static void leaveblock (FuncState *fs) {
BlockCnt *bl = fs->bl;
fs->bl = bl->previous;
removevars(fs->ls, bl->nactvar);
if (bl->upval)
luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
lua_assert(bl->nactvar == fs->nactvar);
fs->freereg = fs->nactvar; /* free registers */
luaK_patchtohere(fs, bl->breaklist);
}
void luaK_patchlist(FuncState *fs, int list, int target)
{
if (target == fs->pc)
luaK_patchtohere(fs, list);
else
{
lua_assert(target < fs->pc);
patchlistaux(fs, list, target, NO_REG, target);
}
}
static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
/* forbody -> DO block */
BlockCnt bl;
FuncState *fs = ls->fs;
int prep, endfor;
adjustlocalvars(ls, 3); /* control variables */
checknext(ls, TK_DO);
prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs);
enterblock(fs, &bl, 0); /* scope for declared variables */
adjustlocalvars(ls, nvars);
luaK_reserveregs(fs, nvars);
block(ls);
leaveblock(fs); /* end of scope for declared variables */
luaK_patchtohere(fs, prep);
luaK_patchtohere(fs, bl.previous->continuelist); /* continue, if any, jumps to here */
endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) :
luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars);
luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
luaK_patchlist(fs, (isnum ? endfor : luaK_jump(fs)), prep + 1);
}
static void whilestat (LexState *ls, int line) {
/* whilestat -> WHILE cond DO block END */
Instruction codeexp[MAXEXPWHILE + EXTRAEXP];
int lineexp;
int i;
int sizeexp;
FuncState *fs = ls->fs;
int whileinit, blockinit, expinit;
expdesc v;
BlockCnt bl;
next(ls); /* skip WHILE */
whileinit = luaK_jump(fs); /* jump to condition (which will be moved) */
expinit = luaK_getlabel(fs);
expr(ls, &v); /* parse condition */
if (v.k == VK) v.k = VTRUE; /* `trues' are all equal here */
lineexp = ls->linenumber;
luaK_goiffalse(fs, &v);
luaK_concat(fs, &v.f, fs->jpc);
fs->jpc = NO_JUMP;
sizeexp = fs->pc - expinit; /* size of expression code */
if (sizeexp > MAXEXPWHILE)
luaX_syntaxerror(ls, "`while' condition too complex");
for (i = 0; i < sizeexp; i++) /* save `exp' code */
codeexp[i] = fs->f->code[expinit + i];
fs->pc = expinit; /* remove `exp' code */
enterblock(fs, &bl, 1);
check(ls, TK_DO);
blockinit = luaK_getlabel(fs);
block(ls);
luaK_patchtohere(fs, whileinit); /* initial jump jumps to here */
luaK_patchtohere(fs, bl.continuelist);
/* move `exp' back to code */
if (v.t != NO_JUMP) v.t += fs->pc - expinit;
if (v.f != NO_JUMP) v.f += fs->pc - expinit;
for (i=0; i<sizeexp; i++)
luaK_code(fs, codeexp[i], lineexp);
check_match(ls, TK_END, TK_WHILE, line);
leaveblock(fs);
luaK_patchlist(fs, v.t, blockinit); /* true conditions go back to loop */
luaK_patchtohere(fs, v.f); /* false conditions finish the loop */
}
static void leaveblock (FuncState *fs) {
BlockCnt *bl = fs->bl;
fs->bl = bl->previous;
removevars(fs->ls, bl->nactvar);
if (bl->upval)
luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
/* a block either controls scope or breaks (never both) */
lua_assert(!bl->isbreakable || !bl->upval);
lua_assert(bl->nactvar == fs->nactvar);
fs->freereg = fs->nactvar; /* free registers */
luaK_patchtohere(fs, bl->breaklist);
}
static void ifstat (LexState *ls, int line) {
/* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
FuncState *fs = ls->fs;
int flist;
int escapelist = NO_JUMP;
flist = test_then_block(ls); /* IF cond THEN block */
while (ls->t.token == TK_ELSEIF) {
luaK_concat(fs, &escapelist, luaK_jump(fs));
luaK_patchtohere(fs, flist);
flist = test_then_block(ls); /* ELSEIF cond THEN block */
}
if (ls->t.token == TK_ELSE) {
luaK_concat(fs, &escapelist, luaK_jump(fs));
luaK_patchtohere(fs, flist);
luaX_next(ls); /* skip ELSE (after patch, for correct line info) */
block(ls); /* `else' part */
}
else
luaK_concat(fs, &escapelist, flist);
luaK_patchtohere(fs, escapelist);
check_match(ls, TK_END, TK_IF, line);
