"use strict";
const assert = require('assert');
const defs = require('./defs.js');
const llex = require('./llex.js');
const lobject = require('./lobject.js');
const lopcodes = require('./lopcodes.js');
const lparser = require('./lparser.js');
const lstring = require('./lstring.js');
const ltable = require('./ltable.js');
const ltm = require('./ltm.js');
const lvm = require('./lvm.js');
const CT = defs.CT;
const OpCodesI = lopcodes.OpCodesI;
const TValue = lobject.TValue;
/* Maximum number of registers in a Lua function (must fit in 8 bits) */
const MAXREGS = 255;
/*
** Marks the end of a patch list. It is an invalid value both as an absolute
** address, and as a list link (would link an element to itself).
*/
const NO_JUMP = -1;
const BinOpr = {
OPR_ADD: 0,
OPR_SUB: 1,
OPR_MUL: 2,
OPR_MOD: 3,
OPR_POW: 4,
OPR_DIV: 5,
OPR_IDIV: 6,
OPR_BAND: 7,
OPR_BOR: 8,
OPR_BXOR: 9,
OPR_SHL: 10,
OPR_SHR: 11,
OPR_CONCAT: 12,
OPR_EQ: 13,
OPR_LT: 14,
OPR_LE: 15,
OPR_NE: 16,
OPR_GT: 17,
OPR_GE: 18,
OPR_AND: 19,
OPR_OR: 20,
OPR_NOBINOPR: 21
};
const UnOpr = {
OPR_MINUS: 0,
OPR_BNOT: 1,
OPR_NOT: 2,
OPR_LEN: 3,
OPR_NOUNOPR: 4
};
const hasjumps = function(e) {
return e.t !== e.f;
};
/*
** If expression is a numeric constant, fills 'v' with its value
** and returns true. Otherwise, returns false.
*/
const tonumeral = function(e, v) {
let ek = lparser.expkind;
if (hasjumps(e))
return false; /* not a numeral */
switch (e.k) {
case ek.VKINT:
if (v) {
v.type = CT.LUA_TNUMINT;
v.value = e.u.ival;
}
return true;
case ek.VKFLT:
if (v) {
v.type = CT.LUA_TNUMFLT;
v.value = e.u.nval;
}
return true;
default: return false;
}
};
/*
** Create a OP_LOADNIL instruction, but try to optimize: if the previous
** instruction is also OP_LOADNIL and ranges are compatible, adjust
** range of previous instruction instead of emitting a new one. (For
** instance, 'local a; local b' will generate a single opcode.)
*/
const luaK_nil = function(fs, from, n) {
let previous;
let l = from + n - 1; /* last register to set nil */
if (fs.pc > fs.lasttarget) { /* no jumps to current position? */
previous = fs.f.code[fs.pc-1];
if (previous.opcode === OpCodesI.OP_LOADNIL) { /* previous is LOADNIL? */
let pfrom = previous.A; /* get previous range */
let pl = pfrom + previous.B;
if ((pfrom <= from && from <= pl + 1) ||
(from <= pfrom && pfrom <= l + 1)) { /* can connect both? */
if (pfrom < from) from = pfrom; /* from = min(from, pfrom) */
if (pl > l) l = pl; /* l = max(l, pl) */
lopcodes.SETARG_A(previous, from);
lopcodes.SETARG_B(previous, l - from);
return;
}
} /* else go through */
}
luaK_codeABC(fs, OpCodesI.OP_LOADNIL, from, n - 1, 0); /* else no optimization */
};
const getinstruction = function(fs, e) {
return fs.f.code[e.u.info];
};
/*
** Gets the destination address of a jump instruction. Used to traverse
** a list of jumps.
*/
const getjump = function(fs, pc) {
let offset = fs.f.code[pc].sBx;
if (offset === NO_JUMP) /* point to itself represents end of list */
return NO_JUMP; /* end of list */
else
return pc + 1 + offset; /* turn offset into absolute position */
};
/*
** Fix jump instruction at position 'pc' to jump to 'dest'.
** (Jump addresses are relative in Lua)
*/
const fixjump = function(fs, pc, dest) {
let jmp = fs.f.code[pc];
let offset = dest - (pc + 1);
assert(dest !== NO_JUMP);
if (Math.abs(offset) > lopcodes.MAXARG_sBx)
llex.luaX_syntaxerror(fs.ls, defs.to_luastring("control structure too long", true));
lopcodes.SETARG_sBx(jmp, offset);
};
/*
** Concatenate jump-list 'l2' into jump-list 'l1'
*/
const luaK_concat = function(fs, l1, l2) {
if (l2 === NO_JUMP) return l1; /* nothing to concatenate? */
else if (l1 === NO_JUMP) /* no original list? */
l1 = l2;
else {
let list = l1;
let next = getjump(fs, list);
while (next !== NO_JUMP) { /* find last element */
list = next;
next = getjump(fs, list);
}
fixjump(fs, list, l2);
}
return l1;
};
