/*** $Id: lvm.c,v 2.232 2014/12/27 20:30:38 roberto Exp $** Lua virtual machine** See Copyright Notice in lua.h*/ #define lvm_c#define LUA_CORE #include "lprefix.h" #include <limits.h>#include <stdio.h>#include <stdlib.h>#include <string.h> #include "lua.h" #include "ldebug.h"#include "ldo.h"#include "lfunc.h"#include "lgc.h"#include "lobject.h"#include "lopcodes.h"#include "lstate.h"#include "lstring.h"#include "ltable.h"#include "ltm.h"#include "lvm.h" /*** You can define LUA_FLOORN2I if you want to convert floats to integers** by flooring them (instead of raising an error if they are not** integral values)*/#if !defined(LUA_FLOORN2I)#define LUA_FLOORN2I 0#endif /* limit for table tag-method chains (to avoid loops) */#define MAXTAGLOOP 2000 /*** Similar to 'tonumber', but does not attempt to convert strings and** ensure correct precision (no extra bits). Used in comparisons.*/static int tofloat (const TValue *obj, lua_Number *n) { if (ttisfloat(obj)) *n = fltvalue(obj); else if (ttisinteger(obj)) { volatile lua_Number x = cast_num(ivalue(obj)); /* avoid extra precision */ *n = x; } else { *n = 0; /* to avoid warnings */ return 0; } return 1;} /*** Try to convert a value to a float. The float case is already handled** by the macro 'tonumber'.*/int luaV_tonumber_ (const TValue *obj, lua_Number *n) { TValue v; if (ttisinteger(obj)) { *n = cast_num(ivalue(obj)); return 1; } else if (cvt2num(obj) && /* string convertible to number? */ luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) { *n = nvalue(&v); /* convert result of 'luaO_str2num' to a float */ return 1; } else return 0; /* conversion failed */} /*** try to convert a value to an integer, rounding according to 'mode':** mode == 0: accepts only integral values** mode == 1: takes the floor of the number** mode == 2: takes the ceil of the number*/static int tointeger_aux (const TValue *obj, lua_Integer *p, int mode) { TValue v; again: if (ttisfloat(obj)) { lua_Number n = fltvalue(obj); lua_Number f = l_floor(n); if (n != f) { /* not an integral value? */ if (mode == 0) return 0; /* fails if mode demands integral value */ else if (mode > 1) /* needs ceil? */ f += 1; /* convert floor to ceil (remember: n != f) */ } return lua_numbertointeger(f, p); } else if (ttisinteger(obj)) { *p = ivalue(obj); return 1; } else if (cvt2num(obj) && luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) { obj = &v; goto again; /* convert result from 'luaO_str2num' to an integer */ } return 0; /* conversion failed */} /*** try to convert a value to an integer*/int luaV_tointeger_ (const TValue *obj, lua_Integer *p) { return tointeger_aux(obj, p, LUA_FLOORN2I);} /*** Try to convert a 'for' limit to an integer, preserving the** semantics of the loop.** (The following explanation assumes a non-negative step; it is valid** for negative steps mutatis mutandis.)** If the limit can be converted to an integer, rounding down, that is** it.** Otherwise, check whether the limit can be converted to a number. If** the number is too large, it is OK to set the limit as LUA_MAXINTEGER,** which means no limit. If the number is too negative, the loop** should not run, because any initial integer value is larger than the** limit. So, it sets the limit to LUA_MININTEGER. 'stopnow' corrects** the extreme case when the initial value is LUA_MININTEGER, in which** case the LUA_MININTEGER limit would still run the loop once.*/static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step, int *stopnow) { *stopnow = 0; /* usually, let loops run */ if (!tointeger_aux(obj, p, (step < 0 ? 