}
static void repeatstat (LexState *ls, int line) {
/* repeatstat -> REPEAT block UNTIL cond */
int condexit;
FuncState *fs = ls->fs;
int repeat_init = luaK_getlabel(fs);
BlockCnt bl1, bl2;
enterblock(fs, &bl1, 1); /* loop block */
enterblock(fs, &bl2, 0); /* scope block */
luaX_next(ls); /* skip REPEAT */
chunk(ls);
check_match(ls, TK_UNTIL, TK_REPEAT, line);
#if LUA_EXT_CONTINUE
if (bl2.continuelist != NO_JUMP) {
int oldprohibition = fs->prohibitedloc;
luaK_patchtohere(fs, bl2.continuelist);
fs->prohibitedloc = bl2.continuepos;
condexit = cond(ls); /* read condition (inside scope block) */
fs->prohibitedloc = oldprohibition;
bl2.continuelist = NO_JUMP;
}
else {
condexit = cond(ls); /* read condition (inside scope block) */
}
#else
condexit = cond(ls); /* read condition (inside scope block) */
#endif /* LUA_EXT_CONTINUE */
if (!bl2.upval) { /* no upvalues? */
leaveblock(fs); /* finish scope */
luaK_patchlist(ls->fs, condexit, repeat_init); /* close the loop */
}
else { /* complete semantics when there are upvalues */
breakstat(ls); /* if condition then break */
luaK_patchtohere(ls->fs, condexit); /* else... */
leaveblock(fs); /* finish scope... */
luaK_patchlist(ls->fs, luaK_jump(fs), repeat_init); /* and repeat */
}
leaveblock(fs); /* finish loop */
}
static void repeatstat (LexState *ls, int line) {
/* repeatstat -> REPEAT block UNTIL cond */
FuncState *fs = ls->fs;
int repeat_init = luaK_getlabel(fs);
expdesc v;
BlockCnt bl;
enterblock(fs, &bl, 1);
next(ls);
block(ls);
luaK_patchtohere(fs, bl.continuelist);
check_match(ls, TK_UNTIL, TK_REPEAT, line);
cond(ls, &v);
luaK_patchlist(fs, v.f, repeat_init);
leaveblock(fs);
}
static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
BlockCnt bl;
FuncState *fs = ls->fs;
int prep, endfor;
adjustlocalvars(ls, nvars); /* scope for all variables */
check(ls, TK_DO);
enterblock(fs, &bl, 1); /* loop block */
prep = luaK_getlabel(fs);
block(ls);
luaK_patchtohere(fs, prep-1);
endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) :
luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars - 3);
luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
luaK_patchlist(fs, (isnum) ? endfor : luaK_jump(fs), prep);
leaveblock(fs);
}
static void whilestat (LexState *ls, int line) {
/* whilestat -> WHILE cond DO block END */
FuncState *fs = ls->fs;
int whileinit;
int condexit;
BlockCnt bl;
luaX_next(ls); /* skip WHILE */
whileinit = luaK_getlabel(fs);
condexit = cond(ls);
enterblock(fs, &bl, 1);
checknext(ls, TK_DO);
block(ls);
luaK_patchlist(fs, luaK_jump(fs), whileinit);
check_match(ls, TK_END, TK_WHILE, line);
leaveblock(fs);
luaK_patchtohere(fs, condexit); /* false conditions finish the loop */
}
static void casestat (LexState *ls, expdesc *v) {
FuncState *fs = ls->fs;
expdesc v2;
int nargs, base;
/* do not set base to 0 for if case is used in (local) loops, it does not work properly */
base = fs->freereg;
luaK_exp2nextreg(fs, v);
nargs = explist1(ls, &v2); /* put every value into a register */
luaK_exp2nextreg(fs, &v2);
codecompcase(fs, base, nargs+1, v);
fs->freereg -= nargs+1; /* free all registers */
if (v->k == VNIL) v->k = VFALSE;
luaK_goiftrue(fs, v);
luaK_patchtohere(fs, v->t);
checknext(ls, TK_THEN);
block(ls);
}
/*static*/ void FuncState::exp2reg (/*FuncState *fs,*/ expdesc *e, int reg) {
discharge2reg(e, reg);
if (e->k == VJMP)
luaK_concat(&e->t, e->u.info); /* put this jump in 't' list */
if (hasjumps(e)) {
int final; /* position after whole expression */
int p_f = NO_JUMP; /* position of an eventual LOAD false */
int p_t = NO_JUMP; /* position of an eventual LOAD true */
if (need_value(e->t) || need_value(e->f)) {
int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump();
p_f = code_label(reg, 0, 1);
p_t = code_label(reg, 1, 0);
luaK_patchtohere(fj);
}
final = luaK_getlabel();
patchlistaux(e->f, final, reg, p_f);
patchlistaux(e->t, final, reg, p_t);
