static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
expdesc e;
check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
"syntax error");
if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */
struct LHS_assign nv;
nv.prev = lh;
primaryexp(ls, &nv.v);
if (nv.v.k == VLOCAL)
check_conflict(ls, lh, &nv.v);
assignment(ls, &nv, nvars+1);
}
else { /* assignment -> `=' explist1 */
int nexps;
checknext(ls, '=');
nexps = explist1(ls, &e);
if (nexps != nvars) {
adjust_assign(ls, nvars, nexps, &e);
if (nexps > nvars)
ls->fs->freereg -= nexps - nvars; /* remove extra values */
}
else {
luaK_setoneret(ls->fs, &e); /* close last expression */
luaK_storevar(ls->fs, &lh->v, &e);
return; /* avoid default */
}
}
init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
luaK_storevar(ls->fs, &lh->v, &e);
}
static void localstat (LexState *ls)
{
/* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */
int nvars = 0;
int nexps;
expdesc e;
do
{
new_localvar(ls, str_checkname(ls), nvars++);
}
while (testnext(ls, ','));
if (testnext(ls, '='))
{
nexps = explist1(ls, &e);
}
else
{
e.k = VVOID;
nexps = 0;
}
adjust_assign(ls, nvars, nexps, &e);
adjustlocalvars(ls, nvars);
}
static void retstat (LexState *ls) {
/* stat -> RETURN explist */
FuncState *fs = ls->fs;
expdesc e;
int first, nret; /* registers with returned values */
luaX_next(ls); /* skip RETURN */
if (block_follow(ls->t.token) || ls->t.token == ';')
first = nret = 0; /* return no values */
else {
nret = explist1(ls, &e); /* optional return values */
if (hasmultret(e.k)) {
luaK_setmultret(fs, &e);
if (e.k == VCALL && nret == 1) { /* tail call? */
SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
}
first = fs->nactvar;
nret = LUA_MULTRET; /* return all values */
}
else {
if (nret == 1) /* only one single value? */
first = luaK_exp2anyreg(fs, &e);
else {
luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */
first = fs->nactvar; /* return all `active' values */
lua_assert(nret == fs->freereg - first);
}
}
}
luaK_ret(fs, first, nret);
}
static void forlist (LexState *ls, TString *indexname)
{
/* forlist -> NAME {,NAME} IN explist1 forbody */
FuncState *fs = GetCurrentFuncState( ls );
expdesc e;
int nvars = 0;
int base = fs->freereg;
/* create control variables */
new_localvarliteral(ls, "(for generator)", nvars++);
new_localvarliteral(ls, "(for state)", nvars++);
new_localvarliteral(ls, "(for control)", nvars++);
/* create declared variables */
new_localvar(ls, indexname, nvars++);
while (testnext(ls, ','))
{
new_localvar(ls, str_checkname(ls), nvars++);
}
checknext(ls, TK_IN);
int line = ls->linenumber;
adjust_assign(ls, 3, explist1(ls, &e), &e);
luaK_checkstack(fs, 3); /* extra space to call generator */
forbody(ls, base, line, nvars - 3, 0);
}
static void funcargs(LexState* ls, expdesc* f)
{
FuncState* fs = ls->fs;
expdesc args;
int base, nparams;
int line = ls->linenumber;
switch (ls->t.token)
{
case '(': /* funcargs -> `(' [ explist1 ] `)' */
{
if (line != ls->lastline)
luaX_syntaxerror(ls, "ambiguous syntax (function call x new statement)");
luaX_next(ls);
if (ls->t.token == ')') /* arg list is empty? */
args.k = VVOID;
else
{
explist1(ls, &args);
luaK_setmultret(fs, &args);
}
check_match(ls, ')', '(', line);
break;
}
case '{': /* funcargs -> constructor */
{
constructor(ls, &args);
break;
}
case TK_STRING: /* funcargs -> STRING */
{
codestring(ls, &args, ls->t.seminfo.ts);
luaX_next(ls); /* must use `seminfo' before `next' */
break;
}
default:
{
luaX_syntaxerror(ls, "function arguments expected");
return;
}
}
lua_assert(f->k == VNONRELOC);
base = f->u.s.info; /* base register for call */
if (hasmultret(args.k))
nparams = LUA_MULTRET; /* open call */
else
{
if (args.k != VVOID)
luaK_exp2nextreg(fs, &args); /* close last argument */
nparams = fs->freereg - (base + 1);
}
init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams + 1, 2));
luaK_fixline(fs, line);
fs->freereg = base + 1; /* call remove function and arguments and leaves
(unless changed) one result */
}
static int assignment (LexState *ls, struct LHS_assign *lh, int nvars,