2 : 1))) { /* not fit in integer? */ lua_Number n; /* try to convert to float */ if (!tonumber(obj, &n)) /* cannot convert to float? */ return 0; /* not a number */ if (n > 0) { /* if true, float is larger than max integer */ *p = LUA_MAXINTEGER; if (step < 0) *stopnow = 1; } else { /* float is smaller than min integer */ *p = LUA_MININTEGER; if (step >= 0) *stopnow = 1; } } return 1;} /*** Main function for table access (invoking metamethods if needed).** Compute 'val = t[key]'*/void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) { int loop; /* counter to avoid infinite loops */ for (loop = 0; loop < MAXTAGLOOP; loop++) { const TValue *tm; if (ttistable(t)) { /* 't' is a table? */ Table *h = hvalue(t); const TValue *res = luaH_get(h, key); /* do a primitive get */ if (!ttisnil(res) || /* result is not nil? */ (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */ setobj2s(L, val, res); /* result is the raw get */ return; } /* else will try metamethod */ } else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX))) luaG_typeerror(L, t, "index"); /* no metamethod */ if (ttisfunction(tm)) { /* metamethod is a function */ luaT_callTM(L, tm, t, key, val, 1); return; } t = tm; /* else repeat access over 'tm' */ } luaG_runerror(L, "gettable chain too long; possible loop");} /*** Main function for table assignment (invoking metamethods if needed).** Compute 't[key] = val'*/void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) { int loop; /* counter to avoid infinite loops */ for (loop = 0; loop < MAXTAGLOOP; loop++) { const TValue *tm; if (ttistable(t)) { /* 't' is a table? */ Table *h = hvalue(t); TValue *oldval = cast(TValue *, luaH_get(h, key)); /* if previous value is not nil, there must be a previous entry in the table; a metamethod has no relevance */ if (!ttisnil(oldval) || /* previous value is nil; must check the metamethod */ ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL && /* no metamethod; is there a previous entry in the table? */ (oldval != luaO_nilobject || /* no previous entry; must create one. (The next test is always true; we only need the assignment.) */ (oldval = luaH_newkey(L, h, key), 1)))) { /* no metamethod and (now) there is an entry with given key */ setobj2t(L, oldval, val); /* assign new value to that entry */ invalidateTMcache(h); luaC_barrierback(L, h, val); return; } /* else will try the metamethod */ } else /* not a table; check metamethod */ if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX))) luaG_typeerror(L, t, "index"); /* try the metamethod */ if (ttisfunction(tm)) { luaT_callTM(L, tm, t, key, val, 0); return; } t = tm; /* else repeat assignment over 'tm' */ } luaG_runerror(L, "settable chain too long; possible loop");} /*** Compare two strings 'ls' x 'rs', returning an integer smaller-equal-** -larger than zero if 'ls' is smaller-equal-larger than 'rs'.** The code is a little tricky because it allows '\0' in the strings** and it uses 'strcoll' (to respect locales) for each segments** of the strings.*/static int l_strcmp (const TString *ls, const TString *rs) { const char *l = getstr(ls); size_t ll = ls->len; const char *r = getstr(rs); size_t lr = rs->len; for (;;) { /* for each segment */ int temp = strcoll(l, r); if (temp != 0) /* not equal? */ return temp; /* done */ else { /* strings are equal up to a '\0' */ size_t len = strlen(l); /* index of first '\0' in both strings */ if (len == lr) /* 'rs' is finished? */ return (len == ll) ? 0 : 1; /* check 'ls' */ else if (len == ll) /* 'ls' is finished? */ return -1; /* 'ls' is smaller than 'rs' ('rs' is not finished) */ /* both strings longer than 'len'; go on comparing after the '\0' */ len++; l += len; ll -= len; r += len; lr -= len; } }} /*** Main operation less than; return 'l < r'.