAL
) {
625 fs
->ls
->vstack
[var
->u
.s
.aux
].info
|= VSTACK_VAR_RW
;
628 ins
= BCINS_AD(BC_USETP
, var
->u
.s
.info
, const_pri(e
));
629 else if (e
->k
== VKSTR
)
630 ins
= BCINS_AD(BC_USETS
, var
->u
.s
.info
, const_str(fs
, e
));
631 else if (e
->k
== VKNUM
)
632 ins
= BCINS_AD(BC_USETN
, var
->u
.s
.info
, const_num(fs
, e
));
634 ins
= BCINS_AD(BC_USETV
, var
->u
.s
.info
, expr_toanyreg(fs
, e
));
635 } else if (var
->k
== VGLOBAL
) {
636 BCReg ra
= expr_toanyreg(fs
, e
);
637 ins
= BCINS_AD(BC_GSET
, ra
, const_str(fs
, var
));
640 lua_assert(var
->k
== VINDEXED
);
641 ra
= expr_toanyreg(fs
, e
);
643 if ((int32_t)rc
< 0) {
644 ins
= BCINS_ABC(BC_TSETS
, ra
, var
->u
.s
.info
, ~rc
);
645 } else if (rc
> BCMAX_C
) {
646 ins
= BCINS_ABC(BC_TSETB
, ra
, var
->u
.s
.info
, rc
-(BCMAX_C
+1));
648 /* Free late alloced key reg to avoid assert on free of value reg. */
649 /* This can only happen when called from expr_table(). */
650 lua_assert(e
->k
!= VNONRELOC
|| ra
< fs
->nactvar
||
651 rc
< ra
|| (bcreg_free(fs
, rc
),1));
652 ins
= BCINS_ABC(BC_TSETV
, ra
, var
->u
.s
.info
, rc
);
659 /* Emit method lookup expression. */
660 static void bcemit_method(FuncState
*fs
, ExpDesc
*e
, ExpDesc
*key
)
662 BCReg idx
, func
, obj
= expr_toanyreg(fs
, e
);
665 bcemit_AD(fs
, BC_MOV
, func
+1, obj
); /* Copy object to first argument. */
666 lua_assert(expr_isstrk(key
));
667 idx
= const_str(fs
, key
);
668 if (idx
<= BCMAX_C
) {
669 bcreg_reserve(fs
, 2);
670 bcemit_ABC(fs
, BC_TGETS
, func
, obj
, idx
);
672 bcreg_reserve(fs
, 3);
673 bcemit_AD(fs
, BC_KSTR
, func
+2, idx
);
674 bcemit_ABC(fs
, BC_TGETV
, func
, obj
, func
+2);
681 /* -- Bytecode emitter for branches --------------------------------------- */
683 /* Emit unconditional branch. */
684 static BCPos
bcemit_jmp(FuncState
*fs
)
687 BCPos j
= fs
->pc
- 1;
688 BCIns
*ip
= &fs
->bcbase
[j
].ins
;
690 if ((int32_t)j
>= (int32_t)fs
->lasttarget
&& bc_op(*ip
) == BC_UCLO
)
693 j
= bcemit_AJ(fs
, BC_JMP
, fs
->freereg
, NO_JMP
);
694 jmp_append(fs
, &j
, jpc
);
698 /* Invert branch condition of bytecode instruction. */
699 static void invertcond(FuncState
*fs
, ExpDesc
*e
)
701 BCIns
*ip
= &fs
->bcbase
[e
->u
.s
.info
- 1].ins
;
702 setbc_op(ip
, bc_op(*ip
)^1);
705 /* Emit conditional branch. */
706 static BCPos
bcemit_branch(FuncState
*fs
, ExpDesc
*e
, int cond
)
709 if (e
->k
== VRELOCABLE
) {
710 BCIns
*ip
= bcptr(fs
, e
);
711 if (bc_op(*ip
) == BC_NOT
) {
712 *ip
= BCINS_AD(cond
? BC_ISF
: BC_IST
, 0, bc_d(*ip
));
713 return bcemit_jmp(fs
);
716 if (e
->k
!= VNONRELOC
) {
717 bcreg_reserve(fs
, 1);
718 expr_toreg_nobranch(fs
, e
, fs
->freereg
-1);
720 bcemit_AD(fs
, cond
? BC_ISTC
: BC_ISFC
, NO_REG
, e
->u
.s
.info
);
726 /* Emit branch on true condition. */
727 static void bcemit_branch_t(FuncState
*fs
, ExpDesc
*e
)
730 expr_discharge(fs
, e
);
731 if (e
->k
== VKSTR
|| e
->k
== VKNUM
|| e
->k
== VKTRUE
)
732 pc
= NO_JMP
; /* Never jump. */
733 else if (e
->k
== VJMP
)
734 invertcond(fs
, e
), pc
= e
->u
.s
.info
;
735 else if (e
->k
== VKFALSE
|| e
->k
== VKNIL
)
736 expr_toreg_nobranch(fs
, e
, NO_REG
), pc
= bcemit_jmp(fs
);
738 pc
= bcemit_branch(fs
, e
, 0);
739 jmp_append(fs
, &e
->f
, pc
);
740 jmp_tohere(fs
, e
->t
);
744 /* Emit branch on false condition. */
745 static void bcemit_branch_f(FuncState
*fs
, ExpDesc
*e
)
748 expr_discharge(fs
, e
);
749 if (e
->k
== VKNIL
|| e
->k
== VKFALSE
)
750 pc
= NO_JMP
; /* Never jump. */
751 else if (e
->k
== VJMP
)
753 else if (e
->k
== VKSTR
|| e
->k
== VKNUM
|| e
->k
== VKTRUE
)
754 expr_toreg_nobranch(fs
, e
, NO_REG
), pc
= bcemit_jmp(fs
);
756 pc
= bcemit_branch(fs
, e
, 1);
757 jmp_append(fs
, &e
->t
, pc
);
758 jmp_tohere(fs
, e
->f
);
762 /* -- Bytecode emitter for operators -------------------------------------- */
764 /* Try constant-folding of arithmetic operators. */
765 static int foldarith(BinOpr opr
, ExpDesc
*e1
, ExpDesc
*e2
)
769 if (!expr_isnumk_nojump(e1
) || !expr_isnumk_nojump(e2
)) return 0;
770 n
= lj_vm_foldarith(expr_numberV(e1
), expr_numberV(e2
), (int)opr
-OPR_ADD
);
772 if (tvisnan(&o
) || tvismzero(&o
)) return 0; /* Avoid NaN and -0 as consts. */
774 int32_t k
= lj_num2int(n
);
775 if ((lua_Number
)k
== n
) {
776 setintV(&e1
->u
.nval
, k
);
780 setnumV(&e1
->u
.nval
, n
);
784 /* Emit arithmetic operator. */
785 static void bcemit_arith(FuncState
*fs
, BinOpr opr
, ExpDesc
*e1
, ExpDesc
*e2
)
789 if (foldarith(opr
, e1
, e2
))
791 if (opr
== OPR_POW
) {
793 rc
= expr_toanyreg(fs
, e2
);
794 rb
= expr_toanyreg(fs
, e1
);
796 op
= opr
-OPR_ADD
+BC_ADDVV
;
797 /* Must discharge 2nd operand first since VINDEXED might free regs. */
799 if (expr_isnumk(e2
) && (rc
= const_num(fs
, e2
)) <= BCMAX_C
)
800 op
-= BC_ADDVV
-BC_ADDVN
;
802 rc
= expr_toanyreg(fs
, e2
);
803 /* 1st operand discharged by bcemit_binop_left, but need KNUM/KSHORT. */
804 lua_assert(expr_isnumk(e1
) || e1
->k
== VNONRELOC
);
806 /* Avoid two consts to satisfy bytecode constraints. */
807 if (expr_isnumk(e1
) && !expr_isnumk(e2
) &&
808 (t
= const_num(fs
, e1
)) <= BCMAX_B
) {
809 rb
= rc
; rc
= t
; op
-= BC_ADDVV
-BC_ADDNV
;
811 rb
= expr_toanyreg(fs
, e1
);
814 /* Using expr_free might cause asserts if the order is wrong. */
815 if (e1
->k
== VNONRELOC
&& e1
->u
.s
.info
>= fs
->nactvar
) fs
->freereg
--;
816 if (e2
->k
== VNONRELOC
&& e2
->u
.s
.info
>= fs
->nactvar
) fs
->freereg
--;
817 e1
->u
.s
.info
= bcemit_ABC(fs
, op
, 0, rb
, rc
);
821 /* Emit comparison operator. */
822 static void bcemit_comp(FuncState
*fs
, BinOpr opr
, ExpDesc
*e1
, ExpDesc
*e2
)
827 if (opr
== OPR_EQ
|| opr
== OPR_NE
) {
828 BCOp op
= opr
== OPR_EQ
? BC_ISEQV
: BC_ISNEV
;
830 if (expr_isk(e1
)) { e1
= e2
; e2
= eret
; } /* Need constant in 2nd arg. */
831 ra
= expr_toanyreg(fs
, e1
); /* First arg must be in a reg. */
834 case VKNIL
: case VKFALSE
: case VKTRUE
:
835 ins
= BCINS_AD(op
+(BC_ISEQP
-BC_ISEQV
), ra
, const_pri(e2
));
838 ins
= BCINS_AD(op
+(BC_ISEQS
-BC_ISEQV
), ra
, const_str(fs
, e2
));
841 ins
= BCINS_AD(op
+(BC_ISEQN
-BC_ISEQV
), ra
, const_num(fs
, e2
));
844 ins
= BCINS_AD(op
, ra
, expr_toanyreg(fs
, e2
));
848 uint32_t op
= opr
-OPR_LT
+BC_ISLT
;
850 if ((op
-BC_ISLT
) & 1) { /* GT -> LT, GE -> LE */
851 e1
= e2
; e2
= eret
; /* Swap operands. */
852 op
= ((op
-BC_ISLT
)^3)+BC_ISLT
;
855 rd
= expr_toanyreg(fs
, e2
);
856 ra
= expr_toanyreg(fs
, e1
);
857 ins
= BCINS_AD(op
, ra
, rd
);
859 /* Using expr_free might cause asserts if the order is wrong. */
860 if (e1
->k
== VNONRELOC
&& e1
->u
.s
.info
>= fs
->nactvar
) fs
->freereg
--;
861 if (e2
->k
== VNONRELOC
&& e2
->u
.s
.info
>= fs
->nactvar
) fs
->freereg
--;
863 eret
->u
.s
.info
= bcemit_jmp(fs
);
867 /* Fixup left side of binary operator. */
868 static void bcemit_binop_left(FuncState
*fs
, BinOpr op
, ExpDesc
*e
)
871 bcemit_branch_t(fs
, e
);
872 } else if (op
== OPR_OR
) {
873 bcemit_branch_f(fs
, e
);
874 } else if (op
== OPR_CONCAT
) {
875 expr_tonextreg(fs
, e
);
876 } else if (op
== OPR_EQ
|| op
== OPR_NE
) {
877 if (!expr_isk_nojump(e
)) expr_toanyreg(fs
, e
);
879 if (!expr_isnumk_nojump(e
)) expr_toanyreg(fs
, e
);
883 /* Emit binary operator. */
884 static void bcemit_binop(FuncState
*fs
, BinOpr op
, ExpDesc
*e1
, ExpDesc
*e2
)
887 bcemit_arith(fs
, op
, e1
, e2
);
888 } else if (op
== OPR_AND
) {
