lobject.c
(5.4.6)
/*
** $Id: lobject.c $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/
#define lobject_c
#define LUA_CORE
#include "lprefix.h"
#include <locale.h>
#include <math.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "lua.h"
#include "lctype.h"
#include "ldebug.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "lvm.h"
/*
** Computes ceil(log2(x))
*/
int luaO_ceillog2 (unsigned int x) {
static const lu_byte log_2[256] = { /* log_2[i] = ceil(log2(i - 1)) */
0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
};
int l = 0;
x--;
while (x >= 256) { l += 8; x >>= 8; }
return l + log_2[x];
}
static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
lua_Integer v2) {
switch (op) {
case LUA_OPADD: return intop(+, v1, v2);
case LUA_OPSUB:return intop(-, v1, v2);
case LUA_OPMUL:return intop(*, v1, v2);
case LUA_OPMOD: return luaV_mod(L, v1, v2);
case LUA_OPIDIV: return luaV_idiv(L, v1, v2);
case LUA_OPBAND: return intop(&, v1, v2);
case LUA_OPBOR: return intop(|, v1, v2);
case LUA_OPBXOR: return intop(^, v1, v2);
case LUA_OPSHL: return luaV_shiftl(v1, v2);
case LUA_OPSHR: return luaV_shiftr(v1, v2);
case LUA_OPUNM: return intop(-, 0, v1);
case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
default: lua_assert(0); return 0;
}
}
static lua_Number numarith (lua_State *L, int op, lua_Number v1,
lua_Number v2) {
switch (op) {
case LUA_OPADD: return luai_numadd(L, v1, v2);
case LUA_OPSUB: return luai_numsub(L, v1, v2);
case LUA_OPMUL: return luai_nummul(L, v1, v2);
case LUA_OPDIV: return luai_numdiv(L, v1, v2);
case LUA_OPPOW: return luai_numpow(L, v1, v2);
case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
case LUA_OPUNM: return luai_numunm(L, v1);
case LUA_OPMOD: return luaV_modf(L, v1, v2);
default: lua_assert(0); return 0;
}
}
int luaO_rawarith (lua_State *L, int op, const TValue *p1, const TValue *p2,
TValue *res) {
switch (op) {
case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
case LUA_OPSHL: case LUA_OPSHR:
case LUA_OPBNOT: { /* operate only on integers */
lua_Integer i1; lua_Integer i2;
if (tointegerns(p1, &i1) && tointegerns(p2, &i2)) {
setivalue(res, intarith(L, op, i1, i2));
return 1;
}
else return 0; /* fail */
}
case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */
lua_Number n1; lua_Number n2;
if (tonumberns(p1, n1) && tonumberns(p2, n2)) {
setfltvalue(res, numarith(L, op, n1, n2));
return 1;
}
else return 0; /* fail */
}
default: { /* other operations */
lua_Number n1; lua_Number n2;
if (ttisinteger(p1) && ttisinteger(p2)) {
setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
return 1;
}
else if (tonumberns(p1, n1) && tonumberns(p2, n2)) {
setfltvalue(res, numarith(L, op, n1, n2));
return 1;
}
else return 0; /* fail */
}
}
}
void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
StkId res) {
if (!luaO_rawarith(L, op, p1, p2, s2v(res))) {
/* could not perform raw operation; try metamethod */
luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
}
}
int luaO_hexavalue (int c) {
if (lisdigit(c)) return c - '0';
else return (ltolower(c) - 'a') + 10;
}
static int isneg (const char **s) {
if (**s == '-') { (*s)++; return 1; }
else if (**s == '+') (*s)++;
return 0;
}
/*
** {==================================================================
** Lua's implementation for 'lua_strx2number'
** ===================================================================
*/
#if !defined(lua_strx2number)
/* maximum number of significant digits to read (to avoid overflows
even with single floats) */
#define MAXSIGDIG 30
/*
** convert a hexadecimal numeric string to a number, following
** C99 specification for 'strtod'
*/
static lua_Number lua_strx2number (const char *s, char **endptr) {
int dot = lua_getlocaledecpoint();
lua_Number r = l_mathop(0.0); /* result (accumulator) */
int sigdig = 0; /* number of significant digits */
int nosigdig = 0; /* number of non-significant digits */
int e = 0; /* exponent correction */
int neg; /* 1 if number is negative */
int hasdot = 0; /* true after seen a dot */
*endptr = cast_charp(s); /* nothing is valid yet */
while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
neg = isneg(&s); /* check sign */
if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */
return l_mathop(0.0); /* invalid format (no '0x') */
for (s += 2; ; s++) { /* skip '0x' and read numeral */
if (*s == dot) {
if (hasdot) break; /* second dot? stop loop */
else hasdot = 1;
}
else if (lisxdigit(cast_uchar(*s))) {
if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */
nosigdig++;
else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */
r = (r * l_mathop(16.0)) + luaO_hexavalue(*s);
else e++; /* too many digits; ignore, but still count for exponent */
if (hasdot) e--; /* decimal digit? correct exponent */
}
else break; /* neither a dot nor a digit */
}