*/int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) { int res; lua_Number nl, nr; if (ttisinteger(l) && ttisinteger(r)) /* both operands are integers? */ return (ivalue(l) < ivalue(r)); else if (tofloat(l, &nl) && tofloat(r, &nr)) /* both are numbers? */ return luai_numlt(nl, nr); else if (ttisstring(l) && ttisstring(r)) /* both are strings? */ return l_strcmp(tsvalue(l), tsvalue(r)) < 0; else if ((res = luaT_callorderTM(L, l, r, TM_LT)) < 0) /* no metamethod? */ luaG_ordererror(L, l, r); /* error */ return res;} /*** Main operation less than or equal to; return 'l <= r'.*/int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) { int res; lua_Number nl, nr; if (ttisinteger(l) && ttisinteger(r)) /* both operands are integers? */ return (ivalue(l) <= ivalue(r)); else if (tofloat(l, &nl) && tofloat(r, &nr)) /* both are numbers? */ return luai_numle(nl, nr); else if (ttisstring(l) && ttisstring(r)) /* both are strings? */ return l_strcmp(tsvalue(l), tsvalue(r)) <= 0; else if ((res = luaT_callorderTM(L, l, r, TM_LE)) >= 0) /* first try 'le' */ return res; else if ((res = luaT_callorderTM(L, r, l, TM_LT)) < 0) /* else try 'lt' */ luaG_ordererror(L, l, r); return !res;} /*** Main operation for equality of Lua values; return 't1 == t2'. ** L == NULL means raw equality (no metamethods)*/int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) { const TValue *tm; if (ttype(t1) != ttype(t2)) { /* not the same variant? */ if (ttnov(t1) != ttnov(t2) || ttnov(t1) != LUA_TNUMBER) return 0; /* only numbers can be equal with different variants */ else { /* two numbers with different variants */ lua_Number n1, n2; /* compare them as floats */ lua_assert(ttisnumber(t1) && ttisnumber(t2)); cast_void(tofloat(t1, &n1)); cast_void(tofloat(t2, &n2)); return luai_numeq(n1, n2); } } /* values have same type and same variant */ switch (ttype(t1)) { case LUA_TNIL: return 1; case LUA_TNUMINT: return (ivalue(t1) == ivalue(t2)); case LUA_TNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2)); case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */ case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2); case LUA_TLCF: return fvalue(t1) == fvalue(t2); case LUA_TSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2)); case LUA_TLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2)); case LUA_TUSERDATA: { if (uvalue(t1) == uvalue(t2)) return 1; else if (L == NULL) return 0; tm = fasttm(L, uvalue(t1)->metatable, TM_EQ); if (tm == NULL) tm = fasttm(L, uvalue(t2)->metatable, TM_EQ); break; /* will try TM */ } case LUA_TTABLE: { if (hvalue(t1) == hvalue(t2)) return 1; else if (L == NULL) return 0; tm = fasttm(L, hvalue(t1)->metatable, TM_EQ); if (tm == NULL) tm = fasttm(L, hvalue(t2)->metatable, TM_EQ); break; /* will try TM */ } default: return gcvalue(t1) == gcvalue(t2); } if (tm == NULL) /* no TM? */ return 0; /* objects are different */ luaT_callTM(L, tm, t1, t2, L->top, 1); /* call TM */ return !l_isfalse(L->top);} /* macro used by 'luaV_concat' to ensure that element at 'o' is a string */#define tostring(L,o) \ (ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1))) /*** Main operation for concatenation: concat 'total' values in the stack,** from 'L->top - total' up to 'L->top - 1'.*/void luaV_concat (lua_State *L, int total) { lua_assert(total >= 2); do { StkId top = L->top; int n = 2; /* number of elements handled in this pass (at least 2) */ if (!