/*
** Create a jump instruction and return its position, so its destination
** can be fixed later (with 'fixjump'). If there are jumps to
** this position (kept in 'jpc'), link them all together so that
** 'patchlistaux' will fix all them directly to the final destination.
*/
const luaK_jump = function (fs) {
let jpc = fs.jpc; /* save list of jumps to here */
fs.jpc = NO_JUMP; /* no more jumps to here */
let j = luaK_codeAsBx(fs, OpCodesI.OP_JMP, 0, NO_JUMP);
j = luaK_concat(fs, j, jpc); /* keep them on hold */
return j;
};
const luaK_jumpto = function(fs, t) {
return luaK_patchlist(fs, luaK_jump(fs), t);
};
/*
** Code a 'return' instruction
*/
const luaK_ret = function(fs, first, nret) {
luaK_codeABC(fs, OpCodesI.OP_RETURN, first, nret + 1, 0);
};
/*
** Code a "conditional jump", that is, a test or comparison opcode
** followed by a jump. Return jump position.
*/
const condjump = function(fs, op, A, B, C) {
luaK_codeABC(fs, op, A, B, C);
return luaK_jump(fs);
};
/*
** returns current 'pc' and marks it as a jump target (to avoid wrong
** optimizations with consecutive instructions not in the same basic block).
*/
const luaK_getlabel = function(fs) {
fs.lasttarget = fs.pc;
return fs.pc;
};
/*
** Returns the position of the instruction "controlling" a given
** jump (that is, its condition), or the jump itself if it is
** unconditional.
*/
const getjumpcontrol = function(fs, pc) {
if (pc >= 1 && lopcodes.testTMode(fs.f.code[pc - 1].opcode))
return fs.f.code[pc - 1];
else
return fs.f.code[pc];
};
/*
** Patch destination register for a TESTSET instruction.
** If instruction in position 'node' is not a TESTSET, return 0 ("fails").
** Otherwise, if 'reg' is not 'NO_REG', set it as the destination
** register. Otherwise, change instruction to a simple 'TEST' (produces
** no register value)
*/
const patchtestreg = function(fs, node, reg) {
let i = getjumpcontrol(fs, node);
if (i.opcode !== OpCodesI.OP_TESTSET)
return false; /* cannot patch other instructions */
if (reg !== lopcodes.NO_REG && reg !== i.B)
lopcodes.SETARG_A(i, reg);
else {
/* no register to put value or register already has the value;
change instruction to simple test */
i = lopcodes.CREATE_ABC(OpCodesI.OP_TEST, i.B, 0, i.C);
}
return true;
};
/*
** Traverse a list of tests ensuring no one produces a value
*/
const removevalues = function(fs, list) {
for (; list !== NO_JUMP; list = getjump(fs, list))
patchtestreg(fs, list, lopcodes.NO_REG);
};
/*
** Traverse a list of tests, patching their destination address and
** registers: tests producing values jump to 'vtarget' (and put their
** values in 'reg'), other tests jump to 'dtarget'.
*/
const patchlistaux = function(fs, list, vtarget, reg, dtarget) {
while (list !== NO_JUMP) {
let next = getjump(fs, list);
if (patchtestreg(fs, list, reg))
fixjump(fs, list, vtarget);
else
fixjump(fs, list, dtarget); /* jump to default target */
list = next;
}
};
/*
** Ensure all pending jumps to current position are fixed (jumping
** to current position with no values) and reset list of pending
** jumps
*/
const dischargejpc = function(fs) {
patchlistaux(fs, fs.jpc, fs.pc, lopcodes.NO_REG, fs.pc);
fs.jpc = NO_JUMP;
};
/*
** Add elements in 'list' to list of pending jumps to "here"
** (current position)
*/
const luaK_patchtohere = function(fs, list) {
luaK_getlabel(fs); /* mark "here" as a jump target */
fs.jpc = luaK_concat(fs, fs.jpc, list);
};
/*
** Path all jumps in 'list' to jump to 'target'.
** (The assert means that we cannot fix a jump to a forward address
** because we only know addresses once code is generated.)
*/
const luaK_patchlist = function(fs, list, target) {
if (target === fs.pc) /* 'target' is current position? */
luaK_patchtohere(fs, list); /* add list to pending jumps */
else {
assert(target < fs.pc);
patchlistaux(fs, list, target, lopcodes.NO_REG, target);
}
};
/*
** Path all jumps in 'list' to close upvalues up to given 'level'
** (The assertion checks that jumps either were closing nothing
** or were closing higher levels, from inner blocks.)
*/
const luaK_patchclose = function(fs, list, level) {
level++; /* argument is +1 to reserve 0 as non-op */
for (; list !== NO_JUMP; list = getjump(fs, list)) {
let ins = fs.f.code[list];
assert(ins.opcode === OpCodesI.OP_JMP && (ins.A === 0 || ins.A >= level));
lopcodes.SETARG_A(ins, level);
}
};
/*
** Emit instruction 'i', checking for array sizes and saving also its
** line information. Return 'i' position.
*/
const luaK_code = function(fs, i) {
let f = fs.f;
dischargejpc(fs); /* 'pc' will change */
/* put new instruction in code array */
f.code[fs.pc] = i;
f.lineinfo[fs.pc] = fs.ls.lastline;
return fs.pc++;
};
/*
** Format and emit an 'iABC' instruction. (Assertions check consistency
** of parameters versus opcode.)
*/
const luaK_codeABC = function(fs, o, a, b, c) {
assert(lopcodes.getOpMode(o) === lopcodes.iABC);
assert(lopcodes.getBMode(o) !== lopcodes.OpArgN || b === 0);
assert(lopcodes.getCMode(o) !== lopcodes.OpArgN || c === 0);
assert(a <= lopcodes.MAXARG_A && b <= lopcodes.MAXARG_B && c <= lopcodes.MAXARG_C);
return luaK_code(fs, lopcodes.CREATE_ABC(o, a, b, c));
};
