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Luaj 3.0-beta1 for the jse platform
/*******************************************************************************
* Copyright (c) 2009 Luaj.org. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
******************************************************************************/
package org.luaj.vm2.compiler;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.Hashtable;
import org.luaj.vm2.LocVars;
import org.luaj.vm2.Lua;
import org.luaj.vm2.LuaError;
import org.luaj.vm2.LuaInteger;
import org.luaj.vm2.LuaString;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Prototype;
import org.luaj.vm2.compiler.FuncState.BlockCnt;
import org.luaj.vm2.lib.MathLib;
public class LexState {
protected static final String RESERVED_LOCAL_VAR_FOR_CONTROL = "(for control)";
protected static final String RESERVED_LOCAL_VAR_FOR_STATE = "(for state)";
protected static final String RESERVED_LOCAL_VAR_FOR_GENERATOR = "(for generator)";
protected static final String RESERVED_LOCAL_VAR_FOR_STEP = "(for step)";
protected static final String RESERVED_LOCAL_VAR_FOR_LIMIT = "(for limit)";
protected static final String RESERVED_LOCAL_VAR_FOR_INDEX = "(for index)";
// keywords array
protected static final String[] RESERVED_LOCAL_VAR_KEYWORDS = new String[] {
RESERVED_LOCAL_VAR_FOR_CONTROL,
RESERVED_LOCAL_VAR_FOR_GENERATOR,
RESERVED_LOCAL_VAR_FOR_INDEX,
RESERVED_LOCAL_VAR_FOR_LIMIT,
RESERVED_LOCAL_VAR_FOR_STATE,
RESERVED_LOCAL_VAR_FOR_STEP
};
private static final Hashtable RESERVED_LOCAL_VAR_KEYWORDS_TABLE = new Hashtable();
static {
for ( int i=0; i=", "<=", "~=",
"::", "", "", "", "", "",
};
final static int
/* terminal symbols denoted by reserved words */
TK_AND=257, TK_BREAK=258, TK_DO=259, TK_ELSE=260, TK_ELSEIF=261,
TK_END=262, TK_FALSE=263, TK_FOR=264, TK_FUNCTION=265, TK_GOTO=266, TK_IF=267,
TK_IN=268, TK_LOCAL=269, TK_NIL=270, TK_NOT=271, TK_OR=272, TK_REPEAT=273,
TK_RETURN=274, TK_THEN=275, TK_TRUE=276, TK_UNTIL=277, TK_WHILE=278,
/* other terminal symbols */
TK_CONCAT=279, TK_DOTS=280, TK_EQ=281, TK_GE=282, TK_LE=283, TK_NE=284,
TK_DBCOLON=285, TK_EOS=286, TK_NUMBER=287, TK_NAME=288, TK_STRING=289;
final static int FIRST_RESERVED = TK_AND;
final static int NUM_RESERVED = TK_WHILE+1-FIRST_RESERVED;
final static Hashtable RESERVED = new Hashtable();
static {
for ( int i=0; i= '0' && c <= '9')
|| (c >= 'a' && c <= 'z')
|| (c >= 'A' && c <= 'Z')
|| (c == '_');
// return Character.isLetterOrDigit(c);
}
private boolean isalpha(int c) {
return (c >= 'a' && c <= 'z')
|| (c >= 'A' && c <= 'Z');
}
private boolean isdigit(int c) {
return (c >= '0' && c <= '9');
}
private boolean isxdigit(int c) {
return (c >= '0' && c <= '9')
|| (c >= 'a' && c <= 'f')
|| (c >= 'A' && c <= 'F');
}
private boolean isspace(int c) {
return (c <= ' ');
}
public LexState(LuaC state, InputStream stream) {
this.z = stream;
this.buff = new char[32];
this.L = state;
}
void nextChar() {
try {
current = z.read();
} catch ( IOException e ) {
e.printStackTrace();
current = EOZ;
}
}
boolean currIsNewline() {
return current == '\n' || current == '\r';
}
void save_and_next() {
save( current );
nextChar();
}
void save(int c) {
if ( buff == null || nbuff + 1 > buff.length )
buff = LuaC.realloc( buff, nbuff*2+1 );
buff[nbuff++] = (char) c;
}
String token2str( int token ) {
if ( token < FIRST_RESERVED ) {
return iscntrl(token)?
L.pushfstring( "char("+((int)token)+")" ):
L.pushfstring( String.valueOf( (char) token ) );
} else {
return luaX_tokens[token-FIRST_RESERVED];
}
}
private static boolean iscntrl(int token) {
return token < ' ';
}
String txtToken(int token) {
switch ( token ) {
case TK_NAME:
case TK_STRING:
case TK_NUMBER:
return new String( buff, 0, nbuff );
default:
return token2str( token );
}
}
void lexerror( String msg, int token ) {
String cid = Lua.chunkid( source.tojstring() );
L.pushfstring( cid+":"+linenumber+": "+msg );
if ( token != 0 )
L.pushfstring( "syntax error: "+msg+" near "+txtToken(token) );
throw new LuaError(cid+":"+linenumber+": "+msg);
}
void syntaxerror( String msg ) {
lexerror( msg, t.token );
}
// only called by new_localvarliteral() for var names.
LuaString newstring( String s ) {
return L.newTString(s);
}
LuaString newstring( char[] chars, int offset, int len ) {
return L.newTString(new String(chars, offset, len));
}
void inclinenumber() {
int old = current;
LuaC._assert( currIsNewline() );
nextChar(); /* skip '\n' or '\r' */
if ( currIsNewline() && current != old )
nextChar(); /* skip '\n\r' or '\r\n' */
if ( ++linenumber >= MAX_INT )
syntaxerror("chunk has too many lines");
}
void setinput( LuaC L, int firstByte, InputStream z, LuaString source ) {
this.decpoint = '.';
this.L = L;
this.lookahead.token = TK_EOS; /* no look-ahead token */
this.z = z;
this.fs = null;
this.linenumber = 1;
this.lastline = 1;
this.source = source;
this.envn = LuaValue.ENV; /* environment variable name */
this.nbuff = 0; /* initialize buffer */
this.current = firstByte; /* read first char */
this.skipShebang();
}
private void skipShebang() {
if ( current == '#' )
while (!currIsNewline() && current != EOZ)
nextChar();
}
/*
** =======================================================
** LEXICAL ANALYZER
** =======================================================
*/
boolean check_next(String set) {
if (set.indexOf(current) < 0)
return false;
save_and_next();
return true;
}
void buffreplace(char from, char to) {
int n = nbuff;
char[] p = buff;
while ((--n) >= 0)
if (p[n] == from)
p[n] = to;
}
LuaValue strx2number(String str, SemInfo seminfo) {
char[] c = str.toCharArray();
int s = 0;
while ( s < c.length && isspace(c[s]))
++s;
// Check for negative sign
double sgn = 1.0;
if (s < c.length && c[s] == '-') {
sgn = -1.0;
++s;
}
/* Check for "0x" */
if (s + 2 >= c.length )
return LuaValue.ZERO;
if (c[s++] != '0')
return LuaValue.ZERO;
if (c[s] != 'x' && c[s] != 'X')
return LuaValue.ZERO;
++s;
// read integer part.