}
/*
** Ensures final expression result (including results from its jump
** lists) is in register 'reg'.
** If expression has jumps, need to patch these jumps either to
** its final position or to "load" instructions (for those tests
** that do not produce values).
*/
static void exp2reg (FuncState *fs, expdesc *e, int reg) {
discharge2reg(fs, e, reg);
if (e->k == VJMP) /* expression itself is a test? */
luaK_concat(fs, &e->t, e->u.info); /* put this jump in 't' list */
if (hasjumps(e)) {
int final; /* position after whole expression */
int p_f = NO_JUMP; /* position of an eventual LOAD false */
int p_t = NO_JUMP; /* position of an eventual LOAD true */
if (need_value(fs, e->t) || need_value(fs, e->f)) {
int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);
p_f = code_loadbool(fs, reg, 0, 1);
p_t = code_loadbool(fs, reg, 1, 0);
luaK_patchtohere(fs, fj);
}
final = luaK_getlabel(fs);
patchlistaux(fs, e->f, final, reg, p_f);
patchlistaux(fs, e->t, final, reg, p_t);
}
static void exp2reg (FuncState *fs, expdesc *e, int reg) {
discharge2reg(fs, e, reg);
if (e->k == VJMP)
luaK_concat(fs, &e->t, e->u.info); /* put this jump in `t' list */
if (hasjumps(e)) {
if (e->k != VJMP)
luaK_goiftrue(fs, e);
int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);
int p_f = code_label(fs, reg, 0, 1);
luaK_patchtohere(fs, fj);
int p_t = code_label(fs, reg, 1, 0);
patchlistaux(fs, e->f, p_f);
patchlistaux(fs, e->t, p_t);
}
e->f = e->t = NO_JUMP;
e->u.info = reg;
e->k = VNONRELOC;
}
static void leaveblock (FuncState *fs) {
BlockCnt *bl = fs->bl;
LexState *ls = fs->ls;
if (bl->previous && bl->upval) {
/* create a 'jump to here' to close upvalues */
int j = luaK_jump(fs);
luaK_patchclose(fs, j, bl->nactvar);
luaK_patchtohere(fs, j);
}
if (bl->isloop)
breaklabel(ls); /* close pending breaks */
fs->bl = bl->previous;
removevars(fs, bl->nactvar);
lua_assert(bl->nactvar == fs->nactvar);
fs->freereg = fs->nactvar; /* free registers */
ls->dyd->label.n = bl->firstlabel; /* remove local labels */
if (bl->previous) /* inner block? */
movegotosout(fs, bl); /* update pending gotos to outer block */
else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */
undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */
}
void luaK_goiffalse (FuncState *fs, expdesc *e) {
int pc; /* pc of last jump */
luaK_dischargevars(fs, e);
switch (e->k) {
case VJMP: {
pc = e->u.info;
break;
}
case VNIL: case VFALSE: {
pc = NO_JUMP; /* always false; do nothing */
break;
}
default: {
pc = jumponcond(fs, e, 1);
break;
}
}
luaK_concat(fs, &e->t, pc); /* insert last jump in `t' list */
luaK_patchtohere(fs, e->f);
e->f = NO_JUMP;
}
/*static*/ void FuncState::leaveblock (/*FuncState *fs*/) {
//BlockCnt *bl = fs->bl;
//LexState *ls = fs->ls;
if (bl->previous && bl->upval) {
/* create a 'jump to here' to close upvalues */
int j = luaK_jump();
luaK_patchclose(j, bl->nactvar);
luaK_patchtohere(j);
}
if (bl->isloop)
ls->breaklabel(); /* close pending breaks */
bl = bl->previous;
removevars(bl->nactvar);
lua_assert(bl->nactvar == nactvar);
free_reg = nactvar; /* free registers */
ls->dyd->label.n = bl->firstlabel; /* remove local labels */
if (bl->previous) /* inner block? */
movegotosout(bl); /* update pending gotos to outer block */
else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */
ls->undefgoto(&ls->dyd->gt.arr[bl->firstgoto]); /* error */
}
static void leaveblock (FuncState *fs)
{
BlockCnt *bl = (BlockCnt*)fs->blockList.GetFirst();
// Remove the current block from visibility.