/*
** Format and emit an 'iABx' instruction.
*/
const luaK_codeABx = function(fs, o, a, bc) {
assert(lopcodes.getOpMode(o) === lopcodes.iABx || lopcodes.getOpMode(o) === lopcodes.iAsBx);
assert(lopcodes.getCMode(o) === lopcodes.OpArgN);
assert(a <= lopcodes.MAXARG_A && bc <= lopcodes.MAXARG_Bx);
return luaK_code(fs, lopcodes.CREATE_ABx(o, a, bc));
};
const luaK_codeAsBx = function(fs,o,A,sBx) {
return luaK_codeABx(fs, o, A, (sBx) + lopcodes.MAXARG_sBx);
};
/*
** Emit an "extra argument" instruction (format 'iAx')
*/
const codeextraarg = function(fs, a) {
assert(a <= lopcodes.MAXARG_Ax);
return luaK_code(fs, lopcodes.CREATE_Ax(OpCodesI.OP_EXTRAARG, a));
};
/*
** Emit a "load constant" instruction, using either 'OP_LOADK'
** (if constant index 'k' fits in 18 bits) or an 'OP_LOADKX'
** instruction with "extra argument".
*/
const luaK_codek = function(fs, reg, k) {
if (k <= lopcodes.MAXARG_Bx)
return luaK_codeABx(fs, OpCodesI.OP_LOADK, reg, k);
else {
let p = luaK_codeABx(fs, OpCodesI.OP_LOADKX, reg, 0);
codeextraarg(fs, k);
return p;
}
};
/*
** Check register-stack level, keeping track of its maximum size
** in field 'maxstacksize'
*/
const luaK_checkstack = function(fs, n) {
let newstack = fs.freereg + n;
if (newstack > fs.f.maxstacksize) {
if (newstack >= MAXREGS)
llex.luaX_syntaxerror(fs.ls, defs.to_luastring("function or expression needs too many registers", true));
fs.f.maxstacksize = newstack;
}
};
/*
** Reserve 'n' registers in register stack
*/
const luaK_reserveregs = function(fs, n) {
luaK_checkstack(fs, n);
fs.freereg += n;
};
/*
** Free register 'reg', if it is neither a constant index nor
** a local variable.
*/
const freereg = function(fs, reg) {
if (!lopcodes.ISK(reg) && reg >= fs.nactvar) {
fs.freereg--;
assert(reg === fs.freereg);
}
};
/*
** Free register used by expression 'e' (if any)
*/
const freeexp = function(fs, e) {
if (e.k === lparser.expkind.VNONRELOC)
freereg(fs, e.u.info);
};
/*
** Free registers used by expressions 'e1' and 'e2' (if any) in proper
** order.
*/
const freeexps = function(fs, e1, e2) {
let r1 = (e1.k === lparser.expkind.VNONRELOC) ? e1.u.info : -1;
let r2 = (e2.k === lparser.expkind.VNONRELOC) ? e2.u.info : -1;
if (r1 > r2) {
freereg(fs, r1);
freereg(fs, r2);
}
else {
freereg(fs, r2);
freereg(fs, r1);
}
};
/*
** Add constant 'v' to prototype's list of constants (field 'k').
** Use scanner's table to cache position of constants in constant list
** and try to reuse constants. Because some values should not be used
** as keys (nil cannot be a key, integer keys can collapse with float
** keys), the caller must provide a useful 'key' for indexing the cache.
*/
const addk = function(fs, key, v) {
let f = fs.f;
let idx = ltable.luaH_set(fs.ls.h, key); /* index scanner table */
if (idx.ttisinteger()) { /* is there an index there? */
let k = idx.value;
/* correct value? (warning: must distinguish floats from integers!) */
if (k < fs.nk && f.k[k].ttype() === v.ttype() && f.k[k].value === v.value)
return k; /* reuse index */
}
/* constant not found; create a new entry */
let k = fs.nk;
idx.setivalue(k);
f.k[k] = v;
fs.nk++;
return k;
};
/*
** Add a string to list of constants and return its index.
*/
const luaK_stringK = function(fs, s) {
let o = new TValue(CT.LUA_TLNGSTR, s);
return addk(fs, o, o); /* use string itself as key */
};
/*
** Add an integer to list of constants and return its index.
** Integers use userdata as keys to avoid collision with floats with
** same value; conversion to 'void*' is used only for hashing, so there
** are no "precision" problems.
*/
const luaK_intK = function(fs, n) {
/* FIXME: shouldn't use string as key. need to use pointer */
let k = new TValue(CT.LUA_TLNGSTR, lstring.luaS_bless(fs.L, defs.to_luastring(`${n}`)));
let o = new TValue(CT.LUA_TNUMINT, n);
return addk(fs, k, o);
};
/*
** Add a float to list of constants and return its index.
*/
const luaK_numberK = function(fs, r) {
let o = new TValue(CT.LUA_TNUMFLT, r);
return addk(fs, o, o); /* use number itself as key */
};
/*
** Add a boolean to list of constants and return its index.
*/
const boolK = function(fs, b) {
let o = new TValue(CT.LUA_TBOOLEAN, b);
return addk(fs, o, o); /* use boolean itself as key */
};
/*
** Add nil to list of constants and return its index.
*/
const nilK = function(fs) {
let v = new TValue(CT.LUA_TNIL, null);
let k = new TValue(CT.LUA_TTABLE, fs.ls.h);
/* cannot use nil as key; instead use table itself to represent nil */
return addk(fs, k, v);
};
