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);
luaK_patchtohere(fs, bl1.continuelist);
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 */
}
void luaK_tostack (LexState *ls, expdesc *v, int onlyone) {
FuncState *fs = ls->fs;
if (!discharge(fs, v)) { /* `v' is an expression? */
OpCode previous = GET_OPCODE(fs->f->code[fs->pc-1]);
if (!ISJUMP(previous) && v->u.l.f == NO_JUMP && v->u.l.t == NO_JUMP) {
/* expression has no jumps */
if (onlyone)
luaK_setcallreturns(fs, 1); /* call must return 1 value */
}
else { /* expression has jumps */
int final; /* position after whole expression */
int j = NO_JUMP; /* eventual jump over values */
int p_nil = NO_JUMP; /* position of an eventual PUSHNIL */
int p_1 = NO_JUMP; /* position of an eventual PUSHINT */
if (ISJUMP(previous) || need_value(fs, v->u.l.f, OP_JMPONF)
|| need_value(fs, v->u.l.t, OP_JMPONT)) {
/* expression needs values */
if (ISJUMP(previous))
luaK_concat(fs, &v->u.l.t, fs->pc-1); /* put `previous' in t. list */
else {
j = code_label(fs, OP_JMP, NO_JUMP); /* to jump over both pushes */
/* correct stack for compiler and symbolic execution */
luaK_adjuststack(fs, 1);
}
p_nil = code_label(fs, OP_PUSHNILJMP, 0);
p_1 = code_label(fs, OP_PUSHINT, 1);
luaK_patchlist(fs, j, luaK_getlabel(fs));
}
final = luaK_getlabel(fs);
luaK_patchlistaux(fs, v->u.l.f, p_nil, OP_JMPONF, final);
luaK_patchlistaux(fs, v->u.l.t, p_1, OP_JMPONT, final);
v->u.l.f = v->u.l.t = NO_JUMP;
}
static void luaK_testgo (FuncState *fs, expdesc *v, int invert, OpCode jump) {
int prevpos; /* position of last instruction */
Instruction *previous;
int *golist, *exitlist;
if (!invert) {
golist = &v->u.l.f; /* go if false */
exitlist = &v->u.l.t; /* exit if true */
}
else {
golist = &v->u.l.t; /* go if true */
exitlist = &v->u.l.f; /* exit if false */
}
discharge1(fs, v);
prevpos = fs->pc-1;
previous = &fs->f->code[prevpos];
LUA_ASSERT(*previous==previous_instruction(fs), "no jump allowed here");
if (!ISJUMP(GET_OPCODE(*previous)))
prevpos = luaK_code1(fs, jump, NO_JUMP);
else { /* last instruction is already a jump */
if (invert)
SET_OPCODE(*previous, invertjump(GET_OPCODE(*previous)));
}
luaK_concat(fs, exitlist, prevpos); /* insert last jump in `exitlist' */
luaK_patchlist(fs, *golist, luaK_getlabel(fs));
*golist = NO_JUMP;
}
static void forbody (LexState *ls, int base, int line, int nvars, int isnum)
{
/* forbody -> DO block */
BlockCnt bl;
FuncState *fs = GetCurrentFuncState( ls );
adjustlocalvars(ls, 3); /* control variables */
checknext(ls, TK_DO);
int 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);
int 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 closegoto(LexState *ls, int g, Labeldesc *label)
{
int i;
FuncState *fs = ls->fs;
Labellist *gl = &ls->dyd->gt;
Labeldesc *gt = &gl->arr[g];
lua_assert(luaS_eqstr(gt->name, label->name));
if (gt->nactvar < label->nactvar)
{
TString *vname = getlocvar(fs, gt->nactvar)->varname;
const char *msg = luaO_pushfstring(ls->L,
"<goto %s> at line %d jumps into the scope of local " LUA_QS,
getstr(gt->name), gt->line, getstr(vname));
semerror(ls, msg);
}
luaK_patchlist(fs, gt->pc, label->pc);
/* remove goto from pending list */
for (i = g; i < gl->n - 1; i++)
gl->arr[i] = gl->arr[i + 1];
gl->n--;
}
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);
luaK_patchlist(fs, bl.continuelist, whileinit); /* continue goes to start, too */
check_match(ls, TK_END, TK_WHILE, line);
leaveblock(fs);
luaK_patchtohere(fs, condexit); /* false conditions finish the loop */
}
/*
** returns current `pc' and marks it as a jump target (to avoid wrong
** optimizations with consecutive instructions not in the same basic block).
** discharge list of jumps to last target.
*/
int luaK_getlabel (FuncState *fs) {
if (fs->pc != fs->lasttarget) {
int lasttarget = fs->lasttarget;
fs->lasttarget = fs->pc;
luaK_patchlist(fs, fs->jlt, lasttarget); /* discharge old list `jlt' */
fs->jlt = NO_JUMP; /* nobody jumps to this new label (yet) */
}
return fs->pc;
}
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);
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 *pbl = (BlockCnt*)malloc(sizeof(BlockCnt));
luaX_next(ls); /* skip WHILE */
whileinit = luaK_getlabel(fs);
condexit = cond(ls);
enterblock(fs, pbl, 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 */
free(pbl);
}
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 */
}