889 lua_assert(e1
->t
== NO_JMP
); /* List must be closed. */
890 expr_discharge(fs
, e2
);
891 jmp_append(fs
, &e2
->f
, e1
->f
);
893 } else if (op
== OPR_OR
) {
894 lua_assert(e1
->f
== NO_JMP
); /* List must be closed. */
895 expr_discharge(fs
, e2
);
896 jmp_append(fs
, &e2
->t
, e1
->t
);
898 } else if (op
== OPR_CONCAT
) {
900 if (e2
->k
== VRELOCABLE
&& bc_op(*bcptr(fs
, e2
)) == BC_CAT
) {
901 lua_assert(e1
->u
.s
.info
== bc_b(*bcptr(fs
, e2
))-1);
903 setbc_b(bcptr(fs
, e2
), e1
->u
.s
.info
);
904 e1
->u
.s
.info
= e2
->u
.s
.info
;
906 expr_tonextreg(fs
, e2
);
909 e1
->u
.s
.info
= bcemit_ABC(fs
, BC_CAT
, 0, e1
->u
.s
.info
, e2
->u
.s
.info
);
913 lua_assert(op
== OPR_NE
|| op
== OPR_EQ
||
914 op
== OPR_LT
|| op
== OPR_GE
|| op
== OPR_LE
|| op
== OPR_GT
);
915 bcemit_comp(fs
, op
, e1
, e2
);
919 /* Emit unary operator. */
920 static void bcemit_unop(FuncState
*fs
, BCOp op
, ExpDesc
*e
)
923 /* Swap true and false lists. */
924 { BCPos temp
= e
->f
; e
->f
= e
->t
; e
->t
= temp
; }
925 jmp_dropval(fs
, e
->f
);
926 jmp_dropval(fs
, e
->t
);
927 expr_discharge(fs
, e
);
928 if (e
->k
== VKNIL
|| e
->k
== VKFALSE
) {
931 } else if (expr_isk(e
) || (LJ_HASFFI
&& e
->k
== VKCDATA
)) {
934 } else if (e
->k
== VJMP
) {
937 } else if (e
->k
== VRELOCABLE
) {
938 bcreg_reserve(fs
, 1);
939 setbc_a(bcptr(fs
, e
), fs
->freereg
-1);
940 e
->u
.s
.info
= fs
->freereg
-1;
943 lua_assert(e
->k
== VNONRELOC
);
946 lua_assert(op
== BC_UNM
|| op
== BC_LEN
);
947 if (op
== BC_UNM
&& !expr_hasjump(e
)) { /* Constant-fold negations. */
949 if (e
->k
== VKCDATA
) { /* Fold in-place since cdata is not interned. */
950 GCcdata
*cd
= cdataV(&e
->u
.nval
);
951 int64_t *p
= (int64_t *)cdataptr(cd
);
952 if (cd
->ctypeid
== CTID_COMPLEX_DOUBLE
)
953 p
[1] ^= (int64_t)U64x(80000000,00000000);
959 if (expr_isnumk(e
) && !expr_numiszero(e
)) { /* Avoid folding to -0. */
960 TValue
*o
= expr_numtv(e
);
964 setnumV(o
, -(lua_Number
)k
);
969 o
->u64
^= U64x(80000000,00000000);
974 expr_toanyreg(fs
, e
);
977 e
->u
.s
.info
= bcemit_AD(fs
, op
, 0, e
->u
.s
.info
);
981 /* -- Lexer support ------------------------------------------------------- */
983 /* Check and consume optional token. */
984 static int lex_opt(LexState
*ls
, LexToken tok
)
986 if (ls
->tok
== tok
) {
993 /* Check and consume token. */
994 static void lex_check(LexState
*ls
, LexToken tok
)
1001 /* Check for matching token. */
1002 static void lex_match(LexState
*ls
, LexToken what
, LexToken who
, BCLine line
)
1004 if (!lex_opt(ls
, what
)) {
1005 if (line
== ls
->linenumber
) {
1006 err_token(ls
, what
);
1008 const char *swhat
= lj_lex_token2str(ls
, what
);
1009 const char *swho
= lj_lex_token2str(ls
, who
);
1010 lj_lex_error(ls
, ls
->tok
, LJ_ERR_XMATCH
, swhat
, swho
, line
);
1015 /* Check for string token. */
1016 static GCstr
*lex_str(LexState
*ls
)
1019 if (ls
->tok
!= TK_name
&& (LJ_52
|| ls
->tok
!= TK_goto
))
1020 err_token(ls
, TK_name
);
1021 s
= strV(&ls
->tokval
);
1026 /* -- Variable handling --------------------------------------------------- */
1028 #define var_get(ls, fs, i) ((ls)->vstack[(fs)->varmap[(i)]])
1030 /* Define a new local variable. */
1031 static void var_new(LexState
*ls
, BCReg n
, GCstr
*name
)
1033 FuncState
*fs
= ls
->fs
;
1034 MSize vtop
= ls
->vtop
;
1035 checklimit(fs
, fs
->nactvar
+n
, LJ_MAX_LOCVAR
, "local variables");
1036 if (LJ_UNLIKELY(vtop
>= ls
->sizevstack
)) {
1037 if (ls
->sizevstack
>= LJ_MAX_VSTACK
)
1038 lj_lex_error(ls
, 0, LJ_ERR_XLIMC
, LJ_MAX_VSTACK
);
1039 lj_mem_growvec(ls
->L
, ls
->vstack
, ls
->sizevstack
, LJ_MAX_VSTACK
, VarInfo
);
1041 lua_assert((uintptr_t)name
< VARNAME__MAX
||
1042 lj_tab_getstr(fs
->kt
, name
) != NULL
);
1043 /* NOBARRIER: name is anchored in fs->kt and ls->vstack is not a GCobj. */
1044 setgcref(ls
->vstack
[vtop
].name
, obj2gco(name
));
1045 fs
->varmap
[fs
->nactvar
+n
] = (uint16_t)vtop
;
1049 #define var_new_lit(ls, n, v) \
1050 var_new(ls, (n), lj_parse_keepstr(ls, "" v, sizeof(v)-1))
1052 #define var_new_fixed(ls, n, vn) \
1053 var_new(ls, (n), (GCstr *)(uintptr_t)(vn))
1055 /* Add local variables. */
1056 static void var_add(LexState
*ls
, BCReg nvars
)
1058 FuncState
*fs
= ls
->fs
;
1059 BCReg nactvar
= fs
->nactvar
;
1061 VarInfo
*v
= &var_get(ls
, fs
, nactvar
);
1062 v
->startpc
= fs
->pc
;
1063 v
->slot
= nactvar
++;
1066 fs
->nactvar
= nactvar
;
1069 /* Remove local variables. */
1070 static void var_remove(LexState
*ls
, BCReg tolevel
)
1072 FuncState
*fs
= ls
->fs
;
1073 while (fs
->nactvar
> tolevel
)
1074 var_get(ls
, fs
, --fs
->nactvar
).endpc
= fs
->pc
;
1077 /* Lookup local variable name. */
1078 static BCReg
var_lookup_local(FuncState
*fs
, GCstr
*n
)
1081 for (i
= fs
->nactvar
-1; i
>= 0; i
--) {
1082 if (n
== strref(var_get(fs
->ls
, fs
, i
).name
))
1085 return (BCReg
)-1; /* Not found. */
1088 /* Lookup or add upvalue index. */
1089 static MSize
var_lookup_uv(FuncState
*fs
, MSize vidx
, ExpDesc
*e
)
1091 MSize i
, n
= fs
->nuv
;
1092 for (i
= 0; i
< n
; i
++)
1093 if (fs
->uvmap
[i
] == vidx
)
1094 return i
; /* Already exists. */
1095 /* Otherwise create a new one. */
1096 checklimit(fs
, fs
->nuv
, LJ_MAX_UPVAL
, "upvalues");
1097 lua_assert(e
->k
== VLOCAL
|| e
->k
== VUPVAL
);
1098 fs
->uvmap
[n
] = (uint16_t)vidx
;
1099 fs
->uvtmp
[n
] = (uint16_t)(e
->k
== VLOCAL
? vidx
: LJ_MAX_VSTACK
+e
->u
.s
.info
);
1104 /* Forward declaration. */
1105 static void fscope_uvmark(FuncState
*fs
, BCReg level
);
1107 /* Recursively lookup variables in enclosing functions. */
1108 static MSize
var_lookup_(FuncState
*fs
, GCstr
*name
, ExpDesc
*e
, int first
)
1111 BCReg reg
= var_lookup_local(fs
, name
);
1112 if ((int32_t)reg
>= 0) { /* Local in this function? */
1113 expr_init(e
, VLOCAL
, reg
);
1115 fscope_uvmark(fs
, reg
); /* Scope now has an upvalue. */
1116 return (MSize
)(e
->u
.s
.aux
= (uint32_t)fs
->varmap
[reg
]);
1118 MSize vidx
= var_lookup_(fs
->prev
, name
, e
, 0); /* Var in outer func? */
1119 if ((int32_t)vidx
>= 0) { /* Yes, make it an upvalue here. */
1120 e
->u
.s
.info
= (uint8_t)var_lookup_uv(fs
, vidx
, e
);
1125 } else { /* Not found in any function, must be a global. */
1126 expr_init(e
, VGLOBAL
, 0);
1129 return (MSize
)-1; /* Global. */
1132 /* Lookup variable name. */
1133 #define var_lookup(ls, e) \
1134 var_lookup_((ls)->fs, lex_str(ls), (e), 1)
1136 /* -- Goto an label handling ---------------------------------------------- */
1138 /* Add a new goto or label. */
1139 static MSize
gola_new(LexState
*ls
, GCstr
*name
, uint8_t info
, BCPos pc
)
1141 FuncState
*fs
= ls
->fs
;
1142 MSize vtop
= ls
->vtop
;
1143 if (LJ_UNLIKELY(vtop
>= ls
->sizevstack
)) {
1144 if (ls
->sizevstack
>= LJ_MAX_VSTACK
)
1145 lj_lex_error(ls
, 0, LJ_ERR_XLIMC
, LJ_MAX_VSTACK
);
1146 lj_mem_growvec(ls
->L
, ls
->vstack
, ls
->sizevstack
, LJ_MAX_VSTACK
, VarInfo
);
1148 lua_assert(name
== NAME_BREAK
|| lj_tab_getstr(fs
->kt
, name
) != NULL
);
1149 /* NOBARRIER: name is anchored in fs->kt and ls->vstack is not a GCobj. */
1150 setgcref(ls
->vstack
[vtop
].name
, obj2gco(name
));
1151 ls
->vstack
[vtop
].startpc
= pc
;
1152 ls
->vstack
[vtop
].slot
= (uint8_t)fs
->nactvar
;
1153 ls
->vstack
[vtop
].info
= info
;
1158 #define gola_isgoto(v) ((v)->info & VSTACK_GOTO)
1159 #define gola_islabel(v) ((v)->info & VSTACK_LABEL)