/*
** Fix an expression to return the number of results 'nresults'.
** Either 'e' is a multi-ret expression (function call or vararg)
** or 'nresults' is LUA_MULTRET (as any expression can satisfy that).
*/
const luaK_setreturns = function(fs, e, nresults) {
let ek = lparser.expkind;
if (e.k === ek.VCALL) { /* expression is an open function call? */
lopcodes.SETARG_C(getinstruction(fs, e), nresults + 1);
}
else if (e.k === ek.VVARARG) {
let pc = getinstruction(fs, e);
lopcodes.SETARG_B(pc, nresults + 1);
lopcodes.SETARG_A(pc, fs.freereg);
luaK_reserveregs(fs, 1);
}
else assert(nresults === defs.LUA_MULTRET);
};
const luaK_setmultret = function(fs, e) {
luaK_setreturns(fs, e, defs.LUA_MULTRET);
};
/*
** Fix an expression to return one result.
** If expression is not a multi-ret expression (function call or
** vararg), it already returns one result, so nothing needs to be done.
** Function calls become VNONRELOC expressions (as its result comes
** fixed in the base register of the call), while vararg expressions
** become VRELOCABLE (as OP_VARARG puts its results where it wants).
** (Calls are created returning one result, so that does not need
** to be fixed.)
*/
const luaK_setoneret = function(fs, e) {
let ek = lparser.expkind;
if (e.k === ek.VCALL) { /* expression is an open function call? */
/* already returns 1 value */
assert(getinstruction(fs, e).C === 2);
e.k = ek.VNONRELOC; /* result has fixed position */
e.u.info = getinstruction(fs, e).A;
} else if (e.k === ek.VVARARG) {
lopcodes.SETARG_B(getinstruction(fs, e), 2);
e.k = ek.VRELOCABLE; /* can relocate its simple result */
}
};
/*
** Ensure that expression 'e' is not a variable.
*/
const luaK_dischargevars = function(fs, e) {
let ek = lparser.expkind;
switch (e.k) {
case ek.VLOCAL: { /* already in a register */
e.k = ek.VNONRELOC; /* becomes a non-relocatable value */
break;
}
case ek.VUPVAL: { /* move value to some (pending) register */
e.u.info = luaK_codeABC(fs, OpCodesI.OP_GETUPVAL, 0, e.u.info, 0);
e.k = ek.VRELOCABLE;
break;
}
case ek.VINDEXED: {
let op;
freereg(fs, e.u.ind.idx);
if (e.u.ind.vt === ek.VLOCAL) { /* is 't' in a register? */
freereg(fs, e.u.ind.t);
op = OpCodesI.OP_GETTABLE;
} else {
assert(e.u.ind.vt === ek.VUPVAL);
op = OpCodesI.OP_GETTABUP; /* 't' is in an upvalue */
}
e.u.info = luaK_codeABC(fs, op, 0, e.u.ind.t, e.u.ind.idx);
e.k = ek.VRELOCABLE;
break;
}
case ek.VVARARG: case ek.VCALL: {
luaK_setoneret(fs, e);
break;
}
default: break; /* there is one value available (somewhere) */
}
};
const code_loadbool = function(fs, A, b, jump) {
luaK_getlabel(fs); /* those instructions may be jump targets */
return luaK_codeABC(fs, OpCodesI.OP_LOADBOOL, A, b, jump);
};
/*
** Ensures expression value is in register 'reg' (and therefore
** 'e' will become a non-relocatable expression).
*/
const discharge2reg = function(fs, e, reg) {
let ek = lparser.expkind;
luaK_dischargevars(fs, e);
switch (e.k) {
case ek.VNIL: {
luaK_nil(fs, reg, 1);
break;
}
case ek.VFALSE: case ek.VTRUE: {
luaK_codeABC(fs, OpCodesI.OP_LOADBOOL, reg, e.k === ek.VTRUE, 0);
break;
}
case ek.VK: {
luaK_codek(fs, reg, e.u.info);
break;
}
case ek.VKFLT: {
luaK_codek(fs, reg, luaK_numberK(fs, e.u.nval));
break;
}
case ek.VKINT: {
luaK_codek(fs, reg, luaK_intK(fs, e.u.ival));
break;
}
case ek.VRELOCABLE: {
let pc = getinstruction(fs, e);
lopcodes.SETARG_A(pc, reg); /* instruction will put result in 'reg' */
break;
}
case ek.VNONRELOC: {
if (reg !== e.u.info)
luaK_codeABC(fs, OpCodesI.OP_MOVE, reg, e.u.info, 0);
break;
}
default: {
assert(e.k === ek.VJMP);
return; /* nothing to do... */
}
}
e.u.info = reg;
e.k = ek.VNONRELOC;
};
/*
** Ensures expression value is in any register.
*/
const discharge2anyreg = function(fs, e) {
if (e.k !== lparser.expkind.VNONRELOC) { /* no fixed register yet? */
luaK_reserveregs(fs, 1); /* get a register */
discharge2reg(fs, e, fs.freereg-1); /* put value there */
}
};
/*
** check whether list has any jump that do not produce a value
** or produce an inverted value
*/
const need_value = function(fs, list) {
for (; list !== NO_JUMP; list = getjump(fs, list)) {
let i = getjumpcontrol(fs, list);
if (i.opcode !== OpCodesI.OP_TESTSET) return true;
}
return false; /* not found */
};