if (nosigdig + sigdig == 0) /* no digits? */
return l_mathop(0.0); /* invalid format */
*endptr = cast_charp(s); /* valid up to here */
e *= 4; /* each digit multiplies/divides value by 2^4 */
if (*s == 'p' || *s == 'P') { /* exponent part? */
int exp1 = 0; /* exponent value */
int neg1; /* exponent sign */
s++; /* skip 'p' */
neg1 = isneg(&s); /* sign */
if (!lisdigit(cast_uchar(*s)))
return l_mathop(0.0); /* invalid; must have at least one digit */
while (lisdigit(cast_uchar(*s))) /* read exponent */
exp1 = exp1 * 10 + *(s++) - '0';
if (neg1) exp1 = -exp1;
e += exp1;
*endptr = cast_charp(s); /* valid up to here */
}
if (neg) r = -r;
return l_mathop(ldexp)(r, e);
}
#endif
/* }====================================================== */
/* maximum length of a numeral to be converted to a number */
#if !defined (L_MAXLENNUM)
#define L_MAXLENNUM 200
#endif
/*
** Convert string 's' to a Lua number (put in 'result'). Return NULL on
** fail or the address of the ending '\0' on success. ('mode' == 'x')
** means a hexadecimal numeral.
*/
static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
char *endptr;
*result = (mode == 'x') ? lua_strx2number(s, &endptr) /* try to convert */
: lua_str2number(s, &endptr);
if (endptr == s) return NULL; /* nothing recognized? */
while (lisspace(cast_uchar(*endptr))) endptr++; /* skip trailing spaces */
return (*endptr == '\0') ? endptr : NULL; /* OK iff no trailing chars */
}
/*
** Convert string 's' to a Lua number (put in 'result') handling the
** current locale.
** This function accepts both the current locale or a dot as the radix
** mark. If the conversion fails, it may mean number has a dot but
** locale accepts something else. In that case, the code copies 's'
** to a buffer (because 's' is read-only), changes the dot to the
** current locale radix mark, and tries to convert again.
** The variable 'mode' checks for special characters in the string:
** - 'n' means 'inf' or 'nan' (which should be rejected)
** - 'x' means a hexadecimal numeral
** - '.' just optimizes the search for the common case (no special chars)
*/
static const char *l_str2d (const char *s, lua_Number *result) {
const char *endptr;
const char *pmode = strpbrk(s, ".xXnN"); /* look for special chars */
int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
if (mode == 'n') /* reject 'inf' and 'nan' */
return NULL;
endptr = l_str2dloc(s, result, mode); /* try to convert */
if (endptr == NULL) { /* failed? may be a different locale */
char buff[L_MAXLENNUM + 1];
const char *pdot = strchr(s, '.');
if (pdot == NULL || strlen(s) > L_MAXLENNUM)
return NULL; /* string too long or no dot; fail */
strcpy(buff, s); /* copy string to buffer */
buff[pdot - s] = lua_getlocaledecpoint(); /* correct decimal point */
endptr = l_str2dloc(buff, result, mode); /* try again */
if (endptr != NULL)
endptr = s + (endptr - buff); /* make relative to 's' */
}
return endptr;
}
#define MAXBY10 cast(lua_Unsigned, LUA_MAXINTEGER / 10)
#define MAXLASTD cast_int(LUA_MAXINTEGER % 10)
static const char *l_str2int (const char *s, lua_Integer *result) {
lua_Unsigned a = 0;
int empty = 1;
int neg;
while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
neg = isneg(&s);
if (s[0] == '0' &&
(s[1] == 'x' || s[1] == 'X')) { /* hex? */
s += 2; /* skip '0x' */
for (; lisxdigit(cast_uchar(*s)); s++) {
a = a * 16 + luaO_hexavalue(*s);
empty = 0;
}
}
else { /* decimal */
for (; lisdigit(cast_uchar(*s)); s++) {
int d = *s - '0';
if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg)) /* overflow? */
return NULL; /* do not accept it (as integer) */
a = a * 10 + d;
empty = 0;
}
}
while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */
if (empty || *s != '\0') return NULL; /* something wrong in the numeral */
else {
*result = l_castU2S((neg) ? 0u - a : a);
return s;
}
}
size_t luaO_str2num (const char *s, TValue *o) {
lua_Integer i; lua_Number n;
const char *e;
if ((e = l_str2int(s, &i)) != NULL) { /* try as an integer */
setivalue(o, i);
}
else if ((e = l_str2d(s, &n)) != NULL) { /* else try as a float */
setfltvalue(o, n);
}
else
return 0; /* conversion failed */
return (e - s) + 1; /* success; return string size */
}
int luaO_utf8esc (char *buff, unsigned long x) {
int n = 1; /* number of bytes put in buffer (backwards) */
lua_assert(x <= 0x7FFFFFFFu);
if (x < 0x80) /* ascii? */
buff[UTF8BUFFSZ - 1] = cast_char(x);
else { /* need continuation bytes */
unsigned int mfb = 0x3f; /* maximum that fits in first byte */
do { /* add continuation bytes */
buff[UTF8BUFFSZ - (n++)] = cast_char(0x80 | (x & 0x3f));
x >>= 6; /* remove added bits */
mfb >>= 1; /* now there is one less bit available in first byte */
} while (x > mfb); /* still needs continuation byte? */
buff[UTF8BUFFSZ - n] = cast_char((~mfb << 1) | x); /* add first byte */
}
return n;