1160 #define gola_isgotolabel(v) ((v)->info & (VSTACK_GOTO|VSTACK_LABEL))
1162 /* Patch goto to jump to label. */
1163 static void gola_patch(LexState
*ls
, VarInfo
*vg
, VarInfo
*vl
)
1165 FuncState
*fs
= ls
->fs
;
1166 BCPos pc
= vg
->startpc
;
1167 setgcrefnull(vg
->name
); /* Invalidate pending goto. */
1168 setbc_a(&fs
->bcbase
[pc
].ins
, vl
->slot
);
1169 jmp_patch(fs
, pc
, vl
->startpc
);
1172 /* Patch goto to close upvalues. */
1173 static void gola_close(LexState
*ls
, VarInfo
*vg
)
1175 FuncState
*fs
= ls
->fs
;
1176 BCPos pc
= vg
->startpc
;
1177 BCIns
*ip
= &fs
->bcbase
[pc
].ins
;
1178 lua_assert(gola_isgoto(vg
));
1179 lua_assert(bc_op(*ip
) == BC_JMP
|| bc_op(*ip
) == BC_UCLO
);
1180 setbc_a(ip
, vg
->slot
);
1181 if (bc_op(*ip
) == BC_JMP
) {
1182 BCPos next
= jmp_next(fs
, pc
);
1183 if (next
!= NO_JMP
) jmp_patch(fs
, next
, pc
); /* Jump to UCLO. */
1184 setbc_op(ip
, BC_UCLO
); /* Turn into UCLO. */
1185 setbc_j(ip
, NO_JMP
);
1189 /* Resolve pending forward gotos for label. */
1190 static void gola_resolve(LexState
*ls
, FuncScope
*bl
, MSize idx
)
1192 VarInfo
*vg
= ls
->vstack
+ bl
->vstart
;
1193 VarInfo
*vl
= ls
->vstack
+ idx
;
1194 for (; vg
< vl
; vg
++)
1195 if (gcrefeq(vg
->name
, vl
->name
) && gola_isgoto(vg
)) {
1196 if (vg
->slot
< vl
->slot
) {
1197 GCstr
*name
= strref(var_get(ls
, ls
->fs
, vg
->slot
).name
);
1198 lua_assert((uintptr_t)name
>= VARNAME__MAX
);
1199 ls
->linenumber
= ls
->fs
->bcbase
[vg
->startpc
].line
;
1200 lua_assert(strref(vg
->name
) != NAME_BREAK
);
1201 lj_lex_error(ls
, 0, LJ_ERR_XGSCOPE
,
1202 strdata(strref(vg
->name
)), strdata(name
));
1204 gola_patch(ls
, vg
, vl
);
1208 /* Fixup remaining gotos and labels for scope. */
1209 static void gola_fixup(LexState
*ls
, FuncScope
*bl
)
1211 VarInfo
*v
= ls
->vstack
+ bl
->vstart
;
1212 VarInfo
*ve
= ls
->vstack
+ ls
->vtop
;
1213 for (; v
< ve
; v
++) {
1214 GCstr
*name
= strref(v
->name
);
1215 if (name
!= NULL
) { /* Only consider remaining valid gotos/labels. */
1216 if (gola_islabel(v
)) {
1218 setgcrefnull(v
->name
); /* Invalidate label that goes out of scope. */
1219 for (vg
= v
+1; vg
< ve
; vg
++) /* Resolve pending backward gotos. */
1220 if (strref(vg
->name
) == name
&& gola_isgoto(vg
)) {
1221 if ((bl
->flags
&FSCOPE_UPVAL
) && vg
->slot
> v
->slot
)
1223 gola_patch(ls
, vg
, v
);
1225 } else if (gola_isgoto(v
)) {
1226 if (bl
->prev
) { /* Propagate goto or break to outer scope. */
1227 bl
->prev
->flags
|= name
== NAME_BREAK
? FSCOPE_BREAK
: FSCOPE_GOLA
;
1228 v
->slot
= bl
->nactvar
;
1229 if ((bl
->flags
& FSCOPE_UPVAL
))
1231 } else { /* No outer scope: undefined goto label or no loop. */
1232 ls
->linenumber
= ls
->fs
->bcbase
[v
->startpc
].line
;
1233 if (name
== NAME_BREAK
)
1234 lj_lex_error(ls
, 0, LJ_ERR_XBREAK
);
1236 lj_lex_error(ls
, 0, LJ_ERR_XLUNDEF
, strdata(name
));
1243 /* Find existing label. */
1244 static VarInfo
*gola_findlabel(LexState
*ls
, GCstr
*name
)
1246 VarInfo
*v
= ls
->vstack
+ ls
->fs
->bl
->vstart
;
1247 VarInfo
*ve
= ls
->vstack
+ ls
->vtop
;
1249 if (strref(v
->name
) == name
&& gola_islabel(v
))
1254 /* -- Scope handling ------------------------------------------------------ */
1256 /* Begin a scope. */
1257 static void fscope_begin(FuncState
*fs
, FuncScope
*bl
, int flags
)
1259 bl
->nactvar
= (uint8_t)fs
->nactvar
;
1261 bl
->vstart
= fs
->ls
->vtop
;
1264 lua_assert(fs
->freereg
== fs
->nactvar
);
1268 static void fscope_end(FuncState
*fs
)
1270 FuncScope
*bl
= fs
->bl
;
1271 LexState
*ls
= fs
->ls
;
1273 var_remove(ls
, bl
->nactvar
);
1274 fs
->freereg
= fs
->nactvar
;
1275 lua_assert(bl
->nactvar
== fs
->nactvar
);
1276 if ((bl
->flags
& (FSCOPE_UPVAL
|FSCOPE_NOCLOSE
)) == FSCOPE_UPVAL
)
1277 bcemit_AJ(fs
, BC_UCLO
, bl
->nactvar
, 0);
1278 if ((bl
->flags
& FSCOPE_BREAK
)) {
1279 if ((bl
->flags
& FSCOPE_LOOP
)) {
1280 MSize idx
= gola_new(ls
, NAME_BREAK
, VSTACK_LABEL
, fs
->pc
);
1281 ls
->vtop
= idx
; /* Drop break label immediately. */
1282 gola_resolve(ls
, bl
, idx
);
1284 } /* else: need the fixup step to propagate the breaks. */
1285 } else if (!(bl
->flags
& FSCOPE_GOLA
)) {
1291 /* Mark scope as having an upvalue. */
1292 static void fscope_uvmark(FuncState
*fs
, BCReg level
)
1295 for (bl
= fs
->bl
; bl
&& bl
->nactvar
> level
; bl
= bl
->prev
)
1298 bl
->flags
|= FSCOPE_UPVAL
;
1301 /* -- Function state management ------------------------------------------- */
1303 /* Fixup bytecode for prototype. */
1304 static void fs_fixup_bc(FuncState
*fs
, GCproto
*pt
, BCIns
*bc
, MSize n
)
1306 BCInsLine
*base
= fs
->bcbase
;
1309 bc
[0] = BCINS_AD((fs
->flags
& PROTO_VARARG
) ? BC_FUNCV
: BC_FUNCF
,
1311 for (i
= 1; i
< n
; i
++)
1312 bc
[i
] = base
[i
].ins
;
1315 /* Fixup upvalues for child prototype, step #2. */
1316 static void fs_fixup_uv2(FuncState
*fs
, GCproto
*pt
)
1318 VarInfo
*vstack
= fs
->ls
->vstack
;
1319 uint16_t *uv
= proto_uv(pt
);
1320 MSize i
, n
= pt
->sizeuv
;
1321 for (i
= 0; i
< n
; i
++) {
1322 VarIndex vidx
= uv
[i
];
1323 if (vidx
>= LJ_MAX_VSTACK
)
1324 uv
[i
] = vidx
- LJ_MAX_VSTACK
;
1325 else if ((vstack
[vidx
].info
& VSTACK_VAR_RW
))
1326 uv
[i
] = vstack
[vidx
].slot
| PROTO_UV_LOCAL
;
1328 uv
[i
] = vstack
[vidx
].slot
| PROTO_UV_LOCAL
| PROTO_UV_IMMUTABLE
;
1332 /* Fixup constants for prototype. */
1333 static void fs_fixup_k(FuncState
*fs
, GCproto
*pt
, void *kptr
)
1339 checklimitgt(fs
, fs
->nkn
, BCMAX_D
+1, "constants");
1340 checklimitgt(fs
, fs
->nkgc
, BCMAX_D
+1, "constants");
1341 setmref(pt
->k
, kptr
);
1342 pt
->sizekn
= fs
->nkn
;
1343 pt
->sizekgc
= fs
->nkgc
;
1345 array
= tvref(kt
->array
);
1346 for (i
= 0; i
< kt
->asize
; i
++)
1347 if (tvhaskslot(&array
[i
])) {
1348 TValue
*tv
= &((TValue
*)kptr
)[tvkslot(&array
[i
])];
1350 setintV(tv
, (int32_t)i
);
1352 setnumV(tv
, (lua_Number
)i
);
1354 node
= noderef(kt
->node
);
1356 for (i
= 0; i
<= hmask
; i
++) {
1358 if (tvhaskslot(&n
->val
)) {
1359 ptrdiff_t kidx
= (ptrdiff_t)tvkslot(&n
->val
);
1360 lua_assert(!tvisint(&n
->key
));
1361 if (tvisnum(&n
->key
)) {
1362 TValue
*tv
= &((TValue
*)kptr
)[kidx
];
1364 lua_Number nn
= numV(&n
->key
);
1365 int32_t k
= lj_num2int(nn
);
1366 lua_assert(!tvismzero(&n
->key
));
1367 if ((lua_Number
)k
== nn
)
1375 GCobj
*o
= gcV(&n
->key
);
1376 setgcref(((GCRef
*)kptr
)[~kidx
], o
);
1377 lj_gc_objbarrier(fs
->L
, pt
, o
);
1378 if (tvisproto(&n
->key
))
1379 fs_fixup_uv2(fs
, gco2pt(o
));
1385 /* Fixup upvalues for prototype, step #1. */
1386 static void fs_fixup_uv1(FuncState
*fs
, GCproto
*pt
, uint16_t *uv
)
1388 setmref(pt
->uv
, uv
);
1389 pt
->sizeuv
= fs
->nuv
;
1390 memcpy(uv
, fs
->uvtmp
, fs
->nuv
*sizeof(VarIndex
));
1393 #ifndef LUAJIT_DISABLE_DEBUGINFO
1394 /* Prepare lineinfo for prototype. */
1395 static size_t fs_prep_line(FuncState
*fs
, BCLine numline
)
1397 return (fs
->pc
-1) << (numline
< 256 ? 0 : numline
< 65536 ? 1 : 2);
1400 /* Fixup lineinfo for prototype. */
1401 static void fs_fixup_line(FuncState
*fs
, GCproto
*pt
,
1402 void *lineinfo
, BCLine numline
)
1404 BCInsLine
*base
= fs
->bcbase
+ 1;
1405 BCLine first
= fs
->linedefined
;
1406 MSize i
= 0, n
= fs
->pc
-1;
1407 pt
->firstline
= fs
->linedefined
;
1408 pt
->numline
= numline
;
1409 setmref(pt
->lineinfo
, lineinfo
);
1410 if (LJ_LIKELY(numline
< 256)) {
1411 uint8_t *li