double m = 0;
int e = 0;
while (s < c.length && isxdigit(c[s]))
m = (m * 16) + hexvalue(c[s++]);
if (s < c.length && c[s] == '.') {
++s; // skip dot
while (s < c.length && isxdigit(c[s])) {
m = (m * 16) + hexvalue(c[s++]);
e -= 4; // Each fractional part shifts right by 2^4
}
}
if (s < c.length && (c[s] == 'p' || c[s] == 'P')) {
++s;
int exp1 = 0;
boolean neg1 = false;
if (s < c.length && c[s] == '-') {
neg1 = true;
++s;
}
while (s < c.length && isdigit(c[s]))
exp1 = exp1 * 10 + c[s++] - '0';
if (neg1)
exp1 = -exp1;
e += exp1;
}
return LuaValue.valueOf(sgn * m * MathLib.dpow_d(2.0, e));
}
boolean str2d(String str, SemInfo seminfo) {
if (str.indexOf('n')>=0 || str.indexOf('N')>=0)
seminfo.r = LuaValue.ZERO;
else if (str.indexOf('x')>=0 || str.indexOf('X')>=0)
seminfo.r = strx2number(str, seminfo);
else
seminfo.r = LuaValue.valueOf(Double.parseDouble(str.trim()));
return true;
}
void read_numeral(SemInfo seminfo) {
String expo = "Ee";
int first = current;
LuaC._assert (isdigit(current));
save_and_next();
if (first == '0' && check_next("Xx"))
expo = "Pp";
while (true) {
if (check_next(expo))
check_next("+-");
if(isxdigit(current) || current == '.')
save_and_next();
else
break;
}
save('\0');
String str = new String(buff, 0, nbuff);
str2d(str, seminfo);
}
int skip_sep() {
int count = 0;
int s = current;
LuaC._assert (s == '[' || s == ']');
save_and_next();
while (current == '=') {
save_and_next();
count++;
}
return (current == s) ? count : (-count) - 1;
}
void read_long_string(SemInfo seminfo, int sep) {
int cont = 0;
save_and_next(); /* skip 2nd `[' */
if (currIsNewline()) /* string starts with a newline? */
inclinenumber(); /* skip it */
for (boolean endloop = false; !endloop;) {
switch (current) {
case EOZ:
lexerror((seminfo != null) ? "unfinished long string"
: "unfinished long comment", TK_EOS);
break; /* to avoid warnings */
case '[': {
if (skip_sep() == sep) {
save_and_next(); /* skip 2nd `[' */
cont++;
if (LUA_COMPAT_LSTR == 1) {
if (sep == 0)
lexerror("nesting of [[...]] is deprecated", '[');
}
}
break;
}
case ']': {
if (skip_sep() == sep) {
save_and_next(); /* skip 2nd `]' */
if (LUA_COMPAT_LSTR == 2) {
cont--;
if (sep == 0 && cont >= 0)
break;
}
endloop = true;
}
break;
}
case '\n':
case '\r': {
save('\n');
inclinenumber();
if (seminfo == null)
nbuff = 0; /* avoid wasting space */
break;
}
default: {
if (seminfo != null)
save_and_next();
else
nextChar();
}
}
}
if (seminfo != null)
seminfo.ts = L.newTString(LuaString.valueOf(buff, 2 + sep, nbuff - 2 * (2 + sep)));
}
int hexvalue(int c) {
return c <= '9'? c - '0': c <= 'F'? c + 10 - 'A': c + 10 - 'a';
}
int readhexaesc() {
nextChar();
int c1 = current;
nextChar();
int c2 = current;
if (!isxdigit(c1) || !isxdigit(c2))
lexerror("hexadecimal digit expected 'x"+((char)c1)+((char)c2), TK_STRING);
return (hexvalue(c1) << 4) + hexvalue(c2);
}
void read_string(int del, SemInfo seminfo) {
save_and_next();
while (current != del) {
switch (current) {
case EOZ:
lexerror("unfinished string", TK_EOS);
continue; /* to avoid warnings */
case '\n':
case '\r':
lexerror("unfinished string", TK_STRING);
continue; /* to avoid warnings */
case '\\': {
int c;
nextChar(); /* do not save the `\' */
switch (current) {
case 'a': /* bell */
c = '\u0007';
break;
case 'b': /* backspace */
c = '\b';
break;
case 'f': /* form feed */
c = '\f';
break;
case 'n': /* newline */
c = '\n';
break;
case 'r': /* carriage return */
c = '\r';
break;
case 't': /* tab */
c = '\t';
break;
case 'v': /* vertical tab */
c = '\u000B';
break;
case 'x':
c = readhexaesc();
break;
case '\n': /* go through */
case '\r':
save('\n');
inclinenumber();
continue;
case EOZ:
continue; /* will raise an error next loop */
case 'z': { /* zap following span of spaces */
nextChar(); /* skip the 'z' */
while (isspace(current)) {
if (currIsNewline()) inclinenumber();
else nextChar();
}
continue;
}
default: {
if (!isdigit(current))
save_and_next(); /* handles \\, \", \', and \? */
else { /* \xxx */
int i = 0;
c = 0;
do {
c = 10 * c + (current - '0');
nextChar();
} while (++i < 3 && isdigit(current));
if (c > UCHAR_MAX)
lexerror("escape sequence too large", TK_STRING);
save(c);
}
continue;
}
}
save(c);
nextChar();
continue;
}
default:
save_and_next();
}
}
save_and_next(); /* skip delimiter */
seminfo.ts = L.newTString(LuaString.valueOf(buff, 1, nbuff-2));
}
int llex(SemInfo seminfo) {
nbuff = 0;
while (true) {
switch (current) {
case '\n':
case '\r': {
inclinenumber();
continue;
}
case '-': {
nextChar();
if (current != '-')
return '-';
/* else is a comment */
nextChar();
if (current == '[') {
int sep = skip_sep();
nbuff = 0; /* `skip_sep' may dirty the buffer */
if (sep >= 0) {
read_long_string(null, sep); /* long comment */
nbuff = 0;
continue;
}
}
/* else short comment */
while (!currIsNewline() && current != EOZ)
nextChar();
continue;
}
case '[': {
int sep = skip_sep();
if (sep >= 0) {
read_long_string(seminfo, sep);
return TK_STRING;
} else if (sep == -1)
return '[';
else
lexerror("invalid long string delimiter", TK_STRING);
}
case '=': {
nextChar();
if (current != '=')
return '=';
else {
nextChar();
return TK_EQ;
}
}
case '<': {
nextChar();
if (current != '=')
return '<';
else {
nextChar();
return TK_LE;
}
}
case '>': {
nextChar();
if (current != '=')
return '>';
else {
nextChar();
return TK_GE;
}
}
case '~': {
nextChar();
if (current != '=')
return '~';
else {
nextChar();
return TK_NE;
}
}
case ':': {
nextChar();
if (current != ':')
return ':';
else {
nextChar();
return TK_DBCOLON;
}
}
case '"':
case '\'': {
read_string(current, seminfo);
return TK_STRING;
}
case '.': {
save_and_next();
if (check_next(".")) {
if (check_next("."))