(ttisstring(top-2) || cvt2str(top-2)) || !tostring(L, top-1)) luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT); else if (tsvalue(top-1)->len == 0) /* second operand is empty? */ cast_void(tostring(L, top - 2)); /* result is first operand */ else if (ttisstring(top-2) && tsvalue(top-2)->len == 0) { setobjs2s(L, top - 2, top - 1); /* result is second op. */ } else { /* at least two non-empty string values; get as many as possible */ size_t tl = tsvalue(top-1)->len; char *buffer; int i; /* collect total length */ for (i = 1; i < total && tostring(L, top-i-1); i++) { size_t l = tsvalue(top-i-1)->len; if (l >= (MAX_SIZE/sizeof(char)) - tl) luaG_runerror(L, "string length overflow"); tl += l; } buffer = luaZ_openspace(L, &G(L)->buff, tl); tl = 0; n = i; do { /* copy all strings to buffer */ size_t l = tsvalue(top-i)->len; memcpy(buffer+tl, svalue(top-i), l * sizeof(char)); tl += l; } while (--i > 0); setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl)); /* create result */ } total -= n-1; /* got 'n' strings to create 1 new */ L->top -= n-1; /* popped 'n' strings and pushed one */ } while (total > 1); /* repeat until only 1 result left */} /*** Main operation 'ra' = #rb'.*/void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) { const TValue *tm; switch (ttnov(rb)) { case LUA_TTABLE: { Table *h = hvalue(rb); tm = fasttm(L, h->metatable, TM_LEN); if (tm) break; /* metamethod? break switch to call it */ setivalue(ra, luaH_getn(h)); /* else primitive len */ return; } case LUA_TSTRING: { setivalue(ra, tsvalue(rb)->len); return; } default: { /* try metamethod */ tm = luaT_gettmbyobj(L, rb, TM_LEN); if (ttisnil(tm)) /* no metamethod? */ luaG_typeerror(L, rb, "get length of"); break; } } luaT_callTM(L, tm, rb, rb, ra, 1);} /*** Integer division; return 'm // n', that is, floor(m/n).** C division truncates its result (rounds towards zero).** 'floor(q) == trunc(q)' when 'q >= 0' or when 'q' is integer,** otherwise 'floor(q) == trunc(q) - 1'.*/lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) { if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */ if (n == 0) luaG_runerror(L, "attempt to divide by zero"); return intop(-, 0, m); /* n==-1; avoid overflow with 0x80000...//-1 */ } else { lua_Integer q = m / n; /* perform C division */ if ((m ^ n) < 0 && m % n != 0) /* 'm/n' would be negative non-integer? */ q -= 1; /* correct result for different rounding */ return q; }} /*** Integer modulus; return 'm % n'. (Assume that C '%' with ** negative operands follows C99 behavior. See previous comment** about luaV_div.)*/lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) { if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */ if (n == 0) luaG_runerror(L, "attempt to perform 'n%%0'"); return 0; /* m % -1 == 0; avoid overflow with 0x80000...%-1 */ } else { lua_Integer r = m % n; if (r != 0 && (m ^ n) < 0) /* 'm/n' would be non-integer negative? */ r += n; /* correct result for different rounding */ return r; }} /* number of bits in an integer */#define NBITS cast_int(sizeof(lua_Integer) * CHAR_BIT) /*** Shift left operation. (Shift right just negates 'y'.)*/lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) { if (y < 0) { /* shift right? */ if (y <= -NBITS) return 0; else return intop(>>, x, -y); } else { /* shift left */ if (y >= NBITS) return 0; else return intop(<<, x, y); }} /*** check whether cached closure in prototype 'p' may be reused, that is,** whether there is a cached closure with the same upvalues needed by** new closure to be created.*/static LClosure *getcached (Proto *p, UpVal **encup, StkId base) { LClosure *c = p->cache; if (c != NULL) { /* is there a cached closure? */ int nup = p->sizeupvalues; Upvaldesc *uv = p->upvalues; int i; for (i = 0; i < nup; i++) { /* check whether it has right upvalues */ TValue *v = uv[i].instack ? base + uv[i].idx : encup[uv[i].idx]->v;Lines 1–500 of 1182. Load more