= (uint8_t *)lineinfo
;
1413 BCLine delta
= base
[i
].line
- first
;
1414 lua_assert(delta
>= 0 && delta
< 256);
1415 li
[i
] = (uint8_t)delta
;
1417 } else if (LJ_LIKELY(numline
< 65536)) {
1418 uint16_t *li
= (uint16_t *)lineinfo
;
1420 BCLine delta
= base
[i
].line
- first
;
1421 lua_assert(delta
>= 0 && delta
< 65536);
1422 li
[i
] = (uint16_t)delta
;
1425 uint32_t *li
= (uint32_t *)lineinfo
;
1427 BCLine delta
= base
[i
].line
- first
;
1428 lua_assert(delta
>= 0);
1429 li
[i
] = (uint32_t)delta
;
1434 /* Prepare variable info for prototype. */
1435 static size_t fs_prep_var(LexState
*ls
, FuncState
*fs
, size_t *ofsvar
)
1437 VarInfo
*vs
=ls
->vstack
, *ve
;
1440 lj_buf_reset(&ls
->sb
); /* Copy to temp. string buffer. */
1441 /* Store upvalue names. */
1442 for (i
= 0, n
= fs
->nuv
; i
< n
; i
++) {
1443 GCstr
*s
= strref(vs
[fs
->uvmap
[i
]].name
);
1444 MSize len
= s
->len
+1;
1445 char *p
= lj_buf_more(&ls
->sb
, len
);
1446 p
= lj_buf_wmem(p
, strdata(s
), len
);
1447 setsbufP(&ls
->sb
, p
);
1449 *ofsvar
= sbuflen(&ls
->sb
);
1451 /* Store local variable names and compressed ranges. */
1452 for (ve
= vs
+ ls
->vtop
, vs
+= fs
->vbase
; vs
< ve
; vs
++) {
1453 if (!gola_isgotolabel(vs
)) {
1454 GCstr
*s
= strref(vs
->name
);
1457 if ((uintptr_t)s
< VARNAME__MAX
) {
1458 p
= lj_buf_more(&ls
->sb
, 1 + 2*5);
1459 *p
++ = (char)(uintptr_t)s
;
1461 MSize len
= s
->len
+1;
1462 p
= lj_buf_more(&ls
->sb
, len
+ 2*5);
1463 p
= lj_buf_wmem(p
, strdata(s
), len
);
1465 startpc
= vs
->startpc
;
1466 p
= lj_strfmt_wuleb128(p
, startpc
-lastpc
);
1467 p
= lj_strfmt_wuleb128(p
, vs
->endpc
-startpc
);
1468 setsbufP(&ls
->sb
, p
);
1472 lj_buf_putb(&ls
->sb
, '\0'); /* Terminator for varinfo. */
1473 return sbuflen(&ls
->sb
);
1476 /* Fixup variable info for prototype. */
1477 static void fs_fixup_var(LexState
*ls
, GCproto
*pt
, uint8_t *p
, size_t ofsvar
)
1479 setmref(pt
->uvinfo
, p
);
1480 setmref(pt
->varinfo
, (char *)p
+ ofsvar
);
1481 memcpy(p
, sbufB(&ls
->sb
), sbuflen(&ls
->sb
)); /* Copy from temp. buffer. */
1485 /* Initialize with empty debug info, if disabled. */
1486 #define fs_prep_line(fs, numline) (UNUSED(numline), 0)
1487 #define fs_fixup_line(fs, pt, li, numline) \
1488 pt->firstline = pt->numline = 0, setmref((pt)->lineinfo, NULL)
1489 #define fs_prep_var(ls, fs, ofsvar) (UNUSED(ofsvar), 0)
1490 #define fs_fixup_var(ls, pt, p, ofsvar) \
1491 setmref((pt)->uvinfo, NULL), setmref((pt)->varinfo, NULL)
1495 /* Check if bytecode op returns. */
1496 static int bcopisret(BCOp op
)
1499 case BC_CALLMT
: case BC_CALLT
:
1500 case BC_RETM
: case BC_RET
: case BC_RET0
: case BC_RET1
:
1507 /* Fixup return instruction for prototype. */
1508 static void fs_fixup_ret(FuncState
*fs
)
1510 BCPos lastpc
= fs
->pc
;
1511 if (lastpc
<= fs
->lasttarget
|| !bcopisret(bc_op(fs
->bcbase
[lastpc
-1].ins
))) {
1512 if ((fs
->bl
->flags
& FSCOPE_UPVAL
))
1513 bcemit_AJ(fs
, BC_UCLO
, 0, 0);
1514 bcemit_AD(fs
, BC_RET0
, 0, 1); /* Need final return. */
1516 fs
->bl
->flags
|= FSCOPE_NOCLOSE
; /* Handled above. */
1518 lua_assert(fs
->bl
== NULL
);
1519 /* May need to fixup returns encoded before first function was created. */
1520 if (fs
->flags
& PROTO_FIXUP_RETURN
) {
1522 for (pc
= 1; pc
< lastpc
; pc
++) {
1523 BCIns ins
= fs
->bcbase
[pc
].ins
;
1525 switch (bc_op(ins
)) {
1526 case BC_CALLMT
: case BC_CALLT
:
1527 case BC_RETM
: case BC_RET
: case BC_RET0
: case BC_RET1
:
1528 offset
= bcemit_INS(fs
, ins
); /* Copy original instruction. */
1529 fs
->bcbase
[offset
].line
= fs
->bcbase
[pc
].line
;
1530 offset
= offset
-(pc
+1)+BCBIAS_J
;
1531 if (offset
> BCMAX_D
)
1532 err_syntax(fs
->ls
, LJ_ERR_XFIXUP
);
1533 /* Replace with UCLO plus branch. */
1534 fs
->bcbase
[pc
].ins
= BCINS_AD(BC_UCLO
, 0, offset
);
1537 return; /* We're done. */
1545 /* Finish a FuncState and return the new prototype. */
1546 static GCproto
*fs_finish(LexState
*ls
, BCLine line
)
1548 lua_State
*L
= ls
->L
;
1549 FuncState
*fs
= ls
->fs
;
1550 BCLine numline
= line
- fs
->linedefined
;
1551 size_t sizept
, ofsk
, ofsuv
, ofsli
, ofsdbg
, ofsvar
;
1554 /* Apply final fixups. */
1557 /* Calculate total size of prototype including all colocated arrays. */
1558 sizept
= sizeof(GCproto
) + fs
->pc
*sizeof(BCIns
) + fs
->nkgc
*sizeof(GCRef
);
1559 sizept
= (sizept
+ sizeof(TValue
)-1) & ~(sizeof(TValue
)-1);
1560 ofsk
= sizept
; sizept
+= fs
->nkn
*sizeof(TValue
);
1561 ofsuv
= sizept
; sizept
+= ((fs
->nuv
+1)&~1)*2;
1562 ofsli
= sizept
; sizept
+= fs_prep_line(fs
, numline
);
1563 ofsdbg
= sizept
; sizept
+= fs_prep_var(ls
, fs
, &ofsvar
);
1565 /* Allocate prototype and initialize its fields. */
1566 pt
= (GCproto
*)lj_mem_newgco(L
, (MSize
)sizept
);
1567 pt
->gct
= ~LJ_TPROTO
;
1568 pt
->sizept
= (MSize
)sizept
;
1570 pt
->flags
= (uint8_t)(fs
->flags
& ~(PROTO_HAS_RETURN
|PROTO_FIXUP_RETURN
));
1571 pt
->numparams
= fs
->numparams
;
1572 pt
->framesize
= fs
->framesize
;
1573 setgcref(pt
->chunkname
, obj2gco(ls
->chunkname
));
1575 /* Close potentially uninitialized gap between bc and kgc. */
1576 *(uint32_t *)((char *)pt
+ ofsk
- sizeof(GCRef
)*(fs
->nkgc
+1)) = 0;
1577 fs_fixup_bc(fs
, pt
, (BCIns
*)((char *)pt
+ sizeof(GCproto
)), fs
->pc
);
1578 fs_fixup_k(fs
, pt
, (void *)((char *)pt
+ ofsk
));
1579 fs_fixup_uv1(fs
, pt
, (uint16_t *)((char *)pt
+ ofsuv
));
1580 fs_fixup_line(fs
, pt
, (void *)((char *)pt
+ ofsli
), numline
);
1581 fs_fixup_var(ls
, pt
, (uint8_t *)((char *)pt
+ ofsdbg
), ofsvar
);
1583 lj_vmevent_send(L
, BC
,
1584 setprotoV(L
, L
->top
++, pt
);
1587 L
->top
--; /* Pop table of constants. */
1588 ls
->vtop
= fs
->vbase
; /* Reset variable stack. */
1590 lua_assert(ls
->fs
!= NULL
|| ls
->tok
== TK_eof
);
1594 /* Initialize a new FuncState. */
1595 static void fs_init(LexState
*ls
, FuncState
*fs
)
1597 lua_State
*L
= ls
->L
;
1598 fs
->prev
= ls
->fs
; ls
->fs
= fs
; /* Append to list. */
1600 fs
->vbase
= ls
->vtop
;
1612 fs
->framesize
= 1; /* Minimum frame size. */
1613 fs
->kt
= lj_tab_new(L
, 0, 0);
1614 /* Anchor table of constants in stack to avoid being collected. */
1615 settabV(L
, L
->top
, fs
->kt
);
1619 /* -- Expressions --------------------------------------------------------- */
1621 /* Forward declaration. */
1622 static void expr(LexState
*ls
, ExpDesc
*v
);
1624 /* Return string expression. */
1625 static void expr_str(LexState
*ls
, ExpDesc
*e
)
1627 expr_init(e
, VKSTR
, 0);
1628 e
->u
.sval
= lex_str(ls
);
1631 /* Return index expression. */
1632 static void expr_index(FuncState
*fs
, ExpDesc
*t
, ExpDesc
*e
)
1634 /* Already called: expr_toval(fs, e). */
1636 if (expr_isnumk(e
)) {
1638 if (tvisint(expr_numtv(e
))) {
1639 int32_t k
= intV(expr_numtv(e
));
1641 t
->u
.s
.aux
= BCMAX_C
+1+(uint32_t)k
; /* 256..511: const byte key */
1646 lua_Number n
= expr_numberV(e
);
1647 int32_t k
= lj_num2int(n
);
1648 if (checku8(k
) && n
== (lua_Number
)k
) {
1649 t
->u
.s
.aux
= BCMAX_C
+1+(uint32_t)k
; /* 256..511: const byte key */
1653 } else if (expr_isstrk(e
)) {
1654 BCReg idx
= const_str(fs
, e
);
1655 if (idx
<= BCMAX_C
) {
1656 t
->u
.s
.aux
= ~idx
; /* -256..-1: const string key */
1660 t
->u
.s
.aux
= expr_toanyreg(fs
, e
); /* 0..255: register */
1663 /* Parse index expression with named field. */
1664 static void expr_field(LexState
*ls
, ExpDesc
*v
)