return TK_DOTS; /* ... */
else
return TK_CONCAT; /* .. */
} else if (!isdigit(current))
return '.';
else {
read_numeral(seminfo);
return TK_NUMBER;
}
}
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9': {
read_numeral(seminfo);
return TK_NUMBER;
}
case EOZ: {
return TK_EOS;
}
default: {
if (isspace(current)) {
LuaC._assert (!currIsNewline());
nextChar();
continue;
} else if (isdigit(current)) {
read_numeral(seminfo);
return TK_NUMBER;
} else if (isalpha(current) || current == '_') {
/* identifier or reserved word */
LuaString ts;
do {
save_and_next();
} while (isalnum(current) || current == '_');
ts = newstring(buff, 0, nbuff);
if ( RESERVED.containsKey(ts) )
return ((Integer)RESERVED.get(ts)).intValue();
else {
seminfo.ts = ts;
return TK_NAME;
}
} else {
int c = current;
nextChar();
return c; /* single-char tokens (+ - / ...) */
}
}
}
}
}
void next() {
lastline = linenumber;
if (lookahead.token != TK_EOS) { /* is there a look-ahead token? */
t.set( lookahead ); /* use this one */
lookahead.token = TK_EOS; /* and discharge it */
} else
t.token = llex(t.seminfo); /* read next token */
}
void lookahead() {
LuaC._assert (lookahead.token == TK_EOS);
lookahead.token = llex(lookahead.seminfo);
}
// =============================================================
// from lcode.h
// =============================================================
// =============================================================
// from lparser.c
// =============================================================
static final boolean vkisvar(final int k) {
return (VLOCAL <= (k) && (k) <= VINDEXED);
}
static final boolean vkisinreg(final int k) {
return ((k) == VNONRELOC || (k) == VLOCAL);
}
static class expdesc {
int k; // expkind, from enumerated list, above
static class U { // originally a union
short ind_idx; // index (R/K)
short ind_t; // table(register or upvalue)
short ind_vt; // whether 't' is register (VLOCAL) or (UPVALUE)
private LuaValue _nval;
int info;
public void setNval(LuaValue r) {
_nval = r;
}
public LuaValue nval() {
return (_nval == null? LuaInteger.valueOf(info): _nval);
}
};
final U u = new U();
final IntPtr t = new IntPtr(); /* patch list of `exit when true' */
final IntPtr f = new IntPtr(); /* patch list of `exit when false' */
void init( int k, int i ) {
this.f.i = NO_JUMP;
this.t.i = NO_JUMP;
this.k = k;
this.u.info = i;
}
boolean hasjumps() {
return (t.i != f.i);
}
boolean isnumeral() {
return (k == VKNUM && t.i == NO_JUMP && f.i == NO_JUMP);
}
public void setvalue(expdesc other) {
this.f.i = other.f.i;
this.k = other.k;
this.t.i = other.t.i;
this.u._nval = other.u._nval;
this.u.ind_idx = other.u.ind_idx;
this.u.ind_t = other.u.ind_t;
this.u.ind_vt = other.u.ind_vt;
this.u.info = other.u.info;
}
}
/* description of active local variable */
static class Vardesc {
final short idx; /* variable index in stack */
Vardesc(int idx) {
this.idx = (short) idx;
}
};
/* description of pending goto statements and label statements */
static class Labeldesc {
LuaString name; /* label identifier */
int pc; /* position in code */
int line; /* line where it appeared */
short nactvar; /* local level where it appears in current block */
public Labeldesc(LuaString name, int pc, int line, short nactvar) {
this.name = name;
this.pc = pc;
this.line = line;
this.nactvar = nactvar;
}
};
/* dynamic structures used by the parser */
static class Dyndata {
Vardesc[] actvar; /* list of active local variables */
int n_actvar = 0;
Labeldesc[] gt; /* list of pending gotos */
int n_gt = 0;
Labeldesc[] label; /* list of active labels */
int n_label = 0;
};
boolean hasmultret(int k) {
return ((k) == VCALL || (k) == VVARARG);
}
/*----------------------------------------------------------------------
name args description
------------------------------------------------------------------------*/
void anchor_token () {
/* last token from outer function must be EOS */
LuaC._assert(fs != null || t.token == TK_EOS);
if (t.token == TK_NAME || t.token == TK_STRING) {
LuaString ts = t.seminfo.ts;
// TODO: is this necessary?
L.cachedLuaString(t.seminfo.ts);
}
}
/* semantic error */
void semerror (String msg) {
t.token = 0; /* remove 'near to' from final message */
syntaxerror(msg);
}
void error_expected(int token) {
syntaxerror(L.pushfstring(LUA_QS(token2str(token)) + " expected"));
}
boolean testnext(int c) {
if (t.token == c) {
next();
return true;
} else
return false;
}
void check(int c) {
if (t.token != c)
error_expected(c);
}
void checknext (int c) {
check(c);
next();
}
void check_condition(boolean c, String msg) {
if (!(c))
syntaxerror(msg);
}
void check_match(int what, int who, int where) {
if (!testnext(what)) {
if (where == linenumber)
error_expected(what);
else {
syntaxerror(L.pushfstring(LUA_QS(token2str(what))
+ " expected " + "(to close " + LUA_QS(token2str(who))
+ " at line " + where + ")"));
}
}
}
LuaString str_checkname() {
LuaString ts;
check(TK_NAME);
ts = t.seminfo.ts;
next();
return ts;
}
void codestring(expdesc e, LuaString s) {
e.init(VK, fs.stringK(s));
}
void checkname(expdesc e) {
codestring(e, str_checkname());
}
int registerlocalvar(LuaString varname) {
FuncState fs = this.fs;
Prototype f = fs.f;
if (f.locvars == null || fs.nlocvars + 1 > f.locvars.length)
f.locvars = LuaC.realloc( f.locvars, fs.nlocvars*2+1 );
f.locvars[fs.nlocvars] = new LocVars(varname,0,0);
return fs.nlocvars++;
}
void new_localvar(LuaString name) {
int reg = registerlocalvar(name);
fs.checklimit(dyd.n_actvar + 1, FuncState.LUAI_MAXVARS, "local variables");
if (dyd.actvar == null || dyd.n_actvar + 1 > dyd.actvar.length)
dyd.actvar = LuaC.realloc(dyd.actvar, Math.max(1, dyd.n_actvar * 2));
dyd.actvar[dyd.n_actvar++] = new Vardesc(reg);
}
void new_localvarliteral(String v) {
LuaString ts = newstring(v);
new_localvar(ts);
}
void adjustlocalvars(int nvars) {
FuncState fs = this.fs;
fs.nactvar = (short) (fs.nactvar + nvars);
for (; nvars > 0; nvars--) {
fs.getlocvar(fs.nactvar - nvars).startpc = fs.pc;
}
}
void removevars(int tolevel) {
FuncState fs = this.fs;