lu_byte *from_var)
{
expdesc e;
int from = 0;
check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
"syntax error");
if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */
struct LHS_assign nv;
nv.prev = lh;
primaryexp(ls, &nv.v);
if (nv.v.k == VLOCAL)
check_conflict(ls, lh, &nv.v);
luaY_checklimit(ls->fs, nvars, LUAI_MAXCCALLS - ls->L->nCcalls,
"variables in assignment");
from = assignment(ls, &nv, nvars+1, from_var);
}
else { /* assignment -> IN primaryexp | `=' explist1 */
int nexps;
if (testnext(ls, TK_IN)) {
new_localvarliteral(ls, "(from)", 0);
primaryexp(ls, &e);
luaK_exp2nextreg(ls->fs, &e);
*from_var = ls->fs->nactvar;
adjustlocalvars(ls, 1);
luaK_setoneret(ls->fs, &e); /* close last expression */
getfrom(ls, &e, &lh->v);
luaK_storevar(ls->fs, &lh->v, &e);
return 1; /* avoid default */
}
else {
checknext(ls, '=');
nexps = explist1(ls, &e);
}
if (nexps == nvars) {
luaK_setoneret(ls->fs, &e); /* close last expression */
luaK_storevar(ls->fs, &lh->v, &e);
return 0; /* avoid default */
}
else {
adjust_assign(ls, nvars, nexps, &e);
if (nexps > nvars)
ls->fs->freereg -= nexps - nvars; /* remove extra values */
}
}
init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
if (from) getfrom(ls, &e, &lh->v);
luaK_storevar(ls->fs, &lh->v, &e);
return from;
}
static void retstat (LexState *ls) {
/* stat -> RETURN explist */
FuncState *fs = ls->fs;
BlockCnt *bl = fs->bl;
expdesc e;
int first, nret; /* registers with returned values */
int ret_in_try = 0;
luaX_next(ls); /* skip RETURN */
if (block_follow(ls->t.token) || ls->t.token == ';')
first = nret = 0; /* return no values */
else {
nret = explist1(ls, &e); /* optional return values */
if (hasmultret(e.k)) {
luaK_setmultret(fs, &e);
if (e.k == VCALL && nret == 1) { /* tail call? */
SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
}
first = fs->nactvar;
nret = LUA_MULTRET; /* return all values */
}
else {
if (nret == 1) /* only one single value? */
first = luaK_exp2anyreg(fs, &e);
else {
luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */
first = fs->nactvar; /* return all `active' values */
lua_assert(nret == fs->freereg - first);
}
}
}
/* before return, we should exit all try-catch blocks */
while (bl) {
if (bl->isbreakable == 2) {
if (ret_in_try)
luaK_codeABC(fs, OP_EXITTRY, 0, 0, 0);
else {
ret_in_try = 1;
luaK_codeABC(fs, OP_EXITTRY, first, nret+1, 1); /* here we will save all return values */
}
} else if (bl->isbreakable == 3)
luaX_syntaxerror(ls, "can't return in _finally_ clause");
bl = bl->previous;
}
luaK_codeABC(fs, OP_RETURN, first, nret+1, ret_in_try);
}
static void compound (LexState *ls, struct LHS_assign *lh) {
expdesc rh;
int nexps;
BinOpr op;
check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
"syntax error");
/* parse Compound operation. */
op = getcompopr(ls->t.token);
luaX_next(ls);
/* parse right-hand expression */
nexps = explist1(ls, &rh);
check_condition(ls, nexps == 1, "syntax error");
luaK_posfix(ls->fs, op, &(lh->v), &rh);
}
static void assignment (LexState *ls, struct LHS_assign *lh, int nvars, BinOpr *opr) {
expdesc e;
check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
"syntax error");
if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */
struct LHS_assign nv;
nv.prev = lh;
primaryexp(ls, &nv.v);
if (nv.v.k == VLOCAL)
check_conflict(ls, lh, &nv.v);
assignment(ls, &nv, nvars+1, opr);
}
else { /* assignment -> `=' explist1 */
int nexps;
*opr = OPR_NOBINOPR;
switch(ls->t.token)
{
case '=': break;
case TK_CONCATASSIGN: *opr = OPR_CONCAT; break;
case TK_ADDASSIGN: *opr = OPR_ADD; break;
case TK_SUBASSIGN: *opr = OPR_SUB; break;
case TK_MULASSIGN: *opr = OPR_MUL; break;
case TK_DIVASSIGN: *opr = OPR_DIV; break;
case TK_POWASSIGN: *opr = OPR_POW; break;
case TK_MODASSIGN: *opr = OPR_MOD; break;
default:
luaX_syntaxerror(ls, "unexpected symbol");
break;
};
luaX_next(ls);
nexps = explist1(ls, &e);
if (nexps != nvars) {
adjust_assign(ls, nvars, nexps, &e);
if (nexps > nvars)
ls->fs->freereg -= nexps - nvars; /* remove extra values */
}
else {