/*
** 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).
*/
const exp2reg = function(fs, e, reg) {
let ek = lparser.expkind;
discharge2reg(fs, e, reg);
if (e.k === ek.VJMP) /* expression itself is a test? */
e.t = luaK_concat(fs, e.t, e.u.info); /* put this jump in 't' list */
if (hasjumps(e)) {
let final; /* position after whole expression */
let p_f = NO_JUMP; /* position of an eventual LOAD false */
let p_t = NO_JUMP; /* position of an eventual LOAD true */
if (need_value(fs, e.t) || need_value(fs, e.f)) {
let fj = (e.k === ek.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);
}
e.f = e.t = NO_JUMP;
e.u.info = reg;
e.k = ek.VNONRELOC;
};
/*
** Ensures final expression result (including results from its jump
** lists) is in next available register.
*/
const luaK_exp2nextreg = function(fs, e) {
luaK_dischargevars(fs, e);
freeexp(fs, e);
luaK_reserveregs(fs, 1);
exp2reg(fs, e, fs.freereg - 1);
};
/*
** Ensures final expression result (including results from its jump
** lists) is in some (any) register and return that register.
*/
const luaK_exp2anyreg = function(fs, e) {
luaK_dischargevars(fs, e);
if (e.k === lparser.expkind.VNONRELOC) { /* expression already has a register? */
if (!hasjumps(e)) /* no jumps? */
return e.u.info; /* result is already in a register */
if (e.u.info >= fs.nactvar) { /* reg. is not a local? */
exp2reg(fs, e, e.u.info); /* put final result in it */
return e.u.info;
}
}
luaK_exp2nextreg(fs, e); /* otherwise, use next available register */
return e.u.info;
};
/*
** Ensures final expression result is either in a register or in an
** upvalue.
*/
const luaK_exp2anyregup = function(fs, e) {
if (e.k !== lparser.expkind.VUPVAL || hasjumps(e))
luaK_exp2anyreg(fs, e);
};
/*
** Ensures final expression result is either in a register or it is
** a constant.
*/
const luaK_exp2val = function(fs, e) {
if (hasjumps(e))
luaK_exp2anyreg(fs, e);
else
luaK_dischargevars(fs, e);
};
/*
** Ensures final expression result is in a valid R/K index
** (that is, it is either in a register or in 'k' with an index
** in the range of R/K indices).
** Returns R/K index.
*/
const luaK_exp2RK = function(fs, e) {
let ek = lparser.expkind;
let vk = false;
luaK_exp2val(fs, e);
switch (e.k) { /* move constants to 'k' */
case ek.VTRUE: e.u.info = boolK(fs, true); vk = true; break;
case ek.VFALSE: e.u.info = boolK(fs, false); vk = true; break;
case ek.VNIL: e.u.info = nilK(fs); vk = true; break;
case ek.VKINT: e.u.info = luaK_intK(fs, e.u.ival); vk = true; break;
case ek.VKFLT: e.u.info = luaK_numberK(fs, e.u.nval); vk = true; break;
case ek.VK: vk = true; break;
default: break;
}
if (vk) {
e.k = ek.VK;
if (e.u.info <= lopcodes.MAXINDEXRK) /* constant fits in 'argC'? */
return lopcodes.RKASK(e.u.info);
}
/* not a constant in the right range: put it in a register */
return luaK_exp2anyreg(fs, e);
};
/*
** Generate code to store result of expression 'ex' into variable 'var'.
*/
const luaK_storevar = function(fs, vr, ex) {
let ek = lparser.expkind;
switch (vr.k) {
case ek.VLOCAL: {
freeexp(fs, ex);
exp2reg(fs, ex, vr.u.info); /* compute 'ex' into proper place */
return;
}
case ek.VUPVAL: {
let e = luaK_exp2anyreg(fs, ex);
luaK_codeABC(fs, OpCodesI.OP_SETUPVAL, e, vr.u.info, 0);
break;
}
case ek.VINDEXED: {
let op = (vr.u.ind.vt === ek.VLOCAL) ? OpCodesI.OP_SETTABLE : OpCodesI.OP_SETTABUP;
let e = luaK_exp2RK(fs, ex);
luaK_codeABC(fs, op, vr.u.ind.t, vr.u.ind.idx, e);
break;
}
}
freeexp(fs, ex);
};
/*
** Emit SELF instruction (convert expression 'e' into 'e:key(e,').
*/
const luaK_self = function(fs, e, key) {
luaK_exp2anyreg(fs, e);
let ereg = e.u.info; /* register where 'e' was placed */
freeexp(fs, e);
e.u.info = fs.freereg; /* base register for op_self */
e.k = lparser.expkind.VNONRELOC; /* self expression has a fixed register */
luaK_reserveregs(fs, 2); /* function and 'self' produced by op_self */
luaK_codeABC(fs, OpCodesI.OP_SELF, e.u.info, ereg, luaK_exp2RK(fs, key));
freeexp(fs, key);
};
/*
** Negate condition 'e' (where 'e' is a comparison).
*/
const negatecondition = function(fs, e) {
let pc = getjumpcontrol(fs, e.u.info);
assert(lopcodes.testTMode(pc.opcode) && pc.opcode !== OpCodesI.OP_TESTSET && pc.opcode !== OpCodesI.OP_TEST);
lopcodes.SETARG_A(pc, !(pc.A));
};