/* ** $Id: lvm.c,v 2.232 2014/12/27 20:30:38 roberto Exp $ ** Lua virtual machine ** See Copyright Notice in lua.h */ #define lvm_c #define LUA_CORE #include "lprefix.h" #include <limits.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include "lua.h" #include "ldebug.h" #include "ldo.h" #include "lfunc.h" #include "lgc.h" #include "lobject.h" #include "lopcodes.h" #include "lstate.h" #include "lstring.h" #include "ltable.h" #include "ltm.h" #include "lvm.h" /* ** You can define LUA_FLOORN2I if you want to convert floats to integers ** by flooring them (instead of raising an error if they are not ** integral values) */ #if !defined(LUA_FLOORN2I) #define LUA_FLOORN2I 0 #endif /* limit for table tag-method chains (to avoid loops) */ #define MAXTAGLOOP 2000 /* ** Similar to 'tonumber', but does not attempt to convert strings and ** ensure correct precision (no extra bits). Used in comparisons. */ static int tofloat (const TValue *obj, lua_Number *n) { if (ttisfloat(obj)) *n = fltvalue(obj); else if (ttisinteger(obj)) { volatile lua_Number x = cast_num(ivalue(obj)); /* avoid extra precision */ *n = x; } else { *n = 0; /* to avoid warnings */ return 0; } return 1; } /* ** Try to convert a value to a float. The float case is already handled ** by the macro 'tonumber'. */ int luaV_tonumber_ (const TValue *obj, lua_Number *n) { TValue v; if (ttisinteger(obj)) { *n = cast_num(ivalue(obj)); return 1; } else if (cvt2num(obj) && /* string convertible to number? */ luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) { *n = nvalue(&v); /* convert result of 'luaO_str2num' to a float */ return 1; } else return 0; /* conversion failed */ } /* ** try to convert a value to an integer, rounding according to 'mode': ** mode == 0: accepts only integral values ** mode == 1: takes the floor of the number ** mode == 2: takes the ceil of the number */ static int tointeger_aux (const TValue *obj, lua_Integer *p, int mode) { TValue v; again: if (ttisfloat(obj)) { lua_Number n = fltvalue(obj); lua_Number f = l_floor(n); if (n != f) { /* not an integral value? */ if (mode == 0) return 0; /* fails if mode demands integral value */ else if (mode > 1) /* needs ceil? */ f += 1; /* convert floor to ceil (remember: n != f) */ } return lua_numbertointeger(f, p); } else if (ttisinteger(obj)) { *p = ivalue(obj); return 1; } else if (cvt2num(obj) && luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) { obj = &v; goto again; /* convert result from 'luaO_str2num' to an integer */ } return 0; /* conversion failed */ } /* ** try to convert a value to an integer */ int luaV_tointeger_ (const TValue *obj, lua_Integer *p) { return tointeger_aux(obj, p, LUA_FLOORN2I); } /* ** Try to convert a 'for' limit to an integer, preserving the ** semantics of the loop. ** (The following explanation assumes a non-negative step; it is valid ** for negative steps mutatis mutandis.) ** If the limit can be converted to an integer, rounding down, that is ** it. ** Otherwise, check whether the limit can be converted to a number. If ** the number is too large, it is OK to set the limit as LUA_MAXINTEGER, ** which means no limit. If the number is too negative, the loop ** should not run, because any initial integer value is larger than the ** limit. So, it sets the limit to LUA_MININTEGER. 'stopnow' corrects ** the extreme case when the initial value is LUA_MININTEGER, in which ** case the LUA_MININTEGER limit would still run the loop once. */ static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step, int *stopnow) { *stopnow = 0; /* usually, let loops run */ if (!tointeger_aux(obj, p, (step < 0 ? 