luaK_setoneret(ls->fs, &e); /* close last expression */
luaK_storevar(ls->fs, &lh->v, &e, *opr);
return; /* avoid default */
}
}
init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
luaK_storevar(ls->fs, &lh->v, &e, *opr);
}
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 localstat (LexState *ls) {
/* stat -> LOCAL NAME {`,' NAME} [ IN primaryexp | `=' explist1] */
int nvars = 0;
int nexps;
expdesc e;
do {
new_localvar(ls, str_checkname(ls), nvars++);
} while (testnext(ls, ','));
if (testnext(ls, TK_IN)) {
lu_byte from_var;
int regs = ls->fs->freereg;
int vars = ls->fs->nactvar;
luaK_reserveregs(ls->fs, nvars);
adjustlocalvars(ls, nvars);
new_localvarliteral(ls, "(from)", 0);
primaryexp(ls, &e);
luaK_exp2nextreg(ls->fs, &e);
from_var = ls->fs->nactvar;
adjustlocalvars(ls, 1);
luaK_setoneret(ls->fs, &e); /* close last expression */
for (nexps=0; nexps<nvars; nexps++) {
expdesc v, key;
init_exp(&e, VNONRELOC, ls->fs->freereg-1);
codestring(ls, &key, getlocvar(ls->fs, vars+nexps).varname);
luaK_indexed(ls->fs, &e, &key);
init_exp(&v, VLOCAL, regs+nexps);
luaK_storevar(ls->fs, &v, &e);
}
removevars(ls, from_var);
return;
}
if (testnext(ls, '='))
nexps = explist1(ls, &e);
else {
e.k = VVOID;
nexps = 0;
}
adjust_assign(ls, nvars, nexps, &e);
adjustlocalvars(ls, nvars);
}
static void forlist (LexState *ls, TString *indexname) {
/* forlist -> NAME {,NAME} IN explist1 DO body */
FuncState *fs = ls->fs;
expdesc e;
int nvars = 0;
int line;
int base = fs->freereg;
new_localvarstr(ls, "(for generator)", nvars++);
new_localvarstr(ls, "(for state)", nvars++);
new_localvar(ls, indexname, nvars++);
while (testnext(ls, ','))
new_localvar(ls, str_checkname(ls), nvars++);
check(ls, TK_IN);
line = ls->linenumber;
adjust_assign(ls, nvars, explist1(ls, &e), &e);
luaK_checkstack(fs, 3); /* extra space to call generator */
luaK_codeAsBx(fs, OP_TFORPREP, base, NO_JUMP);
forbody(ls, base, line, nvars, 0);
}
static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
expdesc e;
check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
"syntax error");
if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */
struct LHS_assign nv;
nv.prev = lh;
primaryexp(ls, &nv.v);
if (nv.v.k == VLOCAL)
check_conflict(ls, lh, &nv.v);
luaY_checklimit(ls->fs, nvars, LUAI_MAXCCALLS - ls->L->nCcalls,
"variables in assignment");
assignment(ls, &nv, nvars+1);
}
else { /* assignment -> `=' explist1 */
int nexps;
/* hook for inc_assignment */
if(nvars==1) {
switch(ls->t.token) {
case '+': case '-': case '*': case '/': case TK_CONCAT:
inc_assignment(ls,lh);
/* If you're using Shook's table unpack patch, return 0 here.*/
return;
}
}
checknext(ls, '=');
nexps = explist1(ls, &e);
if (nexps != nvars) {
adjust_assign(ls, nvars, nexps, &e);
if (nexps > nvars)
ls->fs->freereg -= nexps - nvars; /* remove extra values */
}
else {
luaK_setoneret(ls->fs, &e); /* close last expression */
luaK_storevar(ls->fs, &lh->v, &e);
return; /* avoid default */
}
}
init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
luaK_storevar(ls->fs, &lh->v, &e);
}
static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
expdesc e;
check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
"syntax error");
if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */
struct LHS_assign nv;
nv.prev = lh;
primaryexp(ls, &nv.v);
if (nv.v.k == VLOCAL)
check_conflict(ls, lh, &nv.v);
luaY_checklimit(ls->fs, nvars, LUAI_MAXCCALLS - ls->L->nCcalls,
"variables in assignment");
assignment(ls, &nv, nvars+1);
}
else { /* assignment -> `=' explist1 */
int nexps;
#if LUA_MUTATION_OPERATORS
luaX_next(ls); /* consume `=' token. */
#else
checknext(ls, '=');
#endif /* LUA_MUTATION_OPERATORS */
nexps = explist1(ls, &e);
if (nexps != nvars) {
adjust_assign(ls, nvars, nexps, &e);
if (nexps > nvars)
ls->fs->freereg -= nexps - nvars; /* remove extra values */
}
else {
luaK_setoneret(ls->fs, &e); /* close last expression */
luaK_storevar(ls->fs, &lh->v, &e);
return; /* avoid default */
}
}
init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
luaK_storevar(ls->fs, &lh->v, &e);
}