fs->blockList.RemoveFirst();
removevars(fs->ls, bl->nactvar);
if ( bl->upval )
{
luaK_codeABC( fs, OP_CLOSE, bl->nactvar, 0, 0 );
}
/* a block either controls scope or breaks (never both) */
lua_assert(!bl->isbreakable || !bl->upval);
lua_assert(bl->nactvar == fs->nactvar);
fs->freereg = fs->nactvar; /* free registers */
luaK_patchtohere(fs, bl->breaklist);
}
void luaK_goiftrue (FuncState *fs, expdesc *e) {
int pc; /* pc of last jump */
luaK_dischargevars(fs, e);
switch (e->k) {
case VJMP: {
invertjump(fs, e);
pc = e->u.info;
break;
}
case VTRUE: {
pc = NO_JUMP; /* always true; do nothing */
break;
}
default: {
pc = jumponcond(fs, e, 0);
break;
}
}
luaK_concat(fs, &e->f, pc); /* insert last jump in `f' list */
luaK_patchtohere(fs, e->t);
e->t = NO_JUMP;
}
static void repeatstat (LexState *ls, int line) {
/* repeatstat -> REPEAT block UNTIL cond */
int condexit;
FuncState *fs = ls->fs;
int repeat_init = luaK_getlabel(fs);
BlockCnt bl1, bl2;
enterblock(fs, &bl1, 1); /* loop block */
enterblock(fs, &bl2, 0); /* scope block */
luaX_next(ls); /* skip REPEAT */
chunk(ls);
check_match(ls, TK_UNTIL, TK_REPEAT, line);
condexit = cond(ls); /* read condition (inside scope block) */
if (!bl2.upval) { /* no upvalues? */
leaveblock(fs); /* finish scope */
luaK_patchlist(ls->fs, condexit, repeat_init); /* close the loop */
}
else { /* complete semantics when there are upvalues */
breakstat(ls); /* if condition then break */
luaK_patchtohere(ls->fs, condexit); /* else... */
leaveblock(fs); /* finish scope... */
luaK_patchlist(ls->fs, luaK_jump(fs), repeat_init); /* and repeat */
}
leaveblock(fs); /* finish loop */
}
static void trystat (LexState *ls, int line) {
/* trystat -> TRY block CATCH err DO block END */
FuncState *fs = ls->fs;
BlockCnt bl;
int base, pc, escapelist = NO_JUMP;
luaX_next(ls);
enterblock(fs, &bl, 2); /* try block */
base = fs->freereg;
new_localvarliteral(ls, "(error obj)", 0);
adjustlocalvars(ls, 1); /* error object */
luaK_reserveregs(fs, 1);
pc = luaK_codeAsBx(fs, OP_TRY, base, NO_JUMP);
chunk(ls);
if (ls->t.token == TK_CATCH) {
TString *varname;
int errobj;
luaK_codeABC(fs, OP_EXITTRY, 0, 0, 0);
luaK_concat(fs, &escapelist, luaK_jump(fs));
SET_OPCODE(fs->f->code[pc], OP_TRYCATCH); /* change it to TRYCATCH */
luaK_patchtohere(fs, pc);
bl.isbreakable = 0;
// local err
luaX_next(ls); /* skip `catch' */
varname = str_checkname(ls); /* first variable name */
// do
checknext(ls, TK_DO);
errobj = fs->freereg;
new_localvar(ls, varname, 0);
adjustlocalvars(ls, 1);
luaK_reserveregs(fs, 1);
luaK_codeABC(fs, OP_MOVE, errobj, base, 0);
block(ls);
} else if (ls->t.token == TK_FINALLY) {
luaK_codeABC(fs, OP_EXITTRY, 0, 0, 0);
luaK_concat(fs, &escapelist, luaK_jump(fs));
SET_OPCODE(fs->f->code[pc], OP_TRYFIN); /* change it to TRYFIN */
luaK_patchtohere(fs, pc);
bl.isbreakable = 3;
luaX_next(ls); /* skip 'finally' */
block(ls);
luaK_codeABC(fs, OP_RETFIN, base, 0, 0); /* OP_ENDFIN jump to the return point */
} else {
luaK_codeABC(fs, OP_EXITTRY, 0, 0, 0);
luaK_concat(fs, &escapelist, pc);
}
leaveblock(fs);
luaK_patchtohere(fs, escapelist);
check_match(ls, TK_END, TK_TRY, line);
}
