/* ** $Id: lobject.c,v 2.118 2017/10/10 20:05:40 roberto Exp roberto $ ** Some generic functions over Lua objects ** See Copyright Notice in lua.h */ #define lobject_c #define LUA_CORE #include "lprefix.h" #include #include #include #include #include #include #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" LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT}; /* ** 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. */ int luaO_int2fb (unsigned int x) { int e = 0; /* exponent */ if (x < 8) return x; while (x >= (8 << 4)) { /* coarse steps */ x = (x + 0xf) >> 4; /* x = ceil(x / 16) */ e += 4; } while (x >= (8 << 1)) { /* fine steps */ x = (x + 1) >> 1; /* x = ceil(x / 2) */ e++; } return ((e+1) << 3) | (cast_int(x) - 8); } /* converts back */ int luaO_fb2int (int x) { return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1); } /* ** 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_div(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_shiftl(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: { lua_Number m; luai_nummod(L, v1, v2, m); return m; } 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 an 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 = 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(char *, s); /* nothing is valid yet */ while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */ neg = isneg(&s); /* check signal */ if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */ return 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 * cast_num(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 0.0; /* invalid format */ *endptr = cast(char *, 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 signal */ s++; /* skip 'p' */ neg1 = isneg(&s); /* signal */ if (!lisdigit(cast_uchar(*s))) return 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(char *, s); /* valid up to here */ } if (neg) r = -r; return l_mathop(ldexp)(r, e); } #endif /* }====================================================== */ /* maximum length of a numeral */ #if !defined (L_MAXLENNUM) #define L_MAXLENNUM 200 #endif 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 if no trailing characters */ } /* ** Convert string 's' to a Lua number (put in 'result'). Return NULL ** on fail or the address of the ending '\0' on success. ** 'pmode' points to (and 'mode' contains) special things in the string: ** - 'x'/'X' means an hexadecimal numeral ** - 'n'/'N' means 'inf' or 'nan' (which should be rejected) ** - '.' just optimizes the search for the common case (nothing special) ** This function accepts both the current locale or a dot as the radix ** mark. If the convertion 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. */ static const char *l_str2d (const char *s, lua_Number *result) { const char *endptr; const char *pmode = strpbrk(s, ".xXnN"); 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 (strlen(s) > L_MAXLENNUM || pdot == NULL) 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 <= 0x10FFFF); 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 */ #define MAXNUMBER2STR 50 /* ** Convert a number object to a string */ void luaO_tostring (lua_State *L, TValue *obj) { char buff[MAXNUMBER2STR]; size_t len; lua_assert(ttisnumber(obj)); if (ttisinteger(obj)) len = lua_integer2str(buff, sizeof(buff), ivalue(obj)); else { len = lua_number2str(buff, sizeof(buff), fltvalue(obj)); #if !defined(LUA_COMPAT_FLOATSTRING) if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */ buff[len++] = lua_getlocaledecpoint(); buff[len++] = '0'; /* adds '.0' to result */ } #endif } setsvalue(L, obj, luaS_newlstr(L, buff, len)); } static void pushstr (lua_State *L, const char *str, size_t l) { setsvalue2s(L, L->top, luaS_newlstr(L, str, l)); luaD_inctop(L); } /* ** this function handles only '%d', '%c', '%f', '%p', and '%s' conventional formats, plus Lua-specific '%I' and '%U' */ const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) { int n = 0; for (;;) { const char *e = strchr(fmt, '%'); if (e == NULL) break; pushstr(L, fmt, e - fmt); switch (*(e+1)) { case 's': { /* zero-terminated string */ const char *s = va_arg(argp, char *); if (s == NULL) s = "(null)"; pushstr(L, s, strlen(s)); break; } case 'c': { /* an 'int' as a character */ char buff = cast(char, va_arg(argp, int)); if (lisprint(cast_uchar(buff))) pushstr(L, &buff, 1); else /* non-printable character; print its code */ luaO_pushfstring(L, "<\\%d>", cast_uchar(buff)); break; } case 'd': { /* an 'int' */ setivalue(s2v(L->top), va_arg(argp, int)); goto top2str; } case 'I': { /* a 'lua_Integer' */ setivalue(s2v(L->top), cast(lua_Integer, va_arg(argp, l_uacInt))); goto top2str; } case 'f': { /* a 'lua_Number' */ setfltvalue(s2v(L->top), cast_num(va_arg(argp, l_uacNumber))); top2str: /* convert the top element to a string */ luaD_inctop(L); luaO_tostring(L, s2v(L->top - 1)); break; } case 'p': { /* a pointer */ char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */ void *p = va_arg(argp, void *); int l = lua_pointer2str(buff, sizeof(buff), p); pushstr(L, buff, l); break; } case 'U': { /* an 'int' as a UTF-8 sequence */ char buff[UTF8BUFFSZ]; int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long))); pushstr(L, buff + UTF8BUFFSZ - l, l); break; } case '%': { pushstr(L, "%", 1); break; } default: { luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'", *(e + 1)); } } n += 2; fmt = e+2; } luaD_checkstack(L, 1); pushstr(L, fmt, strlen(fmt)); if (n > 0) luaV_concat(L, n + 1); return svalue(s2v(L->top - 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; } /* number of chars of a literal string without the ending \0 */ #define LL(x) (sizeof(x)/sizeof(char) - 1) #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 bufflen) { size_t l = strlen(source); if (*source == '=') { /* 'literal' source */ if (l <= bufflen) /* small enough? */ memcpy(out, source + 1, l * sizeof(char)); else { /* truncate it */ addstr(out, source + 1, bufflen - 1); *out = '\0'; } } else if (*source == '@') { /* file name */ if (l <= bufflen) /* small enough? */ memcpy(out, source + 1, l * sizeof(char)); else { /* add '...' before rest of name */ addstr(out, RETS, LL(RETS)); bufflen -= LL(RETS); memcpy(out, source + 1 + l - 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 (l < bufflen && nl == NULL) { /* small one-line source? */ addstr(out, source, l); /* keep it */ } else { if (nl != NULL) l = nl - source; /* stop at first newline */ if (l > bufflen) l = bufflen; addstr(out, source, l); addstr(out, RETS, LL(RETS)); } memcpy(out, POS, (LL(POS) + 1) * sizeof(char)); } }