1666 FuncState
*fs
= ls
->fs
;
1668 expr_toanyreg(fs
, v
);
1669 lj_lex_next(ls
); /* Skip dot or colon. */
1671 expr_index(fs
, v
, &key
);
1674 /* Parse index expression with brackets. */
1675 static void expr_bracket(LexState
*ls
, ExpDesc
*v
)
1677 lj_lex_next(ls
); /* Skip '['. */
1679 expr_toval(ls
->fs
, v
);
1683 /* Get value of constant expression. */
1684 static void expr_kvalue(TValue
*v
, ExpDesc
*e
)
1686 if (e
->k
<= VKTRUE
) {
1687 setitype(v
, ~(uint32_t)e
->k
);
1688 } else if (e
->k
== VKSTR
) {
1689 setgcref(v
->gcr
, obj2gco(e
->u
.sval
));
1690 setitype(v
, LJ_TSTR
);
1692 lua_assert(tvisnumber(expr_numtv(e
)));
1693 *v
= *expr_numtv(e
);
1697 /* Parse table constructor expression. */
1698 static void expr_table(LexState
*ls
, ExpDesc
*e
)
1700 FuncState
*fs
= ls
->fs
;
1701 BCLine line
= ls
->linenumber
;
1703 int vcall
= 0, needarr
= 0, fixt
= 0;
1704 uint32_t narr
= 1; /* First array index. */
1705 uint32_t nhash
= 0; /* Number of hash entries. */
1706 BCReg freg
= fs
->freereg
;
1707 BCPos pc
= bcemit_AD(fs
, BC_TNEW
, freg
, 0);
1708 expr_init(e
, VNONRELOC
, freg
);
1709 bcreg_reserve(fs
, 1);
1712 while (ls
->tok
!= '}') {
1715 if (ls
->tok
== '[') {
1716 expr_bracket(ls
, &key
); /* Already calls expr_toval. */
1717 if (!expr_isk(&key
)) expr_index(fs
, e
, &key
);
1718 if (expr_isnumk(&key
) && expr_numiszero(&key
)) needarr
= 1; else nhash
++;
1720 } else if ((ls
->tok
== TK_name
|| (!LJ_52
&& ls
->tok
== TK_goto
)) &&
1721 lj_lex_lookahead(ls
) == '=') {
1726 expr_init(&key
, VKNUM
, 0);
1727 setintV(&key
.u
.nval
, (int)narr
);
1729 needarr
= vcall
= 1;
1732 if (expr_isk(&key
) && key
.k
!= VKNIL
&&
1733 (key
.k
== VKSTR
|| expr_isk_nojump(&val
))) {
1735 if (!t
) { /* Create template table on demand. */
1737 t
= lj_tab_new(fs
->L
, needarr
? narr
: 0, hsize2hbits(nhash
));
1738 kidx
= const_gc(fs
, obj2gco(t
), LJ_TTAB
);
1739 fs
->bcbase
[pc
].ins
= BCINS_AD(BC_TDUP
, freg
-1, kidx
);
1742 expr_kvalue(&k
, &key
);
1743 v
= lj_tab_set(fs
->L
, t
, &k
);
1744 lj_gc_anybarriert(fs
->L
, t
);
1745 if (expr_isk_nojump(&val
)) { /* Add const key/value to template table. */
1746 expr_kvalue(v
, &val
);
1747 } else { /* Otherwise create dummy string key (avoids lj_tab_newkey). */
1748 settabV(fs
->L
, v
, t
); /* Preserve key with table itself as value. */
1749 fixt
= 1; /* Fix this later, after all resizes. */
1754 if (val
.k
!= VCALL
) { expr_toanyreg(fs
, &val
); vcall
= 0; }
1755 if (expr_isk(&key
)) expr_index(fs
, e
, &key
);
1756 bcemit_store(fs
, e
, &val
);
1759 if (!lex_opt(ls
, ',') && !lex_opt(ls
, ';')) break;
1761 lex_match(ls
, '}', '{', line
);
1763 BCInsLine
*ilp
= &fs
->bcbase
[fs
->pc
-1];
1765 lua_assert(bc_a(ilp
->ins
) == freg
&&
1766 bc_op(ilp
->ins
) == (narr
> 256 ? BC_TSETV
: BC_TSETB
));
1767 expr_init(&en
, VKNUM
, 0);
1768 en
.u
.nval
.u32
.lo
= narr
-1;
1769 en
.u
.nval
.u32
.hi
= 0x43300000; /* Biased integer to avoid denormals. */
1770 if (narr
> 256) { fs
->pc
--; ilp
--; }
1771 ilp
->ins
= BCINS_AD(BC_TSETM
, freg
, const_num(fs
, &en
));
1772 setbc_b(&ilp
[-1].ins
, 0);
1774 if (pc
== fs
->pc
-1) { /* Make expr relocable if possible. */
1779 e
->k
= VNONRELOC
; /* May have been changed by expr_index. */
1781 if (!t
) { /* Construct TNEW RD: hhhhhaaaaaaaaaaa. */
1782 BCIns
*ip
= &fs
->bcbase
[pc
].ins
;
1783 if (!needarr
) narr
= 0;
1784 else if (narr
< 3) narr
= 3;
1785 else if (narr
> 0x7ff) narr
= 0x7ff;
1786 setbc_d(ip
, narr
|(hsize2hbits(nhash
)<<11));
1788 if (needarr
&& t
->asize
< narr
)
1789 lj_tab_reasize(fs
->L
, t
, narr
-1);
1790 if (fixt
) { /* Fix value for dummy keys in template table. */
1791 Node
*node
= noderef(t
->node
);
1792 uint32_t i
, hmask
= t
->hmask
;
1793 for (i
= 0; i
<= hmask
; i
++) {
1795 if (tvistab(&n
->val
)) {
1796 lua_assert(tabV(&n
->val
) == t
);
1797 setnilV(&n
->val
); /* Turn value into nil. */
1805 /* Parse function parameters. */
1806 static BCReg
parse_params(LexState
*ls
, int needself
)
1808 FuncState
*fs
= ls
->fs
;
1812 var_new_lit(ls
, nparams
++, "self");
1813 if (ls
->tok
!= ')') {
1815 if (ls
->tok
== TK_name
|| (!LJ_52
&& ls
->tok
== TK_goto
)) {
1816 var_new(ls
, nparams
++, lex_str(ls
));
1817 } else if (ls
->tok
== TK_dots
) {
1819 fs
->flags
|= PROTO_VARARG
;
1822 err_syntax(ls
, LJ_ERR_XPARAM
);
1824 } while (lex_opt(ls
, ','));
1826 var_add(ls
, nparams
);
1827 lua_assert(fs
->nactvar
== nparams
);
1828 bcreg_reserve(fs
, nparams
);
1833 /* Forward declaration. */
1834 static void parse_chunk(LexState
*ls
);
1836 /* Parse body of a function. */
1837 static void parse_body(LexState
*ls
, ExpDesc
*e
, int needself
, BCLine line
)
1839 FuncState fs
, *pfs
= ls
->fs
;
1842 ptrdiff_t oldbase
= pfs
->bcbase
- ls
->bcstack
;
1844 fscope_begin(&fs
, &bl
, 0);
1845 fs
.linedefined
= line
;
1846 fs
.numparams
= (uint8_t)parse_params(ls
, needself
);
1847 fs
.bcbase
= pfs
->bcbase
+ pfs
->pc
;
1848 fs
.bclim
= pfs
->bclim
- pfs
->pc
;
1849 bcemit_AD(&fs
, BC_FUNCF
, 0, 0); /* Placeholder. */
1851 if (ls
->tok
!= TK_end
) lex_match(ls
, TK_end
, TK_function
, line
);
1852 pt
= fs_finish(ls
, (ls
->lastline
= ls
->linenumber
));
1853 pfs
->bcbase
= ls
->bcstack
+ oldbase
; /* May have been reallocated. */
1854 pfs
->bclim
= (BCPos
)(ls
->sizebcstack
- oldbase
);
1855 /* Store new prototype in the constant array of the parent. */
1856 expr_init(e
, VRELOCABLE
,
1857 bcemit_AD(pfs
, BC_FNEW
, 0, const_gc(pfs
, obj2gco(pt
), LJ_TPROTO
)));
1859 pfs
->flags
|= (fs
.flags
& PROTO_FFI
);
1861 if (!(pfs
->flags
& PROTO_CHILD
)) {
1862 if (pfs
->flags
& PROTO_HAS_RETURN
)
1863 pfs
->flags
|= PROTO_FIXUP_RETURN
;
1864 pfs
->flags
|= PROTO_CHILD
;
1869 /* Parse expression list. Last expression is left open. */
1870 static BCReg
expr_list(LexState
*ls
, ExpDesc
*v
)
1874 while (lex_opt(ls
, ',')) {
1875 expr_tonextreg(ls
->fs
, v
);
1882 /* Parse function argument list. */
1883 static void parse_args(LexState
*ls
, ExpDesc
*e
)
1885 FuncState
*fs
= ls
->fs
;
1889 BCLine line
= ls
->linenumber
;
1890 if (ls
->tok
== '(') {
1892 if (line
!= ls
->lastline
)
1893 err_syntax(ls
, LJ_ERR_XAMBIG
);
1896 if (ls
->tok
== ')') { /* f(). */
1899 expr_list(ls
, &args
);
1900 if (args
.k
== VCALL
) /* f(a, b, g()) or f(a, b, ...). */
1901 setbc_b(bcptr(fs
, &args
), 0); /* Pass on multiple results. */
1903 lex_match(ls
, ')', '(', line
);
1904 } else if (ls
->tok
== '{') {
1905 expr_table(ls
, &args
);
1906 } else if (ls
->tok
== TK_string
) {
1907 expr_init(&args
, VKSTR
, 0);
1908 args
.u
.sval
= strV(&ls
->tokval
);
1911 err_syntax(ls
, LJ_ERR_XFUNARG
);
1912 return; /* Silence compiler. */
1914 lua_assert(e
->k
== VNONRELOC
);
1915 base
= e
->u
.s
.info
; /* Base register for call. */
1916 if (args
.k
== VCALL
) {
1917 ins
= BCINS_ABC(BC_CALLM
, base
, 2, args
.u
.s
.aux
- base
- 1);
1919 if (args
.k
!= VVOID
)
1920 expr_tonextreg(fs
, &args
);
1921 ins
= BCINS_ABC(BC_CALL
, base
, 2, fs
->freereg
- base
);
1923 expr_init(e
, VCALL
, bcemit_INS(fs
, ins
));
1925 fs
->bcbase
[fs
->pc
- 1].line
= line
;
1926 fs
->freereg
= base
+1; /* Leave one result by default. */
1929 /* Parse primary expression. */
1930 static void expr_primary(LexState
*ls
, ExpDesc
*v
)
1932 FuncState
*fs
= ls
->fs
;
1933 /* Parse prefix expression. */
1934 if (ls
->tok
== '(') {
1935 BCLine line
= ls
->linenumber
;
1938 lex_match(ls