while (fs.nactvar > tolevel)
fs.getlocvar(--fs.nactvar).endpc = fs.pc;
}
void singlevar(expdesc var) {
LuaString varname = this.str_checkname();
FuncState fs = this.fs;
if (FuncState.singlevaraux(fs, varname, var, 1) == VVOID) { /* global name? */
expdesc key = new expdesc();
FuncState.singlevaraux(fs, this.envn, var, 1); /* get environment variable */
LuaC._assert(var.k == VLOCAL || var.k == VUPVAL);
this.codestring(key, varname); /* key is variable name */
fs.indexed(var, key); /* env[varname] */
}
}
void adjust_assign(int nvars, int nexps, expdesc e) {
FuncState fs = this.fs;
int extra = nvars - nexps;
if (hasmultret(e.k)) {
/* includes call itself */
extra++;
if (extra < 0)
extra = 0;
/* last exp. provides the difference */
fs.setreturns(e, extra);
if (extra > 1)
fs.reserveregs(extra - 1);
} else {
/* close last expression */
if (e.k != VVOID)
fs.exp2nextreg(e);
if (extra > 0) {
int reg = fs.freereg;
fs.reserveregs(extra);
fs.nil(reg, extra);
}
}
}
void enterlevel() {
if (++L.nCcalls > LUAI_MAXCCALLS)
lexerror("chunk has too many syntax levels", 0);
}
void leavelevel() {
L.nCcalls--;
}
void closegoto(int g, Labeldesc label) {
FuncState fs = this.fs;
Labeldesc[] gl = this.dyd.gt;
Labeldesc gt = gl[g];
LuaC._assert(gt.name.eq_b(label.name));
if (gt.nactvar < label.nactvar) {
LuaString vname = fs.getlocvar(gt.nactvar).varname;
String msg = L.pushfstring(" at line "
+ gt.line + " jumps into the scope of local '"
+ vname.tojstring() + "'");
semerror(msg);
}
fs.patchlist(gt.pc, label.pc);
/* remove goto from pending list */
System.arraycopy(gl, g + 1, gl, g, this.dyd.n_gt - g - 1);
gl[--this.dyd.n_gt] = null;
}
/*
** try to close a goto with existing labels; this solves backward jumps
*/
boolean findlabel (int g) {
int i;
BlockCnt bl = fs.bl;
Dyndata dyd = this.dyd;
Labeldesc gt = dyd.gt[g];
/* check labels in current block for a match */
for (i = bl.firstlabel; i < dyd.n_label; i++) {
Labeldesc lb = dyd.label[i];
if (lb.name.eq_b(gt.name)) { /* correct label? */
if (gt.nactvar > lb.nactvar &&
(bl.upval || dyd.n_label > bl.firstlabel))
fs.patchclose(gt.pc, lb.nactvar);
closegoto(g, lb); /* close it */
return true;
}
}
return false; /* label not found; cannot close goto */
}
/* Caller must LuaC.grow() the vector before calling this. */
int newlabelentry(Labeldesc[] l, int index, LuaString name, int line, int pc) {
l[index] = new Labeldesc(name, pc, line, fs.nactvar);
return index;
}
/*
** check whether new label 'lb' matches any pending gotos in current
** block; solves forward jumps
*/
void findgotos (Labeldesc lb) {
Labeldesc[] gl = dyd.gt;
int i = fs.bl.firstgoto;
while (i < dyd.n_gt) {
if (gl[i].name.eq_b(lb.name))
closegoto(i, lb);
else
i++;
}
}
/*
** create a label named "break" to resolve break statements
*/
void breaklabel () {
LuaString n = LuaString.valueOf("break");
int l = newlabelentry(dyd.label=LuaC.grow(dyd.label, dyd.n_label+1), dyd.n_label++, n, 0, fs.pc);
findgotos(dyd.label[l]);
}
/*
** generates an error for an undefined 'goto'; choose appropriate
** message when label name is a reserved word (which can only be 'break')
*/
void undefgoto (Labeldesc gt) {
String msg = L.pushfstring(isReservedKeyword(gt.name.tojstring())
? "<"+gt.name+"> at line "+gt.line+" not inside a loop"
: "no visible label '"+gt.name+"' for at line "+gt.line);
semerror(msg);
}
Prototype addprototype () {
Prototype clp;
Prototype f = fs.f; /* prototype of current function */
if (f.p == null || fs.np >= f.p.length) {
f.p = LuaC.realloc(f.p, Math.max(1, fs.np * 2));
}
f.p[fs.np++] = clp = new Prototype();
return clp;
}
void codeclosure (expdesc v) {
FuncState fs = this.fs.prev;
v.init(VRELOCABLE, fs.codeABx(LuaC.OP_CLOSURE, 0, fs.np - 1));
fs.exp2nextreg(v); /* fix it at stack top (for GC) */
}
void open_func (FuncState fs, BlockCnt bl) {
fs.prev = this.fs; /* linked list of funcstates */
fs.ls = this;
this.fs = fs;
fs.pc = 0;
fs.lasttarget = -1;
fs.jpc = new IntPtr( NO_JUMP );
fs.freereg = 0;
fs.nk = 0;
fs.np = 0;
fs.nups = 0;
fs.nlocvars = 0;
fs.nactvar = 0;
fs.firstlocal = dyd.n_actvar;
fs.bl = null;
fs.f.source = this.source;
fs.f.maxstacksize = 2; /* registers 0/1 are always valid */
fs.enterblock(bl, false);
}
void close_func() {
FuncState fs = this.fs;
Prototype f = fs.f;
fs.ret(0, 0); /* final return */
fs.leaveblock();
f.code = LuaC.realloc(f.code, fs.pc);
f.lineinfo = LuaC.realloc(f.lineinfo, fs.pc);
f.k = LuaC.realloc(f.k, fs.nk);
f.p = LuaC.realloc(f.p, fs.np);
f.locvars = LuaC.realloc(f.locvars, fs.nlocvars);
f.upvalues = LuaC.realloc(f.upvalues, fs.nups);
LuaC._assert (fs.bl == null);
this.fs = fs.prev;
// last token read was anchored in defunct function; must reanchor it
// ls.anchor_token();
}
/*============================================================*/
/* GRAMMAR RULES */
/*============================================================*/
void fieldsel(expdesc v) {
/* fieldsel -> ['.' | ':'] NAME */
FuncState fs = this.fs;
expdesc key = new expdesc();
fs.exp2anyregup(v);
this.next(); /* skip the dot or colon */
this.checkname(key);
fs.indexed(v, key);
}
void yindex(expdesc v) {
/* index -> '[' expr ']' */
this.next(); /* skip the '[' */
this.expr(v);
this.fs.exp2val(v);
this.checknext(']');
}
/*
** {======================================================================
** Rules for Constructors
** =======================================================================
*/
static class ConsControl {
expdesc v = new expdesc(); /* last list item read */
expdesc t; /* table descriptor */
int nh; /* total number of `record' elements */
int na; /* total number of array elements */
int tostore; /* number of array elements pending to be stored */
};
void recfield(ConsControl cc) {
/* recfield -> (NAME | `['exp1`]') = exp1 */
FuncState fs = this.fs;
int reg = this.fs.freereg;
expdesc key = new expdesc();
expdesc val = new expdesc();
int rkkey;
if (this.t.token == TK_NAME) {
fs.checklimit(cc.nh, MAX_INT, "items in a constructor");
this.checkname(key);
} else
/* this.t.token == '[' */
this.yindex(key);
cc.nh++;