2 : 1))) { /* not fit in integer? */ lua_Number n; /* try to convert to float */ if (!tonumber(obj, &n)) /* cannot convert to float? */ return 0; /* not a number */ if (n > 0) { /* if true, float is larger than max integer */ *p = LUA_MAXINTEGER; if (step < 0) *stopnow = 1; } else { /* float is smaller than min integer */ *p = LUA_MININTEGER; if (step >= 0) *stopnow = 1; } } return 1; } /* ** Main function for table access (invoking metamethods if needed). ** Compute 'val = t[key]' */ void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) { int loop; /* counter to avoid infinite loops */ for (loop = 0; loop < MAXTAGLOOP; loop++) { const TValue *tm; if (ttistable(t)) { /* 't' is a table? */ Table *h = hvalue(t); const TValue *res = luaH_get(h, key); /* do a primitive get */ if (!ttisnil(res) || /* result is not nil? */ (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */ setobj2s(L, val, res); /* result is the raw get */ return; } /* else will try metamethod */ } else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX))) luaG_typeerror(L, t, "index"); /* no metamethod */ if (ttisfunction(tm)) { /* metamethod is a function */ luaT_callTM(L, tm, t, key, val, 1); return; } t = tm; /* else repeat access over 'tm' */ } luaG_runerror(L, "gettable chain too long; possible loop"); } /* ** Main function for table assignment (invoking metamethods if needed). ** Compute 't[key] = val' */ void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) { int loop; /* counter to avoid infinite loops */ for (loop = 0; loop < MAXTAGLOOP; loop++) { const TValue *tm; if (ttistable(t)) { /* 't' is a table? */ Table *h = hvalue(t); TValue *oldval = cast(TValue *, luaH_get(h, key)); /* if previous value is not nil, there must be a previous entry in the table; a metamethod has no relevance */ if (!ttisnil(oldval) || /* previous value is nil; must check the metamethod */ ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL && /* no metamethod; is there a previous entry in the table? */ (oldval != luaO_nilobject || /* no previous entry; must create one. (The next test is always true; we only need the assignment.) */ (oldval = luaH_newkey(L, h, key), 1)))) { /* no metamethod and (now) there is an entry with given key */ setobj2t(L, oldval, val); /* assign new value to that entry */ invalidateTMcache(h); luaC_barrierback(L, h, val); return; } /* else will try the metamethod */ } else /* not a table; check metamethod */ if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX))) luaG_typeerror(L, t, "index"); /* try the metamethod */ if (ttisfunction(tm)) { luaT_callTM(L, tm, t, key, val, 0); return; } t = tm; /* else repeat assignment over 'tm' */ } luaG_runerror(L, "settable chain too long; possible loop"); } /* ** Compare two strings 'ls' x 'rs', returning an integer smaller-equal- ** -larger than zero if 'ls' is smaller-equal-larger than 'rs'. ** The code is a little tricky because it allows '\0' in the strings ** and it uses 'strcoll' (to respect locales) for each segments ** of the strings. */ static int l_strcmp (const TString *ls, const TString *rs) { const char *l = getstr(ls); size_t ll = ls->len; const char *r = getstr(rs); size_t lr = rs->len; for (;;) { /* for each segment */ int temp = strcoll(l, r); if (temp != 0) /* not equal? */ return temp; /* done */ else { /* strings are equal up to a '\0' */ size_t len = strlen(l); /* index of first '\0' in both strings */ if (len == lr) /* 'rs' is finished? */ return (len == ll) ? 