}
/*
** Maximum length of the conversion of a number to a string. Must be
** enough to accommodate both LUA_INTEGER_FMT and LUA_NUMBER_FMT.
** (For a long long int, this is 19 digits plus a sign and a final '\0',
** adding to 21. For a long double, it can go to a sign, 33 digits,
** the dot, an exponent letter, an exponent sign, 5 exponent digits,
** and a final '\0', adding to 43.)
*/
#define MAXNUMBER2STR 44
/*
** Convert a number object to a string, adding it to a buffer
*/
static int tostringbuff (TValue *obj, char *buff) {
int len;
lua_assert(ttisnumber(obj));
if (ttisinteger(obj))
len = lua_integer2str(buff, MAXNUMBER2STR, ivalue(obj));
else {
len = lua_number2str(buff, MAXNUMBER2STR, fltvalue(obj));
if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */
buff[len++] = lua_getlocaledecpoint();
buff[len++] = '0'; /* adds '.0' to result */
}
}
return len;
}
/*
** Convert a number object to a Lua string, replacing the value at 'obj'
*/
void luaO_tostring (lua_State *L, TValue *obj) {
char buff[MAXNUMBER2STR];
int len = tostringbuff(obj, buff);
setsvalue(L, obj, luaS_newlstr(L, buff, len));
}
/*
** {==================================================================
** 'luaO_pushvfstring'
** ===================================================================
*/
/*
** Size for buffer space used by 'luaO_pushvfstring'. It should be
** (LUA_IDSIZE + MAXNUMBER2STR) + a minimal space for basic messages,
** so that 'luaG_addinfo' can work directly on the buffer.
*/
#define BUFVFS (LUA_IDSIZE + MAXNUMBER2STR + 95)
/* buffer used by 'luaO_pushvfstring' */
typedef struct BuffFS {
lua_State *L;
int pushed; /* true if there is a part of the result on the stack */
int blen; /* length of partial string in 'space' */
char space[BUFVFS]; /* holds last part of the result */
} BuffFS;
/*
** Push given string to the stack, as part of the result, and
** join it to previous partial result if there is one.
** It may call 'luaV_concat' while using one slot from EXTRA_STACK.
** This call cannot invoke metamethods, as both operands must be
** strings. It can, however, raise an error if the result is too
** long. In that case, 'luaV_concat' frees the extra slot before
** raising the error.
*/
static void pushstr (BuffFS *buff, const char *str, size_t lstr) {
lua_State *L = buff->L;
setsvalue2s(L, L->top.p, luaS_newlstr(L, str, lstr));
L->top.p++; /* may use one slot from EXTRA_STACK */
if (!buff->pushed) /* no previous string on the stack? */
buff->pushed = 1; /* now there is one */
else /* join previous string with new one */
luaV_concat(L, 2);
}
/*
** empty the buffer space into the stack
*/
static void clearbuff (BuffFS *buff) {
pushstr(buff, buff->space, buff->blen); /* push buffer contents */
buff->blen = 0; /* space now is empty */
}
/*
** Get a space of size 'sz' in the buffer. If buffer has not enough
** space, empty it. 'sz' must fit in an empty buffer.
*/
static char *getbuff (BuffFS *buff, int sz) {
lua_assert(buff->blen <= BUFVFS); lua_assert(sz <= BUFVFS);
if (sz > BUFVFS - buff->blen) /* not enough space? */
clearbuff(buff);
return buff->space + buff->blen;
}
#define addsize(b,sz) ((b)->blen += (sz))