this.checknext('=');
rkkey = fs.exp2RK(key);
this.expr(val);
fs.codeABC(Lua.OP_SETTABLE, cc.t.u.info, rkkey, fs.exp2RK(val));
fs.freereg = (short)reg; /* free registers */
}
void listfield (ConsControl cc) {
this.expr(cc.v);
fs.checklimit(cc.na, MAX_INT, "items in a constructor");
cc.na++;
cc.tostore++;
}
void constructor(expdesc t) {
/* constructor -> ?? */
FuncState fs = this.fs;
int line = this.linenumber;
int pc = fs.codeABC(Lua.OP_NEWTABLE, 0, 0, 0);
ConsControl cc = new ConsControl();
cc.na = cc.nh = cc.tostore = 0;
cc.t = t;
t.init(VRELOCABLE, pc);
cc.v.init(VVOID, 0); /* no value (yet) */
fs.exp2nextreg(t); /* fix it at stack top (for gc) */
this.checknext('{');
do {
LuaC._assert (cc.v.k == VVOID || cc.tostore > 0);
if (this.t.token == '}')
break;
fs.closelistfield(cc);
switch (this.t.token) {
case TK_NAME: { /* may be listfields or recfields */
this.lookahead();
if (this.lookahead.token != '=') /* expression? */
this.listfield(cc);
else
this.recfield(cc);
break;
}
case '[': { /* constructor_item -> recfield */
this.recfield(cc);
break;
}
default: { /* constructor_part -> listfield */
this.listfield(cc);
break;
}
}
} while (this.testnext(',') || this.testnext(';'));
this.check_match('}', '{', line);
fs.lastlistfield(cc);
InstructionPtr i = new InstructionPtr(fs.f.code, pc);
LuaC.SETARG_B(i, luaO_int2fb(cc.na)); /* set initial array size */
LuaC.SETARG_C(i, luaO_int2fb(cc.nh)); /* set initial table size */
}
/*
** converts an integer to a "floating point byte", represented as
** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
** eeeee != 0 and (xxx) otherwise.
*/
static int luaO_int2fb (int x) {
int e = 0; /* expoent */
while (x >= 16) {
x = (x+1) >> 1;
e++;
}
if (x < 8) return x;
else return ((e+1) << 3) | (((int)x) - 8);
}
/* }====================================================================== */
void parlist () {
/* parlist -> [ param { `,' param } ] */
FuncState fs = this.fs;
Prototype f = fs.f;
int nparams = 0;
f.is_vararg = 0;
if (this.t.token != ')') { /* is `parlist' not empty? */
do {
switch (this.t.token) {
case TK_NAME: { /* param . NAME */
this.new_localvar(this.str_checkname());
++nparams;
break;
}
case TK_DOTS: { /* param . `...' */
this.next();
f.is_vararg = 1;
break;
}
default: this.syntaxerror(" or " + LUA_QL("...") + " expected");
}
} while ((f.is_vararg==0) && this.testnext(','));
}
this.adjustlocalvars(nparams);
f.numparams = fs.nactvar;
fs.reserveregs(fs.nactvar); /* reserve register for parameters */
}
void body(expdesc e, boolean needself, int line) {
/* body -> `(' parlist `)' chunk END */
FuncState new_fs = new FuncState();
BlockCnt bl = new BlockCnt();
new_fs.f = addprototype();
new_fs.f.linedefined = line;
open_func(new_fs, bl);
this.checknext('(');
if (needself) {
new_localvarliteral("self");
adjustlocalvars(1);
}
this.parlist();
this.checknext(')');
this.statlist();
new_fs.f.lastlinedefined = this.linenumber;
this.check_match(TK_END, TK_FUNCTION, line);
this.codeclosure(e);
this.close_func();
}
int explist(expdesc v) {
/* explist1 -> expr { `,' expr } */
int n = 1; /* at least one expression */
this.expr(v);
while (this.testnext(',')) {
fs.exp2nextreg(v);
this.expr(v);
n++;
}
return n;
}
void funcargs(expdesc f, int line) {
FuncState fs = this.fs;
expdesc args = new expdesc();
int base, nparams;
switch (this.t.token) {
case '(': { /* funcargs -> `(' [ explist1 ] `)' */
this.next();
if (this.t.token == ')') /* arg list is empty? */
args.k = VVOID;
else {
this.explist(args);
fs.setmultret(args);
}
this.check_match(')', '(', line);
break;
}
case '{': { /* funcargs -> constructor */
this.constructor(args);
break;
}
case TK_STRING: { /* funcargs -> STRING */
this.codestring(args, this.t.seminfo.ts);
this.next(); /* must use `seminfo' before `next' */
break;
}
default: {
this.syntaxerror("function arguments expected");
return;
}
}
LuaC._assert (f.k == VNONRELOC);
base = f.u.info; /* base register for call */
if (hasmultret(args.k))
nparams = Lua.LUA_MULTRET; /* open call */
else {
if (args.k != VVOID)
fs.exp2nextreg(args); /* close last argument */
nparams = fs.freereg - (base + 1);
}
f.init(VCALL, fs.codeABC(Lua.OP_CALL, base, nparams + 1, 2));
fs.fixline(line);
fs.freereg = (short)(base+1); /* call remove function and arguments and leaves
* (unless changed) one result */
}
/*
** {======================================================================
** Expression parsing
** =======================================================================
*/
void primaryexp (expdesc v) {
/* primaryexp -> NAME | '(' expr ')' */
switch (t.token) {
case '(': {
int line = linenumber;
this.next();
this.expr(v);
this.check_match(')', '(', line);
fs.dischargevars(v);
return;
}
case TK_NAME: {
singlevar(v);
return;
}
default: {
this.syntaxerror("unexpected symbol " + t.token + " (" + ((char) t.token) + ")");
return;
}
}
}
void suffixedexp (expdesc v) {
/* suffixedexp ->
primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */
int line = linenumber;
primaryexp(v);
for (;;) {
switch (t.token) {
case '.': { /* fieldsel */
this.fieldsel(v);
break;
}
case '[': { /* `[' exp1 `]' */
expdesc key = new expdesc();
fs.exp2anyregup(v);
this.yindex(key);
fs.indexed(v, key);
break;
}
case ':': { /* `:' NAME funcargs */
expdesc key = new expdesc();
this.next();
this.checkname(key);
fs.self(v, key);
this.funcargs(v, line);
break;
}
case '(':
case TK_STRING:
case '{': { /* funcargs */
fs.exp2nextreg(v);
this.funcargs(v, line);
break;
}
default:
return;
}
}
}
void simpleexp(expdesc v) {
/*
* simpleexp -> NUMBER | STRING | NIL | true | false | ... | constructor |
* FUNCTION body | primaryexp
*/
switch (this.t.token) {
case TK_NUMBER: {
v.init(VKNUM, 0);
v.u.setNval(this.t.seminfo.r);
break;
}
case TK_STRING: {
this.codestring(v, this.t.seminfo.ts);
break;
}
case TK_NIL: {
v.init(VNIL, 0);
break;
}
case TK_TRUE: {
v.init(VTRUE, 0);
break;
}
case TK_FALSE: {
v.init(VFALSE, 0);
break;
}
case TK_DOTS: { /* vararg */
FuncState fs = this.fs;
this.check_condition(fs.f.is_vararg!=0, "cannot use " + LUA_QL("...")