, ')', '(', line
);
1939 expr_discharge(ls
->fs
, v
);
1940 } else if (ls
->tok
== TK_name
|| (!LJ_52
&& ls
->tok
== TK_goto
)) {
1943 err_syntax(ls
, LJ_ERR_XSYMBOL
);
1945 for (;;) { /* Parse multiple expression suffixes. */
1946 if (ls
->tok
== '.') {
1948 } else if (ls
->tok
== '[') {
1950 expr_toanyreg(fs
, v
);
1951 expr_bracket(ls
, &key
);
1952 expr_index(fs
, v
, &key
);
1953 } else if (ls
->tok
== ':') {
1957 bcemit_method(fs
, v
, &key
);
1959 } else if (ls
->tok
== '(' || ls
->tok
== TK_string
|| ls
->tok
== '{') {
1960 expr_tonextreg(fs
, v
);
1968 /* Parse simple expression. */
1969 static void expr_simple(LexState
*ls
, ExpDesc
*v
)
1973 expr_init(v
, (LJ_HASFFI
&& tviscdata(&ls
->tokval
)) ? VKCDATA
: VKNUM
, 0);
1974 copyTV(ls
->L
, &v
->u
.nval
, &ls
->tokval
);
1977 expr_init(v
, VKSTR
, 0);
1978 v
->u
.sval
= strV(&ls
->tokval
);
1981 expr_init(v
, VKNIL
, 0);
1984 expr_init(v
, VKTRUE
, 0);
1987 expr_init(v
, VKFALSE
, 0);
1989 case TK_dots
: { /* Vararg. */
1990 FuncState
*fs
= ls
->fs
;
1992 checkcond(ls
, fs
->flags
& PROTO_VARARG
, LJ_ERR_XDOTS
);
1993 bcreg_reserve(fs
, 1);
1994 base
= fs
->freereg
-1;
1995 expr_init(v
, VCALL
, bcemit_ABC(fs
, BC_VARG
, base
, 2, fs
->numparams
));
1999 case '{': /* Table constructor. */
2004 parse_body(ls
, v
, 0, ls
->linenumber
);
2007 expr_primary(ls
, v
);
2013 /* Manage syntactic levels to avoid blowing up the stack. */
2014 static void synlevel_begin(LexState
*ls
)
2016 if (++ls
->level
>= LJ_MAX_XLEVEL
)
2017 lj_lex_error(ls
, 0, LJ_ERR_XLEVELS
);
2020 #define synlevel_end(ls) ((ls)->level--)
2022 /* Convert token to binary operator. */
2023 static BinOpr
token2binop(LexToken tok
)
2026 case '+': return OPR_ADD
;
2027 case '-': return OPR_SUB
;
2028 case '*': return OPR_MUL
;
2029 case '/': return OPR_DIV
;
2030 case '%': return OPR_MOD
;
2031 case '^': return OPR_POW
;
2032 case TK_concat
: return OPR_CONCAT
;
2033 case TK_ne
: return OPR_NE
;
2034 case TK_eq
: return OPR_EQ
;
2035 case '<': return OPR_LT
;
2036 case TK_le
: return OPR_LE
;
2037 case '>': return OPR_GT
;
2038 case TK_ge
: return OPR_GE
;
2039 case TK_and
: return OPR_AND
;
2040 case TK_or
: return OPR_OR
;
2041 default: return OPR_NOBINOPR
;
2045 /* Priorities for each binary operator. ORDER OPR. */
2046 static const struct {
2047 uint8_t left
; /* Left priority. */
2048 uint8_t right
; /* Right priority. */
2050 {6,6}, {6,6}, {7,7}, {7,7}, {7,7}, /* ADD SUB MUL DIV MOD */
2051 {10,9}, {5,4}, /* POW CONCAT (right associative) */
2052 {3,3}, {3,3}, /* EQ NE */
2053 {3,3}, {3,3}, {3,3}, {3,3}, /* LT GE GT LE */
2054 {2,2}, {1,1} /* AND OR */
2057 #define UNARY_PRIORITY 8 /* Priority for unary operators. */
2059 /* Forward declaration. */
2060 static BinOpr
expr_binop(LexState
*ls
, ExpDesc
*v
, uint32_t limit
);
2062 /* Parse unary expression. */
2063 static void expr_unop(LexState
*ls
, ExpDesc
*v
)
2066 if (ls
->tok
== TK_not
) {
2068 } else if (ls
->tok
== '-') {
2070 } else if (ls
->tok
== '#') {
2077 expr_binop(ls
, v
, UNARY_PRIORITY
);
2078 bcemit_unop(ls
->fs
, op
, v
);
2081 /* Parse binary expressions with priority higher than the limit. */
2082 static BinOpr
expr_binop(LexState
*ls
, ExpDesc
*v
, uint32_t limit
)
2087 op
= token2binop(ls
->tok
);
2088 while (op
!= OPR_NOBINOPR
&& priority
[op
].left
> limit
) {
2092 bcemit_binop_left(ls
->fs
, op
, v
);
2093 /* Parse binary expression with higher priority. */
2094 nextop
= expr_binop(ls
, &v2
, priority
[op
].right
);
2095 bcemit_binop(ls
->fs
, op
, v
, &v2
);
2099 return op
; /* Return unconsumed binary operator (if any). */
2102 /* Parse expression. */
2103 static void expr(LexState
*ls
, ExpDesc
*v
)
2105 expr_binop(ls
, v
, 0); /* Priority 0: parse whole expression. */
2108 /* Assign expression to the next register. */
2109 static void expr_next(LexState
*ls
)
2113 expr_tonextreg(ls
->fs
, &e
);
2116 /* Parse conditional expression. */
2117 static BCPos
expr_cond(LexState
*ls
)
2121 if (v
.k
== VKNIL
) v
.k
= VKFALSE
;
2122 bcemit_branch_t(ls
->fs
, &v
);
2126 /* -- Assignments --------------------------------------------------------- */
2128 /* List of LHS variables. */
2129 typedef struct LHSVarList
{
2130 ExpDesc v
; /* LHS variable. */
2131 struct LHSVarList
*prev
; /* Link to previous LHS variable. */
2134 /* Eliminate write-after-read hazards for local variable assignment. */
2135 static void assign_hazard(LexState
*ls
, LHSVarList
*lh
, const ExpDesc
*v
)
2137 FuncState
*fs
= ls
->fs
;
2138 BCReg reg
= v
->u
.s
.info
; /* Check against this variable. */
2139 BCReg tmp
= fs
->freereg
; /* Rename to this temp. register (if needed). */
2141 for (; lh
; lh
= lh
->prev
) {
2142 if (lh
->v
.k
== VINDEXED
) {
2143 if (lh
->v
.u
.s
.info
== reg
) { /* t[i], t = 1, 2 */
2145 lh
->v
.u
.s
.info
= tmp
;
2147 if (lh
->v
.u
.s
.aux
== reg
) { /* t[i], i = 1, 2 */
2149 lh
->v
.u
.s
.aux
= tmp
;
2154 bcemit_AD(fs
, BC_MOV
, tmp
, reg
); /* Rename conflicting variable. */
2155 bcreg_reserve(fs
, 1);
2159 /* Adjust LHS/RHS of an assignment. */
2160 static void assign_adjust(LexState
*ls
, BCReg nvars
, BCReg nexps
, ExpDesc
*e
)
2162 FuncState
*fs
= ls
->fs
;
2163 int32_t extra
= (int32_t)nvars
- (int32_t)nexps
;
2164 if (e
->k
== VCALL
) {
2165 extra
++; /* Compensate for the VCALL itself. */
2166 if (extra
< 0) extra
= 0;
2167 setbc_b(bcptr(fs
, e
), extra
+1); /* Fixup call results. */
2168 if (extra
> 1) bcreg_reserve(fs
, (BCReg
)extra
-1);
2171 expr_tonextreg(fs
, e
); /* Close last expression. */
2172 if (extra
> 0) { /* Leftover LHS are set to nil. */
2173 BCReg reg
= fs
->freereg
;
2174 bcreg_reserve(fs
, (BCReg
)extra
);
2175 bcemit_nil(fs
, reg
, (BCReg
)extra
);
2180 /* Recursively parse assignment statement. */
2181 static void parse_assignment(LexState
*ls
, LHSVarList
*lh
, BCReg nvars
)
2184 checkcond(ls
, VLOCAL
<= lh
->v
.k
&& lh
->v
.k
<= VINDEXED
, LJ_ERR_XSYNTAX
);
2185 if (lex_opt(ls
, ',')) { /* Collect LHS list and recurse upwards. */
2188 expr_primary(ls
, &vl
.v
);
2189 if (vl
.v
.k
== VLOCAL
)
2190 assign_hazard(ls
, lh
, &vl
.v
);
2191 checklimit(ls
->fs
, ls
->level
+ nvars
, LJ_MAX_XLEVEL
, "variable names");
2192 parse_assignment(ls
, &vl
, nvars
+1);
2193 } else { /* Parse RHS. */
2196 nexps
= expr_list(ls
, &e
);
2197 if (nexps
== nvars
) {
2199 if (bc_op(*bcptr(ls
->fs
, &e
)) == BC_VARG
) { /* Vararg assignment. */
2202 } else { /* Multiple call results. */
2203 e
.u
.s
.info
= e
.u
.s
.aux
; /* Base of call is not relocatable. */
2207 bcemit_store(ls
->fs
, &lh
->v
, &e
);
2210 assign_adjust(ls
, nvars
, nexps
, &e
);
2212 ls
->fs
->freereg
-= nexps
- nvars
; /* Drop leftover regs. */
2214 /* Assign RHS to LHS and recurse downwards. */
2215 expr_init(&e
, VNONRELOC
, ls
->fs
->freereg
-1);
2216 bcemit_store(ls
->fs
, &lh
->v
, &e
);
2219 /* Parse call statement or assignment. */
2220 static void parse_call_assign(LexState
*ls
)
2222 FuncState
*fs
= ls
->fs
;
2224 expr_primary(ls
, &vl
.v
);
2225 if (vl
.v
.k
== VCALL
) { /* Function call statement. */
2226 setbc_b(bcptr(fs
, &vl
.v
), 1); /* No results. */
2227 } else { /* Start of an assignment. */
2229 parse_assignment(ls
, &vl
, 1);
2233 /* Parse 'local' statement. */
2234 static void parse_local(LexState
*ls
)
2236 if (lex_opt(ls
, TK_function
)) { /* Local function declaration. */
2238 FuncState