0 : 1; /* check 'ls' */ else if (len == ll) /* 'ls' is finished? */ return -1; /* 'ls' is smaller than 'rs' ('rs' is not finished) */ /* both strings longer than 'len'; go on comparing after the '\0' */ len++; l += len; ll -= len; r += len; lr -= len; } } } /* ** Main operation less than; return 'l < r'. */ int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) { int res; lua_Number nl, nr; if (ttisinteger(l) && ttisinteger(r)) /* both operands are integers? */ return (ivalue(l) < ivalue(r)); else if (tofloat(l, &nl) && tofloat(r, &nr)) /* both are numbers? */ return luai_numlt(nl, nr); else if (ttisstring(l) && ttisstring(r)) /* both are strings? */ return l_strcmp(tsvalue(l), tsvalue(r)) < 0; else if ((res = luaT_callorderTM(L, l, r, TM_LT)) < 0) /* no metamethod? */ luaG_ordererror(L, l, r); /* error */ return res; } /* ** Main operation less than or equal to; return 'l <= r'. */ int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) { int res; lua_Number nl, nr; if (ttisinteger(l) && ttisinteger(r)) /* both operands are integers? */ return (ivalue(l) <= ivalue(r)); else if (tofloat(l, &nl) && tofloat(r, &nr)) /* both are numbers? */ return luai_numle(nl, nr); else if (ttisstring(l) && ttisstring(r)) /* both are strings? */ return l_strcmp(tsvalue(l), tsvalue(r)) <= 0; else if ((res = luaT_callorderTM(L, l, r, TM_LE)) >= 0) /* first try 'le' */ return res; else if ((res = luaT_callorderTM(L, r, l, TM_LT)) < 0) /* else try 'lt' */ luaG_ordererror(L, l, r); return !res; } /* ** Main operation for equality of Lua values; return 't1 == t2'. ** L == NULL means raw equality (no metamethods) */ int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) { const TValue *tm; if (ttype(t1) != ttype(t2)) { /* not the same variant? */ if (ttnov(t1) != ttnov(t2) || ttnov(t1) != LUA_TNUMBER) return 0; /* only numbers can be equal with different variants */ else { /* two numbers with different variants */ lua_Number n1, n2; /* compare them as floats */ lua_assert(ttisnumber(t1) && ttisnumber(t2)); cast_void(tofloat(t1, &n1)); cast_void(tofloat(t2, &n2)); return luai_numeq(n1, n2); } } /* values have same type and same variant */ switch (ttype(t1)) { case LUA_TNIL: return 1; case LUA_TNUMINT: return (ivalue(t1) == ivalue(t2)); case LUA_TNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2)); case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */ case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2); case LUA_TLCF: return fvalue(t1) == fvalue(t2); case LUA_TSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2)); case LUA_TLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2)); case LUA_TUSERDATA: { if (uvalue(t1) == uvalue(t2)) return 1; else if (L == NULL) return 0; tm = fasttm(L, uvalue(t1)->metatable, TM_EQ); if (tm == NULL) tm = fasttm(L, uvalue(t2)->metatable, TM_EQ); break; /* will try TM */ } case LUA_TTABLE: { if (hvalue(t1) == hvalue(t2)) return 1; else if (L == NULL) return 0; tm = fasttm(L, hvalue(t1)->metatable, TM_EQ); if (tm == NULL) tm = fasttm(L, hvalue(t2)->metatable, TM_EQ); break; /* will try TM */ } default: return gcvalue(t1) == gcvalue(t2); } if (tm == NULL) /* no TM? */ return 0; /* objects are different */ luaT_callTM(L, tm, t1, t2, L->top, 1); /* call TM */ return !l_isfalse(L->top); } /* macro used by 'luaV_concat' to ensure that element at 'o' is a string */ #define tostring(L,o) \ (ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1))) /* ** Main operation for concatenation: concat 'total' values in the stack, ** from 'L->top - total' up to 'L->top - 1'. */ void luaV_concat (lua_State *L, int total) { lua_assert(total >= 2); do { StkId top = L->top; int n = 2; /* number of elements handled in this pass (at least 2) */ if (!