+ " outside a vararg function");
v.init(VVARARG, fs.codeABC(Lua.OP_VARARG, 0, 1, 0));
break;
}
case '{': { /* constructor */
this.constructor(v);
return;
}
case TK_FUNCTION: {
this.next();
this.body(v, false, this.linenumber);
return;
}
default: {
this.suffixedexp(v);
return;
}
}
this.next();
}
int getunopr(int op) {
switch (op) {
case TK_NOT:
return OPR_NOT;
case '-':
return OPR_MINUS;
case '#':
return OPR_LEN;
default:
return OPR_NOUNOPR;
}
}
int getbinopr(int op) {
switch (op) {
case '+':
return OPR_ADD;
case '-':
return OPR_SUB;
case '*':
return OPR_MUL;
case '/':
return OPR_DIV;
case '%':
return OPR_MOD;
case '^':
return OPR_POW;
case TK_CONCAT:
return OPR_CONCAT;
case TK_NE:
return OPR_NE;
case TK_EQ:
return OPR_EQ;
case '<':
return OPR_LT;
case TK_LE:
return OPR_LE;
case '>':
return OPR_GT;
case TK_GE:
return OPR_GE;
case TK_AND:
return OPR_AND;
case TK_OR:
return OPR_OR;
default:
return OPR_NOBINOPR;
}
}
static class Priority {
final byte left; /* left priority for each binary operator */
final byte right; /* right priority */
public Priority(int i, int j) {
left = (byte) i;
right = (byte) j;
}
};
static Priority[] priority = { /* ORDER OPR */
new Priority(6, 6), new Priority(6, 6), new Priority(7, 7), new Priority(7, 7), new Priority(7, 7), /* `+' `-' `/' `%' */
new Priority(10, 9), new Priority(5, 4), /* power and concat (right associative) */
new Priority(3, 3), new Priority(3, 3), /* equality and inequality */
new Priority(3, 3), new Priority(3, 3), new Priority(3, 3), new Priority(3, 3), /* order */
new Priority(2, 2), new Priority(1, 1) /* logical (and/or) */
};
static final int UNARY_PRIORITY = 8; /* priority for unary operators */
/*
** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
** where `binop' is any binary operator with a priority higher than `limit'
*/
int subexpr(expdesc v, int limit) {
int op;
int uop;
this.enterlevel();
uop = getunopr(this.t.token);
if (uop != OPR_NOUNOPR) {
int line = linenumber;
this.next();
this.subexpr(v, UNARY_PRIORITY);
fs.prefix(uop, v, line);
} else
this.simpleexp(v);
/* expand while operators have priorities higher than `limit' */
op = getbinopr(this.t.token);
while (op != OPR_NOBINOPR && priority[op].left > limit) {
expdesc v2 = new expdesc();
int line = linenumber;
this.next();
fs.infix(op, v);
/* read sub-expression with higher priority */
int nextop = this.subexpr(v2, priority[op].right);
fs.posfix(op, v, v2, line);
op = nextop;
}
this.leavelevel();
return op; /* return first untreated operator */
}
void expr(expdesc v) {
this.subexpr(v, 0);
}
/* }==================================================================== */
/*
** {======================================================================
** Rules for Statements
** =======================================================================
*/
boolean block_follow (boolean withuntil) {
switch (t.token) {
case TK_ELSE: case TK_ELSEIF: case TK_END: case TK_EOS:
return true;
case TK_UNTIL:
return withuntil;
default: return false;
}
}
void block () {
/* block -> chunk */
FuncState fs = this.fs;
BlockCnt bl = new BlockCnt();
fs.enterblock(bl, false);
this.statlist();
fs.leaveblock();
}
/*
** structure to chain all variables in the left-hand side of an
** assignment
*/
static class LHS_assign {
LHS_assign prev;
/* variable (global, local, upvalue, or indexed) */
expdesc v = new expdesc();
};