*fs
= ls
->fs
;
2239 var_new(ls
, 0, lex_str(ls
));
2240 expr_init(&v
, VLOCAL
, fs
->freereg
);
2241 v
.u
.s
.aux
= fs
->varmap
[fs
->freereg
];
2242 bcreg_reserve(fs
, 1);
2244 parse_body(ls
, &b
, 0, ls
->linenumber
);
2245 /* bcemit_store(fs, &v, &b) without setting VSTACK_VAR_RW. */
2247 expr_toreg(fs
, &b
, v
.u
.s
.info
);
2248 /* The upvalue is in scope, but the local is only valid after the store. */
2249 var_get(ls
, fs
, fs
->nactvar
- 1).startpc
= fs
->pc
;
2250 } else { /* Local variable declaration. */
2252 BCReg nexps
, nvars
= 0;
2253 do { /* Collect LHS. */
2254 var_new(ls
, nvars
++, lex_str(ls
));
2255 } while (lex_opt(ls
, ','));
2256 if (lex_opt(ls
, '=')) { /* Optional RHS. */
2257 nexps
= expr_list(ls
, &e
);
2258 } else { /* Or implicitly set to nil. */
2262 assign_adjust(ls
, nvars
, nexps
, &e
);
2267 /* Parse 'function' statement. */
2268 static void parse_func(LexState
*ls
, BCLine line
)
2273 lj_lex_next(ls
); /* Skip 'function'. */
2274 /* Parse function name. */
2276 while (ls
->tok
== '.') /* Multiple dot-separated fields. */
2278 if (ls
->tok
== ':') { /* Optional colon to signify method call. */
2282 parse_body(ls
, &b
, needself
, line
);
2284 bcemit_store(fs
, &v
, &b
);
2285 fs
->bcbase
[fs
->pc
- 1].line
= line
; /* Set line for the store. */
2288 /* -- Control transfer statements ----------------------------------------- */
2290 /* Check for end of block. */
2291 static int parse_isend(LexToken tok
)
2294 case TK_else
: case TK_elseif
: case TK_end
: case TK_until
: case TK_eof
:
2301 /* Parse 'return' statement. */
2302 static void parse_return(LexState
*ls
)
2305 FuncState
*fs
= ls
->fs
;
2306 lj_lex_next(ls
); /* Skip 'return'. */
2307 fs
->flags
|= PROTO_HAS_RETURN
;
2308 if (parse_isend(ls
->tok
) || ls
->tok
== ';') { /* Bare return. */
2309 ins
= BCINS_AD(BC_RET0
, 0, 1);
2310 } else { /* Return with one or more values. */
2311 ExpDesc e
; /* Receives the _last_ expression in the list. */
2312 BCReg nret
= expr_list(ls
, &e
);
2313 if (nret
== 1) { /* Return one result. */
2314 if (e
.k
== VCALL
) { /* Check for tail call. */
2315 BCIns
*ip
= bcptr(fs
, &e
);
2316 /* It doesn't pay off to add BC_VARGT just for 'return ...'. */
2317 if (bc_op(*ip
) == BC_VARG
) goto notailcall
;
2319 ins
= BCINS_AD(bc_op(*ip
)-BC_CALL
+BC_CALLT
, bc_a(*ip
), bc_c(*ip
));
2320 } else { /* Can return the result from any register. */
2321 ins
= BCINS_AD(BC_RET1
, expr_toanyreg(fs
, &e
), 2);
2324 if (e
.k
== VCALL
) { /* Append all results from a call. */
2326 setbc_b(bcptr(fs
, &e
), 0);
2327 ins
= BCINS_AD(BC_RETM
, fs
->nactvar
, e
.u
.s
.aux
- fs
->nactvar
);
2329 expr_tonextreg(fs
, &e
); /* Force contiguous registers. */
2330 ins
= BCINS_AD(BC_RET
, fs
->nactvar
, nret
+1);
2334 if (fs
->flags
& PROTO_CHILD
)
2335 bcemit_AJ(fs
, BC_UCLO
, 0, 0); /* May need to close upvalues first. */
2336 bcemit_INS(fs
, ins
);
2339 /* Parse 'break' statement. */
2340 static void parse_break(LexState
*ls
)
2342 ls
->fs
->bl
->flags
|= FSCOPE_BREAK
;
2343 gola_new(ls
, NAME_BREAK
, VSTACK_GOTO
, bcemit_jmp(ls
->fs
));
2346 /* Parse 'goto' statement. */
2347 static void parse_goto(LexState
*ls
)
2349 FuncState
*fs
= ls
->fs
;
2350 GCstr
*name
= lex_str(ls
);
2351 VarInfo
*vl
= gola_findlabel(ls
, name
);
2352 if (vl
) /* Treat backwards goto within same scope like a loop. */
2353 bcemit_AJ(fs
, BC_LOOP
, vl
->slot
, -1); /* No BC range check. */
2354 fs
->bl
->flags
|= FSCOPE_GOLA
;
2355 gola_new(ls
, name
, VSTACK_GOTO
, bcemit_jmp(fs
));
2359 static void parse_label(LexState
*ls
)
2361 FuncState
*fs
= ls
->fs
;
2364 fs
->lasttarget
= fs
->pc
;
2365 fs
->bl
->flags
|= FSCOPE_GOLA
;
2366 lj_lex_next(ls
); /* Skip '::'. */
2368 if (gola_findlabel(ls
, name
))
2369 lj_lex_error(ls
, 0, LJ_ERR_XLDUP
, strdata(name
));
2370 idx
= gola_new(ls
, name
, VSTACK_LABEL
, fs
->pc
);
2371 lex_check(ls
, TK_label
);
2372 /* Recursively parse trailing statements: labels and ';' (Lua 5.2 only). */
2374 if (ls
->tok
== TK_label
) {
2378 } else if (LJ_52
&& ls
->tok
== ';') {
2384 /* Trailing label is considered to be outside of scope. */
2385 if (parse_isend(ls
->tok
) && ls
->tok
!= TK_until
)
2386 ls
->vstack
[idx
].slot
= fs
->bl
->nactvar
;
2387 gola_resolve(ls
, fs
->bl
, idx
);
2390 /* -- Blocks, loops and conditional statements ---------------------------- */
2392 /* Parse a block. */
2393 static void parse_block(LexState
*ls
)
2395 FuncState
*fs
= ls
->fs
;
2397 fscope_begin(fs
, &bl
, 0);
2402 /* Parse 'while' statement. */
2403 static void parse_while(LexState
*ls
, BCLine line
)
2405 FuncState
*fs
= ls
->fs
;
2406 BCPos start
, loop
, condexit
;
2408 lj_lex_next(ls
); /* Skip 'while'. */
2409 start
= fs
->lasttarget
= fs
->pc
;
2410 condexit
= expr_cond(ls
);
2411 fscope_begin(fs
, &bl
, FSCOPE_LOOP
);
2412 lex_check(ls
, TK_do
);
2413 loop
= bcemit_AD(fs
, BC_LOOP
, fs
->nactvar
, 0);
2415 jmp_patch(fs
, bcemit_jmp(fs
), start
);
2416 lex_match(ls
, TK_end
, TK_while
, line
);
2418 jmp_tohere(fs
, condexit
);
2419 jmp_patchins(fs
, loop
, fs
->pc
);
2422 /* Parse 'repeat' statement. */
2423 static void parse_repeat(LexState
*ls
, BCLine line
)
2425 FuncState
*fs
= ls
->fs
;
2426 BCPos loop
= fs
->lasttarget
= fs
->pc
;
2429 fscope_begin(fs
, &bl1
, FSCOPE_LOOP
); /* Breakable loop scope. */
2430 fscope_begin(fs
, &bl2
, 0); /* Inner scope. */
2431 lj_lex_next(ls
); /* Skip 'repeat'. */
2432 bcemit_AD(fs
, BC_LOOP
, fs
->nactvar
, 0);
2434 lex_match(ls
, TK_until
, TK_repeat
, line
);
2435 condexit
= expr_cond(ls
); /* Parse condition (still inside inner scope). */
2436 if (!(bl2
.flags
& FSCOPE_UPVAL
)) { /* No upvalues? Just end inner scope. */
2438 } else { /* Otherwise generate: cond: UCLO+JMP out, !cond: UCLO+JMP loop. */
2439 parse_break(ls
); /* Break from loop and close upvalues. */
2440 jmp_tohere(fs
, condexit
);
2441 fscope_end(fs
); /* End inner scope and close upvalues. */
2442 condexit
= bcemit_jmp(fs
);
2444 jmp_patch(fs
, condexit
, loop
); /* Jump backwards if !cond. */
2445 jmp_patchins(fs
, loop
, fs
->pc
);
2446 fscope_end(fs
); /* End loop scope. */
2449 /* Parse numeric 'for'. */
2450 static void parse_for_num(LexState
*ls
, GCstr
*varname
, BCLine line
)
2452 FuncState
*fs
= ls
->fs
;
2453 BCReg base
= fs
->freereg
;
2455 BCPos loop
, loopend
;
2456 /* Hidden control variables. */
2457 var_new_fixed(ls
, FORL_IDX
, VARNAME_FOR_IDX
);
2458 var_new_fixed(ls
, FORL_STOP
, VARNAME_FOR_STOP
);
2459 var_new_fixed(ls
, FORL_STEP
, VARNAME_FOR_STEP
);
2460 /* Visible copy of index variable. */
2461 var_new(ls
, FORL_EXT
, varname
);
2466 if (lex_opt(ls
, ',')) {
2469 bcemit_AD(fs
, BC_KSHORT
, fs
->freereg
, 1); /* Default step is 1. */
2470 bcreg_reserve(fs
, 1);
2472 var_add(ls
, 3); /* Hidden control variables. */
2473 lex_check(ls
, TK_do
);
2474 loop
= bcemit_AJ(fs
, BC_FORI
, base
, NO_JMP
);
2475 fscope_begin(fs
, &bl
, 0); /* Scope for visible variables. */
2477 bcreg_reserve(fs
, 1);
2480 /* Perform loop inversion. Loop control instructions are at the end. */
2481 loopend
= bcemit_AJ(fs
, BC_FORL
, base
, NO_JMP
);
2482 fs
->bcbase
[loopend
].line
= line
; /* Fix line for control ins. */
2483 jmp_patchins(fs
, loopend
, loop
+1);
2484 jmp_patchins(fs
, loop
, fs
->pc
);
2487 /* Try to predict whether the iterator is next() and specialize the bytecode.