(ttisstring(top-2) || cvt2str(top-2)) || !tostring(L, top-1)) luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT); else if (tsvalue(top-1)->len == 0) /* second operand is empty? */ cast_void(tostring(L, top - 2)); /* result is first operand */ else if (ttisstring(top-2) && tsvalue(top-2)->len == 0) { setobjs2s(L, top - 2, top - 1); /* result is second op. */ } else { /* at least two non-empty string values; get as many as possible */ size_t tl = tsvalue(top-1)->len; char *buffer; int i; /* collect total length */ for (i = 1; i < total && tostring(L, top-i-1); i++) { size_t l = tsvalue(top-i-1)->len; if (l >= (MAX_SIZE/sizeof(char)) - tl) luaG_runerror(L, "string length overflow"); tl += l; } buffer = luaZ_openspace(L, &G(L)->buff, tl); tl = 0; n = i; do { /* copy all strings to buffer */ size_t l = tsvalue(top-i)->len; memcpy(buffer+tl, svalue(top-i), l * sizeof(char)); tl += l; } while (--i > 0); setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl)); /* create result */ } total -= n-1; /* got 'n' strings to create 1 new */ L->top -= n-1; /* popped 'n' strings and pushed one */ } while (total > 1); /* repeat until only 1 result left */ } /* ** Main operation 'ra' = #rb'. */ void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) { const TValue *tm; switch (ttnov(rb)) { case LUA_TTABLE: { Table *h = hvalue(rb); tm = fasttm(L, h->metatable, TM_LEN); if (tm) break; /* metamethod? break switch to call it */ setivalue(ra, luaH_getn(h)); /* else primitive len */ return; } case LUA_TSTRING: { setivalue(ra, tsvalue(rb)->len); return; } default: { /* try metamethod */ tm = luaT_gettmbyobj(L, rb, TM_LEN); if (ttisnil(tm)) /* no metamethod? */ luaG_typeerror(L, rb, "get length of"); break; } } luaT_callTM(L, tm, rb, rb, ra, 1); } /* ** Integer division; return 'm // n', that is, floor(m/n). ** C division truncates its result (rounds towards zero). ** 'floor(q) == trunc(q)' when 'q >= 0' or when 'q' is integer, ** otherwise 'floor(q) == trunc(q) - 1'. */ lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) { if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */ if (n == 0) luaG_runerror(L, "attempt to divide by zero"); return intop(-, 0, m); /* n==-1; avoid overflow with 0x80000...//-1 */ } else { lua_Integer q = m / n; /* perform C division */ if ((m ^ n) < 0 && m % n != 0) /* 'm/n' would be negative non-integer? */ q -= 1; /* correct result for different rounding */ return q; } } /* ** Integer modulus; return 'm % n'. (Assume that C '%' with ** negative operands follows C99 behavior. See previous comment ** about luaV_div.) */ lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) { if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */ if (n == 0) luaG_runerror(L, "attempt to perform 'n%%0'"); return 0; /* m % -1 == 0; avoid overflow with 0x80000...%-1 */ } else { lua_Integer r = m % n; if (r != 0 && (m ^ n) < 0) /* 'm/n' would be non-integer negative? */ r += n; /* correct result for different rounding */ return r; } } /* number of bits in an integer */ #define NBITS cast_int(sizeof(lua_Integer) * CHAR_BIT) /* ** Shift left operation. (Shift right just negates 'y'.) */ lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) { if (y < 0) { /* shift right? */ if (y <= -NBITS) return 0; else return intop(>>, x, -y); } else { /* shift left */ if (y >= NBITS) return 0; else return intop(<<, x, y); } } /* ** check whether cached closure in prototype 'p' may be reused, that is, ** whether there is a cached closure with the same upvalues needed by ** new closure to be created. */ static LClosure *getcached (Proto *p, UpVal **encup, StkId base) { LClosure *c = p->cache; if (c != NULL) { /* is there a cached closure? */ int nup = p->sizeupvalues; Upvaldesc *uv = p->upvalues; int i; for (i = 0; i < nup; i++) { /* check whether it has right upvalues */ TValue *v = uv[i].instack ? base + uv[i].idx : encup[uv[i].idx]->v;