/*
** check whether, in an assignment to a local variable, the local variable
** is needed in a previous assignment (to a table). If so, save original
** local value in a safe place and use this safe copy in the previous
** assignment.
*/
void check_conflict (LHS_assign lh, expdesc v) {
FuncState fs = this.fs;
short extra = (short) fs.freereg; /* eventual position to save local variable */
boolean conflict = false;
for (; lh!=null; lh = lh.prev) {
if (lh.v.k == VINDEXED) {
/* table is the upvalue/local being assigned now? */
if (lh.v.u.ind_vt == v.k && lh.v.u.ind_t == v.u.info) {
conflict = true;
lh.v.u.ind_vt = VLOCAL;
lh.v.u.ind_t = extra; /* previous assignment will use safe copy */
}
/* index is the local being assigned? (index cannot be upvalue) */
if (v.k == VLOCAL && lh.v.u.ind_idx == v.u.info) {
conflict = true;
lh.v.u.ind_idx = extra; /* previous assignment will use safe copy */
}
}
}
if (conflict) {
/* copy upvalue/local value to a temporary (in position 'extra') */
int op = (v.k == VLOCAL) ? Lua.OP_MOVE : Lua.OP_GETUPVAL;
fs.codeABC(op, extra, v.u.info, 0);
fs.reserveregs(1);
}
}
void assignment (LHS_assign lh, int nvars) {
expdesc e = new expdesc();
this.check_condition(VLOCAL <= lh.v.k && lh.v.k <= VINDEXED,
"syntax error");
if (this.testnext(',')) { /* assignment -> `,' primaryexp assignment */
LHS_assign nv = new LHS_assign();
nv.prev = lh;
this.suffixedexp(nv.v);
if (nv.v.k != VINDEXED)
this.check_conflict(lh, nv.v);
this.assignment(nv, nvars+1);
}
else { /* assignment . `=' explist1 */
int nexps;
this.checknext('=');
nexps = this.explist(e);
if (nexps != nvars) {
this.adjust_assign(nvars, nexps, e);
if (nexps > nvars)
this.fs.freereg -= nexps - nvars; /* remove extra values */
}
else {
fs.setoneret(e); /* close last expression */
fs.storevar(lh.v, e);
return; /* avoid default */
}
}
e.init(VNONRELOC, this.fs.freereg-1); /* default assignment */
fs.storevar(lh.v, e);
}
int cond() {
/* cond -> exp */
expdesc v = new expdesc();
/* read condition */
this.expr(v);
/* `falses' are all equal here */
if (v.k == VNIL)
v.k = VFALSE;
fs.goiftrue(v);
return v.f.i;
}
void gotostat(int pc) {
int line = linenumber;
LuaString label;
int g;
if (testnext(TK_GOTO))
label = str_checkname();
else {
next(); /* skip break */
label = LuaString.valueOf("break");
}
g = newlabelentry(dyd.gt =LuaC.grow(dyd.gt, dyd.n_gt+1), dyd.n_gt++, label, line, pc);
findlabel(g); /* close it if label already defined */
}
/* skip no-op statements */
void skipnoopstat () {
while (t.token == ';' || t.token == TK_DBCOLON)
statement();
}
void labelstat (LuaString label, int line) {
/* label -> '::' NAME '::' */
int l; /* index of new label being created */
fs.checkrepeated(dyd.label, dyd.n_label, label); /* check for repeated labels */
checknext(TK_DBCOLON); /* skip double colon */
/* create new entry for this label */
l = newlabelentry(dyd.label=LuaC.grow(dyd.label, dyd.n_label+1), dyd.n_label++, label, line, fs.pc);
skipnoopstat(); /* skip other no-op statements */
if (block_follow(false)) { /* label is last no-op statement in the block? */
/* assume that locals are already out of scope */
dyd.label[l].nactvar = fs.bl.nactvar;
}
findgotos(dyd.label[l]);
}
void whilestat (int line) {
/* whilestat -> WHILE cond DO block END */
FuncState fs = this.fs;
int whileinit;
int condexit;
BlockCnt bl = new BlockCnt();
this.next(); /* skip WHILE */
whileinit = fs.getlabel();
condexit = this.cond();
fs.enterblock(bl, true);
this.checknext(TK_DO);
this.block();
fs.patchlist(fs.jump(), whileinit);
this.check_match(TK_END, TK_WHILE, line);
fs.leaveblock();
fs.patchtohere(condexit); /* false conditions finish the loop */
}
void repeatstat(int line) {
/* repeatstat -> REPEAT block UNTIL cond */
int condexit;
FuncState fs = this.fs;
int repeat_init = fs.getlabel();
BlockCnt bl1 = new BlockCnt();
BlockCnt bl2 = new BlockCnt();
fs.enterblock(bl1, true); /* loop block */
fs.enterblock(bl2, false); /* scope block */
this.next(); /* skip REPEAT */
this.statlist();
this.check_match(TK_UNTIL, TK_REPEAT, line);
condexit = this.cond(); /* read condition (inside scope block) */
if (bl2.upval) { /* upvalues? */
fs.patchclose(condexit, bl2.nactvar);
}
fs.leaveblock(); /* finish scope */
fs.patchlist(condexit, repeat_init); /* close the loop */
fs.leaveblock(); /* finish loop */
}
int exp1() {
expdesc e = new expdesc();
int k;
this.expr(e);
k = e.k;
fs.exp2nextreg(e);
return k;
}
void forbody(int base, int line, int nvars, boolean isnum) {
/* forbody -> DO block */
BlockCnt bl = new BlockCnt();
FuncState fs = this.fs;
int prep, endfor;
this.adjustlocalvars(3); /* control variables */
this.checknext(TK_DO);
prep = isnum ? fs.codeAsBx(Lua.OP_FORPREP, base, NO_JUMP) : fs.jump();
fs.enterblock(bl, false); /* scope for declared variables */
this.adjustlocalvars(nvars);
fs.reserveregs(nvars);
this.block();
fs.leaveblock(); /* end of scope for declared variables */
fs.patchtohere(prep);
if (isnum) /* numeric for? */
endfor = fs.codeAsBx(Lua.OP_FORLOOP, base, NO_JUMP);
else { /* generic for */
fs.codeABC(Lua.OP_TFORCALL, base, 0, nvars);
fs.fixline(line);
endfor = fs.codeAsBx(Lua.OP_TFORLOOP, base + 2, NO_JUMP);
}
fs.patchlist(endfor, prep + 1);
fs.fixline(line);
}
void fornum(LuaString varname, int line) {
/* fornum -> NAME = exp1,exp1[,exp1] forbody */
FuncState fs = this.fs;
int base = fs.freereg;
this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_INDEX);
this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_LIMIT);
this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_STEP);
this.new_localvar(varname);
this.checknext('=');
this.exp1(); /* initial value */
this.checknext(',');
this.exp1(); /* limit */
if (this.testnext(','))
this.exp1(); /* optional step */
else { /* default step = 1 */
fs.codeABx(Lua.OP_LOADK, fs.freereg, fs.numberK(LuaInteger.valueOf(1)));
fs.reserveregs(1);
}
this.forbody(base, line, 1, true);
}
void forlist(LuaString indexname) {
/* forlist -> NAME {,NAME} IN explist1 forbody */
FuncState fs = this.fs;
expdesc e = new expdesc();
int nvars = 4; /* gen, state, control, plus at least one declared var */
int line;
int base = fs.freereg;
/* create control variables */
this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_GENERATOR);
this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_STATE);
this.new_localvarliteral(RESERVED_LOCAL_VAR_FOR_CONTROL);
/* create declared variables */
this.new_localvar(indexname);
while (this.testnext(',')) {
this.new_localvar(this.str_checkname());
++nvars;
}
this.checknext(TK_IN);
line = this.linenumber;
this.adjust_assign(3, this.explist(e), e);
fs.checkstack(3); /* extra space to call generator */
this.forbody(base, line, nvars - 3, false);
}