/*
** Emit instruction to jump if 'e' is 'cond' (that is, if 'cond'
** is true, code will jump if 'e' is true.) Return jump position.
** Optimize when 'e' is 'not' something, inverting the condition
** and removing the 'not'.
*/
const jumponcond = function(fs, e, cond) {
if (e.k === lparser.expkind.VRELOCABLE) {
let ie = getinstruction(fs, e);
if (ie.opcode === OpCodesI.OP_NOT) {
fs.pc--; /* remove previous OP_NOT */
return condjump(fs, OpCodesI.OP_TEST, ie.B, 0, !cond);
}
/* else go through */
}
discharge2anyreg(fs, e);
freeexp(fs, e);
return condjump(fs, OpCodesI.OP_TESTSET, lopcodes.NO_REG, e.u.info, cond);
};
/*
** Emit code to go through if 'e' is true, jump otherwise.
*/
const luaK_goiftrue = function(fs, e) {
let ek = lparser.expkind;
let pc; /* pc of new jump */
luaK_dischargevars(fs, e);
switch (e.k) {
case ek.VJMP: { /* condition? */
negatecondition(fs, e); /* jump when it is false */
pc = e.u.info; /* save jump position */
break;
}
case ek.VK: case ek.VKFLT: case ek.VKINT: case ek.VTRUE: {
pc = NO_JUMP; /* always true; do nothing */
break;
}
default: {
pc = jumponcond(fs, e, 0); /* jump when false */
break;
}
}
e.f = luaK_concat(fs, e.f, pc); /* insert new jump in false list */
luaK_patchtohere(fs, e.t); /* true list jumps to here (to go through) */
e.t = NO_JUMP;
};
/*
** Emit code to go through if 'e' is false, jump otherwise.
*/
const luaK_goiffalse = function(fs, e) {
let ek = lparser.expkind;
let pc; /* pc of new jump */
luaK_dischargevars(fs, e);
switch (e.k) {
case ek.VJMP: {
pc = e.u.info; /* already jump if true */
break;
}
case ek.VNIL: case ek.VFALSE: {
pc = NO_JUMP; /* always false; do nothing */
break;
}
default: {
pc = jumponcond(fs, e, 1); /* jump if true */
break;
}
}
e.t = luaK_concat(fs, e.t, pc); /* insert new jump in 't' list */
luaK_patchtohere(fs, e.f); /* false list jumps to here (to go through) */
e.f = NO_JUMP;
};
/*
** Code 'not e', doing constant folding.
*/
const codenot = function(fs, e) {
let ek = lparser.expkind;
luaK_dischargevars(fs, e);
switch (e.k) {
case ek.VNIL: case ek.VFALSE: {
e.k = ek.VTRUE; /* true === not nil === not false */
break;
}
case ek.VK: case ek.VKFLT: case ek.VKINT: case ek.VTRUE: {
e.k = ek.VFALSE; /* false === not "x" === not 0.5 === not 1 === not true */
break;
}
case ek.VJMP: {
negatecondition(fs, e);
break;
}
case ek.VRELOCABLE:
case ek.VNONRELOC: {
discharge2anyreg(fs, e);
freeexp(fs, e);
e.u.info = luaK_codeABC(fs, OpCodesI.OP_NOT, 0, e.u.info, 0);
e.k = ek.VRELOCABLE;
break;
}
}
/* interchange true and false lists */
{ let temp = e.f; e.f = e.t; e.t = temp; }
removevalues(fs, e.f); /* values are useless when negated */
removevalues(fs, e.t);
};
/*
** Create expression 't[k]'. 't' must have its final result already in a
** register or upvalue.
*/
const luaK_indexed = function(fs, t, k) {
let ek = lparser.expkind;
assert(!hasjumps(t) && (lparser.vkisinreg(t.k) || t.k === ek.VUPVAL));
t.u.ind.t = t.u.info; /* register or upvalue index */
t.u.ind.idx = luaK_exp2RK(fs, k); /* R/K index for key */
t.u.ind.vt = (t.k === ek.VUPVAL) ? ek.VUPVAL : ek.VLOCAL;
t.k = ek.VINDEXED;
};
/*
** Return false if folding can raise an error.
** Bitwise operations need operands convertible to integers; division
** operations cannot have 0 as divisor.
*/
const validop = function(op, v1, v2) {
switch (op) {
case defs.LUA_OPBAND: case defs.LUA_OPBOR: case defs.LUA_OPBXOR:
case defs.LUA_OPSHL: case defs.LUA_OPSHR: case defs.LUA_OPBNOT: { /* conversion errors */
return (lvm.tointeger(v1) && lvm.tointeger(v2));
}
case defs.LUA_OPDIV: case defs.LUA_OPIDIV: case defs.LUA_OPMOD: /* division by 0 */
return (v2.value !== 0);
default: return 1; /* everything else is valid */
}
};
/*
** Try to "constant-fold" an operation; return 1 iff successful.
** (In this case, 'e1' has the final result.)
*/
const constfolding = function(fs, op, e1, e2) {
let ek = lparser.expkind;
let v1 = new TValue();
let v2 = new TValue();
let res = new TValue();
if (!tonumeral(e1, v1) || !tonumeral(e2, v2) || !validop(op, v1, v2))
return 0; /* non-numeric operands or not safe to fold */
lobject.luaO_arith(fs.ls.L, op, v1, v2, res); /* does operation */
if (res.ttisinteger()) {
e1.k = ek.VKINT;
e1.u.ival = res.value;
}
else { /* folds neither NaN nor 0.0 (to avoid problems with -0.0) */
let n = res.value;
if (isNaN(n) || n === 0)
return false;
e1.k = ek.VKFLT;
e1.u.nval = n;
}
return true;
};