/*
** Add 'str' to the buffer. If string is larger than the buffer space,
** push the string directly to the stack.
*/
static void addstr2buff (BuffFS *buff, const char *str, size_t slen) {
if (slen <= BUFVFS) { /* does string fit into buffer? */
char *bf = getbuff(buff, cast_int(slen));
memcpy(bf, str, slen); /* add string to buffer */
addsize(buff, cast_int(slen));
}
else { /* string larger than buffer */
clearbuff(buff); /* string comes after buffer's content */
pushstr(buff, str, slen); /* push string */
}
}
/*
** Add a numeral to the buffer.
*/
static void addnum2buff (BuffFS *buff, TValue *num) {
char *numbuff = getbuff(buff, MAXNUMBER2STR);
int len = tostringbuff(num, numbuff); /* format number into 'numbuff' */
addsize(buff, len);
}
/*
** this function handles only '%d', '%c', '%f', '%p', '%s', and '%%'
conventional formats, plus Lua-specific '%I' and '%U'
*/
const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
BuffFS buff; /* holds last part of the result */
const char *e; /* points to next '%' */
buff.pushed = buff.blen = 0;
buff.L = L;
while ((e = strchr(fmt, '%')) != NULL) {
addstr2buff(&buff, fmt, e - fmt); /* add 'fmt' up to '%' */
switch (*(e + 1)) { /* conversion specifier */
case 's': { /* zero-terminated string */
const char *s = va_arg(argp, char *);
if (s == NULL) s = "(null)";
addstr2buff(&buff, s, strlen(s));
break;
}
case 'c': { /* an 'int' as a character */
char c = cast_uchar(va_arg(argp, int));
addstr2buff(&buff, &c, sizeof(char));
break;
}
case 'd': { /* an 'int' */
TValue num;
setivalue(&num, va_arg(argp, int));
addnum2buff(&buff, &num);
break;
}
case 'I': { /* a 'lua_Integer' */
TValue num;
setivalue(&num, cast(lua_Integer, va_arg(argp, l_uacInt)));
addnum2buff(&buff, &num);
break;
}
case 'f': { /* a 'lua_Number' */
TValue num;
setfltvalue(&num, cast_num(va_arg(argp, l_uacNumber)));
addnum2buff(&buff, &num);
break;
}
case 'p': { /* a pointer */
const int sz = 3 * sizeof(void*) + 8; /* enough space for '%p' */
char *bf = getbuff(&buff, sz);
void *p = va_arg(argp, void *);
int len = lua_pointer2str(bf, sz, p);
addsize(&buff, len);
break;
}
case 'U': { /* a 'long' as a UTF-8 sequence */
char bf[UTF8BUFFSZ];
int len = luaO_utf8esc(bf, va_arg(argp, long));
addstr2buff(&buff, bf + UTF8BUFFSZ - len, len);
break;
}
case '%': {
addstr2buff(&buff, "%", 1);
break;
}
default: {
luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
*(e + 1));
}
}
fmt = e + 2; /* skip '%' and the specifier */
}
addstr2buff(&buff, fmt, strlen(fmt)); /* rest of 'fmt' */
clearbuff(&buff); /* empty buffer into the stack */
lua_assert(buff.pushed == 1);
return svalue(s2v(L->top.p - 1));
}
const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
const char *msg;
va_list argp;
va_start(argp, fmt);
msg = luaO_pushvfstring(L, fmt, argp);
va_end(argp);
return msg;
}
/* }================================================================== */
#define RETS "..."
#define PRE "[string \""
#define POS "\"]"
#define addstr(a,b,l) ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
void luaO_chunkid (char *out, const char *source, size_t srclen) {
size_t bufflen = LUA_IDSIZE; /* free space in buffer */
if (*source == '=') { /* 'literal' source */
if (srclen <= bufflen) /* small enough? */
memcpy(out, source + 1, srclen * sizeof(char));
else { /* truncate it */
addstr(out, source + 1, bufflen - 1);
*out = '\0';
}
}
else if (*source == '@') { /* file name */
if (srclen <= bufflen) /* small enough? */
memcpy(out, source + 1, srclen * sizeof(char));
else { /* add '...' before rest of name */
addstr(out, RETS, LL(RETS));
bufflen -= LL(RETS);
memcpy(out, source + 1 + srclen - bufflen, bufflen * sizeof(char));
}
}
else { /* string; format as [string "source"] */
const char *nl = strchr(source, '\n'); /* find first new line (if any) */
addstr(out, PRE, LL(PRE)); /* add prefix */
bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */
if (srclen < bufflen && nl == NULL) { /* small one-line source? */
addstr(out, source, srclen); /* keep it */
}
else {
if (nl != NULL) srclen = nl - source; /* stop at first newline */
if (srclen > bufflen) srclen = bufflen;
addstr(out, source, srclen);
addstr(out, RETS, LL(RETS));
}
memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
}
}