2488 ** Detecting next() and pairs() by name is simplistic, but quite effective.
2489 ** The interpreter backs off if the check for the closure fails at runtime.
2491 static int predict_next(LexState
*ls
, FuncState
*fs
, BCPos pc
)
2493 BCIns ins
= fs
->bcbase
[pc
].ins
;
2496 switch (bc_op(ins
)) {
2498 name
= gco2str(gcref(var_get(ls
, fs
, bc_d(ins
)).name
));
2501 name
= gco2str(gcref(ls
->vstack
[fs
->uvmap
[bc_d(ins
)]].name
));
2504 /* There's no inverse index (yet), so lookup the strings. */
2505 o
= lj_tab_getstr(fs
->kt
, lj_str_newlit(ls
->L
, "pairs"));
2506 if (o
&& tvhaskslot(o
) && tvkslot(o
) == bc_d(ins
))
2508 o
= lj_tab_getstr(fs
->kt
, lj_str_newlit(ls
->L
, "next"));
2509 if (o
&& tvhaskslot(o
) && tvkslot(o
) == bc_d(ins
))
2515 return (name
->len
== 5 && !strcmp(strdata(name
), "pairs")) ||
2516 (name
->len
== 4 && !strcmp(strdata(name
), "next"));
2519 /* Parse 'for' iterator. */
2520 static void parse_for_iter(LexState
*ls
, GCstr
*indexname
)
2522 FuncState
*fs
= ls
->fs
;
2526 BCReg base
= fs
->freereg
+ 3;
2527 BCPos loop
, loopend
, exprpc
= fs
->pc
;
2530 /* Hidden control variables. */
2531 var_new_fixed(ls
, nvars
++, VARNAME_FOR_GEN
);
2532 var_new_fixed(ls
, nvars
++, VARNAME_FOR_STATE
);
2533 var_new_fixed(ls
, nvars
++, VARNAME_FOR_CTL
);
2534 /* Visible variables returned from iterator. */
2535 var_new(ls
, nvars
++, indexname
);
2536 while (lex_opt(ls
, ','))
2537 var_new(ls
, nvars
++, lex_str(ls
));
2538 lex_check(ls
, TK_in
);
2539 line
= ls
->linenumber
;
2540 assign_adjust(ls
, 3, expr_list(ls
, &e
), &e
);
2541 bcreg_bump(fs
, 3); /* The iterator needs another 3 slots (func + 2 args). */
2542 isnext
= (nvars
<= 5 && predict_next(ls
, fs
, exprpc
));
2543 var_add(ls
, 3); /* Hidden control variables. */
2544 lex_check(ls
, TK_do
);
2545 loop
= bcemit_AJ(fs
, isnext
? BC_ISNEXT
: BC_JMP
, base
, NO_JMP
);
2546 fscope_begin(fs
, &bl
, 0); /* Scope for visible variables. */
2547 var_add(ls
, nvars
-3);
2548 bcreg_reserve(fs
, nvars
-3);
2551 /* Perform loop inversion. Loop control instructions are at the end. */
2552 jmp_patchins(fs
, loop
, fs
->pc
);
2553 bcemit_ABC(fs
, isnext
? BC_ITERN
: BC_ITERC
, base
, nvars
-3+1, 2+1);
2554 loopend
= bcemit_AJ(fs
, BC_ITERL
, base
, NO_JMP
);
2555 fs
->bcbase
[loopend
-1].line
= line
; /* Fix line for control ins. */
2556 fs
->bcbase
[loopend
].line
= line
;
2557 jmp_patchins(fs
, loopend
, loop
+1);
2560 /* Parse 'for' statement. */
2561 static void parse_for(LexState
*ls
, BCLine line
)
2563 FuncState
*fs
= ls
->fs
;
2566 fscope_begin(fs
, &bl
, FSCOPE_LOOP
);
2567 lj_lex_next(ls
); /* Skip 'for'. */
2568 varname
= lex_str(ls
); /* Get first variable name. */
2570 parse_for_num(ls
, varname
, line
);
2571 else if (ls
->tok
== ',' || ls
->tok
== TK_in
)
2572 parse_for_iter(ls
, varname
);
2574 err_syntax(ls
, LJ_ERR_XFOR
);
2575 lex_match(ls
, TK_end
, TK_for
, line
);
2576 fscope_end(fs
); /* Resolve break list. */
2579 /* Parse condition and 'then' block. */
2580 static BCPos
parse_then(LexState
*ls
)
2583 lj_lex_next(ls
); /* Skip 'if' or 'elseif'. */
2584 condexit
= expr_cond(ls
);
2585 lex_check(ls
, TK_then
);
2590 /* Parse 'if' statement. */
2591 static void parse_if(LexState
*ls
, BCLine line
)
2593 FuncState
*fs
= ls
->fs
;
2595 BCPos escapelist
= NO_JMP
;
2596 flist
= parse_then(ls
);
2597 while (ls
->tok
== TK_elseif
) { /* Parse multiple 'elseif' blocks. */
2598 jmp_append(fs
, &escapelist
, bcemit_jmp(fs
));
2599 jmp_tohere(fs
, flist
);
2600 flist
= parse_then(ls
);
2602 if (ls
->tok
== TK_else
) { /* Parse optional 'else' block. */
2603 jmp_append(fs
, &escapelist
, bcemit_jmp(fs
));
2604 jmp_tohere(fs
, flist
);
2605 lj_lex_next(ls
); /* Skip 'else'. */
2608 jmp_append(fs
, &escapelist
, flist
);
2610 jmp_tohere(fs
, escapelist
);
2611 lex_match(ls
, TK_end
, TK_if
, line
);
2614 /* -- Parse statements ---------------------------------------------------- */
2616 /* Parse a statement. Returns 1 if it must be the last one in a chunk. */
2617 static int parse_stmt(LexState
*ls
)
2619 BCLine line
= ls
->linenumber
;
2625 parse_while(ls
, line
);
2630 lex_match(ls
, TK_end
, TK_do
, line
);
2633 parse_for(ls
, line
);
2636 parse_repeat(ls
, line
);
2639 parse_func(ls
, line
);
2647 return 1; /* Must be last. */
2651 return !LJ_52
; /* Must be last in Lua 5.1. */
2661 if (LJ_52
|| lj_lex_lookahead(ls
) == TK_name
) {
2665 } /* else: fallthrough */
2667 parse_call_assign(ls
);
2673 /* A chunk is a list of statements optionally separated by semicolons. */
2674 static void parse_chunk(LexState
*ls
)
2678 while (!islast
&& !parse_isend(ls
->tok
)) {
2679 islast
= parse_stmt(ls
);
2681 lua_assert(ls
->fs
->framesize
>= ls
->fs
->freereg
&&
2682 ls
->fs
->freereg
>= ls
->fs
->nactvar
);
2683 ls
->fs
->freereg
= ls
->fs
->nactvar
; /* Free registers after each stmt. */
2688 /* Entry point of bytecode parser. */
2689 GCproto
*lj_parse(LexState
*ls
)
2694 lua_State
*L
= ls
->L
;
2695 #ifdef LUAJIT_DISABLE_DEBUGINFO
2696 ls
->chunkname
= lj_str_newlit(L
, "=");
2698 ls
->chunkname
= lj_str_newz(L
, ls
->chunkarg
);
2700 setstrV(L
, L
->top
, ls
->chunkname
); /* Anchor chunkname string. */
2708 fs
.flags
|= PROTO_VARARG
; /* Main chunk is always a vararg func. */
2709 fscope_begin(&fs
, &bl
, 0);
2710 bcemit_AD(&fs
, BC_FUNCV
, 0, 0); /* Placeholder. */
2711 lj_lex_next(ls
); /* Read-ahead first token. */
2713 if (ls
->tok
!= TK_eof
)
2714 err_token(ls
, TK_eof
);
2715 pt
= fs_finish(ls
, ls
->linenumber
);
2716 L
->top
--; /* Drop chunkname. */
2717 lua_assert(fs
.prev
== NULL
);
2718 lua_assert(ls
->fs
== NULL
);
2719 lua_assert(pt
->sizeuv
== 0);