/*
** Emit code for unary expressions that "produce values"
** (everything but 'not').
** Expression to produce final result will be encoded in 'e'.
*/
const codeunexpval = function(fs, op, e, line) {
let r = luaK_exp2anyreg(fs, e); /* opcodes operate only on registers */
freeexp(fs, e);
e.u.info = luaK_codeABC(fs, op, 0, r, 0); /* generate opcode */
e.k = lparser.expkind.VRELOCABLE; /* all those operations are relocatable */
luaK_fixline(fs, line);
};
/*
** Emit code for binary expressions that "produce values"
** (everything but logical operators 'and'/'or' and comparison
** operators).
** Expression to produce final result will be encoded in 'e1'.
** Because 'luaK_exp2RK' can free registers, its calls must be
** in "stack order" (that is, first on 'e2', which may have more
** recent registers to be released).
*/
const codebinexpval = function(fs, op, e1, e2, line) {
let rk2 = luaK_exp2RK(fs, e2); /* both operands are "RK" */
let rk1 = luaK_exp2RK(fs, e1);
freeexps(fs, e1, e2);
e1.u.info = luaK_codeABC(fs, op, 0, rk1, rk2); /* generate opcode */
e1.k = lparser.expkind.VRELOCABLE; /* all those operations are relocatable */
luaK_fixline(fs, line);
};
/*
** Emit code for comparisons.
** 'e1' was already put in R/K form by 'luaK_infix'.
*/
const codecomp = function(fs, opr, e1, e2) {
let ek = lparser.expkind;
let rk1;
if (e1.k === ek.VK)
rk1 = lopcodes.RKASK(e1.u.info);
else {
assert(e1.k === ek.VNONRELOC);
rk1 = e1.u.info;
}
let rk2 = luaK_exp2RK(fs, e2);
freeexps(fs, e1, e2);
switch (opr) {
case BinOpr.OPR_NE: { /* '(a ~= b)' ==> 'not (a === b)' */
e1.u.info = condjump(fs, OpCodesI.OP_EQ, 0, rk1, rk2);
break;
}
case BinOpr.OPR_GT: case BinOpr.OPR_GE: {
/* '(a > b)' ==> '(b < a)'; '(a >= b)' ==> '(b <= a)' */
let op = (opr - BinOpr.OPR_NE) + OpCodesI.OP_EQ;
e1.u.info = condjump(fs, op, 1, rk2, rk1); /* invert operands */
break;
}
default: { /* '==', '<', '<=' use their own opcodes */
let op = (opr - BinOpr.OPR_EQ) + OpCodesI.OP_EQ;
e1.u.info = condjump(fs, op, 1, rk1, rk2);
break;
}
}
e1.k = ek.VJMP;
};
/*
** Apply prefix operation 'op' to expression 'e'.
*/
const luaK_prefix = function(fs, op, e, line) {
let ef = new lparser.expdesc();
ef.k = lparser.expkind.VKINT;
ef.u.ival = ef.u.nval = ef.u.info = 0;
ef.t = NO_JUMP;
ef.f = NO_JUMP;
switch (op) {
case UnOpr.OPR_MINUS: case UnOpr.OPR_BNOT: /* use 'ef' as fake 2nd operand */
if (constfolding(fs, op + defs.LUA_OPUNM, e, ef))
break;
/* FALLTHROUGH */
case UnOpr.OPR_LEN:
codeunexpval(fs, op + OpCodesI.OP_UNM, e, line);
break;
case UnOpr.OPR_NOT: codenot(fs, e); break;
}
};
/*
** Process 1st operand 'v' of binary operation 'op' before reading
** 2nd operand.
*/
const luaK_infix = function(fs, op, v) {
switch (op) {
case BinOpr.OPR_AND: {
luaK_goiftrue(fs, v); /* go ahead only if 'v' is true */
break;
}
case BinOpr.OPR_OR: {
luaK_goiffalse(fs, v); /* go ahead only if 'v' is false */
break;
}
case BinOpr.OPR_CONCAT: {
luaK_exp2nextreg(fs, v); /* operand must be on the 'stack' */
break;
}
case BinOpr.OPR_ADD: case BinOpr.OPR_SUB:
case BinOpr.OPR_MUL: case BinOpr.OPR_DIV: case BinOpr.OPR_IDIV:
case BinOpr.OPR_MOD: case BinOpr.OPR_POW:
case BinOpr.OPR_BAND: case BinOpr.OPR_BOR: case BinOpr.OPR_BXOR:
case BinOpr.OPR_SHL: case BinOpr.OPR_SHR: {
if (!tonumeral(v, null))
luaK_exp2RK(fs, v);
/* else keep numeral, which may be folded with 2nd operand */
break;
}
default: {
luaK_exp2RK(fs, v);
break;
}
}
};