void forstat(int line) {
/* forstat -> FOR (fornum | forlist) END */
FuncState fs = this.fs;
LuaString varname;
BlockCnt bl = new BlockCnt();
fs.enterblock(bl, true); /* scope for loop and control variables */
this.next(); /* skip `for' */
varname = this.str_checkname(); /* first variable name */
switch (this.t.token) {
case '=':
this.fornum(varname, line);
break;
case ',':
case TK_IN:
this.forlist(varname);
break;
default:
this.syntaxerror(LUA_QL("=") + " or " + LUA_QL("in") + " expected");
}
this.check_match(TK_END, TK_FOR, line);
fs.leaveblock(); /* loop scope (`break' jumps to this point) */
}
void test_then_block(IntPtr escapelist) {
/* test_then_block -> [IF | ELSEIF] cond THEN block */
expdesc v = new expdesc();
BlockCnt bl = new BlockCnt();
int jf; /* instruction to skip 'then' code (if condition is false) */
this.next(); /* skip IF or ELSEIF */
expr(v); /* read expression */
this.checknext(TK_THEN);
if (t.token == TK_GOTO || t.token == TK_BREAK) {
fs.goiffalse(v); /* will jump to label if condition is true */
fs.enterblock(bl, false); /* must enter block before 'goto' */
gotostat(v.t.i); /* handle goto/break */
skipnoopstat(); /* skip other no-op statements */
if (block_follow(false)) { /* 'goto' is the entire block? */
fs.leaveblock();
return; /* and that is it */
} else
/* must skip over 'then' part if condition is false */
jf = fs.jump();
} else { /* regular case (not goto/break) */
fs.goiftrue(v); /* skip over block if condition is false */
fs.enterblock(bl, false);
jf = v.f.i;
}
statlist(); /* `then' part */
fs.leaveblock();
if (t.token == TK_ELSE || t.token == TK_ELSEIF)
fs.concat(escapelist, fs.jump()); /* must jump over it */
fs.patchtohere(jf);
}
void ifstat(int line) {
IntPtr escapelist = new IntPtr(NO_JUMP); /* exit list for finished parts */
test_then_block(escapelist); /* IF cond THEN block */
while (t.token == TK_ELSEIF)
test_then_block(escapelist); /* ELSEIF cond THEN block */
if (testnext(TK_ELSE))
block(); /* `else' part */
check_match(TK_END, TK_IF, line);
fs.patchtohere(escapelist.i); /* patch escape list to 'if' end */
}
void localfunc() {
expdesc b = new expdesc();
FuncState fs = this.fs;
this.new_localvar(this.str_checkname());
this.adjustlocalvars(1);
this.body(b, false, this.linenumber);
/* debug information will only see the variable after this point! */
fs.getlocvar(fs.nactvar - 1).startpc = fs.pc;
}
void localstat() {
/* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */
int nvars = 0;
int nexps;
expdesc e = new expdesc();
do {
this.new_localvar(this.str_checkname());
++nvars;
} while (this.testnext(','));
if (this.testnext('='))
nexps = this.explist(e);
else {
e.k = VVOID;
nexps = 0;
}
this.adjust_assign(nvars, nexps, e);
this.adjustlocalvars(nvars);
}
boolean funcname(expdesc v) {
/* funcname -> NAME {field} [`:' NAME] */
boolean ismethod = false;
this.singlevar(v);
while (this.t.token == '.')
this.fieldsel(v);
if (this.t.token == ':') {
ismethod = true;
this.fieldsel(v);
}
return ismethod;
}
void funcstat(int line) {
/* funcstat -> FUNCTION funcname body */
boolean needself;
expdesc v = new expdesc();
expdesc b = new expdesc();
this.next(); /* skip FUNCTION */
needself = this.funcname(v);
this.body(b, needself, line);
fs.storevar(v, b);
fs.fixline(line); /* definition `happens' in the first line */
}
void exprstat() {
/* stat -> func | assignment */
FuncState fs = this.fs;
LHS_assign v = new LHS_assign();
this.suffixedexp(v.v);
if (t.token == '=' || t.token == ',') { /* stat -> assignment ? */
v.prev = null;
assignment(v, 1);
}
else { /* stat -> func */
check_condition(v.v.k == VCALL, "syntax error");
LuaC.SETARG_C(fs.getcodePtr(v.v), 1); /* call statement uses no results */
}
}
void retstat() {
/* stat -> RETURN explist */
FuncState fs = this.fs;
expdesc e = new expdesc();
int first, nret; /* registers with returned values */
if (block_follow(true) || this.t.token == ';')
first = nret = 0; /* return no values */
else {
nret = this.explist(e); /* optional return values */
if (hasmultret(e.k)) {
fs.setmultret(e);
if (e.k == VCALL && nret == 1) { /* tail call? */
LuaC.SET_OPCODE(fs.getcodePtr(e), Lua.OP_TAILCALL);
LuaC._assert (Lua.GETARG_A(fs.getcode(e)) == fs.nactvar);
}
first = fs.nactvar;
nret = Lua.LUA_MULTRET; /* return all values */
} else {
if (nret == 1) /* only one single value? */
first = fs.exp2anyreg(e);
else {
fs.exp2nextreg(e); /* values must go to the `stack' */
first = fs.nactvar; /* return all `active' values */
LuaC._assert (nret == fs.freereg - first);
}
}
}
fs.ret(first, nret);
testnext(';'); /* skip optional semicolon */
}
void statement() {
int line = this.linenumber; /* may be needed for error messages */
enterlevel();
switch (this.t.token) {
case ';': { /* stat -> ';' (empty statement) */
next(); /* skip ';' */
break;
}
case TK_IF: { /* stat -> ifstat */
this.ifstat(line);
break;
}
case TK_WHILE: { /* stat -> whilestat */
this.whilestat(line);
break;
}
case TK_DO: { /* stat -> DO block END */
this.next(); /* skip DO */
this.block();
this.check_match(TK_END, TK_DO, line);
break;
}
case TK_FOR: { /* stat -> forstat */
this.forstat(line);
break;
}
case TK_REPEAT: { /* stat -> repeatstat */
this.repeatstat(line);
break;
}
case TK_FUNCTION: {
this.funcstat(line); /* stat -> funcstat */
break;
}
case TK_LOCAL: { /* stat -> localstat */
this.next(); /* skip LOCAL */
if (this.testnext(TK_FUNCTION)) /* local function? */
this.localfunc();
else
this.localstat();
break;
}
case TK_DBCOLON: { /* stat -> label */
next(); /* skip double colon */
labelstat(str_checkname(), line);
break;
}
case TK_RETURN: { /* stat -> retstat */
next(); /* skip RETURN */
this.retstat();
break;
}
case TK_BREAK:
case TK_GOTO: { /* stat -> breakstat */
this.gotostat(fs.jump());
break;
}
default: {
this.exprstat();
break;
}
}
LuaC._assert(fs.f.maxstacksize >= fs.freereg
&& fs.freereg >= fs.nactvar);
fs.freereg = fs.nactvar; /* free registers */
leavelevel();
}
void statlist() {
/* statlist -> { stat [`;'] } */
while (!block_follow(true)) {
if (t.token == TK_RETURN) {
statement();
return; /* 'return' must be last statement */
}
statement();
}
}
/*
** compiles the main function, which is a regular vararg function with an
** upvalue named LUA_ENV
*/
public void mainfunc(FuncState funcstate) {
BlockCnt bl = new BlockCnt();
open_func(funcstate, bl);
fs.f.is_vararg = 1; /* main function is always vararg */
expdesc v = new expdesc();
v.init(VLOCAL, 0); /* create and... */
fs.newupvalue(envn, v); /* ...set environment upvalue */
next(); /* read first token */
statlist(); /* parse main body */
check(TK_EOS);
close_func();
}
/* }====================================================================== */
}
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