/*
** Finalize code for binary operation, after reading 2nd operand.
** For '(a .. b .. c)' (which is '(a .. (b .. c))', because
** concatenation is right associative), merge second CONCAT into first
** one.
*/
const luaK_posfix = function(fs, op, e1, e2, line) {
let ek = lparser.expkind;
switch (op) {
case BinOpr.OPR_AND: {
assert(e1.t === NO_JUMP); /* list closed by 'luK_infix' */
luaK_dischargevars(fs, e2);
e2.f = luaK_concat(fs, e2.f, e1.f);
e1.to(e2);
break;
}
case BinOpr.OPR_OR: {
assert(e1.f === NO_JUMP); /* list closed by 'luK_infix' */
luaK_dischargevars(fs, e2);
e2.t = luaK_concat(fs, e2.t, e1.t);
e1.to(e2);
break;
}
case BinOpr.OPR_CONCAT: {
luaK_exp2val(fs, e2);
let ins = getinstruction(fs, e2);
if (e2.k === ek.VRELOCABLE && ins.opcode === OpCodesI.OP_CONCAT) {
assert(e1.u.info === ins.B - 1);
freeexp(fs, e1);
lopcodes.SETARG_B(ins, e1.u.info);
e1.k = ek.VRELOCABLE; e1.u.info = e2.u.info;
}
else {
luaK_exp2nextreg(fs, e2); /* operand must be on the 'stack' */
codebinexpval(fs, OpCodesI.OP_CONCAT, e1, e2, line);
}
break;
}
case BinOpr.OPR_ADD: case BinOpr.OPR_SUB: case BinOpr.OPR_MUL: case BinOpr.OPR_DIV:
case BinOpr.OPR_IDIV: case BinOpr.OPR_MOD: case BinOpr.OPR_POW:
case BinOpr.OPR_BAND: case BinOpr.OPR_BOR: case BinOpr.OPR_BXOR:
case BinOpr.OPR_SHL: case BinOpr.OPR_SHR: {
if (!constfolding(fs, op + defs.LUA_OPADD, e1, e2))
codebinexpval(fs, op + OpCodesI.OP_ADD, e1, e2, line);
break;
}
case BinOpr.OPR_EQ: case BinOpr.OPR_LT: case BinOpr.OPR_LE:
case BinOpr.OPR_NE: case BinOpr.OPR_GT: case BinOpr.OPR_GE: {
codecomp(fs, op, e1, e2);
break;
}
}
return e1;
};
/*
** Change line information associated with current position.
*/
const luaK_fixline = function(fs, line) {
fs.f.lineinfo[fs.pc - 1] = line;
};
/*
** Emit a SETLIST instruction.
** 'base' is register that keeps table;
** 'nelems' is #table plus those to be stored now;
** 'tostore' is number of values (in registers 'base + 1',...) to add to
** table (or LUA_MULTRET to add up to stack top).
*/
const luaK_setlist = function(fs, base, nelems, tostore) {
let c = (nelems - 1)/lopcodes.LFIELDS_PER_FLUSH + 1;
let b = (tostore === defs.LUA_MULTRET) ? 0 : tostore;
assert(tostore !== 0 && tostore <= lopcodes.LFIELDS_PER_FLUSH);
if (c <= lopcodes.MAXARG_C)
luaK_codeABC(fs, OpCodesI.OP_SETLIST, base, b, c);
else if (c <= lopcodes.MAXARG_Ax) {
luaK_codeABC(fs, OpCodesI.OP_SETLIST, base, b, 0);
codeextraarg(fs, c);
}
else
llex.luaX_syntaxerror(fs.ls, defs.to_luastring("constructor too long", true));
fs.freereg = base + 1; /* free registers with list values */
};
module.exports.BinOpr = BinOpr;
module.exports.NO_JUMP = NO_JUMP;
module.exports.UnOpr = UnOpr;
module.exports.getinstruction = getinstruction;
module.exports.luaK_checkstack = luaK_checkstack;
module.exports.luaK_code = luaK_code;
module.exports.luaK_codeABC = luaK_codeABC;
module.exports.luaK_codeABx = luaK_codeABx;
module.exports.luaK_codeAsBx = luaK_codeAsBx;
module.exports.luaK_codek = luaK_codek;
module.exports.luaK_concat = luaK_concat;
module.exports.luaK_dischargevars = luaK_dischargevars;
module.exports.luaK_exp2RK = luaK_exp2RK;
module.exports.luaK_exp2anyreg = luaK_exp2anyreg;
module.exports.luaK_exp2anyregup = luaK_exp2anyregup;
module.exports.luaK_exp2nextreg = luaK_exp2nextreg;
module.exports.luaK_exp2val = luaK_exp2val;
module.exports.luaK_fixline = luaK_fixline;
module.exports.luaK_getlabel = luaK_getlabel;
module.exports.luaK_goiffalse = luaK_goiffalse;
module.exports.luaK_goiftrue = luaK_goiftrue;
module.exports.luaK_indexed = luaK_indexed;
module.exports.luaK_infix = luaK_infix;
module.exports.luaK_intK = luaK_intK;
module.exports.luaK_jump = luaK_jump;
module.exports.luaK_jumpto = luaK_jumpto;
module.exports.luaK_nil = luaK_nil;
module.exports.luaK_numberK = luaK_numberK;
module.exports.luaK_patchclose = luaK_patchclose;
module.exports.luaK_patchlist = luaK_patchlist;
module.exports.luaK_patchtohere = luaK_patchtohere;
module.exports.luaK_posfix = luaK_posfix;
module.exports.luaK_prefix = luaK_prefix;
module.exports.luaK_reserveregs = luaK_reserveregs;
module.exports.luaK_ret = luaK_ret;
module.exports.luaK_self = luaK_self;
module.exports.luaK_setlist = luaK_setlist;
module.exports.luaK_setmultret = luaK_setmultret;
module.exports.luaK_setoneret = luaK_setoneret;
module.exports.luaK_setreturns = luaK_setreturns;
module.exports.luaK_storevar = luaK_storevar;
module.exports.luaK_stringK = luaK_stringK;